Journal articles on the topic 'Intraclonal heterogeneity'
To see the other types of publications on this topic, follow the link: Intraclonal heterogeneity.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Intraclonal heterogeneity.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Beke, Allan, Lucie Laplane, Julie Riviere, Qin Yang, Miguel Torres-Martin, Thibault Dayris, Philippe Rameau, et al. "Multilayer intraclonal heterogeneity in chronic myelomonocytic leukemia." Haematologica 105, no. 1 (May 2, 2019): 112–23. http://dx.doi.org/10.3324/haematol.2018.208488.
Full text
2
Zojer, Niklas, Heinz Ludwig, Michael Fiegl, Freda K. Stevenson, and Surinder S. Sahota. "Patterns of somatic mutations in VH genes reveal pathways of clonal transformation from MGUS to multiple myeloma." Blood 101, no. 10 (May 15, 2003): 4137–39. http://dx.doi.org/10.1182/blood-2002-09-2825.
Full textAbstract:
AbstractMonoclonal gammopathy of undetermined significance (MGUS) can transform to multiple myeloma (MM). In myeloma, mutated VHgenes with sequence homogeneity reveal a postfollicular origin. Previously, some MGUS cases showed mutated VH genes with intraclonal variation, indicating an earlier stage of arrest. We investigated progression from 2 of 2 MGUS to MM, in which VH genes confirmed clonal evolution. In one MGUS case, intraclonal heterogeneity was evident, and transformation to myeloma occurred rapidly with apparent homogeneity in the emergent clone. However, residual MGUS-derived sequences were detectable at this time. Heterogeneity in MGUS does not associate with benign disease, but it indicates an origin from a tumorigenic cell, most likely surface immunoglobulin+, undergoing somatic mutation. The remaining case displayed intraclonal homogeneity at the MGUS stage, conceivably resulting from a self-cloning outgrowth from MGUS with heterogeneity. Transformation can occur at either MGUS stage, but it involves a single cell in which somatic mutation is then silent.
3
Pilbrough, Warren, Trent P. Munro, and Peter Gray. "Intraclonal Protein Expression Heterogeneity in Recombinant CHO Cells." PLoS ONE 4, no. 12 (December 23, 2009): e8432. http://dx.doi.org/10.1371/journal.pone.0008432.
Full text
4
Puig, Noemi, Isabel Conde, Cristina Jimenez, Maria E. Sarasquete, Ana Balanzategui, Miguel Alcoceba, Jonathan Quintero, et al. "Intraclonal Heterogeneity Associates with Clonal Stability in Multiple Myeloma." Blood 124, no. 21 (December 6, 2014): 3412. http://dx.doi.org/10.1182/blood.v124.21.3412.3412.
Full textAbstract:
Abstract Multiple myeloma (MM) pathogenesis has been explained for many years by the cancer biology dogma introduced by Peter Nowell: first, a single plasma cell would be immortalized by an error in the immunoglobulin genes rearrangement process; then, a progressive stepwise acquisition of somatic cell mutations would induce a sequential selection and domination by the fittest clone. In line with this idea of “myeloma stability”, SNP arrays studies in diagnostic-relapse paired samples have revealed the presence of common clonal characteristics. Biologically, the M-protein remains usually constant across MM evolution and further, the variable domain of the rearranged immunoglobulin heavy chain genes (or CDR3 region) has been used as a patient-specific myeloma fingerprint in minimal residual disease (MRD) studies. However, massive genome studies with Next Generation Sequencing (NGS) have challenged this concept, showing a significant intraclonal heterogeneity at diagnosis with the possible presence of several clonal progenitors or tumor-initiating cells. In this study, we have characterized and compared the CDR3 region in 52-paired samples from 26 MM patients aiming: 1) to assess mono-clonality in MM evolution through the analysis of the CDR3 sequence and, 2) to validate ASO RQ-PCR approaches for MRD in MM, based on the constancy and specificity of the CDR3 region. Samples were obtained at diagnosis and progression (19 pairs) or at 2 different timepoints of progressive disease (7 pairs). Median time between sampling was 2 years. M-protein subtype remained stable in all pairs but 1, associated with a light-chain escape phenomenon. All samples proceeded from bone marrow (BM) except for 2 pairs, composed by BM and extramedullary disease (spleen and testes). Two major cytogenetic changes were identified: increased 13q14 deletion (from 7 to 54%) in 1 pair and increased 17p (p53) deletion (from 5 to 87%) in a further one. Treatments administered between sampling included most of the current approaches used in MM (data not shown). Genomic DNA isolation, PCR amplification and sequencing were performed following conventional methods. Germline VH, DH and JH segments were identified by comparison with public databases. CDR3 region was first identified in all samples and then compared between the two samples in the 26 pairs: the sequence of nucleotides was constantly identical in each pair, including those associated with major cytogenetic changes, a light-chain escape, extramedullar vs. BM infiltration and relapsed (and therefore, treatment selected) vs. refractory disease. Therefore, we can first conclude that the main tumor clone in MM retains a specific signature across all stages of disease evolution that allows the identification of samples as evolutionary related. This major clone signature is not modified by clinical or biological changes in the disease nor under different treatment pressures and would thus identify disease relapse and progression. Our results have also a clear impact on the validity of molecular MRD techniques. The high rate of complete responses (up to 50-60%) currently achieved in MM has prompted the use of new techniques for disease assessment. Today, ASO RQ-PCR, based on the use of specific primers and probes complementary of the VDJH rearrangement, continues to be the most sensitive approach. One pitfall of this technique would be the potential instability of PCR targets over time, which would induce false negative results. In B-cell precursor ALL, this is estimated to happen in 30-40% of cases but has not been deeply evaluated in MM yet. With the present study, we can also conclude that the junction region of the VDJH rearrangement in MM constantly identifies the myeloma cells responsible for relapse and therefore can be used as a reliable target for MRD assessment by ASO RQ-PCR and more recently, by NGS methods. If the CDR3 region remains stable, the novel concept of clonal tiding in MM should not be interpreted as a poly- or oligoclonal but subclonal. In MM, tides can be subclonal, but the ocean remains monoclonal. Disclosures No relevant conflicts of interest to declare.
5
Ma, Wanlong, Maya Thangavelu, Ivan De Dios, Vincent Funari, and Maher Albitar. "Interclonal and Intraclonal Heterogeneity in Patients with IDH1/2 Mutation." Blood 128, no. 22 (December 2, 2016): 1689. http://dx.doi.org/10.1182/blood.v128.22.1689.1689.
Full textAbstract:
Abstract Background: DNA methylation in AML/MDS plays a major role in the pathogenesis of acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). The major genes involved in DNA methylation in AML/MDS are IDH1 and 2, TET2 and DNMT3A. Mutations in IDH1/2 result in the production of an aberrant metabolite, 2-hydroxyglutarate, which acts as a competitive inhibitor of a-ketoglutarate and inhibits TET2 oxidation of 5-methylcytosine to 5-hydroxymethylcytosine (5hmC). Mutations in TET2 or IDH1/2 are associated with reduced levels of 5hmC and genomic hypermethylation. TET2 mutations and IDH1/IDH2 mutations are believed to be mutually exclusive. In addition, DNMT3A as a DNA methyltransferase enzyme is commonly mutated in AML/MDS and its mutation is believed to lead to hypomethylation. Understanding the interaction between these genes may influence therapy with IDH1/2 inhibitors. Toward better understanding of interaction between these genes, we analyzed the mutation profile of these genes in patients with AML/MDS. Methods: A total of 1182 bone marrow (BM) aspirate samples were tested by the commercially available TruSight Myeloid Next Generation Sequencing Panel (Illumina, San Diego, CA). We extracted DNA from bone marrow aspirate using the QIAamp DNA Mini Kit. This NGS panel covers hot spot mutations in 54 genes. The average depth of sequencing was 10,000X. Results: IDH1/2 mutations were detected in 201 of the 1182 (17%). IDH1 was detected in 87 (7.4%) and IDH2 was detected in 120 (10.1%). This included 6 patients who had mutations in both IDH1 and IDH2. Variant (mutant) allele frequency (VAF) was significantly higher (P=0.01) in IDH2 as compared to IDH1 (median of 43.35% vs 35.0%, respectively). Thirteen patients (6.5%) had mutant VAF >50% suggesting homozygosity, 11 of which had IDH2 mutation. Two of the 6 patients with both IDH1 and IDH2 mutations had VAF <20%, raising the possibility of two independent clones. TET2 mutations were detected in 15 (7.5%) of the patients with IDH1/2 mutations. There was significant difference (P=0.03) in VAF between IDH1/2 and TET2. Nine of these patients showed comparable VAF while the other 6 patients showed completely different VAF, suggesting subclonal heterogeneity. In addition, 58 (29%) patients showed mutations in IDH1/2 and DNMT3A. While there was no significant difference in VAF between IDH1/2 and DNMT3A, VAF in IDH1/2 was >50% in 6 of these patient and in DNMT3A in 3 patients. Twenty four patients had TP53 mutation, of which 16 had IDH1 mutation and 8 had IDH2 mutation, which is disproportional with the prevalence of IDH1 mutation. There was no statistically significant difference in VAF between TP53 and IDH1/2, but 4 of these patients had both DNMT3 and IDH2 mutations and one had both IDH1 and IDH2 mutations. None of the patients with TP53 mutation had TET2 mutation. Conclusions: IDH2 mutations may coexist with IDH1 and TET2 mutations. This co-mutation appears to be in the same clone in some patients and in a separate clone in others. The presence of VAF>50% in 6.5% of patients, which suggests homozygosity, along with co-presence of IDH1 and IDH2 and TET2 mutations suggests possible dosage effects in the biology of MDS/AML. The high rate (29%) of co-presence of DNMT3A with IDH/1/2 mutations also suggests cooperation between the two mechanisms in influencing DNA methylation and leukemogenesis. The relatively high incidence of TP53 mutation in IDH1 patients suggests that IDH1 mutation might be associated with more aggressive disease than IDH2. This data suggests that there is interaction and significant interclonal and intraclonal heterogeneity in DNA methylation genes in AML/MDS. Complete profiling of these genes is necessary for better understanding and proper prediction of clinical behavior particularly when patients treated with DNA methylation inhibitors. Figure Figure. Disclosures Ma: Neogenomics Laboratories: Employment. Thangavelu:Neogenomics Laboratories: Employment. De Dios:Neogenomics Laboratories: Employment. Funari:Neogenomics Laboratories: Employment. Albitar:Neogenomics Laboratories: Employment, Equity Ownership.
6
Palucka, Karolina A., Eva Knaust, Dawei Xu, Barbara Macnamara, Anna Porwit-MacDonald, Astrid Gruber, Curt Peterson, Magnus Björkholm, and Pavel Pisa. "Intraclonal Heterogeneity in theIn VitroDaunorubicin-Induced Apoptosis in Acute Myeloid Leukemia." Leukemia & Lymphoma 32, no. 3-4 (January 1999): 309–16. http://dx.doi.org/10.3109/10428199909167391.
Full text
7
Thangavelu, Maya, Wanlong Ma, Steven Brodie, Christopher Mixon, Wayne Chen, Sally Agersborg, and Maher Albitar. "Interclonal and Intraclonal Heterogeneity in Patients with Early Myelodysplastic Syndrome (MDS)." Blood 126, no. 23 (December 3, 2015): 1670. http://dx.doi.org/10.1182/blood.v126.23.1670.1670.
Full textAbstract:
Abstract Introduction: Recent data suggest that MDS evolves by accumulating mutations. Early mutations may involve genes that require additional mutations prior to clinical manifestation as MDS. We explored if mutant allele burden and the relative mutation of one gene to another gene could provide information on the interclonal and intraclonal progression of MDS using next generation sequencing (NGS) in patients with early MDS. Methods: NGS data was generated from 96 patients diagnosed with MDS with marrow blast count <5% using a targeted sequencing covering mutations in the following genes: TET2, SF3B1, ASXL1, DNMT3A, SRSF2, RUNX1, NRAS, ZRSR2, EZH2, ETV6, TP53, CBL, NPM1, JAK2, U2AF1, IDH1, KRAS, IDH2, FLT3, PTPN11, SETBP1, and BCOR. The average depth of sequencing was 10,000X. Differences in mutant allele frequency between two genes in the same sample were considered significant if they were >10%. A difference of 10% to 20% was considered mild, 20%-30% moderate, and >30% severe. A heat map reflecting these differences in mutant allele frequency was generated. Results: In this group of early MDS patients, 63 patients (66%) had more than one gene mutated and 38 (40%) had a significant (>10%) difference in allele frequency. The median number of genes mutated was 2 (range 1 to 5). Difference in mutant allele frequency was severe in 15 patients (16%), intermediate in 15 patients (16%), and mild in 13 patients (14%). TET2 was the most commonly mutated gene (43 patients, 45%) and was rarely the sole mutation with most cases exhibiting a mutation in a second gene (39 patients, 91%). The mutant allele burden was highest in TET2 in 26 of these 39 patients (67%), reflecting early event in the tumorigenic process. Of the 13 cases with TET2 mutation and allele burden less than the companion gene, 6 had a mutation in SF3B1, 3 had significant cytogenetic abnormalities (monosomy 5, del(7q), and trisomy 8), 2 had a mutation in SRSF2, 1 had a mutation in ZRSR2 and 1 had a mutation in ASXL1, which suggests that these abnormalities might be the initiating event. A second TET mutation (biallelic mutation) was detected in 16 of the 39 patients. SF3B1 was the most common gene having a solitary mutation (10% of all patients), although mutation in SF3B1 was detected in 27 patients (26% of all patients). All solitary SF3B1 mutations were associated with normal karyotypes, except for one patient with del(11q). JAK2 was mutated with SF3B1 in two cases diagnosed as RARS-T (refractory anemia with ring sideroblasts and thrombocytosis). In one case, the JAK2 and SF3B1 mutation allele frequencies were similar, but in the other, the JAK2 mutant allele frequency was 23% higher, suggesting that a myeloproliferative neoplasm was the initiating process. ASXL1 was mutated in 14 cases, 13 of which had additional mutations. DNMT3A gene was mutated in 18 cases, 5 of which were solitary; two of these five showed cytogenetic abnormalities. TP53 was mutated in 13 cases, but except for one case, all had either mutation in another gene or a cytogenetic abnormality. Conclusion: These data suggest that in patients with clinically confirmed early MDS, TET2 mutations are most likely the initiating oncogenic event, but mutations in other genes or cytogenetic abnormalities most likely lead to clinically confirmed MDS. In contrast, patients with SF3B1 mutation can have clinical disease without additional mutations. Our data suggest that SRSF2, ZRSR2, and ASXL1 may initiate mutagenesis in patients with MDS. Figure 1. Figure 1. Disclosures No relevant conflicts of interest to declare.
8
Vasconcelos, Zilton, Sabina Müller, Delphine Guipouy, Wong Yu, Claire Christophe, Sébastien Gadat, Salvatore Valitutti, and Loïc Dupré. "Individual Human Cytotoxic T Lymphocytes Exhibit Intraclonal Heterogeneity during Sustained Killing." Cell Reports 11, no. 9 (June 2015): 1474–85. http://dx.doi.org/10.1016/j.celrep.2015.05.002.
Full text
9
Bartholdy, Boris A., Xiahoua Wang, Xiao-Jie Yan, Marién Pascual, Manxia Fan, Jacqueline Barrientos, Steven L. Allen, et al. "CLL intraclonal fractions exhibit established and recently acquired patterns of DNA methylation." Blood Advances 4, no. 5 (March 9, 2020): 893–905. http://dx.doi.org/10.1182/bloodadvances.2019000817.
Full textAbstract:
Abstract Intraclonal subpopulations of circulating chronic lymphocytic leukemia (CLL) cells with different proliferative histories and reciprocal surface expression of CXCR4 and CD5 have been observed in the peripheral blood of CLL patients and named proliferative (PF), intermediate (IF), and resting (RF) cellular fractions. Here, we found that these intraclonal circulating fractions share persistent DNA methylation signatures largely associated with the mutation status of the immunoglobulin heavy chain locus (IGHV) and their origins from distinct stages of differentiation of antigen-experienced B cells. Increased leukemic birth rate, however, showed a very limited impact on DNA methylation of circulating CLL fractions independent of IGHV mutation status. Additionally, DNA methylation heterogeneity increased as leukemic cells advanced from PF to RF in the peripheral blood. This frequently co-occurred with heterochromatin hypomethylation and hypermethylation of Polycomb-repressed regions in the PF, suggesting accumulation of longevity-associated epigenetic features in recently born cells. On the other hand, transcriptional differences between paired intraclonal fractions confirmed their proliferative experience and further supported a linear advancement from PF to RF in the peripheral blood. Several of these differentially expressed genes showed unique associations with clinical outcome not evident in the bulk clone, supporting the pathological and therapeutic relevance of studying intraclonal CLL fractions. We conclude that independent methylation and transcriptional landscapes reflect both preexisting cell-of-origin fingerprints and more recently acquired hallmarks associated with the life cycle of circulating CLL cells.
10
Conrad, C. A., J. Fueyo, and C. Gomez-Manzano. "Intratumoral heterogeneity and intraclonal plasticity: from warburg to oxygen and back again." Neuro-Oncology 16, no. 8 (July 6, 2014): 1025–26. http://dx.doi.org/10.1093/neuonc/nou121.
Full text
11
Gutiérrez, M. I., K. Bhatia, B. Cherney, D. Capello, G. Gaidano, and I. Magrath. "Intraclonal molecular heterogeneity suggests a hierarchy of pathogenetic events in Burkitt's lymphoma." Annals of Oncology 8, no. 10 (October 1997): 987–94. http://dx.doi.org/10.1023/a:1008265304712.
Full text
12
Calissano, Carlo, Rajendra N. Damle, Gregory Hayes, Elizabeth J. Murphy, Marc K. Hellerstein, Carol Moreno, Cristina Sison, et al. "In vivo intraclonal and interclonal kinetic heterogeneity in B-cell chronic lymphocytic leukemia." Blood 114, no. 23 (November 26, 2009): 4832–42. http://dx.doi.org/10.1182/blood-2009-05-219634.
Full textAbstract:
Abstract Clonal evolution and outgrowth of cellular variants with additional chromosomal abnormalities are major causes of disease progression in chronic lymphocytic leukemia (CLL). Because new DNA lesions occur during S phase, proliferating cells are at the core of this problem. In this study, we used in vivo deuterium (2H) labeling of CLL cells to better understand the phenotype of proliferating cells in 13 leukemic clones. In each case, there was heterogeneity in cellular proliferation, with a higher fraction of newly produced CD38+ cells compared with CD38− counterparts. On average, there were 2-fold higher percentages of newly born cells in the CD38+ fraction than in CD38− cells; when analyzed on an individual patient basis, CD38+2H-labeled cells ranged from 6.6% to 73%. Based on distinct kinetic patterns, interclonal heterogeneity was also observed. Specifically, 4 patients exhibited a delayed appearance of newly produced CD38+ cells in the blood, higher leukemic cell CXC chemokine receptor 4 (CXCR4) levels, and increased risk for lymphoid organ infiltration and poor outcome. Our data refine the proliferative compartment in CLL based on CD38 expression and suggest a relationship between in vivo kinetics, expression of a protein involved in CLL cell retention and trafficking to solid tissues, and clinical outcome.
13
Rawstron, Andy C., James A. L. Fenton, Marieth Plummer, Harry O. King, Fiona L. Bennett, Andrew S. Jack, and Peter Hillmen. "Monoclonal B-Cell Lymphocytosis (MBL) and CLL Show Intraclonal Variation: Cases Classified as “Unmutated” Have the Greatest Clonal Diversity." Blood 108, no. 11 (November 16, 2006): 30. http://dx.doi.org/10.1182/blood.v108.11.30.30.
Full textAbstract:
Abstract A monoclonal B-cell lymphocytosis (MBL) is detectable in approximately 3% of the general adult population. In most cases the abnormal cells have a phenotype and genotype that is indistinguishable from indolent CLL. Individuals presenting with an MBL count over 500 cells per microlitre progress to CLL requiring treatment at a rate of approximately 1% per year. The relationship between MBL and CLL therefore appears to be similar to that of MGUS and myeloma. Intraclonal variation (ICV) in the immunoglobulin heavy chain gene (IgVH) gene occurs in approximately half of MGUS patients but is not present in myeloma. The majority MGUS patients that progress to myeloma lack intraclonal variation at the MGUS stage suggesting that clonal selection is a critical pathway for disease progression in myeloma. The aim of this study was to compare the rate of intraclonal variation in MBL and CLL and determine whether low rates of ICV are associated with progressive disease. DNA was extracted from ammonium-chloride lysed blood samples from individuals with CLL-phenotype MBL (n=20) and CLL with progressive disease (n=10). IgVH and BCL6 PCR products were directly sequenced and also cloned and at least 10 clones sequenced. Intraclonal variation was defined as the number of unique sequences as a percentage of total clones sequenced. Unmutated CLL was defined as having <2% difference in the predominant IgVH clone sequence from germline. The median IgVH mutation rate in the MBL group was 7.4% (range 1.3–13.7%) and in the progressive CLL group 0.6% (range 0–11.3%). Intraclonal variation was observed in both groups of patients: the median number of unique clones was 2/10 (range 0–7/10) in MBL patients and 3/10 (range 0–5/10) in CLL patients. Intraclonal variation was generally restricted to 1 or 2 point mutations in each sequence and for the VH gene the replacement/silent (R/S) ratio of mutations was 1.7 in the framework regions and 3.3 in the complementarity-determining regions. Independent of disease category, unmutated CLL/MBL had a higher degree of intraclonal variation than mutated CLL with a median ICV for unmutated cases of 31% and for mutated cases of 20%. The proportion of patients showing complete clonal homogeneity was lower for unmutated CLL/MBL (14%) than mutated CLL/MBL (27%). The BCL6 gene, which is also mutated during the canonical somatic hypermutation process, showed similar results with a greater degree of intraclonal variation in unmutated CLL/MBL. The results demonstrate that intraclonal variation is a frequent occurrence in both MBL and CLL particularly when non-immunoglobulin genes are also considered. Clonal heterogeneity is either independent of, or inversely related to, the immunoglobulin mutation status demonstrating that both mutated and unmutated CLL have undergone (or are continuing to undergo) somatic hypermutation. The mechanisms of disease progression in MBL/CLL are clearly biologically distinct from MGUS/Myeloma and this data provides strong evidence for an antigen-driven selection process in CLL. Disease progression in CLL may therefore be the result of continued activity of the somatic hypermutation machinery, demonstrated by AID expression in some patients. Coupled with a selective pressure to maintain the immunoglobulin gene this process may result in the selection of CLL clones with transforming mutations in non-immunoglobulin genes.
14
Forconi, Francesco, T. Amato, D. Raspadori, S. S. Sahota, M. A. Dell’Aversano, M. Tassi, D. Rossi, et al. "VH and VL Genes in Hairy Cell Leukemia Reveal a Dynamic On-Going Modification of the Surface B-Cell Receptor." Blood 106, no. 11 (November 16, 2005): 287. http://dx.doi.org/10.1182/blood.v106.11.287.287.
Full textAbstract:
Abstract Immunoglobulin (Ig) gene analysis delineates critical features of the clonal history of a B-cell tumor. After antigen interaction, mature B-cells undergo somatic mutation of the V-genes and isotype switch recombination, generally in the germinal center (GC). Receptor revision by secondary recombination of the V-genes with re-expression of recombination activating gene (RAG) enzymes rarely occurs at this stage. From a small series, we have reported that most hairy cell leukemias (HCL) carry mutated VH genes, with low levels of intraclonal heterogeneity, while a minor subset have unmutated VH genes. Both subsets commonly have ongoing Ig isotype switch events and express activation induced cytidine deaminase (AID). However HCL lack the GC markers CD27 and CD38, and CD23, a chemokine essential for lymph node entry. In order to probe more fully the differentiation status of the cell of origin, both VH and VL tumor-derived genes were evaluated in an expanded series of 38 HCL. From analysis of VH, the VH3 family usage was most common (24/38, 63%), with significant preference of the VH3-30 member in 10/38 cases (26%, p=0,00001), and JH4b segment utilised in 50% of cases. Most HCL (35/38) carried variable tiers of mutations (87–98.6% homology to germline), with low level of intraclonal heterogeneity also in cases with <2% deviation from germline, while 3/38 (8%) displayed completely unmutated VH genes. Analysis of VL genes provided novel insights, when 21/38 HCL were evaluated. The λ light chain was most fequently used (13/21, 62%), to indicate preferential secondary rearrangement to λ chain. All λ cases used Jγ3 segment. Nineteen of 21 cases carried mutated VL genes (94,75%–99.6%) with low levels of intraclonal heterogeneity, while 2 cases carried completely unmutated VL genes, reflecting the status of the VH gene. Strikingly, in-frame functional secondary VL chain rearrangements were observed in the tumor cells of 2 of these cases (Vκ 1 and Vκ 2 in case R1, Vκ 1 and Vκ 2 in R2). Primary and secondary rearrangements showed mutations (98.1 and 99.6% homology in R1, 97.6 and 99.6% homology in R2). In both cases, RAG1 re-induction was identified by RT-PCR and sequence verification. Both cases expressed AID transcripts and displayed intraclonal mutations in the VH and/or the VL genes. These data suggest a dynamic, on-going modification of the B-cell receptor in tumor cells, including receptor revision, which occurs most likely in response to antigenic stimuli. N-glycosylation sites, commonly introduced in the V regions of tumors of the GC by somatic mutation, were not observed in the VH or in the VL functional genes, to support the concept that tumor events occur outside the GC. These data confirm heterogeneity in the cell of origin in terms of mutational status, with a minor subset with unmutated V-genes. Restricted V-gene segment usage, low levels of ongoing mutations with AID activated, and the new observation of receptor revision with re-expression of RAG enzymes indicate that selection by antigen could be a promoting factor in HCL development. Lack of novel glycosylation sites is in favour of interaction with antigenic stimuli occurring at extrafollicular sites.
15
Chapman, CJ, JX Zhou, C. Gregory, AB Rickinson, and FK Stevenson. "VH and VL gene analysis in sporadic Burkitt's lymphoma shows somatic hypermutation, intraclonal heterogeneity, and a role for antigen selection." Blood 88, no. 9 (November 1, 1996): 3562–68. http://dx.doi.org/10.1182/blood.v88.9.3562.bloodjournal8893562.
Full textAbstract:
Tumor cell lines and one tumor biopsy from seven cases of Epstein-Barr virus (EBV) genome-negative sporadic Burkitt's lymphoma (BL) have been investigated for usage and mutational pattern of Ig variable region genes. The VH genes were derived from the VH 3 (one) and VH4 (six) families and both the IgM-positive (six) and the IgA-positive (one) were all mutated from their germline counterparts. The VL genes were derived from V kappa 1 (one), V kappa 3 (one), V lambda 1 (four), and V lambda 2 (one) families and were also somatically hypermutated. Biopsy material from one of the IgM-positive cases showed VH and VL sequences that matched the derived cell line, with additional intraclonal sequence heterogeneity, indicating that the tumor cells had undergone posttranformation somatic mutation. Mutational patterns in V(H) genes did not show a conventional role for antigen in selecting tumor cell sequences. In contrast, patterns in VL sequences were consistent with a role for antigen in five of seven cases. The pattern of extensive scattered somatic hypermutation and intraclonal variation is similar to that in VH sequences of EBV genome-positive endemic BL, although the degree of mutational activity is less. These common features indicate that B cells involved in the two variants of BL may share a common clonal history.
16
Deng, Qu, and Dean G. Tang. "Androgen receptor and prostate cancer stem cells: biological mechanisms and clinical implications." Endocrine-Related Cancer 22, no. 6 (August 18, 2015): T209—T220. http://dx.doi.org/10.1530/erc-15-0217.
Full textAbstract:
Prostate cancer (PCa) contains phenotypically and functionally distinct cells, and this cellular heterogeneity poses clinical challenges as the distinct cell types likely respond differently to various therapies. Clonal evolution, driven by genetic instability, and intraclonal cancer cell diversification, driven by cancer stem cells (CSCs), together create tumor cell heterogeneity. In this review, we first discuss PCa stem cells (PCSCs) and heterogeneity of androgen receptor (AR) expression in primary, metastatic, and treatment-failed PCa. Based on literature reports and our own studies, we hypothesize that, whereas PCSCs in primary and untreated tumors and models are mainly AR−, PCSCs in CRPCs could be either AR+or AR−/lo. We illustrate the potential mechanisms AR+and AR−PCSCs may employ to propagate PCa at the population level, mediate therapy resistance, and metastasize. As a result, targeting AR alone may not achieve long-lasting therapeutic efficacy. Elucidating the roles of AR and PCSCs should provide important clues to designing novel personalized combinatorial therapeutic protocols targeting both AR+and AR−PCa cells.
17
Tarín, Fabián, Francisco López-Castaño, Carmen García-Hernández, Paola Beneit, Héctor Sarmiento, Pablo Manresa, Olga Alda, et al. "Multiparameter Flow Cytometry Identification of Neoplastic Subclones: A New Biomarker in Monoclonal Gammopathy of Undetermined Significance and Multiple Myeloma." Acta Haematologica 141, no. 1 (November 14, 2018): 1–6. http://dx.doi.org/10.1159/000493568.
Full textAbstract:
Multiparameter flow cytometry (MFC)-based clonality assessment is a powerful method of diagnosis and follow-up in monoclonal gammopathy of undetermined significance (MGUS) and multiple myeloma (MM). However, the relevance of intraclonal heterogeneity in immunophenotypic studies remains poorly understood. The main objective of this work was to characterize the different immunophenotypic subclones in MGUS and MM patients and to investigate their correlation with disease stages. An 8-color MFC protocol with 17 markers was used to identify the subclones within the neoplastic compartment of 56 MGUS subjects, 151 newly diagnosed MM patients, 30 MM subjects in complete remission with detectable minimal residual disease, and 36 relapsed/refractory MM patients. Two or more clusters were observed in > 85% of MGUS subjects, 75% of stage I MM patients, and < 15% in stage III. Likewise, a significant correlation between the dominant subclone size, secondary cytogenetic features, and changes in the expression of CD27, CD44, and CD81 was detected. The loss of intraclonal equilibrium may be an important factor related with kinetics and risk of progression not well considered to date in MFC studies. The MFC strategy used in this work can provide useful biomarkers in MGUS and MM.
18
Kriangkum, Jitra, Brian J. Taylor, Erin Strachan, Michael J. Mant, Tony Reiman, Andrew R. Belch, and Linda M. Pilarski. "Impaired class switch recombination (CSR) in Waldenström macroglobulinemia (WM) despite apparently normal CSR machinery." Blood 107, no. 7 (April 1, 2006): 2920–27. http://dx.doi.org/10.1182/blood-2005-09-3613.
Full textAbstract:
AbstractAnalysis of clonotypic isotype class switching (CSR) in Waldenström macroglobulinemia (WM) and IgM monoclonal gammopathy of undetermined significance (MGUS) reveals a normal initial phase of B-cell activation as determined by constitutive and inducible expression of activation-induced cytidine deaminase (AID). Switch μ (Sμ) analysis shows that large deletions are not common in WM or IgM MGUS. In CD40L/IL-4-stimulated WM cultures from 2 patients, we observed clonotypic IgG exhibiting intraclonal homogeneity associated with multiple hybrid Sμ/Sγ junctions. This suggests CSR had occurred within WM cells. Nevertheless, the estimated IgG/IgM-cell frequency was relatively low (1/1600 cells). Thus, for the majority of WM B cells, CSR does not occur even when stimulated in vitro, suggesting that the WM cell is constitutively unable to or being prevented from carrying out CSR. In contrast to WM, the majority of IgM MGUS clones exhibit intraclonal heterogeneity of IgH VDJ. Furthermore, most IgM MGUS accumulate more mutations in the upstream Sμ region than do WM, making them unlikely WM progenitors. These observations suggest that switch sequence analysis may identify the subset of patients with IgM MGUS who are at risk of progression to WM.
19
Bochtler, Tilmann, Maximilian Merz, Thomas Hielscher, Martin Granzow, Korbinian Hoffmann, Alwin Krämer, Marc-Steffen Raab, et al. "Cytogenetic intraclonal heterogeneity of plasma cell dyscrasia in AL amyloidosis as compared with multiple myeloma." Blood Advances 2, no. 20 (October 16, 2018): 2607–18. http://dx.doi.org/10.1182/bloodadvances.2018023200.
Full textAbstract:
Abstract Analysis of intraclonal heterogeneity has yielded insights into the clonal evolution of hematologic malignancies. We compared the clonal and subclonal compositions of the underlying plasma cell dyscrasia in 544 systemic light chain amyloidosis (PC-AL) patients with 519 patients with monoclonal gammopathy of undetermined significance (MGUS), smoldering multiple myeloma (SMM), or symptomatic MM; ie, PC–non-AL patients). Using interphase fluorescence in situ hybridization, subclones were stringently defined as clone size below two thirds of the largest clone and an absolute difference of ≥30%. Subclones were found less frequently in the PC-AL group, at 199 (36.6%) of 544 as compared with 267 (51.4%) of 519 in the PC–non-AL group (P < .001), and were not associated with the stage of plasma cell dyscrasia in either entity. In both groups, translocation t(11;14), other immunoglobulin heavy chain translocations, and hyperdiploidy were typically found as main clones, whereas gain of 1q21 and deletions of 8p21, 13q14, and 17p13 were frequently found as subclones. There were no shifts in the subclone/main clone ratio depending on the MGUS, SMM, or MM stage of plasma cell dyscrasia. In multivariate analysis, t(11;14) was associated with lower rates of subclone formation and hyperdiploidy with higher rates. PC-AL itself lost statistical significance, demonstrating that the lower subclone frequency in AL is a reflection of its exceptionally high t(11;14) frequency. In summary, the subclone patterns in PC-AL and PC–non-AL are closely related, implying that subclone formation depends on the main cytogenetic categories and is independent of disease entity and stage.
20
Brioli, Annamaria, Hannah Giles, Charlotte Pawlyn, John P. Campbell, Martin F. Kaiser, Lorenzo Melchor, Graham H. Jackson, et al. "Serum free immunoglobulin light chain evaluation as a marker of impact from intraclonal heterogeneity on myeloma outcome." Blood 123, no. 22 (May 29, 2014): 3414–19. http://dx.doi.org/10.1182/blood-2013-12-542662.
Full textAbstract:
Key Points The type of antibody secreted at relapse can serve as a marker of clonal heterogeneity. It is important to monitor for serum FLC in the suspicion of clinical relapse to ensure that FLC relapse is not missed.
21
Farges, Cédric, Murielle Roussel, Anne Huynh, Antoine Blancher, and Bénédicte Puissant-Lubrano. "Aggressive FLC Escape in a Patient with IgD Myeloma." Case Reports in Hematology 2015 (2015): 1–4. http://dx.doi.org/10.1155/2015/694730.
Full textAbstract:
Background. Some patients who are stable or in remission from a myeloma secreting intact monoclonal immunoglobulin (+/− associated free light-chains (FLCs)) relapse with production of FLC. This FLC escape is one of the illustrations of the intraclonal heterogeneity of multiple myeloma.Results. We report FLC escape in a patient with IgD myeloma characterized by a severe outcome. We discuss parameters that negatively impacted prognosis in this patient, including bone lesions, biochemical parameters, and genomic abnormalities.Conclusion. This case illustrates the selective pressure exerted by therapeutic drugs and the variable sensitivity of subclones to these drugs; it also highlights the importance of FLC monitoring in treated MM patients.
22
Walker, Brian A., Christopher P. Wardell, Lorenzo Melchor, Sanna Hulkki, Nicola E. Potter, David C. Johnson, Kerry Fenwick, et al. "Intraclonal heterogeneity and distinct molecular mechanisms characterize the development of t(4;14) and t(11;14) myeloma." Blood 120, no. 5 (August 2, 2012): 1077–86. http://dx.doi.org/10.1182/blood-2012-03-412981.
Full textAbstract:
Abstract We have used whole exome sequencing to compare a group of presentation t(4;14) with t(11;14) cases of myeloma to define the mutational landscape. Each case was characterized by a median of 24.5 exonic nonsynonymous single-nucleotide variations, and there was a consistently higher number of mutations in the t(4;14) group, but this number did not reach statistical significance. We show that the transition and transversion rates in the 2 subgroups are similar, suggesting that there was no specific mechanism leading to mutation differentiating the 2 groups. Only 3% of mutations were seen in both groups, and recurrently mutated genes include NRAS, KRAS, BRAF, and DIS3 as well as DNAH5, a member of the axonemal dynein family. The pattern of mutation in each group was distinct, with the t(4;14) group being characterized by deregulation of chromatin organization, actin filament, and microfilament movement. Recurrent RAS pathway mutations identified subclonal heterogeneity at a mutational level in both groups, with mutations being present as either dominant or minor subclones. The presence of subclonal diversity was confirmed at a single-cell level using other tumor-acquired mutations. These results are consistent with a distinct molecular pathogenesis underlying each subgroup and have important impacts on targeted treatment strategies. The Medical Research Council Myeloma IX trial is registered under ISRCTN68454111.
23
Rudders, R. A., D. L. Jespersen, J. Zacks, A. Sikorski, R. A. DeLellis, and T. Krontiris. "Clonal diversity in human B cell lymphoma. I. Idiotypic and genetic analysis of lymphoma heterohybrids." Journal of Immunology 144, no. 1 (January 1, 1990): 396–407. http://dx.doi.org/10.4049/jimmunol.144.1.396.
Full textAbstract:
Abstract Secretory heterohybrid clones from seven pristine human B cell lymphomas of diverse histologic types were established to investigate the question of tumor clonal diversity. We found that in six tumors, heterohybrid-derived Ig showed similar band patterns in IEF; families of anti-Id prepared from tumor Ig reacted uniformly with individual heterohybrids and original tumor; and the V gene loci displayed little variation on Southern analysis. In one patient who was followed with serial multiple site biopsies over a 14-mo period, clonal Id was preserved until the final stage of his disease, in spite of cytotoxic treatment. In a single follicular tumor (J.M.), each of the anti-Id reacted uniformly with the parent tumor and the individual heterohybrids, except that three of six clones failed to react with a single anti-Id family member. A Southern analysis of the VH gene locus revealed an identical gene rearrangement that was shared by the parent tumor and each heterohybrid. However, there was considerable heterogeneity of J.M. heterohybrid Ig in IEF gels, and we demonstrated the production of variant lambda L chains by the heterohybrid clones. One type of lambda L chain had a normal mobility in SDS-PAGE gels but larger lambda variants were produced by four of six heterohybrids. A Southern analysis of the VL gene displayed considerable variation in the type of lambda rearrangement present in the various heterohybrids, suggesting extensive diversity at the VL gene locus. In a second tumor (S.C.) that exhibited uniform anti-Id tumor reactivity we were also able to demonstrate the presence of a second minor tumor cell population (a biclonal tumor). Our data suggest that intraclonal VH variation may vary considerably with lymphoma subtype and mutagenic exposure and that an additional mechanism for generating spontaneous intraclonal heterogeneity is genetic variation at the VL locus.
24
Ballantyne, A. "Serum-free immunoglobulin light chain evaluation as a marker of impact from intraclonal heterogeneity on myeloma outcome." Annals of Clinical Biochemistry: An international journal of biochemistry and laboratory medicine 51, no. 6 (October 20, 2014): 718. http://dx.doi.org/10.1177/0004563214552219.
Full text
25
Malumbres, R., J. Davis, P. Ruiz, and I. S. Lossos. "Somatically mutated immunoglobulin VH genes without intraclonal heterogeneity indicate a post germinal center origin of primary intraocular diffuse large B-cell lymphomas." Journal of Clinical Oncology 25, no. 18_suppl (June 20, 2007): 8072. http://dx.doi.org/10.1200/jco.2007.25.18_suppl.8072.
Full textAbstract:
8072 Background: Primary intraocular lymphoma (PIOL) is a very rare high grade malignant non-Hodgkin lymphoma, usually of the diffuse large B cell lymphoma (DLBCL) type, which presents in the vitreous, retina and/or the optic nerve. Sixty to 80% of patients with PIOL eventually disseminate to the brain, whereas up to 15% of primary central nervous system lymphoma (PCNSL) patients exhibit ocular involvement. For these reasons, PIOL is regarded as a subtype of PCNSL. Analysis of the immunoglobulin heavy chain (VH) sequences in PCNSL tumors demonstrated biased overrepresentation of the VH4–34 gene and indicated derivation of these tumors from highly mutated germinal center (GC) B cells with ongoing mutational activity. Whether PIOL tumors are of similar or different origin is presently unknown. Methods: Immunoglobulin VH genes were examined in vitrectomy specimens of 4 PIOL patients, 1 patient with concomitant PCNSL and 1 patient with systemic DLBCL involving the eye. The extracted DNA was amplified by PCR using VH family specific primers, cloned and sequenced. Results: Seven clonal VH rearrangements belonging to the VH4, VH3 and VH1 families were cloned from the analyzed cases. In concordance with previous reports, the lymphomatous eye infiltrate from the PCNSL patient revealed a mutated clonal VH4–34 gene with intraclonal heterogeneity -a manifestation of active ongoing mutational activity. All the PIOL clonal VH rearrangements also exhibited mutated sequences with homology to the germline sequences ranging between 76 to 95%. However, in contrast to PCNSL, 3 out of 4 PIOL cases exhibited no intraclonal heterogeneity while the remaining case demonstrated ongoing somatic mutations in one of the 2 clonal VH rearrangements detected in this tumor. Interestingly, the clinical course of this patient was highly unusual, since he exhibited systemic dissemination during follow-up. Conclusions: Analysis of VH gene sequences from PIOL tumors indicate a post- GC derivation and suggest that they belong to the activated B cell (ABC)-like subtype of DLBCL. This is in contrast to the GC-origin of closely related PCNSL. No significant financial relationships to disclose.
26
Rawstron, Andy C., Darren J. Newton, Ruth M. de Tute, Jane Shingles, Fiona L. Bennett, Paul A. S. Evans, Sheila J. M. O’Connor, Andrew S. Jack, and Peter Hillmen. "Differential Protein Expression in MBL and CLL: LAIR1 Is a Powerful Surface Marker for Identifying Cases with Adverse Cellular Features." Blood 112, no. 11 (November 16, 2008): 2076. http://dx.doi.org/10.1182/blood.v112.11.2076.2076.
Full textAbstract:
Abstract INTRODUCTION: CLL is a disorder with a wide variation in outcome. Patients with adverse cellular features are often refractory to treatment and have a short overall survival. Individuals with CLL-type MBL are unlikely to require treatment and in most cases will eventually die of an unrelated cause. Many factors that predict a poor outcome have been identified, including stage, IGHV mutation status, ZAP-70 expression, and deletions of chromosomes 17p (TP53) and/or 11q23 (ATM). Deletions and mutations in TP53 are generally not presenting features and appear to require clonal evolution. One hypothesis is that the degree of intraclonal variation in genes targeted by the somatic hypermutation machinery, e.g. IGHV and BCL6, may predict the potential for clonal evolution. We have previously tested 66 antigens for their capacity to differentiate proliferating CLL cells, resting CLL cells and normal B-cells and identified 30 potentially relevant markers, including common markers such as CD38 and less frequently used markers such as the Leukocyte-associated immunoglobulin-like receptor 1 (LAIR1). AIM: To compare the expression of relevant cell surface markers with the degree of intraclonal variation in the IGHV and BCL6 genes and to determine if these markers can be used to differentiate CLL-type MBL and CLL with or without adverse biological features. METHODS: The cell surface phenotype was assessed by 6-colour cytometry in 133 patients: 22 CLL with deletion 17p or 11q23, 69 CLL with no adverse prognostic chromosomal abnormalities, and 42 MBL. Surface phenotype was also compared with IGHV mutation status in a cohort of 29 CLL patients (16 ≤2% IGHV mutation, 13 >2% IGHV mutation). These antigens were also assessed using 4-colour flow cytometry in 20 cases (4 MBL, 16 CLL) and compared with IGHV & BCL6 mutation status and degree of intraclonal variation (defined as the proportion of mutations that were detected in a single clone only), and with ZAP-70 (AF488-1E7.2) expression. RESULTS: CLL cases with ≤2% IGHV mutation showed increased expression of CD38 (6.8 fold, p 0.02), CD49d (4.9-fold, P = 0.04), IgD (2.0-fold, P = 0.05), ZAP-70 (1.5-fold, P=0.04) and decreased expression of LAIR-1 (6.2-fold, P = 0.003) in comparison to CLL cases with >2% IGHV mutation. CLL cases with deletions of 17p and 11q23 showed decreased expression of CCR6 (1.7-fold, P = 0.0001), IgD (1.3-fold, P = 0.03) and LAIR-1 (7.1-fold, P<0.0001) in comparison to CLL cases without deletion 17p/11q23. CLL cases showed increased expression of CD23 (1.4-fold, P = 0.04), CD25 (1.3-fold, P = 0.05) and CD62L (1.7-fold, P = 0.04) in comparison to MBL. Cases with ≤2% overall IGHV mutation showed a similar degree of intraclonal variation as cases with >2% overall IGHV mutation in both IGHV (median 0.075% vs. 0.049% unique mutations, P>0.05) and BCL6 (median 0.10% vs. 0.095% unique mutations, P>0.05). However, there was an inverse relationship between BCL6 and IGHV intraclonal variation and cases with the highest levels of BCL6 intraclonal variation showed significantly decreased expression of CD39 (1.9-fold, P = 0.04) and LAIR1 (4.7-fold, P = 0.019). CONCLUSIONS: There were no markers or marker combinations that could discriminate MBL from CLL. The key differences were decreased expression of markers that are expressed during cell cycle, i.e. CD23, and adhesion markers such as CD62L and CD49d. These markers show sequential changes with disease stage, supporting the hypothesis that cellular interactions are central to the accumulation and expansion of CLL cells. However, the marker most consistently associated with adverse biological features is LAIR1, which is weak or negative in CLL with ≤2% IGHV mutation, high levels of intraclonal variation and TP53 or ATM deletions. LAIR-1 is an inhibitory receptor involved in regulating classs-witching. LAIR1 is strongly expressed in normal circulating peripheral B-cells. As with other prognostic markers, expression is a continuous variable and therefore a suitable cutoff will need to be identified. However, fluorochrome-conjugated antibodies are readily available and expression on CLL cells is stable for several days in EDTA samples which should minimise inter-laboratory analytical variation. LAIR1 expression in CLL is more closely associated with IGHV mutation status than CD38 or ZAP-70 expression. LAIR1 is a promising prognostic marker that appears to be central to the development of aggressive CLL as there is a strong association between downregulation of LAIR1, intraclonal heterogeneity in BCL6 and development of TP53 and ATM deletions.
27
Lafarge, Xavier, Vincent Pitard, Sophie Ravet, David Roumanes, Franck Halary, Claire Dromer, Eric Vivier, Pascale Paul, Jean-François Moreau, and Julie Déchanet-Merville. "Expression of MHC class I receptors confers functional intraclonal heterogeneity to a reactive expansion of γδ T cells." European Journal of Immunology 35, no. 6 (June 2005): 1896–905. http://dx.doi.org/10.1002/eji.200425837.
Full text
28
Arendt, Bonnie K., Raphael Fonseca, Gregory Ahmann, and Diane F. Jelinek. "Analysis of Intratumor Heterogeneity in Multiple Myeloma Using Methylcellulose Clonogenic Assays." Blood 104, no. 11 (November 16, 2004): 2346. http://dx.doi.org/10.1182/blood.v104.11.2346.2346.
Full textAbstract:
Abstract Multiple myeloma (MM) is a fatal disease characterized by the accumulation of malignant plasma cells in the bone marrow. Although progress has been made in better understanding growth control of this disease, effective treatment of MM patients with this disease is likely complicated by the extensive patient to patient variability that exists, as well variability within the tumor population itself. Thus, there is abundant evidence that intraclonal or intratumor heterogeneity exists in myeloma as revealed by morphologic and phenotypic heterogeneity in primary myeloma cells isolated from a single patient. We have had a long-standing interest in the growth regulation of myeloma cells and have hypothesized, along with other investigators, that there may only be a subset of myeloma cells that exhibits extensive proliferative potential. Understanding how cellular compartments within the malignant clone, as defined by identical immunoglobulin variable region sequence, may vary in growth regulation properties in isolation or in the company of less proliferative tumor cell subsets is key to understanding disease progression and how to better target the putative proliferative subset in myeloma. In this study, we have used a methylcellulose clonogenic assay to study intraclonal heterogeneity in a panel of human MM cell lines. Each of these cell lines, DP-6, KAS-6/1, KP-6, and, exhibit a variable response to IL-6 and IGF-I, and our goal was to evaluate growth responsiveness of individual subclones from each of these cell lines. Myeloma cell lines were plated at a concentration of 200-1000 cells in 1 ml Methocult H4533 in 35 mm gridded dishes with or without various cytokines. Following 3 weeks of culture, colonies were scored and those consisting of >40 cells were isolated, expanded, and studied further. Of interest, subclones isolated from each of the cell lines displayed significant differences in growth response to various cytokines in addition to specific morphologic and phenotypic differences. In this regard, results emerging from the DP-6 cell line were particularly intriguing. We have previously shown that the DP-6 cell line displays a proliferative response to both IL-6 and IGF-I and expresses autocrine IL-6 at a low level. Analysis of the growth properties of individual DP-6 clones revealed the existence of DP-6 cells (clone 1-15) that proliferate at a rapid rate in the apparent absence of exogenous growth factors. Whereas a neutralizing antibody to IL-6 did not inhibit cell growth, addition of a blocking antibody to the IGF-IR, (αIR3), completely blocked growth factor independent proliferation. Phenotypic analysis also displayed variation between the parental cell line and its subclone. For instance, the parental DP-6 cells largely expressed CD45 at a high level, whereas the clone 1-15 did not. Finally, we have also further characterized MM cell line subclones by gene profiling and FISH (fluorescence in situ hybridization) analysis to link specific phenotype and genotypes with patterns of cell growth. These results provide additional evidence that intratumor heterogeneity exists in myeloma. These studies further demonstrate how growth regulation may vary considerably among cellular subsets of the malignant population. Understanding what factors regulate the balance of specific myeloma cell subpopulations is key to an understanding of tumor progression. In summary, these studies provide a necessary foundation for future studies of the growth potential of subsets found in primary MGUS, SMM and MM patient samples.
29
Chapman, CJ, CI Mockridge, M. Rowe, AB Rickinson, and FK Stevenson. "Analysis of VH genes used by neoplastic B cells in endemic Burkitt's lymphoma shows somatic hypermutation and intraclonal heterogeneity." Blood 85, no. 8 (April 15, 1995): 2176–81. http://dx.doi.org/10.1182/blood.v85.8.2176.bloodjournal8582176.
Full textAbstract:
Tumor cell lines from six typical cases of endemic Epstein-Barr virus (EBV) genome-positive Burkitt's lymphoma (BL) have been investigated for usage and mutational pattern of Ig VH genes. The neoplastic cells all had a t(8;14) (q24;q32) translocation involving the c-myc protooncogene. The VH genes were derived from VH1, VH3 and VH4, and both the IgM-positive (four cases) and IgG-positive (two cases) were extensively mutated from germline sequence. In two cases, early and late passage tumor cells were available, and the VH nucleotide sequences were identical, indicating that mutations had not accumulated in vitro. In a further case, there was evidence of sequence heterogeneity, which appeared to have been generated in vivo, indicating that the tumor cell VH gene was able to undergo posttranslocation somatic hypermutation. Analysis of the relatively nonpolymorphic VH4 genes for the pattern of replacement or silent mutations did not show a role for antigen selection in the expressed sequences.
30
Walker, B. A., C. P. Wardell, L. Melchor, A. Brioli, D. C. Johnson, M. F. Kaiser, F. Mirabella, et al. "Intraclonal heterogeneity is a critical early event in the development of myeloma and precedes the development of clinical symptoms." Leukemia 28, no. 2 (July 2, 2013): 384–90. http://dx.doi.org/10.1038/leu.2013.199.
Full text
31
Kraj, Maria, Barbara Kruk, Kelly Endean, Krzysztof Warzocha, Katarzyna Budziszewska, and Monika Dąbrowska. "Light Chain Escape in 3 Cases: Evidence of Intraclonal Heterogeneity in Multiple Myeloma from a Single Institution in Poland." Case Reports in Hematology 2015 (2015): 1–5. http://dx.doi.org/10.1155/2015/809840.
Full textAbstract:
We report three cases of light chain escape (LCE) at a single institution in Poland, including an interesting case of biclonal monoclonal gammopathy of undetermined significance (MGUS) that satisfied the criteria for progression to light chain multiple myeloma (LCMM) with a rapid rise in serum free light chain (FLC) levels, following steroidal treatment for simultaneous temporal artery inflammation and polymyalgia rheumatica (PMR). In the three cases discussed, progression of the disease by light chain escape was associated with rapid and severe renal impairment, highlighting the necessity for prompt detection of such free light chain-only producing clones in order to prevent the possible development of irreversible end-organ damage. Interestingly, monitoring of these three patients by serum free light chain assay (sFLC) and retrospective heavy/light chain analysis (HLC) detected this clonal evolution prior to clinical relapse and suggests that these assays represent important additional tools for more accurate monitoring of multiple myeloma patients.
32
Zehentner, Barbara K., Monica E. de Baca, Denise A. Wells, and Michael R. Loken. "Intraclonal Heterogeneity in Concomitant Monoclonal Lymphocyte and Plasma Cell Populations: Combining Flow Cytometric Cell Sorting With Molecular Monoclonality Profiling." Clinical Lymphoma Myeloma and Leukemia 13, no. 2 (April 2013): 214–17. http://dx.doi.org/10.1016/j.clml.2013.02.004.
Full text
33
Schettino, Edward W., Andrea Cerutti, Nicholas Chiorazzi, and Paolo Casali. "Lack of Intraclonal Diversification in Ig Heavy and Light Chain V Region Genes Expressed by CD5+IgM+ Chronic Lymphocytic Leukemia B Cells: A Multiple Time Point Analysis." Journal of Immunology 160, no. 2 (January 15, 1998): 820–30. http://dx.doi.org/10.4049/jimmunol.160.2.820.
Full textAbstract:
Abstract To analyze the modalities of clonal expansion of chronic lymphocytic leukemia (CLL) cells, we sequenced at multiple time points the V(D)J genes expressed by CD5+IgM+CLL B cells in three patients. All three V(D)J gene sequences were found to be point mutated. The mutation frequency in the Ig VH (3.96 × 10−2 and 2.41 × 10−2 change/bp) and Vκ and Vλ (6.67 × 10−2 and 1.74 × 10−2 change/bp) genes of two CLLs (1.19 and 1.32, respectively) was similar, and higher than that in the corresponding gene segments of the third CLL (1.69; 3.4 × 10−3 and 6.67 × 10−3 change/bp). In all three CLLs, there was no preferential representation of nucleotide changes yielding amino acid replacement (R mutations), nor was there any preferential segregation of R mutations within the Ig V gene complementarity-determining regions. In all three CLLs, the somatic mutations were all identical in multiple Ig VHDJH transcripts at any given time point, and were all conserved at multiple time points throughout a 2-yr period. The lack of concentration of R mutations in the complementarity-determining regions and the lack of intraclonal heterogeneity suggest that Ag may no longer be able to play a significant role in the clonal expansion of these cells. This conclusion would be strengthened further by the germline configuration of the bcl-1 and bcl-2 proto-oncogenes that are translocated in neoplastic B cells that display significant traces of intraclonal diversification and Ag-dependent selection, such as B-prolymphocytic leukemia and low grade follicular non-Hodgkin lymphoma.
34
Isa, Reiko, Mano Horinaka, Taku Tsukamoto, Kentaro Mizuhara, Yuto Fujibayashi, Yoko Taminishi-Katsuragawa, Haruya Okamoto, et al. "The Rationale for the Dual-Targeting Therapy for RSK2 and AKT in Multiple Myeloma." International Journal of Molecular Sciences 23, no. 6 (March 8, 2022): 2919. http://dx.doi.org/10.3390/ijms23062919.
Full textAbstract:
Multiple myeloma (MM) is characterized by remarkable cytogenetic/molecular heterogeneity among patients and intraclonal diversity even in a single patient. We previously demonstrated that PDPK1, the master kinase of series of AGC kinases, is universally active in MM, and plays pivotal roles in cell proliferation and cell survival of myeloma cells regardless of the profiles of cytogenetic and genetic abnormalities. This study investigated the therapeutic efficacy and mechanism of action of dual blockade of two major PDPK1 substrates, RSK2 and AKT, in MM. The combinatory treatment of BI-D1870, an inhibitor for N-terminal kinase domain (NTKD) of RSK2, and ipatasertib, an inhibitor for AKT, showed the additive to synergistic anti-tumor effect on human MM-derived cell lines (HMCLs) with active RSK2-NTKD and AKT, by enhancing apoptotic induction with BIM and BID activation. Moreover, the dual blockade of RSK2 and AKT exerted robust molecular effects on critical gene sets associated with myeloma pathophysiologies, such as those with MYC, mTOR, STK33, ribosomal biogenesis, or cell-extrinsic stimuli of soluble factors, in HMCLs. These results provide the biological and molecular rationales for the dual-targeting strategy for RSK2 and AKT, which may overcome the therapeutic difficulty due to cytogenetic/molecular heterogeneity in MM.
35
Malumbres, Raquel, Janet Davis, Phillip Ruiz, and Izidore S. Lossos. "Somatically mutated immunoglobulinIGHV@genes without intraclonal heterogeneity indicate a postgerminal centre origin of primary intraocular diffuse large B-cell lymphomas." British Journal of Haematology 138, no. 6 (September 2007): 749–55. http://dx.doi.org/10.1111/j.1365-2141.2007.06744.x.
Full text
36
Martin, Patricia, Annie Dary, Axelle André, Gilles Fischer, Pierre Leblond, and Bernard Decaris. "Intraclonal polymorphism in the bacterium Streptomyces ambofaciens ATCC23877: evidence for a high degree of heterogeneity of the wild type clones." Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis 430, no. 1 (November 1999): 75–85. http://dx.doi.org/10.1016/s0027-5107(99)00149-9.
Full text
37
Zhu, Delin, Jennifer Orchard, David G. Oscier, Dennis H. Wright, and Freda K. Stevenson. "V H gene analysis of splenic marginal zone lymphomas reveals diversity in mutational status and initiation of somatic mutation in vivo." Blood 100, no. 7 (October 1, 2002): 2659–61. http://dx.doi.org/10.1182/blood-2002-01-0169.
Full textAbstract:
Tumors of the splenic marginal zone can present in spleen or blood. The maturational status of the neoplastic B cells from each site appears heterogeneous, with either unmutated or mutated variable-region heavy chain (VH) genes. To determine an influence of tissue location, we assessed matched blood and splenic tumor cells from 4 patients and found them identical. However, one patient with unmutated VH genes in blood and spleen developed a clonally related diffuse large B-cell lymphoma in the chest wall. Strikingly, this subclone had undergone significant somatic mutation, with clear intraclonal heterogeneity. To our knowledge, this is the first case of a B-cell tumor showing initiation of somatic mutation in vivo. The finding emphasizes that the tissue microenvironment can influence tumor cell behavior and possibly affect disease progression. Importantly, because several replacement mutations were located within or close to the complementarity-determining regions (CDRs), it raises the question of a role for antigen in driving tumor growth.
38
Ciric, Bogoljub, Virginia VanKeulen, Moses Rodriguez, Robert A. Kyle, Morie A. Gertz, and Larry R. Pease. "Clonal evolution in Waldenstrom macroglobulinemia highlights functional role of B-cell receptor." Blood 97, no. 1 (January 1, 2001): 321–23. http://dx.doi.org/10.1182/blood.v97.1.321.
Full textAbstract:
Abstract The course of clonal evolution of 2 related clones in the blood of a patient with Waldenstrom macroglobulinemia (WM) indicates the functional importance for the expression of the B-cell receptor for the survival of these malignant cells. Protein and nucleotide sequencing of the paraproteins' variable regions revealed 2 predominant Vλ and 2 VH sequences, each set comprised in the ratio 1:1.5. The 2 VH sequences and 2 Vλ sequences shared the same VDJ and VJ junctional sequences, respectively, indicating that 2 malignant clones had evolved from a common ancestor. This is the first report on intraclonal heterogeneity in WM. Comparison of the Vλ and VH sequences with the closest matching known germline genes showed that they contained approximately 10 somatic mutations each. The distribution and type of mutations demonstrate that mutations have continued to accumulate in the malignant clones and that selection has been operating to preserve immunoglobulin structure.
39
Tschumper, Renee C., Yan W. Asmann, Asif Hossain, Paul M. Huddleston, Xiaosheng Wu, Angela Dispenzieri, Bruce W. Eckloff, and Diane F. Jelinek. "Assessment of Multiple Myeloma IGHV Intraclonal Variation by Massively Parallel Pyrosequencing." Blood 118, no. 21 (November 18, 2011): 1814. http://dx.doi.org/10.1182/blood.v118.21.1814.1814.
Full textAbstract:
Abstract Abstract 1814 Multiple myeloma (MM) is an incurable hematologic disorder characterized by the accumulation of plasma cells (PCs) in the bone marrow (BM). Like normal B cells and PCs, MM cells express a distinctive immunoglobulin (Ig) molecular fingerprint resulting from heavy and light chain gene rearrangements and unique mutations introduced by the somatic hypermutation (SHM) process. Detailed examination of the Ig molecule may offer insight into the etiology of B cell malignancies as well as the ontogeny of malignant transformation and ongoing genetic evolution. Because prior studies of the Ig fingerprint of MM cells have been limited in size and scope, our current understanding of MM Ig repertoire is minimal. We used massively parallel sequencing of normal and malignant PCs to interrogate: 1) DNA versus RNA (cDNA) as starting material for studies of Ig repertoire; 2) the Ig repertoire of normal and malignant PCs; and 3) intraclonal heterogeneity in MM. Bone marrow PCs (BMPCs) from an untreated MM patient and from a normal control subject were isolated by magnetic bead separation. DNA and RNA were isolated from purified cells and amplified in a multiplex PCR reaction with primers designed to capture the entire IGHV region including the heavy chain complementarity determining region 3 (HCDR3) necessary for defining clonal cells. Using Roche 454 GS-FLX Titanium chemistry and a GS FLX Titanium Genome Sequencer, over 30,000 sequence reads were obtained from each sample. Following a detailed algorithm to minimize Taq and sequencing related errors and removal of non-Ig or non-productive Ig sequences, the resulting sequences were grouped based on HCDR3 amino acid identity. Each unique HCDR3 represented one member of the repertoire and all the sequences with the same HCDR3 defined the clone size. This measurement showed that there was nearly a five-fold higher level of unique HCDR3s in normal BMPCs when the starting PCR template was DNA vs. cDNA. Thus, DNA is clearly a better starting template for repertoire analysis using deep sequencing methods. Thorough analysis of the MM DNA sample identified PCs expressing 37 different IGHV genes, and predictably, the vast majority of sequence reads (83%) had exact nucleotide identity in the IGHV and HCDR3 region (IGHV3-74 with 18 mutations in the IGHV region) thereby defining the dominant MM clone. There were also ∼5000 additional sequences that either shared an identical HCDR3 region but varied within the IGHV3-74 gene sequence (n=3975) or were identical within the IGHV3-74 sequence yet varied within the HCDR3 (n=862). These sequences were further analyzed, with sequences not present 10 or more times or not found in both the 5' and 3' directions eliminated from further scrutiny. This process revealed a total of 64 putative subclones with single point mutations in the IGHV or HCDR3 region (10–56 copies of each unique sequence representing a total of 1583 clonally related sequences). When we used a more stringent subclone frequency of ≥0.1%, 22 subclones remained. Of note, conventional Ig repertoire analysis would require sequencing ≥1000 colonies to detect MM subclones present at this frequency. Finally, 11 subclones displayed a significant number of IGHV gene nucleotide differences from the dominant MM clone despite exhibiting an identical HCDR3 region. Notably, a number of these distinguishing IGHV gene mutations are silent and thus may preserve the antigenic specificity of these clonally related cells. These subclones failed our frequency criteria but the type and quality of deviations from the clonal sequence suggest that they are not artifact and warrant further investigation. Notably, all of the putative subclones were also found in the MM cDNA cohort providing further evidence as genuine subclones. The very large number of identical MM clonal sequences is consistent with the idea that MM is a post germinal center malignancy that can no longer undergo SHM. However, we present clear evidence of MM-related subclones albeit relatively small in number. The subclone sequence deviations discovered may reflect on-going genetic evolution independent of the formal SHM mechanism. Alternatively, these subclones may indeed reflect “sister” cells generated during the original germinal center reaction that resulted in the malignant clone. In summary, our studies demonstrate the extraordinary potential of this methodology to track clonal evolution in MM and its precursor conditions over time. Disclosures: No relevant conflicts of interest to declare.
40
Cremer, Friedrich W., Mutlu Kartal, Dirk Hose, Jelena Bila, Isabelle Buck, Frauke Bellos, Marc-Steffen Raab, et al. "High incidence and intraclonal heterogeneity of chromosome 11 aberrations in patients with newly diagnosed multiple myeloma detected by multiprobe interphase FISH." Cancer Genetics and Cytogenetics 161, no. 2 (September 2005): 116–24. http://dx.doi.org/10.1016/j.cancergencyto.2005.02.015.
Full text
41
Burack, Richard, Hongli Li, Diana G. Adlowitz, Janice M. Spence, Michael L. Leblanc, Lisa M. Rimsza, Rita M. Braziel, et al. "Intraclonal Heterogeneity Caused By Activation-Induced Cytidine Deaminase Is Not a Prognostic Biomarker in Untreated Advanced Stage Follicular Lymphoma: An Analysis of SWOG S0016." Blood 134, Supplement_1 (November 13, 2019): 2771. http://dx.doi.org/10.1182/blood-2019-121632.
Full textAbstract:
Background: Activation induced cytidine deaminase (AICDA or AID) causes somatic hypermutation (SHM) of the immunoglobulin heavy chain variable genes (IGHV). It has been widely hypothesized that aberrant targeting of AICDA creates additional driver mutations and intra-clonal heterogeneity which enables clonal evolution and thus disease progression. This hypothesis predicts that greater AICDA-mediated intraclonal heterogeneity will be associated with shortened progression free survival (PFS). To definitively test this hypothesis that AICDA-mediated heterogeneity is linked to risk of progression, we evaluated available samples from the largest US-based phase 3 trial of untreated follicular lymphoma patients treated with CHOP-based therapies, SWOG trial S0016. Methods: We have previously shown that ultradeep sequencing of two genes, the expressed IGHV and the 5' UTR of the translocated BCL2 allele, provide unrelated measures of AICDA-mediated genetic heterogeneity (Spence, J Immunol. 2014). Furthermore, the number of AICDA-mediated mutations in the 5' UTR of BCL2, but not in IGHV, correlates with the number of AICDA-mediated mutations at other known AICDA sites throughout the genome (such as PIM1, BCL6, RHOA, etc). Genomic DNA was prepared from all available paraffin-embedded specimens. Ultra-deep, amplicon-based sequencing (~10,000x) with internal controls to establish specimen-specific signal-to-noise parameters allowed sensitive and specific detection of sequence variants at 0.2% (FDR 1%). Results: For subjects with (152) and without (419) available specimens, the median duration of follow-up (11.3 years), the number of patients who progressed (60%), and other patient characteristics (demographics, histology, stage, FLIPI) were indistinguishable. Sequencing data that fulfilled strict quality metrics for low frequency variants were obtained for >75% of the specimens (114 for BCL2; 120 for IGHV); further analysis was restricted to these subjects. The extent of intraclonal variation within both the IGHV and the 5' UTR of BCL2 was highly variable. For BCL2, a median of 7 mutations/case were detected (range 0-61); the mutations were highly skewed to the RCYW motif (p<0.001), the preferred target of AICDA. These mutations defined a median of 5 subclones/case (range 1-22). The clonal IGHV was somatically mutated (<0.98 germline identity) in 94% of samples (median 0.89). For IGHV, a median of 113 subclones/case were detected (range 0-1531). Consistent with our prior study, no correlation was seen between the number of mutations detected in the IGHV and BCL2 or the number of subclones defined by IGHV and BCL2. Neither the number of mutations in nor the number of subclones defined by BCL2 or IGHV were prognostic. Cox regression showed no relationship between PFS and mutation number or subclone count based on either IGHV or BCL2 (hazard ratios are indistinguishable from 1; parameters were treated both as a continuous variables and dichotomized as quartiles). Furthermore, receiver operator curves did not suggest a cut point for any of these measures that would predict disease progression at any time (areas under the curve are indistinguishable from 0.5). Conclusions: Several measures of AICDA-mediated mutation and resulting subclonal heterogeneity were not found to be prognostic in previously untreated, advanced stage FL treated with CHOP-based regimens. In contrast, AICDA-mediated mutations have been reported to accrue during transformation from low grade FL to large cell lymphoma. This paradox calls for a more refined model to explain the role of AICDA in the progression of FL. Support: NIH/NCI grants U10CA180888, U10CA180819, U10CA180821, R21CA198072(WRB); and in part by GlaxoSmithKline. Disclosures Rimsza: NanoSting: Patents & Royalties: Named inventor on a patent licensed to NanoSting [Institution]. Leonard:Bayer Corporation: Consultancy; AstraZeneca: Consultancy; Genentech, Inc./F. Hoffmann-La Roche Ltd: Consultancy; Sandoz: Consultancy; ADC Therapeutics: Consultancy; Miltenyi: Consultancy; BeiGene: Consultancy; Sutro Biopharma: Consultancy; Celgene: Consultancy; Nordic Nanovector: Consultancy; Gilead: Consultancy; Karyopharm Therapeutics: Consultancy; Genentech, Inc./F. Hoffmann-La Roche Ltd: Consultancy; Bayer Corporation: Consultancy; Celgene: Consultancy; Epizyme, Inc: Consultancy; Merck: Consultancy; MorphoSys: Consultancy; AstraZeneca: Consultancy; Epizyme, Inc: Consultancy; Akcea Therapeutics: Consultancy; Miltenyi: Consultancy; ADC Therapeutics: Consultancy; BeiGene: Consultancy; Karyopharm Therapeutics: Consultancy; Merck: Consultancy; Sandoz: Consultancy; Gilead: Consultancy; Akcea Therapeutics: Consultancy; MorphoSys: Consultancy; Nordic Nanovector: Consultancy; Sutro Biopharma: Consultancy. Fisher:Celgene: Consultancy; Barclays: Honoraria; AstraZeneca: Consultancy; prIME: Honoraria. Smith:Portola Pharmaceuticals: Research Funding. Friedberg:Bayer: Honoraria, Other: Data & Safety Monitoring Committee; Acerta: Other: Data & Safety Monitoring Committee.
42
Nish, Simone A., Kyra D. Zens, Radomir Kratchmarov, Wen-Hsuan W. Lin, William C. Adams, Yen-Hua Chen, Bonnie Yen, et al. "CD4+ T cell effector commitment coupled to self-renewal by asymmetric cell divisions." Journal of Experimental Medicine 214, no. 1 (December 6, 2016): 39–47. http://dx.doi.org/10.1084/jem.20161046.
Full textAbstract:
Upon infection, an activated CD4+ T cell produces terminally differentiated effector cells and renews itself for continued defense. In this study, we show that differentiation and self-renewal arise as opposing outcomes of sibling CD4+ T cells. After influenza challenge, antigen-specific cells underwent several divisions in draining lymph nodes (LN; DLNs) while maintaining expression of TCF1. After four or five divisions, some cells silenced, whereas some cells maintained TCF1 expression. TCF1-silenced cells were T helper 1–like effectors and concentrated in the lungs. Cells from earliest divisions were memory-like and concentrated in nondraining LN. TCF1-expressing cells from later divisions in the DLN could self-renew, clonally yielding a TCF1-silenced daughter cell as well as a sibling cell maintaining TCF1 expression. Some TCF1-expressing cells in DLNs acquired an alternative, follicular helper-like fate. Modeled differentiation experiments in vitro suggested that unequal PI3K/mechanistic target of rapamycin signaling drives intraclonal cell fate heterogeneity. Asymmetric division enables self-renewal to be coupled to production of differentiated CD4+ effector T cells during clonal selection.
43
Forconi, Francesco, Surinder S. Sahota, Donatella Raspadori, Micaela Ippoliti, Gavin Babbage, Francesco Lauria, and Freda K. Stevenson. "Hairy cell leukemia: at the crossroad of somatic mutation and isotype switch." Blood 104, no. 10 (November 15, 2004): 3312–17. http://dx.doi.org/10.1182/blood-2004-03-0950.
Full textAbstract:
Abstract Hairy cell leukemia (HCL) commonly expresses multiple immunoglobulin isotypes, a feature rare in other B-cell malignancies or in normal B cells. In HCL, there is no phenotypic evidence for subpopulations, and single cells from one previous case contained transcripts for several isotypes. This raises the questions of the differentiation status of the cell of origin and of posttransformation events. We have investigated 9 cases, all expressing multiple immunoglobulin isotypes. Multiple tumor-derived variable-(diversity)-joining-constant μ δ, γ, α (V(D)J-Cμ, δ, γ, α) transcripts were confirmed in single cells of a further case. All cases were negative for germinal center (GC)-associated markers CD27 and CD38. Seven of 9 cases had mutated VH genes, with low levels of intraclonal heterogeneity, but 2 of 9 were unmutated, indicative of pre-GC origin. Eight of 9 cases expressed activation-induced cytidine deaminase (AID), a molecule essential for somatic mutation and isotype switch. All cases expressed germ line heavy-chain I exon (IH)-CH transcripts which paralleled surface immunoglobulin (sIg) isotype. Significantly, no circle transcripts indicative of deletional recombination of switched isotypes were detectable in 9 of 9 cases. These data indicate heterogeneity in the cell of origin in terms of mutational status, but reveal common features of AID expression and isotype-switching events occurring prior to deletional recombination. Both mutational and switching events may be influenced by environmental factors at extrafollicular sites. (Blood. 2004;104:3312-3317)
44
Hui, M. F., P. Lam, and H. M. Dosch. "Properties and heterogeneity of human fetal pre-B cells transformed by EBV." Journal of Immunology 143, no. 8 (October 15, 1989): 2470–79. http://dx.doi.org/10.4049/jimmunol.143.8.2470.
Full textAbstract:
Abstract A series of 75 EBV-transformed pre-B and B-cell lines from fetal bone marrow at 14 to 18 wk of gestation was cloned for phenotypic, functional and molecular genetic studies. B-cell type volume regulation in response to hypotonic stress, low level CD9 (BA2), and, perhaps biased by our use of EBV, functional EBV receptors with expression of CD21 (B2) determinants characterized the most immature cells detected. These "B-progenitors" contained EBV genomes, maintained Ig H and L chain (as well as TCR) constant region genes in germ-line configuration and did not express other B, T, or myeloid lineage-associated surface markers including CD20 and MHC class II determinants. Such cells may represent B progenitor cells preceding classical pre-B-lymphocytes in pathways of B cell differentiation. Reminiscent of Abelson virus-induced transformation of immature murine B cells, EBV transformability together with the above properties may be the earliest markers of B lineage commitment in man. The expression of MHC class II Ag, CD20, C mu-H and then L chain rearrangements and expression followed in less immature pre-B lymphocytes and permitted a classification of lines into discrete subgroups of increasing maturity. The physical organization of the H chain locus in a given line was a stable characteristic. However, fetal pre-B cell lines showed considerable intraclonal heterogeneity with respect to H chain gene expression and that of differentiation markers such as CD20. Subcloning experiments indicated that this heterogeneity reflected clonally stable expression patterns distributed among subclones in an all-or-none fashion. The induction, by IL-6, of L chain expression in some but not all of these clones was linked to the presence of C mu transcription products, consistent with a possible regulatory role of mu protein in L chain rearrangement and expression. Although pre-B cell differentiation likely follows inherent programming, external signals seem able to hasten development along prescribed, hierarchical differentiation pathways.
45
Sennerstam, R. "Partition of protein (mass) to sister cell pairs at mitosis: a re-evaluation." Journal of Cell Science 90, no. 2 (June 1, 1988): 301–6. http://dx.doi.org/10.1242/jcs.90.2.301.
Full textAbstract:
Since the 1960s it has been thought that there is to some extent a difference in the partition of mass to daughter cells at mitosis. Recent studies using modern techniques give further support to such a phenomenon, which has become almost an axiom in cell biology. It has been suggested that such unequal distribution of metabolic constituents at mitosis contributes to the dispersion in cell generation times. In the present work, PCC3 embryonal carcinoma (EC) cells were studied as undifferentiated G1 sister pairs by microspectrophotometry (MSP) following Feulgen-Naphthol Yellow staining (FNYS), in order to evaluate their protein content. Despite the considerable intraclonal intermitotic time heterogeneity found in undifferentiated PCC3 EC cells, it was concluded thta the postmitotic difference in mass (protein) between sister cell pairs exerts a minimal influence upon the cell population mass variability, whereas it was deduced to have an influence upon variation in interphase time duration when comparing sister cell pairs. This offers a cell-physiological explanation to the randomly distributed difference repeatedly found between sister cell generation times. Furthermore, there was no correlation seen between the mass difference found between sister cell pairs postmitotically and the size of the mother cell.
46
Sahota, Surinder S., Richard Garand, Razeen Mahroof, Alastair Smith, Nadine Juge-Morineau, Freda K. Stevenson, and Regis Bataille. "VH Gene Analysis of IgM-Secreting Myeloma Indicates an Origin From a Memory Cell Undergoing Isotype Switch Events." Blood 94, no. 3 (August 1, 1999): 1070–76. http://dx.doi.org/10.1182/blood.v94.3.1070.415k25_1070_1076.
Full textAbstract:
IgM-secreting plasma cell tumors are rare variants of typical isotype-switched multiple myeloma with a similar disease outcome. To probe the origin and clonal history of these tumors, we have analyzed VH gene sequences in 6 cases. Potentially functional tumor-derived VH genes were all derived from VH3, with the V3-7 gene segment being used by 4 of 6. All were somatically mutated, with a mean deviation from germline sequence of 5.2% (range, 3.1% to 7.1%). The distribution of replacement mutations was consistent with antigen selection in 4 of 6 cases, and no intraclonal heterogeneity was observed. Clonally related switched isotype transcripts were sought in 4 cases, and Cγ transcripts with tumor-derived CDR3 sequence were identified in 2 of 4. These findings indicate that IgM-secreting myelomas are arrested at a postfollicular stage at which somatic mutation has been silenced. Isotype switch variants show the cell of origin to be at the IgM to IgG switch point. These features indicate that the final neoplastic event has occurred at a stage immediately before that of typical isotype-switched myeloma. One possibility is that IgM myeloma involves the previously identified precursor cell of typical myeloma.
47
Kalakonda, Nagesh, Dominic G. Rothwell, J. Howard Scarffe, and John D. Norton. "Detection of N-Ras codon 61 mutations in subpopulations of tumor cells in multiple myeloma at presentation." Blood 98, no. 5 (September 1, 2001): 1555–60. http://dx.doi.org/10.1182/blood.v98.5.1555.
Full textAbstract:
Activating point mutations in codons 12, 13, or 61 of the K-ras and N-ras genes have been reported to occur in up to 40% of patients with multiple myeloma at presentation. In a study of 34 presentation myeloma cases using a sensitive polymerase chain reaction-restriction fragment length polymorphism strategy on enriched tumor cell populations, the present study detected N-ras codon 61 mutation-positive cells in all patients. Quantitative plaque hybridization using allele-specific oligonucleotide probes showed that in the majority of patients, ras mutation-positive cells comprise only a subpopulation of the total malignant plasma cell compartment (range, 12%-100%). Using clonospecific point mutations in the 5′ untranslated region of the BCL6 gene to quantitate clonal B cells in FACS-sorted bone marrow populations from 2 patients, the representation of ras mutation-positive cells was independent of immunophenotype. These observations imply that mutational activation of N-ras codon 61 is a mandatory event in the pathogenesis of multiple myeloma; such mutations provide a marker of intraclonal heterogeneity that may originate at an earlier ontologic stage than immunophenotypic diversification of the malignant B cell clone.
48
Melchor, Lorenzo, John R. Jones, Oleg Lenive, Erich Allen Peterson, Annamaria Brioli, Alex Murison, Christopher P. Wardell, et al. "Spatiotemporal Analysis of Intraclonal Heterogeneity in Multiple Myeloma: Unravelling the Impact of Treatment and the Propagating Capacity of Subclones Using Whole Exome Sequencing." Blood 126, no. 23 (December 3, 2015): 371. http://dx.doi.org/10.1182/blood.v126.23.371.371.
Full textAbstract:
Abstract Introduction Multiple myeloma (MM) is characterised by the malignant expansion of clonal plasma cells in the bone marrow (BM). We and others have used massive parallel sequencing to describe the somatic aberrations acquired in different subclones in newly diagnosed MM (NDMM). These studies have showed that chemotherapy has an impact on intra-clonal heterogeneity, but more analyses are required in paired presentation/relapse samples and samples from multiple sites at the same and different time points. Materials and methods We have studied 49 paired presentation/relapse patients from a series of 463 NDMM patients entered into the Myeloma XI trial (NCT01554852). To understand the impact of spatial separation within the MM clone and the consideration that MM is a metastatic disease, we examined BM aspirates and compared them to targeted biopsies from extramedullary disease sites in 9 MM patients. These cases were 1 patient with samples bilaterally collected from the hip during the course of the disease, 4 MM cases with plasma cell leukemia (PCL), 3 MM cases with plasmacytomas, 1 MM patient with ascites, and 1 MM case with pleural effusion. DNA from both BM and peripheral blood samples were used for whole exome sequencing plus a pull down of the MYC, IGH, IGL and IGK loci following the SureSelect Target Enrichment System for Illumina Paired-End Sequencing Library v1.5. Exome reads were used to call single nucleotide variants, indels, translocations, and copy number aberrations. Mean sequencing depth was 59.3x. The proportion of mutant tumor cells carrying a mutation was inferred. The presence and proportion of subclones will be defined using bioinformatics tools. Results For the 463 NDMM samples, the following 15 significantly mutated genes are seen KRAS (n=103 mutations), NRAS (n=88), LTB (n=53), DIS3 (n=49), BRAF (n=37), EGR1 (n=22), FAM46C (n=20), IRF4 (n=19), TRAF3 (n=17), HIST1H1E (n=16), TP53 and FGFR3 (n=14), CYLD (n=13), MAX (n=12), and RB1 (n=5). These mutations were seen within all clonal cells and at subclonal levels, consistent with the mutations being acquired at different time points and being associated with different subclonal fitness. We show that NDMM have a mean number of exonic mutations of 61.1±13.0, in contrast to samples taken at the time of relapse, which show an average of 80.6±25.4, Figure 1A. We report diverse patterns of subclonal evolution: no change, subclonal tiding, and subclonal tiding with new subclones arising. We are currently examining samples taken during clinical remission to track subclones at the time of response. For patient with multiple samples taken at different timepoints, 77 mutations were shared across all samples but, of note, specific mutations were seen at the same timepoint in different sites (13/1662 R2R vs 13/1662 R2L), which illustrates the impact of sampling differences in reporting mutation calls and differential response to therapy, Figure 1B. This is also observed in a plasmacytoma case with both a BM aspirate sample containing 11 mutations (including NRAS c.183A>T and BRAF c.1783T>C), and a femur plasmacytoma with 18 mutations, of which only 2 are shared with the BM sample, Figure 3. One of these shared lesions is BRAF c.1783T>C, the cancer clonal fraction of which increases ten-fold, suggesting that the sub-clone with this mutation disseminated from the BM and founded the plasmacytoma. Conclusion Our preliminary data demonstrate that MM subclones not only respond differently to clinical treatment, but also have different biological properties leading to cause extramedullary disease. To our knowledge, this is the first comprehensive genetic analysis of the spatio-temporal heterogeneity in myeloma and reveals genetic differences due to sampling bias. Figure 1. (A) Number of mutations in MM patients at clinical presentation and relapse. Each patient sample is represented by a dot. Lines and error bars correspond to the average and the standard error of the mean values, respectively. Difference was not statistically significant (p >0.05, t-test). (B) MM patient analysed at presentation and following two relapses (top). The number of mutations increases through disease (bottom, left panel). Venn plot shows the number of shared and specific mutations for each time point (bottom, right panel). (C) Case with a MM sample (green) and a femur plasmacytoma (blue). Venn plot shows shared and specific mutations to the bone marrow or the plasmacytoma site. Figure 1. (A) Number of mutations in MM patients at clinical presentation and relapse. Each patient sample is represented by a dot. Lines and error bars correspond to the average and the standard error of the mean values, respectively. Difference was not statistically significant (p >0.05, t-test). (B) MM patient analysed at presentation and following two relapses (top). The number of mutations increases through disease (bottom, left panel). Venn plot shows the number of shared and specific mutations for each time point (bottom, right panel). (C) Case with a MM sample (green) and a femur plasmacytoma (blue). Venn plot shows shared and specific mutations to the bone marrow or the plasmacytoma site. Disclosures Jones: Celgene: Other: Travel support, Research Funding. Peterson:University of Arkansas for Medical Sciences: Employment. Brioli:Celgene: Honoraria; Janssen: Honoraria. Pawlyn:Celgene: Honoraria, Other: Travel support; The Institute of Cancer Research: Employment. Gregory:Janssen: Honoraria; Celgene: Honoraria. Davies:Onyx-Amgen: Membership on an entity's Board of Directors or advisory committees; Array-Biopharma: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Takeda-Millennium: Membership on an entity's Board of Directors or advisory committees; University of Arkansas for Medical Sciences: Employment. Morgan:CancerNet: Honoraria; University of Arkansas for Medical Sciences: Employment; MMRF: Honoraria; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Weisman Institute: Honoraria; Bristol Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda-Millennium: Honoraria, Membership on an entity's Board of Directors or advisory committees.
49
Itoh, Yasushi, and Ronald N. Germain. "Single Cell Analysis Reveals Regulated Hierarchical T Cell Antigen Receptor Signaling Thresholds and Intraclonal Heterogeneity for Individual Cytokine Responses of CD4+ T Cells." Journal of Experimental Medicine 186, no. 5 (August 29, 1997): 757–66. http://dx.doi.org/10.1084/jem.186.5.757.
Full textAbstract:
T cell receptor (TCR) recognition of peptide–major histocompatibility complex antigens can elicit a diverse array of effector activities. Here we simultaneously analyze TCR engagement and the production of multiple cytokines by individual cells in a clonal Th1 CD4+ cell population. Low concentrations of TCR ligand elicit only interferon-γ (IFN-γ) production. Increasing ligand recruits more cells into the IFN-γ+ pool, increases IFN-γ produced per cell, and also elicits IL-2, but only from cells already making IFN-γ. Most cells producing only IFN-γ show less TCR downmodulation than cells producing both cytokines, consistent with a requirement for more TCR signaling to elicit IL-2 than to evoke IFN-γ synthesis. These studies emphasize the hierarchical organization of TCR signaling thresholds for induction of distinct cytokine responses, and demonstrate that this threshold phenomenon applies to individual cells. The existence of such thresholds suggests that antigen dose may dictate not only the extent, but also the quality of an immune response, by altering the ratios of the cytokines produced by activated T cells. The quantitative relationships in this response hierarchy change in response to costimulation through CD28 or LFA-1, as well as the differentiation state of the lymphocyte, explaining how variations in these parameters in the face of a fixed antigen load can qualitatively influence immune outcomes. Finally, although the IFN-γ/IL-2 hierarchy is seen with most cells, among cells with the greatest TCR downmodulation, some produce only IFN-γ and not IL-2, and the amount of IFN-γ exceeds that in double producers. Thus, these single cell analyses also provide clear evidence of nonquantitative intraclonal heterogeneity in cytokine production by long-term Th1 cells, indicating additional complexity of T cell function during immune responses.
50
Lossos, Izidore S., and Ronald Levy. "Mutation analysis of the 5′ noncoding regulatory region of the BCL-6 gene in non-Hodgkin lymphoma: evidence for recurrent mutations and intraclonal heterogeneity." Blood 95, no. 4 (February 15, 2000): 1400–1405. http://dx.doi.org/10.1182/blood.v95.4.1400.004k43_1400_1405.
Full textAbstract:
The BCL-6 proto-oncogene is involved in the genesis of non-Hodgkin lymphoma (NHL). Rearrangements due to chromosomal translocations and somatic mutations of the 5′ noncoding regulatory region of the BCL-6 gene are potential mechanisms for altering its expression in NHL. To further elucidate the nature of the somatic mutations in the regulatory region of this gene, we have studied 10 healthy donors and 11 NHL biopsy samples by extensive molecular cloning and sequencing. In addition, we analyzed the BCL-6 genes of tumor and nontumor cells from 2 of the cases. The germ line sequence of this region was defined, which differs in 7 positions from that previously reported. In addition, 1 polymorphic variation at position 397(G or C) was identified. Deletions, insertions, and repeated substitution mutations were detected among the molecular isolates in 8 tumor specimens, with a mutational incidence ranging from 1.3 × 10−3 to 1.3 × 10−2/bp (base pair). A total of 20 distinct substitution mutations, 1 insertion and 3 deletions were observed. One of these deletion mutations and 2 of the substitutions were observed in more than 1 tumor specimen from different individuals. In 3 tumor samples, identical mutations affecting both alleles were observed. These findings suggest the presence of mutational hot spots and hot specific events, a finding supported by our compilation of previously published data. In 6 samples, the nucleotide sequences showed evidence of intraclonal heterogeneity, consistent with a stepwise ongoing mutational process affecting the BCL-6 gene in the tumor cells. These mutations accumulating in the regulatory region of the BCL-6 gene could play a role in lymphoma progression and in the transformation of follicular lymphomas to more aggressive large cell lymphomas.