Dissertations / Theses on the topic 'P53 antioncogene'
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Campbell, Hamish George, and n/a. "The functions of p53 during an adenovirus infection." University of Otago. Dunedin School of Medicine, 2008. http://adt.otago.ac.nz./public/adt-NZDU20080411.115504.
Full textFrancoz, Sarah. "Mdm4 and Mdm2 cooperate to inhibit p53 activity in proliferating and quiescent cells in vivo." Doctoral thesis, Universite Libre de Bruxelles, 2006. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210858.
Full textDoctorat en sciences, Spécialisation biologie moléculaire
info:eu-repo/semantics/nonPublished
Evdokiou, Andreas. "Tumour-suppressive activity of the growth arrest-specific gene, GAS1 /." Title page, contents and summary only, 1997. http://web4.library.adelaide.edu.au/theses/09ph/09PHE928.pdf.
Full textNatan, Eviatar. "Why the tumour suppressor p53 is a tetramer." Thesis, University of Cambridge, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.609555.
Full textChan, Wan Mui. "Regulation of p53 by isoforms, stoichiometry, and ubiquitination /." View abstract or full-text, 2007. http://library.ust.hk/cgi/db/thesis.pl?BICH%202007%20CHANW.
Full textPei, Lim-cho Steven, and 貝念祖. "Role(s) of p53/p63 in chondrocyte re-differentiation upon activation of ER stress." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2012. http://hdl.handle.net/10722/198926.
Full textpublished_or_final_version
Biochemistry
Master
Master of Philosophy
Brandt, Tobias. "Molecular mechanisms of DNA recognition by the tumour suppressor p53." Thesis, University of Cambridge, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.609611.
Full textHe, Dan. "Clinical and pathological significance of HPV infection and p53 mutation in human esophageal cancer /." Hong Kong : University of Hong Kong, 1997. http://sunzi.lib.hku.hk/hkuto/record.jsp?B1961620X.
Full textRussell, Iain Alasdair, and n/a. "Involvement of p53 and Rad51 in adenovirus replication." University of Otago. Dunedin School of Medicine, 2007. http://adt.otago.ac.nz./public/adt-NZDU20070521.094929.
Full textJones, Rhiannon N. "Towards the design and synthesis of a p53 mutant Y220C rescue drug." Thesis, University of Sussex, 2018. http://sro.sussex.ac.uk/id/eprint/74884/.
Full textEhinger, Mats. "On the role of the tumor suppressor gene p53 in leukemic cell differentiation." Lund : Lund University, 1997. http://catalog.hathitrust.org/api/volumes/oclc/68945098.html.
Full textChandrachud, Uma. "Differential interaction of wild type and mutant p53 to promoter sequences and analysis of interacting proteins." Diss., Online access via UMI:, 2009.
Find full textMaloof, Frances Rita. "p53 presentation and other prognostic indicators in oral squamous cell carcinoma." Thesis, The University of Sydney, 1996. http://hdl.handle.net/2123/4649.
Full text何丹 and Dan He. "Clinical and pathological significance of HPV infection and p53 mutation in human esophageal cancer." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1997. http://hub.hku.hk/bib/B31236959.
Full textChen, Xi. "Alternative cell fate in response to DNA damage regulated by differential p53 pathway dynamics." HKBU Institutional Repository, 2012. https://repository.hkbu.edu.hk/etd_ra/1473.
Full textLu, Wenjing, and 鲁文静. "The interaction of mortalin and p53 in human hepatocellular carcinoma." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B46330069.
Full textYam, Hin-cheung Bill, and 任憲章. "p70 S6 kinase regulation of Mdm2 and p53 in ovarian cancer cells during stress conditions." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B47753109.
Full textpublished_or_final_version
Biological Sciences
Master
Master of Philosophy
Chan, Kin Tak. "Investigations of p53 mutations and effects on drug resistance /." View abstract or full-text, 2003. http://library.ust.hk/cgi/db/thesis.pl?BIOL%202003%20CHAN.
Full textAzoulay, Eric. "Induction of apoptosis or cell cycle arrest by two human wildtype variants of the p53 protein." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0031/MQ64313.pdf.
Full textWang, Suwei. "Mechanisms of Cr(VI)-induced carcinogenesis the involvement of reactive oxygen species and signal transduction pathway /." Morgantown, W. Va. : [West Virginia University Libraries], 2001. http://etd.wvu.edu/templates/showETD.cfm?recnum=1803.
Full textTitle from document title page. Document formatted into pages; contains viii, 124 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references.
Zhang, Pingde, and 张萍德. "TAp73α enhances the cellular sensitivity to cisplatin in ovarian cancer cells via the JNK signaling pathway." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B47752944.
Full textpublished_or_final_version
Obstetrics and Gynaecology
Doctoral
Doctor of Philosophy
Low, Eva Oi Wha. "p53 mutations in cultured malignant cells and oral cancers detected in extracted DNA and in situ, investigated by the polymerase chain reaction." Thesis, The University of Sydney, 2003. http://hdl.handle.net/2123/4646.
Full textZhang, Zhuo. "Vanadate-induced cell cycle regulation and its signal transduction pathway." Morgantown, W. Va. : [West Virginia University Libraries], 2002. http://etd.wvu.edu/templates/showETD.cfm?recnum=2524.
Full textTitle from document title page. Document formatted into pages; contains xii, 216 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references.
Maetens, Marion M. "Regulation of the tumor suppressor p53 by Mdm2 and Mdm4." Doctoral thesis, Universite Libre de Bruxelles, 2007. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210602.
Full textMoreover, a large body of evidence indicates that aberrant expression of either MDM2 or MDM4 impairs p53 tumor suppression function and consequently favors tumor formation. Overexpression of MDM2 was observed in 10% of 8000 human cancers from various sites, including lung or stomach, and MDM4 was found amplified and/or overexpressed in 10-20% of over 800 diverse tumors including lung, colon, stomach and breast cancers. Remarkably, selective MDM4 amplification occurs in about 65% of human retinoblastomas. In contrast, MDM2 amplifications are relatively rare (about 5%) in retinoblastomas, indicating that depending on the tumor context (cell type, initiating oncogene, …), MDM4, rather than MDM2, overexpression might be selected for as a more efficient mean of suppression of p53 function. As part of a large effort to better understand why different cell types require distinct combinations of mutations to form tumours, we will examine the molecular basis for selective up-regulation of Mdm4 in retinoblastomas. In this context, we have successfully generated 2 conditional transgenic mouse lines expressing either mycMdm2 or mycMdm4 driven by the PCAGGs promoters in the ROSA26 locus. Since a cassette containing a floxed transcriptional stop element is inserted upstream of the transgenes, we can achieve tissue-specific expression and spatio-temporal regulation of the transgenes by using different Cre and CreER. By the use of N-terminal myc-tag fused with the transgenes, we are able to compare the expression levels of the transgenes. Finally, due to C-terminal IRES-GFP element, we can easily identify transgene expressing cells. One of our aims is to use this Mdm4 conditional transgenic mouse line as the first, non-chimeric, mouse model of retinoblastoma that can be used as an appropriate preclinical model to improve treatment of this disease.
Doctorat en Sciences
info:eu-repo/semantics/nonPublished
Yoon, Heejei. "New insights into cancer genes haploinsufficiency and noncoding RNA in human cancer /." Columbus, Ohio : Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1155149683.
Full textSchmerr, Martin J. "THE FUNCTIONAL SIGNIFICANCE OF AN ALTERNATELY SPLICED PRODUCT OF THE HDM2GENE." Ohio : Ohio University, 2007. http://www.ohiolink.edu/etd/view.cgi?ohiou1173370332.
Full textBillant, Olivier. "Utilisation de la levure S. cerevisiae pour déchiffrer les mécanismes de l'effet dominant-négatif affectant la famille de gènes suppresseurs de tumeurs p53, p63 et p73." Thesis, Brest, 2016. http://www.theses.fr/2016BRES0055/document.
Full textP53 is a ubiquitous tumor suppressor gene that prevents damaged cells from proliferating. Following DNA damage or cellular stress, p53 induces a cell cycle arrest and initiates an attempt to repair the lesions. If the repair fails, p53 triggers the apoptosis of the cell. p53 shares a high homology with two other tumor suppressor genes: p63 and p73. Together they form a family of transcription factors, which are actively protecting the organism from tumor development. This defense network is enriched by multiple N-terminal and C-terminal isoforms of p53, p63 and p73. The loss of p53, p63 and p73 tumor suppression function is a key step of cancer progression. Mutants of p53 and isoforms of p53, p63 and p73 often exhibit a dominant-negative behavior resulting in the loss of p53 tumor suppression activity. However, the extent of the dominant-negative effect within p53 family remains unclear. The mechanisms behind the dominant-negative effect are also debated due to the recent emergence of a prion-like hypothesis. Finally, the dominant-negative effect of p53 family members could be involved in other pathologies such as p63-related developmental syndromes During this PhD, I studied the functional consequences of hotspot mutations of p53 and of the main isoforms of the p53 family on the transcriptional activity of p53, p63 and p73. Using the naïve eukaryotic model S. cerevisiae we have demonstrated that the dominant-negative effect of mutants and isoforms of the p53 family relies on the formation of hetero-tetramers between functional and non-functional members of the family but not on a prion-like mechanism. In addition, certain p53 mutants are able to interfere with p63 and p73 isoforms though a mechanism that is only partially based on tetramerization. Of note, we obtained preliminary results suggesting that mutants of p63, which are involved in EEC, ADULT and NSCL1 developmental syndromes, behave like dominant-negative hotspot mutants of p53. The identification of the mechanisms of the dominant-negative effect occurring within p53 family could lead to new therapeutic targets both in cancer and in rare developmental syndromes.1 EEC : ectrodactyly, ectodermal dysplasia and cleft lip/palate syndrome, ADULT : acro-dermato-ungual-lacrimal-tooth syndrome, NSCL : non-syndromic cleft lip
Kalita, Ann Marie. "Comparison of the activities of two allelic variants of the human wildtype p53 protein." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/mq29729.pdf.
Full textGadéa, Gilles. "Etude des mécanismes de contrôle de la migration cellulaire par le gène suppresseur de tumeurs p53." Montpellier 2, 2004. http://www.theses.fr/2004MON20083.
Full textPortefaix, Jean-Michel. "Apport des immunotechnologies à l'analyse structurale et sérologique de la protéine P53." Montpellier 1, 1999. http://www.theses.fr/1999MON13519.
Full textMcKay, Bruce C. "The relationship between the repair of ultraviolet light induced DNA damage in human cells and the p53 tumour suppressor /." *McMaster only, 1997.
Find full textMolès, Jean-Pierre. "Le gène TP53 et la physiologie cutanée." Montpellier 1, 1993. http://www.theses.fr/1993MON1T018.
Full textJoubel, Anita. "Analyse protéomique du suppresseur de tumeur p53 : modifications post-traductionelles et protéines partenaires." Thesis, Lille 1, 2008. http://www.theses.fr/2008LIL10035.
Full textThe tumor suppressor protein p53 is involved in many signaling pathways and is the most frequently mutated protein in cancers. The mechanisms for the regulation of p53 activity involve post-translational modifications and partner proteins for which literature is phletoric and fragmentary. ln the present study, we have developed a proteomics approach, coupling immunoprecipitation and mass spectrometry, to investigate p53 post-translational modifications and protein partners. First, we sequenced the full p53 protein immunoprecipitated from the Cos-l cells. This lead to the identification and localization of several known phosphorylations on serine residues S 15, S33, S315 and S392 as weIl as several known acetylations on lysine residues: K305, K370, K372, K373, K381 and K382. Acetylation sites are being reported for the tirst time on monkey p53 from Cos-l cells on lysine 319,357 and 386. Second, we looked for partner proteins that can bind to p53 in non cancerous (MCFlOA cells) versus cancerous (MCF7) human breast epithelial cells. Our results report a series of putative interacting partners among which the serine protease inhibitor maspin. The complex between p53 and maspin was validated by westem-blotting, localized in the nucleus and found in the noncancerous MCFlOA cells only. The p53/maspin interaction could represent a new regulatory mechanism for the activity of p53
Flaman, Jean-Michel. "La levure Saccharomyces cerevisiae : un modèle pour l'étude de l'activité transcriptionnelle de p53 et de son altération dans les cancers." Rouen, 1997. http://www.theses.fr/1997ROUES084.
Full textPoirson, Juline. "Interactome des oncoprotéines E6 et E7 des HPV : du système ubiquitine-protéasome à la voie de signalisation Hippo." Thesis, Strasbourg, 2016. http://www.theses.fr/2016STRAJ052.
Full textThe human papillomavirus (HPVs) are the archetype of DNA oncogenic viruses. High-risk mucosal HPVs (mainly HPV16) are the main causative agents of cervical cancer and are also involved in other cancers. HPV oncogenic properties are mainly due to the expression of E6 and E7 proteins. We built a resource composed of 600 cDNA encoding the human ubiquitin-proteasome system (UPS) effectors and identified novel E6 and E7 potential targets by using a method based on the complementation of the Gaussia princeps luciferase (GPCA). HPV16 E6 binds to specific LxxLL motifs present in E6AP and IRF3. We have solved the crystallographic structure of the E6/E6AP LxxLL/p53 and E6/IRF3 LxxLL complexes. Furthermore, HPV may target a novel tumour suppressor pathway, the Hippo signalling pathway with its two main mediators YAP and TAZ. We have built a cDNA library dedicated to the 265 human PDZ domains and identified news potential partners of YAP and TAZ proteins by using the GPCA. The results provide novel insights on HPV biology and their oncogenic property
Guérillon, Claire. "Les protéines suppressives de tumeurs ING1, ING2 et ING3 : régulation par sumoylation et implication dans la réponse aux dommages à l'ADN." Thesis, Rennes 1, 2014. http://www.theses.fr/2014REN1S181.
Full textING (Inhibitor of Growth) genes are tumor suppressor gene candidates conserved from Yeast to Humans. ING proteins have type I tumor suppressive functions or "caretaker" because they participate in the maintenance of genome stability by regulating DNA replication and repair processes. They have also tumor suppressive functions of type II or "gatekeeper" because they are involved in the regulation of cell proliferation in p53 dependent and independent manners. They also participate in the regulation of gene transcription by regulating chromatin remodeling. The aim of my thesis was to better understand how ING1, ING2 and ING3 are involved in tumor suppressive pathways. Our work shows that ING1 is sumoylated on lysine 193 mainly by the SUMO E3 ligase PIAS4 to regulate ING1 anchoring on target gene promoters to control gene transcription. We have also described the involvement of ING2 and ING3 in the DNA double strand breaks response. We show the conservation of this function between ING2, ING3 and their orthologs, respectively, Pho23 and Yng2 in Yeast Saccharomyces cerevisiae. ING2 controls the accumulation of PIAS4 at DNA damage sites and regulates the sumoylation of the E3 ubiquitin ligase RNF168, to regulate DNA double strand break signaling and repair. ING3 is necessary for the accumulation of 53BP1 and promotes DNA damage repair. This work contributes to a better understanding of the role of ING proteins in tumor suppression. It thus provides new insights of how ING1 regulates gene transcription and emphasizes a new tumor suppressive function of type I or "caretaker" for ING2 and ING3 in the genome stability maintenance
Raad, Sabine. "Développement de nouveaux tests fonctionnels d'aide à l'interpretation des variants de signification biologique inconnue dans le cadre de prédispositions génétiques au cancer." Thesis, Normandie, 2018. http://www.theses.fr/2018NORMR079.
Full textThe identification of the constitutional mutation responsible for a genetic predisposition to cancer is essential to the clinical management of the patient and its relatives. With the implementation of high-throughput sequencing to the diagnostic routine of these pathologies, the challenge no longer lies within the detection of alterations but in their biological and clinical interpretation. While specific treatments are emerging, simple functional assays to help with the interpretation of the detected variants are needed. In this context, we used a functional test developed by our team to classify variations in the TP53 gene responsible for Li-Fraumeni syndrome and to understand the genotype-phenotype correlation in LFS patients. On the other hand, we assessed the relevance of a multi-omic approach (RNA-Seq and metabolomics) to discriminate wild-type cells from cells with a deleterious heterozygous mutation in TP53 or in the BRCA genes implicated in genetic predisposition to breast and ovarian cancers. Based on the transcriptomic data, a mathematical model has been developed to detect variants corresponding to deleterious mutations. Then we selected the most discriminating biomarkers and integrated them into a RT-MLPA functional assay dedicated to the p53 pathway. We finally adapted this test to be feasible on a simple blood test, without immortalization of the patient's lymphocytes
Ou, Yang. "Dissecting the role of p53-mediated metabolic regulation in tumor suppression." Thesis, 2016. https://doi.org/10.7916/D8BZ66K5.
Full textSaleem, Ayesha. "Role of p53 in mitochondrial biogenesis and apoptosis in skeletal muscle /." 2008. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:MR38823.
Full textTypescript. Includes bibliographical references (leaves 71-78). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:MR38823
Riley, Todd Robert. "Modeling p53 transcriptional regulation." 2008. http://hdl.rutgers.edu/1782.2/rucore10001600001.ETD.17551.
Full textCheng, Ronshan. "Ras oncogenes and p53 suppressor genes in fish carcinogenesis models." Thesis, 1995. http://hdl.handle.net/1957/27187.
Full textGraduation date: 1996
"ZBP-89 regulates Bak expression via epigenetic mechanism." 2013. http://library.cuhk.edu.hk/record=b5549831.
Full text肝癌是非常高死亡率的恶性肿瘤之一。由于传统化疗方式的局限性,表观遗传治疗方法可能成为肝癌治疗的替代方法。研究报道ZBP-89诱导肝癌细胞Bak的表达,表观调控是否参与该诱导作用,目前仍然不清楚。
HDAC3被认为是化疗靶点和肝癌复发的肿瘤标记物。它常常在肝癌组织中高表达,对HDAC3的抑制作用可以增加肝癌的化疗效果。我们的研究表明ZBP-89可以降低肝癌细胞HDAC3的表达,但机制未明。蛋白的翻译后调控是细胞生化过程的重要调节因素。所以,研究调节HDAC3的降低途径对肝癌的发生和复发具有非常重要的研究意义。
本研究旨在研究ZBP-89调控Bak表达的表观遗传机制。同时,弄清楚DNA甲基化转移酶和组蛋白去乙酰化酶是否参与ZBP-89对Bak的调控作用,进一步阐明ZBP-89对HDAC3降低通路的机制。
方法和结果
肝癌病人组织蛋白分析表明,相对于癌旁组织,肝癌组织Bak和ZBP-89蛋白表达降低,而DNMT1和HDAC3表达升高。免疫共沉淀技术显示ZBP-89与HDAC3、 DNMT1结合,但不与HDAC4, DNMT3a和DNMT3b结合。相应地,HDAC3和 DNMT1免疫沉淀分析也显示三者形成免疫复合物。我们在肝癌细胞中过表达ZBP-89,验证它会不会影响HDACs和DNMTs的活性。实验结果表明过表达的ZBP-89抑制HDACs和DNMTs的活性。进一步发现ZBP-89调节的Bak表达可能是通过抑制HDACs活性和维持组蛋白H3和H4乙酰化水平实现的。另一方面,我们同样证明HDAC的抑制剂(HDACi)VPA和TSA可以诱导肝癌细胞Bak表达,此外,siRNA干扰HDAC3的表达同样可以诱导Bak表达。
对DNMT1表达的抑制和使用DNMT抑制剂(DNMTi)Zebularine也可以诱导Bak的表达。染色质免疫沉淀结果显示ZBP-89结合于Bak的启动子区域,从-3188bp到-3183bp,从-275到-49。 ZBP-89可以抑制DNMT的活性,那么ZBP-89是否会影响DNA中CpG岛甲基化状态和甲基化结合蛋白(MeCP2)的结合能力,这一点仍需要进一步证实。结果表明ZBP-89可以抑制MeCP2结合基因组DNA。为进一步揭示MeCP2是否由于启动子区域CpG岛去甲基化影响其结合能力,我们采用亚硫酸盐测序方法。测序结果显示ZBP-89过表达可以影响Bak启动子CpG岛的甲基化状态,并促进其去甲基化。
腺病毒介导的ZBP-89过表达降低HDAC3表达呈现剂量依赖性,然而HDAC3 的mRNA水平并没有受到ZBP-89的表达。免疫共沉淀方法和蛋白免疫印迹实验用于分析Pin1和HDAC3复合物,磷酸化IκB和HDAC3复合物的结合情况。结果表明Pin1结合HDAC3并促进HDAC3的减少。同时,HDAC3与磷酸的IκB结合并进入蛋白减少途径。
构建的mU6-siPin1表达质粒用于敲除肝癌细胞Pin1的表达,方法检测基因表达水平。Pin1的缺失表达阻碍ZBP-89介导的HDAC3降低。在Pin1 敲除细胞系 JB6 C141 Pin1⁻/⁻ 和Pin1过表达细胞系的研究,ZBP-89更加能促进Pin1⁺/⁺细胞中HDAC3减少,而对Pin1⁺/⁺的细胞则没那么明显。由此肯定了Pin1在ZBP-89介导的HDAC3降低中的重要作用。进一步研究发现, IκB激酶 (IKK)抑制剂,CAY10576,能抑制 ZBP-89介导的HDAC3的降低;而SN50, p65/p50人核抑制多肽,则不影响HDAC3的降低。研究结果证明HDAC3的降低依赖IκB通路,而不是NF- κB活性。
我们用人肝癌细胞的裸鼠移植瘤模型研究ZBP-89调控Bak表达的表观遗传机制,及其对肝癌的治疗效果。研究结果表明ZBP-89蛋白和组蛋白抑制剂VPA和DNA甲基化抑制zebularine都能抑制肿瘤的生长,并诱导肿瘤组织Bak表达及细胞凋亡。VPA和zebularine联合治疗的效果更好。研究也表明ZBP-89可以在体内降低HDAC3蛋白水平。
结论
本研究揭示了ZBP-89调节Bak蛋白表达和肝癌细胞凋亡的表观遗传机制。同时,进一步揭示ZBP-89联合Pin1经由IκB通路调节HDAC3降低的机制. 本研究为肝癌表观遗传学的治疗提供研究基础和科学依据。
Background
Hepatocellular carcinoma (HCC) is one of the most prevalent malignancies worldwide with a very high mortality. Because the success of the conventional therapies is limited, epigenetic therapy may represent an alternative for HCC management. ZBP-89 is known to induce Bak in HCC. However, it is unclear whether epigenetic mechanisms contribute to ZBP-89-mediated Bak.
Histone acetylase 3 (HDAC3) is realized as a chemotherapy target and a biomarker of recurrence in HCC. HDAC3 is frequently overexpressed in HCC and its inhibition enhances the efficacy of anti-HCC chemotherapy. The pilot data have indicated that ZBP-89 reduced HDAC3 in HCC but the mechanism responsible was unknown. The post-translational modification of proteins functions as a key regulatory factor in cellular physiological procedures, such as ubiquitinoylation degradation. As a biomarker of HCC development and recurrence, it is important to understand how ZBP-89 mediates the reduction of HDAC3.
This study focuses on if ZBP-89 regulates Bak expression through epigenetic mechanisms. It is designed to investigate whether DNA methyltransferases (DNMTs), histone acetylases (HDACs) are involved in regulation of ZBP-89-induced Bak expression. The study also elucidates the mechanism how ZBP-89 reduces the level of HDAC3 protein.
Methods and Results
The levels of Bak and ZBP-89 as shown on western blots were reduced but DNMT1 and HDAC3 were increased in HCC cancer tissues compared to the corresponding non-cancer tissues. Co-immunoprecipitation experiments showed that ZBP-89 bound to HDAC3 and DNMT1 but not other epigenetic enzymes, such as HDAC4, DNMT3a and DNMT3b. To clarify if ZBP-89 affects the activities of HDACs and DNMTs, ZBP-89 was overexpressed in HCC cells. Enzyme activities of HDACs and DNMTs were determined using relevant assay kits. Results showed that overexpressed ZBP-89 inhibited the activities of HDACs and DNMTs. Further experiments indicated that ZBP-89-mediated Bak up-regulation might contribute to maintenance of histone H3 and H4 acetylation through inhibition of HDACs activity. In another set of experiments, we also found an increased Bak expression in HCC cells when the cells were treated with HDAC inhibitors (HDACi) VPA and TSA. HDAC3 siRNA also increased Bak expression.
Both knockdown of DNMT1 expression and administration of DNMTs inhibitors (zebularine) induced Bak expression. Chromatin immunoprecipitation (ChIP) showed that ZBP-89 bound to Bak promoter at the region from -3188bp to -3183bp and from -275 to -49. As ZBP-89 inhibits DNMT activity, it is essential to know whether its inhibition affectes DNA CpG methylation status and methyl-CpG binding protein (MeCP) binding. The results showed that ZBP-89 overexpression inhibited MeCP2 binding to genomic DNA. The finding indicated that decreased MeCP2 binding to DNA might be due to decreased methyl-CpG number in Bak promoter, suggesting that ZBP-89 might affect CpG island methylation status. Therefore, the bisulfite modified DNA sequencing method was used to clarify if Bak promoter CpG island methylation status was altered after ZBP-89 overexpression. Results revealed that ZBP-89 overexpression could demethylate the CpG islands in Bak promoter.
ZBP-89 overexpression dose-dependently reduced the expression of HDAC3 at protein level but not at mRNA level. Co-immunoprecipitation and western blot methods were used to analyze Peptidyl-prolyl cis/trans isomerase 1 (Pin1) and HDAC3, phospho-I kappa B (pIκB), and the result revealed that HDAC3 could bound with either Pin1 or pIκB to promote the reduced expression of HDAC3.
Constructed mU6-siPin1 vector was used to knockdown Pin1 expression in HCC cells. We found that knockdown of Pin1 expression blocked ZBP-89-mediated HDAC3 reduction. Experiments performed in Pin1 allele-knockdown JB6 C141 Pin1⁻/⁻ and Pin1⁺/⁺ cells showed that the reduction of HDAC3 by ZBP-89 was greater in Pin1⁺/⁺ cells than in Pin1⁻/⁻ cells, confirming the role of Pin1 in ZBP-89-mediated HDAC3 reduction. Furthermore, the ZBP-89-mediated HDAC3 reduction was suppressed by CAY10576, an IκB kinase (IKK) activation inhibitor but not by SN50, a p65/p50 translocation inhibitor, suggesting that HDAC reduction may depend on IκB kinase rather than NF-κB activity.
HCC xenograft mouse model was used to support the involvement of epigenetic mechanism in ZBP-89-induced Bak expression and its therapeutic effects against HCC. Results showed that ZBP-89 as well as HDAC inhibitor valproic acid (VPA) or/and DNMT inhibitor zebularine stimulated Bak expression and induced apoptosis of tumor cells in an HCC xenograft mouse model, arresting tumor growth. In HCC xenografe model, treatment by injection of Ad-ZBP-89 viral expression vector mediated ZBP-89 expression decreased HDAC3 expression, but not HDAC4.
Conclusions
In conclusion, the study demonstrates a novel mechanism through which ZBP-89 mediates an epigenetic pathway to promote Bak expression, and induce apoptosis in HCC cells. It also reveals the mechanism of HDAC3 reduction by ZBP-89 is dependent on IκB, which requires the presence of Pin1. This pathway may help develop future epigenetic therapy against HCC.
Detailed summary in vernacular field only.
Detailed summary in vernacular field only.
Detailed summary in vernacular field only.
Detailed summary in vernacular field only.
Detailed summary in vernacular field only.
Detailed summary in vernacular field only.
Detailed summary in vernacular field only.
Detailed summary in vernacular field only.
Detailed summary in vernacular field only.
Detailed summary in vernacular field only.
Detailed summary in vernacular field only.
Detailed summary in vernacular field only.
Ye, Caiguo.
Thesis (Ph.D.)--Chinese University of Hong Kong, 2013.
Includes bibliographical references (leaves 123-140).
Abstracts also in Chinese.
Abstract --- p.i
摘要 --- p.v
Publications --- p.viii
Acknowledgements --- p.ix
Abbreviations --- p.xi
List of Tables --- p.xiii
List of figures --- p.xiv
Chapter Chapter One: --- General Introduction --- p.1
Chapter 1.1 --- Background --- p.2
Chapter 1.2 --- The complexity of HDAC family and functions --- p.3
Chapter 1.2.1 --- HDAC family --- p.4
Chapter 1.2.2 --- Multifunction of HDACs --- p.6
Chapter 1.3 --- HDACs and apoptosis --- p.6
Chapter 1.3.1 --- HDAC regulates apoptotic-related gene expression --- p.9
Chapter 1.3.2 --- HDACs regulate apoptosis through protein complexes --- p.18
Chapter 1.3.3 --- HDACs mediates non-histone deacetylation and apoptosis --- p.21
Chapter 1.3.4 --- HDACs degradation deficiency and apoptosis --- p.24
Chapter 1.4 --- DNMTs and epigenetic modification --- p.25
Chapter 1.4.1 --- DNMT family --- p.25
Chapter 1.4.2 --- CpG islands methylation and HCC --- p.26
Chapter 1.5 --- Perspectives --- p.28
Chapter Chapter Two: --- ZBP-89 up-regulates Bak expression through inhibition the activity of HDACs and DNMTs --- p.30
Chapter 2.1 --- Introduction --- p.31
Chapter 2.2 --- Materials and Methods --- p.33
Chapter 2.2.1 --- Hepatocellular carcinoma patient samples and cell lines --- p.33
Chapter 2.2.2 --- Chemicals and reagents --- p.34
Chapter 2.2.3 --- Cell proliferation --- p.34
Chapter 2.2.4 --- Adenovirus infection of cells --- p.35
Chapter 2.2.5 --- Apoptosis detection --- p.36
Chapter 2.2.6 --- Transfection of siRNA and plasmid --- p.36
Chapter 2.2.7 --- Co-immunoprecipitation (co-IP) --- p.37
Chapter 2.2.8 --- Western blotting --- p.37
Chapter 2.2.9 --- Immunohistochemistry and Immunofluorescence --- p.38
Chapter 2.2.10 --- Chromatin immunoprecipitation --- p.38
Chapter 2.2.11 --- Sodium bisulfite modified sequencing of Bak promoter --- p.40
Chapter 2.2.12 --- Histone deacetylase activity assay --- p.41
Chapter 2.2.13 --- DNA methyltransferases enzyme activity --- p.42
Chapter 2.2.14 --- Xenograft animal model --- p.43
Chapter 2.2.15 --- Statistical analysis --- p.43
Chapter 2.3 --- Results --- p.45
Chapter 2.3.1 --- ZBP-89 interacts with DNMT1 and HDAC3 --- p.45
Chapter 2.3.2 --- DNA methyltransferase-1 and histone deacetylase 3 are overexpressed in cancer tissues --- p.48
Chapter 2.3.3 --- Inhibition of HDACs and DNMTs induces Bak expression and apoptosis --- p.58
Chapter 2.3.4 --- Adenovirus mediated ZBP-89 expression inhibits HDACs activity --- p.65
Chapter 2.3.5 --- ZBP-89 suppresses DNMTs activity --- p.67
Chapter 2.3.6 --- Overexpressed ZBP-89 demethylates methyl-CpG islands --- p.69
Chapter 2.3.7 --- Downregulation of HDAC3 and DNMT1 enhances Bak expression --- p.74
Chapter 2.3.8 --- Xenograft nude mouse model reveals that Ad-ZBP-89 adenovirus diminishes tumor volume and induces Bak expression and apoptosis --- p.75
Chapter 2.4 --- Discussion --- p.81
Chapter Chapter Three: --- ZBP-89 targets IkappaB to reduce HDAC3 via a Pin1-dependent pathway --- p.86
Chapter 3.1 --- Introduction --- p.87
Chapter 3.2 --- Materials and Methods --- p.89
Chapter 3.2.1 --- Cell lines, chemicals and reagents --- p.89
Chapter 3.2.2 --- Transfection of siRNA plasmid --- p.89
Chapter 3.2.3 --- Plasmid extraction by mini-prep --- p.90
Chapter 3.2.4 --- Co-immunoprecipitation (co-IP) and Western blotting --- p.91
Chapter 3.2.5 --- Total RNA extraction --- p.92
Chapter 3.2.6 --- Reverse transcription and real-time PCR --- p.93
Chapter 3.2.7 --- Immunohistochemistry and Immunofluorescence --- p.94
Chapter 3.2.8 --- Xenograft animal model --- p.95
Chapter 3.2.9 --- Statistical analysis --- p.95
Chapter 3.3 --- Results --- p.97
Chapter 3.3.1 --- ZBP-89 overexpression diminishes HDAC3 expression but not HDAC4 --- p.97
Chapter 3.3.2 --- Knockdown of Pin1 blocks ZBP-89-mediated HDAC3 reduction --- p.99
Chapter 3.3.3 --- ZBP-89 reduces the level of IκB --- p.103
Chapter 3.3.4 --- IκB degradation inhibitors suppresses ZBP-89-meditaed HDAC3 reduction --- p.105
Chapter 3.3.5 --- ZBP-89 decreases HDAC3 but increases Bak in xenograft tumor tissues --- p.111
Chapter 3.4 --- Discussion --- p.115
Chapter Chapter Four: --- Conclusions and Future Perspectives --- p.119
Chapter 4.1 --- Summary of results --- p.120
Chapter 4.2 --- Conclusions --- p.121
Chapter 4.3 --- Future Perspectives --- p.121
References --- p.123
Liu, Zen. "The effect of matrix stiffness, composition, and three-dimensionality on p53 expression in engineered human bone tumors." Thesis, 2018. https://doi.org/10.7916/D8CG02P2.
Full textXue, Chengyuan School of Women?s & Children?s Health UNSW. "The role of p53 in the drug resistance phenotype of childhood neuroblastoma." 2007. http://handle.unsw.edu.au/1959.4/40876.
Full text"ZBP-89 expression in hepatocellular carcinoma and its interaction with mutant p53." Thesis, 2011. http://library.cuhk.edu.hk/record=b6075357.
Full textThesis (Ph.D.)--Chinese University of Hong Kong, 2011.
Includes bibliographical references (leaves ).
Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Abstract also in Chinese.
Cele, Nosipho Magnificat. "Computational studies on the identification and analyses of p53 cancer associated mutations." Thesis, 2017. http://hdl.handle.net/10321/2617.
Full textP53 is a tumour suppressor protein that is dysfunctional in most human cancer cells. Mutations in the p53 genes result in the expression of mutant proteins which accumulate to high levels in tumour cells. Several studies have shown that majority of the mutations are concentrated in the DNA-binding domain where they destabilize its conformation and eliminate the sequence- specific DNA-binding to abolish p53 transcription activities. Accordingly, this study involved an investigation of the effects of mutations associated with cancer, based on the framework of sequences and structures of p53 DNA-binding domains, analysed by SIFT, Pmut, I-mutant, MuStab, CUPSAT, EASY-MM and SDM servers. These analyses suggest that 156 mutations may be associated with cancer, and may result in protein malfunction, including the experimentally validated mutations. Thereafter, 54 mutations were further classified as disease- causing mutations and probably have a significant impact on the stability of the structure. The detailed stability analyses revealed that Val143Asp, Ala159Pro, Val197Pro, Tyr234Pro, Cys238Pro, Gly262Pro and Cys275Pro mutations caused the highest destabilization of the structure thus leading to malfunctioning of the protein. Additionally, the structural and functional consequences of the resulting highly destabilizing mutations were explored further using molecular docking and molecular dynamics simulations. Molecular docking results revealed that the p53 DNA-binding domain loses its stability and abrogates the specific DNA-binding as shown by a decrease in binding affinity characterized by the ZRANK scores. This result was confirmed by the residues Val143Asp, Ala159Pro, Val197Pro, Tyr234Pro and Cys238Pro p53-DNA mutant complexes inducing the loss of important hydrogen bonds, and introduced non-native hydrogen bonds between the two biomolecules. Furthermore, Molecular dynamics (MD) simulations of the experimental mutant forms showed that the structures of the p53 DNA-binding domains were more rigid comparing to the wild-type structure. The MD trajectories of Val134Ala, Arg213Gly and Gly245Ser DNA-binding domain mutants clearly revealed a loss of the flexibility and stability by the structures. This might affect the structural conformation and interfere with the interaction to DNA. Understanding the effects of mutations associated with cancer at a molecular level will be helpful in designing new therapeutics for cancer diseases.
M
Zilfou, Jack T. "The co-repressor Sin3 interacts with the proline-rich domain of p53 and enhances p53-mediated growth suppression /." Diss., 2001. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3036287.
Full textBatuello, Christopher N. "Phospho-regulation and metastatic potential of Murine Double Minute 2." Thesis, 2012. http://hdl.handle.net/1805/3195.
Full textMurine double minute (Mdm2) is a highly modified and multi-faceted protein that is overexpressed in numerous human malignancies. It engages in many cellular activities and is essential for development since deletion of mdm2 is lethal in early stages of embryonic development. The most studied function of Mdm2 is as a negative regulator of the tumor suppressor protein p53. Mdm2 achieves this regulation by binding to p53 and inhibiting p53 transcriptional activity. Mdm2 also functions as an E3 ubiquitin ligase that signals p53 for destruction by the proteasome. Interestingly recent evidence has shown that Mdm2 can also function as an E3 neddylating enzyme that can conjugate the ubiquitin-like molecule, nedd8, to p53. This modification results in inhibition of p53 activity, while maintaining p53 protein levels. While the signaling events that regulate Mdm2 E3 ubiquitin ligase activity have been extensively studied, what activates the neddylating activity of Mdm2 has remained elusive. My investigations have centered on understanding whether tyrosine kinase signaling could activate the neddylating activity of Mdm2. I have shown that c-Src, a non-receptor protein tyrosine kinase that is involved in a variety of cellular processes, phosphorylates Mdm2 on tyrosines 281 and 302. This phosphorylation event increases the half-life and neddylating activity of Mdm2 resulting in a neddylation dependent reduction of p53 transcriptional activity. Mdm2 also has many p53-independent cellular functions that are beginning to be linked to its role as an oncogene. There is an emerging role for Mdm2 in tumor metastasis. Metastasis is a process involving tumor cells migrating from a primary site to a distal site and is a major cause of morbidity and mortality in cancer patients. To date, the involvement of Mdm2 in breast cancer metastasis has only been correlative, with no in vivo model to definitively define a role for Mdm2. Here I have shown in vivo that Mdm2 enhances breast to lung metastasis through the up regulation of multiple angiogenic factors, including HIF-1 alpha and VEGF. Taken together my data provide novel insights into important p53-dependent and independent functions of Mdm2 that represent potential new avenues for therapeutic intervention.
Phatak, Amruta Rajendra. "Modeling cancer predisposition: Profiling Li-Fraumeni syndrome patient-derived cell lines using bioinformatics and three-dimensional culture models." 2015. http://hdl.handle.net/1805/8037.
Full textAlthough rare, classification of over 200 hereditary cancer susceptibility syndromes accounting for ~5-10% of cancer incidence has enabled the discovery and understanding of cancer predisposition genes that are also frequently mutated in sporadic cancers. The need to prevent or delay invasive cancer can partly be addressed by characterization of cells derived from healthy individuals predisposed to cancer due to inherited "single-hits" in genes in order to develop patient-derived samples as preclinical models for mechanistic in vitro studies. Here, we present microarray-based transcriptome profiling of Li-Fraumeni syndrome (LFS) patient-derived unaffected breast epithelial cells and their phenotypic characterization as in vitro three-dimensional (3D) models to test pharmacological agents. In this study, the epithelial cells derived from the unaffected breast tissue of a LFS patient were cultured and progressed from non-neoplastic to a malignant stage by successive immortalization and transformation steps followed by growth in athymic mice. These cell lines exhibited distinct transcriptomic profiles and were readily distinguishable based upon their gene expression patterns, growth characteristics in monolayer and in vitro 3D cultures. Transcriptional changes in the epithelial-to-mesenchymal transition gene signature contributed to the unique phenotypes observed in 3D culture for each cell line of the progression series; the fully transformed LFS cells exhibited invasive processes in 3D culture with disorganized morphologies due to cell-cell miscommunication, as seen in breast cancer. Bioinformatics analysis of the deregulated genes and pathways showed inherent differences between these cell lines and targets for pharmacological agents. After treatment with small molecule APR-246 that restores normal function to mutant p53, we observed that the neoplastic LFS cells had reduced malignant invasive structure formation from 73% to 9%, as well as an observance of an increase in formation of well-organized structures in 3D culture (from 27% to 91%) by stereomicroscopy and confocal microscopy. Therefore, the use of well-characterized and physiologically relevant preclinical models in conjunction with transcriptomic profiling of high-risk patient derived samples as a renewable laboratory resource can potentially guide the development of safer and more effective chemopreventive approaches.
Hansen, Roseanne S. "Mechanisms by which p53 suppresses cell transformation." Phd thesis, 1995. http://hdl.handle.net/1885/141427.
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