Academic literature on the topic 'Delayed OCRI'

We infused submaximal feedback doses of either dexamethasone (DEX; 0.1 microgram.kg-1.min-1) or corticosterone and cortisol (B+F; 1.5 micrograms.kg-1.min-1) intravenously for 40 min into conscious dogs and measured the adrenocorticotropic hormone (ACTH) responses to hypoglycemia induced by insulin (0.1 U/kg) or to ovine corticotropin-releasing factor (oCRF; 1 microgram/kg); both agents were injected at 120 min. The dose of DEX was chosen to produce suppression of the ACTH response to oCRF equivalent to that produced by B+F. The purpose of the study was to determine 1) whether CRF- and hypoglycemia-induced ACTH secretion are equally inhibited by glucocorticoid treatment and 2) whether DEX and B+F have differential effects in the inhibition of stress-induced ACTH secretion. We found that peak ACTH responses to hypoglycemia and CRF were equally inhibited by DEX (36 +/- 6 and 52 +/- 9%, respectively). The peak ACTH responses to hypoglycemia and CRF were also equally inhibited after B+F infusion (45 +/- 13 and 65 +/- 5%, respectively). There was no significant interaction between the steroid administered and the stimulus given in controlling the ACTH response (by 2-way analysis of variance). The results suggest that pituitary feedback is of primary importance in suppression of canine ACTH secretion by delayed feedback and that the natural and synthetic steroids both act at this site.

Abstract On-patent and off-patent drugs with previously unrecognized anticancer activity could be rapidly repurposed for this new indication given their prior toxicity testing. To identify such compounds, we conducted chemical screens and identified the antihelmintic flubendazole. Flubendazole induced cell death in leukemia and myeloma cell lines and primary patient samples at nanomolar concentrations. Moreover, it delayed tumor growth in leukemia and myeloma xenografts without evidence of toxicity. Mechanistically, flubendazole inhibited tubulin polymerization by binding tubulin at a site distinct from vinblastine. In addition, cells resistant to vinblastine because of overexpression of P-glycoprotein remained fully sensitive to flubendazole, indicating that flubendazole can overcome some forms of vinblastine resistance. Given the different mechanisms of action, we evaluated the combination of flubendazole and vinblastine in vitro and in vivo. Flubendazole synergized with vinblastine to reduce the viability of OCI-AML2 cells. In addition, combinations of flubendazole with vinblastine or vincristine in a leukemia xenograft model delayed tumor growth more than either drug alone. Therefore, flubendazole is a novel microtubule inhibitor that displays preclinical activity in leukemia and myeloma.

AbstractSome patients with B-cell non-Hodkin lymphoma Lymphoma (NHL) become refractory to rituximab (anti-CD20 antibody) therapy associated with chemotherapy. Here, the effect of the anti-CD37 antibody-radionuclide conjugate lutetium-177 (177Lu)-lilotomab (Betalutin®) was investigated in preclinical models of NHL. In SCID mice bearing DOHH2 (transformed follicular lymphoma, FL) cell xenografts, 177Lu-lilotomab significantly delayed tumor growth, even at low activity (100 MBq/kg). In athymic mice bearing OCI-Ly8 (diffuse large B-cell lymphoma, DLBCL) or Ramos (Burkitt’s lymphoma) cell xenografts, 177Lu-lilotomab activity had to be increased to 500 MBq/kg to show a significant tumor growth delay. Clonogenic and proliferation assays showed that DOHH2 cells were highly sensitive to 177Lu-lilotomab, while Ramos cells were the least sensitive, and U2932 (DLBCL), OCI-Ly8, and Rec-1 (mantle cell lymphoma) cells displayed intermediate sensitivity. The strong 177Lu-lilotomab cytotoxicity observed in DOHH2 cells correlated with reduced G2/M cell cycle arrest, lower WEE-1- and MYT-1-mediated phosphorylation of cyclin-dependent kinase-1 (CDK1), and higher apoptosis. In agreement, 177Lu-lilotomab efficacy in vitro, in vivo, and in patient samples was increased when combined with G2/M cell cycle arrest inhibitors (MK-1775 and PD-166285). These results indicate that 177Lu-lilotomab is particularly efficient in treating tumors with reduced inhibitory CDK1 phosphorylation, such as transformed FL.

Recently, studies on connecting distributed generation (DG) to power distribution systems through DC links have been actively conducted. When a fault in feeder of this power distribution system occurs, a voltage dip can happen in the grid. In order to prevent voltage dips, there are several solutions such as the application of a superconducting fault current limiter (SFCL). If a SFCL with a larger impedance is applied, the voltage dip of the grid is effectively prevented. However, this action can bring about the malfunction or the delayed operation of the over-current relay (OCR) due to the decreased fault current, which causes another problem of protection coordination between the protective relays. On the other hand, if the impedance of the SFCL is too low, excessive reactive power is supplied by the fault ride-through (FRT) regulation and the active power is reduced. This causes an active power imbalance on the DC link and increases the DC link’s voltage. As previous solutions to prevent the rise of DC links’ voltage, the deloading method and the application of a chopper resistor have been suggested. In this paper, a technique called active power tracking control (APTC), was proposed to suppress the rise of DC links’ voltage. Case studies considering the impedance of SFCL in the constructed power distribution system were carried out, and the rise of DC links’ voltage could be effectively suppressed without any significant delay in the operation of the OCR. This study is expected to solve both the voltage dip of the grid and the rise of DC links’ voltage when distributed generation is connected to a grid.

Glutamate excitotoxicity is involved in the pathogenesis of many disorders, including stroke, traumatic brain injury, and Alzheimer’s disease, for which central insulin resistance is a comorbid condition. Neurotoxicity of glutamate (Glu) is primarily associated with hyperactivation of the ionotropic N-methyl-D-aspartate receptors (NMDARs), causing a sustained increase in intracellular free calcium concentration ([Ca2+]i) and synchronous mitochondrial depolarization and an increase in intracellular superoxide anion radical (O2–•) production. Recently, we found that insulin protects neurons against excitotoxicity by decreasing the delayed calcium deregulation (DCD). However, the role of insulin in O2–• production in excitotoxicity still needs to be clarified. The present study aims to investigate insulin’s effects on glutamate-evoked O2–• generation and DCD using the fluorescent indicators dihydroethidium, MitoSOX Red, and Fura-FF in cortical neurons. We found a linear correlation between [Ca2+]i and [O2–•] in primary cultures of the rat neuron exposed to Glu, with insulin significantly reducing the production of intracellular and mitochondrial O2–• in the primary cultures of the rat neuron. MK 801, an inhibitor of NMDAR-gated Ca2+ influx, completely abrogated the glutamate effects in both the presence and absence of insulin. In experiments in sister cultures, insulin diminished neuronal death and O2 consumption rate (OCR).

Abstract Abstract 3240 Poster Board III-177 Lymphomas are heterogeneous diseases comprising multiple clinical and biological subgroups. Several studies have shown that genomic instability and constitutive activation of the NF-kB pathway are key features for lymphoma development (Shen M,Hematologica 2007). However, it remains unclear whether changes in activation of the canonical and non-canonical NF-kB pathways (rel-A/p50 and rel-B/p52, respectively) reflect a response to genomic instability and therefore promotes lymphomagenesis. To answer this question, we first demonstrated in two lymphoma cell lines (Daudi and OCI-Ly3) that DNA damage induced by Doxorubicin (2 mcg/mL) resulted in nuclear localization of rel-A and Rel-B. Then, to determine the role of each NF-kB pathway in DNA repair and centrosome duplication we compared the number of cells positive for phospo-H2aX (pH2aX) and centrosomes numbers (measured by gamma-tubulin) in p105-siRNA (canonical) and P100-siRNA (non-canonical) with luciferase-siRNA (control) expressing cells. Our results showed that the expression of p105 and p100 siRNAs increase the number of pH2aX (+) cells compared to control. Subsequently, a time course measuring pH2aX (+) cells was performed after treating p105, P100 and luciferase siRNA OCI-ly3 expressing cell lines with Doxorubicin (2 mcg/mL). In cells expressing luciferase siRNA, pH2aX (+) cells peak (60%) at 60 minutes (min) and return to normal at 120 min, in p105 siRNA –cells pH2aX peak at 90 min (90% + cells) and then decrease similarly to luciferase siRNA cells. P100 siRNA cells demonstrate a continuous increased in pH2aX (+) cells up to 80%. In addition, p100 siRNA expression was associated with centrosome amplification (>2 centrosomes in 20-30% of the cells vs. < 8% in p105 or Luciferase siRNA expressing cells). Also, the expression of NF-kB siRNAs delayed doxorubicin-induced phosphorylation of p53 (serine 15 – target of ATM) and CHK2. To evaluate whether the genomic instability caused by both NF-kB siRNAs affects tumor development, we performed xenograft experiments. Our results demonstrated that NF-kB siRNAs not only slow down tumor initiation but prevented tumor development (p105 siRNA= 8 days delayed and 22% were tumor free and p100 siRNA= 13.5 days delayed and 55% were tumor free compared to luciferase siRNA). To investigate these findings in primary tissues we measured the number of phospo-H2aX (+) cells and the levels of rel-A and rel-B nuclear localization in 40 primary lymphoma tumor samples. Our results demonstrated that phospo-H2aX levels inversely correlated with rel-B nuclear localization (r=-0.58, p<0.0001). To identify possible explanations for these results, gene expression analysis was performed in cells expressing NF-kB siRNAs. Our results demonstrated that p105 siRNA regulated genes involved in DNA repair (PPP2R5C, ING5, SYF2, SYF2, XRCC6, etc) and p100 siRNA regulated genes involved in both DNA repair and centrosome duplication (GADD45 alpha, cyclin G, REDD1, PCBP4, etc) consistent with our results above. Quantitative PCR for some these genes during a doxorubicin-time course confirmed GADD45 alpha, cyclin G, PCBP4 and SFRS6 to be induced. We explored further the role of GADD45 alpha in lymphomas and found that knock down of this protein increase doxorubicin sensitivity by 50-fold. Overall this study demonstrated that activation of each NF-kB pathway is essential for maintaining genomic stability and therefore promoting tumor resistance to chemotherapy in lymphomas. In addition, we identified that GADD45 alpha is important target of the non-canonical NF-kB pathway for mediating genomic stability. These findings provide the rationale for designing novel agents aiming at targeting key genes involved in genomic stability. Disclosures No relevant conflicts of interest to declare.

Abstract We have recently shown that B-cell non Hodgkin’s lymphoma express the transcription factor PPARγ and undergo apoptosis upon exposure to PPARγ ligands. The synthetic triterpenoid CDDO is a specific ligand for PPARγ, and CDDO and its derivatives, CDDO-Im and DI-CDDO, induce diffuse large cell lymphoma (DLCL) death (OCI Ly10 and OCI Ly19 cells), with a potency of DI-CDDO&gt;CDDO-Im&gt;CDDO, suggesting that such agents have therapeutic potential in lymphoma. The natural PPARγ ligand, 15d-PGJ2 (which also elicits DLCL death), has previously been shown to inhibit mitochondrial complex I, enhance mitochondrial reactive oxygen species (ROS) generation, and react with protein thiols. Given that CDDO is structurally similar to 15d-PGJ2 we hypothesized that CDDO-induced cell death may similarly be mediated via complex I inhibition, ROS generation, thiol oxidation, and opening of a large membrane pore complex in the mitochondrial membrane, termed the “permeability transition” (PT) pore. Studies on isolated rat liver mitochondria however showed that none of the CDDO-derivatives inhibited complex I activity or affected mitochondrial protein thiols. However, all three compounds did induce PT pore opening and mitochondrial swelling, with a concurrent loss of mitochondrial membrane potential, in a Ca2+ dependent manner (potency DI-CDDO&gt;CDDO-Im&gt;CDDO). This is consistent with a previously shown role for Ca2+ in CDDO-induced cell death. Interestingly, this mitochondrial swelling was not inhibited by the classical PT pore inhibitor cyclosporin A (CsA). This is supported by our findings that the induction of OCI-Ly19 cell death by CDDO was also not inhibited by CsA, or by another classical PT pore inhibitor, nortriptyline. These phenomena may be partially explained by invoking the “unregulated PT pore”. In addition to the classical PT pore, a non-CsA sensitive “unregulated PT pore” also exists, which is generated by the aggregation of misfolded mitochondrial membrane proteins that are induced by oxidants and thiol reactive agents. That exposure of mitochondria to CDDO results in the formation of “unregulated PT pores” is supported by our findings that the proteosome inhibitor PS341, potentiates CDDO-induced cell death, suggesting the involvement of a protein folding response. The temporal role of ROS in CDDO-induced cell death was also investigated, and it was found that the antioxidant N-acetyl-cysteine did not inhibit PT pore opening, but did inhibit cell death. This is consistent with our observation that ROS generation in isolated mitochondria was not immediately triggered by CDDO, but rather increased at delayed time points, placing it downstream of PT pore opening. This proposes the following novel model of a direct mitochondrial effect of CDDO and its derivatives: \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \[CDDO{\rightarrow}\ mitochondrial\ protein\ misfolding\ {\rightarrow}\ unregulated\ PT\ pore\ formation\ {\rightarrow}\ ROS\ {\rightarrow}\ cell\ death\] \end{document} In summary: CDDO and its derivatives have direct effects on mitochondria, and represent novel therapeutic approaches for the treatment of patients with DLCL; and combinations of CDDO and its derivatives with proteosome inhibitors represent a rational combination to test in the context of clinical trials.

Acute myeloid leukemia (AML) is initiated and maintained by a relatively rare leukemia stem cells (LSCs) capable of self-renewal and proliferation. Recent data showed that LSCs (Lagadinou et al. Cell Stem Cell 2013) and residual cytarabine (Ara-C)-resistant AML cells (representing minimal residual disease, MRD) (Farge et al. Cancer Discovery 2017) are highly dependent on mitochondrial function for survival. This unique metabolic biology makes chemoresistant LSCs and AML cells vulnerable to pharmacological blockade of the oxidative phosphorylation (OXPHOS). We have reported that a novel OXPHOS inhibitor IACS-010759 potently inhibits mitochondrial complex I, suppresses OXPHOS and selectively inhibits the growth of AML cells in vitro and in vivo (Molina et al. Nat Med 2018). In this study, we aimed to determine the effects of OXPHOS inhibition with IACS-010759 on residual AML cells surviving standard chemotherapy (Doxorubicin/Ara-C, DA) in cell line and patient-derived xenograft (PDX) AML models. Consistent with our hypothesis, OCI-AML3 cells treated with DA in vitro induced elevated levels of reactive oxygen species, higher mitochondrial mass and membrane potential (Fig. 1A), indicating reliance on the mitochondrial metabolism. Further, Ara-C treatment resulted in significantly increased basal and maximal oxygen consumption rates (OCR) (36%±8%, p=0.03; 36%±3%, p=0.003, respectively) compared to control. In turn, targeting OXPHOS with IACS-010759 at 30 nM fully inhibited basal and Ara-C-induced OCR. These findings indicate that chemotherapy fosters mitochondrial respiration in AML, which could be abrogated by OXPHOS inhibitor. To test the efficacy of combining IACS-010759 (5 mg/kg) and standard chemotherapy (Doxorubicin: 1.5 mg/kg; Ara-C: 50 mg/kg) in vivo, we injected NRG mice with genetically engineered OCI-AML3/Luc/GFP cells. Bioluminescent imaging demonstrated significantly reduced leukemia burden in DA/IACS-010759 combination group compared to vehicle on days 15 and 42 (p<0.01) (Fig. 1B). DA/IACS-010759 combination significantly extended survival, compared to the vehicle or single-agent treatment arms (Fig. 1C). Mouse body weight monitoring indicated that therapy was well tolerated We next examined the efficacy of IACS-010759 on leukemia cells surviving chemotherapy in a chemosensitive PDX AML model of minimal residual disease (Fig. 1D). Treatment of mice inoculated with a human AML PDX harboring FLT3-ITD mutation with DA reduced circulating leukemia burden (0.8 ± 0.6% vs 45.8 ± 8.2% blasts in vehicle-treated mice, p=0.001). The residual AML cells in DA-treated mice expanded and caused rapidly progressive leukemia (78.2 ± 6.2% vs 95.3 ± 1.0% in vehicle-treated mice, p=0.047) on week 6 post DA. Daily oral treatment of mice with IACS-010759 (7.5 mg/kg) as a single agent reduced leukemia burden, and delayed leukemia recurrence when administered post completion of DA (Fig. 1E). A SPADE tree was built based on 13 surface markers and colored by expression intensity of CD34 using CyTOF mass cytometry data (Fig. 1F). The data demonstrated reduced frequency of CD34+CD38lowCD123+ AML LSCs and increase in CD11c+ differentiated cells in both IACS and IACS/DA groups (Fig. 1G&H). In contrast, chemotherapy alone failed to significantly reduce fractions of LSCs or induce differentiation. Proliferation measured by Ki67 was greatly reduced by IACS/DA combination in all populations including LSCs (1.4 ± 0.3% vs 5.5 ± 0.4% in vehicle group, p<0.01). The expression of Hypoxia-Inducible Factor 1α (HIF-1α) was downregulated, consistent with the decreased oxygen consumption induced by IACS-010759 (not shown). In conclusion, minimal residual AML cells surviving chemotherapy depend on OXPHOS for survival. OXPHOS inhibition with complex I inhibitor IACS-010759 is effective in reducing LSCs and MRD, alone and in combination with chemotherapy in vivo. Our data advocate for combining IACS-010759 with chemotherapy for improved control of MRD upon identification of a recommended Phase II dose in a clinical trial of IACS-010759 in AML (NCT02882321). Disclosures Zhang: The University of Texas M.D.Anderson Cancer Center: Employment. Kuruvilla:The University of Texas M.D.Anderson Cancer Center: Employment. Kantarjian:Pfizer: Honoraria, Research Funding; Cyclacel: Research Funding; AbbVie: Honoraria, Research Funding; Daiichi-Sankyo: Research Funding; Immunogen: Research Funding; Actinium: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria; Ariad: Research Funding; Novartis: Research Funding; Agios: Honoraria, Research Funding; BMS: Research Funding; Astex: Research Funding; Amgen: Honoraria, Research Funding; Jazz Pharma: Research Funding. Daver:Jazz: Consultancy; Hanmi Pharm Co., Ltd.: Research Funding; Agios: Consultancy; Immunogen: Consultancy, Research Funding; Genentech: Consultancy, Research Funding; BMS: Consultancy, Research Funding; Celgene: Consultancy; Karyopharm: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Daiichi Sankyo: Consultancy, Research Funding; Sunesis: Consultancy, Research Funding; Forty-Seven: Consultancy; Novartis: Consultancy, Research Funding; Incyte: Consultancy, Research Funding; Abbvie: Consultancy, Research Funding; Astellas: Consultancy; Servier: Research Funding; NOHLA: Research Funding; Glycomimetics: Research Funding; Otsuka: Consultancy. Andreeff:BiolineRx: Membership on an entity's Board of Directors or advisory committees; CLL Foundation: Membership on an entity's Board of Directors or advisory committees; Leukemia Lymphoma Society: Membership on an entity's Board of Directors or advisory committees; NCI-RDCRN (Rare Disease Cliln Network): Membership on an entity's Board of Directors or advisory committees; German Research Council: Membership on an entity's Board of Directors or advisory committees; NCI-CTEP: Membership on an entity's Board of Directors or advisory committees; Cancer UK: Membership on an entity's Board of Directors or advisory committees; Center for Drug Research & Development: Membership on an entity's Board of Directors or advisory committees; NIH/NCI: Research Funding; CPRIT: Research Funding; Breast Cancer Research Foundation: Research Funding; Oncolyze: Equity Ownership; Oncoceutics: Equity Ownership; Senti Bio: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Eutropics: Equity Ownership; Aptose: Equity Ownership; Reata: Equity Ownership; 6 Dimensions Capital: Consultancy; AstaZeneca: Consultancy; Daiichi Sankyo, Inc.: Consultancy, Patents & Royalties: Patents licensed, royalty bearing, Research Funding; Jazz Pharmaceuticals: Consultancy; Celgene: Consultancy; Amgen: Consultancy. Konopleva:Calithera: Research Funding; Stemline Therapeutics: Consultancy, Honoraria, Research Funding; Forty-Seven: Consultancy, Honoraria; Eli Lilly: Research Funding; AbbVie: Consultancy, Honoraria, Research Funding; Cellectis: Research Funding; Amgen: Consultancy, Honoraria; F. Hoffman La-Roche: Consultancy, Honoraria, Research Funding; Genentech: Honoraria, Research Funding; Ascentage: Research Funding; Kisoji: Consultancy, Honoraria; Reata Pharmaceuticals: Equity Ownership, Patents & Royalties; Ablynx: Research Funding; Astra Zeneca: Research Funding; Agios: Research Funding.