Activating mutations in FMS-like tyrosine kinase 3 (FLT3) are common in acute myeloid leukemia (AML) and drive leukemic cell growth and survival. Although FLT3 inhibitors have shown considerable promise for the treatment of AML, they ultimately fail to achieve long-term remissions as monotherapy. To identify genetic targets that can sensitize AML cells to killing by FLT3 inhibitors, we performed a genome-wide RNA interference (RNAi)-based screen that identified ATM (ataxia telangiectasia mutated) as being synthetic lethal with FLT3 inhibitor therapy. We found that inactivating ATM or its downstream effector glucose 6-phosphate dehydrogenase (G6PD) sensitizes AML cells to FLT3 inhibitor induced apoptosis. Examination of the cellular metabolome showed that FLT3 inhibition by itself causes profound alterations in central carbon metabolism, resulting in impaired production of the antioxidant factor glutathione, which was further impaired by ATM or G6PD inactivation. Moreover, FLT3 inhibition elicited severe mitochondrial oxidative stress that is causative in apoptosis and is exacerbated by ATM/G6PD inhibition. The use of an agent that intensifies mitochondrial oxidative stress in combination with a FLT3 inhibitor augmented elimination of AML cells in vitro and in vivo, revealing a therapeutic strategy for the improved treatment of FLT3 mutated AML.A cute myeloid leukemia (AML) is a hematological cancer that is characterized by the aberrant growth of myeloid progenitor cells with a block in cellular differentiation. AML is the most common adult acute leukemia and accounts for ∼20% of childhood leukemias. Although frontline treatment of AML with cytotoxic chemotherapy achieves high remission rates, 75-80% of patients will either not respond to or will relapse after initial therapy, and most patients will die of their disease (1, 2). Thus, more effective and less toxic therapies for AML are required. The promise of molecularly targeted cancer therapies has generated much excitement with the remarkable clinical success of the small molecule tyrosine kinase inhibitors (TKIs) targeting the oncogenic kinase BCR-ABL for the treatment of chronic myeloid leukemia (3). However, targeted approaches for the treatment of AML have not yet yielded major successes.In AML, aberrant signal transduction drives the proliferation and survival of leukemic cells. Activated signal transduction occurs through genetic alterations of signaling molecules such as FLT3, KIT, PTPN11, and members of the RAS family (4, 5). Given the successful development and utilization of numerous TKIs, the FLT3 receptor tyrosine kinase has emerged as a promising target for the treatment of AML. Indeed, activating mutations in FLT3 are one of the most frequently observed genetic defects in AML and are comprised predominantly of internal tandem duplication (ITD) mutations in the juxtamembrane domain (6). FLT3-ITD mutations are associated with poor prognosis, including increased relapse rate, decreased disease-free survival, and poor overall survival (5,7,8). The cl...

Purpose Although tyrosine kinase inhibitors (TKI) can be effective therapies for leukemia, they fail to fully eliminate leukemic cells and achieve durable remissions for many patients with advanced BCR-ABL+ leukemias or acute myeloid leukemias (AML). Through a large-scale synthetic lethal RNAi screen, we identified pyruvate dehydrogenase, the limiting enzyme for pyruvate entry into the mitochondrial tricarboxylic acid cycle, as critical for the survival of chronic myeloid leukemia cells upon BCR-ABL inhibition. Here we examined the role of mitochondrial metabolism in the survival of Ph+ leukemia and AML upon TK inhibition. Experimental Design Ph+ cancer cell lines, AML cell lines, leukemia xenografts, cord blood, patient samples were examined. Results We showed that the mitochondrial ATP-synthase inhibitor oligomycin-A greatly sensitized leukemia cells to TKI in vitro. Surprisingly, oligomycin-A sensitized leukemia cells to BCR-ABL inhibition at concentrations 100–1000-fold below those required for inhibition of respiration. Oligomycin-A treatment rapidly led to mitochondrial membrane depolarization and reduced ATP levels, and promoted superoxide production and leukemia cell apoptosis when combined with TKI. Importantly, oligomycin-A enhanced elimination of BCR-ABL+ leukemia cells by TKI in a mouse model and in primary blast crisis CML samples. Moreover, oligomycin-A also greatly potentiated the elimination of FLT3-dependent AML cells when combined with a FLT3 TKI, both in vitro and in vivo. Conclusions TKI therapy in leukemia cells creates a novel metabolic state that is highly sensitive to particular mitochondrial perturbations. Targeting mitochondrial metabolism as an adjuvant therapy could therefore improve therapeutic responses to TKI for patients with BCR-ABL+ and FLT3ITD leukemias.

Aim: To study the efficacy of intravenous vitamin C in management of moderate and severe COVID-19. Objective: To determine the efficacy of intravenous vitamin C in reducing in-hospital mortality in moderate and severe cases of COVID-19. Design: Parallel, double-blinded randomized controlled trial with placebo. Ethical clearance was obtained from the institutional ethics committee, AIIMS Patna. The trial was registered with the Clinical Trials Registry – India (registration number- CTRI/2020/11/029230.) Setting: A tertiary care centre in Bihar, India Participants: All patients above the age of 18 years both males and females, admitted in ICU with a diagnosis of moderate and severe COVID-19 (on the basis of a positive reverse transcriptase polymerase chain reaction (RT–PCR) report) at our facility during the study period (01/10/2020–31/12/2020) not having any of the exclusion criteria. Intervention: The patients in the intervention arm were given 1 gram (2 ampoules of 2 ml each containing 500 mg of vitamin C mixed in 100 ml normal saline) intravenous vitamin C 8 hourly for four days. The patients in the placebo arm received similar looking ampoules (2 ampoules of 2 ml sterile water for injection mixed in 100 ml normal saline) intravenously 8 hourly for four days. The rest of the treatment was given as per the standard operating procedure (SOP) of the institute with adjustments as per treating team’s judgement. Outcome Measures: Primary outcome was reduction in in-hospital mortality. Secondary outcomes were improvement in qSOFA score, pO2/fiO2 ratio, fall in inflammatory markers, need for mechanical ventilation and vasopressors. Results: Regarding primary outcome, 10 (33.3%) patients died in intervention group compared to 13 (43.3%) in placebo. Worth noting from baseline characteristics is that 86.7% in intervention arm were of severe category compared to 66.7% severe category patients in placebo group. Though number of severe cases were more in intervention arm there has been comparatively less mortality in this group. Regarding secondary outcomes, amongst 30 patients in vitamin C group, 11 (36.7%) required invasive mechanical ventilation compared to 14 (46.7%) out of 30 in placebo group but the difference was not statistically significant. Although there were a greater number of moderate cases in placebo group, invasive ventilation requirement (and NIV requirement) was more in this group, thus it could be considered that vitamin C might have a role in reducing the severity of disease. The need for vasopressor therapy was higher in intervention arm 33.3% compared to 26.7% in placebo but not significant statistically. The secondary outcomes of the study such as improvement in organ failure score (qSOFA Score), fall in level of inflammatory markers, improvement in respiratory index (pO2/fiO2 ratio), need...

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: To overcome ever increasing cases of antifungal resistance and circumventing side effects and drug interactions related with currently available drugs has impelled the need to expedite the process of drug discovery and development of novel antifungals. 1,4-Disubstituted 1,2,3-triazole has gained tremendous interest in last two decades mainly because of its ease of synthesis via copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) and its broad spectrum of chemotherapeutic potential. 1,2,3-Triazole is an excellent pharmacophore which has been used as a bioisostere for obtaining libraries of new medicinally important scaffolds. The present review focus on the recent advances (2016-2021) of 1,2,3-triazole derivatives obtained by CuAAC as potential antifungal agents that may facilitate triazole based antifungal development process.