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Gadewal, N.

Publications and source records attributed to Gadewal, N..

2 recordsLinked to original sources

Mitocurcumin mediated redox disruption and metabolic rewiring induces tumor regression in Drosophila intestinal stem cell tumors

Mitochondria-targeted modulation of redox homeostasis has emerged as a promising strategy for controlling pathological cell proliferation. Here, we investigate the effects of Mitocurcumin in a Yorkie-driven intestinal stem cell tumor model in Drosophila. Using an integrative, genetically tractable approach combining in silico molecular modelling with in vivo functional analyses, we identify thioredoxin reductase (TrxR) as a conserved redox-associated target of Mitocurcumin. Docking and molecular dynamics simulations predict a stable interaction of Mitocurcumin with both Drosophila and mammalian TrxR homologs. Functionally, Mitocurcumin treatment reduces mitotic activity, elevates reactive oxygen species (ROS) selectively within escargot-positive intestinal stem cell population, enhances apoptosis in the tumor-bearing guts, and causes significant mitochondrial membrane depolarization. These cellular effects coincide with dose-dependent regression of Yorkie-induced intestinal hyperplasia. Despite mitochondrial functional impairment, mitochondrial morphology remains largely preserved, suggesting primary disruption of redox buffering rather than structural collapse. Metabolomic profiling of these guts further reveals remodelling of energy metabolism consistent with adaptive responses to oxidative stress. Importantly, Mitocurcumin alleviates tumor-associated organismal bloating and significantly extends lifespan indicating a previously uncharacterized systemic, organism-wide response to Mitocurcumin treatment in an in vivo scenario. Collectively, our findings establish TrxR-mediated redox regulation as a critical vulnerability in Yorkie-driven hyperproliferation and highlight the utility of Drosophila as an integrative in vivo platform for evaluating mitochondria-targeted bioactive molecules.

cancer biology↗

Medulloblastoma-associated DDX3X mutants are oncogenic having a defect in translation-promoting activity but functional in stress granule formation and interferon signaling

DDX3X, a DEAD box-containing RNA helicase, is known to play diverse roles in RNA metabolism, stress response, innate immunity, and cancer. Medulloblastoma is the single most common malignant brain tumor in children. DDX3X is recurrently mutated in the WNT and SHH subgroups of medulloblastoma. CRISPR-Cas9 mediated DDX3X knockout was successful in the HEK293FT cells but generated only non-truncating indels in the medulloblastoma cells suggesting DDX3X is necessary for the viability of the cells. Downregulation of DDX3X expression using shRNA also brought about a considerable reduction in proliferation, clonogenic potential, and anchorage-independent growth of the medulloblastoma cells. Thus, DDX3X expression was found to be essential for the survival, growth, and malignant potential of the medulloblastoma cells consistent with the non-truncating nature of medulloblastoma-associated DDX3X mutations. The medulloblastoma-associated DDX3X mutants were found to be defective in their ability to drive the translation of mRNAs with complex 5-UTR that is dependent on the ATP-dependent helicase activity of DDX3X. These helicase defective DDX3X mutants could restore the expression of interferon signaling genes and malignant potential lost upon DDX3X knockdown in medulloblastoma cells. Their N-terminal domain is intact and was found to be functional in stress granule formation. DDX3X mutants upregulated expression of malignancy-related genes suggesting tumor suppressive role for the helicase activity in the medulloblastoma pathogenesis. Inhibitors of the N-terminal domain of DDX3X which is essential for the viability of medulloblastoma cells could have therapeutic potential in the treatment of WNT and SHH subgroup medulloblastomas.

cancer biology↗