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Biology subjects

Yung, M.

Publications and source records attributed to Yung, M..

2 recordsLinked to original sources

Purinergic signaling promotes gliomagenesis through nuclear calcium transients

Intracellular Ca2+ transients drive key developmental and physiological processes, yet their role in oncogenesis remains incompletely understood. In glioblastoma (GBM), an aggressive brain malignancy, tumor cellular networks exhibit self-sustaining Ca2+ transients that promote tumor growth through unclear mechanisms. Using patient-derived GBM models, we show that these transients depend primarily on intracellular Ca2+ stores and extend to the nucleus to drive tumorigenesis. A neuromodulator screen identified extracellular purines ATP and ADP as potent inducers of both nuclear and cytosolic Ca2+ transients via activation of metabotropic purinergic P2RY1 receptors, whose knockdown attenuates tumorigenicity in vitro and in vivo. Mechanistically, Ca2+ transients promote tumorigenesis via the nuclear Ca2+/calmodulin-dependent kinase CAMK4, which regulates transcriptional and epigenetic programs, as well as ribosomal DNA transcription. From the therapeutic perspective, pharmacologic P2RY1 inhibition suppresses tumor growth in vitro and in vivo. Collectively, these findings reveal a pharmacologically targetable oncogenic mechanism in GBM and possibly other malignancies.

cancer biology↗

μ-Opioid Endomorphins and DDP-IV Inhibitor SitagliptinEnhance Amyloid-Beta Clearance and Memory in anAlzheimer's Cell Model

Alzheimers Disease is a neurodegenerative disorder caused by A{beta}42 aggregation. Endomorphins 1 and 2 (EM1, EM2), two novel -opioid agonists, have been implicated in protecting against A{beta}42 toxicity, though it is unclear how the endomorphins achieve their effects. Phase one of the study found that EM1 and EM2 activation protected A{beta}42-treated cells. This protection, mediated by -opioid receptor (MOR) activation, also reduced rotenone-induced oxidative stress, both in a dose-dependent manner. Pretreatment with naloxone, a -opioid antagonist, reversed these effects, confirming MOR involvement in EM1 and EM2s actions. In phase two, molecular docking techniques suggested that sitagliptin can prevent intracellular EM1 degradation. In vitro assays demonstrated that sitagliptin enhanced intracellular EM1s beneficial effects in promoting cell survival and reducing cell apoptotic activity, A{beta}42 aggregation, and hydrogen peroxide free radical concentrations. This suggests intracellular EM1 can mitigate the toxic effects of A{beta}42 aggregation. However, sitagliptin did not enhance EM1s effects on BDNF expression or neurite outgrowth, suggesting that MOR activation, rather than intracellular EM1, primarily drives mechanisms associated with memory improvement. Collectively, our findings suggest that both intracellular EM1 and EM1-mediated MOR activation offer potential therapeutic avenues for mitigating memory impairment in Alzheimers and potentially COVID-19. Furthermore, this research underscores the critical role of the MOR in broader memory mechanisms.

neuroscience↗