Saudi Cultural Missions Theses & Dissertations
Permanent URI for this communityhttps://drepo.sdl.edu.sa/handle/20.500.14154/10
Browse
2 results
Search Results
Item Restricted ANALYZING THE ROLE OF MDMX COMPARED TO MDM2 IN REGULATING CELL DEATH IN PROSTATE CANCER CELLS(Nova Southeastern University, 2024-07) Alsarrani, Ahmed; Rathinavelu, AppuProstate cancer is the most prominent cancer type and the second leading cause of cancer death among men in the USA. In this study, we evaluated the role of MDMX compared to MDM2, the two proto-oncogenes involved in the negative regulation of p53, in causing cell death and cell cycle arrest through p53 dependent and independent mechanisms. We observed that inhibition of MDMX decreased the cell viability of LNCaP prostate cancer cells in response to treatments with both NSC (NSC-207895) and SJ (SJ-172550), which are MDMX specific inhibitors. MDMX inhibition appears to induce necroptosis in LNCaP and PC3 prostate cancer cells by elevating the expression of receptor-interacting protein kinase 1 and receptor-interacting protein kinase 3 (RIP1 and pRIP3) and phosphor-mixed lineage kinase domain-like protein (pMLKL), which are key elements of the necroptotic pathway. These data were consistent with fluorescence images that were obtained using SYTOX® Green which is specific for detecting cells that undergo programmed or other forms of cell death. Moreover, the fluorescence images using DEVD staining, which is a fluorogenic substrate that can bind to caspases 3/7 during apoptosis, revealed that MDM2 inhibition by RG-7388 induced apoptosis through caspase activation. To further confirm the effects of MDMX on cell migration, NSC effectively blocked the cancer cell migration in LNCaP, not PC3 cells during the scratch assay. However, RG-7388 didn’t have a significant effect on cell migration but mainly caused cell death. Moreover, MDM2 inhibition by RG-7388 increases the expression of p21 and induces PARP cleavage, which highlights its role in cell cycle arrest and apoptosis. Analysis of the miRNA has revealed that inhibition of MDMX and MDM2 can significantly upregulate hsa-let-7d-5p, hsa-let- 7g-5p, hsa-miR-15a-5p, and hsa-miR-106b-5p levels, which have tumor suppressor characteristics. Furthermore, oncogenic miRNAs (OncomiRs) such as hsa-miR-10a-5p and hsa-miR-30b-5p were downregulated, which is in favor of the cell cycle arrest and cell death. The overall outcomes of our experiments provide additional knowledge and strategies for making an accurate assessment of the most suitable therapeutic strategies for achieving effective treatments for MDMX-positive prostate cancer.21 0Item Restricted PROTEOMICS ANALYSIS OF RNA BINDING PROTEINS IN PROSTATE CANCER CELLS(Clark Atlanta University, 2024-03-26) Dwaed, Abdulrahman; Cinar, BekirRNA-binding proteins (RBPs) govern various RNA-related functions, and dysregulation of RBPs is linked to numerous human diseases, including cancer. RBPs regulate the intricate facets of RNA biogenesis, impacting its metabolism and functional kinetics. This study investigates the biochemical and functional interactions between the RNA-binding protein NPM1 and the Hippo pathway effector of the transcriptional coregulatory protein YAP1. This study also examined the system-wide changes in RBP patterns in prostate cancer cell lines with differential responses to androgen hormone signaling. This study revealed that androgen hormone signaling regulates the protein-protein interaction of YAP1 with NPM1. GST-pulldown assay combined with western blot showed that the proline-rich region and WW/SH3 domain of YAP1 mediated the interaction with NPM1. The proximity ligation assay combined with co-immunoprecipitation further verified the interaction between YAP1 and NPM1 in the androgen-dependent (AD) and androgen-independent (AI) cell lines. Disruption of NPM1 activity by genetic and pharmacological approaches reduced cell growth and cell migration in cultures, likely mediated by the inhibition of YAP1. Moreover, treatment of AD and AI cells with or without androgen resulted in distinct RBP patterns, as demonstrated by enhanced RNA interactome capture assay combined with quantitative mass spectroscopy-based proteomics. Furthermore, the analysis of prostate cancer tissues showed an elevated NPM1 expression that correlated with prostate tumor progression. These findings suggest that altered RBP patterns downstream of modified androgen hormone signaling contribute to tumor progression, and the YAP1-NPM1 axis may constitute a viable drug target in cancer.17 0