The 5-year survival rate for late-stage metastatic melanoma is only ~30%. A major reason for this low survival rate is that one of the most commonly mutated genes in melanoma, NRAS, has no FDA-approved targeted therapies. Because the RAS protein does not have any targeted therapies, patients with RAS mutant tumors have an ongoing need for treatments that indirectly target RAS. This thesis project aims to identify expression and phosphorylation levels of proteins downstream of RAS in melanoma cell lines with the most common driver mutations. By analyzing the protein-level differences between these genetic mutants, we hope to identify additional indirect RAS protein targets for the treatment of NRAS mutant melanoma. RAS has several downstream effector proteins involved in oncogenic signaling pathways including FAK, Paxillin, AKT, and ERK. 5 melanoma cell lines (2 BRAF mutant, 2 NRAS mutant, and 1 designated wildtype) were analyzed using western bloting for FAK, Paxillin, AKT, and ERK phosphorylation and total expression levels. The results of western blot analysis showed that NRAS mutant cell lines had increased expression of phosphorylated Paxillin. Increased Paxillin phosphorylation corresponds to increased Paxillin binding at the FAT domain of FAK. Therefore, cell lines with increased FAK FAT – Paxillin interaction would be more sensitive to FAK FAT domain inhibition. The data presented provide an an explanation for the reduction in cell viability in NRAS mutant cell lines infected with Ad-FRNK. This information also has significant clinical relevance as researchers work to develop synthetic FAK FAT domain inhibitors, such as cyclic peptides. Additionally, cell lines with high levels of phosphorylated AKT showed a significant reduction in the amount of phosphorylated ERK. The identification of this inverse relationship may help to explain why BRAF and NRAS mutations are mutually exclusive. To conclude, NRAS mutant cell lines have increased expression of phosphorylated Paxillin and AKT which may explain why NRAS mutant cell lines are more sensitive to FAK FAT domain inhibition.

Annually approximately 1.5 million Americans suffer from a traumatic brain injury (TBI) increasing the risk of developing a further neurological complication later in life [1-3]. The molecular drivers of the subsequent ensuing pathologies after the initial injury event are vast and include signaling processes that may contribute to neurodegenerative diseases such as Alzheimer’s Disease (AD). One such molecular signaling pathway that may link TBI to AD is necroptosis. Necroptosis is an atypical mode of cell death compared with traditional apoptosis, both of which have been demonstrated to be present post-TBI [4-6]. Necroptosis is initiated by tissue necrosis factor (TNF) signaling through the RIPK1/RIPK3/MLKL pathway, leading to cell failure and subsequent death. Prior studies in rodent TBI models report necroptotic activity acutely after injury, within 48 hours. Here, the study objective was to recapitulate prior data and characterize MLKL and RIPK1 cortical expression post-TBI with our lab’s controlled cortical impact mouse model. Using standard immunohistochemistry approaches, it was determined that the tissue sections acquired by prior lab members were of poor quality to conduct robust MLKL and RIPK1 immunostaining assessment. Therefore, the thesis focused on presenting the staining method completed. The discussion also expanded on expected results from these studies regarding the spatial distribution necroptotic signaling in this TBI model.