CSF Archives - The Graduate School’s Student Success program

9:25-9:45	Autumn Tucker Presentation Time: 9:25-9:45 Home University: UNC-Chapel Hill Research Mentor: Dr. Leon Coleman, Pharmacology Program: CSF, CSS Research Title: Persistent Effects of Alcohol Use on Alzheimer's Disease Tau Pathology Several epidemiological studies have found that heavy alcohol use may increase the risk of developing Alzheimer’s disease (AD), although the mechanisms behind this link are unclear. The increase in neuroinflammation seen during alcohol abuse and AD may drive this connection, however, the effects of heavy alcohol use on Alzheimer’s pathology during abstinence have not been explored. Additionally, the persistent effects of alcohol abuse on the sexual dimorphism of AD pathology remain to be explored. Triple transgenic AD mice models were treated with ethanol for three months during adulthood followed by five months of abstinence to model sustained recovery following heavy alcohol use until Alzheimer’s pathology begins to develop. By visualizing brain tissue via immunohistochemistry and analyzing cortical and hippocampal protein and gene expression through western blotting and RT-PCR, the sustained changes in AD pathology as a result of alcohol abuse were studied. The two pathological hallmarks of Alzheimer’s disease (amyloid plaques and tau tangles) were measured to directly analyze these conditions. Although there was not a persistent increase in amyloid plaques as a result of alcohol use, there was a persistent increase in phosphorylated tau in female subjects, particularly in the piriform cortex, which is known to be sensitive to alcohol. There is a correlation between the increase in phosphorylated tau with long-term changes in several genes known to play a role in immunoinflammatory responses.	Persistent Effects of Alcohol Use on Alzheimer's Disease Tau Pathology	CSF, CSS
3:10-3:30	Jasmine Jahad Presentation Time: 3:10-3:30 Home University: UNC-Chapel Hill Research Mentor: ManHua Zhu, Neuroscience Program: CSF Research Title: Electronic nicotine vapor exposure and central amygdala activity in mice Nicotine is a highly addictive chemical that has traditionally been consumed by smoking cigarettes. Due to the introduction of new technology such as electronic cigarettes, nicotine vaping has surged in popularity. The rising popularity of vaping necessitates the development of preclinical nicotine vapor exposure models in mice, as well as a better knowledge of the effects of vaping on certain brain regions. The central amygdala (CeA) is a brain region that regulates behavioral and emotional responses to stress or fear reactions. The cellular implications of nicotine vapor exposure on the CeA were investigated using a mouse model of electronic vapor exposure. Adult male C57BL/6J mice were given intermittent vapes of 120 mg/ml nicotine in propylene glycol: vegetable glycerol (PG/VG) or PG/VG control for a single 3-hour session (acute exposure) or 5 daily sessions (repeated exposure). Nicotine vapor exposure increased serum nicotine and cotinine levels in both acute and repeated exposures. Acute nicotine vapor exposure increased central amygdala (CeA) activity in individual neuronal firing as well as cFos expression, a molecular activity marker. Repeated exposure did not produce the same alterations in neuronal activity as acute exposure. This research validated a mouse model of nicotine vapor exposure and added to our understanding of how electronic nicotine vapor has varied effects on CeA neuronal activity.	Electronic nicotine vapor exposure and central amygdala activity in mice	CSF
3:35-3:55	Alexis Jean Morales Presentation Time: 3:35-3:55 Home University: UNC-Chapel Hill Research Mentor: Channing Der, Pharmacology Program: CSF Research Title: YAP1-TAZ-TEAD Inhibition Sensitizes Cells to KRASG12C Inhibition Mutations in the KRAS oncogene are among the most frequent driver events in human cancers. Following decades of failed efforts, KRAS was considered ‘undruggable’. However, recent efforts in covalently targeting KRAS mutants harboring a G12C mutation has produced the first anti-KRAS therapy to reach FDA approval. That said, acquired mechanisms of drug resistance are certain to limit the long-term effectiveness of G12C inhibition (G12Ci); something that has been reported in the clinic. As such, the search is on for effective strategies by which to sensitize cells to G12Ci. A currently undescribed, mechanism of resistance to G12Ci is the activation of the transcriptional co-activator paralogs, YAP1 and TAZ. Activation of YAP1 has been shown to overcome KRAS addiction in KRAS-mutant cancers. In concordance with these observations, we found that targeting both YAP1 and TAZ significantly sensitizes cells to MRTX1257, analog of the FDA-approved G12Ci MRTX849 (Mirati Therapeutics). As no YAP1/TAZ direct inhibitors exist, a TEAD1-4 dominant-negative construct was utilized to target the TEAD family of transcription factors, the canonical YAP1/TAZ transcriptional partners, as a mean to indirectly inhibit YAP/TAZ activity. We found that inhibition of TEAD1-4 transcriptional activity sensitized cells to G12Ci. We further examined the efficacy of combined TEAD and G12C inhibition using an array of TEAD inhibitors (Vivace Therapeutics) in combination with MRTX1257. This combination produced a highly synergistic reduction in cell viability.	YAP1-TAZ-TEAD Inhibition Sensitizes Cells to KRASG12C Inhibition	CSF
4:00-4:20	Kayla Snare Presentation Time: 4:00-4:20 Home University: UNC-Chapel Hill Research Mentor: Channing Der, Pharmacology Program: CSF Research Title: Validating gene targets of MYC transcriptional activity in pancreatic ductal adenocarcinoma Pancreatic ductal adenocarcinoma (PDAC) is the third deadliest cancer in the United States with a dismal 5-year survival rate of 10%. 97% of PDAC cases are driven by mutations in the KRAS oncogene, a GTPase that regulates a myriad of signaling cascades responsible for promoting cell growth, proliferation, and metabolism. When mutated, KRAS exists predominantly in its active, GTP-bound state, which allows it to constitutively signal to its downstream effectors and drive PDAC growth. One of the most notable signaling cascades activated by mutant KRAS is the RAF-MEK-ERK MAPK pathway, which has been the target of several small-molecule inhibitors. Unfortunately, resistance to these inhibitors arises quickly, possibly through KRAS-driven stabilization of the MYC transcription factor. MYC is a known oncogene in many cancer types, and its overexpression in PDAC has been well established. While effective pharmacologic inhibitors against members of the MAPK pathway exist, reliable MYC inhibitors have proven more elusive. A tool compound targeting MYC activity, 975, recently showed promising anti-tumor effects in prostate cancer mouse models, but has yet to be characterized in PDAC. Here, to gauge the effects of 975 on MYC activity in PDAC cells, target genes of MYC transcriptional activity were identified. Following acute suppression of MYC by siRNA knockdown, RNA-sequencing and subsequent qPCR analysis of PDAC cells indicated HSPD1, MYBBP1A, and CBL as candidate MYC-driven gene targets in PDAC.	Validating gene targets of MYC transcriptional activity in pancreatic ductal adenocarcinoma	CSF
4:00-4:20	Amber Amparo Presentation Time: 4:00-4:20 Home University: UNC-Chapel Hill Research Mentor: Channing Der, Ph.D., Pharmacology Program: CSF Research Title: Defining the Role of Mitochondrial Dynamics in Regulating PDAC Cell Sensitivity to ERK Inhibition Pancreatic ductal adenocarcinoma (PDAC) is driven by oncogenic activation of KRAS in over 95% of patients. Recent evidence suggests that mutant KRAS activation rewires cancer cell metabolism, altering mitochondrial morphology and function. Specifically, activation of the downstream RAF-MEK-ERK effector signaling pathway leads to phosphorylation of mitochondrial fission protein DRP1, which drives mitochondrial fragmentation to support PDAC growth. In contrast, pharmacological inhibition of ERK signaling, using selective ERK1/2 inhibitor (ERKi, SCH227984), causes mitochondrial fusion and inhibits PDAC cell growth. However, the mechanistic basis by which mitochondrial fission supports PDAC proliferation remains unknown. Furthermore, it is unclear whether mitochondrial fusion is required for ERKi-mediated growth suppression. We hypothesized that preventing mitochondrial fusion by silencing mitochondrial fusion proteins OPA1 and MFN1 will yield resistance to inhibition of ERK signaling. To test this, we used two unique siRNAs targeting OPA1 or MFN1, which caused a hyper-fragmented mitochondrial phenotype. Interestingly, we found that loss of mitochondrial fusion in Pa14C cells increased the GI50 concentration of ERKi by ~40% compared to control-treated cells. This suggests that PDAC cells with hyper-fragmented mitochondria may be slightly resistant to ERKi. However, the other PDAC cell line tested (HPAC) displayed, on average, no significant changes in the GI50 concentration of ERKi. Future studies are focused on further characterizing the impact of altered mitochondrial dynamics on PDAC cell sensitivity to inhibition of KRAS downstream effectors.	Defining the Role of Mitochondrial Dynamics in Regulating PDAC Cell Sensitivity to ERK Inhibition	CSF
4:25-4:45	Branna Campbell Presentation Time: 4:25-4:45 Home University: UNC-Greensboro Research Mentor: Henrik Dohlman, Department of Pharmacology Program: CSF Research Title: Detecting Activity of the Yeast Mating Pathway Through GFP MAPKs (mitogen-activated protein kinase) receive external stimuli to induce various cellular processes such as the cell cycle in eukaryotic cells. Higher order eukaryotic cells such as mammalian cells are more complex, making them harder to study. Thus we use the simple eukaryotic yeast cells as a model to study the MAPK pathway. In the yeast mating pathway, mating pheromone, α or a- factor, activates the MAPK cascade, Ste11, Ste7, and Fus3, that results in mating gene transcription. Depending on the amount of pheromone and the age of the yeast cells, the mating pathway activity levels change. We hypothesize that the mating pathway will become less responsive to mating pheromones as yeast age. To test our hypothesis, we transformed Fus1-GFP plasmid into the yeast cells in order to monitor the mating pathway activity levels upon pheromone induction. We then measure the GFP intensity of the cells which corresponds to the activity of the mating pathway. As a result, the information obtained from this study can be applied to other, more complex eukaryotic cells and also grant a better understanding of cellular mechanisms when considering how cells respond to medications and therapeutics.	Detecting Activity of the Yeast Mating Pathway Through GFP	CSF
4:25-4:45	Joshua Wynn Presentation Time: 4:25-4:45 Home University: UNC-Chapel Hill Research Mentor: Dr. Lee M. Graves, Pharmacology Program: CSF Research Title: Activation of Mitochondrial Protease ClpP Inhibits mTOR Activity in Triple Negative Breast Cancer ONC201 is an anti-cancer imipridone in clinical trials for multiple malignancies. Novel ONC201 analogues (the TR compounds) with greater potency were identified, although the anti-cancer mechanism of these drugs remained poorly understood. The Graves lab recently identified the mitochondrial caseinolytic protease (ClpP) as the target of these compounds and showed that ClpP activation was required for growth inhibition. Because the mTOR (mechanistic target of rapamycin) pathway plays a central role in regulating growth-related cellular processes including protein translation, nucleotide metabolism, and lipid synthesis, I analyzed the effects of TR57 treatment on the mTOR pathway in SUM159, a triple negative breast cancer model. Herein, I demonstrate that ClpP activation inhibits mTOR signaling as shown by loss of phosphorylation of mTOR substrates: eukaryotic translation initiation factor 4E-binding protein 1 (4E-BP1), ribosomal protein S6 kinase (p70S6K), and ribosomal protein S6 (S6). Thus, these results suggest that mTOR pathway inhibition may be involved in the reduction of protein synthesis and cell growth inhibition by ClpP activators.	Activation of Mitochondrial Protease ClpP Inhibits mTOR Activity in Triple Negative Breast Cancer	CSF
4:50-5:10	Megan Gaines Presentation Time: 4:50-5:10 Home University: North Carolina Central University Research Mentor: Adam Palmer, Department of Pharmacology Program: CSF Research Title: Comparisons of Resistances and Sensitivities to Chemotherapies in T-Cell Lymphomas The Non-Hodgkin’s T cell lymphoma (TCL) patient population consists of several cancer subtypes which have been historically treated with a single one-size-fits-all chemotherapy regimen known as CHOP. Several TCL subtypes do not respond well to CHOP, however, as nearly 40% of patients relapse within 2 years of treatment. There is a wide landscape of alternative chemotherapies that promote cures to TCLs in the relapsed and refractory setting, and it is likely that the varied effectiveness of these drugs is due to the broad biological heterogeneity of the overall patient population. We sought to determine which of 28 available chemotherapies are most effective at killing different TCL subtypes. We collected dose response measurements in vitro for three TCL cell lines after three-day chemotherapy treatments. Our results show that the two cell lines of the same subtype (SR-786 and Karpas-299) exhibited similar pharmacological responses to chemotherapies, while the third subtype (KHYG-1) displayed distinct sensitivities and resistances. Generally, drugs of similar mechanisms of action demonstrated consistent patterns of cell killing on the same cell lines, but there are notable differences that might correspond to specific molecular targets of these drugs. These experiments serve as initial categorization for a few diverse TCLs. Further dose response measurements with additional TCL cultures could identify more distinct individual responses to guide precision-based treatment approaches for TCL patients.	Comparisons of Resistances and Sensitivities to Chemotherapies in T-Cell Lymphomas	CSF

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