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Theses/Dissertations

KRAS

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Modulation Of Kras Structure And Dynamics By Kras Ubiquitination And Membrane Depolarization, Vinay Nair May 2022

Modulation Of Kras Structure And Dynamics By Kras Ubiquitination And Membrane Depolarization, Vinay Nair

Dissertations & Theses (Open Access)

KRAS, a 21 kDa small GTPase protein, functions as a molecular switch playing a key role in regulating cell proliferation. Dysregulation of KRAS signaling by oncogenic mutations leads to uncontrolled cell proliferation, a hallmark of cancer cells. Attempts to therapeutically target oncogenic KRAS have led to limited success resulting in a need to identify new mechanisms to targeting KRAS. The interaction of KRAS with its regulators, effectors, and the membrane present one such avenue. In this study, we investigated how post-translational covalent and environmental modifications could modulate these interactions of KRAS. Using computational molecular dynamics simulations, nuclear magnetic resonance spectroscopy …


Mutant Kras Alters Extracellular Vesicle Microrna Sorting In Pancreatic Cystic Neoplasms, Rachel L. Dittmar Dec 2021

Mutant Kras Alters Extracellular Vesicle Microrna Sorting In Pancreatic Cystic Neoplasms, Rachel L. Dittmar

Dissertations & Theses (Open Access)

Pancreatic ductal adenocarcinoma (PDAC) is among the deadliest cancers by organ site with a 5-year survival rate of just 10.8%. This is largely because most patients do not experience symptoms until the disease has already metastasized. The best hope to cure PDAC is surgery, which can only be done with a curative intent at an early stage when the disease is localized. There are no reliable circulating, body-fluid-based biomarkers to detect early stage PDAC or its precursor lesions in a timely manner for effective surgical intervention. When potential PDAC precursor lesions, such as mucinous pancreatic cysts are found, there are …


Targeting Plasma Membrane Phosphatidylserine Content To Inhibit Oncogenic Kras Function, Walaa E. Kattan Aug 2021

Targeting Plasma Membrane Phosphatidylserine Content To Inhibit Oncogenic Kras Function, Walaa E. Kattan

Dissertations & Theses (Open Access)

The small GTPase KRAS, which is frequently mutated in human cancers, must be localized to the plasma membrane (PM) for biological activity. We recently showed that the KRAS C-terminal membrane anchor exhibits exquisite lipid-binding specificity for select species of phosphatidylserine (PtdSer). We therefore investigated whether reducing PM PtdSer content is sufficient to abrogate KRAS oncogenesis. Oxysterol-related binding proteins ORP5 and ORP8 exchange PtdSer synthesized in the ER for phosphatidylinositol-4-phosphate (PI4P) synthesized in the PM. We show that depletion of ORP5 or ORP8 reduced PM PtdSer levels, resulting in extensive mislocalization of KRAS from the PM. Concordantly, ORP5 or ORP8 depletion …


Structure Based Drug Design Of High Affinity Kras Inhibitors, Michael Mccarthy May 2018

Structure Based Drug Design Of High Affinity Kras Inhibitors, Michael Mccarthy

Dissertations & Theses (Open Access)

RAS, one of the most well characterized membrane-associated small GTPases, is a notorious oncogene with >15% of all tumors harboring RAS mutations. When RAS is mutated it becomes constitutively active sending cell growth, survival and proliferation into overdrive, which subsequently leads to cancer. Although, RAS has been aggressively targeted with drug design efforts for more than 30 years an FDA approved direct inhibitor has not yet been developed. There are three isoforms of RAS in cells; HRAS, NRAS and KRAS. We focused on KRAS since it is the most frequently mutated isoform in cancer. To identify novel non-covalent small molecules …


Concomitant Targeting Of The Mtor/Mapk Pathways: Novel Therapeutic Strategy In Subsets Of Non-Small Cell Lung Cancer, Dennis Ruder Dec 2016

Concomitant Targeting Of The Mtor/Mapk Pathways: Novel Therapeutic Strategy In Subsets Of Non-Small Cell Lung Cancer, Dennis Ruder

Dissertations & Theses (Open Access)

Over the last decade, a paradigm-shift in lung cancer therapy has evolved into targeted-driven medicinal approaches. However, patients frequently relapse and develop resistance to available therapies. Herein, we utilized genomic mutation data from advanced chemorefractory non-small cell lung cancer (NSCLC) patients enrolled in the Biomarker-Integrated Approaches of Targeted Therapy for Lung Cancer Elimination (BATTLE-2) clinical trial to characterize novel actionable genomic alterations potentially of clinical relevance. We identified RICTOR alterations (mutations, amplifications) in 17% of lung adenocarcinomas and found RICTOR expression correlates to worse overall survival. There was enrichment of MAPK pathway genetic aberrations in key oncogenes (e.g. KRAS, BRAF, …


Differential Activity Of The Kras Oncogene By Method Of Activation: Implications For Signaling And Therapeutic Intervention, Nathan Ihle Dec 2012

Differential Activity Of The Kras Oncogene By Method Of Activation: Implications For Signaling And Therapeutic Intervention, Nathan Ihle

Dissertations & Theses (Open Access)

Despite having been identified over thirty years ago and definitively established as having a critical role in driving tumor growth and predicting for resistance to therapy, the KRAS oncogene remains a target in cancer for which there is no effective treatment. KRas is activated b y mutations at a few sites, primarily amino acid substitutions at codon 12 which promote a constitutively active state. I have found that different amino acid substitutions at codon 12 can activate different KRas downstream signaling pathways, determine clonogenic growth potential and determine patient response to molecularly targeted therapies. Computer modeling of the KRas structure …