Medicine and Health Sciences Commons^™

Epigenetic States Regulate Tumor Aggressiveness And Response To Targeted Therapies In Lung Adenocarcinoma, Fan Chen

Theses and Dissertations--Toxicology and Cancer Biology

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related death worldwide, 85% of which are lung adenocarcinomas (LUAD). Although molecular studies of NSCLC identified targetable mutations of some oncogenes including BRAF, EGFR and ALK, no targeted therapies exist for most cases. Cancer epigenetics is the study of epigenetic modifications, including histone modifications, that control gene expression in cancer. Recent advances have revealed numerous epigenetic abnormalities in human cancers, and targeting epigenetic regulators could be effective at reversing dysregulated epigenetic programs or driving sensitivity to other targeted therapies.

Inhibitors of the histone methyltransferase EZH2 have recently been approved as …

Mechanisms Of Trinucleotide Repeat Instability During Dna Synthesis, Kara Y. Chan

Theses and Dissertations--Toxicology and Cancer Biology

Genomic instability, in the form of gene mutations, insertions/deletions, and gene amplifications, is one of the hallmarks in many types of cancers and other inheritable genetic disorders. Trinucleotide repeat (TNR) disorders, such as Huntington’s disease (HD) and Myotonic dystrophy (DM) can be inherited and repeats may be extended through subsequent generations. However, it is not clear how the CAG repeats expand through generations in HD. Two possible repeat expansion mechanisms include: 1) polymerase mediated repeat extension; 2) persistent TNR hairpin structure formation persisting in the genome resulting in expansion after subsequent cell division. Recent in vitro studies suggested that a …

Mutations Of Fus Cause Aggregation Of Rna Binding Proteins, Disruptions In Protein Synthesis, And Dysregulation Of Nonsense Mediated Decay, Marisa Elizabeth Kamelgarn

Theses and Dissertations--Toxicology and Cancer Biology

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by motor neuron death and subsequent muscle atrophy. Approximately 15% of ALS cases are inheritable, and mutations in the Fused in Sarcoma (FUS) gene contribute to approximately 5% of these cases, as well as about 2% of sporadic cases. FUS performs a diverse set of cellular functions, including being a major regulator of RNA metabolism. FUS undergoes liquid- liquid phase transition in vitro, allowing for its participation in stress granules and RNA transport granules. Phase transition also contributes to the formation of cytoplasmic inclusions found in the …

Multivariate Analysis To Identify Potential Biomarkers For Prognosis And Treatment Resistance In Head And Neck Cancer Patients, Christina Ann Wicker

Theses and Dissertations--Toxicology and Cancer Biology

It is estimated that nearly 50,000 individuals in the United States will be diagnosed with head and neck cancer in 2017 (American Cancer Society www.cancer.org). Ninety percent of oral cancers are head and neck squamous cell carcinoma (HNSCC). Major obstacles in the treatment of HNSCC are recurrence and treatment resistance, which contributes to increased mortality. Therefore, there is increased need to determine genetic alterations in HNSCC that may be ideal novel drug targets, and biomarkers to improve diagnostic and prognostic testing.

Abnormal localization and overexpression of base excision repair protein and transcriptional regulator Apurinic/Apyrimidic endonuclease (APE1) has been associated with …

Overcoming Treatment Resistance In Heterogeneous Tumors, Nikhil Hebbar

Theses and Dissertations--Toxicology and Cancer Biology

Most primary tumors are heterogeneous and are often composed of therapy-sensitive and emerging therapy-resistant cancer cells. Rather unexpectedly, treatment of therapy-sensitive tumor cells in heterogeneous tumor microenvironments resulted in apoptosis of the therapy-resistant cancer cells. We identified a novel Par-4 amino-terminal fragment (PAF, which includes amino acids 1-131 of Par-4) that is produced and released by therapy-sensitive cancer cells following therapy-induced caspase-dependent cleavage of the tumor suppressor Par-4. PAF caused paracrine apoptosis in therapy-resistant cancer cells. Unlike Par-4-inducible apoptosis, which is dependent on the cell surface GRP78 receptor, PAF produced cancer-selective apoptosis independent of cell surface GRP78 function. Par-4 contains …