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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 …

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 …