Cancer Biology Commons^™

Atrx Inactivation And Idh1-R132h Drive Preferential Sensitivity To Proton Vs. X-Ray Radiotherapy In Glioma Stem Cells, Ángel Adrián Garcés

Dissertations & Theses (Open Access)

Background: Glioma Stem Cells (GSCs) are self-renewable, treatment resistant cells in the glioma tumor mass known to promote tumor development. In contrast to traditional photon-based radiation therapy (XRT), proton radiation therapy (PRT) may induce more complex DNA damage and therefore might have the potential to eliminate GSCs. Although previous studies have individually linked IDH mutations, specifically IDH1^R132H, and ATRX inactivating mutations to improved patient outcomes and suppressed DNA damage repair compared to their respective wild-types, the mechanisms by which these two genetic alterations interact in GSCs treated with PRT compared to XRT are currently unknown. We hypothesize that …

Lgr5 Regulation Of Stat3 Signaling And Drug Resistance In Colorectal Cancer, Tressie Posey, Tressie Alexandra Posey

Dissertations & Theses (Open Access)

LGR5 Regulation of STAT3 Signaling and Drug Resistance in Colorectal Cancer

Tressie Alexandra Capri Posey B.S.

Advisory Professor: Kendra Carmon, Ph.D.

The greatest difficulty in treating colorectal cancer (CRC) is the development of drug resistance which leads to relapse after treatment and progression to metastasis. Cancer stem cells (CSCs) are believed to drive relapse because of their capacity to self-renew, acquire resistance mechanisms, and differentiate promoting tumor growth and heterogeneity. Leucine-rich repeat-containing G protein-coupled receptor 5 (LGR5), is a bona-fide marker of CSCs and has been considered a viable target for CSC specific therapeutic development. While we showed targeting LGR5 …

Regulation Of Breast Cancer Initiation And Progression By 14-3-3zeta, Chia-Chi Chang

Dissertations & Theses (Open Access)

14-3-3ζ is a ubiquitously expressed family member of proteins that have been implicated to have oncogenic potential through its interactions and involvement in cancer initiation and progression. 14-3-3ζ belongs to the highly conserved 14-3-3ζ protein family and modulates numerous pathways in cancer. Overexpression of 14-3-3ζ is an early event, occurs in more than 40% of human breast cancer cases, and is associated with disease recurrence and poor prognosis. Metabolic reprogramming is a hallmark of cancer. Cancer cells elevate aerobic glycolysis to produce metabolic intermediates and reducing equivalents, thereby facilitating cellular adaptation to the adverse environment and sustaining fast proliferation. Interestingly, …

The Role Of Receptor Tyrosine Kinase Axl In Pancreatic Ductal Adenocarcinoma And Its Regulation By Hematopoietic Progenitor Kinase 1, Xianzhou Song

Dissertations & Theses (Open Access)

Pancreatic ductal adenocarcinoma (PDA) is one of the most aggressive malignancies with less than 5% of five year survival rate. New molecular markers and new therapeutic targets are urgently needed for patients with PDA. Oncogenic receptor tyrosine kinase Axl has been reported to be overexpressed in many types of human malignancies, including diffuse glioma, melanoma, osteosarcoma, and carcinomas of lung, colon, prostate, breast, ovary, esophagus, stomach, and kidney. However, the expression and functions of Axl in PDA are unclear. We hypothesized that Axl contributes to the development and progression of PDA. We examined Axl expression in 54 human PDA samples …

Role Of Prostaglandin E2 In The Regulation Of Pancreatic Stellate Cells Hyper Activity Associated With Pancreatic Cancer, Chantale Charo

Dissertations & Theses (Open Access)

Pancreatic cancer is one of the most lethal type of cancer due to its high metastasis rate and resistance to chemotherapy. Pancreatic fibrosis is a constant pathological feature of chronic pancreatitis and the hyperactive stroma associated with pancreatic cancer. Strong evidence supports an important role of cyclooxygenase-2 (COX-2) and COX-2 generated prostaglandin E2 (PGE2) during pancreatic fibrosis. Pancreatic stellate cells (PSC) are the predominant source of extracellular matrix production (ECM), thus being the key players in both diseases. Given this background, the primary objective is to delineate the role of PGE2 on human pancreatic stellate cells (PSC) hyper activation associated …

Cip4 And Src In Promoting The Migration And Invasion Of Breast Cancers, Christina S. Pichot

Dissertations & Theses (Open Access)

Cellular invasion represents a critical early step in the metastatic cascade, and many proteins have been identified as part of an “invasive signature.” The non-receptor tyrosine kinase Src is commonly upregulated in breast cancers, often in conjunction with overexpression of EGFR. Signaling from this pathway stimulates cell proliferation, migration, and invasion and frequently involves proteins that regulate the cytoskeleton. My data demonstrates that inhibition of Src, using the small-molecule inhibitor dasatinib, impairs cellular migration and invasion. Furthermore, Src inhibition sensitizes the cells to the effects of the chemotherapeutic doxorubicin resulting in dramatic, synergistic inhibition of proliferation with combination treatments. The …