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The Role of Cyclin E in Pkc Iota-Driven Early Ovarian Tumorigenesis

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The Role of Cyclin E in Pkc Iota-Driven Early Ovarian Tumorigenesis The Texas Medical Center Library DigitalCommons@TMC The University of Texas MD Anderson Cancer Center UTHealth Graduate School of The University of Texas MD Anderson Cancer Biomedical Sciences Dissertations and Theses Center UTHealth Graduate School of (Open Access) Biomedical Sciences 5-2011 THE ROLE OF CYCLIN E IN PKC IOTA-DRIVEN EARLY OVARIAN TUMORIGENESIS Angela Nanos-Webb Follow this and additional works at: https://digitalcommons.library.tmc.edu/utgsbs_dissertations Part of the Biology Commons Recommended Citation Nanos-Webb, Angela, "THE ROLE OF CYCLIN E IN PKC IOTA-DRIVEN EARLY OVARIAN TUMORIGENESIS" (2011). The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences Dissertations and Theses (Open Access). 145. https://digitalcommons.library.tmc.edu/utgsbs_dissertations/145 This Dissertation (PhD) is brought to you for free and open access by the The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences at DigitalCommons@TMC. It has been accepted for inclusion in The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences Dissertations and Theses (Open Access) by an authorized administrator of DigitalCommons@TMC. For more information, please contact [email protected]. THE ROLEOF CYCLINE IN PKCIOTA-DRIVEN EARLY OVARIAN TUMORIGENESIS by AngelaNanos-Webb APPROVED: 14, n Keyomarsi,Ph.D. r-) AI/r J'/d.r 'l I L- Paul€hiao,Ph.D. GordonMills. M.D.. Ph.D. APPROVED: Dean,The Universityof Texas GraduateSchool of BiomedicalSciences at Houston THE ROLE OF CYCLIN E IN PKC IOTA-DRIVEN EARLY OVARIAN TUMORIGENESIS A DISSERTATION Presented to the Faculty of The University of Texas Health Science Center at Houston and The University of Texas M. D. Anderson Cancer Center Graduate School of Biomedical Sciences in Partial Fulfillment of the Requirements for the Degree of DOCTOR OF PHILOSOPHY by Angela Nanos-Webb Houston, Texas Date of Graduation: May, 2011 Abstract Among the gynecologic malignancies, epithelial ovarian tumors are the leading cause of death. For the past few decades, the only treatment has involved surgical resection of the tumor and/or general chemotherapies. In an attempt to improve treatment options, we have shown that several oncogenes that are overexpressed in ovarian cancer, PI3K, PKCiota, and cyclin E, all of which have been shown to lead to a poor prognosis and decreased survival, converge into a single pathway that could potentially be targeted therapeutically. Because of the ability of either PKCiota or cyclin E overexpression to independently induce anchorage-independent growth, a hallmark of cancer, we hypothesized that targeting PKCiota expression in ovarian cancer cells could induce a reversion of the transformed phenotype through down regulation of cyclin E. To test this hypothesis, we first established a correlation between PKCiota and cyclin E in a panel of 20 ovarian cancer cell lines. To show that PKCiota is upstream of cyclin E, PKCiota was stably knocked down using RNAi in IGROV cells (epithelial ovarian cancer cell line of serous histology). The silencing of PKCiota resulted in decreased expression of cell cycle drivers, such as cyclin D1/E and CDK2/4, and an increase in p27. These alteration in the regulators of the cell cycle resulted in a decrease in both proliferation and anchorage-independent growth, which was specifically through cyclin E, as determined by a rescue experiment. We also found that the mechanism of cyclin E regulation by PKCiota was at the level of degradation rather than transcription. Using two inhibitors to PI3K, we found that both the active form of PKCiota and total cyclin E levels decreased, implying that the PKCiota/cyclin E pathway is downstream from PI3K. In conclusion, we have identified a novel pathway in epithelial ovarian tumorigenesis (PI3K Æ PKCiota Æ Cyclin E Æ anchorage-independent growth), which could potentially be targeted therapeutically. iii Table of Contents Approval Sheet ............................................................................................................................ i Title Page .................................................................................................................................... ii Abstract ...................................................................................................................................... iii Table of Contents ....................................................................................................................... iv List of Illustrations ....................................................................................................................... x List of Tables ............................................................................................................................ xiii CHAPTER 1: Introduction Dissertation Overview ................................................................................................................. 1 Cancer Overview ........................................................................................................................ 2 Cancer ..................................................................................................................................... 2 Ovarian Cancer ...................................................................................................................... 2 Cyclin E ....................................................................................................................................... 8 Eukaryotic Cell Cycle ............................................................................................................... 8 Cyclin E .................................................................................................................................. 14 Cyclin E and Cancer ............................................................................................................. 19 Low Molecular Weight Cyclin E (LMW-E) ............................................................................ 21 Cyclin E and Transformation .................................................................................................. 23 (1) Evading Apoptosis .................................................................................................. 23 (2) Self-Sufficiency in Growth Signals .......................................................................... 24 (3) Insensitivity to Anti-Growth Signals ......................................................................... 24 (4) Sustained Angiogenesis ......................................................................................... 25 (5) Limitless Replicative Potential ................................................................................ 25 (6) Tissue Invasion and Metastasis .............................................................................. 25 Cyclin E and Anchorage-Independent Growth ..................................................................... 27 PKCiota .................................................................................................................................... 30 Note ...................................................................................................................................... 30 PKC Family of Serine/Threonine Kinases .............................................................................. 30 iv Initial Discovery of PKCiota/ Lambda and Characteristics ..................................................... 32 The Atypical PKCs: PKCiota/ Lambda versus PKCzeta ........................................................ 33 PKCiota Phosphorylation/ Activation ..................................................................................... 37 PKCiota has Diverse Functions ............................................................................................. 38 Polarity (Embryogenesis / Tissue) ........................................................................................ 38 Apical-Basal Polarity and Transformation ........................................................................... 42 Membrane Trafficking ........................................................................................................... 44 Inflammation ........................................................................................................................ 45 Proliferation .......................................................................................................................... 46 Differentiation ....................................................................................................................... 52 Diseases: Diabetes, Alzheimers, Cancer ............................................................................ 53 PKCiota in Cancer ................................................................................................................ 54 NSCLC (Non-small cell lung cancer) ............................................................................ 54 ESCC (Esophageal Squamous Cell Carcinoma) .......................................................... 54 Hepatic Metastasis of Colorectal Carcinoma ............................................................... 54 Malignant Meningioma and Glioma .............................................................................. 55 Breast Cancer ..............................................................................................................
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