Type

Text

Type

Dissertation

Advisor

Scarlata, Suzanne | Cao, Jian | Haltiwanger, Robert | Brown, Deborah | Zucker, Stanley.

Date

2015-08-01

Keywords

cell migration, invasion, metastasis | Molecular biology

Department

Department of Molecular and Cellular Biology.

Language

en_US

Source

This work is sponsored by the Stony Brook University Graduate School in compliance with the requirements for completion of degree.

Identifier

http://hdl.handle.net/11401/76489

Publisher

The Graduate School, Stony Brook University: Stony Brook, NY.

Format

application/pdf

Abstract

Cell migration is an early and essential step required for cancer cell invasion and metastasis, which remains a major hurdle in the war against cancer. Therefore, it is imperative that we find novel strategies and targets aimed at preventing this cellular process. The goal of my thesis was two-fold: 1) to characterize the role of KIAA1199 in cancer cell migration and 2) to develop and optimize a novel 3-dimensional (3D) invasion assay. KIAA1199 is highly upregulated in various forms of cancers but its function was hitherto unknown. By employing both loss-of- and gain-of-function studies the role of KIAA1199 in cancer cell migration was determined. Silencing of KIAA1199 in aggressive cancer cells lead to a mesenchymal-to-epithelial-transition (MET), while overexpression in epithelial cells resulted in loss of epithelial-like traits. KIAA1199 was found localized within the endoplasmic reticulum (ER) via interaction with the chaperone protein binding immunoglobulin protein (BiP). Mechanistically, expression of KIAA1199 resulted in a leak of calcium from the ER and a subsequent increase in cytosolic calcium. These alterations in calcium were found to be required for KIAA1199-mediated migration via translocation and activation of protein kinase c alpha (PKC&alpha). Upregulation of KIAA1199 was linked to hypoxia-induced activation of the KIAA1199 promoter via hypoxia-inducible-factor-2alpha (HIF-2&alpha). Cell migration downstream of HIF-2α was impaired upon silencing of KIAA1199, suggesting a role for KIAA1199 in response to hypoxia. Together, these data support the critical role of KIAA1199 in cancer cell migration and maintaining cancer mesenchymal status. Although the data presented herein support KIAA1199 as a potential target for inhibiting cancer dissemination, the use of a phenotypic screen targeting cancer cell invasion may expedite drug discovery programs. Therefore, considerable effort has been made in developing and optimizing a novel 3D invasion assay that involves surrounding cell-collagen hemispheres/dots within collagen to create a 3D environment for invasion. For standardization, a pitted plate was designed that controls location and shape of the dots, while dialdehyde dextran was added to the cell-collagen dots to maintain size by inhibiting collagen contraction. A protocol for dual staining was established to allow for automated counting and simultaneous detection of cytotoxicity. As proof of principle, the National Cancer Institute's Diversity Compound Library was screened, resulting in the positive identification of a compound known to inhibit cell motility. Together, these data validate the use of our assay in anti-cancer drug discovery programs aimed at converting life-threatening cancer into a chronic disease. | 109 pages

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