Defense Date

2016

Document Type

Thesis

Degree Name

Master of Science

Department

Human Genetics

First Advisor

Dr Andrei Ivanov

Abstract

Cell migration is an important component of many physiological and pathological processes such as tissue and organ morphogenesis during development, wound healing, inflammatory immune response, and tumor metastasis. The actin cytoskeleton is the basic engine driving cell migration. In the present study, we elucidate the role of an important actin interacting proteins, Adducins, in motility of normal lung epithelium and lung cancer cells. Adducins are the family of cytoskeleton protein capping the fast growing end and facilitating the bundling of actin filaments. Adducins are encoded by the three closely related genes namely alpha (ADD1), beta (ADD2) and gamma (ADD3) Adducin. ADD1 and ADD3 are ubiquitously expressed, whereas ADD2 is most abundant in brain and erythrocytes. Adducins are also involved in recruiting spectrin to the actin filaments forming spectrin-actin membrane skeletal network. Its role in cell motility remains controversial. In this study, we observed that CRISPR/Cas9 mediated stable knockout of ADD1 and ADD3 in 16HBE normal lung epithelium cells significantly increases transfilter migration of cells. On the other hand, stable overexpression of ADD1 in H1299 Non-Small Cell lung cancer cells significantly decreases wound healing, transfilter migration and Matrigel invasion of the cells. Importantly, the effects of Adducin depletion and overexpression on cell motility were not due to altered cell proliferation. ADD1 overexpressed H1299 cells were characterized by the increased adhesion and spreading on the collagen matrix. Fluorescence microscopy revealed alterations in their cortical actin cytoskeleton that was manifested in the assembly of peripheral F-actin bundles and formation of filopodia-like protrusions. These findings suggest that Adducins are negative regulators of motility of normal lung epithelial and lung cancer cells that act by altering the architecture of submembranous actin cytoskeleton and modulating cell adhesion to the extracellular matrix.

Rights

© The Author

Is Part Of

VCU University Archives

Is Part Of

VCU Theses and Dissertations

Date of Submission

7-27-2016

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