Abstract

Being one of the four subunits that makes up the Negative Elongation Factor Complex (NELF), Cofactor of BRCA1 (COBRA1); also known as NELF-B, is able to regulate a number of genes involved in cellular proliferation, metabolism, cell cycle progression and DNA repair. In addition, COBRA1 was shown to interact with other transcription factors such as BRCA1, AP-1 complex and several nuclear receptors. Despite the evidences that suggest COBRA1 as a potential player involved in the progression of a number of cancers, its role in cervical cancer has not been previously investigated. To date, it has been studied in breast, upper gastrointestinal and liver cancers. The main objective of our study was to investigate the potential involvement of COBRA1 in cervical cancer progression. We first did in-silico analysis of the expression patterns of COBRA1 in cervical cancer tissues relative to normal cervical tissues using the publicly available Oncomine Cancer Microarray Database. Search results revealed a significant upregulation of COBRA1 in two mRNA microarray datasets. RNA interference technique was then used to knockdown COBRA1 expression in cervical cancer cell line, HeLa. Once a successful siRNA mediated silencing at the RNA and protein levels of COBRA1 was established and confirmed through semi-quantitative Reverse Transcription Polymerase Chain Reaction (RT-PCR) and Western Blot, we investigated its consequences on proliferation, migration and survival of HeLa cells. Interestingly, COBRA1 depletion resulted in a significant increase in the mRNA expression of Trefoil Factor 1 (TFF1) accompanied by a subsequent decrease in the β-catenin mRNA levels. These findings suggests an effect for COBRA1 on the Wnt/β-catenin signalling pathway, which could be mediated through TFF1. In addition, COBRA1 silencing resulted in significant decrease in the expression of survivin 2B and survivin DeltaEX3 isoforms while the observed decrease in survivin wild type form was found to be statistically insignificant. Survivin is known to play a major role in cancer cells proliferation and survival. Yet, the finding that the noted decrease in β-catenin and survivin expression was not reflected on the proliferation and migration abilities of HeLa is not conclusive and requires further investigations. Taken together, these findings could help as an initial step in identifying the role of COBRA1 in cervical cancer tumorigenesis.

Department

Biotechnology Program

Degree Name

MS in Biotechnology

Graduation Date

6-1-2018

Submission Date

May 2020

First Advisor

Amleh, Asma

Committee Member 1

Amleh, Asma

Committee Member 2

Abdelnaser, Anwar

Extent

55 p.

Document Type

Master's Thesis

Rights

The author retains all rights with regard to copyright. The author certifies that written permission from the owner(s) of third-party copyrighted matter included in the thesis, dissertation, paper, or record of study has been obtained. The author further certifies that IRB approval has been obtained for this thesis, or that IRB approval is not necessary for this thesis. Insofar as this thesis, dissertation, paper, or record of study is an educational record as defined in the Family Educational Rights and Privacy Act (FERPA) (20 USC 1232g), the author has granted consent to disclosure of it to anyone who requests a copy. The author has granted the American University in Cairo or its agents a non-exclusive license to archive this thesis, dissertation, paper, or record of study, and to make it accessible, in whole or in part, in all forms of media, now or hereafter known.

Institutional Review Board (IRB) Approval

Not necessary for this item

Comments

I am sincerely thankful to Mr. Moataz Al-Alfi for partially funding my studies at the AUC. I would to express much gratitude to the AUC for the research grant that supported this work.

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