A genetic screening for the tumour suppressive anticancer genes
File(s)
Author(s)
Ding, Qize
Type
Thesis
Abstract
Here, using a gain of function genetic screen approach I investigated 377 human apoptosis inducer genes that were previously isolated in HEK293T cells, and performed several rounds of genetic screens to isolate 22 human anticancer genes that only induce cell death in transformed but not normal cells. Later, using the genetically well-characterised cell line HEK293T as well as establishing transformed variants overexpressing individual oncogene, mutated genes or by knocking down tumour suppressor genes, I performed a separate genetic ‘synthetic lethal screen’ to identify a number of transformation scenarios in which these anticancer genes are targeted. Of these 22 anticancer genes, 16 showed a pronounced cell death inducing effect against c-Myc upregulation. c-Myc overexpressing cells were characterised to show phenotypic differences compared to their normal counterpart. On further validation, c-Myc specificity for these 16 genes was confirmed in a different cellular background in which some of these genes show inverse correlation to c-Myc expression. The last part of my project is to explore the molecular mechanism by which these 16 c-Myc specific anticancer genes induced cell death in c-Myc overexpressing cells. For the gene 1A3 (TMEFF2), my data indicated that it inhibited NF-B activity and CDK5 by inducing c-Myc specific cell death. In addition, 3 other genes 3B6, 4G3 and 4G4 also showed to induce c-Myc specific cell death through inhibition of FOXK2 in c-Myc overexpressing cells. In conclusion, I demonstrate that this ‘gain of function’ genetic screening strategy is useful for the isolation of tumour suppressor genes, but the establishment of their potential ‘anticancer’ functions would require further understanding of their molecular modes of action.
Version
Open Access
Date Issued
2016-12
Date Awarded
2017-07
Advisor
Lam, Eric
El-Bahrawy, Mona
Sponsor
University of Dammam
Publisher Department
Department of Medicine
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)