Effect of HPV16 oncoproteins on DNA damage repair pathways in human keratinocytes organotypic cultures

Abstract

Human papillomaviruses (HPV) are double-stranded DNA viruses that infect epithelial cells of skin and mucosa. Some HPV types, collectively known as high-risk types, are etiologically associated to almost all cervical tumors and more than 50% of other anogenital malignancies. Infection by these HPV types has been associated with genomic instability, a hallmark of most human malignancies. High-risk HPV types express two oncoproteins, E6 and E7, which target specific cellular factors to promote cell proliferation. Furthermore, these proteins induce structural and numerical chromosome alterations and modulate cellular response to DNA damage. Synthetic lethality describes a cellular condition in which two (or more) non-allelic and non-essential mutations, which are not lethal on their own, become deadly when present within the same cell. HPV transformed cells represent interesting models for the study of synthetic lethality since E6 and E7 oncoproteins target several signal transduction pathways such as those regulated by p53 and pRb. In this project we aim to systematically inhibit genes involved in DNA damage repair and tumor suppressor genes using lentiviral libraries expressing specific shRNA. This approach may contribute to identify genes that are essential for HPV-transformed cells survival and have potential for the development of anti-viral therapies to treat HPV infections. Besides, the results obtained during this project may prove useful for the study of other viral and non-viral associated tumors.