? In this renewal FIRCA application, we propose to examine the changes in cellular gene expression that occur during progression to malignancy in HPV-positive cancers. This is a joint proposal from the Laboratory of Tumor Transforming Proteins of the Cancer Research Center in Moscow Russia and the laboratory of Dr.
L aim onis A.
L aimi ns at Northwestern University in Chicago, IL. These studies are complementary to the aims of the parental NIH grant (CA59655) awarded to Dr.
L aimi ns entitled """"""""Regulation of Papillomavirus Gene Expression"""""""". In our recently completed studies supported by a FIRCA grant, we determined that approximately 50% of HPV-16 positive anogenital tumors contain exclusively episomal forms of expressed HPV DNA. The remainder contains either exclusively integrated forms or a combination of both. It was further determined that integration into host sequences was random and that there was no specific sequences at the sites of integration. While some mutations were identified in the URR, Et and E2 open reading frames, no correlation of mutation with integration was found. For this renewal application we will focus on the changes in cellular gene expression that are induced by HPV gene products and investigate how these may contribute to malignant conversion. For these studies the Moscow groups will examine already available frozen tumor samples from patients at various progressive stages of HPV-induced cancers. To insure homogeneity of cell types, tumor cells will be isolated by laser capture microdissection, a process at which the Moscow group is very skilled. The Moscow group will then examine changes in gene expression. Using these methods we will ask the following: ? 1). Are changes in cellular gene expression seen in microarray analyses of HPV tumor cell lines also detected in a variety of tumors at various stages in vivo? Are these changes seen at multiple stages of progression? ? 2). What changes in gene expression as determined by microarray analysis are seen in tumors containing either integrated or episomal HPV genomes? 3). What are the mechanisms by which changes in cellular gene expression are induced by HPVs? What role does methylation play during progression? ? ?
