Transformation-related changes in the simian virus 40 early genes in viral-infected human keratinocytes in vitro.
Item
-
Title
-
Transformation-related changes in the simian virus 40 early genes in viral-infected human keratinocytes in vitro.
-
Identifier
-
AAI9917709
-
identifier
-
9917709
-
Creator
-
Vazquez, Raymond.
-
Contributor
-
Adviser: Mark Steinberg
-
Date
-
1999
-
Language
-
English
-
Publisher
-
City University of New York.
-
Subject
-
Chemistry, Biochemistry | Biology, Genetics | Biology, Microbiology
-
Abstract
-
The experimental procedures described below were designed to study the alterations in the viral early region of the oncogenic virus SV40 integrated into the transformed cells of human keratinocytes. To achieve this goal the endogenous viral sequences of different human keratinocyte cell lines that have become immortalized by the virus were studied. The transformation of these nonpermissive cells can be divided into early and late phases. The viral early genes encode for two oncoproteins the large T-antigen and the small t-antigen. In the early stage of infection the cultured cell exhibit altered properties of growth which continue to change during the progression of long term culture. The late phase is characterized by the appearance of various transformed properties including accumulation of aberrant viral fragments and the expression of transformation related genes exhibiting altered patterns of gene expression. As transformed cells progress through several hundred cell generations the free viral DNA is gradually lost and only the viral sequences that are integrated into the host remain. Since the viral-infected cells have been carried in vitro for long periods of time, the viral sequences are found as either tandemly integrated full-length viral genomes or as subgenomic fragments. The expression of the viral early genes is considered to be essential for the maintenance of the transformed state, examination of the DNA sequence of the viral early region may identify transforming variants that are selected over long term culture. We sequenced the SV40 viral stock and compared it to the sequences of three different cell lines. Our sequence data has revealed mutational clusters present in all three of the cell lines studied. The mutational clusters were found at different positions in each individual cell line ruling out the possibility of a mutational hot spot in the viral genome. Experimental analyses in conjunction with a detailed investigation of the mutation sites have demonstrated that each series of mutations confers enhanced growth properties to the cells, which is consistent with the theory that these mutated viral integrants are selectively retained by their host.
-
Type
-
dissertation
-
Source
-
PQT Legacy CUNY.xlsx
-
degree
-
Ph.D.
