Study of p53 Gain of Function Mutations in p53-null Astrocytes

Abstract

STUDY OF GAIN OF FUNCTION MUTATION IN P53-NULL ASTROCYTES By Sang H. Choi A thesis submitted in partial fulfillment of the requirement for the degree of Master of Science at Virginia Commonwealth University. Virginia Commonwealth University, 2000. Major Director: Oliver Bogler, Ph.D., Assistant Professor, Department of Anatomy and Division of Neurosurgery. A number of recent studies suggest that expression of mutant p53 with mutations in certain codons show a gain of function and some of the characteristics of an oncoprotein. In order to study gain of function mutation and eliminate the potential of a dominant negative interaction with endogenous wild type p53 protein, p53 knockout mouse astrocytes were used. A retrovirus system was used to introduce mutant p53 genes into these p53-null astrocytes. Immunohistochemical staining and western blot experiments showed the expression of mutant p53 protein in these cells after infection with the mutant p53 retroviruses. Cell growth experiment did not suggest growth advantages for mutant p53 expressing astrocytes over vector control cells. Data from clonogenic survival assays following exposure to etoposide or cisplatin suggested that mutant p53 expressing cells with a point mutation at codon 273 may be resistant to