Steven Berberich (Advisor), Madhavi Kadakia (Committee Member), Michael Leffak (Committee Member)
Master of Science (MS)
The p53 tumor suppressor protein has the ability to transactivate its target genes whose gene products are involved in carrying out cell cycle arrest, apoptosis, DNA repair, and senescence. Here, I report that two genes may be p53 regulated. Utilizing a microarray method to search for novel p53 target genes, I was able to identify a possible transcriptional target of p53 being solute carrier family 1a1 (SLC1a1). Along with that finding I also identified an E2F-target gene, minichromosome maintenance 10 (MCM10), as being p53 regulated. Gene expression profiling of MCF7 breast cancer cells treated with RNAi targeting Hdm2 and HdmX in order to reactivate p53 led to increased SLC1a1 transcript levels. DNA damage experiments in several cell lines and along with a p53 overexpression experiments established that p53 activation does not directly result in a transcriptional increase in SLC1a1 expression. Thus the results suggest that SLC1a1 is not a transcriptional target of p53 and may have been a false positive result from the microarray experiment.
Gene expression profiling of MCF7 breast cancer cells treated with RNAi targeting Hdm2 and HdmX in order to reactivate p53 led to a transcriptional decrease in MCM10 expression. DNA damage experiments along with siRNA targeting Hdm2 and HdmX established that p53 activation leads to a reduction in MCM10 transcript levels. Furthermore, I established that the p53-mediated reduction of MCM10 mRNA levels is due to p53-mediated transactivation of p21, a well-known p53 target involved in cell cycle arrest. These results suggest that p53 activation leads to a reduction in gene expression of E2F target genes involved in cell cycle progression through transactivation of p21.
Department or Program
Department of Biochemistry and Molecular Biology
Year Degree Awarded
Copyright 2008, all rights reserved. This open access ETD is published by Wright State University and OhioLINK.