The Analysis of G-quadruplexes in Tumor Suppressor and Oncogene Promoters
Mentor:Dr. Luiza Nogaj, Assistant Professor of Biological Sciences, Mount St. Mary's College
G-quadruplexes are commonly found in telomeres and have recently been discovered in promoters. Their function at promoters is yet to be determined, but G-quadruplexes most likely inhibit or activate transcription. G-quadruplexes are composed of a series of G-quartets arranged in such a way that they can form two hydrogen bonds along each edge, where each G-quartet consists of four guanine bases. We used bioinformatics to determine whether selected tumor suppressor and oncogene promoters have the ability to form G-quadruplexes. As tumor suppressor genes are essential in the regulation of the cell cycle and can promote apoptosis in cancerous cells, it is important to understand the role G-quadruplexes have on this process. Similarly, as oncogenes have the ability to prevent cells undergoing apoptosis from dying, ultimately resulting in tumors, it is important to understand the relationship between promoters and their ability to form G-quadruplexes. So far, we have looked at the promoters of ten tumor suppressor genes: p53, APC, BRCA1, TCF21, CDKNIB, Rb, SDHB, WT1, VHL, and E2F1. These promoters contained a range of 3 to 20 possible G-quadruplexes. We are currently looking at the promoters of oncogenes to determine their ability to form G-quadruplexes as well. Overall, the effect of G-quadruplexes on tumor suppressor and oncogene promoters may be important in understanding the production and destruction of tumors.