March 3, 2006
Regulation of Telomerase Activity by Epstein-BarrVirus in Burkitt Lymphoma
Marjannie Dionne Eloi and Dr. Ingrid Ruf
Department of Molecular Biology and Biochemistry
University of California, Irvine
Epstein-Barr virus (EBV) is an oncogenic herpesvirus which causes immortalization of human B lymphocytes in vitro and is associated with a number of malignancies including Burkitt Lymphoma (BL). In this study we have examined the effects of EBV infection on telomerase activity. Although over expression of c-MYC is a hallmark of BL irrespective of EBV status, EBV-positive BL cells down-regulate c-MYC protein levels when they enter into stationary phase growth. As telomerase activity is regulated by c-MYC, we propose that in EBV-positive BL cells telomerase activity will decrease during stationary phase, as a consequence of decreased c-MYC levels. By contrast, we expect no decrease in telomerase activity in EBV-negative BL cells, as MYC levels are unaltered during stationary phase. Furthermore, the virus produces two small non-coding viral RNAs, EBER-1 and EBER-2, that are known to interact with the ribosomal protein L22 which itself interacts with components of the telomerase complex. In this study we have also investigated whether EBER expression alters telomerase activity and disrupts the interaction between L22 and the RNA component of telomerase (hTR).