Marni Siegel
Year: Junior
College/University: Duke University
Intended major/minor(s): Chemistry and Biology
Future career goals: MD or MD/PhD
Place of birth: Virginia Beach, VA
Hometown: Virginia Beach, VA
Hobbies: Tennis, Chemistry outreach
Faculty Mentor: Phil Febbo, MD
Summer Research Project: The effect of NFkB on androgen receptor transcriptional specificity in prostate cancer
Abstract: Marni B. Siegel, Alok K. Tewari, Phillip G. Febbo
Androgen receptor (AR) transcriptional activity is maintained in advanced prostate cancers, despite therapies targeted against it. In different prostate cancer cell line models, AR activation elicits different transcriptional and phenotypic responses. Our TRANSFAC analysis of the promoter regions of genes transcribed by the AR in one model (LNCaP) found significant enrichment of DNA sequences that can bind NFκB family proteins. Previous work has also suggested crosstalk between NFκB activation and the AR. Thus, we focused on elucidating the role of NFκB family proteins in AR transcriptional and phenotypic activity. Canonically, NFκB activation results in nuclear translocation of the p65(RelA)/p50 heterodimer and subsequent DNA binding. Therefore, we optimized a nuclear isolation protocol to fractionate the nuclear and cytoplasmic protein pools from different cell line models. Appropriate separation of these pools was confirmed using Western blotting for a known nuclear protein (HDAC2) and a known cytosolic protein (HSP90). Using Western blotting, we also assessed whole cell lysate levels of total IκK, phosphorylated IκK, total IκB and phosphorylated IκB as an initial examination of NFκB activation in response to AR activation. We detected small amounts of p-IκK in the LHSR-AR model independent of AR activation, but none in the LNCaP or LHMB-AR models. We detected p-IκB in all models, but higher levels of phosphorylation in LNCaP cells. These data suggest LNCaP cells have greater NFκB activation, independent of AR activation. Further work will examine nuclear levels of specific NFκB proteins in response to AR activation and the impact of these proteins on AR activity.