Abstract C73: Differences in UPR signaling in ER+ breast cancer between African American and Caucasian women

Abstract Cancer is one of the leading causes of death amongst ethnic minorities. African American women between the ages of 40 and 50 are associated with higher rate of mortality due to breast cancer compared to Caucasian women. Estrogen receptor positive (ER+) subtype is the most common amongst all races. However, amongst those with ER+ breast cancer, African American women face a higher mortality rate compared to Caucasian women. We hypothesize that this higher mortality in African American women is potentially due to increased drug resistance to anti-estrogen therapy and disease progression to either inherent or acquired resistance to endocrine therapy. Despite the clinical advances with anti-estrogen agent, tamoxifen, many women experience recurrence. We have shown that the endoplasmic reticulum (ER) plays an important role in anti-estrogen sensitivity through the unfolded protein response (UPR), a stress response for cellular self-preservation. The UPR pathway consists of three known pathways that eventually lead to either apoptosis (cell death) or autophagy (“self-eating”); PERK, ATF6 and IRE1a. We will investigate the potential difference between these signaling receptors and downstream signaling proteins affiliated with the UPR pathway between African American and Caucasian American ER+ breast cancer from public databases. Understanding whether the UPR is differently regulated in different ethnic background of women may help uncover why mortality in African American women with ER+ breast cancer has a higher mortality rate. Citation Format: Ahreej E. Eltayeb, Ayesha N. Shajahan-Haq, Krupesh Dave, Robert Clarke. Differences in UPR signaling in ER+ breast cancer between African American and Caucasian women. [abstract]. In: Proceedings of the Sixth AACR Conference: The Science of Cancer Health Disparities; Dec 6–9, 2013; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2014;23(11 Suppl):Abstract nr C73. doi:10.1158/1538-7755.DISP13-C73