Abstract 949: Resistin potentiates stemness and chemoresistance of breast cancer cells through STAT3 activation: implications in breast cancer health disparity

Abstract

Abstract Breast cancer (BC) is most frequently diagnosed cancer and remains the second leading cause of cancer-related deaths in women in the United States. African American (AA) women bear an additional burden of BC with early onset of disease, poorer prognosis, higher risk of recurrence, and worst clinical outcome as compared to Caucasian American (CA) women. Emerging evidence strongly argue the role of tumor-microenvironment (TME) in BC of AA and CA racial backgrounds. On the similar line, our earlier findings suggested that serum levels of resistin; an inflammatory cytokine are significantly elevated in AA BC patients compared to their CA counterparts. Furthermore, we demonstrated that resistin promoted growth and aggressiveness of BC cells. In the present study, we investigated the role of resistin in stemness and chemoresistance of BC cells. For this, two BC cells of CA (MDA-MB-231) and AA (MDA-MB-468) origin were treated with resistin and sphere-forming ability, a key characteristic of cancer stem cells, was determined. Data demonstrate that number of spheres is significantly enhanced in both the BC cells upon resistin stimulation. Immunoblot analyses reveal that resistin-induced sphere-forming ability is associated with enhanced levels of stemness-associated transcription factors (Nanog and KLF4) in BC cells. We next examined if resistin conferred chemoresistance to BC cells. Our data suggest that resistin-treated MDA-MB-231 and MDA-MB-468 BC cells develop greater resistance against doxorubicin-induced cytotoxicity. Notably, the effects conferred by resistin were more prominent in AA BC cells comparing to CA BC cells. Our mechanistic studies unveiled an important role of STAT3 activation in the resistin-induced stemness and chemoresistance of BC cells. Taken together, our findings provide novel insight into the role of resistin in BC biology and further strengthen its role in racially disparate clinical outcomes. Citation Format: Sachin Kumar Deshmukh, Arun Bhardwaj, Sanjeev K. Srivastava, Nikhil Tyagi, Ahmed Al-Ghadhban, Ajay P. Singh, Donna L. Dyess, James E. Carter, Seema Singh. Resistin potentiates stemness and chemoresistance of breast cancer cells through STAT3 activation: implications in breast cancer health disparity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 949. doi:10.1158/1538-7445.AM2017-949