Abstract 111: Targeting STAT3 and telomerase for the treatment of colorectal cancer

Abstract

Abstract There is an increasing evidence of pro-inflammatory cytokines involvement in cancer development. Here, we found that two cytokines, IL-6 and TNF-α, induced colorectal cancer cells more active and invasive. Combined treatments of IL-6 and TNF-α phosphorylated transcription factors STAT3 in a synergistic manner. STAT3 and NF-κB physically interacted upon cytokine stimulation. Similarly, STAT1 hetero-dimerized with STAT3 and the binding affinity was enhanced with cytokine treatments. STAT3 bound the promoter region of human telomerase reverse transcriptase (hTERT), and IL-6 and TNF-α stimulation further enhanced this STAT3 binding affinity. Withaferin A, an anti-inflammatory steroidal lactone, inhibited the IL-6 and TNF-α induced cancer cell invasiveness and decreased colonosphere formation. Notably, withaferin A inhibited STAT3 phosphorylation and abolished the STAT3 and NF-κB interactions. STAT3 binding to hTERT promoter was inhibited and telomerase activity was decreased with the withaferin A treatments. Taken together, pro-inflammatory cytokines induced-cancer cell invasiveness is mediated by STAT3 regulated mechanism in colorectal cancer cells. Our study suggests the novel natural compound therapy for the metastatic colorectal cancer in clinical settings. Citation Format: Seyung Chung, Quincy Okobi, Debbie Adekoya, Jaydutt Vadgama. Targeting STAT3 and telomerase for the treatment of colorectal cancer [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 111. doi:10.1158/1538-7445.AM2017-111