Abstract 1065: IL-6 and IGF-1 receptor signal in stemness expression of HBV-related hepatocellular carcinoma .

Proceedings: AACR 104th Annual Meeting 2013; Apr 6-10, 2013; Washington, DC Expression of cancer stemness in hepatocellular carcinoma (HCC) is linked to drug resistance and tumor relapse which challenge the current therapy. However, mechanisms underlying the regulation of cancer stemness in HCC remain unclear. Effects of interleukin (IL)-6 and insulin-like growth factor I (IGF-I) on stemness expression in HCC were examined using OCT4/NANOG promoter luciferase reporter assays, RNA interference, secondary sphere formation, side population assay, and a xenograft animal model. Western blot analysis and immunohistochemical staining were used to detect the expression of OCT4/NANOG and phospho-IGF-I receptor (p-IGF-IR) in tissues. Levels of OCT4/NANOG and IGF-IR expressions were analyzed by real-time quantitative reverse transcriptase polymerase chain reaction (qPCR) and their association with tumor recurrence of hepatectomized HCC patients (n = 119) was determined using a Kaplan-Meier survival analysis. A high positive correlation between OCT4/NANOG and IGF-IR/p-IGF-IR expressions in human HCC tissues was observed. The concurrent expression of OCT4/NANOG/IGF-IR was mostly confined to HBV-related HCC (HBV-HCC) and was significantly associated with early tumor recurrence. Investigation of the underlying mechanism showed that IL-6 stimulated the autocrinal IGF-I/IGF-IR expression in a STAT dependent manner, and IGF-I/IGF-IR activation promoted the expression of stemness-related properties of Hep3B cells in both cell lines and xenograft murine models. IL-6 stimulated the expression of stemness-related properties in Hep3B cells, and inhibition of IGF-IR activation significantly suppressed the IL-6’s effects both in vitro and in vivo. Conclusions: Expression of OCT4/NANOG is regulated by IL-6-mediated IGF/IGF-IR signaling in HBV-HCC and is associated with the early recurrence of HCC. Citation Format: Te-Sheng Chang, Thai-Yen Ling, Yu-Chih Wu, Wei-Chi Su, Jaw-Ching Wu, Ching-Chi Chi, Pey-Jium Chang, Jui-Hung Chang, Ya-Ting Yang, Kam-Fai Lee, Jun-Jen Liu, Shui-Yi Tung, Yen-Hua Huang, Liang-Mou Kuo, Hong-Nerng Ho, Yen-Hua Huang. IL-6 and IGF-1 receptor signal in stemness expression of HBV-related hepatocellular carcinoma . [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1065. doi:10.1158/1538-7445.AM2013-1065