Modulation of IGF2BP1 by long non-coding RNA HCG11 suppresses apoptosis of hepatocellular carcinoma cells via MAPK signaling transduction

Hepatocellular carcinoma (HCC) is a common malignancy of the liver. HCG11 is a member of long non-coding family, upregulation of which in HCC was proved by our previous study. In the present study, the role of HCG11 in the development of HCC was detected by focusing on the interaction between HCG11 and its target protein insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1). The expression status of HCG11 and IGF2BP1 was first investigated with clinical HCC samples. Then the expressions of HCG11 and IGF2BP1 were both inhibited in the human HCC cell line HepG2 and the cell viability, proliferation, apoptosis and metastasis potential of HepG2 cells were assessed. At molecular level, the expression levels of p-ERK, p-JNK, p-p38, p21 and cleaved caspase-3 were also determined to explain the pathways involved in the function of HCG11 in the progression of HCC. Expression of HCG11 and IGF2BP1 were significantly higher in HCC tissues than those in para-tumor tissues. Knockdown of both indicators led to decreased cell viability, proliferation, and migration ability in HepG2 cells while the cell apoptosis and G1 cell cycle arrest were induced after knockdown of HCG11 and IGF2BP1. In addition, suppressed activity of HCG11 and IGF2BP1 blocked the phosphorylation of anti-apoptosis factors, including ERK, JNK and p38 while the mitochondrial apoptosis in HCC cells was initiated by activation of p21 and cleaved caspase-3. HCG11 exerted its effect on HCC via interaction with IGF2BP1, leading to activation of MAPK signaling, which eventually promoted the progression of HCC.