Hyperactivation of IL-6/STAT3 pathway leaded to the poor prognosis of post-TACE HCCs by HIF-1α/SNAI1 axis-induced epithelial to mesenchymal transition

Transarterial chemoembolization (TACE) has been considered the standard treatment for intermediate-stage hepatocellular carcinoma according to BCLC algorithm. However, it has been unclear about the TACE-related predictive bio-markers and underlying molecular mechanisms. This investigation revealed that HCCs with higher HIF-1alpha suffered from unfavorable OS after TACE. mRNA expression microarray revealed that HIF-1alpha was potential target of p-STAT3 which was verified by ChIP and immunoblotting assay. Activation of IL-6/STAT3/HIF-1alpha signaling was found to promote EMT and chemoresistance to Doxorubicin in vitro and in vivo by regulating SNAI1. Hypoxia did not enhance HIF-1alpha expression and influence cell growth and chemoresistence to Doxorubicin in HCC cells when STAT3 expression was abolished. Taken together, HIF-1alpha overexpression in HCC tissues predicted the unfavorable outcome of HCCs after TACE and IL-6/STAT3 pathway resulted in EMT induced-metastases and chemoresistance of HCC after TACE through HIF-1alpha/SNAI1 axis.