lncARSR promotes liver cancer stem cells expansion via STAT3 pathway

Liver cancer stem cells (CSCs) have important functions in tumorigenesis, progression, recurrence and drug resistance of hepatocellular carcinoma (HCC). lncARSR has been reported to play an important role in the maintenance and self-renewal of renal cancer stem cells, but its role in liver cancer stem cells (CSCs) remains obscure. Herein, we observed high expression of lncARSR in chemoresistant hepatocellular carcinomas (HCCs). A remarkable increase of lncARSR expression in EpCAM or CD133-positive liver CSCs as well as in CSC-enriched hepatoma spheres. Interference lncARSR suppressed liver CSC expansion by inhibiting the dedifferentiation of hepatoma cells and decreasing the self-renewal ability of liver CSCs. Mechanistically, we found STAT3 as the downstream of lncARSR in HCC cells. The special STAT3 inhibitor S3I-201 abolished the discrepancy in liver CSC proportion and the self-renewal capacity between lncARSR knockdown hepatoma cells and control cells, which further confirmed that STAT3 was required in lncARSR promoted liver CSCs expansion. More importantly, interference lncARSR HCC cells were more sensitive to sorafenib or cisplatin treatment. This maybe means that patients with low lncARSR levels benefited from cisplatin or sorafenib treatment, but patients with high lncARSR expression did not. Conclusion: lncARSR was upregulated in liver CSCs and could promote HCC cells dedifferentiation and liver CSCs expansion by targeting STAT3 signaling.