Knockdown of IL35 inhibits migration and invasion of hepatocellular carcinoma by up-regulating autophagy-related proteins in HCC cells

To investigate the expression, clinical significance and potential molecular mechanism of interleukin 35（IL35）in hepatocellular carcinoma（HCC）.

A total of 40 pairs of HCC and adjacent tissues were collected. RT-qPCR and Western blotting were used to detect the expression of IL35 in the tissues, and the correlation of IL35 with clinical indicators was analyzed. The expression of IL35 was detected in normal liver cell line LO2 and 4 strains of HCC Huh7, Hep3B, SMMC7721 and Bel7402 cells by Western blotting. Lentiviral infection was used to down-regulate the expression of IL35 in Hep3B cells. Then CCK-8 assay and colony formation were employed to detect cell proliferation, Transwell assay was adopted to detect cell invasion and migration, and Western blotting was performed to detect autophagy and epithelial-mesenchymal transition（EMT）related indicators.

IL35 was highly expressed in HCC tissue（P<0.01）. Compared with HL7702 cells, IL35 was highly expressed in Hep3B, Huh7, SMMC7721 and BEL7402 cells, with the highest expression in Hep3B cells（P<0.01）. The high expression was associated with vascular invasion（P=0.0033）. Transwell assay showed that down-regulation of IL35 effectively inhibited the invasion and metastasis of Hep3B cells（P<0.01）; CCK-8 assay and plate cloning assay indicated that down-regulation of IL35 effectively inhibited the proliferation of Hep3B cells（P<0.01）. Western blotting results suggested that down-regulation of IL35 promoted the expression of LC3BII and Beclin1, inhibited the expression of p62（P<0.01）, enhanced the expression of E-cadherin and suppressed the expression of N-cadherin and vimentin（P<0.01）.

IL35 is highly expressed in HCC tissues and cells, and its expression is related to vascular invasion of HCC. Down-regulation of IL35 can inhibit the invasion and migration of HCC cells by inducing autophagy.