Sec62 promotes early recurrence of hepatocellular carcinoma through activating integrinα/CAV1 signalling

Postsurgical recurrence within 2 years is the major cause of poor survival of hepatocellular carcinoma (HCC) patients. However, the molecular mechanism underlying HCC recurrence remains unclear. Here, we distinguish the function and mechanism of Sec62 in promoting HCC recurrence. The correlation between Sec62 and early recurrence was demonstrated in 60 HCC samples from a prospective study. HCC cells with Sec62 knockdown (Sec62(KD)) or overexpression (Sec62(OE)) were used to determine the potential of Sec62 in cell migration in vitro. Microarray analysis comparing Sec62(KD) or Sec62(OE) to their control counterparts was used to explore the mechanisms of Sec62-induced recurrence. A luciferase-labelled orthotopic nude mouse model of HCC with Sec62(KD) or Sec62(OE) was used to validate the potential of Sec62 in early HCC recurrence in vivo. We found that high expression of Sec62 was positively correlated with surgical recurrence in clinical HCC samples. Multivariate analysis revealed that Sec62 was an independent prognostic factor for early recurrence in postoperative HCC patients. Moreover, Sec62 promoted migration and invasion of HCC cells in vitro and postsurgical recurrence in vivo. Mechanically, integrin alpha/ CAV1 signalling was identified as one of the targets of Sec62 in cell movement. Overexpression of integrin alpha partially rescued the Sec62 knockdown-induced inhibition of cell migration. Sec62 is a potentially prognostic factor for early recurrence in postoperative HCC patients and promotes HCC metastasis through integrin alpha/CAV1 signalling. Sec62 might be an attractive drug target for combating HCC postsurgical recurrence.