Long non-coding RNA LINC00641 has been reported to regulate tumor progression in several cancers. However, the expression and function of LINC00641 in hepatocellular carcinoma (HCC) is still unclear.

Material and methods:
In this study, we measured the expression of LINC00641 in 79 pairs of HCC and adjacent normal liver tissues. The clinical significance of LINC00641 in HCC was explored. We also investigated the function of LINC00641 in HCC proliferation and invasion.

We observed that LINC00641 expression was significantly increased in HCC relative to normal tissues (P < 0.0001). High expression of LINC00641 was significantly associated with vascular invasion, advanced TNM stage, and reduced overall survival in HCC patients. Knockdown of LINC00641 inhibited the proliferation, colony formation, and invasion of HCC cells. In contrast, overexpression of LINC00641 promoted HCC cell growth and invasiveness. In vivo studies confirmed that knockdown of LINC00641 restrained tumorigenesis of HCC cells. Mechanistic studies revealed that LINC00641 inhibited the expression of miR-501-3p, which has been previously reported to act as a tumor suppressor in HCC. Furthermore, luciferase reporter assays validated that LINC00641 harbored a target site for miR-501-3p. Rescue experiments demonstrated that LINC00641-induced proliferation and invasion of HCC cells was reversed by co-expression of miR-501-3p.

Taken together, LINC00641 contributes to aggressive phenotype of HCC cells by sponging miR-501-3p and represents a promising therapeutic target for this disease.