Aims: Laminin γ2 (LAMC2) is over-expressed in ovarian cancer, and its high expression facilitates cell invasion. Nevertheless, the effects of LAMC2 on other ovarian cancer cell functions and its underlying mechanism remain largely unclear. Bioinformatics analysis shows that LAMC2 is a predicted target of miR-125a-5p and miR-193a-3p. Therefore, the present study aimed to investigate the effects of LAMC2 in ovarian cancer progression and determine whether LAMC2 expression is under the regulation of miR-125a-5p or miR-193a-3p in ovarian cancer.

Materials and methods: Immunohistochemistry staining, western blot and qPCR were used to detect LAMC2 expression profiles. CCK-8, flow cytometry and tumour formation assays were used to assess cell proliferation, apoptosis and tumorigenesis. The interaction between miR-125a-5p/miR-193a-3p and LAMC2 were determined by the luciferase gene reporter assay.

Key findings: The results showed that LAMC2 was over-expressed in ovarian cancer tissues and cell lines. Over-expression of LAMC2 significantly promoted cell proliferation and repressed cell apoptosis, as well as increased the expression levels of p38, p-p38, c-myc and CREB, and translocated p38 protein to the nucleus. In addition, the promotion of cell proliferation and repression of cell apoptosis mediated by LAMC2 over-expression were all weakened when p38 was downregulated. Moreover, LAMC2 expression was negatively regulated by miR-125a-5p, which inhibited the nuclear accumulation of p38 protein. Upregulation of LAMC2 significantly abolished the effects of miR-125a-5p on cell proliferation inhibition and cell apoptosis promotion, as well as tumourigenesis repression.

Significance: The present study clarified that LAMC2 functioned as an oncogene in ovarian cancer through upregulating p38 under the regulation of miR-125a-5p.