MicroRNA-433 inhibits cervical cancer progression by directly targeting metadherin to regulate the AKT and β-catenin signalling pathways

Cervical cancer is one of the most common female malignancies worldwide. Emerging data have shown that microRNAs (miRNAs) play significant roles in various human cancers, including cervical cancer. Aberrantly expressed miRNAs in cervical cancer contribute to tumour occurrence and development as either tumour suppressors or promoters. Research suggests that miRNA-433 (miR-433) possibly plays an important role in the development of various cancer types. However, no study has explored the expression patterns, roles and underlying mechanisms of miR-433 in cervical cancer. In the present study, we demonstrated significant downregulation of miR-433 in cervical cancer tissues and cell lines. Low miR-433 expression was found to significantly correlate with patient characteristics including tumour size, International Federation of Gynecology and Obstetrics stage, lymph node and distant metastases. Functional studies showed that restoration of miR-433 inhibited cell proliferation and invasion and increased apoptosis in cervical cancer cells. Metadherin (MTDH) was also validated as a direct target gene of miR-433. MTDH mRNA expression was upregulated in cervical cancer tissues and was inversely correlated with miR-433 expression. MTDH knockdown showed similar tumour-suppressive roles as miR-433 overexpression in regards to cervical cancer cell proliferation, invasion and apoptosis. Rescue experiments revealed that MTDH overexpression markedly reversed the effects of miR-433 overexpression in regards to proliferation, invasion and apoptosis of cervical cancer cells. Further investigations revealed that miR-433 inactivated AKT and β-catenin pathways in cervical cancer. Collectively, these findings indicate the essential roles of miR-433 in suppressing cervical cancer progression and suggest its potential as a therapeutic target for the treatment of cervical cancer.