MiR-29c-3p inhibits epithelial-mesenchymal transition to inhibit the proliferation, invasion and metastasis of cervical cancer cells by targeting SPARC

BACKGROUND: Cervical cancer is one of the most common gynecological malignancies. Cancer recurrence and the poor efficacy of cervical cancer treatments are mainly caused by invasion and metastasis of cervical cancer cells. This study is to investigate whether miR-29c-3p can inhibit epithelial-mesenchymal transition (EMT) by targeting secreted protein acidic and rich in cysteine (SPARC), thus inhibiting the invasion and metastasis of human cervical cancer cells. METHODS: The expression levels of miR-29c-3p and SPARC in cervical cancer tissues and non-tumor adjacent tissues, human normal cervical epithelial cell line Ect1/E6E7 and human cervical cancer cell lines HeLa, CaSki, C-33A, HT-3 and SiHa were detected. After the expression of miR-29c-3p and SPARC was intervened in C-33A and SiHa cells, RT-qPCR was used to detect the expression levels of miR-29c-3p and SPARC. Western blot was performed to observe the expression levels of SPARC and EMT-related proteins. The proliferation rate of C-33A and SiHa cells was measured using an MTT assay. The viability of the cells was determined using a cell colony formation assay. Apoptosis and cell cycle was measured using flow cytometry, and migration ability was observed using a wound healing assay. A transwell invasion assay was used to determine the invasion ability of the cells, whilst a dual-luciferase reporter assay verified that SPARC was a target gene of miR-29c-3p. RESULTS: miR-29c-3p was expressed at low levels in cervical cancer tissues and cells, while SPARC expression was upregulated. The luciferase reporter assay confirmed that miR-29c-3p targeted and bound to SPARC. MiR-29c-3p overexpression significantly inhibited the proliferation, invasion, migration, and cell cycle of cervical cancer cells, but promoted apoptosis. In the miR-29c-3p group (miR-29c-3p overexpression), EMT progression was inhibited by upregulating E-cadherin expression and downregulating N-cadherin, vimentin, and Snail expression, which was contrary to the results of the in-miR-29c-3p group (inhibition of miR-29c-3p expression). In the miR-29c-3p + SPARC group (miR-29c-3p overexpression + SPARC overexpression), the effect of miR-29c-3p overexpression on cervical cancer cell functions was reversed. CONCLUSIONS: miR-29c-3p can inhibit EMT by targeting SPARC, so as to inhibit the invasion and metastasis of cervical cancer cells.