Objective  To investigate the roles and molecular mechanism of microRNA-491 (miR-491) in the proliferation, invasion and migration of cervical cancer (CC) cells and its molecular mechanism.

  Methods  A total of 58 pairs of cancer tissue and paracancerous tissue samples from CC patients were collected. The expression levels of miR-491 and Xenopus kinesin-like protein 2 target protein (TPX2) in CC tissues and paracancerous tissues were detected by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR). Hela and HT-3 cells of CC cell line were randomly divided into NC groupphosphate buffer (PBS) treatment, miR-491 group (overexpression of miR-491 treatment), si-TPX2 group (inhibition of TPX2), TPX2 group (overexpression of TPX2) and miR-491+TPX2 group (simultaneous overexpression of miR-491 and TPX2). Cell viability and clone formation assays were used to determine the effect of miR-491 on the proliferation ability of CC cells. The targeting relationship between miR-491 and TPX2 was verified by dual-luciferase reporter assay. Scratch and invasion assays were used to detect the effect of miR-491 on the invasion and migration of CC cells. A nude mouse tumorigenic model was constructed to verify the effects of miR-491 and TPX2 on tumor growth.

  Results  The results of the study showed that the expressions of miR-491 in CC tissues and cells were significantly reduced, while the expressions of TPX2 were significantly increased, and the differences were statistically significant (P<0.05). Overexpression of miR-491 could inhibit the cell proliferation of CC cells. The results of the dual luciferase report showed that miR-491 could significantly reduce the luciferase activity of PmirGLO-TPX2-3′UTR WT compared with the NC group (P<0.05). The test results of cell viability and apoptosis found that miR-491 mimics can significantly inhibit cell proliferation and increase the rate of apoptosis by regulating TPX2. Further scratches and transwell detection revealed that the miR-491 overexpression inhibited cell migration and invasion, while overexpression of TPX2 could promote cell migration and invasion. In addition, this effect was reversed by the overexpression of miR-491. From the results of tumor volume and weight detection, it is found that miR-491 could inhibit tumor growth, while overexpression of TPX2 can promote tumor growth, and its promotion effect was reversed by miR-491. Further detection of hematoxylin and eosin staining(HE) showed that the tumor tissues in the miR-491 group showed partial ring necrosis, while the tumor cell proliferation effect in the TPX2 group was obvious.

  Conclusion  This study confirms that miR-491 can affect the progress of CC by regulating the expression of TPX2, which provides a theoretical basis for the selection of cervical cancer biomarkers and therapeutic targets in the future.