MicroRNA-623 Inhibits Epithelial-Mesenchymal Transition to Attenuate Glioma Proliferation by Targeting TRIM44.

Objective: Glioma has the highest incidence among the different tumor types within the nervous system, accounting for about 40% of them. Malignant glioma has a high invasion and metastasis rate, which leads to the poor prognosis of patients. By targeting specific genes, microRNAs serve as key regulators in the epithelial-mesenchymal transformation (EMT) process, which could provide new insights into the treatment of glioblastomas (GBM). The detailed molecular role that miR-623 plays in GBM still remains unclear.

Materials and Methods: The level of miR-623 in GBM cells was evaluated by RT-PCR. The function of miR-623 overexpression on GBM cell proliferation, migration, and invasion was assessed by MTS, Transwell analysis, and colony formation assay. In addition, a mouse subcutaneous xenograft model was used to study in vivo effects. The binding between miR-623 and TRIM44 was verified by a dual-luciferase reporter assay and the regulatory function of miR-623 on EMT markers was evaluated using Western blot.

Results: The expression of miR-623 was repressed in the GBM cancer cell lines. MiR-623 overexpression or TRIM44 knockdown attenuated the proliferation, migration, and invasion of GBM cell lines. TRIM44 could facilitate the reverse suppression of EMT and miR-623 in GBM progression. MiR-623 was found to inhibit TRIM44 expression by directly binding to its 3'UTR. In addition, systemic delivery of miR-623 mimic reduced tumor growth and inhibited TRIM44 protein expression in tumor-bearing nude mice. Furthermore, our findings indicated that miR-623 overexpression or TRIM44 down-regulation impeded the proliferation and migratory ability of LN229 and U251MG glioma cells, and miR-623 attenuates TRIM44 -induced EMT by directly targeting the 3'UTR of TRIM44 , which could serve as preliminary research to identify potential therapeutic targets for future treatment of GBM.

Conclusion: Overall, microRNA-623 inhibits epithelial-mesenchymal transition to attenuate glioma proliferation by targeting TRIM44.