To study the regulation of miR-127-3p on macrophage migration inhibitory factor (MIF) and its effect on the biological behavior of human renal cell carcinoma cell line GRC-1.

Human GRC-1 cells were transfected with miR-127-3p minic, MIF-overexpressed plasmid and cotransfected with miR-127-3p minic and MIF-overexpressed plasmid. The untreated cells were set as control. Real-time quantitative PCR was used to detect the expression of miR-127-3p and MIF mRNA in clinical renal cancer tissues and adjacent normal tissues, and the correlation between miR-127-3p and MIF mRNA expression levels in cancer tissues was analyzed by Pearson correlation. The luciferase reporter system determines the regulatory effect of miR-127-3p on MIF. The effects of miR-127-3p on cell proliferation, apoptosis, invasion and migration were analyzed, and the expression of MIF protein was detected. The measurement data between the two groups were compared by paired t-test, and the comparison between multiple groups was conducted by one-way ANOVA.

Compared with adjacent tissues, the expression of miR-127-3p was decreased in renal cancer tissue (1.16 ± 0.25 vs 1.65 ± 0.38), while the expression of MIF mRNA was significantly increased (1.32 ± 0.18 vs 0.32 ± 0.11, P < 0.05). The expression levels of miR-127-3p and MIF mRNA in renal cancer tissues were negatively correlated (r = - 0.612, P < 0.05). Luciferase experiments showed that miR-127-3p targeted MIF. Compared with the control, the MIF overexpression increased cell proliferation after transfection 2 ~ 4 days, while the miR-127-3p mimic decreased cell proliferation (P < 0.05). Compared with the control, the apoptosis rate was increased in the miR-127-3p mimic-transfected cells and co-transfected GRC-1 cells. In contrast, the apoptosis rate was decreased in the MIF-overexpressed cells. Compared with the control, the miR-127-3p mimic decreased the invasion number and MIF protein expression in renal cancer GRC-1 cells, while MIF overexpression, and co-transfection increased the cell invasion number (P < 0.05). Compared with the control, the scratch healing rate was decreased in the miR-127-3p mimic -transfected cells and co-transfected cells. While the scratch healing rate was increased in the MIF-overexpressed cells (P < 0.05) .

miR-127-3p is underexpressed in renal cancer tissues, and miR-127-3p overexpression inhibits the proliferation, migration and invasion and induces apoptosis of renal cancer GRC-1 cells by down-regulating the expression of MIF.