[Detection and correlation analysis of miRNAs and myeloid-derived suppressor cells in ovarian cancer-bearing mice].

OBJECTIVE: To detect the levels of miR-21a-5p, miR-155-5p, miR-218-5p, miR-222-3p, miR-494-3p in ovarian cancer tissues and the number of myeloid-derived suppressor cells (MDSCs) in peripheral blood and spleen in ovarian cancer-bearing mice, and explore their clinical significance and correlations. METHODS: The mRNA expressions of miR-21a-5p, miR-155a-5p, miR-218-5p, miR-222-3p, miR-494-3p were detected by real-time quantitative PCR (qRT-PCR) in tumor tissues and tumor-adjacent normal tissues from 12 ovarian cancer-bearing mice. The frequency of MDSCs in the peripheral blood and spleen from the 12 tumor-bearing mice was measured by flow cytometry. Spearman correlation analysis was used to find out the correlations between MDSCs and miRNAs. RESULTS: Compared with the normal mice, the number of MDSCs in the peripheral blood and spleen of the tumor-bearing mice significantly increased. The levels of miR-21a-5p, miR-218-5p and miR-222-3p in tumor tissues were significantly higher than those in tumor-adjacent normal tissues; conversely, miR-155a-5p and miR-494-3p levels in the former were significantly lower than those in the latter. There was no correlation between miR-222-3p and MDSCs, but miR-494-3p had a negative correlation with MDSCs. The expression differences of miR-21a-5p, miR-155a-5p, miR-218-5p between tumor tissues and tumor-adjacent normal tissues had positive correlations with the number of MDSCs. CONCLUSION: The levels of miR-21a-5p, miR-155a-5p, miR-218-5p, miR-494-3p in tumor tissues had correlations with the number of MDSCs in the peripheral blood and spleen of ovarian cancer-bearing mice.