Abstract:

Xu Yan, Dong Dake, Hua Haikang, Zhu Xiaohong Department of Oncology, Wuxi No.2 People′s Hospital, Wuxi 214002, China （Xu Y）; Department of Dermatology, Wuxi No.2 People′s Hospital, Wuxi 214002, China （Dong DK, Hua HK, Zhu XH） Corresponding author: Zhu Xiaohong, Email: zxh6801@126.com 【Abstract】 Objective To determine the of miRNA211 （miR-211） in the development of malignant melanoma, and to investigate the correlation between miR-211 and its target molecule, matrix metalloproteinase 16 （MMP-16）. Methods Cultured A375 melanoma cells were divided into 3 groups: miR-211 over group and mock-vehicle group transfected with miR-211 mimics and empty vehicle respectively, and negative control group receiving no treatment. TaqMan fluorescence-based quantitative PCR was performed to determine the of miR-211 in HER1 primary melanocytes, A375, C32 and G361malignant melanoma cell lines, as well as in nevus tissues （n = 18） and melanoma tissues （n = 41）, and to evaluate changes of MMP-16 mRNA in A375 cells before and after the over of miR-211. Sulforhodamine B （SRB） assay and flow cytometry were conducted to evaluate cellular proliferative activity and determine cell cycle distribution respectively, and methylcellulose assay and Transwell assay to evaluate colony formation and cell migration abilities respectively. The size of selected colonies was used to represent colony formation ability, while the ratio of the number of migrating cells to that of non-migrating cells to represent cell migration ability. Results There were significant differences in the level of miR-211 among the G361, C32 and A375 cells （0.09 ± 0.02 vs. 0.000 52 ± 0.000 20 vs. 0.000 03 ± 0.000 01, F = 10 410, P < 0.01）. The of miR-211 was significantly decreased in melanoma tissues compared with nevus tissues （0.17 ± 0.03 vs. 0.87 ± 0.08, t = 9.118, P < 0.01）. No significant differences were observed in cellular proliferative activity or cell cycle distribution among the miR-211 over group, mock-vehicle group and negative control group. Compared with the mock-vehicle group, the miR-211 over group showed significantly suppressed colony formation （0.49 ± 0.05 vs. 0.85 ± 0.09, t = 2.19, P < 0.05） and cell migration （0.49 ± 0.06 vs. 0.82 ± 0.09, t = 3.15, P < 0.05） abilities, while no significant difference was observed between the mock-vehicle group and negative control group. Additionally, the mRNA of MMP-16 significantly decreased in the miR-211 over group compared with the mock-vehicle group after transfection （24 hours: 0.33 ± 0.02 vs. 0.91 ± 0.03, t = 11.30, P < 0.01; 48 hours: 0.52 ± 0.01 vs. 0.96 ± 0.02, t = 5.02, P < 0.05; 72 hours: 0.71 ± 0.01 vs. 0.97 ± 0.03, t = 3.85, P < 0.05）, with no significant difference between the mock-vehicle group and negative control group at the above time points. Conclusions miR-211 was lowly expressed in both malignant melanoma cells and tissues, and it could inhibit both anchorage-independent growth and migration of melanoma cells. After up-regulation of miR-211 , the mRNA of MMP-16 decreased in A375 cells, suggesting that MMP-16 may be a downstream target of miR-211, and can influence melanoma metastasis.