目的：探究miRNA-186-5p在结肠癌中的表达与功能。方法：用qPCR检测20例配对的结肠癌与其癌旁组织标本，以及正常肠上皮NCM460细胞与不同结肠癌细胞系（HCT-116、HRT-18、HT-29）中miRNA-186-5p的表达；分别用miRNA-186-5p模拟物或阴性对照组序列转染HCT-116细胞后，用CCK-8实验、平板克隆形成实验、划痕实验及Transwell侵袭实验检测细胞增殖、迁移和侵袭情况。结果：miRNA-186-5p在结肠癌组织中的表达明显低于相应癌旁组织中的表达，在各结肠癌细胞系中均明显低于正常肠上皮NCM460细胞（均P<0.05）；与转染阴性对照序列的HCT-116细胞比较，转染miRNA-186-5p模拟物的HCT-116细胞，细胞增殖能力明显降低、克隆形成数明显减少（114.0个vs. 311.7个）、划痕愈合率明显降低（28.7% vs. 77.0%）、侵袭细胞数明显减少（119.3个vs. 259.7个），差异均有统计学意义（均P<0.05）。结论：miRNA-186-5p在结肠癌组织中低表达或缺失，恢复miRNA-186-5p的表达水平能抑制结肠癌细胞的恶性表型，提示miRNA-186-5p在结肠癌中发挥抑瘤作用。
Relationship between miRNA-18-5p expression and malignant phenotype of colon cancer cells
Objective: To investigate the expression and function of miRNA-186-5p in colon cancer. Methods: The miRNA-186-5p expressions in 20 paired specimens of colon cancer tissue and adjacent tissues as well as in normal intestinal epithelial NCM460 cells and different colon cancer cell lines (HCT-116, HRT-18 and HT-29) were determined by qPCR. Then, in HCT-116 cells after transfection with miRNA-186-5p mimics or negative control sequences, the cell proliferation, migration and invasion were measured by CCK-8 assay, plate colony-forming assay, scratch wound-healing assay and Transwell invasion assay, respectively. Results: The miRNA-186-5p expression in colon cancer tissue was significantly lower than that in the adjacent tissue, and in each colon cancer cell line was significantly lower than that in normal intestinal epithelial NCM460 cells (all P<0.05). In HCT-116 cells transacted with miRNA-186-5p mimics compared with HCT-116 cells transfected with negative control sequences, the proliferative ability was decreased, colony forming units were reduced (114.0 vs. 311.7), wound healing rate was lowered (28.7% vs. 77.0%), and the number of invaded cells was decreased (119.3 vs. 259.7), and all the differences had statistical significance (all P<0.05). Conclusion: The miRNA-186-5p expression is down-regulated or absent in colon cancer tissues, and restoring miRNA-186-5p expression can suppress the malignant phenotype in colon cancer cells. So it is suggested that miRNA-186-5p may play an anti-cancer role in colon cancer cells.