The function of miR-30b in colorectal cancer metastasis

Objective: To determine the function of miR-30b in the metastasis of colorectal cancer cells. Methods: RT-qPCR was performed to test miR-30b expression in 20 fresh primary colorectal cancer tissues and their corresponding adjacent tissues. Transwell and wound healing assays were performed to test the invasion and migration of colorectal cancer cells after miR-30b overexpression or inhibition. Bioinformatics assay was performed to predict miR-30b targets. Western Blot and Dual Luciferase reporter assay were per- formed to test the expressions of Snail and downstream target genes in colorectal cancer cells. Results: The results reveal that miR-30b expression decreased in cancer tissues compared with normal tissues. Transwell and wound healing assays reveal that miR-30b overex- pression inhibited cell invasion and migration, whereas miR-30b inhibition promoted the invasion and migration of colorectal cancer cells. Bioinformatics analyses reveal that miR-30b targets the 3'-UTR of Snail. Dual Luciferase reporter assay confirms that miR-30b af- fects the 3'-UTR of Snail. Western Blot analyses show that Snail and Vimentin expressions were significantly downregulated, whereas E-cadherin expression obviously increased after miR-30b overexpression. However, Snail and Vimentin expressions increased, but E-cadherin expression decreased after miR-30b inhibition. Conclusion: The miR-30b gene is downregulated in colorectal cancer tis- sues. The miR-30b protein may be important in the regulation of cell invasion and migration by targeting Snail in colorectal cancer cells.