MALAT1 promotes migration and proliferation of colorectal cancer cells through targeted regulation of miR-205 expression

Objective: To understand the mechanism of metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in colorectal cancer (CRC). Methods: qRT-PCR was applied to determine the expression of MALAT1 and microRNA-205 (miR-205) in CRC cells (DLD-1, SW480, HCT116, and SW620) and normal colon colonic epithelial cell (FHC). Stable MALAT1 inhibition vectors and miR-205 overexpression vectors were established and transfected into CRC cells (SW480 and HCT116), and then the cell counting kit-8 (CCK8), transwell assay, and flow cytometry were adopted to analyze the migration, proliferation, and apoptosis of the transfected cells, and the dual luciferase reporter assay was adopted to find out the correlation of MALAT1 with miR-205. Results: MALAT1 was up-regulated in the four kinds of purchased CRC cells, while the situation of miR-205 was opposite. Both inhibiting the expression of MALAT1 and up-regulating the expression of miR-205 could weaken the proliferation and migration abilities of SW480 and HCT116 cells and promote apoptosis of them. The dual luciferase reporter assay revealed targeted binding between MALAT1 and miR-205, and the rescue experiment revealed that inhibiting the miR-205 expression could prevent cell invasion, proliferation, and apoptosis caused by inhibiting MALAT1. Conclusion: MALAT1 could promote the development of CRC by inhibiting the expression of miR-205, and inhibition of MALAT1 is expected to be the treatment direction of CRC.