The mechanism of LMO7 in promoting the metastasis of colorectal cancer via CUL4A

Objective To investigate the expression of LIM domain only 7 (LMO7) in colorectal cancer and its mechanism of regulating the migration and invasion of colorectal cancer cells.Methods The levels of LMO7 in normal and colorectal cancer tissues were detected by qRT-PCR. The effect of LMO7 knockdown or overexpression on the migration and invasion of colorectal cancer cells were evaluated by Transwell assay. The co-expressed molecules of LMO7 were predicted by bioinformatic methods. The changes in the expression of CUL4A after LMO7 overexpression or silencing were examined by qRT-PCR and Western blot. The mechanisms by which LMO7 promoted the expression of CUL4A through binding to the promoter region of CUL4A were explored by chromatin immunoprecipitation (ChIP) experiments.Results Compared with normal tissues, the levels of LMO7 were upregulated in non-metastatic and metastatic colon cancer tissues (P<0.05). Compared with human normal colonic mucosal cell line FHC, the levels of LMO7 were significantly upregulated in five colon cancer cell lines (P<0.05). LMO7 knockdown inhibited the migration and invasion of HCT116 and SW480 cells, while overexpression of LMO7 enhanced the migration and invasion of these cells. Overexpression of LMO7 promoted the expression of CUL4A, while LMO7 silencing suppressed the expression of CUL4A. LMO7 might promote the expression of CUL4A through binding to the P3 region of CUL4A promoter.Conclusions LMO7 is highly expressed in colorectal cancer tissue and colorectal cancer cells. It promotes the migration and invasion of colorectal cancer through binding to the P3 region of CUL4A promoter to increase its expression.