Effects of ICMT gene silencing on the invasion and migration of human salivary adenoid cystic carcinoma cells in vitro

To investigate the effect of isoprene cysteine carboxymethyltransferase (ICMT) gene on the migration and invasion of salivary adenoid cystic cancer cells (SACC) and the related mechanism, to provide experimental evidence for molecular targeted therapy of SACC.

Adenoid cystic cancer cells SACC-LM and SACC-83 were cultured in vitro, and siRNA was transfected into human SACC-LM and SACC-83 cells (experimental group) by transient transfection of a liposome vector. A blank control group and negative control group were set up respectively (transfected NC-siRNA). qRT-PCR was peformed to measure the mRNA expression of ICMT and RhoA in each group after transfection and to determine the silencing efficiency. The expression of ICMT, membrane RhoA, total RhoA, matrix metalloproteinase-2 (MMP-2), matrix metalloproteinase-9 (MMP-9) and Rho associated with coiled helical binding protein kinase 1 (ROCK1) in each group was detected by Western blot. The proliferation abilityies of SACC cells was detected by CCK-8 assay. The migration and invasion ability of SACC cells were detected by comparing the relative healing area of cell scratch assay and the number of Transwell assay cells.

After transfection of ICMT-siRNA into SACC-LM and SACC-83 cells, the expression of ICMT gene and protein in the experimental group was significantly decreased compared with the negative control group and blank control group (P＜0.05), but there were no significant differences in the expression of RhoA gene and total protein among all groups (P＞0.05). The expression of RhoA membrane proteins, ROCK1, MMP-2, MMP-9 in the experimental group was significantly decreased compared with that in the negative control group and blank control group (P＜0.05). Cell proliferation ability was significantly decreased (P＜0.05). The migration and invasion abilities were significantly decreased (P＜0.05).

In vitro silencing of ICMT gene can effectively inhibit the migration and invasion of human SACC-LM and SACC-83 cells, and the mechanism may be related to RhoA-ROCK signaling pathway.