CADM1/TSLC1 inhibits melanoma cell line A375 invasion through the suppression of matrix metalloproteinases.

ABSTRACT

Increasing evidence has demonstrated that cell adhesion molecule 1/tumor suppressor in lung cancer 1 (CADM1/TSLC1) is crucially implicated in various biological processes, including proliferation, apoptosis, and invasion during tumorigenesis and development. However, the mechanism underlying its suppression of tumor growth and metastasis in melanoma remains elusive. The aim of the present study was to examine if CADM1/TSLC1 was able to induce growth suppression in melanoma. The plasmid pcDNA3.1­CADM1/TSLC1 was transfected into A375 cells (a human melanoma cell line). The expression of CADM1/TSLC1 in the transfected cells was determined by RT­PCR and western blotting analysis. Cell growth was measured by an 3­(4,5­dimethylthiazol­2­yl)­2,5­diphenyl­tetrazolium bromide assay and cell apoptosis was determined by flow cytometry, while a transwell assay was utilized to measure the ability of invasion. The expression of MMP­2 and MMP­9 in the transfected cells was determined by western blotting analysis. RT­PCR and western blotting revealed that in pcDNA3.1­CADM1/TSLC1 the protein expression of CADM1/TSLC1 protein was higher than in the pcDNA3.1 and A375 cells. The expression of MMP­2 and MMP­9 was lower in the pcDNA3.1­CADM1/TSLC1 than that in the pcDNA3.1 and A375 cells. The growth of CADM1/TSLC1­transfected cells was significantly suppressed in vitro and the ability of invasion was also reduced, CADM1/TSLC1 was able to induce cell apoptosis. Furthermore, CADM1/TSLC1 was an anti­invasive gene, the overexpression of which inhibited the invasion of A375 cells. This inhibition may be due to the suppression of the MMP­2 and MMP­9 expression, which is relative to tumor metastasis and progression.