Purpose To investigate the expression level and the role of TUSC7 in human cutaneous malignant melanoma (CMM).Methods Quantitative real time-PCR (qRT-PCR) assay was performed to detect the expression of TUSC7 in 60 cases of CMM tissues,20 cases of benign nevus,4 CMM cell lines,and one normal human epidermal melanocytes.Then overexpression of TUSC7 was performed and its role in tumor progression was explored.Results TUSC7 expression was significantly downregulated in primary CMM tissues (n =60) compared to benign nevi (n =20),which were significantly downregulated in all the four melanoma cell lines,especially in A375 cells,compared with the normal melanocytes cells (all P ＜ 0.05).In comparison with the A375 cells transfected with the empty plasmid,those transfected with pcDNA-TUSC7 showed an obvious decrease in the proliferation and colony formation activity,while increase in the apoptosis rate (all P ＜ 0.05).Conclusion Our results suggested that the dysregulation of TUSC7 may play an important role in the CMM progression.