Overexpression of transient receptor potential melastatin 6 during human oral squamous cell carcinogenesis

BACKGROUND/PURPOSE: Transient receptor potential melastatin (TRPM) channel is involved in cell proliferation and cell survival. Eight members (TRPM1–8) are within the TRPM subfamily. The current study is aimed to investigate TRPM6 expression in human oral carcinogenesis. MATERIALS AND METHODS: Sixty-six oral squamous cell carcinomas (OSCCs), 47 oral potentially malignant disorders (OPMD) with moderate-severe epithelial dysplasia (ED), 28 OPMD with mild ED, and 33 normal oral mucosa (NOM) samples were subjected to immunohistochemical staining. Two human oral cancer cell lines (OCCLs), an oral premalignant cell line (DOK), and a normal oral keratinocyte culture (HOK) were used for Western blot analysis. OCCLs were evaluated for proliferation, migration, invasion assays, and intracellular calcium concentration. RESULTS: TRPM6 protein expression in OSCC was significantly increased as compared with normal samples. Protein expression of TRPM6 in OCCLs was significantly higher as compared with HOK. Significant decreases in degrees of proliferation, migration, invasion, and intracellular calcium concentration were noted in OCCLs with TRPM6 siRNA transfection as compared with those without transfection. Significantly increased TRPM6 protein level was noted in OPMD with moderate-severe ED as compared with those with mild ED. CONCLUSION: Our results implicate that TRPM6 overexpression is potentially related to human oral carcinogenesis.