[Overexpression of Twist1 promotes tumor invasion in human tongue squamous cell carcinoma cell line Tca8113].

AIM: To construct an eukaryotic expression vector of human Twist1 and investigate the relationship between Twist1 overexpression and tumor invasion in human tongue squamous cell carcinoma cell line Tca8113.

METHODS

Total mRNA isolated from Tca8113 cells were reversely transcribed to cDNA. Human Twist1 was amplified using specific PCR primers and then subcloned into the pcDNA3.1-myc-hisA vector. The fusion expression plasmid was named Myc-Twist1. Myc-Twist1 was transfected into Tca8113 cells and examined by Western blotting. The localization of Twist1 in Tca8113 cells was observed using confocal laser scanning microscopy. E-cadherin promoter activity in response to Myc-Twist1 overexpression was measured by the dual luciferase reporter assay system. Transwell cell migration assay was performed to detect the invasive capacity of Tca8113 cells stably expressing Myc-Twist1.

RESULTS

The fusion protein Myc-Twist1 was successfully constructed into eukaryotic expression vector. Western blotting showed that Myc-Twist1 was stably expressed in Tca8113 cells and it was localized mainly in the nucleus and a little in the cytoplasm. The Twist1 significantly inhibited the E-cadherin promoter activity and enhanced the cell invasion.

CONCLUSION

Twist1 promotes tumor invasion by down-regulating E-cadherin expression in Tca8113 cells.