Overexpression of tuberous sclerosis complex 2 exerts antitumor effect on oral cancer cell lines.

Tuberous sclerosis is caused by mutations in tuberous sclerosis complex (TSC) 2 on chromosome 16p13.3, encoding tuberin which is thought to be essential for p27(Kip1) to regulate the cell cycle. In this study, we conducted to examine whether overexpression of TSC2 can affect the growth of oral cancer cells which have different expression level of p27(Kip1) protein. We constructed an expression vector containing sense-oriented rat TSC2 cDNA with pcDNA3.1. We transfected oral cancer cells, B88t (high expression of p27(Kip1) protein) and HI (low expression of p27(Kip1) protein) with the sense expression vector to up-regulate the expression of TSC2 gene. Overexpression of TSC2 exerted the growth inhibitory effect of B88t and HI in vitro and in vivo. These findings suggest that overexpression of TSC2 may exert the antitumor effect on oral cancer cells whether they have high expression of p27(Kip1) protein or not.