The Biological Effects and Mechanisms of Foxp3 in Lewis Lung Cancer Cell

Forkhead box P3 (Foxp3) has been considered to be the key regulator for the development and function of CD4+CD25+ Treg cells(regulatory T cells, Tregs). The high levels of Tregs in peripheral blood and tumor tissues have been reported in cancer patients and have been closely related to worse prognosis. Recent reports showed the expression of Foxp3 were not only in Tregs, but also in tumor cells. Foxp3 expression in lung cancer cells and its functions have not been reported now. We constructed the recombinant plasmid pcDNA3.1-Foxp3 and transiently transfected mouse lewis lung carcinoma (LLC) cells to investigate the biological effects and mechanisms of Foxp3 by detecting cells proliferation, cell apoptosis and cell cycle. The results illuminated that Foxp3 protein were highly expressed in Foxp3 transfected LLC cells. Foxp3 expression in LLC significantly inhibited cell proliferation. The related mechanism for Foxp3 inhibiting cell proliferation has no relationship with cell apoptosis, but has relationship with cell cycle. Foxp3 transfected LLC cells were arrested in the G0-G1 phase. In conclusion, Foxp3 in LLC inhibited cell proliferation and cell blocking in the G0-G1 phase might be its main mechanism.