Expression and purification of human TAT-p53 fusion protein in Pichia pastoris and its influence on HepG2 cell apoptosis

P53 is an attractive target in molecular cancer therapeutics because of its critical role in regulating cell cycle arrest and apoptosis. The limitations in the development of p53-based cancer therapeutic strategy include its inefficient transmission through cell membrane of tumor cells and low protein yields in the expression system. In the present study, p53 was fused with HIV TAT protein, which can cross cell membranes, and expressed by Pichia pastoris. Stable production of Tat-p53 was achieved. After being transduced with Tat-p53 protein, the growth of cancer cell line, HepG2, was inhibited by increased apoptosis in culture. This expression system could thus be utilized to produce human Tat-p53 fusion protein.