Abstract: P53 is involved in drug-resistance of carcinoma cells from multiple profiles, of which P53 improves drug-sensitivity in carcinoma cells through arresting cell cycle progression and inducing cellular apoptosis. Some special situations such as drug damages, external stresses and so on result in P53 activation, which might mediates drug-tolerance of carcinoma cells and inhibition of cellular apoptosis. Mutant P53 or disorder of P53, is also closely associated with promoting drug-tolerance of carcinoma cells. Besides above mentioned, the function of P53 mediated the resistance of tumor cells to drugs is probably flipped. P53 mediated the regulation of drug resistance in different carcinoma cells substantially presents a variety of possibilities.

Key words: P53, carcinoma cell, drug-resistance, regulation