Study the anti-tumor effect and its mechanism of arsenic trioxide combined with fluorouracil on human large intestine carcinoma cell

Objective To study the anti-tumor effect of arsenic trioxide(As2O3) combined with fluorouracil(5-Fu) on the human large intestine carcinoma cell line CoLo-320 and explore its mechanism. Methods In vitro, human coloncarcinoma cell line CoLo-320 was treated by As2O3 and 5-Fu in various concentrations respectively alone or in combination, and then cell growth was assayed by MTT method, apoptosis, morphological and cell cycle changes were observed by acridine orange(AO)/ethidiumbromide(EB) fluorescent staining, DNA gel electrophoresis, electron microscopy detection and flow cytometry, and the expression of apoptosis-related genes were analyzed by immunohistochemical staining method. Results Compared with As2O3 or 5-Fu individual drug groups, As2O3 combined with 5-Fu obviously increased the inhibition rate and apoptosis rate of CoLo-320 cell, and the cell ratio of S phase was decreased with bcl-2 gene expression down-regulated, and Bax and Fas gene expression up-regulated. Conclusions Arsenic trioxide combined with 5-Fu may obviously increase the anti-large intestine carcinoma effect,and maybe its mechanism is increasing apoptosis-inducing effect which is regulated by several genes and enhancing the anti-tumor effect of cell cycle specific agent combined with cell cycle regulatory agent.