Abstract: Objective To study the inhibitory effects of Chinese yam combined with tegafu on colon cancer HT-29 cells in vivo and in vitro. Methods The changes of cell morphology were observed by the method of adopting 2×2 factorial designs, after HT-29 colon cancer cells were treated with physiological saline containing dimethyl sulfoxide (blank control),tegafur (36 mg/L) and Chinese yam (125 mg/L). MTT method was used to detect the proliferation of tumor cells, and flow cytometry was used to detect the expression of tumor stem cells (CD133+ cells). The nude mouse model of colon cancer HT-29 cells was established. The treatment was given in the above method, and the tumor inhibition rate was calculated. The VEGF positive rate of the tumor was detected by immunohistochemistry. Results The inhibited proliferation of colon cancer HT-29 cells was significantly higher in the synergistic group than that in Chinese yam group and tegafur group, and the inhibitory rates were higher in the three treatment groups than that of blank control group. The proportion of CD133+ cells was significantly lower in HT-29 cells in the synergistic group compared with that of the Chinese yam group and the tegafur group, and which was lower in these three groups than that of the blank control group. After the treatment in three treatment groups, the tumor quality and VEGF positive rate were significantly lower than those of the blank control group, and which was lower in the tegafur + Chinese yam group than that of Chinese yam group and the tegafur group. Conclusion Chinese yam combined with tegafu can inhibit the proliferation of colon cancer HT-29 cells and their stem cells.

Key words: colonic neoplasms, HT-29 cells, DIOSCOREA OPPOSITA, mice, inbred BALB C, neoplasms,experimental, vascular endothelial growth factors, tegafur