Synergistic use of epidermal growth factor and 5-fluorouracil for the treatment of human colorectal cancer in BALB/C nude mice subcutaneous xenograft model

Abstract

To investigate the synergistic effect of epidermal growth factor(EGF) and 5-fluorouracil for the treatment of human colorectal cancer in BALB/C nude mice subcutaneous xenografts model. Human colorectal cancer Caco-2 cells were transplanted into the subcutaneous tissue of nude mice. The tumor growth was followed up every 4 days after treatment, and estimated tumor weight, tumor growth curve, and results from histologic examination were used to evaluate the effects of EGF on the growth of tumors. Proliferation of the tumor cells was estimated by PCNA labeling index. The combined use of EGF and 5-fluorouracil significantly inhibited the growth of colorectal cancer xenografts in nude mice with the inhibitory rate of 57.05% which was higher than 5-fluorouracil did (40.97%)(P<0.05). No pathologic changes were observed in organs. PCNA labeling index was elevated in combined group which implied more tumor cells reentry cell cycle. Epidermal growth factor, which may recruit colorectal cancer cells into activated phases of the cell cycle, can enhance the sensitivity of colorectal cancer cell Caco-2 to 5-fluorouracil.