ABSTRACT
BACKGROUND:EpCAMhighCD44+ colon cancer stem cels have been isolated in recent years, and most of them are related to the study of isolating tumor stem cels in colorectal cancer cel lines. There are less reports on the function of colon cancer stem cels. OBJECTIVE:To isolate, screen and culture colon cancer stem cels from colorectal carcinoma tissues and to explore the protein expression and biological characteristics of colon cancer stem cels. METHODS: The primary cels were isolated from the colon cancer tissues. EpCAMhighCD44+ cels were detected and sorted by flow cytometry. Then, these cels were cultured in serum-free medium. After the cels were replanted subcutaneously into the mice, we observed the daily performance and tumor growth in the mice. When the tumor diameter was above 1 cm, tumor tissues were taken for immunohistochemical testing. The growth of EpCAMhighCD44+ cels cultured in the serum-free medium was observed; expressions of neutral epithelial mucin and CK-20 in EpCAMhighCD44+ cels were detected. RESULTS AND CONCLUSION: EpCAMhighCD44+ colon cancer stem cels were detected in the colon cancer tissues, and the proportion of EpCAMhighCD44+ cels in primary colon cancer cels was 1.7%-38%. After 24 hours of serum-free culture, there were a few of smal suspended cel spheres which were incompact. After 21 days, dense cel spheres with uniform size were found. The formation of transplanted tumor was found in the nude mice. Hematoxylin-eosin staining showed the transplanted tumor had the typical characteristics of colon cancer cels. The expression of neutral epithelial mucin and CK-20 was observed in al the transplanted tumors. Additionaly, the proliferation of EpCAMhighCD44+ cels could be promoted by 5-fluorouracil (10, 1, and 0.1 PPC) with time. These findings indicate that EpCAMhighCD44+ colon cancer stem cels in the colon cancer have a certain ability of proliferation, regeneration, differentiation, tumor formation and chemotherapy resistance.