The Identification And Characterization Of Cancer Stem Cells-Like Properties From CD133+ Cells Separated From Hepatocellular Carcinoma Tissue Specimens

Background and Objective Hepatocellular carcinoma(HCC) is one of the most common pathological types of primary liver cancer, with a rising incidence worldwide. The cancer stem cell (CSC) concept suggests that there are a subpopulation of cancer cells with stem cell properties in the bulk of the tumor mass, called CSCs, which are associated with proliferation, recurrence, metastasis and resistance to chemotherapy or radiotherapy of cancer. Accumulating evidences have shown that CSCs exist in tumor. The study is aimed to investigate whether CD133+ cells separated from HCC tissue specimens possess the CSCs-like properties.Methods Twenty-five fresh liver tumor and adjacent nontumor tissue specimens resected from HCC patients were respectively digested into single liver cancer cells and single liver cells,partial of which were analyzed for the proportion of CD133 expression using flow cytometry and the other single liver cancer cells were primarily cultured. Using flow cytometry, the CD133+ and CD133- cells were sorted from the obtained liver cancer cells and then were comparably characterized the properties of cancer stem cells by colony-forming assay, sphere formation assay and xenograft tumorigenicity assay.Results We successfully cultured liver cancer cells with passaged ability by enzyme digestion method. Expression of CD133 in 25 HCC tissue specimens ranged from 3.8% to 8.3%, comparing with nontumor liver tissues ranging from 0.1% to 0.4%, and the difference was statistically significant (t=17.12, P<0.001). When compared with CD133- cells, CD133+ cells not only possessed the preferential ability to form tumor colony in vitro((25.2±0.8)%vs(7.6±0.8)%, t=81.95, P<0.001)but also form tumor spheroids in vitro((20.3± 0.6)%vs(12.5±1.4)%,t=68.17, P<0.001), had a greater ability to form xenograft in nude mice.Conclusion1、CD133+ cells isolated from HCC tissue specimens account for only a small fraction in the bulk of the tumor mass.2、CD133+ cells isolated from HCC tissue specimens possess the CSCs-like properties.