[Culture and identification of tumor stem cells from surgically resected colorectal cancer tissues].

objectiveTo obtain cancer stem cells (CSCs) from surgically resected colorectal cancer specimens and identify their stem cell characteristics.

methodsColorectal cancer tissue specimen obtained from a patient undergoing radical resection of colorectal cancer were implanted in nude mice, and the xenograft was harvested 1 month later to obtain purified tumor cells by enzyme digestion and adherent culture. The CSCs were screened by limiting dilution method and serum-free culture to identify their phenotypes. Soft agar colony assay was used to assess the proliferative ability of the CSCs and human colorectal cancer cell line SW480. The tumorigenic ability of the isolated CSCs and SW480 cells was evaluated by observing their subcutaneous tumor formation in nude mice. Western blotting and immunofluorescence assay were used to detect the immunophenotype of the CSCs and SW480 cells.

resultsThe primary cultured CSCs from clinical specimens of colorectal cancer underwent differentiation in the presence of serum in the culture. Soft agar colony formation assay showed that the CSCs had a colony formation rate above 50%, significantly higher than the rate of colorectal cancer SW480 cells (4.41%;

conclusionsCSCs can be derived by primary culture of cancer cells obtained from surgically resected colorectal cancer tissue followed by serum-free culture, and the CSCs obtained have self-renewal and differentiation abilities.