Comparison of putative circulating cancer stem cell detection between the hepatic portal system and peripheral blood in colorectal cancer patients

ABSTRACT

PURPOSE: The present pilot study was conducted to detect putative cancer stem cell (CSC) from the hepatic portal system and peripheral blood in the colorectal cancer patients and to compare them to healthy donor and diverticulitis patients. METHODS: Laboratory study was performed to identify the expression of cell surface markers, epithelial cell adhesion molecule (EpCAM), cytokeratin (CK) 18, CK20, CD44, and CD133, on several colon cancer cell lines. Clinical pilot study was conducted to detect putative circulating CSC as EpCAM+CD133+ cell in colorectal cancer (n = 10), diverticulitis (n = 5), and four healthy donors, by using flow cytometry. Blood was drawn from the hepatic portal system and peripheral vein. RESULTS: On laboratory study, EpCAM was expressed in whole colon cancer cell lines, and CD44 and CD133 were simultaneously expressed in 50% of the cell lines with stemness phenotype, but CK18 and CK20 were not expressed in most of the cell lines. On clinical study, the mean EpCAM+CD133+ cell counts of 11.6/105 in the hepatic portal system were somewhat lower than 15.4/105 in peripheral vein (P = 0.241). As for diverticulitis patients, EpCAM+CD133+ cells were also detected to have steeper dropped to near zero, after the surgery. CONCLUSION: The numbers of putative CSC were not statistically different between the detection sites of the portal vein and peripheral vein in the colon cancer patients. Therefore, we may not have benefitted by getting the cells from the hepatic portal system. In addition, the CD133+EpCAM+ cells in the colon cancer patients might contain normal stem cells from cancer inflammation similar to diverticulitis.