Expression Patterns for TETs, LGR5 and BMI1 in Cancer Stem-like Cells Isolated from Human Colon Cancer

Colon tumor is generated and maintained by a small subset of chemo-resistant cancer cells known as Cancer Stem-like Cells (CSCs) that are able to self-renew and differentiate into various cell types within the cancer milieu. CSCs are identified through expression of CD133 that is the most important surface marker of these cells. Epithelial Cell Adhesion Molecule (EpCAM) is another colon CSCs marker. Other markers that are probably involved in colon tumorigenesis are Leucine-rich repeat-containing G-protein-coupled Receptor 5 (LGR5), B cell-specific Moloney murine leukemia virus insertion site 1 (BMI1) and Ten-Eleven Translocations (TETs).

Here, mRNA expression rates of LGR5, BMI1 and TETs were surveyed by real-time PCR. After collection and digestion, colon samples were used to isolate CD133 and EpCAM positive CSCs through evaluation of AC133 EpCAM by Magnetic Activated Cell Sorting (MACS) and flow cytometry. Real-time PCR was carried out for assessing expressions of LGR5, BMI1 and TETs.

High expressions for LGR5, BMI1, TET1 and TET2 in the CD133 and EpCAM positive CSCs (p≤0.05 vs. non-CSCs) were found. TET3, however, showed no significant changes for mRNA expression in the CSCs.

In conclusion, high mRNA expressions for LGR5, BMI1, TET1 and TET2 in the CD133 and EpCAM positive CSCs may be a useful criterion for better identification of the cells involved in colon cancer in order to specify therapeutic targets against this type of cancer.