Analysis of the Correlation between CD133 Expression on Human Colorectal Adenocarcinoma Cells HT-29 and Their Resistance to Chemotherapeutic Drugs.

A correlation was found between chemoresistance of HT-29CD133+ and HT-29CD133- sublines obtained after cell sorting and high expression of CD133. On the other hand, knockout of the PROM1 gene and, as a consequence, the absence of CD133 expression did not increase the sensitivity of tumor cells to chemotherapy, which indicates the absence of a direct effect of CD133 on the formation of chemoresistance in colorectal cancer cells. Variants of the HT-29 line with complete or partial knockout of the PROM1 gene were equally sensitive to protein kinase inhibitors sorafenib and sunitinib. Notably, the highest resistance to mTOR inhibitors, temsirolimus and everolimus, was shown by cells with complete knockout of the PROM1 gene (KO-HT-29 (P1)). These findings suggest that CD133 is associated with the chemoresistance of colorectal cancer cells, but is not involved in its formation.