E-Cadherin in Colorectal Cancer: Relation to Chemosensitivity

The conventional chemotherapy of colorectal cancer with irinotecan, 5-fluorouracil, and oxaliplatin remains one of the front-line treatments worldwide. However, its efficacy is quite low. Recently studies of the epithelial-mesenchymal transition (EMT) have become the focus of investigations into the cause of chemoresistance in several types of cancer, including colorectal cancer. The data about the role of EMT in chemosensitivity are controversial.

Human colon adenocarcinoma cell lines HT29 and HCT116 and 14 primary short-term cultures established from patient tumors were used. The chemosensitivity to irinotecan, 5-fluorouracil, and oxaliplatin was assessed using the (4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test. Immunocytochemistry, immunohistochemistry, and Western blot test were used to investigate the E-cadherin expression, the loss of which is a major hallmark of EMT.

Elevated chemosensitivity of the cell line with EMT phenotype, HCT116, was demonstrated. Increased chemosensitivity was revealed in HT29 cell line upon EMT induction. E-cadherin-positive short-term cultures were more resistant to all the drugs tested, whereas each of E-cadherin-negative cultures showed sensitivity to at least one drug. The statistically significant dependency of cells viability on the E-cadherin expression (P < .04) was demonstrated on the short-term cultures using 2 concentrations of each drug.

The data obtained may serve as a basis for the analysis of colon cancer chemosensitivity using short-term cultures and the assay of E-cadherin expression.