The expression of cytochrome P450 2C19 (CYP2C19) and ATP-binding cassette, sub-family B member 1 (ABCB1) were significantly lower in the EREC group (6/15) compared to the NREC group (9/15) in colorectal cancer with metachronous liver metastasis and with serum CEA >5 ng/ml.
Furthermore, expression of the multi-drug resistance gene PGY-1 and the carcinoembryonic antigen (CEA) gene were elevated in the liver metastases compared with the spleen tumors and cultured cells.
In this study we report detection of mdr1 gene expression in the liver metastases of 7/11 patients with colon carcinoma and characterise the MDR phenotype associated with a panel of 19 human colon carcinoma cell lines.