Purpose: To evaluate chemosensitivity and its correlation with expression levels of the multidrug resistant transporter (MDR1) and the multidrug resistance-associated proteins 1 and 2 (MRP1, MRP2) mRNA in human colorectal adenocarcinomas.
Methods: Colorectal adenocarcinomas were obtained as surgical samples from 25 patients. The chemosensitivity of 12 anticancer drugs was assessed by the collagen gel droplet embedded culture drug sensitivity test (CD-DST). The expression levels of MDR1, MRP1, and MRP2 mRNA in colorectal adenocarcinomas were also evaluated by real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR).
Results: The chemosensitivity was successfully evaluated for 16 of 25 patients, and the anticancer drugs were effective against the samples showing a relatively high growth rate. Gemcitabine hydrochloride was found to be more promising than those often prescribed for the treatment of colorectal adenocarcinoma. There was no correlation of the mRNA expression levels of MDR1 and MRP1 with the chemosensitivity of any anticancer drugs tested, but mitomycin C was found to be more effective for the colorectal adenocarcinoma with relatively high expression of MRP2 mRNA.