A Gene Expression Signature for Chemoradiosensitivity of Colorectal Cancer Cells

In this study, we use cancer cell lines to investigate the molecular differences between resistant and responsive colorectal cancer cells. Since the treatment of patients with locally advanced rectal cancers involves chemoradiotherapy (CT/RT), we specifically implemented an in vitro protocol that mimics this clinical setting. We anticipate that this analysis will unveil relevant pathways underlying the resistance of rectal cancers to CT/RT, and enable the identification of novel therapeutic target genes. 12 colorectal cancer (CRC) cell lines were obtained from the ATCC, and cultured in the respective tissue culture medium as recommended by the ATCC: Caco-2, HT-29, LS411N, LS513, LS1034, SW403, SW480, SW620, SW837, SW1116, SW1463, and WiDr. For each cell line, RNA was independently isolated at three different passages, and hybridized to a gene expression array. Accordingly, there are three biological triplicates per cell line. Additionally, SW480 (triplicate), SW837 (triplicate), and Caco-2 (duplicate) were cultured in RPMI.