[Analysis of gene expression patterns in an irinotecan-resistance colon cancer cell by cDNA microarray].

OBJECTIVE: To study the mechanism of irinotecan-resistant colon cancer by analyzing the differential gene expression patterns with cDNA microarray. METHODS: Total RNA was purified from irinotecan-sensitive colonic cancer cell line, SW480 and its irinotecan-resistance cell line, SW480/CPT. The cRNA retro-transcribed from RNA were labeled with Cy3 fluorescence as probes. The probes were hybridized with Agilent gene chips and the fluorescence images of the chips were obtained with Axon 4000B scanner as well as analyzed with Genepix 3.0 software. The microarray results were confirmed by reverse transcription-polymerase chain reaction. RESULTS: Of the 1598 genes with altered expressions, there were 911 up-regulated genes and 687 down-regulated genes. Glutathione S-Transferase (GST) isoenzyme family GSTA such as GSTA1, GSTA2, GSTA3 and GSTA5 were significantly up-regulated. The expression levels of many Zinc finger protein family members (ZNF) were also differentially regulated. CONCLUSION: GSTA and ZNF subunit genes might play an important regulation role in the irinotecan resistance of colon cancer.