Multi-microarray identifies lower AQP9 expression in adjuvant chemotherapy nonresponders with stage III colorectal cancer

• Gene expression and miRNA arrays of nonresponders’ and responders’ fresh-frozen tissues were compared.
• We find 59 genes and 17 miRNAs differentially expressed by at least two folds.
• Expression of AQP9, SATB2, and WIF1 are lower in the nonresponders and modulated by differentially expressed miRNAs.
• RT-PCR validates lower expression of AQP9, but not the other two genes, in nonresponders.

Approximately 25% of stage III colorectal cancer patients do not benefit from standard adjuvant chemotherapies. To identify biomarkers for nonresponders, fresh-frozen tissues of 19 nonresponders and 16 responders were analyzed with gene expression and microRNA arrays. Fifty-nine genes and 17 miRNAs were differentially expressed by at least two folds. AQP9, SATB2, and WIF1 were simultaneously lower expressed in the nonresponders and modulated by the differentially expressed miRNAs. RT-PCR validated the differential expression of AQP9 (p = 0.035). In conclusion, lower AQP9 gene expression is related with non-response to adjuvant chemotherapy, showing potential as predictive marker and therapeutic target.