Drug repurposing in colorectal cancer by using transcriptomic data

Colorectal cancer (CRC) is one of the most fatal cancer types that people suffer from worldwide. In this study, we aimed to reveal the candidate drugs that may be usable in the treatment of CRC via a very popular approach known as drug repurposing (drug repositioning) and computational biology methods. Firstly, differentially expressed genes (DEGs) were identified in CRC via analyzing transcriptomic data. Then, differentially coexpressed gene modules were identified and prognostic significance of these module genes in CRC was demonstrated. Finally, based on the gene modules we uncovered, various treatment candidates that may alter the course of CRC were identified. These candidates include drugs or small molecules which were studied in experimental/clinical studies to demonstrate the effects on tumor growth or not used/studied originally in the treatment of CRC. In our study, we revealed a novel, differentially co-expressed, highly interconnected, and co-regulated prognostic gene module in CRC consisting of twenty two genes. We suggest fifteen drugs or small molecules comprising gallic acid, valinomycin, cysteamine, AZD8055, BRDK81473043, tyrphostin AG1478, BRD-A17065207, dovitinib, trametinib, HDAC6 inhibitor ISOX, AS605240, 480743.cdx, BRD-K03829970, L-6307 and NVP-TAE684 as repurposing candidates for CRC. We present HDAC6 inhibitor ISOX, AS605240, 480743.cdx, BRDK03829970, L-6307, and NVP-TAE684 as novel repuposing candidates whose anticarcinogenic effects on CRC tumorigenesis have not been investigated before. Clinical investigation of our findings is important in terms of creating new treatment options for CRC. Keywords: colorectal cancer, drug repurposing, transcriptomic data