Integrative Transcriptomic Network Analysis of Butyrate Treated Colorectal Cancer Cells.

Diet-derived histone deacetylase inhibitor (HDACi), butyrate, alters global acetylation and consequently global gene expression in colorectal cancer (CRC) cells to exert its anticancer effects. Aberrant microRNA (miRNA) expression contributes to CRC development and progression. Butyrate-mediated modulation of microRNA (miRNA) expression remains under-investigated. This study employed a systems biology approach to gain a comprehensive understanding of the complex miRNA-mRNA interactions contributing to the butyrate response in CRC cells. Next-generation sequencing, gene ontology (GO) and pathway enrichment analyses were utilized to reveal the extent of butyrate-mediated gene regulation in CRC cells. Changes in cell proliferation, apoptosis, the cell cycle and gene expression induced by miRNAs and target gene knockdown in CRC cells were assessed. Butyrate induced differential expression of 113 miRNAs and 2447 protein-coding genes in HCT116 cells. Butyrate also altered transcript splicing of 1591 protein-coding genes. GO, and pathway enrichment analyses revealed the cell cycle to be a central target of the butyrate response. Two butyrate-induced miRNAs, miR-139 and miR-542, acted cooperatively with butyrate to induce apoptosis and reduce CRC cell proliferation by regulating target genes, including cell cycle-related EIF4G2 and BIRC5. EIF4G2 RNA interference mimicked the miR-139-mediated reduction in cell proliferation. The cell cycle is a critical pathway involved in the butyrate response of CRC cells. These findings reveal novel roles for miRNAs in the cell cycle-related, anticancer effects of butyrate in CRC cells.