Roles of microRNAs and their target genes in predicting chemoradiotherapy efficacy of rectal cancer

Objective: MicroRNAs (miRNAs) play important roles in the chemoradiotherapy efficacy of rectal cancer (RC). This study aimed to screen the chemoradiotherapy-associated microRNAs and their target genes of RC through bioinformatics approaches in order to promote the fundamental study of RC chemoradiotherapy. Methods: The chemoradiotherapy-associated microRNAs were manually searched through the published papers via PubMed and its target genes were identified by comprehensively analyzing these public data of microRNA-mRNA and gene expression profiles. Both gene ontology (GO) and pathway analysis of the target genes were performed by DAVID and IPA programs, respectively. Results: A total of 38 microRNAs were collected from PubMed, and 3545 putative target genes were inferred from the integrated microRNA-mRNA associations, among them, 131 were differentially expressed (DE) (P < 0.05) in the selected gene expression profile (GSE35452). The GO and pathway enrichment analyses indicated that the DE genes were closely involved in the responses of chemoradiotherapy of RC. Conclusions: These microRNAs and their regulated DE genes may contribute to the molecular mechanism of the differential efficacy of RC chemoradiotherapy, which may provide a theoretical reference for predicting the response of RC to chemoradiotherapy. (authors)