MicroRNAs (miRNAs) are a group of small non-coding RNAs that directly bind to the 3'-untranslated-region (3'UTR) of mRNA, thereby blocking gene expression post-transcriptionally. Accumulating evidence prove that microRNA-873 (miR-873) functions as a promoter or suppressor in various cancers, while whether it affects the progression of colorectal cancer (CRC) is yet unknown. Here we found that miR-873 was downregulated in human CRC clinical samples, mouse CRC specimens and cell lines with high metastatic potential. We also demonstrated that low miR-873 expression was closely associated with poor prognosis of CRC. Overexpressing miR-873 suppressed proliferation and metastasis of CRC cells both in vitro and in vivo, while inhibiting miR-873 expression promoted the proliferation, migration and invasion in vitro. Moreover, miR-873 exerted its function by perturbing the ERK-CyclinD1 pathway and the epithelial-mesenchymal transition (EMT) process. Furthermore, we revealed that miR-873 acted as a tumor-suppressive microRNA by directly binding to the 3'UTRs of ELK1 and STRN4 and suppressed their expression. Our study uncovered an inhibitory role of miR-873 in CRC progression and might provide a promising marker for CRC diagnosis and prognosis.
Keywords: ELK1; STRN4; colorectal cancer; metastasis; miR-873.