MiR-10a Involved In Metastasis Of Colon Cancer By Targeting Matrix Metalloproteinases14(MMP14)

Objective:The process of metastasis is a cascade of linked sequential steps involving multiple regulated genes, the crypticity and predictability is the most insidious and life-threatening aspects of cancer. Our understanding of the processes of metastases has improved, and the discovery of microRNAs (miRNAs) explores a new way to find the answer. miRNAs are a new family of small RNA molecules, which are proven to negatively regulating certain genes containing complementary sequences in3’untranslated regions. In several cases, miRNAs have been shown to affect target genes that are involved in the control of cell proliferation and apoptosis, display similar function of oncogenesis regulators. Bioinformatics even support that the miRNAs differentially expressed in normal tissues and cancers targeting genes contribute to the progression of metastasis. The objective of this paper is to find a miRNA contribute to the progression of metastasis, and reveal the mechanism through confirmation of target genes.Methods:It was proven that miR-10a is upregulated in low metastasis conlon cancer. By invasion assay, we measured the invasion ability of low metastasis conlon cancer cell SW480after miR-10a was blocked. Target genes of miR-10a predicted through Bioinformatics were analyzed to find genes involved in the process of metastasis. By EGFP reporter assays, the predicted gene was verified experimentally, by RT-PCR and Western Blot assays the mRNA and protein levels of target gene were tested. To explore whether miR-10a can inhibit the metastasis of colon cancer in vivo, intrasplenic injection of SW620cells was performed on nude mice, and the metastasis potential was evaluated by examining the metastasis nodules on liver surface.Results:The invasion ability of SW480was elevated dramatically after miR-10a was blocked. MMP14was the putative target gene of miR-10a predicted by computational target prediction algorithm, and it was reported to play critical roles in metastasis. EGFP reporters carrying the3’ untranslated regions of MMP14can be inhibited by miR-10a whether endogenous or transfected. Expression level of MMP14increased when miR-10a was inhibited in SW480or undetectable in SW620. Fewer liver metastasis were detected in nude mice after miR-10a were transected into SW620.Conclusion:We confirmed that miR-10a is a key regulator of metastasis in colon cancer. MMP14, which involved in metastasis by degrading extracellular matrix, promoting tumour growth and angiogenesis was identified experimentally as a target gene of miR-10a. In vivo assessment of metastasis potential by intrasplenic inoculation suggested that miR-10a could inhibit the formation of liver metastasis in some degree.