MiR-3622a-3p acts as a tumor suppressor in colorectal cancer by reducing stemness features and EMT through targeting spalt-like transcription factor 4

Abstract

Background MicroRNAs are a class of small non-coding RNAs which act as oncogenes or tumor suppressors through targeting specific mRNAs. MiR-3622a-3p is found to be decreased in colorectal cancer (CRC) in TCGA database and there are few reports about the role of miR-3622a-3p in cancers. Our research aimed to explore the effect of miR-3622a-3p in CRC. Methods MiR-3622a-3p expression in CRC tissues and cells was examined by qRT-PCR. The effect of miR-3622a-3p on proliferation, apoptosis, cell cycle, migration and invasion of CRC cells were investigated by a serious of biological function assays. We performed dual luciferase assay to confirm the interaction between miR-3622a-3p and its potential target gene. Western blot was carried out to determine the effect of miR-3622a-3p on stemness features and EMT. Tumor xenograft model and in vivo metastasis model were established using nude mice. The CRC organoid model was constructed with fresh CRC tissues. Results MiR-3622a-3p was down-regulated in CRC tissues and cells. Biological function assays revealed that miR-3622a-3p could inhibit the malignant biological properties of CRC. MiR-3622a-3p suppressed stemness features and EMT of CRC cells by SALL4 mRNA degradation. The results of animal experiments showed miR-3622a-3p could inhibit CRC cell proliferation and metastasis in vivo . The growth of organoids was also suppressed by miR-3622a-3p. Conclusions Taken together, the results of our study indicate miR-3622a-3p exerts antioncogenic role in CRC by downregulation of SALL4. The research on miR-3622a-3p might provide a new insight into treatment of CRC.