ABSTRACT
BACKGROUND AND AIMS: Although colon cancer has a decreasing incidence trend in Europe, because of its still high frequency and not fully understood pathogenesis, this malignancy still remains a subject of intense research. The aim of this study was to investigate the role of microRNA-194 and microRNA-1228 in colon cancer proliferation. METHODS: RNA was extracted from patients with colon cancer with or without advanced disease and microRNA expression levels were determined through qRT-PCR. Assays were performed on HCT116 cell line and included qRT-PCR, western blotting and cell counting. RESULTS: We observed that both microRNAs 194 and 1228 were altered in patients with colon cancer compared with healthy individuals. We observed a lower expression of both microRNA-194 and microRNA-1228 in patients with advanced colon cancer. To validate their pathogenetic role we performed viability and invasion assays on HCT116 cell line transfected with mimics or inhibitors of the mentioned microRNAs, with observable changes in viability and invasion. Furthermore, to determine the altered signaling induced by these microRNAs, we performed western blotting for phospho S6 on HCT116 cells transfected with mimic and inhibitor of the above-mentioned microRNAs with observable differences. CONCLUSION: In the current study we have shown that both microRNA-194 and microRNA-1228 alteration was correlated with the presence of advanced colon cancer, a fact that was further validated in vitro through an invasion assay. Moreover, we have also shown that their effect might be mediated through phospho S6 expression.
Subject(s)
Adenocarcinoma/blood , Biomarkers, Tumor/blood , Cell Proliferation , Circulating MicroRNA/blood , Colonic Neoplasms/blood , MicroRNAs/blood , Ribosomal Protein S6 Kinases/metabolism , Adenocarcinoma/genetics , Adenocarcinoma/pathology , Biomarkers, Tumor/genetics , Cell Movement , Circulating MicroRNA/genetics , Colonic Neoplasms/genetics , Colonic Neoplasms/pathology , Female , HCT116 Cells , Humans , Male , MicroRNAs/genetics , Middle Aged , Neoplasm Invasiveness , PhosphorylationABSTRACT
BACKGROUND AND AIMS: Worldwide, colorectal cancer (CRC) is the third most common cancer in men and second in women. The aim of the current study was to identify whether the miR-375 is indeed down-regulated in metastatic CRC and if it could be considered as a potential minimally invasive prognostic biomarker for CRC. METHODS: Exosomes were isolated and characterized from patients with liver metastasis from CCR. The characterization of exosome was performed using TEM/SEM. HCT116 cells were treated with miR-375 mimic, NSM and miR-375 inhibitor. Functional assays included cell counting assay for 14 days, Matrigel invasion assay, apoptosis assay by flow cytometry using Annexin V-FITC, RT-PCR and Western blotting. RESULTS: Increased proliferation potential was proven for the cells transfected with miR-375 inhibitor, while the miR-375 mimic decreased the cell number. The cells transfected with the miR-375 inhibitor are aggressive and cross the membrane; 3.84% of the cells transfected with the miR-375 inhibitor entered apoptosis, while 6.45% of those transfected with the non-specific mimic were in programmed cell death, less than those transfected with the microRNA. RT-PCR for Bcl-2 expression showed that Bcl-2 is down-regulated for miR-375 inhibitor and up-regulated for the miR-375 mimic, a result confirmed by Western blotting. CONCLUSION: The present study brings to the forefront new data that suggest miR-375 as a new player in controlling the pathways responsible for inhibiting the natural history of CRC tumor cells, via the Bcl-2 pathway.