Tumor suppressive role of miR-33a-5p in pancreatic ductal adenocarcinoma cells by directly targeting RAP2A.

BACKGROUND: The suppressive effects of miR-33a-5p have been reported in colorectal cancer and lung cancer. However, the functional role of miR-33a-5p in pancreatic ductal adenocarcinoma (PDAC) has not yet been elucidated. METHODS: The expression of miR-33a-5p was determined using reverse-transcription quantitative PCR (RT-qPCR) in PDAC tissues and cell lines. The association between miR-33a-5p expression and clinical categorical parameters was analyzed by the chi-square test. Cell proliferation was analyzing by Cell Counting Kit -8 (CCK-8) assay. Transwell assay was utilized to assess cell migration and invasion. The interactions between miR-33a-5p and RAP2A were verified by luciferase reporter assay, RT-qPCR, western blot analysis and RNA immunoprecipitation (RIP) assay. RESULTS: Here, we observed for the first time that miR-33a-5p expression level was significantly decreased in PDAC tissues and cell lines. There was a significant association between decreased miR-33a-5p expression and TNM stage or lymph node metastasis. Overexpression of miR-33a-5p significantly inhibited SW1990 and PANC-1 cell proliferation, migration and invasion. Knockdown of miR-33a-5p remarkedly promoted cell proliferation, migration and invasion in BxPC-3 and ASPC-1. Mechanistically, RAP2A was confirmed as the target of miR-33a-5p in PDAC cells. Moreover, RAP2A overexpression abolished miR-33a-5p-mediated suppressive effects on SW1990 and PANC-1 cells. CONCLUSIONS: Taken together, these results suggest that miR-33a-5p exerted tumor suppressive effects on PDAC cells by targeting RAP2A, which might provide a new theoretical basis for the clinical treatment of PDAC.

Integrated analysis of potential pathways by which aloe-emodin induces the apoptosis of colon cancer cells.

BACKGROUND: Colon cancer is a malignant gastrointestinal tumour with high incidence, mortality and metastasis rates worldwide. Aloe-emodin is a monomer compound derived from hydroxyanthraquinone. Aloe-emodin produces a wide range of antitumour effects and is produced by rhubarb, aloe and other herbs. However, the mechanism by which aloe-emodin influences colon cancer is still unclear. We hope these findings will lead to the development of a new therapeutic strategy for the treatment of colon cancer in the clinic. METHODS: We identified the overlapping targets of aloe-emodin and colon cancer and performed protein-protein interaction (PPI), Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses. In addition, we selected apoptosis pathways for experimental verification with cell viability, cell proliferation, caspase-3 activity, DAPI staining, cell cycle and western blotting analyses to evaluate the apoptotic effect of aloe-emodin on colon cancer cells. RESULTS: The MTT assay and cell colony formation assay showed that aloe-emodin inhibited cell proliferation. DAPI staining confirmed that aloe-emodin induced apoptosis. Aloe-emodin upregulated the protein level of Bax and decreased the expression of Bcl-2, which activates caspase-3 and caspase-9. Furthermore, the protein expression level of cytochrome C increased in a time-dependent manner in the cytoplasm but decreased in a time-dependent manner in the mitochondria. CONCLUSION: These results indicate that aloe-emodin may induce the apoptosis of human colon cancer cells through mitochondria-related pathways.

Upregulation of miR-874-3p decreases cerebral ischemia/reperfusion injury by directly targeting BMF and BCL2L13.

Ischemic stroke represents a major cause of adult physical disability, which is triggered by cerebral artery occlusion induced blood flow blockage. MiR-874-3p has been reported to be down-regulated in the brain injury induced by ischemia-reperfusion (I/R), but the direct evidence associated with injury of I/R remains unknown. In this study, we found that miR-874-3p levels significantly decreased in rat I/R brain induced by middle cerebral artery occlusion/reperfusion (MCAO/R) and SH-SY5Y cells following oxygen-glucose deprivation and reperfusion (OGD/R) treatment. Upregulation of miR-874-3p reduced infarct volumes and cell apoptosis in the in vivo I/R stroke model using TTC and TUNEL staining, as well as increased proliferation and inhibited apoptosis in OGD/R induced SH-SY5Y cells by CCK-8, Edu staining and flow cytometry analysis. Mechanistically, bioinformatics analysis and luciferase reporter assay confirmed BCL-2-modifying factor (BMF) and Bcl-2 family protein Bcl-rambo (BCL2L13) were the direct targets of miR-874-3p. Furthermore, BMF or BCL2L13 knockdown also provided significant protection against OGD/R induced injury, while their overexpression reversed the protective effects of miR-874-3p on SH-SY5Y cells following OGD/R. In summary, our results suggest that miR-874-3p attenuated ischemic injury by negatively regulating BMF and BCL2L13, highlighting a novel therapeutic target for ischemic stroke.