Esophageal cancer (EC) is one of the most common aggressive malignant diseases worldwide. miR-28-5p plays important regulatory roles in many cancers including human EC. However, the molecular mechanism and potential role of miR-28-5p in EC remain uncertain. In this study, qRT-PCR and western blot analysis revealed that miR-28-5p expression was up-regulated and metastasis suppressor-1 (MTSS1) was down-regulated in EC tissues relative to matched para-cancer tissues. Cell counting kit-8 (CCK-8) assay demonstrated that miR-28-5p mimics increased cell viability, and miR-28-5p inhibitor decreased it. Flow cytometry (FCM) assay indicated that miR-28-5p mimics promoted cell cycle entry, while miR-28-5p inhibitor reduced it and induced cell apoptosis. Moreover, miR-28-5p mimics up-regulated the expressions of cyclin A, cyclin dependent kinase 2 (CDK2), cyclin D1, and cyclin E but down-regulated the expressions of cleaved caspase-3 and cleaved caspase-9, which was abolished by miR-28-5p inhibitor. Furthermore, luciferase reporter assay verified that miR-28-5p directly targeted MTSS1 3′UTR and down-regulated its expression. MTSS1 overexpression in TE-1 cells inhibited cell proliferation and promoted apoptosis induced by miR-28-5p mimics, whereas silencing of MTSS1 reversed cell progression induced by miR-28-5p inhibitor. We also demonstrated that miR-28-5p could promote esophageal tumor formation in vivo. Hematoxylin–eosin staining, immunohistochemistry, and TUNEL assays confirmed that miR-28-5p antagomir inhibited cell growth and accelerated apoptosis. Our results suggest that miR-28-5p may induce cell proliferation and suppress apoptosis to promote EC tumor formation via decreasing MTSS1 expression. Thus, miR-28-5p may be a potential target for human EC therapy.
Jun Ma,Di Zhao,Dahai Yu,Wei Song,Xiaofang Yang,Haitao Yin
Background Ginsenoside Rh2 (G-Rh2) exerts anti-tumor activity in non-small cell lung cancer (NSCLC). microRNAs (miRNAs, miRs) play pivotal roles in NSCLC. We aimed to investigate whether G-Rh2 inhibited NSCLC progression by targeting miRNA. Methods Cell viability, apoptosis and cycle were determined by Cell Counting Kit-8, 6-diamidino-2-phenylindole (DAPI) staining and flow cytometry. The potential target miRNAs of G-Rh2 were screened by real-time quantitative polymerase chain reaction (RT-qPCR). The difference in miR-28-5p expression between lung adenocarcinoma (LUAD) tissues and normal tissues or lung squamous cell carcinoma (LUSC) tissues and normal tissues was retrieved from TCGA-LUAD and TCGA-LUSC, respectively. Kaplan–Meier Plotter was conducted to analyze the survival rate for different serine/threonine-protein kinase 4 (STK4) expressions with different prognostic risks. immunohistochemistry of STK4 expression in non-tumor and tumor tissues was analyzed from the HPA database. RT-qPCR and Western blot were adopted for detecting mRNA and protein expression. TargetScan V7.2, miRanda and PITA were adopted for predicting targets of miR-28-5p, overlapped genes were subjected to GO analysis. The interactions of miR-28-5p-Wnt and miR-28-5p-STK4 were detected by TOP/FOP luciferase reporter assay and dual luciferase reporter assay, respectively. Results Current study observed that G-Rh2 reduced miR-28-5p expression in NSCLC cells dose-dependently. miR-28-5p was upregulated in NSCLC tissues and cells. The target genes of miR-28-5p were enriched in negative regulation of Wnt signaling. miR-28-5p inhibitor inactivated Wnt signaling, inhibited cell viability and cell cycle, while enhanced cell apoptosis of NSCLC cells by targeting STK4. G-Rh2 exerted the similar effects with miR-28-5p inhibitor by reducing miR-28-5p. G-Rh2 and miR-28-5p inhibitor exerted a synergistic effect on inhibiting NSCLC tumor growth. Conclusion In conclusion, G-Rh2 attenuates NSCLC development by affecting miR-28-5p/STK4 axis and inactivating Wnt signaling. Taken together, we project out a novel therapeutic target for NSCLC.