miR-100-3p inhibits cell proliferation and induces apoptosis in human gastric cancer through targeting to BMPR2.

BACKGROUND: miR-100 has been reported to closely associate with gastric cancer (GC) initiation and progression. However, the underlying mechanism of miR-100-3p in GC is still largely unclear. In this study, we intend to study how miR-100-3p regulates GC malignancy. METHODS: The expression levels of miR-100-3p in vitro (GES-1 and GC cell lines) and in vivo (cancerous and normal gastric tissues) were examined by quantitative real-time PCR (qRT-PCR). MTT and PE/Annexin V analyses were responsible for measurement of the effects of miR-100-3p on GC cell proliferation and apoptosis. Transwell assay with or without matrigel was used to examine the capacity of migration and invasion in GC cells. The interaction of miR-100-3p with bone morphogenetic protein receptor 2 (BMPR2) was confirmed through transcriptomics analysis and luciferase reporter assay. qRT-PCR and Western blot analyses were applied to determine the expression of ERK/AKT and Bax/Bcl2/Caspase3, which were responsible for the dysfunction of miR-100-3p. RESULTS: miR-100-3p was down-regulated in GC cell lines and cancerous tissues, and was negatively correlated with BMPR2. Loss of miR-100-3p promoted tumor growth and BMPR2 expression. Consistently, the effects of miR-100-3p inhibition on GC cells were partially neutralized by knockdown of BMPR2. Over-expression of miR-100-3p simultaneously inhibited tumor growth and down-regulated BMPR2 expression. Consistently, over-expression of BMPR2 partially neutralized the effects of miR-100-3p over-expression. Further study demonstrated that BMPR2 mediated the effects downstream of miR-100-3p, which might indirectly regulate ERK/AKT and Bax/Bcl2/Caspase3 signaling pathways. CONCLUSION: miR-100-3p acted as a tumor-suppressor miRNA that down-regulated BMPR2, which consequently inhibited the ERK/AKT signaling and activated Bax/Bcl2/Caspase3 signaling. This finding provided novel insights into GC and could contribute to identify a new diagnostic and therapeutic target.

MiR-100-3p and miR-877-3p regulate overproduction of IL-8 and IL-1ß in mesangial cells activated by secretory IgA from IgA nephropathy patients.

IgA nephropathy (IgAN) is the most common type of primary glomerulonephritis, characterized by mesangial deposition of pathogenic IgA and the injury to mesangial cells. Our previous studies indicate that secretory IgA (SIgA) plays an important role in the pathogenesis of IgAN, and miR-16 is involved in destructive process in mesangial cells mediated by the SIgA from IgAN patients. Our current study aimed to study the role of miRNAs in the effect of SIgA from IgAN patients on mesangial cells. MicroRNA microarray and cytokines assay were performed to obtain the differential microRNAs expression profile in human renal mesangial cells stimulated by SIgA from IgAN patients (P-SIgA) with the cells treated by SIgA from healthy subjects (N-SgA) as control. The microRNAs with the most significant differences in microarray analysis were validated by quantitative RT-PCR. Among them, miR-100-3p and miR-877-3p were selected to predict target gene related to cytokines detecting in this study. Fifty-six differentially expressed microRNAs were chosen and 17 microRNAs with the most prominent changes were validated. Compared with N-SIgA, P-SIgA increased the production of interleukin (IL)-1ß, IL-8, monocyte chemotactic protein-1 and transforming growth factor-ß1. In addition, we for the first time demonstrated that over-production of IL-8 induced by the SIgA was regulated by down-expression of miR-100-3p in mesangial cells. Similarly, IL-1ß over-production was regulated by down-expression of miR-877-3p. Our findings represent a pathogenic microRNAs expression profiling in human mesangial cells activated by P-SIgA. Furthermore, we provide a new explanation characterizing the molecular mechanism responsible for the regulation of IL-1ß and IL-8 production in P-SIgA-triggered mesangial cells.

METTL14 affects UVB-induced human dermal fibroblasts photoaging via miR-100-3p biogenesis in an m6A-dependent manner.

Exposure to ultraviolet radiation can lead to skin photoaging, which increases the risk of skin tumors. This study aims to investigate how microRNA m6A modification contributes to skin photoaging. This study found that skin fibroblasts exposed to a single UVB dose of 30 mJ/cm2 exhibited characteristics of photoaging. The m6A level of total RNA decreased in photoaged cells with a down-regulated level of METTL14, and overexpression of METTL14 displayed a photoprotective function. Moreover, miR-100-3p was a downstream target of METTL14. And METTL14 could affect pri-miR-100 processing to mature miR-100-3p in an m6A-dependent manner via DGCR8. Furthermore, miR-100-3p targeted at 3' end untranslated region of ERRFI1 mRNA with an inhibitory effect on translation. Additionally, photoprotective effects of overexpression of METTL14 were reversed by miR-100-3p inhibitor or overexpression of ERRFI1. In UVB-induced photoaging of human skin fibroblasts, METTL14-dependent m6A can regulate miR-100-3p maturation via DGCR8 and affect skin fibroblasts photoaging through miR-100-3p/ERRFI1 axis.

Hsa-miR-100-3p Controls the Proliferation, DNA Synthesis, and Apoptosis of Human Sertoli Cells by Binding to SGK3.

Human Sertoli cell is required for completing normal spermatogenesis, and significantly, it has important applications in reproduction and regenerative medicine because of its great plasticity. Nevertheless, the molecular mechanisms underlying the fate decisions of human Sertoli cells remain to be clarified. Here, we have demonstrated the expression, function, and mechanism of Homo sapiens-microRNA (hsa-miR)-100-3p in human Sertoli cells. We revealed that miR-100-3p was expressed at a higher level in human Sertoli cells by 10% fetal bovine serum (FBS) than 0.5% FBS. MiR-100-3p mimics enhanced the DNA synthesis and the proliferation of human Sertoli cells, as indicated by 5-ethynyl-2'-deoxyuridine (EdU) and Cell Counting Kit-8 (CCK-8) assays. Flow cytometry showed that miR-100-3p mimics reduced the apoptosis of human Sertoli cells, and notably, we predicted and further identified serum/glucocorticoid regulated kinase family member 3 (SGK3) as a direct target of MiR-100-3p. SGK3 silencing increased the proliferation and decreased the apoptosis of human Sertoli cells, while SGK3 siRNA 3 assumed a similar role to miR-100-3p mimics in human Sertoli cells. Collectively, our study indicates that miR-100-3p regulates the fate decisions of human Sertoli cells by binding to SGK3. This study is of great significance, since it provides the novel epigenetic regulator for the proliferation and apoptosis of human Sertoli cells and it may offer a new clue for gene therapy of male infertility.