Identification of onco-miRNAs in hepatocellular carcinoma and analysis of their regulatory network / 南方医科大学学报

OBJECTIVE@#To construct the regulatory network of survival-related onco-miRNAs and their target genes in hepatocellular carcinoma (HCC) and verify the interactions between the key miRNAs and their targets.@*METHODS@#We screened survival-related miRNAs in HCC in OncomiR and Oncolnc databases, predicted their target genes using miRNet, and conducted survival and expression analysis using GEPIA2 and Ualcan, respectively. The miRNA-target gene co-expression analysis was performed and the miRNA-target network was constructed. Enrichment analysis was performed in Enrichr and protein-protein interaction analysis in STRING database. We tested the effects of transfection with the mimic or inhibitor of hsa-miR-1226-3p or hsa-miR-221-5p on proliferation of HepG2 cells using CCK8 assay and examined the changes in the expressions of the target genes using RT-qPCR. The effect of transfection with hsa-miR-221-5p mimic or inhibitor on protein expressions of the target genes was examined using Western blotting in. A dual luciferase reporter assay was used to test the interaction between hsa-miR-221-5p and its potential target gene GCDH. We further examined the effect of transfection with hsa-miR-221-5p mimic and pEGFP N1-GCDH, alone or in combination, on proliferation, migration and invasion of HepG2 cells.@*RESULTS@#We identified 223 survival-related miRNAs in HCC from OncomiR and 146 miRNAs from Oncolnc with an intersection of 131 miRNAs, and 48 miRNAs were identified as onco-miRNAs in HCC after survival and expression analysis. Twenty-seven eligible target genes were identified after miRNA-mRNA co-expression analysis. The constructed miRNA-target gene network consisted of 25 miRNAs and 27 target genes. The most enriched term was fatty acid metabolism for the target genes. In HepG2 cells, transfection with the mimic or inhibitor of hsa-miR-1226-3p or hsa-miR-221-5p caused significant changes of the mRNA and protein levels of their respective target genes (P < 0.05). The results of dual luciferase reporter assay confirmed the targeting relationship between hsa-miR-221-5p and GCDH gene (P < 0.05). Transfection with hsa-miR-221-5p mimic significantly suppressed the proliferation, migration and invasion of HepG2 cells, but this effect was obviously relieved by co-transformation with pEGFP N1-GCDH (P < 0.05).@*CONCLUSION@#Fatty acid metabolism might be one of the most crucial pathways that mediate the effect of the oncomiRNAs in HCC, and the hsa-miR-221-5p/GCDH axis is an important molecular mechanism for HCC progression.

Identifying and Validating a Novel miRNA-mRNA Regulatory Network Associated with Prognosis in Lung Adenocarcinoma / 中国医学科学杂志(英文版)

Objective Many studies have revealed the crucial roles of miRNA in multiple human cancers, including lung adenocarcinoma (LUAD). In this study, we sought to explore new miRNA-mRNA pairs that are associated with LUAD prognosis. Methods A novel miRNA-mRNA regulatory network associated with prognosis in LUAD was identified and validated using the bioinformatic tools including OncomiR database, StarBase, miRnet, GEPIA2, UALCAN. Results Twenty key miRNAs were compiled after the analysis of the expression and prognostic value in OncomiR and StarBase. Targeted mRNAs of these key miRNAs were predicted in miRnet, and the resulting mRNAs were also analyzed for their prognostic values and expression patterns in GEPIA2 and UALCAN, respectively. Further expression correlation analysis was performed in StarBase. Subsequently, a new miRNA-mRNA network was built, of which each RNA pair showed negative expression correlation, opposite expression pattern, and prognostic value. Protein-protein interaction network was under construction for the mRNAs, and 19 hub genes were determined. Enrichment analysis showed that "Cell Cycle, Mitotic" was the most significantly enriched term. Then, a miRNA-hub gene sub-network was built. We selected and validated the regulatory relationship of some miRNA-hub pairs, including hsa-miR-1976/RFC2, hsa-let-7c-5p/RFC2, hsa-let-7c-5p/ESPL1, hsa-let-7c-5p/CDC25A, and hsa-miR-101-3p/KIF2C. Moreover, over-expression of hsa-miR-1976 and hsa-let-7c-5p resulted in significant cell cycle arrest. Conclusions Our results determined new prognosis-associated miRNA-mRNA pairs and might shed further light on the mechanism via which miRNA-mRNA network influences prognosis in LUAD.

Roles of integrin αvβ3 in SDF-1/CXCR4-induced choroidal neovascularization / 眼科新进展

Objective To explore the role of integrin αvβ3 in the promotion of the development of choroidal neovascularization (CNV) by SDF-1/CXCR4.Methods This study was divided into two parts in vitro and in vivo.As for the in vivo study,a CNV model was induced by laser on C57BL/6J mice,and then assigned into 4 groups:mice with solely CNV modeling as control group,with intravitreal injection of SDF-1 after immediate CNV modeling as SDF-1 group,with intravitreal injection of SDF-1 + CXCR4 inhibitor (AMD3100) after CNV modeling as SDF-1 + AMD3100 group,and mice with intravitreal injection of SDF-1 + αvβ3 inhibitor (SB273005) after modeling as SDF-1 + SB273005 group.CXCR4 and αvβ3 expression levels in laser-induced eyes were quantified by qRT-PCR at time points of day 1,3,5,7,10 and 14 after modeling,and immunofluorescence staining was applied to detect αvβ3 expression in regional CNV and its endothelial cells in the four groups.Finally,OCT was used to observe the height of retinal pigment epithelial (RPE) layers in CNV after treatment in the four groups.Moreover,in the experiment in vitro,Western blot was used to measure the expression of CXCR4 protein of RF/6A cells in normal control group,Si-CXCR4 knockdown group and Si-NC knockdown model group.Meanwhile,the expression of integrin subunit β3 protein was determined in the normal control group,SDF-1 group,SDF-1 + AMD3100group,SDF-1 + Si-NC group and SDF-1 + Si-CXCR4 group.Transwell assay was conducted to detect the migration ability of RF/6A cells in the normal control group,SDF-1group,SDF-1 +AMD3100 group,SDF-1 + SB273005 group.Results On the one hand,the study in vivo,qRT-PCR showed that the expression of CXCR4 and integrin subunit β3 mRNA was up-regulated at first,and then down-regulated with time passed after CNV induction,with the highest expression level of CXCR4 mRNA (4.263 ± 0.464) on day 3,and the peak expression of β3 mRNA (3.678 ±0.364) on day 7 after CNV modeling.The results of immunofluorescence staining showed that the β3 fluorescence intensity of SDF-1 group was significantly enhanced,and the ratio of β3/CD31 was also significantly increased,which both were significantly higher than those of the control group (P ＜ 0.01).However,the β3 fluorescence intensity and β3/CD31 ratio of SDF-1 +AMD3100 group and SDF-1 + SB273005 group were significantly weakened and decreased,respectively (P ＜0.05).OCT showed that the elevation level of RPE layer inSDF-1 group was significantly higher than that in the control group [(135.503 ± 10.301) μm vs.(94.443 ± 12.156) μm](P＜0.05).The height of RPE uplift in SDF-1 + AMD3100 group [(95.283 ±20.062) μm] and SDF-1 + SB273005 group [(99.807 ± 10.403) μm] was significantly decreased (P ＜ 0.05).On the other hand,in experiment in vitro,Western blot showed that the expression levels of integrin β3 in SDF-1 group and SDF-1 + Si-NC group were significantly higher than those in the control group [(1.301 ± 0.043) and (1.273 ± 0.077) vs.(0.244 ± 0.069)] (P ＜ 0.01).The levels of integrin subunit β3 protein in SDF-1 + si-CXCR4 group (0.322 ± 0.042) and SDF-1 + AMD3100 group (0.336 ± 0.077) were significantly down-regulated (P ＜ 0.01).Transwell assay showed that the amount of migrating cells in SDF-1 group increased,which was significantly higher than that of the control group (P ＜ 0.01),while the number of migrating cells in SDF-1 +AMD3100 group and SDF-1 + SB273005 group was significantly decreased.Conclusion Integrin αvβ3 can promote the development of CNV by mediating SDF-1/CXCR4 signaling in endothelial cells.

Promotion effect and mechanism of Caspase - 1 on microglia in retinal neovascularization in oxygen -induced retinopathy / 国际眼科杂志(Guoji Yanke Zazhi)

·AIM: To investigate the effect and mechanism of Caspase- 1 on microglia in oxygen - induced retinal neovascularization in mice. ·METHODS: Twelve 7-day-old (P7) C57BL/6J mice were randomly divided into normal group,OIR group and OIR+VX-765 group. OIR models were established in OIR group and OIR+VX-765 group. Caspase-1 inhibitor VX-765(4mg/kg, dissolved in 0.4% polyethylene glycol) or 0. 4% polyethylene glycol, were intraperitoneally injected from P12 to P16 into the mice of OIR+VX-765 and OIR groups,respectively. Whole retinal flatmounts of P17 mice were prepared, and Lectin staining was performed to calculate the ratio of avascular and neovascular area to retina area. The frozen sections of the posterior ocular segment were prepared,and the distribution of Caspase-1 and activated microglial cells were detected by immunofluorescence technique. Cultured BV-2 cells were divided into control group, hypoxia group and inhibitor group. The cells of inhibitor and hypoxia groups were pre-treated with VX-765 or 0.4% polyethylene glycol for 3h, and then hypoxic incubated for 24h. The expression levels of Caspase-1, p20 (active form of Caspase-1), IL-1β and VEGF were detected by Western blotting. The angiogenesis and migration capacity of cultured RF/6A cells were assessed by endothelial cell tube formation assay and migration assay,after they were incubated with supernatant of those different BV-2 groups. ·RESULTS:The distribution and morphology of retinal blood vessels were normal in P17 mice of the normal group,and avascular and new blood vessel cluster were found in the mice of OIR group and OIR+VX-765 group. The ratio of avascular area was 12.23% ±1.02% and that of the new blood vessel area was 2.16% ±0.52% in the OIR+VX- 765 group, which decreased in comparison with 16.58% ± 1.14% and 4.00% ± 0.41% of the OIR group(P<0.01 ). Caspase - 1 was rarely detected by immunofluorescence staining in the normal retina of the mice, whereas it was mainly co-located with activated microglial cells in the ganglion cell layer and the inner plexiform layer in the mice of OIR group. The expression of Caspase-1, p20, IL-1β and VEGF increased in BV-2 cells of the hypoxia group, which were down-regulated by VX-765(P<0.05), except Caspase-1. The tube length was 271±12,and the number of migrated cells was 347±34 in RF/6A cells cultured with supernatant of BV-2 cells in the hypoxia group, which significantly decreased to 171 ± 22 and 212±27 with inhibitor of Caspase-1 (P<0.05). · CONCLUSION: Caspase - 1 promotes retinal neovascularization in the mice with OIR, probably by activating the downstream inflammatory factor IL-1β in microglial cells and accelerating the release of VEGF.