转基因大豆MON89788芯片式数字PCR定量方法的建立

针对抗虫耐除草剂大豆转基因品系MON89788,从转基因植物基因组DNA的提取、核酸模板的质量和浓度控制、引物探针的筛选、PCR反应过程的建立等方面建立了一套完整的转基因大豆芯片式dPCR定量检测方法。本实验也对该方法的重复性和定量检测限进行考察。10组5%转基因品系大豆MON89788样品定量重复性RSD在1.17%-9.97%之间,均满足国际上转基因定量结果RSD小于25%的要求。用该方法对转基因含量为5%、1%、0.1%的大豆MON89788进行定量检测,其定量结果为5.20%、0.94%和0.11%,RSD分别为6.2%、3.6%和15.2%。该检测方法的定量限达到0.1%,能满足欧盟对转基因定量标识0.9%的要求。将本实验建立的方法用于转基因大豆的定量检测,能为规范我国转基因监管工作的实施提供强有力的技术支撑。     

Screening of significant biomarkers related with prognosis of liver cancer by lncRNA-associated ceRNAs analysis

This study aimed to identify significant biomarkers related to the prognosis of liver cancer using long noncoding RNA (lncRNA)-associated competing endogenous RNAs (ceRNAs) analysis. Differentially expressed mRNA and lncRNAs between liver cancer and paracancerous tissues were screened, and the functions of these mRNAs were predicted by gene ontology and pathway enrichment analyses. A ceRNA network consisting of differentially expressed mRNAs and lncRNAs was constructed. LncRNA FENDRR and lncRNA HAND2-AS1 were hub nodes in the ceRNA network. A risk score assessment model consisting of eight genes (PDE2A, ESR1, FBLN5, ALDH8A1, AKR1D1, EHHADH, ADRA1A, and GNE) associated with prognosis were developed. Multivariate Cox regression suggested that both pathologic_T and risk group could be regarded as independent prognostic factors. Furthermore, a nomogram model consisting of pathologic_T and risk group showed a good prediction ability for predicting the survival rate of liver cancer patients. The nomogram model consisting of pathologic_T and a risk score assessment model could be regarded as an independent factor for predicting prognosis of liver cancer.     

Cucurbitacin I Induces Protective Autophagy in Glioblastoma in Vitro and in Vivo

There is an urgent need for new therapeutic avenues to improve the outcome of patients with glioblastoma multiforme (GBM). Current studies have suggested that cucurbitacin I, a natural selective inhibitor of JAK2/STAT3, has a potent anticancer effect on a variety of cancer cell types. This study showed that autophagy and apoptosis were induced by cucurbitacin I. Exposure of GBM cells to cucurbitacin I resulted in pronounced apoptotic cell death through activating bcl-2 family proteins. Cells treatment with cucurbitacin I up-regulated Beclin 1 and triggered autophagosome formation and accumulation as well as conversion of LC3I to LC3II. Activation of the AMP-activated protein kinase/mammalian target of rapamycin/p70S6K pathway, but not the PI3K/AKT pathway, occurred in autophagy induced by cucurbitacin I, which was accompanied by decreased hypoxia-inducible factor 1α. Stable overexpression of hypoxia-inducible factor 1α induced by FG-4497 prevented cucurbitacin I-induced autophagy and down-regulation of bcl-2. Knockdown of beclin 1 or treatment with the autophagy inhibitor 3-methyladenine also inhibited autophagy induced by cucurbitacin I. A coimmunoprecipitation assay showed that the interaction of Bcl-2 and Beclin 1/hVps34 decreased markedly in cells treated with cucurbitacin I. Furthermore, knockdown of beclin 1 or treatment with the lysosome inhibitor chloroquine sensitized cancer cells to cucurbitacin I-induced apoptosis. Finally, a xenograft model provided additional evidence for the occurrence of cucurbitacin I-induced apoptosis and autophagy in vitro. Our findings provide new insights into the molecular mechanisms underlying cucurbitacin I-mediated GBM cell death and may provide an efficacious therapy for patients harboring GBM.     

Functional role of hedgehog pathway in osteoarthritis

The hedgehog signalling pathway is one of the key regulators of metazoan development, and it plays an important role in the regulation of a variety of developmental and physiological processes. But it is aberrantly activated in many human diseases, including osteoarthritis (OA). In this study, we have reviewed the association of hedgehog signalling pathway in the development and progression of OA and evaluated the efforts to target this pathway for the prevention of OA. Usually in OA, activation of hedgehog induces up-regulation of the expression of hypertrophic markers, including type X collagen, increases production of nitric oxide and prostaglandin E2, several matrix-degrading enzymes including matrix metalloproteinase and a disintegrin and metalloproteinase with thrombospondin motifs in human knee joint cartilage leading to cartilage degeneration, and thus contributes in OA. Targeting hedgehog signalling might be a viable strategy to prevent or treat OA. Chemical inhibitors of hedgehog signalling is promising, but they cause severe side effects. Knockdown of HH gene is not an option for OA treatment in humans because it is not possible to delete HH in larger animals. Efficient knockdown of HH achieved by local delivery of small interfering RNA in future studies utilizing large animal OA models might be a more efficient approach for the prevention of OA. However, it remains a major problem to develop one single scaffold due to the different physiological functions of cartilage and subchondral bones possess. More studies are necessary to identify selective inhibitors for efficiently targeting the hedgehog pathway in clinical conditions.     

JSI-124 Suppresses Invasion and Angiogenesis of Glioblastoma Cells In Vitro

Glioblastoma multiforme (GBM) is one of the utmost malignant tumors. Excessive angiogenesis and invasiveness are the major reasons for their uncontrolled growth and resistance toward conventional strategies resulting in poor prognosis. In this study, we found that low-dose JSI-124 reduced invasiveness and tumorigenicity of GBM cells. JSI-124 effectively inhibited VEGF expression in GBM cells. In a coculture study, JSI-124 completely prevented U87MG cell–mediated capillary formation of HUVECs and the migration of HUVECs when cultured alone or cocultured with U87MG cells. Furthermore, JSI-124 inhibited VEGF-induced cell proliferation, motility, invasion and the formation of capillary-like structures in HUVECs in a dose-dependent manner. JSI-124 suppressed VEGF-induced p-VEGFR2 activity through STAT3 signaling cascade in HUVECs. Immunohistochemistry analysis showed that the expression of CD34, Ki67, p-STAT3 and p-VEGFR2 protein in xenografts was remarkably decreased. Taken together, our findings provide the first evidence that JSI-124 effectively inhibits tumor angiogenesis and invasion, which might be a viable drug in anti-angiogenesis and anti-invasion therapies.     

Targeting Homologous Recombination in Notch-Driven C. elegans Stem Cell and Human Tumors

Mammalian NOTCH1-4 receptors are all associated with human malignancy, although exact roles remain enigmatic. Here we employ glp-1(ar202), a temperature-sensitive gain-of-function C. elegans NOTCH mutant, to delineate NOTCH-driven tumor responses to radiotherapy. At ≤20°C, glp-1(ar202) is wild-type, whereas at 25°C it forms a germline stem cell⁄progenitor cell tumor reminiscent of human cancer. We identify a NOTCH tumor phenotype in which all tumor cells traffic rapidly to G2⁄M post-irradiation, attempt to repair DNA strand breaks exclusively via homology-driven repair, and when this fails die by mitotic death. Homology-driven repair inactivation is dramatically radiosensitizing. We show that these concepts translate directly to human cancer models.