Metagenomic analysis of the dynamical conversion of photosynthetic bacterial communities in different crop fields over different growth periods.

Photosynthetic bacteria are beneficial to plants, but knowledge of photosynthetic bacterial community dynamics in field crops during different growth stages is scarce. The factors controlling the changes in the photosynthetic bacterial community during plant growth require further investigation. In this study, 35 microbial community samples were collected from the seedling, flowering, and mature stages of tomato, cucumber, and soybean plants. 35 microbial community samples were assessed using Illumina sequencing of the photosynthetic reaction center subunit M (pufM) gene. The results revealed significant alpha diversity and community structure differences among the three crops at the different growth stages. Proteobacteria was the dominant bacterial phylum, and Methylobacterium, Roseateles, and Thiorhodococcus were the dominant genera at all growth stages. PCoA revealed clear differences in the structure of the microbial populations isolated from leaf samples collected from different crops at different growth stages. In addition, a dissimilarity test revealed significant differences in the photosynthetic bacterial community among crops and growth stages (P<0.05). The photosynthetic bacterial communities changed during crop growth. OTUs assigned to Methylobacterium were present in varying abundances among different sample types, which we speculated was related to the function of different Methylobacterium species in promoting plant growth development and enhancing plant photosynthetic efficiency. In conclusion, the dynamics observed in this study provide new research ideas for the detailed assessments of the relationship between photosynthetic bacteria and different growth stages of plants.

ISL2 modulates angiogenesis through transcriptional regulation of ANGPT2 to promote cell proliferation and malignant transformation in oligodendroglioma.

Oligodendroglioma is an important type of lower-grade glioma (LGG), which is a slowly progressing brain tumor. Many LGGs eventually transform into a more aggressive or malignant type. Enhanced angiogenesis is a characteristic of malignantly transformed oligodendroglioma (m-oligodendroglioma). However, the pathogenesis and signaling pathways associated with angiogenesis and proliferation in m-oligodendroglioma are not well understood. In this study, we identified that Insulin Gene Enhancer Protein (ISL2) and its angiogenic capacity were inversely related to survival according to LGG patient data from an online database, and this was further confirmed with pathological LGG patient samples, including malignantly transformed samples, by detecting the expression of ISL2, the angiogenic markers vascular endothelial growth factor (VEGFA) and CD31 and the proliferation marker Ki-67. We then established novel oligodendroglioma patient tumor-derived orthotopic xenograft mouse models and cell lines to verify the role of ISL2 in regulating angiogenesis to promote oligodendroglioma growth and malignant transformation. Furthermore, ISL2 regulated ANGPT2 transcription by binding to the ANGPT2 promoter. Then, ANGPT2, a downstream gene, activated angiogenesis through VEGFA to promote oligodendroglioma malignant transformation. Finally, combining AAV-ISL2-shRNA with temozolomide suppressed oligodendroglioma progression more effectively than either monotherapy in vivo and in vitro. Thus, hypoxia-induced ISL2 regulated ANGPT2, which subsequently induced angiogenesis to promote oligodendroglioma growth and malignant transformation. Malignancy was accompanied by worsened hypoxia inside the tumor mass, creating a positive feedback loop. In conclusion, this study suggests that ISL2 is a biomarker for oligodendroglioma progression and that anti-ISL2 therapy may offer a potential clinical strategy for treating m-oligodendroglioma.

Actein inhibits glioma growth via a mitochondria-mediated pathway.

Previous studies indicate that the triterpene glycoside Actein from the herb black cohosh inhibits growth of human breast cancer cells. This study sought to investigate the effects of Actein on glioma cell growth and explore the potential mechanisms. Our results showed that administration of Actein significantly inhibited glioma cell viability in a dose- and time-dependent manner. Actein also increasingly inhibited the colony formation processes in glioma U87 cells and U251 cells. Administration of Actein also induced mitochondria-related apoptosis by increasing expression of pro-apoptotic factors Bax, cleaved caspase-3, cleaved caspase-9 and cleaved poly (ADP-ribose) polymerase 1 (PARP1) as well as decreasing anti-apoptotic Bcl-2 expression in U87 cells and U251 cells. In a xenograft model of glioma, Actein suppressed tumor growth and consistently induced cell apoptosis with the same mechanisms observed in vitro. In all, this study is the first report to address the growth inhibitory effects of Actein on glioma growth and propose that mitochondria-mediated apoptosis pathway may underlie the biological activities of Actein in glioma. Our study suggests that administration of Actein may serve as a potent therapeutic strategy for treatment of glioma.

Relationship between tumour location and preoperative seizure incidence in patients with gliomas: a systematic review and meta-analysis.

AIM: The aim of this meta-analysis was to assess the relationship between tumour location and preoperative seizure incidence in patients with gliomas. METHODS: Systematic computerised searches of PubMed and the Web of Knowledge were performed. The meta-analysis of pooled odds ratio (OR) and 95% confidence interval (CI) for preoperative seizure risk, stratified by tumour location, were calculated. RESULTS: Eleven studies with 2,047 patients were included for meta-analysis. For gliomas with or without frontal lobe involvement, the preoperative seizure incidence ranged from 31.7% (19/60) to 85.7% (156/182) and 19.7% (12/61) to 85.7% (12/14), respectively; the pooled OR was 1.560 (95% CI: 1.266-1.923; Z: 4.17; p=0.000). For gliomas with or without temporal lobe involvement, seizure incidence was 22.6% (7/31) to 91.7% (11/12) and 26.7% (24/90) to 78.7% (174/221), respectively; the pooled OR was 1.070 (95% CI: 0.794-1.443; Z: 0.45; p=0.656). For gliomas with or without parietal lobe involvement, seizure incidence was 18.1% (3/16) to 100.0% (3/3) and 26.7% (28/105) to 80.4% (226/281), respectively; the pooled OR was 0.770 (95% CI: 0.570-1.040; Z: 1.71; p=0.088). For gliomas with or without occipital lobe involvement, seizure incidence was 0.0% (0/2) to 100.0% (2/2) and 26.8% (30/112) to 75.7% (56/74), respectively; the pooled OR was 0.336 (95% CI: 0.164-0.686; Z: 2.99; p=0.003). For gliomas with or without insula lobe involvement, seizure incidence was 34.8% (8/23) to 72.0% (77/107) and 34.3% (60/175) to 81.3% (247/304), respectively; the pooled OR was 1.058 (95% CI: 0.765-1.463; Z: 0.34; p=0.732). No significant publication bias was found. CONCLUSION: Our meta-analysis indicates that frontal lobe gliomas are related to a higher preoperative seizure incidence, while occipital lobe gliomas are related to a lower incidence.