The genome sequence, genetic characterization and nblA gene function of Microcystis aeruginosa myovirus isolated from Lake Dianchi in China (MaMV-DC) have been analysed. The genome DNA is 169 223 bp long, with 170 predicted protein-coding genes (001L-170L) and a tRNA gene. About one-sixth of these genes have homologues in the host cyanobacteria M. aeruginosa. The genome carries a gene homologous to host nblA, which encodes a protein involved in the degradation of cyanobacterial phycobilisome. Its expression during MaMV-DC infection was confirmed by reverse transcriptase PCR and Western blot detection and abundant expression was companied by the significant decline of phycocyanin content and massive release of progeny MaMV-DC. In addition, expressing MaMV-DC nblA reduced the phycocyanin peak and the phycocyanin to chlorophyll ratio in model cyanobacteria. These results confirm that horizontal gene transfer events have occurred between cyanobacterial host and cyanomyovirus and suggest that MaMV-DC carrying host-derived genes (such as 005L, that codes for NblA) is responsible for more efficient expression of cyanophage genes and release of progeny cyanophage. This study provides novel insight into the horizontal gene transfer in cyanophage and the interactions between cyanophage and their host.

The MaMV-DC cyanophage, which infects the bloom-forming cyanobacterium Microcystis aeruginosa, was isolated from Lake Dianchi, Kunming, China. Twenty-one cyanobacterial strains were used to detect the host range of MaMV-DC. Microcystic aeruginosa FACHB-524 and plaque purification were used to isolate individual cyanophages, and culturing MaMV-DC with cyanobacteria allowed us to prepare purified cyanophages for further analysis. Electron microscopy demonstrated that the negatively stained viral particles are tadpole-shaped with an icosahedral head approximately 70 nm in diameter and a contractile tail approximately 160 nm in length. Using one-step growth experiments, the latent period and burst size of MaMV-DC were estimated to be 24-48 hours and approximately 80 infectious units per cell, respectively. Restriction endonuclease digestion and agarose gel electrophoresis were performed using purified MaMV-DC genomic DNA, and the genome size was estimated to be approximately 160 kb. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis revealed four major structural proteins. These results support the growing interest in using freshwater cyanophages to control bloom-forming cyanobacterium.

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Metformin, as the first-line oral drug for type 2 diabetes, has proven benefits against aging, cancer and cardiovascular diseases. But the influence of metformin to the immune response and its molecular mechanisms remain obscure. Metformin increases resistance to not only the Gramnegative pathogens Pseudomonas aeruginosa and Salmonella enterica but also the Gram-positive pathogens Enterococcus faecalis and Staphylococcus aureus. Meanwhile, metformin protects the animals from the infection by enhancing the tolerance to the pathogen infection rather than by reducing the bacterial burden. Through the screening of classical immune pathways in C. elegans, we find metformin enhances innate immunity through p38 MAPK pathway. Furthermore, activated p38/PMK-1 by metformin acts on the intestine for innate immune response. In addition, metformin-treated mice have increased resistance to P. aeruginosa PA14 infection and significantly increased the levels of active PMK-1. Therefore, promoted p38/PMK-1-mediated innate immunity by metformin is conserved from worms to mammals. Our work provides a conserved mechanism by which metformin enhances immune response and boosts its therapeutic application in the treatment of pathogen infection.

Background Hepatocellular carcinoma (HCC) is the most aggressive and frequently diagnosed malignancy of the liver. Despite aggressive therapy, life expectancy of many patients in these cases is extended by only a few months. Hepatocellular carcinoma (HCC) has a particularly poor prognosis and would greatly benefit from more effective therapies. Methods The CCK-8 assay and colony formation assays were used to test the cell proliferation and viability. The effects of combination Biochanin A and SB590885 on apoptosis and cell cycle arrest of HCC cells were analysed by flow cytometry. The expression of ERK MAPK and PI3K/AKT/mTOR signalling as well as apoptosis and cell cycle-related proteins in HCC cells were tested by western blotting. The HCC cell xenograft model was established to test the tumor proliferation. Serum and plasma were tested for liver and kidney safety markers (ALP, ALT, AST, total bilirubin, creatinine, urea nitrogen) by using SpectraMax i3X. Results The combination of natural product Biochanin A with the BRAF inhibitor SB590885 synergistically suppressed proliferation, and promoted cell cycle arrest and apoptosis in vitro. Furthermore, we demonstrated that the combination of Biochanin A and SB590885 led to increased impairment of proliferation and HCC tumour inhibition through disrupting of the ERK MAPK and the PI3K/AKT pathways in vitro. The volumes tumors and the weights of tumours were significantly reduced by the combination treatment compared to the control or single treatments in vivo. In addition, we found that there was no significant hepatorenal toxicity with the drug combination, as indicated by the hepatorenal toxicity test. Conclusion The results identify an effective combination therapy for the most aggressive form of HCC and provide the possibility of therapeutic improvement for patients with advanced HCC.

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Two new 19-hydroxy bufadienolides, named bufohydrolide A (1) and bufohydrolide B (2), and four known analogs (3-6) were isolated from the aqueous extracts of the skins of Bufo melanosticus. Their structures were established by spectral data analyses, such as UV, IR, 1D/2D NMR and mass spectra. Compounds 1-6 were evaluated for their cytotoxic activity against SMMC-7721, HT-29 and A549 cells. Noteworthily, all six isolates exhibited various levels of anti-proliferative activities with IC 50 values ranging from 0.02 ± 0.0002 to 25±0.5 μM.

Abstract. In this study, aioxidant and anticancer activities of the extracts were evaluated from various habitats of Selaginella doederleinii. The evaluation on antioxidative capacity revealed that the extracts were the highest from Guizhou province using DPPH radical scavenging, ABTS radical scavenging, ferric reducing and FRAP methods, while those of the extracts from Sichuan province were the lowest from different habitats. The evaluation on antitumous effect showed that the extracts from Guizhou province were the highest against A549 cell line and 7721 cell line, while those of the extracts from Sichuan province were the lowest in different habitats. Results obtained revealed that the extracts of S. doederleinii were found to be potentially as a readily valuable bioactive source of natural products. Ethyl acetate extraction of S. doederleinii exhibited as the most potent fraction will be further in-depth study.