Design and synthesis of novel Gefitinib analogues with improved anti-tumor activity

There is an urgent need to design and develop new and more potent EGFR inhibitors with improved anti-tumor activity. Here we describe the design and synthesis of two series of 4-benzothienyl amino quinazolines as new analogues of the EGFR inhibitor Gefitinib. The anti-tumor activity of these novel Gefitinib analogues in 6 human cancer cell lines was examined. Compared with the parental Gefitinib, most of the new compounds show a markedly increased cytotoxicity to cancer cells. Furthermore, several of the series B compounds that side chains at position 7 contain either a methyl or ethyl group are potent pan-RTK inhibitors. Two representative compounds in this class, 15 and 17, have an enhanced capability to inhibit cancer cell growth and induce apoptosis in vitro and inhibit tumor formation in vivo in human cancer cells with high HER-2, as compared with the parental Gefitinib. Thus they may be promising lead compounds to be developed as an alternative for current Gefitinib therapy or for Gefitinb-resistant patients, potentially via simultaneously blocking multiple RTK signaling pathways.     

γ-辐射与常规方法灭活产单核细胞李斯特菌对小鼠免疫原性的比较

【目的】以产单核细胞李斯特菌(Listeria monocytogenes, LM)为模式菌, 比较γ-辐射及常规的热灭活、甲醛灭活制备的灭活李斯特菌对小鼠的免疫原性。【方法】以γ-辐射、热灭活和甲醛灭活法分别制备灭活的LM;腹腔注射BALB/c小鼠,ELISA检测各组灭活菌产生的抗体水平;观察野生型LM攻击后各组的保护效果,动态监测体内带菌情况;流式细胞仪分选免疫小鼠T细胞,以T细胞转移实验评价辐射灭活的LM产生的免疫应答。【结果】 辐射灭活组、热灭活组和甲醛灭活组产生的抗体水平分别为：1:1280, 1:640, 1:160;野生型细菌攻击后这3种灭活菌产生的保护率分别为：100%、35%、30%,其中免疫辐射灭活菌的小鼠能够较快清除攻击的细菌;辐射灭活李斯特菌能够激发产生T细胞保护性免疫应答。【结论】较之传统的灭活方法,利用γ-辐射制备的灭活LM免疫小鼠后能够产生较好的保护效果。     

HN1L promotes migration and invasion of breast cancer by up-regulating the expression of HMGB1

Recent reports showed that haematological and neurological expressed 1-like (HN1L) gene participated in tumorigenesis and tumour invasion. However, the expression and role of HN1L in breast cancer remain to be investigated. Here, bioinformatics, western blot and immunohistochemistry were used to detect the expression of HN1L in breast cancer. Wound healing, transwell assay, immunofluorescence assay and mass spectrum were used to explore the role and mechanism of HN1L on the migration and invasion of breast cancer, which was confirmed in vivo using a nude mice model. Results showed that HN1L was significantly over-expressed in breast cancer tissues, which was positively correlated with M metastasis of breast cancer patients. Silencing HN1L significantly inhibited the invasion and metastasis of breast cancer cells in vitro and lung metastasis in nude mice metastasis model of breast cancer. Mechanistically, HN1L interacted with HSPA9 and affected the expression of HMGB1, playing a key role in promoting the invasion and metastasis of breast cancer cell. These results suggested that HN1L was an appealing drug target for breast cancer.     

Biocathode microbial fuel cell for efficient electricity recovery from dairy manure

Microbial fuel cells (MFCs) represent a new biological method for generating electricity directly from biodegradable compounds. Efficiency of MFCs using manure as substrate is generally low. This study proposed a new design by incorporating biocathodes into a three-chamber MFC, which yielded maximum power densities much higher than those reported in literature. The new design placed cylindrical anode chamber for easy stirring and two symmetrical cathodic chambers with reduced anode-cathode distance. The biocathodes were applied to reduce charge transfer resistance. Additionally, biocathode microbial community was cultured to enrich favorable microorganisms. With external loading of 100 Ω, the power densities for new biocathode MFC using 2, 4, 6, 8 and 10% total solids diary manure reached 7.85±1.0 W m(-3), 7.84±1.20 W m(-3), 8.15±0.20 W m(-3), 7.60±0.97 W m(-3) and 5.63±0.97 W m(-3), respectively. The pH drop as a result of manure hydrolysis limited the power output. To provide detailed information of the microbial community in the biocathode MFC, the 454-pyrosequencing technique was adopted. The Firmicutes, γ-, β-, α- and δ-Proteobacteria, Bacteroidetes and Actinobacteria were the major groups on the anode, while γ-, β-, and α-Proteobacteria, Bacteroidetes and Actinobacteria were the predominant groups on the cathode.     

G protein coupled receptor transactivation: extending the paradigm to include serine/threonine kinase receptors

The current paradigm of G protein coupled receptor signaling involves a classical pathway being the activation of phospholipase C and the generation of 1,4,5-inositol trisphosphate, signaling through β-arrestin scaffold molecules and the transactivation of tyrosine kinase growth factor receptors. Transactivation greatly expands the range of signaling pathways and responses attributable to the receptor. Recently it has been revealed that G protein coupled receptor agonists can also transactivate the serine/threonine kinase cell surface receptor for transforming growth factor-β (Alk5). This leads to the generation of carboxyl terminal phosphorylated Smad2 which is the immediate downstream product of the activated Alk5. Thus, the current paradigm of G protein coupled signaling can be expanded to include the transactivation of the serine kinase receptor Alk5. These insights expand the possibilities for outcomes of therapeutically targeting GPCRs where more substantive and prolonged actions such as the synthesis of extracellular matrix may be affected.     

Association Between Chronic Exposure to Tobacco Smoke and Accumulation of Toxic Metals in Hair Among Pregnant Women

Tobacco smoke contains various toxic heavy metals that individuals are exposed to when they smoke. Despite the presence of heavy metals in tobacco smoke, the relationship between smoking and the accumulation of toxic metals in pregnant women after long-term exposure remains under discussion. We examined the association between long-term exposure to tobacco smoke and the accumulation of toxic metals in the hair of female participants. Our study recruited 252 women from the Shanxi and Hebei provinces of Northern China; these participants were self-reported non-active smokers, and had previously delivered healthy babies without birth defects. Scalp hair was collected and analyzed for nicotine and cotinine and five potentially toxic metals (specifically, silver, chromium, cadmium, mercury, and lead). Our results showed significant positive correlations between cotinine and four metals, including silver (r?=?0.369, p?<?0.001), cadmium (r?=?0.185, p?<?0.01), mercury (r?=?0.161, p?<?0.05), and lead (r?=?0.243, p?<?0.001). Significant positive correlations were also found between nicotine and three metals—specifically silver (r?=?0.331, p?<?0.001), cadmium (r?=?0.176, p?<?0.01), and lead (r?=?0.316, p?<?0.001). A logistic regression model showed significant associations between cotinine and potentially toxic metals including mercury, silver, and lead (with or without adjusting for potential confounders). We thus conclude that long-term passive smoking could potentially increase the exposure level of toxic metals including lead, silver, and mercury in our study, which are especially harmful for pregnant women and their unborn fetus.     

Developmentally regulated alternative splicing of densin modulates protein-protein interaction and subcellular localization

Densin is a member of the leucine-rich repeat (LRR) and PDZ domain (LAP) protein family that binds several signaling molecules via its C-terminal domains, including calcium/calmodulin-dependent protein kinase II (CaMKII). In this study, we identify several novel mRNA splice variants of densin that are differentially expressed during development. The novel variants share the LRR domain but are either prematurely truncated or contain internal deletions relative to mature variants of the protein (180 kDa), thus removing key protein–protein interaction domains. For example, CaMKIIα coimmunoprecipitates with densin splice variants containing an intact C-terminal domain from lysates of transfected HEK293 cells, but not with variants that only contain N-terminal domains. Immunoblot analyses using antibodies to peptide epitopes in the N- and C- terminal domains of densin are consistent with developmental regulation of splice variant expression in brain. Moreover, putative splice variants display different subcellular fractionation patterns in brain extracts. Expression of green fluorescent protein (GFP)-fused densin splice variants in HEK293 cells shows that the LRR domain can target densin to a plasma membrane-associated compartment, but that the splice variants are differentially localized and have potentially distinct effects on cell morphology. In combination, these data show that densin splice variants have distinct functional characteristics suggesting multiple roles during neuronal development.     

Diversity and Abundance of Nitrate Assimilation Genes in the Northern South China Sea

Marine heterotrophic microorganisms that assimilate nitrate play an important role in nitrogen and carbon cycling in the water column. The nasA gene, encoding the nitrate assimilation enzyme, was selected as a functional marker to examine the nitrate assimilation community in the South China Sea (SCS). PCR amplification, restriction fragment length polymorphism (RFLP) screening, and phylogenetic analysis of nasA gene sequences were performed to characterize in situ nitrate assimilatory bacteria. Furthermore, the effects of nutrients and other environmental factors on the genetic heterogeneity of nasA fragments from the SCS were evaluated at the surface in three stations, and at two other depths in one of these stations. The diversity indices and rarefaction curves indicated that the nasA gene was more diverse in offshore waters than in the Pearl River estuary. The phylotype rank abundance curve showed an abundant and unique RFLP pattern in all five libraries, indicating that a high diversity but low abundance of nasA existed in the study areas. Phylogenetic analysis of environmental nasA gene sequences further revealed that the nasA gene fragments came from several common aquatic microbial groups, including the Proteobacteria, Cytophaga–Flavobacteria (CF), and Cyanobacteria. In addition to the direct PCR/sequence analysis of environmental samples, we also cultured a number of nitrate assimilatory bacteria isolated from the field. Comparison of nasA genes from these isolates and from the field samples indicated the existence of horizontal nasA gene transfer. Application of real-time quantitative PCR to these nasA genes revealed a great variation in their abundance at different investigation sites and water depths.