Edelfosine-induced metabolic changes in cancer cells that precede the overproduction of reactive oxygen species and apoptosis

Background  

Metabolic flux profiling based on the analysis of distribution of stable isotope tracer in metabolites is an important method widely used in cancer research to understand the regulation of cell metabolism and elaborate new therapeutic strategies. Recently, we developed software Isodyn, which extends the methodology of kinetic modeling to the analysis of isotopic isomer distribution for the evaluation of cellular metabolic flux profile under relevant conditions. This tool can be applied to reveal the metabolic effect of proapoptotic drug edelfosine in leukemia Jurkat cell line, uncovering the mechanisms of induction of apoptosis in cancer cells.     

Heterologous expression and characterization of a novel halotolerant,thermostable, and alkali-stable GH6 endoglucanase from <Emphasis Type="Italic">Thermobifida halotolerans</Emphasis>

A novel endoglucanase gene was cloned from Thermobifida halotolerans YIM 90462^T, designated as thcel6A for being a member of glycoside hydrolase family 6. The gene was 1332 bp long and encoded a 443-amino-acid protein with a molecular mass of 45.9 kDa. The purified recombinant endoglucanase had optimal activity at 55 °C and pH 8.5. Thcel6A showed high hydrolytic activities at 25–55 °C and retained 58 % of initial activity after incubation at 90 °C for 1 h. It retained more than 80 % of activity after incubation for 12 h at pH values from 4 to 12. Thcel6A displayed higher hydrolytic activities in 5–15 % NaCl (w/v) than at 0 % NaCl. Activity increased 2.5-fold after incubation with 20 % (w/v) NaCl at 37 °C for 10 min. These properties suggest that this novel endoglucanase has potential for specific industrial application.     

Eukaryotic microbial communities in hypersaline soils and sediments from the alkaline hypersaline Huama Lake as revealed by 454 pyrosequencing

In hypersaline ecosystems, microbial assemblages are structurally distinctive and play important roles in many microbiological and ecological processes. Here, eukaryotic microorganisms in hypersaline samples were investigated by 454 pyrosequencing of internal transcribed spacer (ITS) gene libraries. In total, 4,645, 1,677, and 5,912 reads were obtained from ITS libraries of waterlogged samples, salt crusts, and saline loess from the alkaline Huama Lake in Shaanxi, China. Analyses of pyrosequencing data revealed that the dominant genera were Dunaliella, Alternaria and Chlamydomonas, which dominated the microbial assemblages in the waterlogged sediments, the salt crusts and the saline loess from the lake banks, respectively. The various infrequent species were not commonly shared by the three types of samples, demonstrating that the eukaryotic microbial compositions of the different environments were distinct. However, the micro-eukaryotic assemblages associated with similar environmental conditions shared some components and were phylogenetically related. The eukaryotic microbial community composition was correlated with the pH value of the site (p = 0.001; r² = 0.99), but not with the concentration of total nitrogen or the inorganic ions investigated in this study. The results of this study demonstrated that the hypersaline ecosystems hosted surprisingly diverse eukaryotic microbial community.     

Paenibacillus nicotianae sp. nov., isolated from a tobacco sample

A Gram-stain positive, facultative anaerobic endospore-forming bacterium, designated strain YIM h-19^T, was isolated from a tobacco sample. Cells were observed to be motile rods by means of peritrichous flagella and colonies were observed to be convex, yellow, circular and showed catalase-positive and oxidase-negative reactions. Strain YIM h-19^T was able to grow at 4–45 °C, pH 6.0–8.0 and 0–3 % NaCl (w/v). The predominant respiratory quinone was identified as MK-7. Major fatty acids were identified as anteiso-C_15:0, anteiso-C_17:0 and C_16:0. The polar lipids were found to be phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol and two unidentified polar lipids. The genomic DNA G+C content was determined to be 54 mol%. 16S rRNA gene sequence analysis showed the strain YIM h-19^T was most closely related to Paenibacillus hordei RH-N24^T and Paenibacillus hunanensis FeL05^T with similarities of 98.30 and 94.64 % respectively. However, DNA–DNA hybridization data indicated that the isolate represented a novel genomic species with the genus Paenibacillus. All data from genotypic and phenotypic analyses support the conclusion that strain YIM h-19^T represents a novel species of the genus Paenibacillus, for which the name Paenibacillus nicotianae sp. nov. is proposed. The type strain is YIM h-19^T (=CGMCC1.12819^T = NRRL B-59112^T).     

Gordonia jinhuaensis sp. nov., a novel actinobacterium,isolated from a VBNC (viable but non-culturable) state in pharmaceutical wastewater

A Gram-stain positive, aerobic, non-motile and rod-shaped actinobacterial strain, designated as ZYR 51^T, was isolated from pharmaceutical wastewater in Jinhua city, Zhejiang province, Eastern China. Isolation was aided by using a resuscitation-promoting factor, suggesting the strain was recovered from a viable but non-culturable state. Strain ZYR 51^T was characterized by a polyphasic taxonomic approach. Growth was found to occur at 10–45 °C, pH 6.0–10.0 and 0–9 % NaCl (w/v). Based on the 16S rRNA gene sequence, phylogenetic analysis clearly demonstrated that strain ZYR 51^T belongs to the genus Gordonia and showed low level similarities (below 97 %) with all other members of this genus. The strain was found to possess meso-diaminopimelic acid (meso-DAP), along with MK-9(H₂) as the predominant menaquonine. Mycolic acids were found to be present. C_16:0 (34.9 %), 10-methyl C_18:0 (30.3 %), iso-C_18:0(8.2 %), and summed feature 3 (C_16:1 ω6c and/or C_16:1ω7c as define by MIDI; 18.8 %) were identified as the major cellular fatty acids. The polar lipid profile of strain ZYR 51^T was found to consist of diphosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannosides and some unknown lipids. The genomic DNA G+C content of strain ZYR 51^T was determined to be 67.7 mol%. The combined genotypic and phenotypic data showed that the strain represents a novel species of the genus Gordonia, for which the name Gordonia jinhuaensis sp. nov. is proposed, with the type strain is ZYR 51^T (=CGMCC 1.12827^T = NBRL B-59111^T = NBRC 110001^T).