Cellular neoplastic transformation induced by 916 MHz microwave radiation

There has been growing concern about the possibility of adverse health effects resulting from exposure to microwave radiations, such as those emitted by mobile phones. The purpose of this study was to investigate the cellular neoplastic transformation effects of electromagnetic fields. 916 MHz continuous microwave was employed in our study to simulate the electromagnetic radiation of mobile phone. NIH/3T3 cells were adopted in our experiment due to their sensitivity to carcinogen or cancer promoter in environment. They were divided randomly into one control group and three microwave groups. The three microwave groups were exposed to 916 MHz EMF for 2 h per day with power density of 10, 50, and 90 w/m(2), respectively, in which 10 w/m(2) was close to intensity near the antenna of mobile phone. The morphology and proliferation of NIH/3T3 cells were examined and furthermore soft agar culture and animal carcinogenesis assay were carried out to determine the neoplastic promotion. Our experiments showed NIH/3T3 cells changed in morphology and proliferation after 5-8 weeks exposure and formed clone in soft agar culture after another 3-4 weeks depending on the exposure intensity. In the animal carcinogenesis study, lumps developed on the back of SCID mice after being inoculated into exposed NIH/3T3 cells for more than 4 weeks. The results indicate that microwave radiation can promote neoplastic transformation of NIH/3T3cells.     

Genetic variation and differentiation of Gekko gecko from different populations based on mitochondrial cytochrome b gene sequences and karyotypes

Black-spotted and red-spotted tokay geckos are distributed in different regions and have significant differences in morphological appearance, but have been regarded as the same species, Gekko gecko, in taxonomy. To determine whether black-spotted and red-spotted tokay geckos are genetically differentiated, we sequenced the entire mitochondrial cytochrome b gene (1147 bp) from 110 individuals of Gekko gecko collected in 11 areas including Guangxi China, Yunnan China, Vietnam, and Laos. In addition, we performed karyotypic analyses of black-spotted tokay geckos from Guangxi China and red-spotted tokay geckos from Laos. These phylogenetic analyses showed that black-spotted and red-spotted tokay geckos are divided into two branches in molecular phylogenetic trees. The average genetic distances are as follows: 0.12-0.47% among six haplotypes in the black-spotted tokay gecko group, 0.12-1.66% among five haplotypes in the red-spotted tokay gecko group, and 8.76-9.18% between the black-spotted and red-spotted tokay geckos, respectively. The karyotypic analyses showed that the karyotype formula is 2n = 38 = 8m + 2sm + 2st + 26t in red-spotted tokay geckos from Laos compared with 2n = 38 = 8m + 2sm + 28t in black-spotted tokay geckos from Guangxi China. The differences in these two kinds of karyotypes were detected on the 15th chromosome. The clear differences in genetic levels between black-spotted and red-spotted tokay geckos suggest a significant level of genetic differentiation between the two.     

METCAM/MUC18 augments migration, invasion, and tumorigenicity of human breast cancer SK-BR-3 cells

Previous research has identified METCAM/MUC18, an integral membrane cell adhesion molecule (CAM) in the Ig-like gene super-family, as a promoter or a suppressor in the development of human breast cancer by MCF7, MDA-MB-231, and MDA-MB-468. To resolve these conflicting results we have investigated the role of this CAM in the progression of the three aforementioned cell lines plus one additional human breast cancer cell line, SK-BR-3. We transfected the SK-BR-3 cells with human METCAM/MUC18 cDNA to obtain G418-resistant clones, which expressed different levels of the protein and which were used to test the effect of human METCAM/MUC18 expression on in vitro motility, invasiveness, anchorage-independent colony formation in soft agar, disorganized growth in a 3D basement membrane culture assay, and in vivo tumorigenesis in athymic nude mice. Enforced METCAM/MUC18 expression increased in vitro motility, invasiveness, and anchorage-independent colony formation of SK-BR-3 cells and favored disorganized growth of the cells in 3D basement membrane culture. Enforced expression also increased tumorigenicity and final tumor weights of SK-BR-3 clones/cells after subcutaneous injection of the cells under the left third nipple of female athymic nude mice. To understand the mechanisms, we also determined the expression of several downstream key effectors in the tumors. Tumor cells from METCAM/MUC18 expressing clones exhibited elevated expression of an anti-apoptotic and survival index (Bcl2), an aerobic glycolysis index (LDH-A), and pro-angiogenesis indexes (VEGF and VAGFR2). We concluded that human METCAM/MUC18 promotes the development of breast cancer cells by increasing an anti-apoptosis and survival pathway and augmenting aerobic glycolysis and angiogenesis.     

Single-cell exome sequencing reveals single-nucleotide mutation characteristics of a kidney tumor

Clear cell renal cell carcinoma (ccRCC) is the most common kidney cancer and has very few mutations that are shared between different patients. To better understand the intratumoral genetics underlying mutations of ccRCC, we carried out single-cell exome sequencing on a ccRCC tumor and its adjacent kidney tissue. Our data indicate that this tumor was unlikely to have resulted from mutations in VHL and PBRM1. Quantitative population genetic analysis indicates that the tumor did not contain any significant clonal subpopulations and also showed that mutations that had different allele frequencies within the population also had different mutation spectrums. Analyses of these data allowed us to delineate a detailed intratumoral genetic landscape at a single-cell level. Our pilot study demonstrates that ccRCC may be more genetically complex than previously thought and provides information that can lead to new ways to investigate individual tumors, with the aim of developing more effective cellular targeted therapies.     

A diet rich in n-3 polyunsaturated fatty acids reduced prostaglandin biosynthesis, ovulation rate, and litter size in mice

Successful cryopreservation is usually measured in terms of cell survival. However, there may also be more subtle effects within cells that survive. Previous studies on zebrafish have produced evidence of mitochondrial DNA (mtDNA) damage in cryopreserved embryonic blastomeres and, after exposure to cryoprotectants, alterations in mtDNA replication in embryos and decreased mitochondrial membrane potential, mtDNA and ATP production in ovarian follicles. This study shows that the decreased ATP levels previously observed in stage III zebrafish ovarian follicles exposed to ≥3 M methanol persisted in those follicles that subsequently developed to stage IV. However, the decreased mtDNA levels were restored in those follicles. In order to determine whether mitochondrial distribution and/or their transport network was affected by the methanol exposure, immunocytochemistry analysis of tubulin and mitochondrial cytochrome c oxidase I (COX-I) was performed, along with phalloidin staining of polymerized actin. Neat arrangements of all proteins were observed in control follicles, with COX-I and tubulin being colocalized near granulosa cell nuclei, while actin formed hexagonal and/or polygonal structures nearer granulosa cell membranes and projected into the oocyte surface. Exposure to methanol (2 to 4 M) disrupted the COX-I and tubulin arrangements and the hexagonal and/or polygonal actin distribution and actin projections into the oocyte. These effects were still observed in those follicles that developed to stage IV, although the severity was reduced. In summary, the disruption to function and distribution of mitochondria in ovarian follicles exposed to > 2 M methanol may be mediated via disruption of the mitochondrial transport system. Some recovery of this disruption may take place after methanol removal and subsequent follicle maturation.     

SlyA regulates type III secretion system (T3SS) genes in parallel with the T3SS master regulator HrpL in Dickeya dadantii 3937

The hypersensitive response and pathogenicity (hrp) genes of Dickeya dadantii 3937 encode a type III secretion system (T3SS) which is essential for its full virulence. Previous studies of the T3SS regulation in D. dadantii 3937 revealed that the expression of the hrp genes is regulated by a master regulator, HrpL, through the HrpX-HrpY-HrpS-HrpL and GacS-GacA-rsmB-RsmA pathways. In this work, we identified a novel regulator of the SlyA/MarR family, SlyA, which regulates hrp genes of the HrpL regulon in parallel with HrpL in D. dadantii. SlyA regulates the T3SS in a two-tier manner. It negatively regulates the expression of hrpL by downregulating hrpS and upregulating rsmA. Interestingly, concomitant with its downregulation of the hrpL, SlyA positively regulates the expression of hrpA and hrpN, two hrp genes located in the HrpL regulon. In contrast to Pectobacterium carotovorum, the expression of slyA is not controlled by ExpR and ExpI in D. dadantii 3937. We further show that SlyA is involved in controlling swimming motility and pellicle formation in D. dadantii 3937.     

Identification and Characterization of a Bile Salt Hydrolase from Lactobacillus salivarius for Development of Novel Alternatives to Antibiotic Growth Promoters

Antibiotic growth promoters (AGPs) have been used as feed additives to improve average body weight gain and feed efficiency in food animals for more than 5 decades. However, there is a worldwide trend to limit AGP use to protect food safety and public health, which raises an urgent need to discover effective alternatives to AGPs. The growth-promoting effect of AGPs has been shown to be highly correlated with the decreased activity of intestinal bile salt hydrolase (BSH), an enzyme that is produced by various gut microflora and involved in host lipid metabolism. Thus, BSH inhibitors are likely promising feed additives to AGPs to improve animal growth performance. In this study, the genome of Lactobacillus salivarius NRRL B-30514, a BSH-producing strain isolated from chicken, was sequenced by a 454 GS FLX sequencer. A BSH gene identified by genome analysis was cloned and expressed in an Escherichia coli expression system for enzymatic analyses. The BSH displayed efficient hydrolysis activity for both glycoconjugated and tauroconjugated bile salts, with slightly higher catalytic efficiencies (k_cat/K_m) on glycoconjugated bile salts. The optimal pH and temperature for the BSH activity were 5.5 and 41°C, respectively. Examination of a panel of dietary compounds using the purified BSH identified some potent BSH inhibitors, in which copper and zinc have been recently demonstrated to promote feed digestion and body weight gain in different food animals. In sum, this study identified and characterized a BSH with broad substrate specificity from a chicken L. salivarius strain and established a solid platform for us to discover novel BSH inhibitors, the promising feed additives to replace AGPs for enhancing the productivity and sustainability of food animals.     

Monitoring vegetation recovery after China’s May 2008 Wenchuan earthquake using Landsat TM time-series data: a case study in Mao County

The Wenchuan earthquake (Richter scale 8) on 12 May 2008 in southwestern China caused widespread ecosystem damage in the Longmenshan area. It is important to evaluate natural vegetation recovery processes and provide basic information on ecological aspects of the recovering environment after the earthquake. To circumvent the weather limits of remote sensing in the Wenchuan earthquake-hit areas, and to meet the need for regional observation analyses, three Landsat TM images pre- and post-earthquake in Mao County were used for analysis. Post-earthquake normalized difference vegetation index (NDVI) values were compared to pre-earthquake values with an NDVI-based index differencing method to determine the extent to which the vegetation was damaged in relation to the pre-earthquake pattern, and the rate of recovery was evaluated. The spatial characteristics of vegetation loss and natural recovery patterns were analyzed in relation to elevation, slope and aspect. The results indicated that severely damaged sites occurred mainly in river valleys, within a range of 1,500?C2,500?m elevation and on slopes of 25?C55°. The distance from rivers, rather than the distance from active faults, controls the damage patterns. After 1?year of natural regeneration, 36?% of the destroyed areas showed a decrease in NDVI value, 28.8?% showed very little change, 19.1?% showed an increase, and 16.1?% also increased with a recovery rate greater than 100?%. Moreover, there is a good correlation between recovery rate and both slope and elevation, but recovery patterns in the damaged area are complicated. Our results indicate that natural recovery in this arid valley is a slow process.