Invasion and metastasis of solid tumors are the major causes of death in cancer patients. Cancer stem cells (CSCs) constitute a small fraction of tumor cell population, but play a critical role in tumor invasion and metastasis. The xenograft of tumor cells in immunodeficient mice is one of commonly used in vivo models to study the invasion and metastasis of cancer cells. However, this model is time-consuming and labor intensive. Zebrafish (Danio rerio) and their transparent embryos are emerging as a promising xenograft tumor model system for studies of tumor invasion. In this study, we established a tumor invasion model by using zebrafish embryo xenografted with human glioblastoma cell line U87 and its derived cancer stem cells (CSCs). We found that CSCs-enriched from U87 cells spreaded via the vessels within zebrafish embryos and such cells displayed an extremely high level of invasiveness which was associated with the up-regulated MMP-9 by CSCs. The invasion of glioma CSCs (GSCs) in zebrafish embryos was markedly inhibited by an MMP-9 inhibitor. Thus, our zebrafish embryo model is considered a cost-effective approach tostudies of the mechanisms underlying the invasion of CSCs and suitable for high-throughput screening of novel anti-tumor invasion/metastasis agents.
A PCR-restriction fragment length polymorphism method for identification of cry1I-type genes from Bacillus thuringiensis was established by designing a pair of universal primers based on the conserved regions of the genes to amplify 1,548-bp cry1I-type gene fragments. Amplification products were digested with the Bsp119I and BanI enzymes, and four kinds of known cry1I-type genes were successfully identified. The results showed that cry1I-type genes appeared in 95 of 115 B. thuringiensis isolates and 7 of 13 standard strains. A novel cry1I-type gene was found in one standard strain and six isolates. The novel cry1I gene was cloned from B. thuringiensis isolate Btc007 and subcloned into vector pET-21b. Then it was overexpressed in Escherichia coli BL21(DE3). The expressed product was shown to be toxic to the diamondback moth (Plutella xylostella), Asian corn borer (Ostrinia furnacalis), and soybean pod borer (Leguminivora glycinivorella). However, it was not toxic to the cotton bollworm (Helicoverpa armigera), beet armyworm (Spodoptera exigua), or elm leaf beetle (Pyrrhalta aenescens) in bioassays. Subsequently, the Cry protein encoded by this novel cry gene was designated Cry1Ie1 by the B. thuringiensis ␦-endotoxin nomenclature committee.Crystal proteins from the gram-positive spore-forming bacterium Bacillus thuringiensis are toxic to a wide variety of insects that are economically important as pests. Many different genes encoding the B. thuringiensis endotoxin have been isolated and characterized. The genes have been classified as cry1 to cry40, cyt1, and cyt2 and are ranked according to their homology (10, 21; see also the B. thuringiensis toxin nomenclature website at http://www.biols.susx.ac.uk/home/Neil_Crickmore /Bt/). Cry1 proteins that are active against lepidopteran insects are produced as crystalline parasporal inclusions during sporulation. Generally, the crystals are composed of protoxins of approximately 130 kDa, but cry1I-type genes are usually silent genes capable of encoding a protein of about 81 kDa in B. thuringiensis strains (9,13,21,24). We decided to screen B. thuringiensis isolates for cry1I genes with the aim of finding novel cry1I genes, which could encode insecticidal proteins toxic to insensitive or resistant insect pests.This screening approach included the development of an analysis protocol based on PCR-restriction fragment length polymorphism (RFLP). PCR-based methods have been developed to detect different cry genes from B. thuringiensis strains (1-8, 11, 13, 15, 17, 23). More than 80 primer pairs have been designed to identify entire groups and individual cry genes (19). Several specific primers and probes for Southern blotting were designed to detect cry1I-type genes. A wide distribution of cry1I-type genes among many different B. thuringiensis strains has been reported (13,22,25). However, the list of cry genes is increasing, and novel PCR primers are needed in order to identify some of the recently described genes (5).The present study establishes a PCR-RFLP method for identify...
A highly virulent cotton wilt pathogen, Fusarium oxysporum f. sp. vasinfectum VCG0114 (race 4) was found in West Texas in 2017, after being known in California since 2001. Isolates obtained from wilted plants collected in 2017 from Texas, in 2015 from China, and during 2001 to 2014 from California and isolates from historical collections including the race 4 reference isolate were characterized by soil-infestation pathogenicity assays, DNA sequence analysis, and vegetative compatibility analysis. All obtained F. oxysporum f. sp. vasinfectum isolates belonged to VCG0114. All of these isolates, except one isolate from China, caused disease in a soil-infestation assay without nematodes. Thus, they belong to the nematode-independent pathotype. Texas isolates were significantly more virulent than were isolates from China or California on Gossypium barbadense ‘Pima S-7’. Four different genotypes (N, T, MT, and MiT) were identified based on the transposable element Tfo1 insertion into the PHO gene and independent MULE or MITE insertions into the Tfo1 transposon. Some significant differences in virulence were detected among the genotypes in some locations. No differences in pathogenicity were observed between the California and China collection isolates on Pima S-7, and the virulence of the major genotypes was similar on the Gossypium hirsutum cultivar ‘Stoneville 474’ or the Barbren 713 germplasm line. Simple polymerase chain reaction (PCR) methods were developed to specifically determine and detect the four genotypes within VCG0114. A specific PCR method to detect all VCG0114 isolates was also developed. These methods will facilitate the timely identification of infested fields and seed lots and the elucidation of evolutionary relationships among the isolates. This should help to closely monitor the movement of the pathogen and reduce dissemination of these devastating pathogens.
In previously untreated, advanced NSCLC patients, treatment with TC plus endostar seemed to improve ORR. However, the differences in PFS or OS between the two groups were not statistically significant. Treatment with TC plus endostar exhibited a good safety profile.
MicroRNAs (miRNAs) are involved in human cancer including non-small cell lung cancer (NSCLC). In this study, we compared miRNA expression microarray of SPC-A-1sci (high metastatic) and SPC-A-1 (weakly metastatic) cells. We found that miRNA-10a was up-regulated in NSCLC compared with corresponding normal tissues. High expression of miR-10a was associated with tumor node metastasis and lymph node metastasis. Furthermore, overexpression of miR-10a promoted NSCLC cell proliferation, migration and invasion in vitro. We found that PTEN was a direct target of miR-10a in NSCLC. Also miR-10a activated the PTEN/AKT/ERK pathway. We suggest that miR-10a contributes to NSCLC by targeting PTEN.
Neoadjuvant erlotinib was well tolerated and may improve the radical resection rate in this patient population. Next-generation sequencing may predict outcomes with preoperative TKIs.
Abstract. Knowledge of aerosol chemistry in densely populated regions is critical for effective reduction of air pollution, while such studies have not been conducted in Changzhou, an important manufacturing base and populated city in the Yangtze River Delta (YRD), China. This work, for the first time, performed a thorough chemical characterization on the fine particulate matter (PM 2.5 ) samples, collected during July 2015 to April 2016 across four seasons in this city. A suite of analytical techniques was employed to measure the organic carbon (OC), elemental carbon (EC), watersoluble organic carbon (WSOC), water-soluble inorganic ions (WSIIs), trace elements, and polycyclic aromatic hydrocarbons (PAHs) in PM 2.5 ; in particular, an Aerodyne soot particle aerosol mass spectrometer (SP-AMS) was deployed to probe the chemical properties of water-soluble organic aerosol (WSOA). The average PM 2.5 concentration was found to be 108.3 µg m −3 , and all identified species were able to reconstruct ∼ 80 % of the PM 2.5 mass. The WSIIs occupied about half of the PM 2.5 mass (∼ 52.1 %), with SO 2− 4 , NO − 3 , and NH + 4 as the major ions. On average, nitrate concentrations dominated over sulfate (mass ratio of 1.21), indicating that traffic emissions were more important than stationary sources. OC and EC correlated well with each other and the highest OC / EC ratio (5.16) occurred in winter, suggesting complex OC sources likely including both secondary and primary ones. Concentrations of eight trace elements (Mn, Zn, Al, B, Cr, Cu, Fe, Pb) can contribute up to ∼ 5.0 % of PM 2.5 during winter. PAH concentrations were also high in winter (140.25 ng m −3 ), which were predominated by median/high molecular weight PAHs with five and six rings. The organic matter including both watersoluble and water-insoluble species occupied ∼ 21.5 % of the PM 2.5 mass. SP-AMS determined that the WSOA had average atomic oxygen-to-carbon (O / C), hydrogen-to-carbon (H / C), nitrogen-to-carbon (N / C), and organic matter-toorganic carbon (OM / OC) ratios of 0.54, 1.69, 0.11, and 1.99, respectively. Source apportionment of WSOA further identified two secondary OA (SOA) factors (a less oxidized and a more oxidized oxygenated OA) and two primary OA (POA) factors (a nitrogen-enriched hydrocarbon-like traffic OA and a local primary OA likely including species from cooking, coal combustion, etc.). On average, the POA contribution outweighed SOA (55 % vs. 45 %), indicating the important role of local anthropogenic emissions in the aerosol pollution in Changzhou. Our measurement also shows the abundance of organic nitrogen species in WSOA, and the source analyses suggest these species are likely associated with traffic emissions, which warrants more investigations on PM samples from other locations.
Although the specificity of AFB + WLB is lower than WLB alone, AFB + WLB seems to significantly improve the sensitivity to detect intraepithelial neoplasia. However, this advantage over WLB alone seems much less in detecting invasive lung cancer.
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