Targeting of Mcl-1 Expression by MiRNA-3614-5p Promotes Cell Apoptosis of Human Prostate Cancer Cells.

MicroRNA (miRNA) acts as a critical regulator of growth in various human malignancies. However, the role of miRNA-3614 in the progression of human prostate cancer remains unknown. In this study, our results demonstrated that miRNA-3614-5p exerts a significant inhibitory effect on cell viability and colony formation and induces sub-G1 cell cycle arrest and apoptosis in human prostate cancer cells. Myeloid cell leukemia-1 (Mcl-1) acts as a master regulator of cell survival. Using the miRNA databases, miRNA-3614-5p was found to regulate Mcl-1 expression by targeting positions of the Mcl-1-3' UTR. The reduction of Mcl-1 expression by miRNA-3614-5p was further confirmed using an immunoblotting assay. Pro-apoptotic caspase-3 and poly (ADP-ribose) polymerase (PARP) were significantly activated by miRNA-3614-5p to generate cleaved caspase-3 (active caspase-3) and cleaved PARP (active PARP), accompanied by the inhibited Mcl-1 expression. These findings were the first to demonstrate the anti-growth effects of miRNA-3614-5p through downregulating Mcl-1 expression in human prostate cancer cells.

[Secondary Aerosol Formation in Urban Shanghai: Insights into the Roles of Photochemical Oxidation and Aqueous-Phase Reaction].

Secondary species are one of the most important components of PM1 particles. To investigate the contributions as well as the factors that affect the formation of the secondary aerosols, a high-resolution time-of-flight aerosol mass spectrometer (HR-TOF-AMS, AMS) was employed to characterize sub-micron particles (PM1) during spring and summer in urban Shanghai. Organics were dominant in PM1 particles and comprised around 55% of the total PM1 mass concentration, followed by sulfate (24%) and nitrate (10%). Positive matrix factorization was further applied to explore the sources of the organics. It was found that primary and secondary organic aerosols accounted for around 34% and 66% of the total organics, respectively. Three episodes were observed during the measurements, where secondary species increased substantially. Increases of secondary species were represented by increases of sulfate and LV-OOA1 in spring, especially during the noontime, thus indicating that their formation is promoted by photochemical oxidation; yet in summer, photochemical and aqueous chemistry together accelerate the formation of secondary species, as indicated by the good correlations between nitrate and aerosol liquid water as well as between SOA and Ox. Overall, we found that contributions from secondary organic and inorganic aerosols to total PM1 particles were 35.5% and 43%, respectively. This study highlights that the influence of photochemical and aqueous chemistry is significant in the promotion of secondary species formation in Shanghai.

[Analysis of Non-polar Organic Compounds in PM2.5 by Rapid Thermo-desorption Method Coupled with GC/MS].

Non-polar organic compounds (NPOCs) associated with PM2.5 in the atmosphere were analyzed by automated thermo-desorption (TD) coupled with gas chromatography/mass spectrometry (TD-GC/MS). The analyses for a total of 72 NPOCs were reviewed, including 34 PAHs, one Debenzothiophene, 27 alkanes (C10-C34), 5 hopanes and 5 steranes. Through this improved TD method, operation of filter loadings, TD condition and sample introduction were optimized. The MDL were 0.01-1.0, 0.1-8.0 and 0.50-2.0 ng·m-3 for PAHs, alkanes, hopanes and steranes, respectively. Calibration curve linearities were above 0.9 for all compounds. The TD efficiencies were 95%-100% for PAHs, 81%-100% for alkanes and 83.1%-100% for hopanes and steranes. PM2.5 samples were pretreated by TD and ultrasonic extraction methods separately and analyzed by GC/MS in two laboratories. Results from these two methods were comparable, as the relative biases were less than 30% for most compounds. Analysis results of PM2.5 samples from Linan and Shanghai showed that NPOCs were higher in winter than that in summer. Alkanes were predominant among NPOCs, followed by PAHs. Source analysis by PAH characteristic ratios indicated that fossil fuel burning and coal burning were the main sources of NPOCs in the two sites during the sampling periods.

[Chemical Characterization, Spatial Distribution, and Source Identification of Organic Matter in PM2.5 in summertime Shanghai, China].

Particulate organic matter (POM) has attracted increasing attention recently due to its great contribution to fine particles (PM2.5) and complex components and sources. In the present study, 78 particulate organic compounds in PM2.5 were quantified at three sites in Shanghai during summer; these sites were located in urban (Xuhui), suburban (Qingpu), and coastal (Lin'gang) areas of the city. Accordingly, the chemical composition and spatial distribution were investigated and sources were explored based on the indicators and diagnostic ratios combined with backward trajectory. The results showed that during the period of observation, the quantified organic matter in the suburban area is about 319 ng ·m-3, close to the urban area but much higher than that of the coastal areas. Fatty acids were the largest contributors, followed by levoglucosan, polycyclic aromatic hydrocarbons (PAHs), n-alkanes, and hopanes. Source analysis based on tracer methods indicates that gasoline vehicle emissions were the main source of POM in Shanghai. Biomass burning from the northeast impacted somewhat on the urban area and western suburbs during the observation period. Terrestrial plant emissions played an important role in the source of fatty acids at Qingpu and Lin'gang, and emissions of marine phytoplankton and microorganisms were also important for fatty acids at Lin'gang. Coal combustion and motor vehicle exhaust made an important contribution to PAHs according to an analysis of diagnostic ratios. This study presented the characteristics and sources of POM in summertime Shanghai, which facilitates the development of an effective control strategy on PM2.5 pollution.

[Secondary organic tracers in summer PM2.5 aerosols from Baima Spring Scenic Area, Yaan, Sichuan Province].

Integrated PM2.5 aerosol samples were collected at Baima Spring Scenic Area, a forest site of Yaan, Sichuan Province, during the summer of 2010. Organic speciation including isoprene oxidation products (2-methyltetrols, C5-alkene trols, 2-methylyceric acid), alpha-/beta-pinene oxidation products (norpinic acid, 3-hydroxyglutaric acid, 3-methy-1,2,3-butanetricarboxylic acid), and small molecular carboxylic acid (malic acid, 2-hydroxyglutaric acid) were analyzed. The generation mechanisms of SOA as well as their influencing factors were particularly discussed. Results show that average concentrations of 2-methyltetrols, C5-alkene triols, 2-methyglyceric acid, norpinic acid, 3-hydroxyglutaric acid and 3-methy-1,2,3-butanetricarboxylic acid are 63.3, 45.0, 4.4, 4.1, 5.0, 5.3 ng x m(-3) respectively, of 24-hour lapse samples. SOA compounds are consistent with higher concentrations in the day than during the night only except for norpinic acid. Relatively high level of biogenic SOA at the study area is concerned with many environmental factors, i. e. local abundant vegetations, warm and humid climate, sunken valley topography, the atmospheric pollution state, etc.

Concentrations and seasonal variations of polybrominated diphenyl ethers (PBDEs) in in- and out-house dust and human daily intake via dust ingestion corrected with bioaccessibility of PBDEs.

The objective of this study was to investigate the concentrations, seasonal variations, bioaccessibility, and associated human daily intake of polybrominated diphenyl ethers (PBDEs) in in- and out-house dust collected in Shanghai, China. The PBDE concentrations varied from 131.6 to 3,886.7 ng g(-1) (with an average of 948.2 ng g(-1)) in in-house dust and from 8.7 to 3,116.3 ng g(-1) (with an average of 290.8 ng g(-1)) in out-house dust during four seasons. The PBDE concentrations in the autumn were the lowest for both in- and out-house dust. Among the detected PBDEs, BDE209 was the predominant congener, accounting for more than 80% of the total PBDE amounts. The bioaccessibility of PBDEs, measured using a simulation system of human gastrointestinal tract, was determined as 14.2-66.4% depending on individual PBDE congeners and showed significant negative correlations with organic matter in dust. After corrected with the bioaccessibility of PBDEs, the human daily intake of PBDEs via dust ingestion was calculated to be 0.4-21.4 and 4.3-40.6 ng day(-1) for an average adult and child in Shanghai, respectively. The values were much lower than most estimates in the literature, in which the bioaccessibility of PBDEs were not taken into account, suggesting that the intake of PBDEs may have been overestimated.

[Characteristics and influencing factors of carbonaceous aerosols in PM2.5 in Shanghai, China].

Organic carbon (OC) and elemental carbon (EC) in PM2.5 samples collected in urban (Xujiahui) and industrial (Baoshan) areas in Shanghai during 2007-2008 were analyzed with a DRI carbon analyzer using IMPROVE-TOR protocol. The results showed that the seasonal average concentrations of OC and EC were highest in the winter and lowest in the summer. The annual average concentrations of OC and EC were 8.10 and 3.91 microg x m(-3) at the urban sampling site, and 11.91 and 4.69 microg x m(-3) in the industrial area. The annual average OC/EC ratios at the two sites were 2.01 and 2.42, respectively. Strong correlations (R2 0.52-0.87) between OC and EC were found in all seasons, with the highest correlation coefficients in the winter ( R2 0.87 and 0.80) and the lowest in the spring (R2 0.52 and 0.58), indicating that the pollutant sources in spring was more complicated due to the varying wind directions. The annual average concentrations of secondary organic carbon (SOC) were 2.72 and 5.07 microg x m(-3) at the urban and industrial sites, accounting for about 30% of the total OC. The contribution of SOC to OC was the highest (about 40%) in the summer, in accordance with the high temperature and strong solar radiation in the summer. It was also found that precipitation had significant impact on the concentrations of OC and EC, especially in the winter. The average concentrations during periods without precipitation were two times higher than that during periods with precipitation in the winter, whereas no significant difference was found between the concentrations of OC and EC in the periods with and without precipitation in the summer, possibly due to the more stable atmospheric conditions during the periods with precipitation in comparison with those without precipitation. The OC/EC and SOC/OC ratios decreased significantly during precipitation.

[Indoor deposition flux and congener profiles of polybrominated diphenyl ethers (PBDEs) in Shanghai, China].

Indoor dry deposition of eight homes and offices in the urban area of Shanghai, China were sampled with clean glass plate during July to August of 2008 to study the indoor deposition flux and congener profiles of polybrominated diphenyl ethers (PBDEs). 16 PBDEs congeners which including BDE-17, -28, -71, 47, -66, -77, -100, -99, -85, -118, -154, -153, -138, -183, -190 and BDE-209 were measured by GC-MS with negative chemical ionization (NCI) in selected ion monitoring (SIM) mode. The particulate deposition flux of PBDEs in homes and offices were (10.9 +/- 8.2) and (14.2 +/- 11.9) ng x (m2 x d)(-1) respectively. Deca-BDE (BDE-209) was the major compound, accounting for 88.2% -99.2% of the quantified PBDEs. The particulate deposition flux in the offices [(3.1 +/- 2.0) mg x (m2 x d)(-1)] was relatively lower than that of homes, but the concentration of PBDEs in the particles [(3361.6 +/- 1987.4) ng x g(-1)] was significantly higher than that of homes [(1169.1 +/- 647.1) ng x g(-1)]. The concentration of PBDEs in the indoor dry deposition of Shanghai ranked in the middle level comparing with other cities around the world. The indoor deposition flux of PBDEs was mainly correlated with the flux of particle deposition and the usage of electrical and electronic products, but not the interior decoration and the amount of furniture.

Determination of gaseous carbonyl compounds by their pentafluorophenyl hydrazones with gas chromatography/mass spectrometry.

A sensitive and reliable method has been developed for the simultaneous determination of 20 airborne carbonyl compounds in the C(1)-C(10) range. The carbonyls were collected onto solid sorbent coated with pentafluorophenyl hydrazine (PFPH), followed by solvent extraction and gas chromatographic (GC)/mass spectrometric (MS) analysis of the PFPH derivatives. The sorbent is packed into two separate sections in a glass sampling tube. The two-section design allows convenient checking of collection efficiency and breakthrough. The sampling tube, with a coating amount of 971 nmol PFPH per 100 mg Tenax TA and operated at a sampling flow rate of 80 mL min(-1), collects the 20 carbonyls with efficiencies above 95%. Hexane extracts the collected carbonyls in their PFPH derivatives in the sampling tube with better than 95% extraction efficiency. It is necessary to let the sampling tube sit at ambient temperature for 3 days before solvent extraction to ensure complete derivatization of the carbonyls. The limits of detection (LODs) of the tested carbonyls are in the range of 3.7-11.6 ng per sample. The method has been field-tested both in ambient environment and in an indoor environment from burning mosquito-repellent incense. Eighteen carbonyls were detected in the ambient air samples with the exception of o-tolualdehyde and m-tolualdehyde, while all the 20 target carbonyls were found in the incense smoke. Compare field test with classical DNPH-HPLC/UV method, good agreement exited between the two methods for lower molecular carbonyls but PFPH method is found to be a better analytical method for determination of high molecular weight carbonyls.