Associations of Plasma Fatty Acid Patterns During Pregnancy With Gestational Diabetes Mellitus.

Background: Limited studies have explored the difference of fatty acid profile between women with and without gestational diabetes mellitus (GDM), and the results were inconsistent. Individual fatty acids tend to be interrelated because of the shared food sources and metabolic pathways. Thus, whether fatty acid patters during pregnancy were related to GDM odds needs further exploration. Objective: To identify plasma fatty acid patters during pregnancy and their associations with odds of GDM. Methods: A hospital-based case-control study including 217 GDM cases and 217 matched controls was carried out in urban Wuhan, China from August 2012 to April 2015. All the participants were enrolled at the time of GDM screening and provided fasting blood samples with informed consent. We measured plasma concentrations of fatty acids by gas chromatography-mass spectrometry, and derived potential fatty acid patterns (FAPs) through principal components analysis. Conditional logistic regression and restricted cubic spline model were used to evaluate the associations between individual fatty acids or FAPs and odds of GDM. Results: Twenty individual fatty acids with relative concentrations ≥0.05% were included in the analyses. Compared with control group, GDM group had significantly higher concentrations of total fatty acids, 24:1n-9, and relatively lower levels of 14:0, 15:0, 17:0, 18:0, 24:0, 16:1n-7, 20:1n-9,18:3n-6, 20:2n-6, 18:3n-3, 20:3n-3, 22:5n-3. Two novel patterns of fatty acids were identified to be associated with lower odds of GDM: (1) relatively higher odd-chain fatty acids, 14:0, 18:0, 18:3n-3, 20:2n-6, 20:3n-6 and lower 24:1n-9 and 18:2n-6 [adjusted odds ratio (OR) (95% confidence interval) (CI) for quartiles 4 vs. 1: 0.42 (0.23-0.76), P-trend = 0.002], (2) relatively higher n-3 polyunsaturated fatty acids, 24:0, 18:3n-6 and lower 16:0 and 20:4n-6 [adjusted OR (95% CI) for quartiles 4 vs. 1: 0.48 (0.26-0.90), P-trend = 0.018]. Conclusion: Our findings suggested that two novel FAPs were inversely associated with GDM odds. The combination of circulating fatty acids could be a more significant marker of GDM development than individual fatty acids or their subgroups.

Association of Gut Microbiota-Dependent Metabolite Trimethylamine N-Oxide with First Ischemic Stroke.

AIM: We aimed to investigate the relationship of trimethylamine N-oxide (TMAO) concentrations with ischemic stroke in a large-scale case-control study conducted among the hospital-based general population. METHODS: We recruited 953 case-control sex- and age-matched pairs, and cases were confined to first acute ischemic stroke in this study. Fasting plasma TMAO was measured using high-performance liquid chromatography-tandem mass spectroscopy. Conditional logistic regression analysis was conducted to calculate odds ratios (OR) for the association of plasma TMAO with ischemic stroke. RESULTS: We found that plasma TMAO concentrations in patients with ischemic stroke were significantly higher than that in the control group (median: 2.85 µmol/L vs. 2.33 µmol/L, P＜0.001). In multivariable conditional logistic regression models, higher plasma TMAO concentrations were associated with increased odds of ischemic stroke [fully adjusted OR for highest vs. lowest TMAO quartile: 1.81; 95% confidence interval (CI): 1.27, 2.59; P for trend ＜0.001]. The multivariable-adjusted OR for ischemic stroke per 1 µmol/L increment of plasma TMAO was 1.05 (95% CI: 1.02, 1.08). Additionally, the positive association also persisted in subgroups stratified by age, sex, body mass index, smoking status, alcohol habits, history of diabetes, and history of hypertension. CONCLUSIONS: This study suggested a positive association between plasma TMAO and ischemic stroke. Further studies are required to explore the role of plasma TMAO concentrations in predicting stroke risk.

Oxidative damage mediates the association between polycyclic aromatic hydrocarbon exposure and lung function.

BACKGROUND: Exposure to polycyclic aromatic hydrocarbons (PAHs) is related to decreased lung function. However, whether oxidative damage is involved in this relationship remains unclear. This study was aimed to explore the potential mediating role of oxidative DNA or lipid damage in the association between PAH exposure and lung function. METHODS: The urinary levels of monohydroxy polycyclic aromatic hydrocarbon metabolites (OH-PAHs) and lung function parameters were measured among 3367 participants from the baseline of the Wuhan-Zhuhai cohort. Urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) and 8-isoprostane (8-iso-PGF2α) were determined to evaluate the individuals' oxidative DNA and lipid damage degrees, respectively. Linear mixed models were used to investigate the associations of urinary OH-PAHs, 8-OHdG and 8-iso-PGF2α with lung function parameters. Mediation analysis was further conducted to assess the potential role of oxidative damage in the association between urinary OH-PAHs and lung function. RESULTS: Each one-percentage increase in the sum of urinary OH-PAHs, high-molecular-weight or low-molecular-weight OH-PAHs (Æ©OH-PAHs, Æ©HMW OH-PAH or Æ©LMW OH-PAHs, respectively) was associated with a 0.2152-, 0.2076- or 0.1985- ml decrease in FEV1, and a 0.1891-, 0.2195- or 0.1634- ml decrease in FVC, respectively. Additionally, significantly positive dose-response relationships of Æ©OH-PAHs, Æ©HMW OH-PAH and Æ©LMW OH-PAHs with urinary 8-OHdG or 8-iso-PGF2α, as well as an inverse dose-response relationship between urinary 8-OHdG and FVC, were observed (all P for trend < 0.05). Mediation analysis indicated that urinary 8-OHdG mediated 14.22% of the association between Æ©HMW OH-PAH and FVC. CONCLUSION: Higher levels of oxidative DNA damage might be involved in the decreased levels of FVC caused by high-molecular-weight PAH exposure.

Cross-sectional and longitudinal associations between urinary zinc and lung function among urban adults in China.

BACKGROUND: Exposure to zinc was suggested to be associated with pulmonary damage, but whether zinc exposure affects lung function remains unclear. OBJECTIVES: To quantify the association between urinary zinc and lung function and explore the potential mechanisms. METHODS: Urinary zinc and lung function were measured in 3917 adults from the Wuhan-Zhuhai cohort and were repeated after 3 years of follow-up. Indicators of systemic inflammation (C reactive protein), lung epithelium integrity (club cell secretory protein-16) and oxidative damage (8-hydroxy-2'-deoxyguanosine and 8-isoprostane) were measured at baseline. Linear mixed models were used to estimate the exposure-response relationship between urinary zinc and lung function. Mediation analyses were conducted to assess mediating roles of inflammation and oxidative damage in above relationships. RESULTS: Each 1-unit increase in log-transformed urinary zinc values was associated with a 35.72 mL decrease in forced vital capacity (FVC) and a 24.89 mL decrease in forced expiratory volume in 1 s (FEV1) in the baseline analyses. In the follow-up analyses, there was a negative association between urinary zinc and FVC among participants with persistent high urinary zinc levels, with an estimated change of -93.31 mL (95% CI -178.47 to -8.14). Furthermore, urinary zinc was positively associated with restrictive ventilatory impairment. The mediation analyses suggested that C reactive protein mediated 8.62% and 8.71% of the associations of urinary zinc with FVC and FEV1, respectively. CONCLUSION: Urinary zinc was negatively associated with lung function, and the systemic inflammation may be one of the underlying mechanisms.

Diverse Associations of Plasma Selenium Concentrations and SELENOP Gene Polymorphism with Metabolic Syndrome and Its Components.

The relationship between selenium and metabolic syndrome (MetS) has been discussed controversially, and limited studies have examined the associations of single nucleotide polymorphisms in selenoproteins genes with MetS. Hence, to examine the associations of plasma selenium concentrations and selenoprotein P rs7579 polymorphism with MetS, a case-control study of 1279 MetS cases and 1279 sex- and age- (±2 years) matched controls was conducted based on the baseline data of the Tongji-Ezhou Cohort study. Plasma selenium concentrations were measured by inductively coupled plasma mass spectrometry. MetS was defined using the definition of the Joint Interim Statement, adjusted for the Chinese population. In addition, the rs7579 polymorphism was genotyped by the Agena MassARRAY System. Plasma selenium concentrations in the MetS group were higher than in the control group (93.88 µg/L (83.17-107.41) vs. 92.66 µg/L (82.36-103.53), P < 0.05). Compared with quartile 4 (≥103.53 µg/L), the multivariate-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) associated with MetS were 0.79 (0.59-1.06) for quartile 1 (<82.36 µg/L), 0.75 (0.56-1.01) for quartile 2 (82.37-92.66 µg/L), and 0.61 (0.45-0.83) for quartile 3 (92.67-103.52 µg/L). The cubic spline analyses revealed a U-shaped association between plasma selenium and MetS, with the lowest risk at around 93.69 µg/L. Moreover, in cubic spline analyses, plasma selenium showed U-shaped associations with central obesity and high blood pressure, positive associations with hypertriglyceridemia and hyperglycemia, and a negative association with low high-density lipoprotein cholesterol. Additionally, both the GA and GA+AA genotype carriers were associated with increased ORs of MetS comparing with the GG genotype carriers. Our findings suggested a U-shaped association between plasma selenium and MetS and diverse associations between plasma selenium and components of MetS. Furthermore, our study found that the A allele of rs7579 was associated with higher odds of MetS. Further studies are needed to confirm our findings and elucidate the underlying mechanisms.

Chronic acrylamide exposure induced glia cell activation, NLRP3 infl-ammasome upregulation and cognitive impairment.

Acrylamide (ACR), a potential neurotoxin, is present in diet and drinking water. Dietary exposure contributes to cognitive impairment, but relevant mechanism information is limited. Neuroinflammation plays important roles in neurodegenerative disorders. This study aimed to explore whether chronic acrylamide exposure induced neuronal lesions, microglial activation, NLRP3 inflammasome-mediated neuroinflammation and cognitive impairment. For this purpose, 36 Sprague-Dawley (SD) rats were randomly divided into three groups (n = 12/group) and maintained on treated drinking water providing dosages of 0, 0.5, or 5 mg/kg/day ACR for 12 months. Chronic exposure to ACR caused gait abnormality and cognitive dysfunction, which was associated with neuronal lesions, decrease in synapse associated proteins including synapsin I (SYN1), synaptophysin (SYP) and postsynaptic density protein 95 (PSD95), neurogenesis suppression as shown by reduced brain derived neurotrophic factor (BDNF) and doublecortin (DCX) in the hippocampus and frontal cortex. ACR stimulated glial proliferation and microglial activation by increasing GFAP+, Iba-1+, Iba-1+CD68+ positive cells. ACR markedly upregulated the protein levels of NLRP3 inflammasome constituents NLRP3, caspase-1 and increased pro-IL-1ß and IL-1ß. ACR elevated the protein P62 to suppress NLPR3 inflammasome cleavage. Inflammatory cytokines including TNF-α, IL-6 and Cox-2 were also significantly increased after NF-κB pathway activation, which aggravated neuronal lesions and caused memory deficits. This work helped to propose the possible mechanism of chronic exposure of ACR-induced neurotoxicity.

Association between plasma strontium, a bone-seeking element, and type 2 diabetes mellitus.

BACKGROUND & AIMS: Drinking water and food are the major sources of strontium in human. Strontium is essential for bone metabolism, while its role in glucose and lipid metabolism is largely unknown. We aimed to investigate the association of strontium, a bone-seeking element, with type 2 diabetes mellitus (T2DM) and impaired glucose regulation (IGR) and to further explore the potential mechanisms. METHODS: The case-control study included 1448 newly diagnosed T2DM patients, 782 IGR patients, and 2230 matched controls with normal glucose tolerance. Plasma strontium and other plasma minerals were quantified via inductively coupled plasma mass spectrometry. Multivariable logistic regression analysis was used to evaluate the independent associations between plasma strontium and T2DM and IGR. RESULTS: Plasma strontium was inversely associated with T2DM and IGR. After adjustment for sociodemographic, lifestyle factors, and multiple plasma metals, the odds ratios (95% confidence intervals) of T2DM and IGR were 0.45 (0.35-0.57) and 0.55 (0.43-0.71), respectively, comparing the highest to the lowest quartile of plasma strontium levels. In spline analysis, the odds of T2DM and IGR decreased remarkably with increasing strontium concentration and followed by a plateau. Additionally, plasma strontium was negatively associated with total cholesterol, low density lipoprotein cholesterol, and lipid peroxidation (plasma malondialdehyde level). CONCLUSIONS: The current study indicated that higher plasma strontium concentration was associated with lower odds of T2DM and IGR. Further studies are warranted to confirm these findings and to clarify the underlying mechanisms.

Effects of environmental and lifestyle exposures on urinary levels of polycyclic aromatic hydrocarbon metabolites: A cross-sectional study of urban adults in China.

Urinary polycyclic aromatic hydrocarbon (PAH) metabolites, biomarkers of internal PAH exposure, are commonly used to explore the effects of PAH on human health. However, the correlation between environmental PAH exposure and the species or levels of urinary PAH metabolites remains unclear. We collected detailed information on PAH exposure sources, including cigarette smoking, cooking, traffic and diet habits via structured questionnaires, and determined 12 urinary monohydroxylated PAH metabolites (OH-PAHs) among 4092 participants from the Wuhan-Zhuhai cohort. Linear mixed models and generalized linear models were conducted to explore the associations of urinary metabolite levels with single or multiple PAH exposure sources. We also calculated the standardized regression coefficients to further compare the contributions of different sources to urinary OH-PAH levels. Our results showed that increasing levels of urinary 1-, 2-hydroxynaphthalene (1-, 2- OHNa) and 2-hydroxyfluorene (2-OHFlu) were significantly correlated with tobacco smoking (all P < 0.01). The concentrations of 1-, 2- OHNa and 9-hydroxyfluorene (9-OHFlu) were positively correlated with dietary intake (all P < 0.05). Individuals who spent a long time in traffic showed elevated levels of 9-OHFlu and 1-hydroxyphenanthrene (1-OHPh) compared with individuals who spent a short time in traffic (all P < 0.05). Self-cooking was associated only with elevated 1-hydroxypyrene (1-OHP) levels. Moreover, good kitchen ventilation resulted in significantly decreased urinary low-molecular-weight OH-PAH levels. These findings suggested that cigarette smoking, self-cooking, high dietary PAH intake and a long time spent in traffic were associated with increased levels of specific urinary PAH metabolites, and good kitchen ventilation effectively reduced the exposure to low-molecular-weight PAHs in self-cooking participants.

Comparison of Intentional and Unintentional Injuries Among Chinese Children and Adolescents.

BACKGROUND: The patterns and risk factors of intentional injuries compared to unintentional injuries among Chinese children and adolescents have not been examined in depth. This work comprehensively describes patterns of intentional injuries in China, for which little information has been previously published. METHODS: All cases involving individuals 0-17 years old registered at emergency rooms and outpatient clinics were examined using data submitted to the National Injury Surveillance System from 2006 through 2017. A logistic regression model was performed to explore the risk factors related to intentional injuries compared to unintentional injuries. RESULTS: A total of 81,459 (95.1%) unintentional injuries, 4,218 (4.9%) intentional injuries (4,013 violent attacks and 205 self-mutilation/suicide) cases were identified. Blunt injuries accounted for 59.4% of violent attacks, while cuts and poisoning accounted for 37.1% and 23.4% of injuries involving self-mutilation/suicide, respectively. For unintentional injuries, falls (50.4%) ranked first. Additional risk factors for intentional injuries included being male (odds ratio [OR] 1.6), coming from rural areas (OR 1.9), being staff or workers (OR 2.2), and being a student (OR 1.8). As the age of the patients increased, so did the risk of intentional injuries (OR 5.0 in the 15-17 age group). Intentional injuries were more likely to occur at 00:00-03:00 am (OR 2.0). CONCLUSIONS: Intentional injuries affected more males, rural and older children, school students, and staff or workers. The mechanisms and occurrence times differed according to age group. Preventive measures should be taken to reduce the dropout of rural students, strengthen the school's violence prevention plan, and reduce self-harm.

Association of lung function with cardiovascular risk: a cohort study.

BACKGROUND: The potential effects of pulmonary dysfunction on cardiovascular diseases (CVD) are receiving attention. We aimed to investigate and quantify the cross-sectional and longitudinal associations between lung function and overall cardiovascular risk among Chinese general population. METHODS: We studied 4019 participants from the Wuhan-Zhuhai cohort, with a follow-up of 3 years. A multivariable risk algorithm generated from the Framingham study was used to calculate individuals' overall cardiovascular risk i.e. 10-Year CVD Risk, which was further classified into 2 categories: low (< 10%) and high (≥10%) CVD risk. General linear model and logistic regression model were separately used to assess the associations of lung function with continuous and dichotomous 10-Year CVD Risk. RESULTS: Cross-sectionally, each 5% decrease in FEV1/FVC was associated with a 0.47% increase in 10-Year CVD Risk (P < 0.001). The adjusted odds ratio (OR) (95% confidence interval [CI]) for the prevalence of high CVD risk (10-Year CVD Risk≥10%) was 1.12 (1.07, 1.17) corresponding to each 5% decrease in FEV1/FVC. The OR (95% CI) for high CVD risk in the lowest group of FEV1/FVC (< 70% i.e. chronic obstructive pulmonary disease [COPD]) was 2.37 (1.43, 3.91) when compared with the highest group. Longitudinally, the adjusted risk ratio (RR) (95% CI) for the incidence of high CVD risk was 1.14 (1.03, 1.25) with each 5% decrease in baseline FEV1/FVC. Compared with the highest group of FEV1/FVC, the RR (95% CI) for high CVD risk in the lowest group (COPD) was 4.06 (1.46, 11.26). Analyses of 10-Year CVD Risk with FVC or FEV1 showed similar trends and significant associations (all P < 0.05). CONCLUSION: Reduced lung function was cross-sectionally and longitudinally associated with increased cardiovascular risk in Chinese general population.

Urinary polycyclic aromatic hydrocarbon metabolites, Club cell secretory protein and lung function.

BACKGROUND: Exposure to polycyclic aromatic hydrocarbons (PAHs) has been associated with lung function decline. However, the underlying mechanisms for the association remain unclear. OBJECTIVES: To explore potential role of a lung epithelial biomarker, Club cell secretory protein (CC16), in associations between PAH exposures and lung function decline. METHODS: We investigated 3384 adults from the Wuhan-Zhuhai cohort, and followed up at three years after first examination. Linear mixed models was used to quantify dose-response relationships between urinary monohydroxylated PAH metabolites (OH-PAHs) and lung function, as well as OH-PAHs and plasma CC16. Mediation analysis was conducted to investigate role of CC16 in the association between OH-PAHs and lung function. We also estimated the relationships between OH-PAHs and lung function change in three years among participants with different levels of CC16. RESULTS: Each 1-unit increase of log-transformed total urinary high and low molecular weight OH-PAHs (∑HMW OH-PAH and ∑LMW OH-PAHs) were associated with a 22.59 and 25.25ml reduction of FEV1 respectively, while∑HMW OH-PAH was associated with a 30.38ml reduction of FVC. Moreover, these negative associations between OH-PAHs and lung function levels were significant only among low CC16 group (<15.83ng/ml). CC16 concentration decreased monotonically with increased high molecular weight OH-PAHs (∑HMW OH-PAHs) when ∑HMW OH-PAH concentration was over 0.67µg/mmol Cr. CC16 mediated 22.13% of the association between ∑HMW OH-PAH and FVC among individuals with higher ∑HMW OH-PAH. After three years of follow-up, subjects with low level of plasma CC16 had a significant decline of FVC when exposed to high level of ∑HMW OH-PAH. CONCLUSIONS: CC16 play an important role in the association between high molecular weight PAHs and FVC. Individuals with low plasma CC16 level might suffer a decline in lung function when exposed to high level of high molecular weight PAHs.

The Wuhan-Zhuhai (WHZH) cohort study of environmental air particulate matter and the pathogenesis of cardiopulmonary diseases: study design, methods and baseline characteristics of the cohort.

BACKGROUND: Particulate air pollution has been recognized to be associated with a wide range of adverse health effects, including increased mortality, morbidity, exacerbation of respiratory conditions. However, earlier physiological or pathological changes or long-term bodies' reaction to air pollutants have not been studied in depth in China. The Wuhan-Zhuhai (WHZH) cohort study is designed to investigate the association between air pollutants exposure and physiological or pathological reactions on respiratory and cardiovascular system. METHODS/DESIGN: The cohort is a community-based prospective study that includes 4812 individuals aged 18-80 years. The collections of data were conducted from April to May 2011 in Wuhan city and in May 2012 in Zhuhai city. At baseline, data on demographic and socioeconomic information, occupational history, family disease history, lifestyle, cooking mode, daily travel mode, physical activity and living condition have been collected by questionnaires. Participants underwent an extensive physical examination, including anthropometry, spirometry, electrocardiography, and measurements of blood pressure, heart rate, exhaled nitric oxide and carbon monoxide. Potential conditions in the lung, heart, liver, spleen, and skin were synchronously performed. In addition, samples of morning urine, fasting blood serum and plasma were collected during physical health examination. DNA were extracted and were stored at -80°C. Environment concentrations of particulate matter and chemicals were determined for 15 days in each of four seasons. Participants are followed for physiological or pathological changes or incidence of cardiopulmonary diseases every 3 years. DISCUSSION: The results obtained in WHZH cohort study may increase a better understanding of the relationship between particulate air pollution and its components and possible health damages. And the potential mechanisms underlying the development of cardiopulmonary diseases has implications for the development of prevention and treatment strategies.

Epidemiological analysis of respiratory viral etiology for influenza-like illness during 2010 in Zhuhai, China.

BACKGROUND: Influenza-like illnesses (ILI), a subset of acute respiratory infections (ARI), are a significant source of morbidity and mortality worldwide. ILI can be caused by numerous pathogens, however; there is limited information on the etiology and epidemiology of ILI in China. METHODS: We performed a one-year surveillance study (2010) of viral etiology causing ILI and investigated the influence of climate on outbreaks of ILI attributed to viruses at the Outpatient Department of Zhuhai Municipal People's Hospital in Zhuhai, China. RESULTS: Of the 337,272 outpatients who sought attention in the Outpatient Department of Zhuhai Municipal People's Hospital in 2010, 3,747 (1.11%) presented with ILI. Of these patients presenting with ILI, 24.66% (924/3,747) had available samples and were enrolled in this study. At least one respiratory virus was identified in 411 patients (44.48%) and 42 (4.55%) were co-infected with two viruses. In patients co-infected with two viruses, respiratory syncytial virus (RSV) was detected in 50% (21/42). Among common viral pathogens detected, significant differences in age distributions were observed in seasonal influenza virus A (sFulA, H3N2) and B (sFluB), pandemic H1N1 2009 influenza viruses (H1N1pdm09), RSV, and adenovirus (ADV). Infections with sFluA (H3N2), sFluB, RSV, and human metapneumovirus (HMPV) had characteristic seasonal patterns. The incidences of sFluA (H3N2), ADV, and RSV correlated with air temperature. Alternatively, the incidence of sFluB correlated with relative air humidity. CONCLUSIONS: These results demonstrate that a wide range of respiratory viral pathogens are circulating in Zhuhai city. This information needs to be considered by clinicians when treating patients presenting with ILI.

[Step Fisher discriminant analysis on severe clinical features of hand foot and mouth disease between enterovirus (EV) 71 and other EV].

OBJECTIVE: To compare the clinical features of severe hand foot and mouth disease between enterovirus (EV) 71 and other EV to find specific diagnosis index of EV71 severe hand foot and mouth disease. METHODS: Case definition were adopted from national guideline of hand foot and mouth disease diagnose (Version 2010). Clinical data of severe hand foot and mouth disease came from case history and contents of questionnaire would include the ones between the time of onset and diagnoses being made. EV and EV71, Cox A16 nucleic acid tested were by RT-PCR in stool samples. Clinical features of severe hand foot and mouth disease between EV71 and other EV were compare. RESULTS: There appeared statistical differences between neurologic symptoms such as tremor, myoclonic jerk, listlessness, convulsion and white blood cell counts in CSF (P < 0.05). Results from the step Fisher discriminant analysis showed only tremor and white blood cell had an increase in CSF, with statistically significant differences. The discriminant equation of EV71 was Y = 3.059X(1) + 3.83X(5) - 2.742 and the equation of other EV was Y = 1.634X(1) + 1.623X(5) - 1.693. The specificity of EV71 was 91% and the specificity of other EV was 40%. CONCLUSION: The increase of clinical features of tremor and white blood cell in CSF could be used as diagnosis index of severe EV71.

[Study on expression of Ras family gene in transformed cells induced by BPDE].

OBJECTIVE: To explore the expression of Ras family gene in the malignantly transformed human bronchial epithelial cell line induced by anti-benzo(a)pyrene-trans-7,8- dihydrodiol-9,10-epoxide(BPDE). METHODS: The levels of H-Ras, K-Ras and N-Ras mRNA expression in BPDE transformed 16HBE cells (16HBE-T) and untransformed control 16HBE cells (16HBE-N) were examined using RT-PCR. Expression levels of those three proteins in both kinds of cells were analyzed by western blot and immunocytochemical method. RESULTS: Compared with 16HBE-N, the levels of H-Ras, K-Ras and N-Ras mRNA expression were significantly increased to 2.237, 1.254 and 3.616 times in 16HBE-T, and the protein levels of those genes were increased to 1.273, 1.547 and 1.600 times, respectively. Immunocytochemical method showed expression levels of those proteins in 16HBE-T were significantly higher than those in 16HBE-N. CONCLUSION: H-Ras, K-Ras and N-Ras are overexpressed in 16HBE-T. The activation of oncogenic Ras may participate in malignant transformation of 16HBE induced by BPDE.

Silencing of N-Ras gene expression using shRNA decreases transformation efficiency and tumor growth in transformed cells induced by anti-BPDE.

Anti-benzo[a]pyrene-trans-7,8-diol-9,10-epoxide (anti-BPDE) is the most important metabolite of benzo[a]pyrene which is a ubiquitous environmental pollutant, and may cause human cancer, especially of the lung. Ras genes (H, K, and N) are activated in 40% of human tumors and may contribute to carcinogenesis. Here, we used malignant human bronchial epithelial cells transformed by anti-BPDE (16HBE-T) to help characterize possible molecular mechanisms of carcinogenesis. We compared H-, K-, and N-Ras mRNA and protein expression levels in 16HBE-T cells and untransformed control 16HBE cells (16HBE-N), using reverse transcription-PCR (RT-PCR) and Western blotting. We further used short hairpin RNA to silence N-Ras gene expression in 16HBE-T cells to determine the effects of silencing on the cell cycle, transformation efficiency and tumor growth. We observed overexpression of H-, K-, and N-Ras genes at both mRNA and protein levels in 16HBE-T cells, compared with 16HBE-N cells. Silencing of N-Ras in 16HBE-T cells using stable RNA interference increased the proportion of cells in G(0)/G(1) phase, decreased the proportion in S-phase, decreased transformation efficiency, and inhibited tumor growth. Our findings suggest that overexpression of N-Ras gene plays an important role in malignant transformation of 16HBE cells by anti-BPDE. N-Ras gene may be a useful target for gene therapy.