Proteome derangement in malignant epithelial cells and its stroma following exposure to 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone.

Discovering novel changes in the proteome of malignant lung epithelial cells and/or the tumor-microenvironment is paramount for diagnostic, prognostic, and/or therapy development. A time-dependent 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)-induced mouse lung tumor model was used to screen the proteome of lung tumors. NNK-transformed human lung epithelial BEAS-2B cells were then established to evaluate the epithelial cell-specific protein changes. A duration-dependent increase of tumor burden was observed in NNK-treated mice, 2/12 (17%), 8/12 (67%), 9/12 (75%), and 10/10 (100%) at weeks 8, 12, 16, and 20 after the NNK exposure, respectively. A total of 25 differentially expressed proteins (≥ twofold change), predominantly structural, signaling, and metabolic proteins, were detected by two-dimensional difference gel electrophoresis and identified by mass spectrometry. Calregulin, ezrin, histamine releasing factor (HRF), and inorganic pyrophosphatase 1 (PPA1) exhibited changes and were further confirmed via immunoblotting. In addition, immunohistochemistry (IHC) analysis indicated upregulated E-cadherin and decreased vimentin expression in epithelial cells of tumor tissues. Acquisition of a neoplastic phenotype in NNK-transformed BEAS-2B cells was demonstrated by enhanced wound closure and increased anchorage independent colony formation. In transformed BEAS-2B cells, protein expression of E-cadherin, ezrin, and PPA1 (but not calregulin and HRF) was upregulated, as was observed in tumor tissues IHC staining using mouse lung tumor tissues further revealed that HRF upregulation was not lung epithelial cell specific. Altogether, tumorigenesis after NNK exposure may be initiated by protein dysregulation in lung epithelial cells together with proteome derangement derived from other cell types existing in the tumor-microenvironment.

Pepsin enhances glycolysis to promote malignant transformation of vocal fold leukoplakia epithelial cells with dysplasia.

PURPOSE: The mechanism underlying malignant transformation of vocal fold leukoplakia (VFL) and the precise role of the expression of pepsin in VFL remain unclear. This study aimed to investigate the effects of acidified pepsin on VFL epithelial cell growth and migration, and also identify pertinent molecular mechanisms. METHODS: Immunochemistry and Western blotting were performed to measure glucose transporter type 1 (GLUT1), monocarboxylate transporters 4 (MCT4), and Hexokinase-II (HK-II) expressions. Cell viability, cell cycle, apoptosis, and migration were investigated by CCK-8 assay, flow cytometry and Transwell chamber assay, respectively. Glycolysis-related contents were determined using the corresponding kits. Mitochondrial HK-II was photographed under a confocal microscope using Mito-Tracker Red. RESULTS: It was found: the expression of pepsin and proportion of pepsin+ cells in VFL increased with the increased dysplasia grade; acidified pepsin enhanced cell growth and migration capabilities of VFL epithelial cells, reduced mitochondrial respiratory chain complex I activity and oxidative phosphorylation, and enhanced aerobic glycolysis and GLUT1 expression in VFL epithelial cells; along with the transfection of GLUT1 overexpression plasmid, 18FFDG uptake, lactate secretion and growth and migration capabilities of VFL epithelial cell were increased; this effect was partially blocked by the glycolysis inhibitor 2-deoxy-glucose; acidified pepsin increased the expression of HK-II and enhanced its distribution in mitochondria of VFL epithelial cells. CONCLUSION: It was concluded that acidified pepsin enhances VFL epithelial cell growth and migration abilities by reducing mitochondrial respiratory complex I activity and promoting metabolic reprogramming from oxidative phosphorylation to aerobic glycolysis.

Biomarkers of exposure and effect in the serum and urine of rats or workers exposed to 1-bromopropane.

Extensively used in several industries in China as a cleaning agent, 1-bromopropane (1-BP) has significant adverse effects on the central nervous system. However, neither its mechanism of action nor sensitive biomarkers related to it have been determined thus far. In this study, animal experiments and occupational surveys were performed to explore the typical exposure and effect biomarkers of neurotoxicity induced by 1-BP. Male Wistar rats were exposed to 0, 500, or 1000 ppm of 1-BP followed by pathological and biomarker analyses. An epidemiological survey was conducted on 71 workers each from 1-BP exposed and control groups. Serum and urine samples were collected for biomarker testing. cNSE represents neuron-specific enolase (NSE) in the cerebral cortex, where as sNSE represents NSE in the serum; similar terminology applies to S-100ß, and cyclooxygenase-2 (COX-2). In rats exposed to 1000 ppm 1-BP, pathological changes were observed in Purkinje cells, lumbar gray matter, and tibiofibular nerve, while levels of cNSE, cS-100ß, cCOX-2, sS-100ß, and sCOX-2 were significantly elevated at different time checkpoints. In the 500 ppm group, cCOX-2, sNSE, and sCOX-2 levels were significantly elevated at different time checkpoints. 1-BP and N-acetyl-S-(n-propyl)-L-cysteine (AcPrCys) were detected in rat urine, and there was a correlation between the level of sNSE or sCOX-2 and AcPrCys in the 500 ppm group. In the occupational epidemiological study, a significant correlation between AcPrCys and exposure concentration was also detected. The findings of this study indicated that AcPrCys was a sensitive exposure biomarker of 1-BP in rats as well as occupational populations.

Helicobacter pylori Immunoproteomic Profiles in Gastric Cancer.

Chronic Helicobacter pylori infection is the major risk factor for gastric cancer (GC). However, only some infected individuals develop this neoplasia. Previous H. pylori serology studies have been limited by investigating small numbers of candidate antigens. Therefore, we evaluated humoral responses to a nearly complete H. pylori immunoproteome (1527 proteins) among 50 GC cases and 50 controls using Nucleic Acid Programmable Protein Array (NAPPA). Seropositivity was defined as median normalized intensity ≥2 on NAPPA, and 53 anti-H. pylori antibodies had >10% seroprevalence. Anti-GroEL exhibited the greatest seroprevalence (77% overall), which agreed well with ELISA using whole-cell lysates of H. pylori cells. After an initial screen by H. pylori-NAPPA, we discovered and verified that 12 antibodies by ELISA in controls had ≥15% of samples with an optical reading value exceeding the 95th percentile of the GC group. ELISA-verified antibodies were validated blindly in an independent set of 100 case-control pairs. As expected, anti-CagA seropositivity was positively associated with GC (odds ratio, OR = 5.5; p < 0.05). After validation, six anti-H. pylori antibodies showed lower seropositivity in GC, with ORs ranging from 0.44 to 0.12 (p < 0.05): anti-HP1118/Ggt, anti-HP0516/HsIU, anti-HP0243/NapA, anti-HP1293/RpoA, anti-HP0371/FabE, and anti-HP0875/KatA. Among all combinations, a model with anti-Ggt, anti-HslU, anti-NapA, and anti-CagA had an area under the curve of 0.73 for discriminating GC vs. controls. This study represents the first comprehensive assessment of anti-H. pylori humoral profiles in GC. Decreased responses to multiple proteins in GC may reflect mucosal damage and decreased bacterial burden. The higher prevalence of specific anti-H. pylori antibodies in controls may suggest immune protection against GC development.

Identification of anti-Epstein-Barr virus (EBV) antibody signature in EBV-associated gastric carcinoma.

BACKGROUND: Around 10% of gastric carcinomas (GC) contain Epstein-Barr virus (EBV) DNA. We characterized the GC-specific antibody response to this common infection, which may provide a noninvasive method to detect EBV-positive GC and elucidate its contribution to carcinogenesis. METHODS: Plasma samples from EBV-positive (n = 28) and EBV-negative (n = 34) Latvian GC patients were immune-profiled against 85 EBV proteins on a multi-microbial Nucleic Acid Programmable Protein Array (EBV-NAPPA). Antibody responses were normalized for each sample as ratios to the median signal intensity (MNI) across all antigens, with seropositivity defined as MNI ≥ 2. Antibodies with ≥ 20% sensitivity at 95% specificity for tumor EBV status were verified by enzyme-linked immunosorbent assay (ELISA) and validated in independent samples from Korea and Poland (n = 24 EBV-positive, n = 65 EBV-negative). RESULTS: Forty anti-EBV IgG and eight IgA antibodies were detected by EBV-NAPPA in ≥ 10% of EBV-positive or EBV-negative GC patients, of which nine IgG antibodies were discriminative for tumor EBV status. Eight of these nine were verified and seven were validated by ELISA: anti-LF2 (odds ratio = 110.0), anti-BORF2 (54.2), anti-BALF2 (44.1), anti-BaRF1 (26.7), anti-BXLF1 (12.8), anti-BRLF1 (8.3), and anti-BLLF3 (5.4). The top three had areas under receiver operating characteristics curves of 0.81-0.85 for distinguishing tumor EBV status. CONCLUSIONS: The EBV-associated GC-specific humoral response was exclusively directed against lytic cycle immediate-early and early antigens, unlike other EBV-associated malignancies such as nasopharyngeal carcinoma and lymphoma where humoral response is primarily directed against late lytic antigens. Specific anti-EBV antibodies could have utility for clinical diagnosis, epidemiologic studies, and immune-based precision treatment of EBV-positive GC.

Overcoming the acquired resistance to gefitinib in lung cancer brain metastasis in vitro and in vivo.

In our previous work, PC-9-Br, a PC-9 brain seeking line established via a preclinical animal model of lung cancer brain metastasis (LCBM), exhibited not only resistance to epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) gefitinib in vitro, but also chemotherapy regimens of cisplatin plus etoposide in vivo. Using this cell line, we investigated novel potential targeted therapeutics for treating LCBM in vitro and in vivo to combat drug resistance. Significant increases in mRNA and protein expression levels of Bcl-2 were found in PC-9-Br compared with parental PC-9 (PC-9-P), but no significant changes of Bcl-XL were observed. A remarkable synergistic effect between EGFR-TKI gefitinib and Bcl-2 inhibitors ABT-263 (0.17 ± 0.010 µM at 48 h and 0.02 ± 0.004 µM at 72 h), or ABT-199 (0.22 ± 0.008 µM at 48 h and 0.02 ± 0.001 µM at 72 h) to overcome acquired resistance to gefitinib (> 0.5 µM at 48 h and 0.10 ± 0.007 µM at 72 h) in PC-9-Br was observed in MTT assays. AZD9291 was also shown to overcome acquired resistance to gefitinib in PC-9-Br in MTT assays (0.23 ± 0.031 µM at 48 h and 0.03 ± 0.008 µM at 72 h). Western blot showed significantly decreased phospho-Erk1/2 and increased cleaved-caspase-3 expressions were potential synergistic mechanisms for gefitinib + ABT263/ABT199 in PC-9-Br. Significantly decreased protein expressions of phospho-EGFR, phospho-Akt, p21, and survivin were specific synergistic mechanism for gefitinib + ABT199 in PC-9-Br. In vivo studies demonstrated afatinib (30 mg/kg) and AZD9291 (25 mg/kg) could significantly reduce the LCBM in vivo and increase survival percentages of treated mice compared with mice treated with vehicle and gefitinib (6.25 mg/kg). In conclusion, our study demonstrated gefitinib + ABT263/ABT199, afatinib, and AZD9291 have clinical potential to treat LCBM.

Chronic electronic cigarette use elicits molecular changes related to pulmonary pathogenesis.

The relative safety of chronic exposure to electronic cigarette (e-cig) aerosol remains unclear in terms of lung pathogenesis. Therefore, this study aims to evaluate gene/protein biomarkers, which are associated with cigarette-induced pulmonary injury in animals chronically exposed to nicotine containing e-cig aerosol. C57BL/6 J mice were randomly assigned to three exposure groups: e-cig, tobacco cigarette smoke, and filtered air. Lung tissues and/or paraffin embedded slides were used to evaluate gene and/or protein expressions of the CYP450 metabolism (CYP1A1, CYP2A5, and CYP3A11), oxidative stress (Nrf2, SOD1), epithelial-mesenchymal transition (E-cadherin and vimentin), lung pathogenesis (AhR), and survival/apoptotic pathways (p-AKT, BCL-XL, p53, p21, and CRM1). Expressions of E-cadherin and CRM1 were significantly decreased, while CYP1A1, AhR, SOD1 and BCL-XL were significantly upregulated in the e-cig group compared to the control (p < 0.05). Nuclear sub-cellular localization of p53, evaluated by immunohistochemistry staining, in bronchiolar tissues was higher in the e-cig group (25.3 ± 2.7%) as compared to controls (12.1 ± 1.8%) (p < 0.01). Although the biomarkers responses were not identical, in general, the responses had similar qualitative trends between the e-cig and cigarette groups. As these related molecular changes are involved in the pathogenesis of cigarette-induced lung injury, the possibility exists that e-cigs can produce a similar outcome. Although further investigation is warranted, e-cigs are unlikely to be considered as safe in terms of pulmonary health.

Drug resistance occurred in a newly characterized preclinical model of lung cancer brain metastasis.

BACKGROUND: Cancer metastasis and drug resistance have traditionally been studied separately, though these two lethal pathological phenomena almost always occur concurrently. Brain metastasis occurs in a large proportion of lung cancer patients (~ 30%). Once diagnosed, patients have a poor prognosis surviving typically less than 1 year due to lack of treatment efficacy. METHODS: Human metastatic lung cancer cells (PC-9-Br) were injected into the left cardiac ventricle of female athymic nude mice. Brain lesions were allowed to grow for 21 days, animals were then randomized into treatment groups and treated until presentation of neurological symptoms or when moribund. Prior to tissue collection mice were injected with Oregon Green and 14C-Aminoisobutyric acid followed by an indocyanine green vascular washout. Tracer accumulation was determined by quantitative fluorescent microscopy and quantitative autoradiography. Survival was tracked and tumor burden was monitored via bioluminescent imaging. Extent of mutation differences and acquired resistance was measured in-vitro through half-maximal inhibitory assays and qRT-PCR analysis. RESULTS: A PC-9 brain seeking line (PC-9-Br) was established. Mice inoculated with PC-9-Br resulted in a decreased survival time compared with mice inoculated with parental PC-9. Non-targeted chemotherapy with cisplatin and etoposide (51.5 days) significantly prolonged survival of PC-9-Br brain metastases in mice compared to vehicle control (42 days) or cisplatin and pemetrexed (45 days). Further in-vivo imaging showed greater tumor vasculature in mice treated with cisplatin and etoposide compared to non-tumor regions, which was not observed in mice treated with vehicle or cisplatin and pemetrexed. More importantly, PC-9-Br showed significant resistance to gefitinib by in-vitro MTT assays (IC50 > 2.5 µM at 48 h and 0.1 µM at 72 h) compared with parental PC-9 (IC50: 0.75 µM at 48 h and 0.027 µM at 72 h). Further studies on the molecular mechanisms of gefitinib resistance revealed that EGFR and phospho-EGFR were significantly decreased in PC-9-Br compared with PC-9. Expression of E-cadherin and vimentin did not show EMT in PC-9-Br compared with parental PC-9, and PC-9-Br had neither a T790M mutation nor amplifications of MET and HER2 compared with parental PC-9. CONCLUSION: Our study demonstrated that brain metastases of lung cancer cells may independently prompt drug resistance without drug treatment.

Effect of short-term vitamin D supplementation after nonsurgical periodontal treatment: A randomized, double-masked, placebo-controlled clinical trial.

OBJECTIVES: This trial aimed to evaluate the efficacy and safety of vitamin D supplementation on the residual moderate and deep pockets following nonsurgical periodontal therapy. BACKGROUND: Vitamin D supplementation has potential effects on periodontitis, but current evidence remains inconclusive. METHODS: After 3 months of nonsurgical periodontal treatment, 360 patients with moderate or severe periodontitis were randomly assigned to 2000 international unit (IU)/d vitamin D3, 1000 IU/d vitamin D3, or placebo. Clinical periodontal examinations, including probing depth (PD), bleeding index (BI), plaque index (PLI), attachment loss (AL), and alveolar crest height (ACH), were performed at baseline and after 3 months of intervention. RESULTS: There was a slight but significant decrease in AL and PD in both vitamin D groups compared with placebo group for moderate and deep pockets. About 2000 IU/d vitamin D3 group, 1000 IU/d vitamin D3 group, and placebo group all decreased the AL for both moderate pockets (-0.4 mm vs -0.4 mm vs -0.3 mm) and deep pockets (-1.1 mm vs -1.1 mm vs -1.0 mm) (all P < .05). Similarly, PD was also decreased in these three groups for both moderate pockets and deep pockets (all P < .05). In addition, vitamin D supplementation was well tolerated, and no adverse events were reported. CONCLUSIONS: Although statistically significant differences were observed in favor to vitamin D supplementation, the magnitude of effect size tended to be modest with limited clinical relevance and the long-term efficacy and safety warrant further investigation.

Synergistic effects of Bcl-2 inhibitors with AZD9291 on overcoming the acquired resistance of AZD9291 in H1975 cells.

Non-small cell lung cancer (NSCLC) patients with epithermal growth factor receptor (EGFR) mutations can be treated with EGFR-tyrosine kinase inhibitors (EGFR-TKIs), however, development of acquired resistance could significantly limit curative effects of EGFR-TKIs. Different mechanisms of acquired resistance to first-generation and second-generation EGFR TKIs have been widely reported, but there were few reports on the resistant mechanism of third-generation EGFR-TKI such as osimertinib (AZD9291). In the present study, significant upregulation of Bcl-2 was found in AZD9291-resistant H1975 cells (H1975AR) compared with H1975, which may constitute an important resistant mechanism of acquired resistance to AZD9291. More importantly, our study showed that synergism between AZD9291 and Bcl-2 inhibitor ABT263 (0.25 µM) or ABT199 (1 µM) could effectively overcome the acquired resistance of AZD9291 in H1975AR in vitro. Flow cytometry analyses demonstrated that AZD9291 + ABT263/ABT199 caused a significantly different cell cycle distribution and produced significantly more apoptosis compared with either AZD9291 or ABT263/ABT199 treatment alone. Further multiscreen/Western blot analyses revealed that NF-κB was significantly downregulated in AZD9291 + ABT263/ABT199 treatment groups compared with AZD9291 or ABT263/ABT199 treatment alone, with a more significant reduction of NF-κB in AZD9291 + ABT199 compared with AZD9291 + ABT263. It is also noticeable that AZD9291 + ABT263 specifically caused a significantly reduced expression of p21 compared with AZD9291 or ABT263 treatment alone while AZD9291 + ABT199 specifically caused significantly reduced expressions of SQSTM1 and survivin, but increased expression of autophagosome marker LC3-II compared with AZD9291 or ABT199 treatment alone. Furthermore, cytotoxicity of AZD9291 + ABT199 could be partially reversed by autophagy inhibitor chloroquine. These results suggest that ABT263 and ABT199 may work through different signaling pathways to achieve synergistic cytotoxicity with AZD9291 in H1975AR. These findings suggest that Bcl-2 inhibitor may provide an effective option in combination therapy with EGFR-TKIs to treat NSCLC with EGFR-TKI acquired resistance.

Overcoming acquired resistance of gefitinib in lung cancer cells without T790M by AZD9291 or Twist1 knockdown in vitro and in vivo.

The T790M mutation is recognized as a typical mechanism of acquired resistance to first generation of epithermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) such as gefitinib in non-small cell lung cancer (NSCLC) patients who are commonly treated by third generation of EGFR-TKI AZD9291 (osimertinib). However, the therapeutic strategy for overcoming acquired resistance to EGFR-TKIs in NSCLC patients without T790M remains to be definitively determined. In the present study, gefitinib-resistant H1650 (H1650GR) or AZD9291-resistant H1975 (H1975AR) was generated by exposing NSCLC cell line H1650 or H1975 to progressively increased concentrations of gefitinib or AZD9291 over 11 months. The cytotoxic effects of gefitinib or AZD9291 in vitro were evaluated via the half maximal inhibitory concentrations (IC50s) determined by the MTT assay. IC50 of gefitinib in H1650GR (50.0 ± 3.0 µM) significantly increased compared with H1650 (31.0 ± 1.0 µM) (p < 0.05). Similarly, the IC50 of AZD9291 in H1975AR (10.3 ± 0.9 µM) significantly increased compared with H1975 (5.5 ± 0.6 µM) (p < 0.05). However, IC50 of AZD9291 on H1650GR (8.5 ± 0.5 µM) did not increase compared with H1650 (9.7 ± 0.7 µM). On the other hand, IC50 of AZD9291 on gefitinib-resistant A549 (A549GR established in our previous study) (12.7 ± 0.8 µM) was significantly increased compared with A549 (7.0 ± 1.0 µM) (p < 0.05). AZD9291 induced caspase 3/7 activation in A549, H1650, and H1650GR, but not in A549GR. Western blot analyses showed that p-Akt played a key role in determining the sensitivities of A549, A549GR, H1650, and H1650GR to gefitinib or AZD9291. Additionally, increased expression of Twist1 was observed in all cells with acquired EGFR-TKI resistance and knockdown of Twist1 by shRNA was found to significantly enhance the sensitivity of A549GR to gefitinib or AZD9291 via reversing epithelial-mesenchymal transition and downregulating p-Akt, but not of H1975AR to AZD9291. The enhanced cytotoxic effect of AZD9291 on A549GR by Twist1 knockdown in vitro was further validated by in vivo studies which showed that Twist1 knockdown could lead to significantly delayed tumor growth of A549GR xenograft with increased sensitivity to AZD9291 treatment in nude mice without any observed side toxic effects. In summary, our study demonstrated that the mechanisms of acquired resistance in different NSCLC cell lines treated by even the same EGFR-TKI might be quite different, which provide a rationale for adopting different therapeutic strategies for those NSCLC patients with acquired EGFR-TKI resistance based on different status of heterogeneous mutations.

Improved Performance of Loop-Mediated Isothermal Amplification Assays via Swarm Priming.

This work describes an enhancement to the loop-mediated isothermal amplification (LAMP) reaction which results in improved performance. Enhancement is achieved by adding a new set of primers to conventional LAMP reactions. These primers are termed "swarm primers" based on their relatively high concentration and their ability to create new amplicons despite the theoretical lack of single-stranded annealing sites. The primers target a region upstream of the FIP/BIP primer recognition sequences on opposite strands, substantially overlapping F1/B1 sites. Thus, despite the addition of a new primer set to an already complex assay, no significant increase in assay complexity is incurred. Swarm priming is presented for three DNA templates: Lambda phage, Synechocystis sp. PCC 6803 rbcL gene, and human HFE. The results of adding swarm primers to conventional LAMP reactions include increased amplification speed, increased indicator contrast, and increased reaction products. For at least one template, minor improvements in assay repeatability are also shown. In addition, swarm priming is shown to be effective at increasing the reaction speed for RNA amplification via RT-LAMP. Collectively, these results suggest that the addition of swarm primers will likely benefit most if not all existing LAMP assays based on state-of-the-art, six-primer reactions.

Sequence-dependent cleavage of mismatched DNA by Ban I restriction endonuclease.

Restriction enzymes have previously shown the ability to cleave DNA substrates with mismatched base(s) in recognition sequences; in this study, Ban I endonuclease demonstrated this same ability. Single base substitutions were introduced, and fragments containing various types of unpaired base(s) (heteroduplex fragments) within the Ban I endonuclease recognition sequence, 5'-G|GPyPuCC-3', were generated. Each of the heteroduplex fragments was treated with Ban I endonuclease and analyzed by denaturing gradient gel electrophoresis. Our results showed that heteroduplex fragments containing mismatched bases at either the first or third position of the Ban I recognition sequence or, because of the symmetrical structure of the sequence, the sixth or fourth position on the opposite strand were cleaved by the enzyme. Furthermore, these cleaved fragments contained at least one strand corresponding to the original Ban I recognition sequence. Fragments with mismatches formed by an A (noncanonical, nc) opposite a purine (canonical, ca) or a T (nc) opposite a pyrimidine (ca) were cleaved more efficiently than other types of mismatched bases. These results may help elucidate the mechanisms by which DNA and protein interact during the process of DNA cleavage by Ban I endonuclease.

KRAS and TP53 mutations in bronchoscopy samples from former lung cancer patients.

Mutations in the KRAS and TP53 genes have been found frequently in lung tumors and specimens from individuals at high risk for lung cancer and have been suggested as predictive markers for lung cancer. In order to assess the prognostic value of these two genes' mutations in lung cancer recurrence, we analyzed mutations in codon 12 of the KRAS gene and in hotspot codons of the TP53 gene in 176 bronchial biopsies obtained from 77 former lung cancer patients. Forty-seven patients (61.0%) showed mutations, including 35/77 (45.5%) in the KRAS gene and 25/77 (32.5%) in the TP53 gene, among them 13/77 (16.9%) had mutations in both genes. When grouped according to past or current smoking status, a higher proportion of current smokers showed mutations, in particular those in the TP53 gene (P = 0.07), compared with ex-smokers. These mutations were found in both abnormal lesions (8/20 or 40%) and histologically normal tissues (70/156 or 44.9%) (P = 0.812). They consisted primarily of G to A transition and G to T transversion in both the KRAS (41/56 or 73.2%) and TP53 (24/34 or 70.6%) genes, consistent with mutations found in lung tumors of smoking lung cancer patients. Overall, recurrence-free survival (RFS) among all subjects could be explained by age at diagnosis, tumor stage, tumor subtype, and smoking (P < 0.05, Cox proportional hazard). Therefore, KRAS and TP53 mutations were frequently detected in bronchial tissues of former lung cancer patients. However, the presence of mutation of bronchial biopsies was not significantly associated with a shorter RFS time. © 2016 Wiley Periodicals, Inc.

Leptomycin B reduces primary and acquired resistance of gefitinib in lung cancer cells.

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) gefitinib has demonstrated dramatic clinical efficacy in non-small cell lung cancer (NSCLC) patients. However, its therapeutic efficacy is ultimately limited by the development of acquired drug resistance. The aim of this study was to explore the potential utility of chromosome region maintenance 1 (CRM1) inhibitor leptomycin B (LMB) in combination with gefitinib to overcome primary and acquired gefitinib resistance in NSCLC cells. The combinative effects of gefitinib and LMB were evaluated by MTT and its underlining mechanism was assessed by flow cytometry and Western blot. LMB displayed a synergistic effect on gefitinib-induced cytotoxicity in A549 (IC50: 25.0±2.1µM of gefitinib+LMB vs. 32.0±2.5µM of gefitinib alone, p<0.05). Gefitinib+LMB caused a significantly different cell cycle distribution and signaling pathways involved in EGFR/survivin/p21 compared with gefitinib. A549 cells then were treated with progressively increased concentrations of gefitinib (A549GR) or in combination with LMB (A549GLR) over 10months to generate gefitinib resistance. IC50 of gefitinib in A549GLR (37.0±2.8µM) was significantly lower than that in A549GR (53.0±3.0µM, p<0.05), which indicates that LMB could reverse gefitinib-induced resistance in A549. Further mechanism investigation revealed that the expression patterns of EGFR pathway and epithelial-mesenchymal transition (EMT) markers in A549, A549GR, and A549GLR were significantly different. In conclusion, LMB at a very low concentration (0.5nM) combined with gefitinib showed synergistic therapeutic effects and ameliorated the development of gefitinib-induced resistance in lung cancer cells.

Long-term exposure to diesel engine exhaust induces primary DNA damage: a population-based study.

OBJECTIVES: Diesel engine exhaust (DEE) is a ubiquitous environmental pollutant and is carcinogenic to humans. To seek early and sensitive biomarkers for prediction of adverse health effects, we analysed the components of DEE particles, and examined the genetic and oxidative damages in DEE-exposed workers. METHODS: 101 male diesel engine testing workers who were constantly exposed to DEE and 106 matched controls were enrolled in the present study. The components of DEE were analysed, including fine particulate matter (PM2.5), element carbon (EC), nitrogen dioxide (NO2), sulfur dioxide (SO2) and polycyclic aromatic hydrocarbons (PAHs). Postshift urine samples were collected and analysed for 1-hydroxypyrene (1-OHP), an internal exposure marker for DEE. Levels of DNA strand breaks and oxidised purines, defined as formamidopyrimidine-DNA glycosylase (FPG) sites in leucocytes, were measured by medium throughput Comet assay. Urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) was also used to determine the level of oxidative stress. RESULTS: We found higher levels of PM2.5, EC, NO2, SO2 and PAHs in the diesel engine testing workshop and significantly higher urinary 1-OHP concentrations in exposed subjects (p<0.001). Compared with controls, the levels of parameters in normal Comet and FPG-Comet assay were all significantly higher in DEE-exposed workers (p<0.001), and in a dose-dependent and time-dependent manner. There were no significant differences between DEE-exposed workers and controls in regard to leucocyte FPG sensitive sites and urinary 8-OHdG levels. CONCLUSIONS: These findings suggest that DEE exposure mainly induces DNA damage, which might be used as an early biomarker for risk assessment of DEE exposure.

Associations between DNA methylation in DNA damage response-related genes and cytokinesis-block micronucleus cytome index in diesel engine exhaust-exposed workers.

Recently, diesel engine exhaust (DEE) was reclassified as a known carcinogen to humans. DNA methylation alterations in DNA damage response (DDR)-related genes have the potential to affect DEE exposure-related cancer risk. However, the evidence regarding the association between DEE exposure and methylation alterations in DDR-related genes is limited. In 117 DEE-exposed workers and 112 non-DEE-exposed workers, we measured urinary concentrations of six mono-hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs). We also determined the methylation levels of three DDR-related genes (p16, RASSF1A, and MGMT) and LINE-1 by bisulfite-pyrosequencing assay. We found that DEE-exposed workers exhibited significantly lower mean promoter methylation levels of p16, RASSF1A, and MGMT than non-DEE-exposed workers (all p < 0.001). In all study subjects and non-smoking workers, increasing quartiles of urinary summed OH-PAHs was associated with hypomethylation of p16, RASSF1A, and MGMT (all p < 0.05). In non-smoking workers, methylation in p16, RASSF1A, and MGMT decreased by 0.36 % [95 % confidential interval (CI): -0.60, -0.11 %], 0.46 % (95 % CI: -0.79, -0.14 %), and 0.55 % (95 % CI: -0.95, -0.15 %), respectively, in association with highest versus lowest quartile of urinary summed OH-PAHs. In addition, p16, RASSF1A, MGMT, and LINE-1 methylation levels showed negative correlations with cytokinesis-block micronucleus cytome index which was previously measured in the same workers (all p < 0.05). In conclusion, our results clearly indicated that DEE exposure and increased genetic damage were associated with hypomethylation of p16, RASSF1A, and MGMT. Future studies with larger sample size are needed to confirm these associations.

miR-138-1* regulates aflatoxin B1-induced malignant transformation of BEAS-2B cells by targeting PDK1.

Environmental carcinogens-induced lung cancer and potential mechanisms have attracted widespread attention. Currently, microRNAs (miRNAs) have been recognized as key players in development of cancer, among which guide strand of miRNA has been well documented rather than its passenger strand (miRNA*). Our previous study showed that treatment of 0.1 nM AFB1 for 50 passages could induce malignant transformation of immortalized human bronchial epithelial cells stably expressing CYP2A13 (P50 B-2A13 cells). However, the role of miRNAs in this carcinogenic proceeding is still unclear. In present study, 36 upregulated and 27 downregulated miRNAs in P50 B-2A13 cells were first identified by miRNA microarray, and miR-138-1* was selected as a candidate miRNA by RT-qPCR and pilot experiments. Functional studies revealed that miR-138-1* could inhibit proliferation, colony formation, migration and invasion of P50 B-2A13 cells. Further, target analysis and dual-luciferase reporter gene assay identified that miR-138-1(*) was consequentially paired with 3'-UTR of 3-phosphoinositide-dependent protein kinase-1 (PDK1) and decreased the luciferase activity. miR-138-1* could decrease the expressions of PDK1 and its downstream proteins in PI3K/PDK/Akt pathway but not vice versa, indicating that miR-138-1* might affect AFB1-induced malignant transformation through targeting PDK1. As predicted, interference of PDK1 showed the similar effects to miR-138-1* in the proliferation, colony formation, migration and invasion of P50 B-2A13 cells. Our study demonstrated that miR-138-1* played a critical role in AFB-induced malignant transformation of B-2A13 cells by targeting PDK1. Still, the study provides a novel insight into the roles of miRNA* during carcinogenesis, particularly airborne carcinogens-induced lung cancer.

Cytotoxicity of diesel engine exhaust among the Chinese occupational population: a complement of cytokinesis-block micronucleus cytome.

Diesel engine exhaust (DEE), a ubiquitous environmental pollutant, has been associated with adverse health effects. Revelation of cellular and molecular changes is critical for understanding environmental exposure-related diseases. Although the molecular-level effects of DEE exposure have been investigated, whether it is associated with aberrant changes at cellular level is largely unknown at the population level. In the present study, we measured urinary concentrations of 6 mono-hydroxylated PAHs (OH-PAHs) and cytotoxicity-related endpoints including apoptosis and necrosis frequencies, and nuclear division cytotoxicity index (NDCI) in peripheral blood lymphocytes (PBLs) of 79 DEE-exposed workers and 59 non-DEE-exposed workers. We found that DEE-exposed workers had significantly higher necrosis frequency and lower NDCI than did non-DEE-exposed workers (both p < 0.001). In all study subjects and nonsmoking workers, urinary summed OH-PAHs was associated with increased necrosis frequency and reduced NDCI. In nonsmoking workers, an interquartile range increase in urinary summed OH-PAHs was associated with 105.03% increase in necrosis frequency and 8.70% decrease in NDCI. Taking advantage of the previous measure of micronucleus frequency, we observed that micronucleus frequency was positively correlated with apoptosis and necrosis frequencies (r = 0.277, p = 0.047 and r = 0.452, p = 0.001, respectively) and negatively correlated with NDCI (r = -0.477, p < 0.001). In conclusion, our results suggested that DEE exposure was associated with increased necrosis frequency and further with reduced NDCI in PBLs, providing evidence of DEE exposure-induced cytotoxicity in humans.

[Safety and Tolerance of Healthy People to Injection of Astragalosides-a New Drug for Coronary Heart Disease].

OBJECTIVES: To assess the safety and tolerance of healthy volunteers to as tragalosides injection (AGI), and to determine a safe dose range for phase II clinical trial. METHODS: A total of 62 healthy volunteers participated in this study, with 26 being given a single AGI of 100 mL, 200 mL, 300 mL, 400 mL, 500 mL, or 600 mL and 36 subjects being given 500 mL, 400 mL, 200 mL or 300 mL of AGI once a day for 7 d. Discomfortsymptoms, vital signs and safety problems were recorded 3 d and 7 d after the administration of AGI. The results were analyzed. RESULTS: Of the 62 participants, 40 adverse events (AEs) were reported by 31 participants, which included 23 mild adverse reactions (ADRs) and 4 moderate ADRs. Nine AEs were reported by 9 participants with single AGI, including 7 ADRs. Fourteen AEs were reported by 10 participants with 500 mL and 400 mL multiple AGI, including 12 ADRs occurred in 9 participants.Seventeen AEs were reported by 12 participants with 300 mL and 300 mL multiple AGI, including 3 mild ADRs. The main ADRs included abnormal liver function [slightly elevated glutamic pyruvic transaminase (ALT), glutamic oxaloacetic transaminase (AST),and serum total bilirubin (TBil)], low blood potassium, increased urine red blood cell count, rash, and phlebitis. CONCLUSIONS: The maximum tolerance is 600 mL for single-dose treatment, and 400 mL for multiple-dose (7 d). The dose guidance given in this study should be examined its effects and safety in patients with coronary heart disease in phase II clinical trial.