• 3-aminobenzanthrone, a human metabolite of the carcinogenic environmental pollutant 3-nitrobenzanthrone, induces biotransformation enzymes in rat kidney and lung.

      Stiborova, Marie; Dracinska, Helena; Martinkova, Marketa; Mizerovska, Jana; Hudecek, Jiri; Hodek, Petr; Liberda, Jiri; Frei, Eva; Schmeiser, Heinz H.; Phillips, David H.; et al. (2009-05-31)
      3-aminobenzanthrone (3-ABA) is the metabolite of the carcinogenic air pollutant 3-nitrobenzanthrone (3-NBA). 3-ABA was investigated for its ability to induce cytochrome P450 1A1 (CYP1A1) and NAD(P)H:quinone oxidoreductase (NQO1) in kidney and lung of rats, and for the influence of such induction on DNA adduct formation by 3-ABA and 3-NBA. NQO1 is the enzyme that reduces 3-NBA to N-hydroxy-3-aminobenzanthrone (N-OH-3-ABA) and CYP1A enzymes oxidize 3-ABA to the same intermediate. When activated by cytosolic and and/or microsomal fractions isolated from rat lung, the target organ for 3-NBA carcinogenicity, and kidney, both compounds generated the same DNA-adduct pattern, consisting of five adducts. When pulmonary cytosols isolated from rats that had been treated i.p. with 40 mg/kg bw of 3-ABA were incubated with 3-NBA, DNA adduct formation was up to 1.7-fold higher than in incubations with cytosols from control animals. This increase corresponded to an increase in protein level and enzymatic activity of NQO1. In contrast, no induction of NQO1 expression by 3-ABA treatment was found in the kidney. Incubations of 3-ABA with renal and pulmonary microsomes of 3-ABA-treated rats led to an increase of up to a 4.5-fold in DNA-adduct formation relative to controls. The stimulation of DNA-adduct formation correlated with a higher protein expression and activity of CYP1A1 induced by 3-ABA. These results show that by inducing lung and kidney CYP1A1 and NQO1, 3-ABA increases its own enzymatic activation as well as that of the environmental pollutant, 3-NBA, thereby enhancing the genotoxic and carcinogenic potential of both compounds.
    • 3-Nitrobenzanthrone and 3-aminobenzanthrone induce DNA damage and cell signalling in Hepa1c1c7 cells.

      Landvik, N.E.; Arlt, V.M.; Nagy, E.; Solhaug, A.; Tekpli, X.; Schmeiser, H.H.; Refsnes, M.; Phillips, D.H.; Lagadic-Gossmann, D.; Holme, J.A. (2010-02-03)
      3-Nitrobenzanthrone (3-NBA) is a mutagenic and carcinogenic environmental pollutant found in diesel exhaust and urban air pollution. In the present work we have characterised the effects of 3-NBA and its metabolite 3-aminobenzanthrone (3-ABA) on cell death and cytokine release in mouse hepatoma Hepa1c1c7 cells. These effects were related to induced DNA damage and changes in cell signalling pathways. 3-NBA resulted in cell death and caused most DNA damage as judged by the amount of DNA adducts ((32)P-postlabelling assay), single strand (ss)DNA breaks and oxidative DNA lesions (comet assay) detected. An increased phosphorylation of H2AX, chk1, chk2 and partly ATM was observed using flow cytometry and/or Western blotting. Both compounds increased phosphorylation of p53 and MAPKs (ERK, p38 and JNK). However, only 3-NBA caused an accumulation of p53 in the nucleus and a translocation of Bax to the mitochondria. The p53 inhibitor pifithrin-alpha inhibited 3-NBA-induced apoptosis, indicating that cell death was a result of the triggering of DNA signalling pathways. The highest phosphorylation of Akt and degradation of IkappaB-alpha (suggesting activation of NF-kappaB) were also seen after treatment with 3-NBA. In contrast 3-ABA increased IL-6 release, but caused little or no toxicity. Cytokine release was inhibited by PD98059 and curcumin, suggesting that ERK and NF-kappaB play a role in this process. In conclusion, 3-NBA seems to have a higher potency to induce DNA damage compatible with its cytotoxic effects, while 3-ABA seems to have a greater effect on the immune system.
    • 8-Oxo-7,8-dihydroguanine and uric acid as efficient predictors of survival in colon cancer patients.

      Dziaman, Tomasz; Banaszkiewicz, Zbigniew; Roszkowski, Krzysztof; Gackowski, Daniel; Wisniewska, Ewa; Rozalski, Rafał; Foksinski, Marek; Siomek, Agnieszka; Speina, Elzbieta; Winczura, Alicja; et al. (2013-07-05)
      The aim of this work was to answer the question whether the broad range of parameters which describe oxidative stress and oxidatively damaged DNA and repair are appropriate prognosis factors of colon cancer (CRC) patients survival? The following parameters were analyzed for 89 CRC patients: concentration of uric acid and vitamins A, E, C in plasma; levels of 8-oxodGuo (8-oxo-7,8-dihydro-2'-deoxyguanosine) in DNA of leukocyte and colon tissues; urinary excretion rates of 8-oxodGuo and 8-oxoGua (8-oxo-7,8-dihydroguanine); the activity and mRNA or protein level of repair enzymes OGG1, APE1, ANPG, TDG and PARP1. All DNA modifications and plasma antioxidants were analyzed using high performance liquid chromatography (HPLC) or HPLC/gas chromatography-mass spectrometry techniques. Expression of repair proteins was analyzed by QPCR, Western or immunohistochemistry methods. Longer survival coincided with low levels of 8-oxodGuo/8oxoGua in urine and 8-oxodGuo in DNA as well as with high concentration of uric acid plasma level. In contrast to expectations, longer survival coincided with lower mRNA level in normal colon tissue of the main 8-oxoGua DNA glycosylase, OGG1, but no association was found for PARP-1 expression. When analyzing simultaneously two parameters the discriminating power increased significantly. Combination of low level of urinary 8-oxoGua together with low level of 8-oxodGuo in leukocyte (both below median value) or high concentration of plasma uric acid (above median value) have the best prediction power. Since prediction value of these parameters seems to be comparable to conventional staging procedure, they could possibly be used as markers to predict clinical success in CRC treatment.
    • 8-Oxoguanine DNA-glycosylase repair activity and expression: a comparison between cryopreserved isolated lymphocytes and EBV-derived lymphoblastoid cell lines.

      Mazzei, Filomena; Guarrera, Simonetta; Allione, Alessandra; Simonelli, Valeria; Narciso, Laura; Barone, Flavia; Minoprio, Anna; Ricceri, Fulvio; Funaro, Ada; D'Errico, Mariarosaria; et al. (2011-01-10)
      Several lines of evidence suggest an association between oxidative DNA-damage repair capacity and cancer risk. In particular, a DNA-glycosylase assay for removal of 8-oxoguanine (8-oxoG) in peripheral blood mononuclear cells (PBMC) has been successfully applied to identify populations with increased risk for lung cancer and squamous cell carcinomas of head and neck. In order to verify whether EBV-transformed lymphoblastoid cell lines (LCL) are a suitable surrogate for PBMC in specific DNA-repair phenotypic assays, a validation trial was conducted. PBMC from 20 healthy subjects were collected and an aliquot was transformed with EBV to obtain LCL. The ability of cell-free extracts from both cell types to incise a 3'-fluorescently labelled duplex oligonucleotide containing a single 8-oxoG (OGG assay) was evaluated. Since this activity is mediated predominantly by OGG1, the OGG1 gene expression was also measured. 8-oxoG DNA-glycosylase activity and OGG1 expression were significantly higher (p<0.0001) in LCL than in PBMC. However, while this assay was shown to be robust and reproducible when used on PBMC (intra-assay CV=8%), a high intra-culture variability was observed with LCL (intra-culture CV=16.8%). Neither differences on OGG1 gene expression nor the cell-cycle distribution seemed to account for this variability. Inter-individual variability of OGG activity in PBMC and LCL was not associated with OGG1 gene expression. We have therefore established a non-radioactive cleavage assay that can be easily applied to measure OGG activity in human PBMC. The use of LCL for DNA-repair genotype-phenotype correlation studies seems to be inappropriate, at least with cell-free based functional assays.
    • Accelerated (32)P-HPLC for bulky DNA adducts.

      Nagy, Eszter; Cornelius, Michael G.; Moller, Lennart (2009-03)
      Many compounds can react with DNA forming covalent modifications, so-called DNA adducts, which can influence crucial biological processes. DNA adducts from various DNA-damaging agents can act both as biomarkers and as a measurement of the actual damage of the genome. Therefore, they are of value in determining exposed or sensitive individuals or populations and in identifying agents that can induce DNA damage. A common method to measure DNA adducts is through DNA hydrolysis, adduct enrichment, (32)P-post-labelling and chromatographic separation. High-performance liquid chromatography (HPLC) with online radioactivity detection, the (32)P-HPLC (direct injection of the (32)P-labelled mixture into the HPLC with online (32)P-detection) method, gives both high sensitivity and good resolution of complex mixtures of DNA adducts. One limitation with this method is the capacity when dealing with large numbers of samples. The aim of this study was therefore to increase the analytical capacity by reducing analysis time of the (32)P-HPLC method. A change of HPLC columns to low backpressure columns and adaptation of elution conditions enabled a reduction in time per analysis from 100 to 20 min. This did not affect sensitivity but lowered chromatographic resolution, although bulky DNA adducts were still well resolved from other DNA components. This is useful when the total amount of DNA adducts is the primary interest. When high resolution is required, this can be achieved by gradient modifications, which increase the time required per analysis to 30 min. The accelerated (32)P-HPLC increases the capacity in number of samples 3- to 5-fold, depending on resolution requirements, without any negative effect on sensitivity in both in vitro and in vivo samples.
    • Activated neutrophils inhibit nucleotide excision repair in human pulmonary epithelial cells: role of myeloperoxidase.

      Güngör, Nejla; Godschalk, Roger W.L.; Pachen, Daniëlle M.; Van Schooten, Frederik J.; Knaapen, Ad M. (The Federation of American Societies for Experimental Biology, 2007-08)
      Neutrophils are thought to affect pulmonary carcinogenesis by promoting the metabolism of inhaled chemical carcinogens, causing enhanced formation of promutagenic DNA adducts. We hypothesized that neutrophils interfere with the removal of such DNA adducts by inhibiting nucleotide excision repair (NER) in target cells. Human alveolar epithelial cells (A549) were cocultured with activated neutrophils, and we observed a significant reduction of NER in the A549 cells, which was abrogated by addition of the myeloperoxidase (MPO) inhibitor 4-aminobenzoic acid hydrazide. The inhibitory effect of neutrophils could be mimicked by the MPO product hypochlorous acid (HOCl), which caused an acute, dose-dependent inhibition of NER in A549 cells. This was independent of cytotoxicity or ATP loss and persisted up to 24 h. These data were supported by showing that HOCl caused a delayed removal of DNA adducts in benzo[a]pyrene-diolepoxide-exposed A549 cells. The acute HOCl-induced inhibition of NER can only partly be explained by oxidative modification of repair proteins. To explain the more persistent effects of HOCl, we analyzed the expression of NER genes and found that HOCl significantly reduced XPC expression. In conclusion, these data indicate that neutrophils are potent inhibitors of nucleotide excision repair. This may provide a further biological explanation for the association between inflammation and lung cancer development.
    • Acute hypoxia and reoxygenation-induced DNA oxidation in human mononuclear blood cells.

      Risom, Lotte; Lundby, Carsten; Thomsen, Jonas Juhl; Mikkelsen, Lone; Loft, Steffen; Friis, Gitte; Moller, Peter (2007-12-01)
      Research indicates that exposure to hypoxia is associated with oxidative stress. In this investigation, healthy subjects were exposed to hypoxia by inhalation of 10% oxygen for 2h (corresponding to 5500m above sea level). The levels of strand breaks and oxidatively damaged purine bases, measured by the comet assay, and the expression of genes involved in DNA repair of oxidatively damaged DNA were investigated in mononuclear blood cells (MNBC) at baseline, after 2h of hypoxia, 2h of reoxygenation, and 1 day and 8 days after the exposure. The level of strand breaks and oxidized purine bases in MNBC increased following both the 2h of hypoxia and the 2h reoxygenation period, whereas this effect was not observed in unexposed subjects. The expressions of oxoguanine DNA glycosylase 1 (OGG1), nucleoside diphosphate linked moiety X-type motif 1 (NUDT1), nei endonuclease VIII-like 1 (NEIL1), and mutY homolog (MUTYH) were unaltered throughout the experiment in both groups of subjects, indicating that DNA repair genes are not up-regulated by the hypoxia and reoxygenation treatment. Taken together, this report shows that inhalation of 10% oxygen for 2h is associated with increased number of oxidized DNA lesions in MNBC, but acute hypoxia may not inflict upon the regulation of genes involved in repair of oxidized DNA.
    • Adherence to a Mediterranean diet and risk of gastric adenocarcinoma within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort study.

      Buckland, Genevieve; Agudo, Antonio; Luján, Leila; Jakszyn, Paula; Bueno-de-Mesquita, H. Bas; Palli, Domenico; Boeing, Heiner; Carneiro, Fátima; Krogh, Vittorio; Sacerdote, Carlotta; et al. (2010-02)
      BACKGROUND: The Mediterranean dietary pattern is believed to protect against cancer, although evidence from cohort studies that have examined particular cancer sites is limited. OBJECTIVE: We aimed to explore the association between adherence to a relative Mediterranean diet (rMED) and incident gastric adenocarcinoma (GC) within the European Prospective Investigation into Cancer and Nutrition study. DESIGN: The study included 485,044 subjects (144,577 men) aged 35-70 y from 10 European countries. At recruitment, dietary and lifestyle information was collected. An 18-unit rMED score, incorporating 9 key components of the Mediterranean diet, was used to estimate rMED adherence. The association between rMED and GC with respect to anatomic location (cardia and noncardia) and histologic types (diffuse and intestinal) was investigated. A calibration study in a subsample was used to control for dietary measurement error. RESULTS: After a mean follow-up of 8.9 y, 449 validated incident GC cases were identified and used in the analysis. After stratification by center and age and adjustment for recognized cancer risk factors, high compared with low rMED adherence was associated with a significant reduction in GC risk (hazard ratio: 0.67; 95% CI: 0.47, 0.94). A 1-unit increase in the rMED score was associated with a decreased risk of GC of 5% (95% CI: 0.91, 0.99). There was no evidence of heterogeneity between different anatomic locations or histologic types. The calibrated results showed similar trends (overall hazard ratio for GC: 0.93; 95% CI: 0.89, 0.99). CONCLUSION: Greater adherence to an rMED is associated with a significant reduction in the risk of incident GC.
    • Adulthood lifetime physical activity and breast cancer.

      Peplonska, Beata; Lissowska, Jolanta; Hartman, Terryl J.; Szeszenia-Dabrowska, Neonila; Blair, Aaron; Zatonski, Witold; Sherman, Mark E.; Garcia-Closas, Montserrat; Brinton, Louise A. (2008-03)
      BACKGROUND: Epidemiologic studies have shown that breast cancer risk is reduced 30% to 40% in highly physically active compared with inactive women. However, the effects of moderate activities, timing of activities, and intervening effects of other risk factors remain less clear. METHODS: We analyzed data on physical activity patterns in 2176 incident breast cancer cases and 2326 controls in a population-based breast cancer case-control study in Poland conducted in 2000-2003. Using unconditional logistic regression analyses, we calculated odds ratios (ORs) and 95% confidence intervals (CIs) associated with physical activity levels (measured by average metabolic equivalents of energy expenditure hours per week), controlling for potential confounders. RESULTS: Total adult lifetime activity reduced risk of breast cancer, with individuals in the highest quartile having an OR of 0.80 (CI = 0.67-0.96) compared with the lowest quartile. Reduced risks were most consistent for the highest quartiles of moderate-to-vigorous activities: moderate/vigorous recreational activities (OR = 0.74; CI = 0.62-0.89), outdoor activities (0.81; 0.68-0.97), heavy physical work (0.60; 0.42-0.87), and combined high intensity (metabolic equivalent >6.0) activities (0.75; 0.63-0.90). These relations were not modified by body mass index, menopausal status, or family history of breast cancer. Reductions in risk with moderate/vigorous recreational activities were stronger for larger tumors and those with nodal involvement. Women who increased their recreational activity in their 50s had significantly reduced risk, with those in the highest tertile of change being at a 27% lower risk. CONCLUSIONS: Leisure-time moderate-to-vigorous activities reduce breast cancer risk irrespective of underlying host characteristics.
    • Aging and defense against generation of 8-oxo-7,8-dihydro-2'-deoxyguanosine in DNA.

      Mikkelsen, Lone; Bialkowski, Karol; Risom, Lotte; Lohr, Mille; Loft, Steffen; Moller, Peter (2009-09-01)
      The imbalance between the formation of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) in DNA and the efficiency of cellular systems of DNA protection and repair is considered an important factor in the age-dependent development of cancer. This study investigated the relationship between oxidatively damaged DNA and the activity of the DNA repair system and 8-oxo-7,8-dihydro-2'-deoxyguanosine 5'-triphosphate pyrophosphohydrolase (8-oxodGTPase) activity in liver and lung tissue from mice at 10-100 weeks of age. The level of 8-oxodG increased with age, whereas the level of formamidopyrimidine DNA glycosylase sites was unaltered. The enzyme activity toward single oxygen-induced DNA damage and mRNA expression levels of Ercc1, Neil1, and Ogg1 remained unaltered with age. However, the 8-oxodGTPase activity in the liver was 18% (95% CI: 0.2-37%) lower in mice at 25 and 50 weeks than in 10-week-old mice. The 10- and 100-week-old mice had similar 8-oxodGTPase activity. In contrast, the mRNA expression of Nudt1 was statistically unaltered that likely resulted from higher variation of measurements. The accumulation of 8-oxodG with age is not a direct consequence of decreased enzyme activity toward singlet oxygen-induced substrate DNA. An age-related higher level of 8-oxodG even occurs concomitantly with high 8-oxodGTPase activity.
    • AHR- and DNA-damage-mediated gene expression responses induced by benzo(a)pyrene in human cell lines.

      Hockley, Sarah L.; Arlt, Volker M.; Brewer, Daniel; Te Poele, Robert; Workman, Paul; Giddings, Ian; Phillips, David H. (2007-12)
      Carcinogens induce complex transcriptional responses in cells that may hold key mechanistic information. Benzo(a)pyrene (BaP) modulation of transcription may occur through the activation of the aryl hydrocarbon receptor (AHR) or through responses to DNA damage. To characterize further the expression profiles induced by BaP in HepG2 and MCF-7 cells obtained in our previous study, they were compared to those induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), which activates AHR but does not bind to DNA, and anti-benzo(a)pyrene- trans-7,8-dihydrodiol-9,10-epoxide (BPDE), which binds directly to DNA but does not activate AHR. A total of 22 genes had altered expression in MCF-7 cells after both BaP and TCDD exposure, and a total of 29 genes had altered expression in HepG2 cells. In both cell lines, xenobiotic metabolism was upregulated through induction of NQO1, MGST1, and CYP1B1. A total of 78 expression changes were induced by both BaP and BPDE in MCF-7 cells, and a total of 29 expression changes were induced by both BaP and BPDE in HepG2 cells. These genes were predominantly involved in cell cycle regulation, apoptosis, and DNA repair. BaP and BPDE caused the repression of histone genes in both cell lines, suggesting that regulation of these genes is an important component of the DNA damage response. Interestingly, overlap of the BPDE and TCDD gene expression profiles was also observed. Furthermore, some genes were modulated by BaP but not by TCDD or BPDE, including induction of CRY1 and MAK, which may represent novel signaling pathways that are independent of both AHR activation and DNA damage. Promoter analysis identified candidate genes for direct transcriptional regulation by either AHR or p53. These analyses have further dissected and characterized the complex cellular response to BaP.
    • Air pollution, oxidative damage to DNA, and carcinogenesis.

      Moller, Peter; Folkmann, Janne Kjaersgaard; Forchhammer, Lykke; Brauner, Elvira Vaclavik; Danielsen, Pernille Hogh; Risom, Lotte; Loft, Steffen (2008-07-18)
      There is growing concern that air pollution exposure increases the risk of lung cancer. The mechanism of action is related to particle-induced oxidative stress and oxidation of DNA. Humans exposed to urban air with vehicle emissions have elevated levels of oxidized guanine bases in blood cells and urine. Animal experimental studies show that pulmonary and gastrointestinal exposure is associated with elevated levels of oxidized guanines in the lung and other organs. Collectively, there is evidence indicating that exposure to traffic-related air pollution particles is associated with oxidative damage to DNA and this might be associated with increased risk of cancer.
    • Antiapoptotic effects of dietary antioxidants towards N-nitrosopiperidine and N-nitrosodibutylamine-induced apoptosis in HL-60 and HepG2 cells.

      Garcia, Almudena; Morales, Paloma; Arranz, Nuria; Delgado, Ma Eugenia; Rafter, Joseph; Haza, Ana I. (2009-07)
      The aim of this work was to determine the effect of vitamin C, diallyl disulfide (DADS) and dipropyl disulfide (DPDS) towards N-nitrosopiperidine (NPIP) and N-nitrosodibutylamine (NDBA)-induced apoptosis in human leukemia (HL-60) and hepatoma (HepG2) cell lines using the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay. None of the vitamin C (5-50 microm), DADS and DPDS (1-5 microm) concentrations selected induced a significant percentage of apoptosis. In simultaneous treatments, vitamin C, DADS and DPDS reduced the apoptosis induced by NPIP and NDBA in HL-60 and HepG2 cells (around 70% of reduction). We also investigated its scavenging activities towards reactive oxygen species (ROS) produced by NPIP and NDBA using 2',7'-dichlorodihydrofluorescein diacetate in both cell lines. ROS production induced by both N-nitrosamine was reduced to control levels by vitamin C (5-50 microm) in a dose-dependent manner. However, DADS (5 microm) increased ROS levels induced by NPIP and NDBA in HL-60 (40 and 20% increase, respectively) and HepG2 cells (18% increase), whereas DPDS was more efficient scavenger of ROS at the lowest concentration (1 microm) in both HL-60 (52 and 25% reduction, respectively) and HepG2 cells (24% reduction). The data demonstrated that the scavenging ability of vitamin C and DPDS could contribute to inhibition of the NPIP- and NDBA-induced apoptosis. However, more than one mechanism, such as inhibition of phase I and/or induction of phase II enzymes, could be implicated in the protective effect of dietary antioxidants towards NPIP- and NDBA-induced apoptosis in HL-60 and HepG2 cells.
    • Anticarcinogenic compounds of olive oil and related biomarkers.

      Sotiroudis, Theodore G.; Kyrtopoulos, Soterios A. (2008-05)
      Olive oil, one of the oldest vegetable oils consumed without any refining, is associated with a reduced risk of a number of common cancers. Minor constituents of virgin olive oil have been suggested to be among the major chemopreventive components. A brief overview is presented of recent findings concerning the bioavailability of certain important olive oil minor components including efficient antioxidant polyphenols, the triterpene hydrocarbon squalene and beta-sitosterol, considered as putative nutritional biomarkers, in relation to the incidence of cancer.
    • Antioxidant vitamins and cancer risk: is oxidative damage to DNA a relevant biomarker?

      Loft, Steffen; Moller, Peter; Cooke, Marcus S.; Rozalski, Rafal; Olinski, Ryszard (2008-05)
      Oxidative damage to DNA is regarded as an important step in carcinogenesis. These lesions may arise as a consequence of exposure to xenobiotics, but are also generated as a consequence of endogenous generation of oxidizing compounds. Measurements of oxidative damage to guanines, such as 8-oxo-7, 8-dihydroguanine (8-oxodG) are increasingly being regarded as reliable biomarkers of oxidative stress and they may have a predictive value of cancer risk, although this needs to be established independently in several cohort studies. A survey of intervention studies of the ingestion of antioxidant-containing foods or tablets of antioxidants indicate that about one-third of the studies reported a protective effect in terms of lower levels of oxidative damage to DNA in white blood cells or decreased urinary excretion of 8-oxodG. Although firm conclusions cannot be reached, there appears to be links between ingestion of antioxidants, oxidative damage to DNA, and risk of cancer.
    • Antiproliferative activity of extracts of some Bolivian medicinal plants.

      Rodrigo, Gloria C.; Almanza, Giovanna R.; Akesson, Bjorn; Duan, Rui-Dong (2010-11-04)
      Twenty-six plant species from the native flora used in Bolivian folk medicine were selected for studies of bioactivity. They belonged to the following families namely: Asteraceae (11), Brassicaceae (1), Cactaceae (1), Caesalpinaceae (2), Chenopodiaceae (1), Frankeniaceae (1), Geraniaceae (1), Laureaceae (1), Oxalidaceae (1), Piperaceae (1), Plantaginaceae (1), Rosaceae (1), Solanaceae (1) and Verbenaceae (2). Their effects on the proliferation of colon cancer cells (Caco-2) were studied using the WST-1 reagent. The results indicated that four out of 26 ethanolic extracts had a significant antiproliferative activity in this assay from (Schkuhria pinnata, Piper longestylosum, Parastrephia lepidophylla and Erodium cicutarium). The bioactivity of the extracts was correlated with the phytochemical characterization. Further studies of the mechanism of action of the bioactive extracts are needed.
    • Antiproliferative effects of curcuphenol, a sesquiterpene phenol.

      Rodrigo, Gloria; Almanza, Giovanna R.; Cheng, Yajun; Peng, Jiangnan; Hamann, Mark; Duan, Rui-Dong; Akesson, Bjorn (2010-10)
      Curcuphenol is a sesquiterpene isolated from sponges and plants having several significant biological activities. The present study explored its effect on cell proliferation and apoptosis in Caco-2 human colon cancer cells. It was demonstrated that curcuphenol in concentrations in the range of 29-116 µg/ml inhibited cell proliferation and DNA replication and induced cell death in a dose-dependent manner. The induction of apoptosis was associated with a stimulation of the activity of caspase-3. The findings presented here suggest that curcuphenol has antiproliferative and pro-apoptotic properties.
    • Application of OMICS technologies in occupational and environmental health research; current status and projections.

      Vlaanderen, J.; Moore, L. E.; Smith, M. T.; Lan, Q.; Zhang, L.; Skibola, C. F.; Rothman, N.; Vermeulen, R. (2010-02)
      OMICS technologies are relatively new biomarker discovery tools that can be applied to study large sets of biological molecules. Their application in human observational studies (HOS) has become feasible in recent years due to a spectacular increase in the sensitivity, resolution and throughput of OMICS-based assays. Although, the number of OMICS techniques is ever expanding, the five most developed OMICS technologies are genotyping, transcriptomics, epigenomics, proteomics and metabolomics. These techniques have been applied in HOS to various extents. However, their application in occupational environmental health (OEH) research has been limited. Here, we will discuss the opportunities these new techniques provide for OEH research. In addition we will address difficulties and limitations to the interpretation of the data that is generated by OMICS technologies. To illustrate the current status of the application of OMICS in OEH research, we will provide examples of studies that used OMICS technologies to investigate human health effects of two well-known toxicants, benzene and arsenic.
    • Aristolochic acid mutagenesis: molecular clues to the aetiology of Balkan endemic nephropathy-associated urothelial cancer.

      Arlt, Volker M.; Stiborova, Marie; vom Brocke, Jochen; Simoes, Maria L.; Lord, Graham M.; Nortier, Joelle L.; Hollstein, Monica; Phillips, David H.; Schmeiser, Heinz H. (2007-11)
      Balkan endemic nephropathy (BEN) is found in certain rural areas of the Balkans and affects at least 25,000 inhabitants. Of the many hypotheses on BEN, the Aristolochia hypothesis has recently gained ground substantiated by the investigations on aristolochic acid nephropathy (AAN). On both clinical and morphological grounds, AAN is very similar to BEN. That exposure to aristolochic acid (AA) of individuals living in endemic areas through consumption of bread made with flour contaminated with seeds of Aristolochia clematitis is responsible for BEN is an old hypothesis, but one which is fully consistent with the unique epidemiologic features of BEN. Here, we propose an approach to investigate AA-induced mutagenesis in BEN that can provide molecular clues to the aetiology of its associated urothelial cancer. The molecular mechanism of AA-induced carcinogenesis demonstrates a strong association between DNA adduct formation, mutation pattern and tumour development. A clear link between urothelial tumours, p53 mutations and AA exposure should emerge as more tumour DNA from BEN patients from different endemic areas becomes available for mutation analysis. We predict that the observed p53 mutation spectrum will be dominated by AT --> TA transversion mutations as has already been demonstrated in the human p53 gene of immortalized cells after exposure to AAI and urothelial tumours from BEN patients in Croatia. Moreover, the detection of AA-specific DNA adducts in renal tissue of a number of BEN patients and individuals living in areas endemic for BEN in Croatia provides new evidence that chronic exposure to AA is a risk factor for BEN and its associated cancer.
    • Aromatic DNA adducts and polymorphisms in metabolic genes in healthy adults: findings from the EPIC-Spain cohort.

      Agudo, Antonio; Peluso, Marco; Sala, Nuria; Capella, Gabriel; Munnia, Armelle; Piro, Sara; Marin, Fatima; Ibanez, Raquel; Amiano, Pilar; Tormo, M. Jose; et al. (2009-06)
      Aromatic compounds such as polycyclic aromatic hydrocarbons, arylamines and heterocyclic amines require metabolic activation to form metabolites able to bind to DNA, a process mediated by polymorphic enzymes. We measured aromatic DNA adducts in white blood cells by the (32)P-post-labelling assay in a sample of 296 healthy adults (147 men and 149 women) from five regions of Spain. We also analyzed functional polymorphisms in the metabolic genes CYP1A1, CYP1A2, EPHX1, GSTM1, GSTT1, NAT2 and SULT1A1. A significant increased level of DNA aromatic adducts was found related to the fast oxidation-hydrolysis phenotype defined by the polymorphism I462V in CYP1A1, the allele A in IVS1-154C>A of CYP1A2 and the combination Tyrosine-Arginine for Y113H and H139R of EPHX1. Geometric means (adducts per 10(-9) normal nucleotides) were 2.17, 4.04 and 6.30 for slow, normal and fast phenotypes, respectively (P-trend = 0.01). Slow acetylation by NAT2 was associated with a significant decrease in adduct level; subjects with slow alleles *5A and *7A/B had in average 1.56 x 10(-9)adducts, as compared with 5.60 for those with normal NAT2 activity (P-value = 0.01). No association was seen with polymorphisms of other metabolic genes such as GSTM1, GSTT1 or SULT1A1. We concluded that the metabolic pathways of oxidation, hydrolysis and acetylation are relevant to the formation of bulky DNA adducts. This could suggest a potential involvement of aromatic compounds in the formation of such adducts; however, given lack of specificity of the post-labeling assay, a firm conclusion cannot be drawn.