Miriam C. Poirier

National Institutes of Health, 베서스다, Maryland, United States

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Publications (184)827.21 Total impact

  • Kathyayini V Divi · Yvona Ward · Miriam C Poirier · Ofelia A Olivero ·
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    ABSTRACT: Primary cilia arise from the centrosomes of quiescent or post-mitotic cells, and serve as sensory organelles that communicate mechanical and chemical stimuli from the environment to the interior of the cell. Cilium formation may, therefore, become a useful end point signaling exposure to genotoxins or aneugens. Here we have used the aneugen, zidovudine (AZT), an antiretroviral drug that induces DNA replication arrest and centrosomal amplification (>2 centrosomes per quiescent cell), to evaluate cilia formation in retinal epithelial (pigmented) cells. Since cilia are derived from centrosomes, and aneugens can induce centrosomal amplification, the production of multiple cilia arising from multiple centrosomes may reveal the aneugenic nature of the agents. Cells were exposed to AZT to induce centrosomal amplification, cultured without serum to allow the centrioles to develop cilia, and immunostained to visualize cilia and centrosomes. Nuclear DNA was stained with DAPI. Preliminary observations suggest that cells with multiple centrosomes are able to generate extra cilia. © 2015 by John Wiley & Sons, Inc.
    Current protocols in toxicology 11/2015; 66:3.13.1-3.13.8. DOI:10.1002/0471140856.tx0313s66
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    ABSTRACT: Here we present fetal genotoxicity and mitochondrial toxicity, induced by nucleoside reverse transcriptase inhibitors (NRTIs), in HIV-1-infected pregnant women treated to prevent mother-to-child HIV-1 transmission, and in virus-free pregnant patas monkeys. In the offspring of pregnant patas monkeys given human-equivalent NRTI protocols, aneuploidy was found in cultured bone marrow cells taken at birth, 1, and 3 years of age. In some newborn human infants, the offspring of HIV-1-infected mothers given zidovudine (AZT) therapy, aneuploidy, mitochondrial DNA (mtDNA) depletion, morphologically damaged mitochondria, and reduction in cardiac left ventricular muscle were observed. NRTI-exposed human and patas umbilical cords had similar levels of mtDNA depletion and mitochondrial morphological damage. NRTI-exposed patas offspring showed a compensatory increase in heart mtDNA, and a 50% loss of brain mtDNA at 1 year of age. Mitochondrial morphological damage and mtDNA loss were persistent in blood cells of NRTI-exposed infants up to 2 years of age, and in heart and brain from NRTI-exposed patas up to 3 years of age (human equivalent of 15 years). Whereas use of NRTIs in human pregnancy protects many thousands of children worldwide, some HIV-1-uninfected infants born to HIV-1-infected mothers receiving antiretroviral drug therapy sustain toxicities that may have adverse consequences later in life.
    Current Opinion in Pediatrics 01/2015; 27(2). DOI:10.1097/MOP.0000000000000193 · 2.53 Impact Factor
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    ABSTRACT: The nucleoside reverse transcriptase inhibitor zidovudine (AZT) induces genotoxic damage that includes centrosomal amplification (CA > 2 centrosomes/cell) and micronucleus (MN) formation. Here we explored these end points in mice deficient in DNA repair and tumor suppressor function to evaluate their effect on AZT-induced DNA damage. We used mesenchymal-derived fibroblasts cultured from C57BL/6J mice that were null and wild type (WT) for Xpa, and WT, haploinsufficient and null for p53 (6 different genotypes). Dose-responses for CA formation, in cells exposed to 0, 10, and 100 μM AZT for 24 hr, were observed in all genotypes except the Xpa(+/+)p53(+/−) cells, which had very low levels of CA, and the Xpa(−/−)p53(−/−) cells, which had very high levels of CA. For CA there was a significant three-way interaction between Xpa, p53, and AZT concentration, and Xpa(−/−) cells had significantly higher levels of CA than Xpa(+/+) cells, only for p53(+/−) cells. In contrast, the MN and MN + chromosomes (MN + C) data showed a lack of AZT dose response. The Xpa(−/−) cells, with p53(+/+) or (+/−) genotypes, had levels of MN and MN + C higher than the corresponding Xpa(+/+) cells. The data show that CA is a major event induced by exposure to AZT in these cells, and that there is a complicated relationship between AZT and CA formation with respect to gene dosage of Xpa and p53. The loss of both genes resulted in high levels of damage, and p53 haploinsufficicency strongly protected Xpa(+/+) cells from AZT-induced CA damage. Environ. Mol. Mutagen., 2014. © 2014 Wiley Periodicals, Inc.
    Environmental and Molecular Mutagenesis 12/2014; 55(9). DOI:10.1002/em.21889 · 2.63 Impact Factor
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    ABSTRACT: The nucleoside reverse transcriptase inhibitors (NRTIs), used for treatment of the human immunodeficiency virus-1, compromise mitochondria in cardiomyocytes and other host cells, limiting the clinical use of these drugs. To explore underlying mechanisms, we overexpressed PGC-1α, a master regulator of mitochondrial biogenesis, twofold in H9c2 rat cardiomyocyte cultures, hypothesizing that this might protect the mitochondria from damage induced by the NRTI combination zidovudine (AZT) and didanosine (ddI). The experimental groups, evaluated during 16 passages (P) of drug exposure, included: PGC-1α-overexpressing cells with no exposure, or exposure to 50 µM AZT plus 50 µM ddI; and control cells with no exposure or exposure to the same doses of AZT and ddI. The AZT/ddI combination caused a growth inhibition of 15-20 % in control cells, but none in PGC-1α cells. Apoptosis was highest in AZT/ddI-exposed control cells, and PGC-1α overexpression protected cells from AZT/ddI-induced apoptosis. At P3, P6, P8, and P12, uncoupled mitochondrial oxygen consumption rate, determined by Seahorse 24 XF Analyzer, as higher in AZT/ddI-exposed PGC-1α cells, compared to AZT/ddI-exposed control cells (p < 0.05 at all P). Complex I activity was higher in AZT/ddI-exposed PGC-1α overexpressing cells than that in AZT/ddI-exposed control cells (p < 0.05), and reactive oxygen species levels were lower in PGC-1α overexpressing cells than that in control cells (p < 0.05) when both were exposed to AZT/ddI. Taken together, these experiments show proof of concept that overexpression of PGC-1α protects cardiomyocytes from NRTI-induced toxicity, and suggest that a pharmaceutical agent with similar activity may protect against NRTI-induced mitochondrial toxicity.
    Cardiovascular Toxicology 11/2014; 15(3). DOI:10.1007/s12012-014-9288-5 · 1.72 Impact Factor
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    ABSTRACT: The polycyclic aromatic hydrocarbon (PAH) benzo(a)pyrene (BP) is thought to bind covalently to DNA, through metabolism by cytochrome P450 1A1 (CYP1A1) and CYP1B1, and other enzymes, to form r7, t8, t9-trihydroxy-c-10-(N 2-deoxyguanosyl)-7,8,9,10-tetrahydro-benzo[a]-pyrene (BPdG). Evaluation of RNA expression data, to understand the contribution of different metabolic enzymes to BPdG formation, is typically presented as fold-change observed upon BP exposure, leaving the actual number of RNA transcripts unknown. Here, we have quantified RNA copies/ng cDNA (RNA cpn) for CYP1A1 and CYP1B1, as well as NAD(P)H:quinone oxidoreductase 1 (NQO1), which may reduce formation of BPdG adducts, using primary normal human mammary epithelial cell (NHMEC) strains, and the MCF-7 breast cancer cell line. In unexposed NHMECs, basal RNA cpn values were 58–836 for CYP1A1, 336–5587 for CYP1B1 and 5943–40112 for NQO1. In cells exposed to 4.0 µM BP for 12h, RNA cpn values were 251–13234 for CYP1A1, 4133–57078 for CYP1B1 and 4456–55887 for NQO1. There were 3.5 (mean, range 0.2–15.8) BPdG adducts/108 nucleotides in the NHMECs (n = 16), and 790 in the MCF-7s. In the NHMECs, BP-induced CYP1A1 RNA cpn was highly associated with BPdG (P = 0.002), but CYP1B1 and NQO1 were not. Western blots of four NHMEC strains, chosen for different levels of BPdG adducts, showed a linear correlation between BPdG and CYP1A1, but not CYP1B1 or NQO1. Ethoxyresorufin-O-deethylase (EROD) activity, which measures CYP1A1 and CYP1B1 together, correlated with BPdG, but NQO1 activity did not. Despite more numerous levels of CYP1B1 and NQO1 RNA cpn in unexposed and BP-exposed NHMECs and MCF-7cells, BPdG formation was only correlated with induction of CYP1A1 RNA cpn. The higher level of BPdG in MCF-7 cells, compared to NHMECs, may have been due to a much increased induction of CYP1A1 and EROD. Overall, BPdG correlation was observed with CYP1A1 protein and CYP1A1/1B1 enzyme activity, but not with CYP1B1 or NQO1 protein, or NQO1 enzyme activity.
    Mutagenesis 09/2014; 29(6). DOI:10.1093/mutage/geu049 · 2.79 Impact Factor
  • Miriam C. Poirier · Jeffrey L. Schwartz · Marilyn J. Aardema ·
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    ABSTRACT: One of the goals of the EMGS is to help members achieve professional success in the fields they have trained in. Today, there is greater competition for jobs in genetic toxicology, genomics, and basic research than ever before. In addition, job security and the ability to advance in one's career is challenging, regardless of whether one works in a regulatory, academic, or industry environment. At the EMGS Annual Meeting in Monterey, CA (September, 2013), the Women in EMGS Special Interest Group held a workshop to discuss strategies for achieving professional success. Presentations were given by three speakers, each representing a different employment environment: Government (Miriam C. Poirier), Academia (Jeffrey L. Schwartz), and Industry (Marilyn J. Aardema). Although some differences in factors or traits affecting success in the three employment sectors were noted by each of the speakers, common factors considered important for advancement included networking, seeking out mentors, and developing exceptional communication skills. Environ. Mol. Mutagen., 2014. © 2014 Wiley Periodicals, Inc.
    Environmental and Molecular Mutagenesis 08/2014; 55(7). DOI:10.1002/em.21871 · 2.63 Impact Factor
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    ABSTRACT: The cytokinesis-block micronucleus cytome (CBMN) assay, introduced by Fenech, was used to demonstrate different types of DNA damage in MOLT-3 human lymphoblastoid cells exposed to 10 μM zidovudine (AZT). In addition, we explored the cytoprotective potential of two antioxidants, WR-1065 and Tempol, to decrease AZT-induced genotoxicity. Binucleated cells, arrested by Cytochalasin B (Cyt B), were evaluated for micronuclei (MN), caused by DNA damage or chromosomal loss, and chromatin nucleoplasmic bridges (NPBs), caused by telomere attrition. Additionally, nuclear buds (NBUDs), caused by amplified DNA, and apoptotic and necrotic (A/N) cells were scored. We hypothesized that AZT exposure would increase the frequency of genotoxic end points, and that the antioxidants Tempol and WR-1065 would protect against AZT-induced genotoxicity. MOLT-3 cells were exposed to 0 or 10 µM AZT for a total of 76 hr. After the first 24 hr, 0 or 5 µM WR-1065 and/or 0 or 200 µM Tempol were added for the remainder of the experiment. For the last 28 hr (of 76 hr), Cyt B was added to arrest replication after one cell division, leaving a predominance of binucleated cells. The nuclear division index (NDI) was similar for all treatment groups, indicating that the exposures did not alter cell viability. MOLT-3 cells exposed to AZT alone had significant (P < 0.05) increases in MN and NBs, compared to unexposed cells. Both Tempol and WR-1065 protected against AZT-induced MN formation (P < 0.003 for both), and WR-1065, but not Tempol, reduced the levels of A/N (P = 0.041). In cells exposed to AZT/Tempol there were significantly reduced levels of NBUDs, compared to cells exposed to AZT alone (P = 0.015). Cells exposed to AZT/WR-1065 showed reduced levels of NPBs, compared to cells exposed to AZT alone (P = 0.037). Thus WR-1065 and Tempol protected MOLT-3 cells against specific types of AZT-induced DNA damage. Environ. Mol. Mutagen., 2014. © 2014 Wiley Periodicals, Inc.
    Environmental and Molecular Mutagenesis 08/2014; 55(7). DOI:10.1002/em.21872 · 2.63 Impact Factor
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    ABSTRACT: Antiretroviral drugs have proved useful in the clinical management of HIV-infected persons, though there are concerns about the effects of exposure to these DNA-reactive drugs. We investigated the potential of the plant model Allium cepa root tip assay to demonstrate the cytogenotoxicity of zidovudine and nevirapine and as a replace-reduce-refine programme amenable to resource-poor research settings. Cells mitotic index were determined in squashed root cells from Allium cepa bulbs exposed to zidovudine or nevirapine for 48 hr. The concentration of zidovudine and nevirapine inhibiting 50% root growth after 96 hr exposure was 65.0 µM and 92.5 µM respectively. Root length of all antiretroviral-exposed roots after 96 hr exposure was significantly shorter than the unexposed roots while additional root growth during a subsequent 48 hr recovery period in the absence of drug was not significantly different. By ANOVA, there was a significant association between percentage of cells in mitosis and zidovudine dose (p = 0.004), but not nevirapine dose (p = 0.68). Chromosomal aberrations such as sticky chromosomes, chromatin bridges, multipolar mitoses and binucleated cells were observed in root cells exposed to zidovudine and nevirapine for 48 hr. The most notable chromosomal aberration was drug-related increases in sticky chromosomes. Overall, the study showed inhibition in root length growth, changes in the mitotic index, and the induction of chromosomal aberrations in Allium bulbs treated for 96 hr or 48 hr with zidovudine and nevirapine. The study reveals generalized cytogenotoxic damage induced by exposure to zidovudine and nevirapine, and further show that the two compounds differ in their effects on mitosis and the types of chromosomal aberrations induced.
    PLoS ONE 03/2014; 9(3):e90296. DOI:10.1371/journal.pone.0090296 · 3.23 Impact Factor
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    ABSTRACT: NRTIs, essential components of combinational therapies used for treatment of HIV-1, damage heart mitochondria. Here we have shown mitochondrial compromise in H9c2 rat cardiomyocytes exposed for 16 passages (P) to the NRTIs Zidovudine (AZT, 50 μM) and Didanosine (ddI, 50 μM), and we have demonstrated protection from mitochondrial compromise in cells treated with 200 μM Tempol or 200 μM Tempol-H, along with AZT/ddI, for 16P. Exposure to AZT/ddI caused a moderate growth inhibition at P3, P5, P7 and P13, which was not altered by addition of Tempol or Tempol-H. Mitochondrial oxidative phosphorylation (OXPHOS) capacity was determined as uncoupled Oxygen Consumption Rate (OCR) by Seahorse XF24 Analyzer. At P5, P7 and P13, AZT/ddI-exposed cells showed an OCR reduction of 8.8-57.2% in AZT/ddI-exposed cells, compared to unexposed cells. Addition of Tempol or Tempol-H, along with AZT/ddI, resulted in OCR levels increased by about 300% above the values seen with AZT/ddI alone. The Seahorse data were further supported by electron microscopy (EM) studies in which P16 cells exposed to AZT/ddI/Tempol had less mitochondrial pathology than P16 cells exposed to AZT/ddI. Western blots of P5 cells showed that Tempol and Tempol-H upregulated expression of mitochondrial uncoupling protein-2 (UCP-2). However, Complex I activity that was reduced by AZT/ddI, was not restored in the presence of AZT/ddI/Tempol. Superoxide levels were increased in the presence of AZT/ddI and significantly decreased in cells exposed to AZT/3TC/Tempol at P3, P7 and P10. In conclusion, Tempol protects against NRTI-induced mitochondrial compromise, and UCP-2 plays a role through mild uncoupling.
    Toxicological Sciences 03/2014; 139(1). DOI:10.1093/toxsci/kfu034 · 3.85 Impact Factor
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    ABSTRACT: The estrogen analog tamoxifen (TAM), used for adjuvant therapy of breast cancer, induces endometrial and uterine tumors in breast cancer patients. Proliferation stimulus of the uterine endometrium is likely involved in tumor induction, but genotoxicity may also play a role. Formation of TAM–DNA adducts in human tissues has been reported but remains controversial. To address this issue, we examined TAM–DNA adducts in uteri from two species of monkeys, Erythrocebus patas (patas) and Macaca fascicularis (macaque), and in human endometrium and myometrium. Monkeys were given 3–4 months of chronic TAM dosing scaled to be equivalent to the daily human dose. In the uteri, livers and brains from the patas (n = 3), and endometrium from the macaques (n = 4), TAM–DNA adducts were measurable by TAM–DNA chemiluminescence immunoassay. Average TAM–DNA adduct values for the patas uteri (23 adducts/108 nucleotides) were similar to those found in endometrium of the macaques (19 adducts/108 nucleotides). Endometrium of macaques exposed to both TAM and low-dose estradiol (n = 5) averaged 34 adducts/108 nucleotides. To examine TAM–DNA persistence in the patas, females (n = 3) were exposed to TAM for 3 months and to no drug for an additional month, resulting in low or non-detectable TAM–DNA in livers and uteri. Human endometrial and myometrial samples from women receiving (n = 8) and not receiving (n = 8) TAM therapy were also evaluated. Women receiving TAM therapy averaged 10.3 TAM–DNA adducts/108 nucleotides, whereas unexposed women showed no detectable TAM–DNA. The data indicate that genotoxicity, in addition to estrogen agonist effects, may contribute to TAM-induced human endometrial cancer.
    Carcinogenesis 02/2014; 35(5). DOI:10.1093/carcin/bgu029 · 5.33 Impact Factor
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    ABSTRACT: Cardiac troponins serve as serum biomarkers of myocardial injury. The current study examined the influence of age on serum concentrations of cardiac troponin I (cTnI). An ultrasensitive immunoassay was used to monitor cTnI concentrations in Sprague-Dawley (SD) rats and Erythrocebus patas monkeys of different ages. The mean cTnI concentrations were highest in 10-day-old rats compared to 25-, 40-, and 80-day-old SD rats. Cardiomyocyte remodeling was apparent in hearts from 10-day-old SD rats as evident by hypercellularity, irregularly shaped nuclei, and moderate numbers of myocytes undergoing mitosis and apoptosis. The mean concentration of cTnI in 5 newborn monkeys was considerably higher than that of three 1-year-old monkeys. Evidence of cardiomyocyte remodeling was also observed in these newborn hearts (loss of myofibrils and cytoplasmic vacuolation). Commercial animal serum samples were also analyzed. The concentrations of cTnI detected in fetal equine and porcine serum were considerably higher than that found in adult equine and porcine serum samples Likewise, fetal bovine serum had higher cTnI concentrations (>2,400 pg/ml) than did adult caprine and laprine samples (2.5-2.7 pg/ml). The present study found age-related differences in cTnI concentrations, with higher levels occurring at younger ages. This effect was consistent across several animal species.
    Toxicologic Pathology 10/2013; 42(5). DOI:10.1177/0192623313505154 · 2.14 Impact Factor

  • Cancer Research 08/2013; 73(8 Supplement):5367-5367. DOI:10.1158/1538-7445.AM2013-5367 · 9.33 Impact Factor
  • Andrea V. Rivera · Vanesa C. Sanchez · Miriam C. Poirier · Ofelia A. Olivero ·

    Cancer Research 08/2013; 73(8 Supplement):3603-3603. DOI:10.1158/1538-7445.AM2013-3603 · 9.33 Impact Factor
  • Eunwoo Shim · Daniel Liu · Alexander Gibbons · Miriam C. Poirier · Yongmin Liu ·

    Cancer Research 08/2013; 73(8 Supplement):4418-4418. DOI:10.1158/1538-7445.AM2013-4418 · 9.33 Impact Factor
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    ABSTRACT: Background: Erythrocebus patas (patas) monkeys were used to model antiretroviral (ARV) drug in human immunodeficiency virus type 1-infected pregnant women. Methods: Pregnant patas dams were given human-equivalent doses of ARVs daily during 50% of gestation. Mesenchymal cells, cultured from bone marrow of patas offspring obtained at birth and at 1 and 3 years of age, were examined for genotoxicity, including centrosomal amplification, micronuclei, and micronuclei containing whole chromosomes. Results: Compared with controls, statistically significant increases (P < .05) in centrosomal amplification, micronuclei, and micronuclei containing whole chromosomes were found in mesenchymal cells from most groups of offspring at the 3 time points. Conclusions: Transplacental nucleoside reverse-transcriptase inhibitor exposures induced fetal genotoxicity that was persistent for 3 years.
    The Journal of Infectious Diseases 04/2013; 208(2). DOI:10.1093/infdis/jit146 · 6.00 Impact Factor
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    ABSTRACT: Tamoxifen (TAM) is a selective estrogen receptor modulator used worldwide for adjuvant therapy and chemoprevention of breast cancer. Women receiving TAM have an increased risk of endometrial and myometrial cancer, which may be due to genotoxicity and/or receptor-related mechanisms. Controversy has surrounded the issue of whether or not TAM-DNA adducts form in humans, and we have examined this question in uterine tissues of aging Erythrocebus patas (patas) and Macaca fascicularis (macaque) monkeys given oral TAM dosing, as well as in endometrial and myometrial samples from women given TAM therapy. DNA adducts were determined by TAM-DNA chemiluminescence immunoassay (CIA) using an antiserum elicited against DNA modified with (E)-α-(deoxyguanosin-N2-yl)-tamoxifen (dG-TAM). Of 5 female patas, 2 were unexposed and 3 were given oral dosing with 1.7 mgTAM/kg bw/day for 3 months. Macaques were either exposed for 4 months with 1.3 mg TAM/kg bw/day (n=4) or unexposed (n=6). Normal and tumor uterine samples from women who received 20 mg/day (n=8) were analyzed along with samples (n=8) from unexposed women. We found 35.1±11.7 adducts /108nucleotides in the patas monkeys, 17±3.6 adducts /108nucleotides in the macaques, and 3.2-16.5 adducts /108 nucleotides in the women. None of the tissues from unexposed monkeys or women showed evidence of TAM-DNA adduct formation. Whatever the role played by TAM-DNA adduct formation in human endometrial cancer, these data demonstrate that TAM-DNA adducts are formed in monkey uterus as well as human endometrium, myometrium and endometrial tumor.
    2012 Society for Advancement of Hispanics/Chicanos and Native Americans in Science National Conference; 10/2012

  • Mitochondrion 09/2012; 12(5):557–558. DOI:10.1016/j.mito.2012.07.021 · 3.25 Impact Factor
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    ABSTRACT: We have evaluated DNA damage (DNA adduct formation) after feeding benzo[a]pyrene (BP) to wild-type (WT) and cancer-susceptible Xpa(−/−)p53(+/−) mice deficient in nucleotide excision repair and haploinsufficient for the tumor suppressor p53. DNA damage was evaluated by high-performance liquid chromatography/electrospray ionization tandem mass spectrometry (HPLC/ES-MS/MS), which measures r7,t8,t9-trihydroxy-c-10-(N 2-deoxyguanosyl)-7,8,9,10-tetrahydrobenzo[a]pyrene (BPdG), and a chemiluminescence immunoassay (CIA), using anti-r7,t8-dihydroxy-t-9,10-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (BPDE)–DNA antiserum, which measures both BPdG and the other stable BP-DNA adducts. When mice were fed 100 ppm BP for 28 days, BP-induced DNA damage measured in esophagus, liver and lung was typically higher in Xpa(−/−)p53(+/−) mice, compared with WT mice. This result is consistent with the previously observed tumor susceptibility of Xpa(−/−)p53(+/−) mice. BPdG, the major DNA adduct associated with tumorigenicity, was the primary DNA adduct formed in esophagus (a target tissue in the mouse), whereas total BP-DNA adducts predominated in higher levels in the liver (a non-target tissue in the mouse). In an attempt to lower BP-induced DNA damage, we fed the WT and Xpa(−/−)p53(+/−) mice 0.3% chlorophyllin (CHL) in the BP-containing diet for 28 days. The addition of CHL resulted in an increase of BP–DNA adducts in esophagus, liver and lung of WT mice, a lowering of BPdG in esophagi of WT mice and livers of Xpa(−/−)p53(+/−) mice and an increase of BPdG in livers of WT mice. Therefore, the addition of CHL to a BP-containing diet showed a lack of consistent chemoprotective effect, indicating that oral CHL administration may not reduce PAH–DNA adduct levels consistently in human organs.
    Carcinogenesis 07/2012; 33(11). DOI:10.1093/carcin/bgs247 · 5.33 Impact Factor
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    ABSTRACT: Benzo[a]pyrene (BaP) is a widespread environmental carcinogen activated by cytochrome P450 (P450) enzymes. In Hepatic P450 Reductase Null (HRN) and Reductase Conditional Null (RCN) mice, P450 oxidoreductase (Por) is deleted specifically in hepatocytes, resulting in the loss of essentially all hepatic P450 function. Treatment of HRN mice with a single i.p. or oral dose of BaP (12.5 or 125mg/kg body weight) resulted in higher DNA adduct levels in liver (up to 10-fold) than in wild-type (WT) mice, indicating that hepatic P450s appear to be more important for BaP detoxification in vivo. Similar results were obtained in RCN mice. We tested whether differences between hepatocytes and non-hepatocytes in P450 activity may underlie the increased liver BaP-DNA binding in HRN mice. Cellular localisation by immunohistochemistry of BaP-DNA adducts showed that HRN mice have ample capacity for formation of BaP-DNA adducts in liver, indicating that the metabolic process does not result in the generation of a reactive species different from that formed in WT mice. However, increased protein expression of cytochrome b(5) in hepatic microsomes of HRN relative to WT mice suggests that cytochrome b(5) may modulate the P450-mediated bioactivation of BaP in HRN mice, partially substituting the function of Por.
    Toxicology Letters 06/2012; 213(2):160-6. DOI:10.1016/j.toxlet.2012.06.016 · 3.26 Impact Factor
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    ABSTRACT: We have developed and validated a sandwich chemiluminescence immunoassay (SCIA) which measures polycyclic aromatic hydrocarbon (PAH)-DNA adducts combining high throughput and adequate sensitivity, appropriate for evaluation of adduct levels in human population studies. Fragmented DNA is incubated with rabbit antiserum elicited against DNA modified with r7,t8-dihydroxy-t-9,10-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (BPDE) and subsequently trapped by goat anti-rabbit IgG bound to a solid surface. Anti-single-stranded (ss) DNA antibodies binds in a quantity proportional to the adduct levels and is detected by chemiluminescence. The BPDE-DNA SCIA has a limit of detection of 3 adducts per 10(9) nucleotides with 5 μg DNA per well. We have validated the BPDE-DNA SCIA using DNA modified in vitro, DNA from benzo[a]pyrene (BP)-exposed cultured cells and mice. The levels of adduct measured by SCIA were lower (30-60%) than levels of bulky DNA adducts measured in the same samples by (32)P-postlabelling. The BPDE-DNA SCIA also detected adducts produced in vivo by PAHs other than BP. When blood DNA samples from maternal/infant pairs were assayed by BPDE-DNA SCIA, the adduct levels obtained were significantly correlated. However, there was no correlation between (32)P-postlabelling and SCIA values for the same samples. The SCIA can be extended to any DNA adduct and is expected to provide, when fully automated, a valuable high-throughput approach in large-scale population studies.
    Mutagenesis 05/2012; 27(5):589-97. DOI:10.1093/mutage/ges024 · 2.79 Impact Factor

Publication Stats

5k Citations
827.21 Total Impact Points


  • 1992-2014
    • National Institutes of Health
      • • Laboratory of Cancer Biology and Genetics
      • • Center for Cancer Research
      • • Branch of Cancer Etiology
      베서스다, Maryland, United States
  • 1986-2014
    • NCI-Frederick
      Фредерик, Maryland, United States
  • 1980-2014
    • National Cancer Institute (USA)
      • • Center for Cancer Research
      • • Laboratory of Cancer Biology and Genetics
      • • Laboratory of Human Carcinogenesis
      • • Laboratory of Experimental Immunology
      베서스다, Maryland, United States
  • 2008-2013
    • Council for Chemical Research
      베서스다, Maryland, United States
    • National Hellenic Research Foundation
      • Institute of Biology, Medicinal Chemistry and Biotechnology
      Athínai, Attica, Greece
  • 2010
    • National Institute of Allergy and Infectious Disease
      Maryland, United States
  • 1994-2010
    • Northern Inyo Hospital
      BIH, California, United States
    • Montefiore Medical Center
      New York City, New York, United States
  • 2009
    • Uniformed Services University of the Health Sciences
      • Department of Medicine
      Maryland, United States
  • 2005
    • National Institute of Occupational Health
      Amadavad, Gujarat, India
  • 2004
    • National Cancer Institute Ukraine
      Kievo, Kyiv City, Ukraine
    • National Heart, Lung, and Blood Institute
      Maryland, United States
  • 2003
    • Stony Brook University
      • Department of Pharmacological Sciences
      Stony Brook, NY, United States
  • 1993
    • Università degli Studi di Bari Aldo Moro
      Bari, Apulia, Italy
  • 1987
    • University of Oslo
      Kristiania (historical), Oslo, Norway