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Helmut Bartsch

Publications and source records attributed to Helmut Bartsch.

At least 37 records · Page 2Linked to original sources
PubMed2004

Immunohistochemical detection of 1,N6-ethenodeoxyadenosine in nuclei of human liver affected by diseases predisposing to hepato-carcinogenesis.

Increased oxidative stress and lipid peroxidation (LPO) are implicated in multistage carcinogenesis. Recent studies have shown that LPO-derived reactive hydroxyalkenals can form promutagenic exocyclic etheno-DNA adducts in vivo. Such DNA damage was found to be increased in the liver of patients with metal storage diseases and in colon adenomas of familial adenomatous polyposis patients. We now have investigated the levels of 1,N(6)-ethenodeoxyadenosine (epsilon dA) in human liver samples obtained from a group of patients diagnosed with hepatitis, fatty liver, fibrosis and cirrhosis, primary hemochromatosis and Wilson's disease. Using an immunohistochemical method, the relative mean pixel intensity of randomly selected nuclei was measured by imaging software; positively stained cell nuclei (arbitrary mean pixel intensity > or =0.5) were counted. Prevalence of epsilon dA (%) was calculated from the ratio of a number of positively stained cell nuclei over a total number of cells counted. When compared with normal livers (3.1%), the percent prevalence (means) was significantly higher in specimens of alcoholic fatty liver (15%) and fibrosis patients (50%) but not in samples with hepatitis (induced by various factors) (6.2%). The percent prevalence in alcohol fibrosis was as high as in the liver from Wilson's disease (50.7%) and hemochromatosis (33%) patients. This is the first demonstration of increased epsilon dA in human liver diseases due to alcohol abuse. We conclude that excessive hepatic DNA damage, as assessed by miscoding etheno-DNA adduct in the nuclei of liver biopsies, is probably caused by alcohol-induced oxidative stress and LPO. In cancer-prone liver diseases (fatty liver, cirrhosis/fibrosis) such damage may act as a driving force towards malignancy.

Adolescent↗
PubMed2004

Oxidative stress and lipid peroxidation-derived DNA-lesions in inflammation driven carcinogenesis.

UNLABELLED: During chronic inflammatory processes an excess of free radicals and DNA-reactive aldehydes from lipid peroxidation (LPO) are produced, which deregulate cellular homeostasis and can drive normal cells to malignancy. Etheno (epsilon)-modified DNA bases are generated by reactions of DNA with a major LPO product, trans-4-hydroxy-2-nonenal. We investigated steady state levels of epsilon-DNA adducts in organs, blood or urine from patients with cancer prone diseases, especially when related to persistent inflammatory processes. We have developed sensitive and specific methods for adduct detection in vivo. Hepatic etheno-adduct levels were significantly elevated in patients with Wilson's disease and primary hemochromatosis. Excess storage of copper/iron causing oxidative stress and LPO-derived DNA-damage, are implicated in disease pathogenesis as confirmed by studies in LEC-rats, a model for Wilson's disease. When patients with alcohol related hepatitis, fatty liver, fibrosis and cirrhosis were compared with asymptomatic livers, excess hepatic DNA-damage was seen in all patients, except those with hepatitis. Etheno-deoxyadenosine excreted in urine was measured in HBV-infected patients diagnosed with chronic hepatitis, cirrhosis and hepatocellular carcinoma: as compared to controls, patients had 20-90-fold increased urinary levels. IN CONCLUSION: epsilon-DNA adducts may serve as potential markers for assessing progression of inflammatory cancer-prone diseases. Also the efficacy of human chemopreventive interventions could be verified by using our non-invasive urine assay. Mechanisms and host-factors that influence the steady-state levels of epsilon-DNA adducts in cancer prone tissues are under investigation.

Animals↗
PubMed2004

A modified immuno-enriched 32P-postlabeling method for analyzing the malondialdehyde-deoxyguanosine adduct, 3-(2-deoxy-beta-D-erythro-pentofuranosyl)- pyrimido[1,2-alpha]purin-10(3H)one in human tissue samples.

The malondialdehyde-modified DNA adduct, 3-(2-deoxy-beta-d-erythro-pentofuranosyl)pyrimido[1,2-alpha]purin-10(3H)one (M1dG) has been detected in human tissues and is considered to be a promising biomarker for estimating lipid peroxidation-induced DNA damage. With the aim to analyze the M1dG in small amounts of DNA (<10 microg) and to improve the sensitivity, we have developed an immuno-enriched 32P-postlabeling HPLC method. The main modifications included the following steps: (i) an optimization of the immunoenrichment conditions using a monoclonal antibody (MAb D 10A1), (ii) a single labeling step of the purified M1dG 3'-monophosphate to its 5'-monophosphate at pH 6.8, (iii) the addition of O4-ethylthymidine 3'-monophosphate as an internal standard, and (iv) a prepurification of the labeled adduct on a polyethyleneimine minicolumn before HPLC analysis. With this protocol, the percent recovery of M1dG was found to be approximately 70 +/- 20; the detection limit in biological samples was approximately 200 amol M1dG from 10 microg of DNA, corresponding to 6 adducts/10(9) nucleotides. In conclusion, our modified method shows a high sensitivity and specificity; when applied to human breast and liver tissue samples, background levels of the M1dG could be reproducibly detected. This ultrasensitive detection method is thus suitable for applications in human biomonitoring and molecular epidemiology studies.

Chromatography, Affinity↗
PubMed2004

Alert for an epidemic of oral cancer due to use of the betel quid substitutes gutkha and pan masala: a review of agents and causative mechanisms.

In south-east Asia, Taiwan and Papua New Guinea, smoking, alcohol consumption and chewing of betel quid with or without tobacco or areca nut with or without tobacco are the predominant causes of oral cancer. In most areas, betel quid consists of a mixture of areca nut, slaked lime, catechu and several condiments according to taste, wrapped in a betel leaf. Almost all habitual chewers use tobacco with or without the betel quid. In the last few decades, small, attractive and inexpensive sachets of betel quid substitutes have become widely available. Aggressively advertised and marketed, often claimed to be safer products, they are consumed by the very young and old alike, particularly in India, but also among migrant populations from these areas world wide. The product is basically a flavoured and sweetened dry mixture of areca nut, catechu and slaked lime with tobacco (gutkha) or without tobacco (pan masala). These products have been strongly implicated in the recent increase in the incidence of oral submucous fibrosis, especially in the very young, even after a short period of use. This precancerous lesion, which has a high rate of malignant transformation, is extremely debilitating and has no known cure. The use of tobacco with lime, betel quid with tobacco, betel quid without tobacco and areca nut have been classified as carcinogenic to humans. As gutkha and pan masala are mixtures of several of these ingredients, their carcinogenic affect can be surmised. We review evidence that strongly supports causative mechanisms for genotoxicity and carcinogenicity of these substitute products. Although some recent curbs have been put on the manufacture and sale of these products, urgent action is needed to permanently ban gutkha and pan masala, together with the other established oral cancer-causing tobacco products. Further, education to reduce or eliminate home-made preparations needs to be accelerated.

Areca↗
PubMed2004

Identification and functional characterization of the natural variant MRP3-Arg1297His of human multidrug resistance protein 3 (MRP3/ABCC3).

The human multidrug resistance protein 3 (MRP3, symbol ABCC3) is an ATP-binding cassette transporter that mediates the efflux of organic anions, including lipophilic substances conjugated with glucuronate, sulphate or glutathione, across the basolateral membrane of polarized cells (e.g. hepatocytes) into blood. Genetic variants of MRP3 may affect the transport of these substances out of cells. The aims of this study were: (i) to identify MRP3 polymorphisms; (ii) to functionally characterize one relatively frequent MRP3 polymorphism; and (iii) to establish whether MRP3 transports bilirubin glucuronosides. Exonic nucleotide variants in the ABCC3 gene were identified by single-strand conformation polymorphism analysis. The 3890G>A mutation, resulting in MRP3-ArgHis, was introduced into the ABCC3 cDNA which was stably transfected into MDCKII cells. For the functional characterization of MRP3-ArgHis in comparison with MRP3, ATP-dependent transport was analysed in isolated membrane vesicles. Two non-synonymous MRP3 variants were identified with an allele frequency of 0.003 for 1643T>A (MRP3-LeuGln) and 0.08 for 3890G>A (MRP3-ArgHis). Because of the high frequency of the 3890G>A mutation, and because of the close proximity of Arg to the second nucleotide-binding domain, we pursued the functional characterization of the MRP3-ArgHis polymorphic variant. MRP3-ArgHis was correctly localized to the basolateral membrane of polarized MDCKII cells. We identified monoglucuronosyl bilirubin, bisglucuronosyl bilirubin and leukotriene C4 as substrates for both MRP3 and MRP3-ArgHis. Dehydroepiandrosterone-3-sulphate and 17beta-glucuronosyl oestradiol were transported with similar kinetics by MRP3 and MRP3-ArgHis. This experimental setup provides a useful tool to analyse the functional consequences of polymorphic variants of MRP3.

Adenosine Triphosphate↗
PubMed2004

Association between the risk for lung adenocarcinoma and a (-4) G-to-A polymorphism in the XPA gene.

Polymorphisms of genes coding for DNA repair can affect lung cancer risk. A common single nucleotide (-4) G-to-A polymorphism was identified previously in the 5' untranslated region of the XPA gene. In a case-control study in European Caucasians, the influence of this polymorphism on primary lung cancer risk overall and according to histologic subtypes was investigated. Four hundred sixty-three lung cancer cases (including 204 adenocarcinoma and 212 squamous cell carcinoma) and 460 tumor-free hospital controls were investigated using PCR amplification and melting point analysis of sequence-specific hybridization probes. Odds ratios (OR) were calculated by multiple logistic regression analysis adjusting for age, gender, smoking habits, and occupational exposure and showed a slightly enhanced risk for all lung cancer cases as well as for squamous cell carcinoma and adenocarcinoma cases. Gene-environment interactions were analyzed with respect to smoking and occupational exposure. A nearly 3-fold increased risk for adenocarcinoma associated with the XPA AA genotype was observed for occupationally exposed individuals (OR, 2.95; 95% confidence interval, 1.42-6.14) and for heavy smokers (OR, 2.52; 95% confidence interval, 1.17-5.42). No genotype-dependent increase in OR was found for nonexposed individuals or those smoking <20 pack-years. The significant effect of the XPA polymorphism in heavy smokers and occupationally exposed individuals suggests an important gene-environment interaction for the XPA gene. The underlying mechanisms as to why AA homozygotes are predisposed to lung adenocarcinoma and which specific carcinogens are involved remains to be determined.

Adenocarcinoma↗
PubMed2003

Radiation-induced DNA damage and repair in lymphocytes from breast cancer patients and their correlation with acute skin reactions to radiotherapy.

PURPOSE: Repair of radiation-induced DNA damage plays a critical role for both the susceptibility of patients to side effects after radiotherapy and their subsequent cancer risk. The study objective was to evaluate whether DNA repair data determined in vitro are correlated with the occurrence of acute side effects during radiotherapy. METHODS AND MATERIALS: Breast cancer patients receiving radiation therapy after a breast-conserving surgery were recruited in a prospective epidemiologic study. As an indicator for clinical radiosensitivity, adverse reactions of the skin were recorded. Cryo-preserved lymphocytes from 113 study participants were gamma-irradiated with 5 Gy in vitro and analyzed using the alkaline comet assay. Reproducibility of the assay was determined by repeated analysis (n = 26) of cells from a healthy donor. A coefficient of variation of 0.3 was calculated. RESULTS: The various parameters determined to characterize the individual DNA repair capacity showed large differences between patients. Eleven patients were identified with considerably enhanced DNA damage induction, and 7 patients exhibited severely reduced DNA repair capacity after 15 and 30 min. Six patients were considered as clinically radiosensitive, indicated by moist desquamation of the skin after a total radiation dose of about 50 Gy. CONCLUSIONS: Using the alkaline comet assay as described here, breast cancer patients were identified showing abnormal cellular radiation effects, but this repair deficiency corresponded only at a very limited extent to the acute radiation sensitivity of the skin. Because impaired DNA repair could be involved in the development of late irradiation effects, individuals exhibiting severely reduced DNA repair capacity should be followed for the development of late clinical symptoms.

Acute Disease↗
PubMed2003

A critical evaluation of DNA adducts as biological markers for human exposure to polycyclic aromatic compounds.

The causative role of polycyclic aromatic hydrocarbons (PAH) in human carcinogenesis is undisputed. Measurements of PAH-DNA adduct levels in easily accessible white blood cells therefore represent useful early endpoints in exposure intervention or chemoprevention studies. The successful applicability of DNA adducts as early endpoints depends on several criteria: i. adduct levels in easily accessible surrogate tissues should reflect adduct levels in target-tissues, ii. toxicokinetics and the temporal relevance should be properly defined. iii. sources of interand intra-individual variability must be known and controllable, and finally iv. adduct analyses must have advantages as compared to other markers of PAHexposure. In general, higher DNA adduct levels or a higher proportion of subjects with detectable DNA adduct levels were found in exposed individuals as compared with nonexposed subjects, but saturation may occur at high exposures. Furthermore, DNA adduct levels varied according to changes in exposure, for example smoking cessation resulted in lower DNA adduct levels and adduct levels paralleled seasonal variations of air-pollution. Intraindividual variation during continuous exposure was low over a short period of time (weeks), but varied significantly when longer time periods (months) were investigated. Inter-individual variation is currently only partly explained by genetic polymorphisms in genes involved in PAH-metabolism and deserves further investigation. DNA adduct measurements may have three advantages over traditional exposure assessment: i. they can smooth the extreme variability in exposure which is typical for environmental toxicants and may integrate exposure over a longer period of time. Therefore, DNA adduct assessment may reduce the monitoring effort. ii. biological monitoring of DNA adducts accounts for all exposure routes. iii. DNA adducts may account for inter-individual differences in uptake, elimination, distribution, metabolism and repair amongst exposed individuals. In conclusion, there is now a sufficiently large scientific basis to justify the application of DNA adduct measurements as biomarkers in exposure assessment and intervention studies. Their use in risk-assessment, however, requires further investigation.

Animals↗
PubMed2003

Benzo[a]pyrene enhances lipid peroxidation induced DNA damage in aorta of apolipoprotein E knockout mice.

The genotoxic compound benzo[a]pyrene (B[a]P) enhances atherosclerotic plaque progression, possibly by inducing oxidative stress and subsequent lipid peroxidation (LPO). Since LPO plays a key role in atherosclerosis, stable LPO derived DNA modifications such as 1,N6-ethenodeoxy-adenosine (epsilondA) and 3,N4-ethenodeoxy-cytidine (epsilondC) may be useful biomarkers for in vivo oxidative stress. In this study, benzo[a]pyrene-diol-epoxide (BPDE)-DNA, epsilondA and epsilondC were determined by 32P-postlabelling in apolipoprotein E knockout (ApoE-KO) mice treated with 5mg/kg B[a]P by gavage. After 4 days, BPDE-DNA adduct levels were higher in aorta (10.8 +/- 1.4 adducts/10(8) nucleotides) than in lung (3.3 +/- 0.7, P < 0.05), which is a known target organ for B[a]P. Levels of epsilondA were higher in aorta of B[a]P-exposed animals than in unexposed controls (8.1 +/- 4.4 vs 3.4 +/- 2.1 adducts per 10(8) parent nucleotides, P < 0.05). On the other hand, epsilondC levels were not affected by B[a]P exposure. Serum low density lipoprotein (LDL) levels were lower in B[a]P-exposed mice than in controls (9.3 +/- 3.7 and 13.3 +/- 4.0mmol/l, respectively), whereas high density lipoprotein (HDL) levels were higher (1.4 +/- 1.6 and 0.4 +/- 0.3mmol/l, respectively). Consequently, a three-fold difference in the LDL/HDL ratio was observed (P = 0.001). epsilondA levels were positively related with plasma HDL concentrations (R = 0.68, P = 0.02), suggesting that the HDL mediated protection of the vessel wall against reactive lipid peroxides was reduced in B[a]P-exposed apoE-KO mice. Our observations show that direct as well as lipid peroxidation induced DNA damage is formed by B[a]P in aorta of apoE-KO mice, which may be involved in atherosclerotic plaque progression. This study further indicates that etheno-DNA adducts are useful biomarkers for in vivo oxidative stress in atherosclerosis.

7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide↗
PubMed2003

Laryngeal cancer risk in Caucasians is associated with alcohol and tobacco consumption but not modified by genetic polymorphisms in class I alcohol dehydrogenases ADH1B and ADH1C, and glutathione-S-transferases GSTM1 and GSTT1.

OBJECTIVE: Alcohol and tobacco consumption are recognized risk factors for upper aerodigestive tract tumours, however individual susceptibility to these environmental factors varies. As part of the Rhein-Neckar Larynx-case-control study, this study investigated the potential risk-modifying effect of genetic polymorphisms in enzymes involved in ethanol and tobacco carcinogen metabolism for laryngeal cancer in Germany. METHODS: Two hundred and forty-five cases and 251 population-based controls, matched by age and gender, were genotyped for genetic polymorphisms in ADH1B, ADH1C, GSTM1 and GSTT1, using genomic DNA isolated from peripheral lymphocytes and employing PCR and PCR/restriction fragment length polymorphism-based methods. RESULTS: Neither the putative risk genotypes ADH1B*2/*1 (OR 0.86, 95% confidence interval (CI): 0.41-1.82) or ADH1C*1/*1 (OR 1.06, CI 0.7-1.62) nor GSTM1 null (OR 0.94, CI 0.62-1.42) or GSTT1 null (OR 1.34, CI 0.74-2.42) were associated with an overall increased risk for laryngeal cancer. Stratified analyses were carried out to determine the gene-environment interaction in relation to laryngeal cancer risk. However, ADH1B or ADH1C genotypes did not markedly modify the risk observed after stratification by alcohol consumption, and stratification by cumulative smoking exposure (in packyears) did not show an association of GSTM1 or GSTT1 genotype with laryngeal carcinoma either. CONCLUSION: The lack of risk modification by the studied genotypes emphasizes the importance of environmental exposure to tobacco smoke and alcohol as major risk factors for laryngeal cancer in the German study population.

Alcohol Dehydrogenase↗
PubMed2003

The CYP3A4*1B allele increases risk for small cell lung cancer: effect of gender and smoking dose.

CYP3A isozymes are involved in tobacco carcinogen- and steroid-metabolism, and are expressed in human lung tissue showing interindividual variation in expression and activity. The CYP3A4*1B allele has been associated with a two-fold higher promoter activity and with high-grade prostate cancers. The very frequent intron 3 polymorphism in the CYP3A5 gene (CYP3A5*3) results in decreased CYP3A5 protein levels. A case-control study was conducted in 801 Caucasian lung cancer patients that included 330 adenocarcinomas, 260 squamous cell carcinomas, 171 small cell lung cancers (SCLC) and 432 Caucasian hospital-based controls. CYP3A-genotyping was performed by capillary polymerase chain reaction followed by fluorescence-based melting curve analysis. A significantly increased SCLC risk for CYP3A4*1B allele carriers [odds ratio (OR) 2.25, 95% confidence interval (CI) 1.11-4.55, P=0.02] was found. After dividing cases and controls by gender, an increased lung cancer risk for CYP3A4*1B carriers (OR 3.04, 95% CI 0.94-9.90, P=0.06) for women but not for men (OR 1.00, 95% CI 0.56-1.81) was revealed. Heavier smoking men (> or =20 pack-years) with the CYP3A4*1B allele had a significant OR for lung cancer of 3.42 (95% CI 1.65-7.14, P=0.001) compared to *1A/*1A carriers with lower tobacco exposure (<20 pack-years). For women, the respective OR was 8.00 (95% CI 2.12-30.30, P=0.005). Genotype frequencies were generally in Hardy-Weinberg equilibrium, except for CYP3A5 where a greater than expected number of CYP3A5*1 homozygotes was observed among cases (P=0.006). In addition, we observed linkage disequilibrium of CYP3A4 and CYP3A5 (P<0.00001), but a non-significantly increased lung cancer risk was only found for homozygous CYP3A5*1 allele carriers (OR 5.24, 95% CI 0.85-102.28, P=0.14) but not for heterozygotes. To confirm our observation that the CYP3A4*1B allele increases SCLC risk and modifies the smoking-related lung cancer risk in a gender-specific manner, further studies, including CYP3A haplotype analysis, will be necessary.

Adenocarcinoma↗
PubMed2002

Myeloperoxidase (MPO) genotype and lung cancer histologic types: the MPO -463 A allele is associated with reduced risk for small cell lung cancer in smokers.

MPO participates in the metabolic activation of tobacco carcinogens such as PAHs. A frequent MPO -463 G-->A polymorphism in the promoter region reduces MPO transcription and has been correlated with >4-fold lower benzo[a]pyrene-DNA adduct levels in the skin of coal tar-treated patients. Four of 7 case-control studies found significantly reduced lung cancer risk associated with the A allele. Due to their different etiologies, we examined whether the MPO genotype affects histologic lung cancer types differentially. A case-control study was conducted in 625 ever-smoking lung cancer patients, including 228 adenocarcinomas, 224 SCCs, 135 SCLCs and 340 ever-smoking hospital controls. MPO genotyping was performed by capillary PCR followed by fluorescence-based melting curve analysis. Combining the MPO -463 (G/A+A/A) genotypes, a protective effect approaching significance (OR = 0.75, 95% CI 0.55-1.01) was observed when comparing all lung cancer cases to controls. Among histologic types of lung cancer, a weak protective effect was found for both adenocarcinoma (OR = 0.81, CI 0.55-1.19) and SCC (OR = 0.82, CI 0.56-1.21); a stronger and significant effect was found for SCLC (OR = 0.58, CI 0.36-0.95; p = 0.029). Our results also suggest that the MPO genotype varies among inflammatory nonmalignant lung diseases. In conclusion, our results emphasize the need for a separate analysis of lung cancer histologic types and an adjustment for inflammatory nonmalignant lung diseases in future MPO-related studies. We confirm that the MPO -463 A variant affords a protective effect against lung cancer risk in smokers, which was strongest for SCLC patients.

Adenocarcinoma↗
PubMed2002

Urinary level of 1,N(6) -ethenodeoxyadenosine, a marker of oxidative stress, is associated with salt excretion and omega 6-polyunsaturated fatty acid intake in postmenopausal Japanese women.

Excretion of 1,N(6)-ethenodeoxyadenosine (epsilon dA), a marker for lipid peroxidation (LPO)-derived DNA damage was analyzed in urine of nonsmoking postmenopausal women participating in a dietary intervention trial in Northern Japan. Hereby the efficacy of dietary consultation in reducing salt and increasing vitamin C and carotenes during 1 year was estimated. Thirty postmenopausal women, 60-69 years of age, from the intervention group and 30 age-matched women from the control group were randomly selected. The subjects completed a self-administered diet history questionnaire and in the pre- and post-intervention period 48 hr urine and fasting blood samples were collected. epsilon dA in urine was analyzed by an immuno-precipitation-high performance liquid chromatography-fluorescence detection method. epsilon dA excretion (/48 hr) in the 59 postmenopausal Japanese women with complete urine collection ranged from 12-226 pmol at the pre-intervention. At the pre-intervention, epsilon dA excretion was positively associated with urinary salt excretion (R = 0.33, p = 0.01) and omega-6 polyunsaturated fatty acid intake (%energy value, R = 0.28, p = 0.03) in the 59 women. The average epsilon dA excretion in the intervention group was 61 pmol at pre-intervention and 44 pmol at post-intervention (p = 0.14). In the control group, it was 58 pmol at pre-intervention and 75 pmol at post-intervention (p = 0.24). During the intervention period, 18/29 (62%) of the subjects in the intervention group exhibited the decreased excretion and 10/26 (38%) in the control group (p = 0.08). Results from this pilot study suggest urinary epsilon dA as a potential biomarker of DNA damage possibly derived from salt-induced inflammation and LPO; further exploration of epsilon dA in human biomonitoring studies is warranted.

Aged↗
PubMed2002

Reduced poly(ADP-ribosyl)ation in lymphocytes of laryngeal cancer patients: results of a case-control study.

Poly(ADP-ribose) polymerase (PARP), a nuclear enzyme that is catalytically activated by DNA strand breaks, plays a complex role in DNA repair. Using NAD(+) as a precursor, it catalyzes the formation of ADP-ribose polymers, which are attached to various proteins. Defects in DNA repair pathways have been associated with increased risks for cancer in humans. We investigated whether differences in the activity of PARP are associated with the risk for laryngeal cancer. In a case-control study on genetic, lifestyle and occupational risk factors for laryngeal cancer, PARP activity was assessed as DNA damage-induced poly(ADP-ribose) formation in human peripheral blood lymphocytes by quantitative immunofluorescence analysis. Polymer formation was determined as the cellular response to bleomycin, a well-known inducer of DNA strand breaks, in lymphocytes from 69 laryngeal cancer patients and 125 healthy controls. The frequency of bleomycin-induced polymer formation, measured as mean pixel intensity, was significantly lower in cases (74.6, SE = 3.7) than in controls (94.5, SE = 3.5) and not influenced by smoking, age or sex. There was no significant difference between cases (59.1, SE = 5.2) and controls (50.5, SE = 3.7) in basal polymer formation (in cells not treated with bleomycin). When the highest tertile of polymer formation was used as the reference, the odds ratio for the lowest tertile of bleomycin-induced polymer formation was 3.79 (95% confidence interval 1.37-10.47, p = 0.01). Peripheral blood lymphocytes from laryngeal cancer patients thus showed significantly less bleomycin-induced poly(ADP-ribose) formation. Our results suggest that a reduced capacity of somatic cells to synthesize poly(ADP-ribose) might be associated with an increased risk for laryngeal cancer. The underlying mechanism remains to be investigated.

Adult↗