Genome-wide association studies have provided evidence that common variation at 5p15.33 [telomerase reverse transcriptase (TERT)-cleft lip and palate transmembrane 1-like (CLPTM1L)], 6p21.33 and 15q25.1 (CHRNA5-CHRNA3) influences lung cancer risk and cancer types with strong environmental risk factors. To independently validate these associations, we compared 5p15.33 (rs402710, rs401681), 6p21.33 (rs4324798) and 15q25.1 (rs1051730, rs16969968 and rs8034191) genotypes in 365 non-small cell lung cancer cases and 440 controls. Consistent with published data, variant genotypes of 5p15 (rs402710), 6p21 and 15q25 showed dose-dependent associations with lung cancer risk. To examine if variants influence the impact of environmental risk factors on lung carcinogenesis, we studied the relationship between genotype and levels of bulky aromatic/hydrophobic DNA adducts in lung tissue adjacent to tumor from 204 lung cancer cases. The risk allele of rs402710 (TERT-CLPTM1L locus) was associated with significantly higher levels of bulky aromatic/hydrophobic DNA adducts (P = 0.02). These data demonstrate a potential association between the TERT-CLPTM1L variant and levels of bulky DNA adducts measured by (32)P-postlabeling and hence a basis for susceptibility to the development of lung cancer.

Lung cancer is a leading cause of cancer mortality worldwide with smoking and occupational exposure to carcinogenic compounds as the major risk factors. Susceptibility to lung cancer is affected by existence of polymorphic genes controlling the levels of metabolic activation and detoxification of carcinogens. We have investigated 105 single nucleotide polymorphisms (SNPs) in 31 genes from the phase I and phase II metabolism genes and antioxidant defense genes for association with the risk of non-small cell lung cancer (NSCLC) in a Norwegian population-based study. Our results indicate that several SNPs in the phase I genes, CYP1B1, CYP2D6, CYP2E1 and CYP3A4, are associated with the risk of NSCLC. Moreover, significant associations with multiple SNPs in the phase II genes ALDH2, COMT, EPHX1, SOD2, NAT1, NAT2, GSTM3, GSTP1, GSTT2 and MPO were also found. We prioritized our findings by use of two different recently developed Bayesian statistical tools, employing conservative prior probabilities of association. When we corrected for multiple testing using these statistical tools, three novel associations of NSCLC risk with SNPs in the CYP1B1 (Arg48Gly), COMT (Val158Met) and GSTT2 (Met139Ile) genes were found noteworthy. However, only four of the previously reported associations with polymorphisms in the GSTP1 (Ala14Val), SOD2 (Val16Ala), EPHX1 (His139Arg) genes and the NAT1 fast acetylator phenotype remained significantly associated with lung cancer.

Mutations in the TP53 gene are important events during human lung carcinogenesis. The TP53 gene harbors several polymorphisms, and functional studies have shown that the Arg72Pro polymorphism alters both wild-type and mutant p53 protein activity. Thus, we hypothesized that certain Arg72Pro genotypes may influence the frequency and pattern of somatic mutations in TP53 . We therefore examined the status of the Arg72Pro polymorphism and TP53 mutations in 260 non–small-cell lung cancer cases. Here we report a significant trend toward lower frequency of TP53 mutations with increasing number of Pro72 alleles (P = 0.02). Overall, Pro72 allele carriers had significantly lower frequency of TP53 mutations compared with Arg72 homozygotes (P = 0.02). In addition, carriage of the Pro72 variant was related to a lower frequency of mutations affecting the hotspot codon 273. Mutations at codon 273 accounted for 10.6% of the mutations in Arg72 homozygotes and 1.7% of the mutations in Pro72 allele carriers. Our results suggest that the genotype of the Arg72Pro polymorphism may modulate the frequency of TP53 mutations in non– small-cell lung cancer. (Cancer Epidemiol Biomarkers Prev 2007;16(10):2077–81)

Background: The dopaminergic pathway may be of interest in assessing risk of non-small cell, lung cancer (NSCLC). Dopamine receptors are expressed in alveolar epithelial cells and human lung tumours, and dopamine inhibits both cell proliferation in vitro and growth of lung tumour xenografts in nude mice. Moreover, dopamine selectively inhibits the vascular permeability and angiogenic activity of vascular endothelial growth factor (VPF/VEGF). The bioavailability of dopamine is regulated by dopamine receptors D2 (DRD2), D4 (DRD4) and dopamine transporter 1 (DAT1/SLC6A3) genes.Methods: We have analysed 10 single nucleotide polymorphisms in DRD2, DRD4 and DAT1/SLC6A3 genes in relation to lung cancer risk in a case-control study of smoking subjects. The study subjects were 413 healthy individuals from general population and 335 NSCLC cases. Both cases and controls were Caucasians of Norwegian origin.Results: We demonstrate that DRD2 polymorphisms -141Cdel, 3208G > T, TaqIB; DRD4 -521C >T and DAT1/SLC6A3 -1476T > G are associated with a two- to five-fold increased NSCLC risk. The variant alleles of DRD2 1412A > G and 960C > G had protective effects.Conclusion: The dopamine receptor/transport gene polymorphisms are associated with the risk of NSCLC among smokers. The data show that the polymorphisms resulting in lower dopamine bioavailability were associated with increased risk of NSCLC. (c) 2006 Elsevier Ireland Ltd. All rights reserved.

5297 Studies have indicated that inflammation and reactive oxygen species induced by smoking, may play a role in lung cancer development. The aim of this study was to investigate whether germline sequence variants of the inflammatory genes Interleukin-1B (IL-1B), interleukin 1 receptor antagonist (IL1RN), interleukin-6 (IL6), interleukin-8 (IL8), cyclooxygenase-2 (COX2/PTGS2), and the anti-inflammatory nuclear transcription factor PPARG act as common, low-penetrance alleles for susceptibility to lung cancer. In a case-control study, comprising of 523 individuals of Norwegian origin, the relative risk of lung cancer associated with allelic variants of these genes (SNPs) was determined using the TaqMan methodology. Here we report that carriers of IL-1B-31 (T/T) and IL-1B-511 (C/C) had increased risk of lung cancer with odds ratio of 2.39 (95% CI, 1.29-4.44) for –31T/T and 2.51 (95% CI, 1.47-4.58) for –511C/C genotypes. This risk was further increased by presence of an IL1RN-1 allele in combination with IL-1B T/T, odds ratio 5.7 (95% CI, 2.1-15.7) or IL-1B C/C; odds ratio 6.3 (95% CI, 2.3-17.1), respectively. Interestingly, the risk was completely abolished by presence of an IL1RN-2 allele in these subjects. In view of the significance of the p53 gene in lung carcinogenesis, we also analysed the IL1B genotypes in relation to p53 mutations in the tumors. The results indicated that subjects having homozygote genotypes were more likely to have a mutation in the p53 gene (P = 0.05). We also found that carriers of the C allele of a polymorphism in the 3’ UTR region of the COX2 gene had a significantly increased risk of lung cancer, with odds ratios of 4.28 (95% CI: 2.44-7.49) for homozygotes and 2.12 (95% CI: 1.25-3.59) for heterozygotes. It was also found that an IL6 promoter polymorphism was associated with increased risk of squamous cell carcinoma. In conclusion, we have demonstrated that polymorphisms in inflammatory genes may be associated with risk of lung cancer.

Objective: Cytochrome P450 1A1 plays a major role in the bioactivation of a number of tobacco procarcinogens. Much interest has focused on a polymorphism in exon 7 of the CYP1A1 gene which has been associated with a more inducible form of the enzyme. However, past results of its association with lung cancer have been inconsistent, especially in Caucasians. We carried out a pooled analysis of the data submitted to the Genetic Susceptibility to Environmental Carcinogens (GSEC) database to further investigate this association and, especially, to examine the modifying effects of smoking status and race. Methods: The data set used in this analysis included 11 studies and a total of 1950 cases and 2617 controls. Both fixed- and random-effects, meta-analysis models were used to investigate heterogeneity among studies. Because no clear heterogeneity was found, a pooled analysis was conducted using unconditional logistic regression. Results: The pooled odds ratio for subjects heterozygous and homozygous for the exon 7 polymorphism was 1.15 (95% confidence interval: 0.95–1.39) and 1.54 (95% CI: 0.97–1.46), respectively (p for gene-dosage effect: 0.03). This association was stronger for squamous cell carcinoma (SCC) than adenocarcinoma, and appeared to be stronger in Caucasians than Asians (p for interaction: 0.03). Statistically significant interactions were also detected for smoking status and sex, with the effect of the polymorphism being stronger in never-smokers and in females. Conclusions: The present data suggest that the CYP1A1 exon 7 polymorphism may confer an increased risk of lung cancer, particularly of SCC, and especially in never-smokers and in women. These interactions need to be confirmed when additional studies are available for pooling.

The prognostic value ofp53status in non-small cell lung cancer has been investigated in 148 patients with clinical stage I-IIIB disease. Tumor tissues were examined for mutations in exons 4–9, with emphasis on defined structural and functional domains. Eighty-four mutations were detected in 83 (54%) of the patients. Eighty-eight percent of the mutations were within exons 5–8, and 12% of the mutations were within exons 4 and 9. Missense mutations occurred in 67% of the tumors, and 30% were null mutations (10% stop mutations, 15% frameshift mutations, and 5% splice site mutations). Patients with mutations inp53 had a significantly higher risk for lung cancer-related death and for death from all causes than those with wild-type p53 [hazard ratio (HR) 5 2.09 and 95% confidence interval (CI) 5 1.20–3.64 and HR5 1.69 and 95% CI 5 1.06–2.70, respectively]. Mutations in p53 related to even still poorer lung cancer-related prognosis were found at the following locations: (a) exon 8 (HR5 3.5; 95% CI, 1.59–7.71)]; (b) the structural domains L2 1 L3 (HR 5 2.36; 95% CI, 1.18– 4.74), and (c) codons involved in zinc binding (HR5 11.7; 95% CI, 3.56–38.69). Together, the biologically functional group of severe flexible mutants (codons 172, 173, 175, 176, 179, 181, 238, 245, and 267) and severe contact mutants (248, 282) were significantly related to shorter lung cancer-related survival (HR 5 4.16; 95% CI, 1.93–8.97). Squamous cell carcinoma was the dominant histological type in tumors involved in poor prognosis in exon 8 (HR5 3.19; 95% CI, 1.07–9.45). These results indicate that mutations in defined structural and functional domains of p53 may be useful molecular biological markers for prognosis and treatment strategy in non-small cell lung cancer patients.

In this study of 221 lung cancer patients and 212 controls, no association between a Msp I polymorphism in the CYP1A1 gene and an increased risk of lung cancer was found. Histological type, smoking habits and family history were also examined. No associations between the Msp I restriction fragment length polymorphism in the CYP1A1 gene and any of these parameters were found. These results are in contrast to a previous report by a Japanese group (Kawajiri et al., 1990) who found an association between the less common allele and an increased susceptibility to lung cancer in their population. The frequency of the less common Msp I 1.9 kb fragment allele (C2) appears to be three times greater in the Japanese population than in the Norwegian population and a Caucasian population of North America. It is possible that in the Asian population this Msp I polymorphism is in linkage disequilibrium with another mutation important for CYP1A1 gene expression, whereas in the Caucasian population these mutations are in equilibrium

We have examined DNA restriction fragment length polymorphisms (RFLP) of the Ha-ras-1 gene in DNA from 118 lung cancer patients and 123 unaffected controls. When DNA samples were digested with MspI/ HpaII restriction endonucleases. Southern blot analysis demonstrated 4 common, 4 intermediate and 7 different rare alleles in the combined population after hybridization to the pGDa1 probe. Six of the rare alleles were unique for the lung cancer group and 1 rare allele for the control group. The frequency of rare alleles in lung cancer patients (10/236) was significantly different (P<0.01) from the control group (1/246). The lung cancer group also had a significantly lower frequency of the common 2.57 kb fragment than the controls (P<0.02). The results thus indicate that Ha-ras genotyping may be of value in lung cancer risk assessment.

The oxygen consumption of isolated rat heart mitochondria was potently depressed in presence of 10-50 microM Na2CrO4 when NAD-linked substrates were oxidized. The succinate stimulated respiration and the oxidation of exogeneous NADH in sonicated mitochondria were not affected by chromate at this concentration range. A rapid and persistent drop (40% in 2 min) in the mitochondrial NADH level was observed after chromate addition (30 microM) under conditions which generally should promote regeneration of NADH. Experiments with bis-(2-ethyl-2-hydroxybutyrato)oxochromate(V) and vanadyl induced reduction of Cr(VI) in presence of excess NADH were performed. These experiments indicated that NADH may be directly oxidized by Cr(V) at physiological pH. The activity of 10 different enzymes were measured after lysis of intact mitochondria pretreated with chromate (1-100 microM). Na2CrO4 at a very low level (3-5 microM) was sufficient for 50% inhibition of alpha-ketoglutarate dehydrogenase. Higher concentrations (20-70 microM) was necessary for similar effect on beta-hydroxybutyrate and pyruvate dehydrogenase. The other enzymes tested were unaffected. Thus, the chromate toxicity in mitochondria may be due to NADH depletion as a result of direct oxidation by Cr(V) as well as reduced formation of NADH due to specific enzyme inhibition.

Nickel is a toxic metal of environmental concern that has been found to be carcinogenic in man and animals. Primary human kidney (NHKE) cells were immortalized or rescued from senescence after exposure to NiSO4. The cell lines (IHKE) displayed abnormal karyotype and anchorage independent growth was observed. However, none of the IHKE cells produced tumor upon injection into athymic nude mice. Transfer of the v-Ha-ras oncogene into IHKE cells induced conversion of the immortalized cells into cell lines (THKE) that were tumorigenic when transplanted into athymic nude mice. Ha-ras DNA was present in the transformed cell lines and expressed at high level.

The reduction of hexavalent chromium (Cr(VI)) by rat liver microsomes was studied. With 15–120 μM Na2CrO4 microsomes (0.5 mg protein/ml) effectively reduced Cr(VI) in the presence of NADPH provided anaerobic conditions. Phenobarbital (PB) and Aroclor 1254 (PCB) pretreatment increased microsomal Cr(VI) reduction while CoCl2 reduced the rate. The rates with 30 μM Na2CrO4 were: 6.4±0.1, 7.8±0.7, 13.4±0.5, 2.95±0.09 nmol Cr·mg prot.−1min−1 for control, PB, PCB and cobalt pretreated microsomes respectively. Kinetic studies gave a Michaeli-Menten like first-order kinetics with increases both in Km and Vmax values after pretreatment with PB or PCB. CO partly inhibited the microsomal Cr(VI) reduction. The CO-sensitive reduction rate was directly correlated to the cyt. P-450 content of the different microsomal preparations. Substituting NADH for NADPH gave approximately 27% lower activity with 30 μM Na2CrO4. This activity was neither inducible by cyt. P-450 inducers nor influenced by CO. Oxygen 1.0% and 0.10% gave approximately 100% and 30% inhibition of Cr(VI) reduction (30 μM Na2CrO4) respectively, and an uncompetitive like inhibitory pattern was found. No redox cycling of Cr(VI) was seen. 51Cr binding to the microsomes was approximately 10% after complete reduction of 30 μM Na2CrO4. Externally added FMN, Fe3+-ADP and nitrobenzen stimulated microsomal Cr(VI) reduction. A 60% higher reduction rate of Cr(VI) by isolated hepatocytes was found during aneorobic in comparison with aerobic conditions.

Acta Pharmacologica et ToxicologicaVolume 59, Issue s7 p. 624-626 PROBLEMS WITH METHODS FOR MEASUREMENT OF HEXAVALENT CHROMIUM APPLIED TO BIOLOGICAL SAMPLES. David Ryberg, David Ryberg Institute of Occupational Health, Oslo Norway.Search for more papers by this author David Ryberg, David Ryberg Institute of Occupational Health, Oslo Norway.Search for more papers by this author First published: December 1986 https://doi.org/10.1111/j.1600-0773.1986.tb02842.xCitations: 3AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article.Citing Literature Volume59, Issues7December 1986Pages 624-626 RelatedInformation

Acta Pharmacologica et ToxicologicaVolume 59, Issue s7 p. 267-269 MICROSOMAL REDUCTION OF Cr VI J. Alexander, J. Alexander Department of Toxicology, National Institute of Public Health, Oslo, P Norway.Search for more papers by this authorA. Mikalsen, A. Mikalsen Department of Toxicology, National Institute of Public Health, Oslo, P Norway.Search for more papers by this authorD. Ryberg, D. Ryberg Institute of Occupational Health, Oslo, Norway. Department of Toxicology, National Institute of Public Health, Oslo, P Norway.Search for more papers by this author J. Alexander, J. Alexander Department of Toxicology, National Institute of Public Health, Oslo, P Norway.Search for more papers by this authorA. Mikalsen, A. Mikalsen Department of Toxicology, National Institute of Public Health, Oslo, P Norway.Search for more papers by this authorD. Ryberg, D. Ryberg Institute of Occupational Health, Oslo, Norway. Department of Toxicology, National Institute of Public Health, Oslo, P Norway.Search for more papers by this author First published: December 1986 https://doi.org/10.1111/j.1600-0773.1986.tb02759.xCitations: 2AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article.Citing Literature Volume59, Issues7December 1986Pages 267-269 RelatedInformation

The reduction of hexavalent chromium (Cr(VI)) in isolated liver mitochondria was studied under different redox conditions in the respiratory chain. With 25 μM Na2CrO4 the rates were 1.6 ± 0.7, 13.9 ± 0.6 and 12.7 ± 0.7 nmole Cr(VI) reduced 15 min/mg protein with the electron transport chain oxidized, reduced and only complex 1 reduced respectively. Electrons from succinate, bypassing complex 1, were apparently unavailable for Cr(VI)-reduction. The kinetics of chromate reduction was studied with only complex 1 in a reduced state. A rapid and a slow phase were found, probably corresponding to different electron donors in the mitochondria. Blocking the free thiols with N-ethylmaleimide lead to less than 10% decrease in the rapid initial Cr(VI)-reduction and to about 20% decrease during the whole incubation period (15 min). The amounts of free thiols were moderately decreased (15%) in chromate treated mitochondria during the slow reduction of Cr(VI) only. SH-groups may thus participate as reductants during the slow reduction phase. The respiration rate was inhibited about 50% by 25 μM Na2CrO4 when the mitochondria oxidized NAD-linked substrates. In contrast, succinate stimulated respiration was inhibited 50% by 3.6 mM Na2CrO4. The observed inhibition with Na2CrO4 in the micromolar range was therefore probably localized at complex 1 and may be coupled to the reduction of Cr(VI) at the same place. The respiration of isolated hepatocytes was also affected by Na2CrO4. Five micromolar chromate caused 5–10% inhibition. The inhibitory action of chromate on the mitochondrial respiration may thus constitute an important cytotoxic mechanism.