Biomedical subjects

V Habalová

Publications and source records attributed to V Habalová.

7 recordsLinked to original sources

PubMed2005

A pilot study testing the genetic polymorphism of N-acetyltransferase 2 as a risk factor in lung cancer.

NAT2 as phase II enzyme is involved in the detoxification/activation of various drugs, environmental substances and carcinogenic compounds. A genotyping approach has been used to investigate NAT2 genotype with putative relevance in lung cancer in population of 110 Slovak-Caucasians patients and 167 non-malignant individuals from the same region. Slow acetylation was not observed to be a significant risk factor of lung cancer development (OR=1.19; 95% CI: 0.71-1.99). However, one genotype responsible for slow acetylation (NAT2*5B/*6) was observed significantly more frequently in lung cancer patients with squamous cell carcinoma compared with control subjects (OR=2.24; 95% CI: 1.14-4.34). Stratified analysis showed an increasing impact of the specific allelic combination NAT2*5B/*6 in non-smokers (OR=6.5; 95% CI: 1.25-15.08). In the case of squamous lung carcinoma an analysis revealed a tendency to adversely affect cancer risk in the individuals with the mentioned genotype in younger than 60 years (OR=3.14; 95% CI: 0.98-9.72) non-smokers (OR=10.40; 95% CI: 1.35-118.89) and in females (OR=4.25; 1.08-16.25). Additional studies are needed to confirm the results we observed and to assess the impact of other effects (specific allelic combinations, sex differences and histological subtype of lung cancer) on NAT2 susceptibility in lung carcinogenesis.

Acetylation↗

PubMed2004

Combined analysis of polymorphisms in glutathione S-transferase M1 and microsomal epoxide hydrolase in lung cancer patients.

Many genes involved in the metabolism of carcinogens have been found to be polymorphic in the human population, and specific alleles are associated with increased risk of cancer at various sites. The etiology of most commonly occurring cancers cannot be explained by allelic variability at a single locus. A combined analysis of two polymorphic enzymes, glutathione S-transferase M1 (GSTM1), microsomal epoxide hydrolase (EPHX1)) and their implication as lung cancer risk factors was performed in a case- control study of non small cell lung cancer. Polymerase chain reaction (PCR) or PCR-RFLP-based methods were used to detect variant genotypes of GSTM1 and EPHX1 (113Tyr-113His in exon 3 and 139His-139Arg in exon 4) in 150 controls and group of lung cancer patients (n=121). The slow 113His EPHX1 allele tended to be more frequent among the patients (frequency 0.587) than among the controls (0.320) (Fisher s exact test, p=0.33). The combined EPHX1 homozygote genotype His113/His139 (predicted very slow activity) versus all other genotype combination was associated with an increased risk of lung cancer (OR=2.29; 95% C.I.=0.94- 5.82), particularly in non-smokers (OR=11.23; 95% C.I.=1.48- 88.41). Polymorphism in GSTM1 had no statistically significant impact on lung cancer risk alone (OR=1.09; 95% C.I.: 0.65-1.82). However, obtained the results revealed that combinations GSTM1 null with homozygote His113/His139 genotype (predicted very slow activity EPHX1) significantly increased lung cancer risk (OR=3.65; 95% C.I.: 1.04-16.07). No overall relationship between genotype combinations predicted high EPHX1 activity and lung cancer risk was confirmed in all followed respects. However, the number of investigated individuals in our study was relatively small, therefore these findings should be judged with circumspectness.

Aged↗

PubMed2000

p53 single nucleotide polymorphisms and bladder cancer.

Two p53 germline polymorphisms, a BstUI in exon 4 and a MspI in intron 6 were studied using polymerase chain reaction (PCR) based methods in 50 patients with bladder cancer and 145 healthy controls. Increased frequencies of the BstUI and MspI A2 alleles were found to be associated with statistically non-significant (p = 0.2308 and p = 0.5959) but increased odd ratios for bladder cancer (OR 1.44, 95% CI 0.82-2.27 and OR 1.20, 95% CI 0.61-2.33). Statistically significant difference between patients with bladder cancer and controls was found in the distribution of MspI genotypes. There was a significantly lower proportion of the heterozygous A1A2 genotype in all patients but not in controls (p = 0.0354). The results of this study suggest that BstUI and Msp1 germ line polymorphisms of the tumor suppressor gene p53 marginally modify the risk of bladder cancer.

Deoxyribonuclease HpaII↗

PubMed1999

Reciprocal adaptive response of human peripheral lymphocytes induced by bleomycine or gamma rays.

The adaptive response and reciprocal adaptive response induced in vitro by exposure to low doses of gamma rays (0.05 Gy) or bleomycin (0.05 microg/ml) in human peripheral blood lymphocytes were assessed by the frequency of chromosome aberrations. Gamma rays (1.5 Gy) or bleomycin (1.5 microg/ml) were used as the challenge doses. In the experiments, blood samples from 5 healthy donors were investigated. It has been found that low doses of bleomycin and gamma rays induced a reciprocal adaptive response to high doses of gamma rays or bleomycin. Moreover, the results confirmed that the adaptive response did not correlate with the radiosensitivity of the peripheral blood lymphocytes.

Adaptation, Biological↗

PubMed1999

The role of human glutathione S-transferases M1 and T1 in individual susceptibility to bladder cancer.

Several genes involved in the metabolism of carcinogens have been found to be polymorphic in the human population, and specific alleles are associated with increased risk of cancer at various sites. This study is focused on the polymorphic enzymes glutathione S-transferase M1 (GSTM1) and T1 (GSTT1) that are involved in the detoxification of many xenobiotics involved in the etiology of bladder cancer. To investigate the role of GSTM1 and GSTT1 in bladder carcinogenesis, the polymerase chain reaction was used to determine GSTM1 and GSTT1 genotypes of cancer patients (n = 76) and controls (n = 248). The proportion of putative risk GSTM1 null genotype in the case group was 52.6%, compared to 49.6% in the control group, but the GSTT1 0/0 frequency in the bladder cancer group was significantly higher (P = 0.04) in comparison with the control group (27.6 vs 16.9%). Individuals lacking the GSTT1 gene are at an approximately 1.9-fold higher risk (OR = 1.87, C.I. 95% = 1.03-3.42) of developing bladder cancer in comparison with individuals with at least one active allele in the GSTT1 locus. A significantly higher incidence of GSTM1 deletion genotype (P = 0.02) was found in smokers with bladder cancer compared to the controls (70.6 vs 49.6%). Smokers lacking the GSTM1 gene are at an approximately 2.4-fold higher risk of bladder cancer (OR = 2.44, C.I. 95% = 1.10-5.30). The effect of smoking associated with the GSTT1 0/0 genotype was not found to affect the risk of bladder cancer.

Aged↗

PubMed1998

Cytogenetic monitoring in coke oven workers.

Cytogenetic markers (chromosomal aberrations, sister chromatid exchanges (SCE), cells with high frequency of SCE (HFC), the heterogeneity index SCE (SCE-H) and genetic polymorphism of genotypes GSTM1 and NAT2 were evaluated in the peripheral lymphocytes of 64 coke oven workers and 34 control subjects from the same plant. Personal monitors were used to evaluate exposure to eight carcinogenic (polycyclic aromatic hydrocarbons) PAHs, including B[a]P, during an 8-h working shift. Smoking habits were checked by urinary cotinine measurement. The exposure among coke oven workers ranged widely from 0.6 to 547 microgram/m3 and 2 to 50 137 ng/m3, for carcinogenic PAHs and B[a]P, respectively. The respective values in controls were 0.07 to 1.51 microgram/m3 and from 2 to 63 ng/m3. The results of biomonitoring in exposed vs. control subjects were as follows: frequency of chromosomal aberrations (% AB.C.), 2. 30% AB.C. vs. 1.09% AB.C. (P<0.05); sister chromatid exchanges, 7.47 SCE/cell vs. 5.49 SCE/cell (P<0.05); HFC, 5.94% vs. 2.06% (P<0.05) and SCE-H index, 1.49 vs. 1.01 (P<0.05). All the cytogenetic markers were significantly increased in the exposed vs. control groups. The effect of smoking was observed only in SCE when evaluated as HFC. Using individual exposure data for carcinogenic PAHs, a significant correlation between exposure and %AB.C. (r=0.372, P=0.0002), SCE/cell (r=0.331, P=0.001), HFC (r=0.467, P=0.007) and SCE/H (r=0. 286, P=0.004) was found. No effects of GSTM1 and NAT2 genotypes, individually or in combination, on the cytogenetic markers was observed. It is concluded that occupational exposure of coke oven workers involved in this study resulted in an increased level of chromosomal aberrations and SCE. The frequency of AB.C. and SCE/cell was found to be related to exposure to carcinogenic PAHs.

Arylamine N-Acetyltransferase↗

PubMed1998

Genetic polymorphism of glutathione S-transferases M1 and T1 as a risk factor in lung and bladder cancers.

A combined analysis of two polymorphic enzymes, glutathione S-transferase mu (GST M1) and q (GST T1) and their implication as cancer risk factors was performed in a case-control study of lung and bladder cancers. Using a multiplex polymerase chain reaction (PCR) based method, the frequency of the homozygous deleted GSTM1 and GSTT1 genotypes was examined in 117 lung cancer patients, 67 urinary bladder cancer patients, and in a community-based sample of 248 healthy, unrelated individuals. In both cancer groups the frequency of the GSTM1 null genotype was higher in comparison with that of the control group (59% and 59.7% vs. 49.6%), but this increase did not reach statistical significance (p > 0.05). After grouping by the smoking status, among smokers in both cancer groups (62.1% in lung cancer and 71.4% in the bladder cancer group, respectively) there were statistically significantly (p < 0.05) increased frequencies of the GSTM1 deletion genotype as compared to the control group (49.6%). Smokers with absence of the GSTM1 gene were at an approximately 1.7-fold higher risk for lung cancer (odds ratio--OR = 1.67, 95% confidence interval--CI 95% = 1.0-2.7, p = 0.04) and an approximately 2.5-fold higher risk for bladder cancer (OR = 2.54, CI 95% = 1.2-5.5, p = 0.02). As related to GSTT1, our study demonstrated an overall GSTT1 effect on bladder cancer risk. Individuals with absence of the GSTT1 gene were at an approximately 2.5-fold higher risk of developing bladder cancer. In the lung cancer cases, the frequency of the putatively high risk GSTT1 null genotype was not increased as compared with controls. No effect of smoking was found on risk of lung and bladder cancer associated with the GSTT1 0/0 genotype. In combined analysis, the obtained results suggested that individuals who were both GSTM1 null and GSTT1 null may be at increased risk because they lack both enzymes. The findings suggest that the GSTM1 null genotype may be associated with susceptibility to lung and urinary bladder cancer in dependence on the exposure to carcinogens in cigarette smoke and that the GSTT1 null genotype is not a critical factor in mediating the risk of lung cancer, but may be associated with an increased susceptibility to bladder cancer.

Aged↗