Monitoring of molecular and cytogenetic damage in lymphocytes from three persons with polycystic kidney disease.

BACKGROUND: Much interest has been generated in the studies that would help to understand whether there is a causal association between disease and various types of molecular or cytogenetic damage detected in human cells. MATERIALS AND METHODS: The aims of this study were to elicit the possible association between DNA and cytogenetic damage induced in lymphocytes of three members of a family with autosomal dominant polycystic kidney disease (ADPKD). The predictability to develop cancer or to sensitive response to environmental exposure of the young girl at the age of 19, her brother (9 years old) and a maternal aunt at the age of 41 were sought. Cytogenetic studies, analysis of DNA damage by single cell gel electrophoresis assay (SCGE known as a Comet assay), and analysis of p21ras protein level in blood plasma were carried out on their lymphocytes. RESULTS: The analysis for presence of chromosome aberrations in the first mitosis and sister chromatid exchanges in the second mitosis revealed elevated levels of cytogenetic biomarkers when compared to the mean values observed in the reference group in environmental biological monitoring studies. Results of sister chromatid exchanges (SCE) and percent of cells with elevated number of exchanges (high frequency cells) that were significantly higher in two probands had demonstrated susceptibility to or possibility of environmental exposure (pesticides, smoking). The results of this study show that the lymphocytes of two persons revealed increased sensitivity to 0.5 Gy dose of gamma radiation expressed in the increased, although statistically insignificant, damage detected on the molecular level after cell irradiation. CONCLUSIONS: The latter might be associated with a specific aberration present in the cells of these persons. But final conclusions can be arrived at when an application of FISH technique is completed.

Cytogenetic damage and ras p21 oncoprotein levels from patients with chronic obstructive pulmonary disease (COPD), untreated lung cancer and healthy controls.

The purpose of the present communication was to determine in patients with chronic obstructive pulmonary disease (COPD), untreated lung cancer and healthy controls if there was a possible association between the disease state and biomarkers of cytogenetic damage and ras p21 oncoprotein levels, and if various exogenous confounding factors such as smoking habit and endogenous ones (sex, cancer in the immediate family) could affect these biomarkers. The individuals in all groups were as well-matched as possible for age to determine if this could be eliminated as a confounder. Peripheral blood and plasma were collected from 20 COPD patients, 31 cancer patients and 20 healthy controls. Chromosomal aberrations (CA), sister chromatid exchanges (SCE) and high frequency SCE cells (HFC) were examined from the blood and ras p21 oncoproteins from the plasma. These parameters were used as biomarkers of genotoxic anomalies. All the biomarkers were examined for their relationship to the confounding factors. Results were analysed by a t-test, analysis of variance (ANOVA) and stepwise multivariate regression analysis. There was an increase in CA, although not statistically so, in COPD and cancer patients by comparison with healthy controls, but there was a statistically significant increase in SCE, HFC and ras p21 oncoproteins. There was also a statistically significant difference between respiratory volume parameters in COPD patients and controls. Respiratory parameters were not measured in cancer patients. Ras p21 oncoproteins were also statistically significantly increased in the COPD and cancer patients, suggesting that the disease state alone might be sufficient to increase the oncoproteins, or that some of the COPD patients were in the process of developing cancer or perhaps some would die from COPD before cancer developed. Smoking was shown to have a marked effect on all parameters investigated. Ex-smokers showed less effects. Since age was very well controlled, there was little effect due to age. There was an effect due to sex, but cancer in the immediate family had little effect on any of the parameters.

Factors affecting various biomarkers in untreated lung cancer patients and healthy donors.

The purpose of the present communication was to determine in lung cancer patients and healthy donors if there was a possible association between cancer and biomarkers of cytogenetic damage and ras p21 oncoprotein levels, and if various exogenous confounding factors (such as smoking habit) and endogenous ones (age, sex, etc.) could affect these biomarkers. Peripheral blood and plasma were collected from 31 lung cancer patients prior to treatment and 35 healthy donors of a similar socioeconomic status and from the same region in Poland. Chromosomal aberrations (CA), sister chromatid exchanges (SCE), high frequency cells (HFC), and proliferative rate index (PRI) were examined from the blood and ras p21 oncoproteins from the plasma. These parameters were used as biomarkers of genotoxic anomalies. All the biomarkers were examined for their relationship to confounding factors of age, sex, smoking habit, and immediate family cancer history. Results were analyzed by a t-test, analysis of variance (ANOVA), and stepwise multivariate regression analysis. All types of CA (including and excluding gaps), percent aberrant cells, SCE, and ras p21 oncoproteins were statistically significantly higher in cancer patients than in the healthy donors. Although there were smaller numbers of females in the cancer patients group who were older than the males, there was a difference due to sex (gender) with statistically significant increases in females for CA, SCE, and HFC, but there was no increase for ras p21 oncoproteins. Cytogenetic damage was not related to other cancers in the immediate families of the groups. All major CA parameters differed significantly between smokers and non-smokers in the cancer patients group, and SCE and HFC differed in the healthy donors group. Such parameters also showed a significant variability with the number of cigarettes smoked and the years of smoking habit. Multivariate regression analyses showed a significant association between cytogenetic damage, ras p21 oncoproteins, and cancer. In conclusion, cytogenetic damage and ras p21 oncoproteins in this study appear to be biomarkers associated with cancer, but have not been proved causally, and confounding factors such as age, sex (gender), and smoking can have an impact on them.

Biological monitoring of workers exposed to emissions from petroleum plants.

This paper presents some of the results from the Commission of the European Communities collaborative research program (contract number EV5V-CT92-0221), whose aim is to investigate the relationship between exposure to petroleum emissions, benzene, and induction of genetic damage in human cells. Twenty-four workers from petroleum plants in Poland and 35 unexposed controls were examined for cytogenetic effects and ras oncoprotein levels and their relationship to confounding factors (e.g., smoking habit, sex family cancer history, and seasonal influence). Preliminary data of chromosome aberrations (CA) and sister chromatid exchanges (SCE) showed differences among sampling subgroups. In this present study, the levels of ras p21 proteins were determined and further analyses of CA, SCE, high frequency cells (HFC), and proliferative rate index (PRI) have been undertaken. Results show that the exposed group has statistically significant increases in CA, and percent of aberrant cells. There were no differences between exposed and unexposed groups in SCE, HFC, PRI, or the levels of ras p21 proteins. Smoking was found to statistically significantly affect levels of CA, percent of aberrant cells, SCE, HFC, and ras proteins. Sister chromatid exchanges were also statistically significantly sex dependent (7.5 breaks/cells for females and 6.8 breaks/cell for males). There were no statistically significant differences for CA, percent aberrant cells, SCE, HFC, or ras p21 protein levels in subgroups characterized according to cancer cases reported in the immediate family. A seasonal variability was shown with statistically significant increases in various biomarkers in the winter. Unexposed groups also showed increases due to smoking and season. The nonsmoking group individuals also showed statistically significant increases in cytogenetic damage with exposure.