cytochalasin-b and Chromosomal-Instability

Chromosomal instability could be one of primary causes for malignant cell transformation. The objective of the present study was to evaluate the spontaneous genetic damages in circulated lymphocytes of newly diagnosed cancer patients by using cytokinesis-block micronucleus (CBMN) assay, with respect to the factors that might affect micronucleus frequency (i.e. age, gender, smoking habits and cancer sites). Micronuclei (MN) are small nuclei that are originated from chromosome fragments or whole chromosomes. The analyzed samples included 44 untreated cancer patients (19 females and 25 males with mean age of 60.89 years) with different cancer sites (12 patients with breast cancer, 5 with uterine cancer and 27 with cancer of pharynx). Control group included 40 healthy donors (28 females and 12 males with mean age of 43.95 years). The mean baseline MN frequency was significantly higher (p < 0.001) in cancer patients (15.18 +/- 5.05 MN/1000 BN cells ranging from 4 to 27) than the baseline frequency in healthy controls (6.45 +/- 2.75 MN/1000 BN cells, ranging from 1 to 11). There was no gender difference in baseline MN frequency in cancer patients and healthy controls. Moreover, the MN frequency did not significantly differ among cancer sites, and between smokers and non-smokers in both patient and control samples. In conclusion, untreated cancer patients may be associated with an increase of chromosomal instability in peripheral blood lymphocytes, irrespective of gender, cigarette smoking and cancer sites.

Topics: Adult; Aged; Aged, 80 and over; Aging; Breast Neoplasms; Chromosomal Instability; Cytochalasin B; Cytokinesis; Female; Humans; Leukocytes, Mononuclear; Male; Micronuclei, Chromosome-Defective; Micronucleus Tests; Middle Aged; Neoplasms; Organ Specificity; Pharyngeal Neoplasms; Sex Characteristics; Smoking; Uterine Neoplasms

We studied micronucleus frequencies in former German uranium miners of the Wismut SDAG (Sowjetisch-Deutsche Aktiengesellschaft). Various other groups were analyzed for comparison (individuals with lung tumors or lung fibrosis, controls). We had shown previously that micronucleus frequencies were not different among the various groups. Differences were observed, however, when centromere-positive and -negative micronuclei were distinguished. In the analyses presented here, we looked for the effects of smoking habits, alcohol consumption, vitamin uptake, chronic diseases, allergies, doing sports, gamma-GT (gamma-glutamyltranspeptidase), lymphocyte numbers, CEA (carcinoembryonic antigen), X-ray diagnostics, computer tomographies, and scintigraphies. With the exception of more than one scintigraphy carried out during the last four months before micronucleus analysis, none of the factors mentioned above significantly affected micronucleus numbers. One result deserves specific attention: individuals with low percentages of binucleated lymphocytes after in vitro cytochalasin B exposure showed higher micronucleus frequencies than those individuals with high percentages of binucleated cells. The same result was obtained for various other populations that we monitored in the past.

Topics: Alcohol Drinking; Alpha Particles; Cell Nucleus; Centromere; Chromosomal Instability; Cytochalasin B; Dose-Response Relationship, Radiation; Gamma Rays; Germany; Life Style; Lung Neoplasms; Lymphocytes; Micronucleus Tests; Mining; Occupational Diseases; Occupational Exposure; Pulmonary Fibrosis; Radionuclide Imaging; Radon; Risk Factors; Smoking; Time Factors; Uranium