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Multiple myeloma is a malignant disease caused by malign transformation of B-cells, their clonal proliferation and the accumulation of myeloma cells in the bone marrow. These cells are set apart by a pronounced genetic instability. Chromosomal abnormalities are probably the most important prognostic factors in myeloma which influence the division of the patients into individual sub-groups each with a different developmental process of the disease and thus a different approach during treatment. The study summarizes the methodological approaches and current options in classical and molecular cytogenetics during the examination of cytogenetic changes in multiple myeloma. It presents the most common types of numerical and structural chromosomal changes found in the karyotype of multiple myeloma patients, and their prognostic importance.

Background: Cytogenetic abnormalities of chromosome 13 are emerging as important prognostic factors in multiple myeloma and have been associated with poor prognosis., Methods and Results: The occurrence of 13q14 deletion and other standard laboratory parameters were determined in 40 patients with multiple myeloma. We found that interphase fluorescence in situ hybridization using a locus specific probe for RB1 gene on immunomagnetically selected myeloma cells was more sensitive than non selected cells. The 13q14 deletion was found in 10 of 40 (25.0%) of bone marrow samples without cell selection and in 25 of 40 (62.5%) of samples with CD138+ enriched myeloma cells. Negative correlation was found between albumin and the 13q14 deletion in separated (p = 0.003) as well as in cells without selection (p = 0.010). No significant correlation was found in overall survival of separated and unseparated cells (p = 0.830; p = 0.260) and a similar result was obtained for treatment response after transplantation of separated cells (p = 0.520) or non-separated cells (0.190)., Conclusions: Our results confirm that immunomagnetic selection of CD138+ cells increases the probability of detection of the 13q14 deletion in bone marrow samples. The correlation was found between albumin and the 13q14 deletion in both of type of cells.

Accurate prognostic evaluation of patients with multiple myeloma (MM) is required for their stratification for more adequate therapy. Chromosomal G-banding and interphase fluorescence in situ hybridization (FISH) on cell-nonspecific samples and on myeloma cells selected by magnetic-activated cell separation (MACS) were used to study 13 samples from 12 multiple myeloma (MM) patients. Bone marrow (BM) samples were analysed using three approaches. Standard mitotic samples were prepared and analysed after G-banding. Interphase FISH was performed to detect the 13q14 deletion in unselected BM cells. In parallel, myeloma cells were selected from the BM using the CD138-specific antibody. The high-purity myeloma cell suspension was then analysed by interphase FISH for the 13q14 deletion. Magnetic separation yielded enriched myeloma cell suspensions with the mean viability of 98.0% (range: 97.0%-99.0%), and the purity of 97.6% (range: 87.2%-99.2%) as detected morphologically, and 85.2% (range: 44.8%-98.4%) as detected by immunophenotyping for CD138+ cells. Interphase FISH revealed the 13q14.3 deletion in 5 of 13 (38.5%) of cell-nonspecific samples and in 9 of 13 (69.2%) of enriched myeloma cell suspensions. In conclusion, interphase FISH on immunomagnetically selected MM cells increases the detection of the 13q14 deletion in BM samples from the patients with MM.

The Somatic Mutation and Recombination Test (SMART) in wing cells of Drosophila melanogaster, the Vicia faba cytogenetic tests-Sister Chromatid Exchange (SCE) and Micronucleus Test (MN), and the Müller test for gametic mutations in Arabidopsis thaliana were used for genotoxicity testing of environmental samples of pollutants from the surroundings of LACHEMA chemical factory (Brno, Czech Republic) and DEZA factory in Valasské Mezirící (Moravia, Czech Republic). Tested soil and air samples were taken from the near vicinity of both factories. The surroundings of both sites are heavy loaded by exhalation of chemicals from the factories. Chemical analyses of the 16 Polycyclic Aromatic Hydrocarbons (PAHs) according to the United States Environmental Protection Agency (US EPA) list of priority pollutants and heavy metals were performed in both soil and air samples. The Drosophila wing spot test was positive in 70.6% of the tested samples, the Vicia sister chromatid exchange test in 62.5%, and the Arabidopsis Müller test in 58.9%. The micronucleus Vicia faba test was quite insensitive in tested environmental samples. The concordance between SMART and SCE was 62.5%, between SMART and Müller test 76.5%, and between Müller test and SCE 100%. Total concordance of these three tests was 79.7%. Müller test for gametic mutation in Arabidopsis thaliana and cytogenetic SCE test in Vicia faba seem to be quite sensitive and convenient plant bioassays for assessing the mutagenic potential of environmental agents, when compared to the SMART test in Drosophila melanogaster.

In a population of plant meristematic cells of Vicia faba the frequency of sister chromatid exchanges (SCEs), incidence of chromosomal aberrations and mitotic activity of cells was evaluated after short-term treatment (1 h) with antitumour active platinum complexes cis-DDP, CHIP IV, CBDCA, oxo-Pt and antitumour inactive trans-DDP. It was found that the action of platinum compounds in equimolar concentration 3.33 microM increases the level of SCEs 1.3 to 6.4-fold. The maximum effect in terms of SCE formation was observed after cis-DDP. Comparison of the incidence of SCEs and chromosomal aberrations in plant cells demonstrated that the tested drugs had a greater effect on SCE formation than on chromosomal aberration induction. Inhibition of mitotic activity correlated with the total cytogenetic damage to chromosomes of Vicia faba cells.