ABSTRACT
A classical cytogenetic analysis was applied to analyse karyotypes of 9 cell lines derived from laryngeal cancer. The most frequent aberration was a deletion of the whole sex chromosome Y. An abundance of somatic chromosome alterations was further analysed to find correlation with tumour staging and grading. A conventional cytogenetic analysis seems to be not sufficient to recognize chromosome alterations specific for a given tumor stage. On the other hand, an analysis in respect to histologic grading has indicated for an association between rearrangement of 9 chromosome and a high tumor aggressiveness. It seems that a combination of conventional cytogenetics with molecular methods (FISH, CGH) would be helpful in diagnosing of laryngeal cancer.
Subject(s)
Chromosome Aberrations/genetics , Laryngeal Neoplasms/diagnosis , Laryngeal Neoplasms/genetics , Cell Line , Genetic Testing , Humans , Karyotyping , Laryngeal Neoplasms/pathology , Neoplasm Staging , Y Chromosome/geneticsABSTRACT
The bleomycin test is a recognised method of evaluation of hidden genetical instability. The concept of the test consists in inducing chromosome aberrations in lymphocytes exposed in vitro to bleomycin and subsequent quantitative analysis of chromosome breaks. The study material was whole venous blood from 61 laryngeal cancer patients and from 30 healthy persons taken as a control. For each patient two parallel cultures where carried out in the standard procedure. Bleomycin was added to one of the cultures to induce chromosome breaks. Then, in microscopic metaphasal plates stained by Giemsa dye, the chromosome instability index estimated as a number of chromosome breaks per cell (b/c) and the percentage of cells with chromosome breaks were calculated. Higher indices of chromosome instability were demonstrated in laryngeal cancer patients in comparison to the controls. The persons with chromosome instability (b/c > 0.8) or with chromosome oversensitivity to mutagens (b/c > 1) were identified only among larynx cancer subjects. Furthermore, it was established that an increased chromosome instability is associated with high aggressiveness recognised by histological grading. The latter finding requires confirmation on an enlarged group of subjects.
Subject(s)
Bleomycin , Chromosome Aberrations , Chromosome Aberrations/diagnosis , Chromosome Aberrations/genetics , Chromosome Disorders , Laryngeal Neoplasms/genetics , Adult , Aged , Chromosome Aberrations/pathology , Female , Humans , Laryngeal Neoplasms/blood , Laryngeal Neoplasms/pathology , Lymphocytes/drug effects , Lymphocytes/pathology , Male , Middle Aged , Neoplasm InvasivenessABSTRACT
Chromosome instability is associated with an increased risk of malignancy. However, the quantitative analysis of chromosome breaks provided by the bleomycin test requires additional analysis aimed for the localisation of chromosome aberrations. For this reason, the metaphasis slides prepared for bleomycin test were stained with fluorochrome DAPI to estimate chromosome breaks in particular chromosomes. The additional staining of chromosomes can be recognised as an extension of the classical bleomycin test addressed for identification of structural aberrations. Preliminary results indicate that the most frequent chromosome breaks were found in chromosomes 1, 2, 3, 7 and 13.
Subject(s)
Bleomycin , Chromosome Aberrations/diagnosis , Chromosomes, Human, 1-3 , Chromosomes, Human, Pair 13 , Chromosomes, Human, Pair 7 , Laryngeal Neoplasms/diagnosis , Laryngeal Neoplasms/genetics , Aged , Aged, 80 and over , Chromosome Aberrations/genetics , Chromosome Disorders , Genetic Markers , Humans , Laryngeal Neoplasms/blood , Lymphocytes/drug effects , Male , Middle AgedABSTRACT
The aim of the article is a review of own cytogenic studies on laryngeal cancer confronted with the literature data. Spontaneous and bleomycin-induced chromosome instability was analysed in peripheral blood lymphocytes in relation to genetic risk of cancer incidence and progression. Comparative genome hybridization (CGH) was applied to demonstrate gains and losses of DNA copy number in tumour and non-tumour laryngeal mucosa. The profiles of imbalances of DNA copy number were shown to differ between metastazing and non-metastazing tumours. Preliminary data indicate a frequent loss of Y chromosome in tumour cells. The loss of heterozygosity at chromosome p53 locus (17p) has been shown to be more frequent than at chromosome locus coding 16 gene (9p). Altogether, the experiments have proven that a dynamics of chromosome aberrations is highest at the stage of metastasis.
