Chromosomes and chromosomal evolution in human mesotheliomas as reflected in sequential analyses of two cases

Our plain-English summary of Chromosomes and chromosomal evolution in human mesotheliomas as reflected in sequential analyses of two cases, by G. Stenman, K. Olofsson, T. Månsson, et al (Hereditas, 1986).

The study

• Authors: G. Stenman, K. Olofsson, T. Månsson, B. Hagmar, J. Mark
• Journal: Hereditas
• Published: 1986;105(2):233-9
• Type of article: Case report
• Cited by: 22 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Sequential G-banding analyses were performed on two malignant mesotheliomas. The results were interpreted together with data from 3 previously reported cases. Four of the 5 mesotheliomas showed well established stemlines with distinctive numerical and structural changes while the fifth case, which was analyzed six times during a two-year period, was characterized by either only normal karyotypes or, more often, a mixture of normal and abnormal karyotypes. Several of the markers found in the 5 cases were identical or very similar. The chromosomes most frequently involved in marker formation were Nos. 3 and 6 and, to a lesser extent, also Nos. 2,7 and 13. Non-random numerical changes, usually losses, preferentially affected Nos. 14 and 22. The relationships of affected chromosomes and chromosome regions to known localizations of proto-oncogenes are considered. Also, the chromosomal evolution and the impact of certain etiological factors, particularly asbestos, on the chromosomal picture in mesotheliomas are discussed.

PubMed has no abstract for this study. This is the authors' abstract, copied from the article.

In plain English

This report described repeated chromosome analyses of tumor cells in the pleural fluid of two men with malignant mesothelioma. Case 1, aged 72, had been exposed to asbestos as a plumber. Case 2, aged 70, had about 20 years of occupational asbestos exposure. The authors compared them with three previously published cases. Case 1 was analyzed six times over two years. Its samples showed either only normal chromosome patterns or, more often, a mix of normal and abnormal patterns. In one sample, among cultured cells in the diploid range, no two had the same chromosome pattern, apart from 5 cells with normal patterns and 2 with an extra chromosome 7. Case 2 showed a consistent abnormal cell line, seen again in 4 of 14 analyzed cells eight months later. Across the five cases, chromosomes 3 and 6 were most often rearranged, and losses mainly affected chromosomes 14 and 22. The authors noted that these regions matched known locations of cancer-related genes, whose role, they said, had to await molecular study. In Case 1, dividing cells were scarce and often of poor quality.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Case report with sequential chromosome (G-banding) analyses of two malignant mesotheliomas, interpreted together with three previously published cases
• Who was studied: Two men with malignant mesothelioma and pleural effusions, reported from hospital laboratories in Sweden, with effusions studied between 1983 and 1985. Case 1 was a 72-year-old former plumber with a predominantly monophasic mesothelioma. Case 2 was a 70-year-old man with a predominantly epithelial mesothelioma. Results were compared with 3 earlier published cases, 5 in all with complete banding data.
• Exposure: Occupational asbestos exposure, as reported in the case histories: work as a plumber (case 1) and about 20 years of occupational exposure (case 2). No fiber type or dose was given, and exposure was not measured.
• Main results:
  • Case 1, cultured cells from preparation 3: among the cells with counts in the diploid region that were analyzed by banding, there were 5 normal cells and two hyperdiploid cells that had gained one chromosome no. 7. Apart from these, no two cells had the same karyotype, and 18 different marker chromosomes were seen. The polyploid cells in the same preparation mostly shared a set of 5 new marker types.
  • Case 1, preparation 6: no definite stemline was found, but the earlier diversity had been replaced by a modal population sharing the same marker set.
  • Case 2, first preparation: a pseudodiploid stemline marked mainly by structural rearrangements, especially deletions.
  • Case 2, second preparation from the recurrent effusion 8 months later: 4 of the 14 karyotyped cells had changes identical to the original stemline, and one more cell was closely related. The remaining cells had a normal karyotype.
  • Across the 5 mesotheliomas with complete data (2 here, 3 published earlier), 4 had a well-established abnormal stemline. Case 1 was the exception, showing either only cells with a normal karyotype or a mixture of normal and abnormal karyotypes.
  • Across the 5 cases, chromosomes 3 and 6 were most often involved in marker formation, and to a lesser extent chromosomes 2, 7 and 13.
  • Across the 5 cases, non-random changes in chromosome number, usually losses, mainly affected chromosomes 14 and 22.
  • The authors reported good agreement between the chromosome regions often rearranged in these mesotheliomas and the known locations of oncogenes or oncogene-related sequences.
• The authors' conclusion: The authors proposed an evolutionary pattern for mesothelioma chromosomes. In their view, tumors start without gross changes, then generate varied abnormal cells, which are selected until an abnormal stemline forms. They concluded that any role of oncogenes in causing mesothelioma had to await future molecular analyses.
• Limitations the authors state:
  • Dividing cells were scarce and often of poor quality. Because of this, two examinations from case 1 (preparations 3 and 6) were supplemented with short-term cultured material.
  • Of 12 mesotheliomas with banding data available at the time, only 5 had complete data, so the authors described their evaluation of recurrent changes as preliminary.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Mesothelioma.

Medical terms in this study, explained in our Lexicon: Mesothelioma, Malignant Mesothelioma.

Related studies

• Abnormalities of chromosomes 7 and 22 in human malignant pleural mesothelioma: correlation between Southern blot and cytogenetic analyses — M. Tiainen, J. Kere, et al. (1992)
• Further analyses of the evolutionary characteristics of a sequentially studied human malignant mesothelioma — J. Mark, K. Olofsson, et al. (1989)
• Chromosomal abnormalities and their correlations with asbestos exposure and survival in patients with mesothelioma — M. Tiainen, L. Tammilehto, et al. (1989)
• Malignant mesothelioma: clinical characteristics, asbestos mineralogy and chromosomal abnormalities of 41 patients — L. Tammilehto, T. Tuomi, et al. (1992)
• Specificity of asbestos-induced chromosomal aberrations in short-term cultured human mesothelial cells — K. Olofsson, J. Mark (1989)
• Translocation (3;3)(p14;q29) as the primary chromosome abnormality in a peritoneal mesothelioma — M.R. Teixeira, K.E. Giercksky, et al. (1998)

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