Measurement of telomere length in cells from pleural effusion: Asbestos exposure causes telomere shortening in pleural mesothelial cells

Our plain-English summary of Measurement of telomere length in cells from pleural effusion: Asbestos exposure causes telomere shortening in pleural mesothelial cells, by S. Aida, J. Aida, M. Naoi, et al (Pathology International, 2018).

The study

• Authors: S. Aida, J. Aida, M. Naoi, M. Kato, Y. Tsuura, I. Natsume, K. Takubo
• Journal: Pathology International
• Published: 2018;68(9):503-508
• Cited by: 6 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

We estimated the telomere lengths of neoplastic and non-neoplastic mesothelial cells and examined their correlation with asbestos exposure and the expression of markers of mesothelial malignancy. Cell blocks of pleural effusion obtained from 35 cases of non-neoplastic disease (NN), 12 cases of malignant mesothelioma (MM) and 12 cases of carcinomatous effusion due to lung adenocarcinoma (LA) were examined. Fifteen of the 35 NN cases had pleural plaques (NNpp+) suggestive of asbestos exposure, and the other 20 cases had no pleural plaques (NNpp-). Telomere length was measured using the tissue quantitative fluorescence in situ hybridization method, and expressed as normalized telomere-to-centromere ratio. NN cases had significantly longer telomeres than MM (P < 0.001) and LA (P < 0.001) cases. Telomeres in NNpp+ cases were slightly shorter than those of NNpp- cases (P = 0.047). MM and LA showed almost the same telomere length. NN cases with shorter telomeres tended to show aberrant expression of epithelial membrane antigen (EMA), CD146, glucose transporter 1 (GLUT1) and IGF-II messenger RNA-binding protein 3 (IMP3). These results suggest that telomere shortening and subsequent genetic instability play an important role in the development of MM. Measurement of telomere length of cells in pleural effusion might be helpful for earlier detection of MM.

© 2018 Japanese Society of Pathology and John Wiley & Sons Australia, Ltd.

In plain English

Researchers in Japan measured telomere length (telomeres are protective caps on the ends of chromosomes) in cells from fluid around the lungs, called pleural effusion. They examined samples from 35 people with non-cancerous effusions, 12 with malignant mesothelioma and 12 with effusions caused by lung adenocarcinoma. Of the 35 non-cancerous cases, 15 had pleural plaques on CT scan. The authors took the plaques as suggesting asbestos exposure and checked this against occupational and residential history. The other 20 had no plaques and no recorded exposure. Fiber types were not reported. Cells from non-cancerous effusions had significantly longer telomeres than mesothelioma or adenocarcinoma cells. Cells from people with plaques had slightly shorter telomeres than those without plaques (P = 0.047). Mesothelioma and adenocarcinoma cells had almost the same telomere length. Non-cancerous cases with shorter telomeres tended to show abnormal staining for four markers linked to mesothelioma, significantly so for CD146. The authors concluded that telomere shortening may play an important role in mesothelioma developing in asbestos-exposed patients, and that measuring it might help earlier detection.

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: Laboratory comparison of telomere length (by quantitative fluorescence in situ hybridization) and immunohistochemical staining in cell blocks of pleural effusion from different patient groups, compared by t test
• Who was studied: 59 cases of pleural effusion: 35 non-neoplastic (15 with pleural plaques on CT, 20 without), 12 malignant mesothelioma (diagnosis confirmed on thoracoscopic biopsy) and 12 lung adenocarcinoma. Authors were at hospitals and institutes in Tokyo and Yokosuka, Japan; study dates not given. The lung adenocarcinoma group was significantly younger than the other two groups (P = 0.001).
• Exposure: Asbestos exposure was inferred from pleural plaques on CT and confirmed from occupational and residential history; no fiber type or dose was reported. The 20 cases without plaques had no asbestos exposure history in hospital records. A history of asbestos exposure in hospital records was listed for 15 of the 35 non-neoplastic cases, 9 of the 12 mesothelioma cases and 1 of the 12 lung adenocarcinoma cases. All 15 plaque cases were considered benign asbestos-related pleural effusion, and mesothelioma was ruled out in them by thoracoscopic examination.
• Main results:
  • Non-neoplastic cases both with and without pleural plaques had significantly longer telomeres than malignant mesothelioma cases (P less than 0.001 without plaques; P = 0.002 with plaques) and than lung adenocarcinoma cases (P less than 0.001)
  • Mesothelial cells from non-neoplastic cases with pleural plaques had slightly shorter telomeres than those from cases without plaques; the difference was statistically significant (P = 0.047)
  • Malignant mesothelioma and lung adenocarcinoma cases showed almost the same telomere length
  • Most non-neoplastic mesothelial cells did not stain for EMA, CD146, GLUT1 or IMP3, though a small number showed aberrant positive staining. Among the 35 non-neoplastic cases, 27, 32, 33 and 29 respectively were entirely negative for these four markers.
  • Non-neoplastic cases with shorter telomeres tended to show aberrant expression of the four markers; this was statistically significant only for CD146
• The authors' conclusion: The authors concluded that telomere shortening and the resulting genetic instability play an important role in the development of malignant mesothelioma in asbestos-exposed patients. They also suggested that measuring telomere length in pleural effusion cells might help with earlier detection of mesothelioma. The article's title states that asbestos exposure causes telomere shortening; the study compared groups at a single point in time.

Topics

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

Medical terms in this study, explained in our Lexicon: Pleural Effusion, Asbestos Exposure, Mesothelial Cells, Cell Block, Mesothelioma, Lung Adenocarcinoma, Pleural Plaques, Fluorescence In Situ Hybridization (FISH).

Related studies

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• MMP-7 is a highly specific negative marker for benign and malignant mesothelial cells in serous effusions — B. Davidson, H.T. Stavnes, et al. (2016)
• Telomere length and TERT polymorphisms as biomarkers in asbestos-related diseases — A. Mervic, K. Goricar, et al. (2024)
• Ber-EP4 for differentiating adenocarcinoma from reactive and neoplastic mesothelial cells in serous effusions. Comparison with carcinoembryonic antigen, B72.3 and Leu-M1 — M.E. Bailey, R.W. Brown, et al. (1996)

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