Asbestos-induced mesothelioma: is fiber biopersistence really a critical factor?

Our plain-English summary of Asbestos-induced mesothelioma: is fiber biopersistence really a critical factor?, by E. Kagan (The American Journal of Pathology, 2013).

The study

• Author: E. Kagan
• Journal: The American Journal of Pathology
• Published: 2013;183(5):1378-1381
• Type of article: Comment
• Cited by: 5 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

This Commentary highlights the research by Qi et al detailing the similarities and differences between crocidolite and chrysotile asbestos in terms of their transcriptional effects and transforming actions in human mesothelial cells.

Published by Elsevier Inc.

In plain English

This article was a commentary, not an original study. The author discussed a laboratory study by Qi et al, published in the same journal issue. That study compared crocidolite and chrysotile fibers on cultured human mesothelial cells from patients with benign effusions. As the commentary reported it, both fiber types killed the cells in a dose-dependent way, with chrysotile more toxic than crocidolite. Both fibers also raised the inflammatory signals TNF-alpha and HMGB1, significantly more so after chrysotile. Chrysotile showed limited ability to transform the cells compared with crocidolite, judged by counts of three-dimensional foci. The study found 57 genes with changed activity across 48-hour and 5-week cultures, and early gene responses to the two fibers were described as similar. At 5 weeks, gene activity in chrysotile-treated cultures had returned to baseline, while crocidolite produced a more persistent response. The author concluded that these findings were consistent with greater biopersistence of crocidolite than chrysotile. The author cautioned that the results may not easily apply to real-world human exposure, partly because reference fiber samples and a possibly high laboratory dose were used.

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: Commentary on a single in vitro laboratory study (Qi et al) published in the same journal issue; not original research
• Who was studied: In the study discussed: primary cultured human mesothelial cells obtained from patients with benign effusions
• Exposure: Crocidolite and chrysotile asbestos, using UICC and other asbestos reference samples, with or without TNF-alpha or macrophage co-cultures
• Main results:
  • In the cultured human mesothelial cells, both crocidolite and chrysotile caused significant dose-dependent cell death, greater with chrysotile than with crocidolite (as reported by the commentary)
  • Both fiber types induced TNF-alpha and HMGB1 release from the mesothelial cells, and the effects were significantly greater after chrysotile than after crocidolite
  • Chrysotile had limited transforming potential in vitro compared with crocidolite, measured by the number of three-dimensional foci in cultured mesothelial cells
  • The study identified a collection of 57 differentially expressed genes across 48-hour and 5-week cultures
  • The commentary described the early transcriptional responses to crocidolite and chrysotile as similar, with crocidolite producing a more persistent response over time
  • At 5 weeks, gene expression changes in chrysotile-treated cultures had returned to baseline, while NF-kB was a top predicted regulator in crocidolite-exposed cultures
• The authors' conclusion: The author concluded that the Qi et al findings were consistent with greater biopersistence of crocidolite than chrysotile, and that they underline the prosurvival roles of TNF-alpha and HMGB1 in mesothelial cultures treated with either fiber
• Limitations the authors state:
  • The observations may not be easily extrapolated to real-world human asbestos exposure
  • The reference asbestos samples may differ from fibers historically mined, milled and used in industry
  • The laboratory fiber dose may exceed what reaches tissue in the body
  • Human and rodent mesothelial cells differ in how readily they transform in culture

Topics

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

Medical terms in this study, explained in our Lexicon: Mesothelioma, biopersistence, Crocidolite, Chrysotile, Mesothelial Cells.

Related studies

• Continuous exposure to chrysotile asbestos can cause transformation of human mesothelial cells via HMGB1 and TNF-α signaling — F. Qi, G. Okimoto, et al. (2013)
• TNF-alpha inhibits asbestos-induced cytotoxicity via a NF-kappaB-dependent pathway, a possible mechanism for asbestos-induced oncogenesis — H. Yang, M. Bocchetta, et al. (2006)
• Activated TNF-alpha/NF-kappaB signaling via down-regulation of Fas-associated factor 1 in asbestos-induced mesotheliomas from Arf knockout mice — D.A. Altomare, C.W. Menges, et al. (2009)
• Programmed necrosis induced by asbestos in human mesothelial cells causes high-mobility group box 1 protein release and resultant inflammation — H. Yang, Z. Rivera, et al. (2010)
• Asbestos induces mesothelial cell transformation via HMGB1-driven autophagy — J. Xue, S. Patergnani, et al. (2020)
• SV40-induced expression of calretinin protects mesothelial cells from asbestos cytotoxicity and may be a key factor contributing to mesothelioma pathogenesis — T. Henzi, W.V. Blum, et al. (2009)

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