Immunohistochemical staining of ras oncogene product in neoplastic and non-neoplastic mesothelial tissues: immunoreactivity for N-ras and lack of immunohistochemical staining for Ha-ras and K-ras

Our plain-English summary of Immunohistochemical staining of ras oncogene product in neoplastic and non-neoplastic mesothelial tissues: immunoreactivity for N-ras and lack of immunohistochemical staining for Ha-ras and K-ras, by M. Ramael, I. Deblier, C. Eerdekens, et al (The Journal of Pathology, 1993).

The study

• Authors: M. Ramael, I. Deblier, C. Eerdekens, G. Lemmens, W. Jacobs, E. Van Marck
• Journal: The Journal of Pathology
• Published: 1993;169(4):421-4
• Cited by: 16 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Immunohistochemical staining of 36 malignant mesotheliomas and 45 cases of non-neoplastic mesothelium including 20 specimens with signs of hyperplasia were investigated using murine monoclonal antibodies directed against p21 ras protein, Ha-ras protein, K-ras protein, and N-ras protein. All cases of non-neoplastic mesothelium and the majority of the malignant mesotheliomas (78 per cent) showed cytoplasmic and often submembranous immunoreactivity in more than 50 per cent of the cells with both the pan-ras and N-ras antibody. No immunoreactivity was observed for Ha- and K-ras. There was no statistically significant difference with respect to immunoreactivity between neoplastic and non-neoplastic mesothelium or between the various mesothelioma subtypes.

In plain English

This laboratory pathology study from the University Hospital Antwerp in Belgium examined pleural tissue samples for proteins made by a family of genes called ras. The authors stained 36 malignant mesothelioma specimens (25 epithelial, 8 mixed and 3 mesenchymal) and 45 samples of non-neoplastic (non-cancerous) pleural mesothelium, 20 of which showed hyperplasia. They used antibodies against ras protein in general (pan-ras) and against three specific forms: Ha-ras, K-ras and N-ras. The article does not report the patients' asbestos exposure. Most mesotheliomas (78 per cent) and all non-neoplastic samples showed staining in more than 50 per cent of cells with the pan-ras and N-ras antibodies. No mesothelial cells stained for Ha-ras or K-ras. Every case that stained with the pan-ras antibody also stained with the N-ras antibody. The authors found no statistically significant difference in staining between cancerous and non-cancerous mesothelium, or between reactive and normal mesothelium. The authors concluded that N-ras protein, but not Ha-ras or K-ras protein, is present in both cancerous and non-cancerous mesothelium, and that ras protein staining cannot be used to tell malignant from benign mesothelium.

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 immunohistochemistry study of stored (paraffin-embedded) tissue specimens, comparing malignant mesothelioma with non-neoplastic mesothelium
• Who was studied: 36 malignant mesothelioma specimens (25 epithelial, 8 mixed, 3 mesenchymal) and 45 pleural tissue specimens or pleural exudates with non-neoplastic mesothelium, including 20 hyperplastic specimens; Department of Pathology, University Hospital Antwerp, Belgium. The mesothelioma patients had a mean age of 60.8 years (range 39 to 80) and a male:female ratio of 6.2:1. Patients with a previous history or suspicion of malignancy were excluded from the non-neoplastic group.
• Exposure: The article does not report asbestos or other exposure. The study measured staining for ras proteins (pan-ras, Ha-ras, K-ras and N-ras) using mouse monoclonal antibodies.
• Main results:
  • Malignant mesotheliomas: 78 per cent showed pan-ras and N-ras staining in more than 50 per cent of tumour cells.
  • Non-neoplastic mesothelium: all cases showed pan-ras and N-ras staining in more than 50 per cent of cells.
  • No staining of mesothelial cells was seen with the Ha-ras and K-ras antibodies, in either cancerous or non-cancerous tissue.
  • All cases that stained with the pan-ras antibody also stained with the N-ras antibody. The authors took this to indicate that the ras staining came from N-ras protein.
  • No statistically significant difference in pan-ras or N-ras staining was found between non-neoplastic and neoplastic mesothelium, or between reactive and normal mesothelium (P greater than 0.05, chi-square test).
  • Stromal connective tissue cells did not stain with any of the four antibodies.
• The authors' conclusion: The authors concluded that the p21 protein of the N-ras gene, but not of the Ha-ras and K-ras genes, is expressed in both neoplastic and non-neoplastic mesothelium. They also concluded that staining for p21 ras protein cannot be used to distinguish between malignant and benign mesothelium.

Topics

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

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

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