Immunoreactivity for c-fos and c-myc protein with the monoclonal antibodies 14E10 and 6E10 in malignant mesothelioma and non-neoplastic mesothelium of the pleura.

We studied immunoreactivity for c-fos protein and c-myc protein in malignant mesothelioma (36 cases) and non-neoplastic pleural mesothelium (45 cases) using the murine monoclonal antibodies 14E10 and 6E10. All malignant mesotheliomas and cases with non-neoplastic mesothelium exhibited not only nuclear but also cytoplasmic immunoreactivity for c-fos and c-myc protein in the majority of mesothelial cells. There was no statistically significant difference between the various mesothelioma subtypes or between neoplastic and non-neoplastic mesothelium for c-fos protein immunoreactivity (p > 0.05). There was statistically significant difference between neoplastic and non-neoplastic mesothelium for c-myc protein immunoreactivity (p < 0.01). We conclude that immunoreactivity for c-fos and c-myc protein is present in both non-neoplastic and neoplastic mesothelium, but that a higher proportion of neoplastic mesothelial cells are immunoreactive for c-myc protein when compared with non-neoplastic mesothelium.