Over-expression of tenascin-C in malignant pleural mesothelioma.
OBJECTIVE
Tenascin-C is an extracellular matrix glycoprotein known to have anti-adhesive characteristics and to be expressed in various human malignant neoplasms. We hypothesized that the expression of tenascin-C would be increased in human malignant pleural mesothelioma, and its accumulation associated with the prognosis of the patients with this disease.


RESULTS
Thirty-seven cases of mesothelioma were studied by immunohistochemically using a monoclonal antibody against tenascin-C, and with a semiquantitative scoring system for tenascin-C in different areas of the tumours. In 10 selected cases tenascin-C mRNA in-situ hybridization was also analysed. Since transforming growth factor-beta (TGF-beta) is known to induce both the synthesis of tenascin-C and the growth of mesotheliomas, an immunohistochemical analysis of TGF-beta 1, -beta 2 and -beta 3 was also performed. Normal pleura (n = 7) and metastatic pleural adenocarcinomas (n = 7) were used as controls. Tenascin-C protein was expressed in every histological subtype of malignant mesothelioma, being most prominent in the fibrotic stroma of a tumour, around tumour cells and at the invasive border, whereas tenascin-C mRNA was scarce in tumour cells. The patients with less immunohistochemical expression for tenascin-C tended to live longer (P = 0.028 by Fishers' exact probability test). All mesotheliomas showed positivity for at least one isoform of TGF-beta.


CONCLUSIONS
In conclusion, high expression of tenascin-C protein in malignant pleural mesotheliomas may play a role in its invasive growth, and might serve as a prognostic marker of the disease.
Kaarteenaho-Wiik
R
R
Department of Internal Medicine, University of Oulu and Oulu University Hospital, Oulu, Finland.
Soini
Y
Y
Pöllänen
R
R
Pääkkö
P
P
Kinnula
V L
VL
D000230:Adenocarcinoma / Q000235:genetics / Q000378:metabolism / Q000556:secondary; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D017403:In Situ Hybridization; D008297:Male; D008654:Mesothelioma / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000378:metabolism; D010997:Pleural Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D011379:Prognosis; D012333:RNA, Messenger / Q000378:metabolism; D012334:RNA, Neoplasm / Q000032:analysis; D019063:Tenascin / Q000235:genetics / Q000378:metabolism*; D016212:Transforming Growth Factor beta / Q000378:metabolism
D014408:Biomarkers, Tumor; D009363:Neoplasm Proteins; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D019063:Tenascin; D016212:Transforming Growth Factor beta