Published in Cancer Detection and Prevention 2000; 24(Supplement 1).

Expression of cadherins and catenins in human malignant mesothelioma cell lines and their effects on cell proliferation and motility

S Orecchia BSc, R LIbener BSc, F Schillaci BSc, P Betta MD

Pathology Unit, Dept Oncology, Azienda Sanitaria Ospedaliera, Alessandria, Italy,

AIM. Cadherin-catenin complexes are involved in cell-cell aggregation and morphoregulatory cell function. A change in their expression or structure leads to migratory and invasive cells. Our previous studies (ASCO Proceedings 19, 663A, 2000) demonstrated the heterogeneous expression of cadherins and catenins in human malignant mesothelioma (MM) at tissue level and in cell cultures when compared to normal mesothelium (N-cadherin +ve and &alfa; and β-catenins +ve). This investigation aimed at assessing a possible link of the abnormal expression of cadherins and catenins with the transformed phenotype. METHODS. Twelve MM cell lines, 2 of which SV40-DNA +ve by PCR, established from MM effusions. Immunostaining and Western blotting for N- and E-cadherins and &alfa;-, β- and γ-catenins. Cell proliferation assessment by direct cell counting in Burker chamber. Migration bioassay in Transwell chambers with polycarbonate filters, additionally coated with ECM gel for invasion bioassay. RESULTS. All N-cadherin +ve cell lines, once confluent, kept on proliferating, while the cell lines, in which E-cadherins were coexpressed or exclusively expressed, entered a stationary phase following confluence, in spite of a higher migration activity. No relation existed between the different cadherin and catenin immunoprofiles and the invasive potential, although the highest invasive capacity was displayed by the 2 SV40-DNA +ve MM cell lines. CONCLUSIONS. The data reported show that molecules other than cadherin-catenin complexes mediate the actin cytoskeleton changes required for MM cell motility and point to a possible role of SV40 as cofactor in MM spread.

KEY WORDS: malignant mesothelioma, cadherins, catenins , cell proliferation , cell motility.

For more information, contact

Paper presented at the International Symposium on Impact of Biotechnology on Cancer Diagnostic & Prognostic Indicators; Geneva, Switzerland; October 28 - 31, 2000; in the section on metastasis & prevention.