E-Cadherin Expression and p53 Alterations in Soft Tissue Sarcomas: A Possible Role in Epithelial Differentiation

We investigated the expressions of E- Cadherin and p53 in soft tissue tumors to determine their significance in sarcoma development and/or progression and to assess their potential correlation with epithelial features.

A total of 79 soft tissue sarcomas, including 10 tumors comprising epithelial components, were studied immunohistochemically in paraffin-embedded tissue sections. Further analysis was performed on 61 tumors by the application of a polymerase chain reaction technique and a direct sequence analysis procedure applied to exons 5 through 8 in the p53 gene.

E-Cadherin was expressed at the cell-cell boundaries in 8 (10%) tumors: 5 of grade 2 and 3 of grade 3. Of these, six (being 60% of the total of 10 tumors containing epithelial elements) contained and two did not contain histologic evidence of epithelial differentiation. Overexpression of p53 was detected in 26 (33%) samples, 7 of which demonstrated mutations in the p53 gene. No association was established between E-Cadherin immunoreactivities and p53 abnormalities. Tumor grade was found to be strongly correlated with p53 alterations (p=0.01) but not with E-Cadherin expression (p=0.09).

These data confirm a role for altered p53 in the pathogenesis of soft tissue sarcomas and suggest a possible role for E-Cadherin in the maintenance of epithelial architecture in these tumors regardless of p53 status.