calpain and Retroperitoneal-Neoplasms

Peritoneal dissemination and retroperitoneal lymph node involvement are main routes for tumour spread of epithelial ovarian cancer (EOC), possibly determined by the intercellular connecting protein E-Cadherin (E-Cad) and its fragments.. Tumour tissue of 105 advanced EOC patients was evaluated for protein expression of E-Cad, β-Catenin and Calpain by western blotting and immunohistochemistry. Expression patterns were compared between tumours with solely intraperitoneal (pT3c, pN0; n=41) and tumours with retroperitoneal metastases (pT1a-3c, pN1; n=64). Lysates of the EOC cell line SKOV3 and tumour tissue from the intraperitoneal group were tested for E-Cad expression following Calpain treatment.. E-Cad full-length (E-Cad-FL, 120 kDa) and two major fragments at 85 kDa (E-Cad-85) and 23 kDa (E-Cad-23) were detected by western blotting. E-Cad-85 expression was significantly higher in tumours with solely intraperitoneal metastases and correlated strongly with E-Cad-23 and the protease Calpain. Calpain-mediated cleavage was identified as a potential mechanism to generate E-Cad-85 from E-Cad-FL by treating lysates from SKOV3 cells and tumour tissue with this enzyme. Increased cytoplasmic localisation of β-Catenin in tumours with high E-Cad-85 expression corroborates that E-Cad-85 loses the binding site for β-Catenin after fragmentation, enabling tumour cluster formation and peritoneal dissemination.. Calpain-mediated E-Cad fragmentation appears to promote intraperitoneal EOC progression. Understanding these mechanisms might eventually lead to new tailored subtype-specific diagnostic and therapeutic interventions.

Topics: Adult; Aged; Aged, 80 and over; beta Catenin; Blotting, Western; Cadherins; Calpain; Carcinoma, Ovarian Epithelial; Cell Line, Tumor; Female; Humans; Immunohistochemistry; Lymph Nodes; Middle Aged; Neoplasms, Glandular and Epithelial; Ovarian Neoplasms; Peptide Fragments; Peritoneal Neoplasms; Retroperitoneal Neoplasms; Retroperitoneal Space; Retrospective Studies