Reduced membranous and ectopic cytoplasmic expression of β -catenin correlate with cyclin D1 overexpression and poor prognosis in pancreatic cancer

✍ Scribed by Qilu Qiao; Marco Ramadani; Susanne Gansauge; Frank Gansauge; Gerd Leder; Hans G. Beger

• Publisher: John Wiley and Sons
• Year: 2001
• Tongue: French
• Weight: 292 KB
• Volume: 95
• Category: Article
• ISSN: 0020-7136
• DOI: 10.1002/1097-0215(20010520)95:3<194::aid-ijc1033>3.0.co;2-m

✦ Synopsis

␤-Catenin is a component of the E-cadherin-catenin cell adhesion complex. It plays also a role in intracellular signaling and can function as an oncogene when it binds to the T-cell factor 4 (Tcf4)-binding site in the promoter region of cyclin D1 and transactivates genes after translocation to the nucleus. We evaluated the immunohistochemical expression pattern of ␤-catenin in relationship with cyclin D1 overexpression, tumor grade, clinicopathologic parameters and patients' survival in 43 ductal adenocarcinomas of the pancreas and 5 normal pancreatic tissues. We were able to show that, both reduced membranous ␤-catenin expression (25 of 43, 58.1%) and accumulation of ␤-catenin in the cytoplasm (28 of 43, 65.1%) correlated significantly with cyclin D1 overexpression (both p < 0.0005). Furthermore, we could show a clear correlation between reduced membranous expression and ectopic cytoplasmic expression of ␤-catenin (p < 0.0005). Among patients with carcinomas showing no cytoplasmic expression, the 1-year survival was 86.6% whereas among patients with carcinomas showing cytoplasmic expression only 35.7% survived 1 year (p < 0.01). Co-precipitation experiments revealed reduced ␤-catenin bound to the E-cadherin-catenin complex in pancreatic tumor tissues compared with normal pancreatic tissues. These results suggest that ␤-catenin may be involved in the tumorigenesis of pancreatic cancer and exhibited its effects mainly by the transactivation of cyclin D1.