Reduced membranous and ectopic cytoplasmic expression of beta -catenin correlate with cyclin D1 overexpression and poor prognosis in pancreatic cancer.
Beta-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 beta-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 beta-catenin expression (25 of 43, 58.1%) and accumulation of beta-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 beta-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 beta-catenin bound to the E-cadherin-catenin complex in pancreatic tumor tissues compared with normal pancreatic tissues. These results suggest that beta-catenin may be involved in the tumorigenesis of pancreatic cancer and exhibited its effects mainly by the transactivation of cyclin D1.
Qiao
Q
Q
Department of General Surgery, First Teaching Hospital of Beijing Medical University, Beijing, P. R. China.
Ramadani
M
M
Gansauge
S
S
Gansauge
F
F
Leder
G
G
Beger
H G
HG
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000378:metabolism*; D015153:Blotting, Western; D002462:Cell Membrane / Q000378:metabolism; D019938:Cyclin D1 / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000175:diagnosis* / Q000378:metabolism / Q000401:mortality; D011233:Precipitin Tests; D011379:Prognosis; D016019:Survival Analysis; D015534:Trans-Activators; D051176:beta Catenin
D014408:Biomarkers, Tumor; C495270:CTNNB1 protein, human; D003598:Cytoskeletal Proteins; D015534:Trans-Activators; D051176:beta Catenin; D019938:Cyclin D1