Expression of a highly conserved protein, p27BBP, during the progression of human colorectal cancer

• Published in: Cancer research (Chicago, Ill.) Vol. 60; no. 3; pp. 510 - 516
• Main Authors: SANVITO, F, VIVOLI, F, GAMBINI, S, SANTAMBROGIO, G, CATENA, M, VIALE, E, VEGLIA, F, DONADINI, A, BIFFO, S, MARCHISIO, P. C
• Format: Journal Article
• Language: English
• Published: Philadelphia, PA American Association for Cancer Research 01.02.2000
• Subjects: Adenoma - chemistry; Animals; Antigens, CD - analysis; Biological and medical sciences; Carcinoma - chemistry; Carrier Proteins - analysis; Carrier Proteins - genetics; Colorectal Neoplasms - chemistry; Eukaryotic Initiation Factors; Gastroenterology. Liver. Pancreas. Abdomen; Gene Expression Regulation, Neoplastic; Humans; Integrin beta4; Intermediate Filament Proteins - analysis; Intermediate Filament Proteins - genetics; Intestinal Mucosa - chemistry; Medical sciences; Nucleolus Organizer Region - chemistry; Rabbits; Stomach. Duodenum. Small intestine. Colon. Rectum. Anus; Transcription, Genetic; Tumors; Human; Rectal disease; Carcinoma; Premalignant lesion; Tumoral tissue; Cell adhesion molecule; Gene overexpression; Tumoral marker; Malignant tumor; Adenoma; In vitro; Colonic disease; Binding protein; Integrin; Malignant transformation; Tumor progression; Rectum; Digestive diseases; Intestinal disease; Colon; Diagnosis; Nuclear protein
• ISSN: 0008-5472; 1538-7445

The highly conserved protein p27BBP is a cytoplasmic interactor of integrin beta4 expressed in epithelia. p27BBP is found in two pools: one nuclear pool enriched in the perinucleolar region, and one cytoplasmic pool. Deletion of p27BBP in yeast is lethal as a result of loss of the ribosomal 60S subunit. The aim of this study was to investigate the distribution of p27BBP in gut epithelium and its behavior during progression of human colorectal carcinomas. Results indicated that p27BBP is high in rapidly cycling cells and decreased in villous cells committed to apoptotic cell death. In dysplastic adenomas and carcinomas, p27BBP displayed a large increase of its nucleolar component that was superimposable to argyrophylic nucleolar organizing region-associated proteins and was associated with the nuclear matrix. Western blotting confirmed increased p27BBP in dysplastic adenomas and in carcinomas. In particular, p27BBP increased progressively from adenomas to carcinomas and, in the latter, was related to the tumor stage. The overexpression of p27BBP corresponded to mRNA up-regulation in carcinomas, supporting the idea of transcriptional or post-transcriptional regulation of its expression. Results suggested that p27BBP alterations are an early event in the transition from benign to malignant colorectal phenotypes and provide a novel tool in surgical pathology.