title: Reduced expression of cyclin-dependent kinase inhibitor p27(Kip1) in oral malignant tumors.
abstract: p27(Kip1), a cyclin-dependent kinase (CDK) inhibitor, blocks progression from the G(1) to S phase by binding cyclin E-CDK2 and inhibiting their activities. We studied the expression of p27 in oral tumors by immunohistochemistry to determine whether lack of p27 plays a role in the development and progression of oral cancer. Reduced expression of p27 was detected in 86% of the squamous cell carcinomas and 95% of the mucoepidermoid carcinomas, respectively, while p27 expression was well preserved in the pleomorphic adenomas. The expression of p27 showed an inverse correlation with the expression of cyclin E in the squamous cell carcinomas and mucoepidermoid carcinomas. However, there was no relationship between clinicopathological parameters and p27 expression. These results suggest that the reduction of p27 protein may confer the development of oral squamous cell carcinoma and mucoepidermoid carcinoma partly through the increased expression of cyclin E.
authors.affiliation: Department of Oral Pathology, Osaka University Faculty of Dentistry, Osaka, Japan.
authors.forename: R
authors.initials: R
authors.lastname: Ito
authors.forename: W
authors.initials: W
authors.lastname: Yasui
authors.forename: Y
authors.initials: Y
authors.lastname: Ogawa
authors.forename: S
authors.initials: S
authors.lastname: Toyosawa
authors.forename: E
authors.initials: E
authors.lastname: Tahara
authors.forename: N
authors.initials: N
authors.lastname: Ijuhin
mesh_terms: D008949:Adenoma, Pleomorphic / Q000378:metabolism* / Q000473:pathology; D014408:Biomarkers, Tumor; D018277:Carcinoma, Mucoepidermoid / Q000378:metabolism* / Q000473:pathology; D002294:Carcinoma, Squamous Cell / Q000378:metabolism* / Q000473:pathology; D018797:Cell Cycle Proteins; D050760:Cyclin-Dependent Kinase Inhibitor p27; D018844:Cyclin-Dependent Kinases / Q000037:antagonists & inhibitors*; D003937:Diagnosis, Differential; D004791:Enzyme Inhibitors / Q000378:metabolism*; D006801:Humans; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D009062:Mouth Neoplasms / Q000378:metabolism* / Q000473:pathology; D009367:Neoplasm Staging; D012468:Salivary Gland Neoplasms / Q000378:metabolism / Q000473:pathology; D025521:Tumor Suppressor Proteins
chemical_list: D014408:Biomarkers, Tumor; D018797:Cell Cycle Proteins; D004791:Enzyme Inhibitors; D008869:Microtubule-Associated Proteins; D025521:Tumor Suppressor Proteins; D050760:Cyclin-Dependent Kinase Inhibitor p27; D018844:Cyclin-Dependent Kinases