Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1999-3-11
pubmed:abstractText
Cyclins play an important role in regulating the passage of dividing cells through critical checkpoints in the cell cycle. Aberrant expression of cyclin proteins has been found in a number of human cancers, including carcinomas of the head and neck, where amplification of the cyclin D1 gene is a common finding. The objective of this study was to examine cell cycle kinetics in oral carcinomas by determining the expression of the S phase protein cyclin A and the M phase protein cyclin B1. Routinely processed tissue sections of 50 oral squamous cell carcinomas from the floor of the mouth were stained by immunohistochemistry for cyclin A, cyclin B1 and Ki-67 proteins. Ten specimens of normal epithelium from the floor of the mouth were used as controls. The number of cells showing nuclear staining for cyclin A, cyclin B1 and Ki-67 proteins was determined by computer image analysis. There were 17 well-differentiated, 25 moderately differentiated and 8 poorly differentiated tumours. Mean counts for cyclin A (29.50+/-4.10, mean+/-95% CI), cyclin B1 (2.05+/-0.30) and Ki-67 (49.46+/-5.91) proteins in the carcinomas were significantly higher than counts for the normal epithelial controls (cyclin A: 9.30+/-1.72; cyclin B1: 1.01+/-0.36; Ki-67: 17.40+/-4.17). For cyclin A, cyclin B1 and Ki-67, mean staining scores for all tumour grades were significantly higher than controls. There was a strong correlation between Ki-67 and cyclin A scores in all tumour groups (r2=0.68); however, the correlations between cyclin B1 and cyclin A scores (r2=0.35) and between cyclin B1 and Ki-67 scores (r2= 0.39) were weak. We conclude that there is overexpression of cyclin A and cyclin B1 proteins in oral carcinoma. Furthermore, the poor correlations for cyclin B1 scores with other cell cycle indices suggest that there may be aberrant cell cycle progression at the G2/M checkpoint in oral carcinomas.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
D
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0904-2512
pubmed:author
pubmed:issnType
Print
pubmed:volume
28
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
77-81
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Aberrant expression of cyclin A and cyclin B1 proteins in oral carcinoma.
pubmed:affiliation
Department of Oral Pathology, Faculty of Dentistry, University of Toronto, Ontario, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't