Correlation between p53 gene mutation, p53 protein labeling and PCNA expression in oral squamous cell carcinomas.
BACKGROUND
The prevalence of oral squamous cell carcinoma (OSCC) among the Black community in South Africa is unacceptably high. The association between p53 protein, and PCNA overexpression and the presence of p53 gene mutations was evaluated.


METHODS
One hundred and ten formalin-fixed, paraffin-embedded blocks of OSCC were selected for immunohistochemical studies for p53 protein and PCNA expression using the DO-7 and PC10 monoclonal antibodies, respectively. DNA was extracted from fifty-five blocks and exons 5 to 9 of the p53 gene were amplified with nested primers, thereafter sequencing was performed to confirm the presence of mutations detected by single stranded conformational polymorphism.


RESULTS
Fifty-six cases (51%) showed p53 expression, while fourteen mutations (25%) were detected. A significant difference was found between the PCNA index in p53 positive and p53 negative tumors while the mean PCNA index for the tumors with p53 mutations was not significantly different from the tumors without mutations.


CONCLUSIONS
No association between p53 protein overexpression and p53 gene mutations could be demonstrated.
van Heerden
W F
WF
Department of Oral Pathology, University of Pretoria, South Africa.
van Rensburg
E J
EJ
Hemmer
J
J
Raubenheimer
E J
EJ
Engelbrecht
S
S
D000328:Adult; D000368:Aged; D044383:Black People / Q000235:genetics; D002294:Carcinoma, Squamous Cell / Q000235:genetics* / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism; D005260:Female; D016158:Genes, p53; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000235:genetics* / Q000378:metabolism; D017354:Point Mutation; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism*; D017384:Sequence Deletion; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*
D018809:Proliferating Cell Nuclear Antigen; D016159:Tumor Suppressor Protein p53