C. Trivedy et al., P53 ABERRATIONS IN ORAL SUBMUCOUS FIBROSIS AND ORAL SQUAMOUS-CELL CARCINOMA DETECTED BY IMMUNOCYTOCHEMISTRY AND PCR-SSCP, Journal of oral pathology & medicine, 27(2), 1998, pp. 72-77
An archival series of oral biopsies from Karachi, Pakistan, consisting
of 21 cases of oral submucous fibrosis (OSF) and 27 cases of squamous
cell carcinoma (SCC), of which 6 had arisen from OSF, were used to ex
amine the aberrations in the structure and expression of the p53 tumou
r suppressor gene. The PCR-SSCP method was used for mutation analysis
of exons 2-9, and (over)expression of p53 protein was detected by immu
nocytochemistry using monoclonal antibody DO 7. Positive immunostainin
g was observed in 15/20 (75%) of OSF specimens, 3/6 (50%) of SCC arisi
ng from OSF and 14/21 (67%) of SCC not arising from OSF. Mobility shif
ts in SSCP indicative of a mutation in p53 or loss of heterozygosity (
deletion of a band) were seen in 13/21 cases of OSF and 15/27 cases of
SCC. There was concordance between immunocytochemistry and SSCP resul
ts in a majority (33/48) of samples. Though the number of analysed SCC
cases arising from OSF was limited, the results suggest that p53 muta
tion/protein stabilisation may play a part in the pathogenesis of OSF
and its progression to SCC.