Lack of Mutation in p53 and H-ras Genes in Phenytoin Induced Gingival Overgrowth Suggests its Non Cancerous Nature

Background: There have been case reports of oral squamous cell carcinoma arising from gingival overgrowthinduced by phenytoin - an antiepileptic drug. However, a detailed analysis for the presence of mutations in p53 andras genes, which are the two most frequently mutated genes in cancers, in phenytoin induced gingival overgrowthtissues has hitherto not been performed.
Methods: Cellular DNA isolated from twenty gingival overgrowth tissuescollected from patients undergoing phenytoin therapy were amplified using primers for p53 (exons 5-8) andH-ras (exons 1-2) genes. The PCR amplicons were then gel purified and subjected to direct sequencing analysisto screen for mutations.
Results: Direct sequencing of twenty samples of phenytoin induced gingival growth didnot identify mutations in any of the exons of p53 and H-ras genes that were analyzed.
Conclusion: Our resultindicates that mutational alteration of p53 and H-ras genes is infrequent in phenytoin induced gingival growth,which thus suggests a non malignant nature of this pathology. The findings in the present study are clinicallysignificant as a large number of epileptic patients are treated with phenytoin.