title: Lack of mutation in p53 and H-ras genes in phenytoin induced gingival overgrowth suggests its non cancerous nature.
abstract: BACKGROUND
  There have been case reports of oral squamous cell carcinoma arising from gingival overgrowth induced by phenytoin--an antiepileptic drug. However, a detailed analysis for the presence of mutations in p53 and ras genes, which are the two most frequently mutated genes in cancers, in phenytoin induced gingival overgrowth tissues has hitherto not been performed.
  
  
  METHODS
  Cellular DNA isolated from twenty gingival overgrowth tissues collected from patients undergoing phenytoin therapy were amplified using primers for p53 (exons 5-8) and H-ras (exons 1-2) genes. The PCR amplicons were then gel purified and subjected to direct sequencing analysis to screen for mutations.
  
  
  RESULTS
  Direct sequencing of twenty samples of phenytoin induced gingival growth did not identify mutations in any of the exons of p53 and H-ras genes that were analyzed.
  
  
  CONCLUSIONS
  Our result indicates 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 clinically significant as a large number of epileptic patients are treated with phenytoin.
authors: Department of Periodontia, Sree Balaji Dental College and Hospital, Bharath University, Narayanapuram, Chennai, India.
authors: Bhaskar
authors: B
authors: Jayaraman
authors: Gopalakrishnan Mohan
authors: GM
authors: Valiathan
authors: Keerthivasan
authors: K
authors: Jayakumar
authors: Arunmozhi
authors: A
authors: Palaniyandi
authors: Siji Jacob
authors: SJ
authors: Thenumgal
authors: Arvind
authors: A
authors: Ramanathan
mesh_terms: D000293:Adolescent; D000328:Adult; D000927:Anticonvulsants / Q000009:adverse effects*; D003430:Cross-Sectional Studies; D017931:DNA Primers; D004273:DNA, Neoplasm / Q000235:genetics; D005091:Exons / Q000235:genetics; D005260:Female; D019214:Gingival Overgrowth / Q000139:chemically induced / Q000235:genetics*; D006801:Humans; D008297:Male; D009154:Mutation / Q000235:genetics*; D010672:Phenytoin / Q000009:adverse effects*; D016133:Polymerase Chain Reaction; D011379:Prognosis; D016283:Proto-Oncogene Proteins p21(ras) / Q000235:genetics*; D016159:Tumor Suppressor Protein p53 / Q000235:genetics*; D055815:Young Adult
chemical_list: D000927:Anticonvulsants; D017931:DNA Primers; D004273:DNA, Neoplasm; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53; D010672:Phenytoin; C501009:HRAS protein, human; D016283:Proto-Oncogene Proteins p21(ras)