Jayaraman Bhaskar, Valiathan Gopalakrishnan Mohan, Jayakumar Keerthivasan, Palaniyandi Arunmozhi, Thenumgal Siji Jacob, Ramanathan Arvind
Department of Periodontia, Sree Balaji Dental College and Hospital, Bharath University, Narayanapuram, Chennai, India.
Asian Pac J Cancer Prev. 2012;13(11):5535-8. doi: 10.7314/apjcp.2012.13.11.5535.
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.
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.
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.
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.
有病例报告称，抗癫痫药物苯妥英钠引起的牙龈过度增生可引发口腔鳞状细胞癌。然而，迄今为止，尚未对苯妥英钠诱导的牙龈过度增生组织中癌症中最常发生突变的两个基因——p53和ras基因的突变情况进行详细分析。
使用针对p53（外显子5 - 8）和H - ras（外显子1 - 2）基因的引物，对从接受苯妥英治疗的患者收集的20个牙龈过度增生组织中分离出的细胞DNA进行扩增。然后对PCR扩增产物进行凝胶纯化，并进行直接测序分析以筛选突变。
对20个苯妥英诱导的牙龈增生样本进行直接测序，未在分析的p53和H - ras基因的任何外显子中发现突变。
我们的结果表明，p53和H - ras基因的突变改变在苯妥英诱导的牙龈增生中并不常见，这表明这种病理状况具有非恶性性质。本研究的结果具有临床意义，因为大量癫痫患者接受苯妥英治疗。
