title: Lack of mutations in protein tyrosine kinase domain coding exons 19 and 21 of the EGFR gene in oral squamous cell carcinomas.
abstract: BACKGROUND
  The epidermal growth factor receptor (EGFR) plays a vital role in the activation and inactivation of receptor tyrosine kinases. Mutations in exons 19 and 21 of EGFR are commonly found to be associated with non small cell lung carcinoma and triple negative breast cancer, enhancing sensitivity to EGFR targeting chemotherapeutic agents. Since amplification and prolonged activation of EGFR molecules have been identified in oral squamous cell carcinomas (OSCC), we investigated whether OSCCs carried mutations in exons 19 and 21 of EGFR to their incidence.
  
  
  METHODS
  Tumor chromosomal DNA isolated from forty surgically excised oral squamous cell carcinoma tissues was subjected to PCR amplification with intronic primers flanking exons 19 and 21 of the EGFR gene. The PCR amplicons were subsequently subjected to direct sequencing to elucidate the mutation status.
  
  
  RESULTS
  Data analysis of the EGFR exon 19 and 21 coding sequences did not show any mutations in the forty OSCC samples that were analyzed.
  
  
  CONCLUSIONS
  To the best of our knowledge, this is the first study to have investigated the genetic status of exons 19 and 21 of EGFR in Indian OSCCs and identified that mutation in EGFR exon 19 and 21 may not contribute towards their genesis. The absence of mutations also indicates that oral cancerous lesions may not be as sensitive as other cancers to chemotherapeutic agents targeting EGFR.
authors: Human Genetics Laboratory, Sree Balaji Medical and Dental College and Hospital, Bharath University, Narayanapuram, Pallikaranai, Velachery Main Road, Chennai, India E-mail : drarvindram@yahoo.co.in.
authors: Dhaval Tushar
authors: DT
authors: Mehta
authors: Thangavelu
authors: T
authors: Annamalai
authors: Arvind
authors: A
authors: Ramanathan
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000235:genetics*; D004273:DNA, Neoplasm / Q000235:genetics*; D005091:Exons / Q000235:genetics*; D018773:Genes, erbB-1 / Q000235:genetics*; D006801:Humans; D009062:Mouth Neoplasms / Q000235:genetics*; D009154:Mutation / Q000235:genetics*; D011505:Protein-Tyrosine Kinases / Q000235:genetics*
chemical_list: D004273:DNA, Neoplasm; D011505:Protein-Tyrosine Kinases