title: Lack of RING finger domain (RFD) mutations of the c-cbl gene in oral squamous cell carcinomas in Chennai, India.
abstract: BACKGROUND
  In normal cells, activated epidermal growth factor receptor (EGFR) molecules are subjected to ubiquitination-mediated proteasome degradation pathway by c-Cbl, an ubiquitin ligase that checks uncontrolled proliferation. Hence expression of wild type c-Cbl molecule is essential to keep this degradation machinery in a functional state. Loss of expression or function of c-Cbl may consequently lead to sustained activation of EGFR and promote carcinogenesis, loss of function mutations in the c-Cbl gene already being reported in lung and hematopoietic cancers. However, the genetic status of c-Cbl in oral squamous cell carcinoma (OSCC) is not known. Hence in the present study we investigated the genomic DNA isolated from OSCC tissue biopsy samples for mutations in the RING finger domain coding region of c-Cbl gene, which has also been reported to be most frequently mutated in other cancers.
  
  
  METHODS
  Total genomic DNA isolated from thirty two post surgical OSCC tissue samples were amplified using primers flanking the exon 8 of c-Cbl gene that codes for the RING finger domain. The PCR amplicons were then resolved in a 1.2% agarose gel, purified and subjected to direct sequencing to screen for mutations.
  
  
  RESULTS
  The sequencing data of the thirty two OSCC samples did not identify mutations in the RING finger domain coding region of c-Cbl gene.
  
  
  CONCLUSIONS
  To the best of our knowledge, this is the first time that the genetic status of c-Cbl gene in OSCC samples has been investigated. The present data indicates that genetic alteration of RING finger domain coding region of c-Cbl gene is relatively infrequent in OSCC samples.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Meenakshiammal Dental College and Hospital, Maduravoyal, India. drarvindram@yahoo.co.in
authors.forename: Senthilnathan
authors.initials: S
authors.lastname: Rajendran
authors.forename: Rajendran Shanmugam
authors.initials: RS
authors.lastname: Muthupalani
authors.forename: Arvind
authors.initials: A
authors.lastname: Ramanathan
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000235:genetics*; D066246:ErbB Receptors / Q000378:metabolism; D014644:Genetic Variation; D006801:Humans; D007194:India; D009062:Mouth Neoplasms / Q000235:genetics*; D009154:Mutation; D059645:Mutation Rate; D050721:Proto-Oncogene Proteins c-cbl / Q000235:genetics*; D054829:RING Finger Domains / Q000235:genetics*; D017422:Sequence Analysis, DNA
chemical_list: D050721:Proto-Oncogene Proteins c-cbl; C512478:EGFR protein, human; D066246:ErbB Receptors; C067419:CBL protein, human