title: Mutation of Ha-ras Oncogene in Rat Salivary Gland Tumors Induced by DMBA.
abstract: OBJECTIVE
  The incidence of salivary gland tumor is approximately 2% among all head and neck tumors, of which malignant cases account for only about 5%. Much research has been performed in order to clarify the mechanism of oncogene activation, however salivary gland tumors remain understudied. We performed this study in order to characterize the ras gene in these tumors.
  
  
  METHODS
  We treated white rats with 7, 12-dimethylbenz[a]anthracene (DMBA) and confirmed the occurrence of salivary gland tumors after ten to thirty weeks. Isolated genomic DNAs from tumor tissues were added to NIH 3T3 cells. In order to detect Ha-ras mutations, we performed a two-step PCR-RFLP and 7analyzed the mutated sequences.
  
  
  RESULTS
  We induced salivary gland tumors by DMBA treatment in white rats. Isolated DNAs from the tumor tissues transformed the NIH 3T3 cells. Point mutations were observed in codons 12 and 61 of the Ha-ras oncogene. The total frequency of point mutations was 13.9% in DMBA-induced salivary gland tumors in rats.
  
  
  CONCLUSIONS
  Our results demonstrate that a variety of cancers ras oncogene mutations were also found in salivary gland tumors. We confirmed that a point mutation of the Ha-ras oncogene in a DMBA-induced salivary gland tumor occurs at a frequency of 13.9%.
authors.forename: B I
authors.initials: BI
authors.lastname: Yeh
authors.forename: D P
authors.initials: DP
authors.lastname: Han
authors.forename: J H
authors.initials: JH
authors.lastname: Sohn
authors.forename: J H
authors.initials: JH
authors.lastname: Yoon
authors.forename: H A
authors.initials: HA
authors.lastname: Lee
authors.forename: S J
authors.initials: SJ
authors.lastname: Chang
authors.forename: I D
authors.initials: ID
authors.lastname: Kong
authors.forename: H W
authors.initials: HW
authors.lastname: Kim
authors.forename: J W
authors.initials: JW
authors.lastname: Choi
keywords: 7,12-dimethylbenz[a]anthracene; Ha-ras oncogene; Salivary gland tumor