SSCP detection of N-ras promoter mutations in AML patients.
Activation of the N-ras gene via coding region mutations has been previously documented in 25% of patients with acute myeloid leukemia (AML). Since overexpression of normal N-ras is also transforming in vitro, the N-ras promoter of AML patients was analyzed for the presence of promoter mutations that may affect expression of the N-ras gene. Single-stranded conformational polymorphism (SSCP) was used to analyze samples from 26 AML patients and 13 normal subjects. A novel polymorphism at position 390 within the N-ras promoter was observed in both AML patients and normal samples at an overall frequency of 26%. In addition, two of 26 patients had single-base substitutions within protein binding sites that altered the binding of transcription factors to the promoter. One patient had a T-->A mutation at position 520 within an AP-1 binding site; the other had an A-->G mutation at position 409 within a protein binding region adjacent to a Myb binding site. The data suggest that in addition to coding region mutations in the N-ras gene, mutations in the promoter region that could alter regulation of N-ras expression provide an alternative mechanism of involvement of N-ras in AML.
Thorn
J
J
Kanematsu Laboratories, Royal Prince Alfred Hospital, Camperdown, NSW, Australia.
Molloy
P
P
Iland
H
H
D001483:Base Sequence; D001665:Binding Sites; D017931:DNA Primers / Q000737:chemistry; D004268:DNA-Binding Proteins / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic; D011905:Genes, ras; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000235:genetics*; D008969:Molecular Sequence Data; D017354:Point Mutation; D011110:Polymorphism, Genetic; D018807:Polymorphism, Single-Stranded Conformational; D011401:Promoter Regions, Genetic; D014158:Transcription, Genetic
D017931:DNA Primers; D004268:DNA-Binding Proteins