Mutation analysis of the N‐ras proto‐oncogene in active and remission phase of human acute leukemias

Abstract

DNA isolated from blood or bone-marrow samples from 18 patients with acute non-lymphocytic leukemia (ANLL) and 14 patients with acute lymphocytic leukemia (ALL) was analyzed for the presence of mutations in the N-ras gene. Using synthetic oligonucleotide probes we detected mutations in 5 cases of ANLL; 4 GGT----GAT transitions in codon 12 and one CAA----AAA transversion in codon 61. One case exhibited homozygosity for the mutation. No mutations could be detected at these codons in the DNA of the 14 ALL patients. In a follow-up study with 3 of the above 5 patients, the mutation could no longer be detected in 2 cases following successful induction of clinical remission by chemotherapy. However, the mutated N-ras persisted in one patient who did not achieve remission. We show that oligonucleotide hybridization is a sensitive assay for the detection of N-ras point mutations, which in ANLL could be used to follow the fate of the leukemic clone during (and after) therapy.

A v-H-ras-dependent hemopoietic tumor model involving progression from a clonal stage of transformation competence to autocrine interleukin 3 production.

“…Earlier studies from our laboratory (23,47,53) and others (8,19,39) showed that mutated ras genes are frequently detected in human hemopoietic malignancies. These mutations may appear either early (28) or late (20, 47a) in the development of the disease.…”

Covalently bound VirD2 protein of Agrobacterium tumefaciens protects the T-DNA from exonucleolytic degradation.

“…Single-stranded oligonucleotide probes were 32P-labeled by using T4 polynucleotide kinase (Boehringer Mannheim) (26). Hybridization 'to oligonucleotide probes was as described (27).…”

Ras oncogene expression and DNA content in plasma cell dyscrasias: a flow cytofluorimetric study

“…The usual techniques for studying oncogene structure and/or function include blotting studies of DNA or of its RNA message and investigation of the biochemical function of protein products. Immunoblotting studies indicate that ras genes are probably involved in (normal) growth control (Shih & Weeks, 1984;McGrath et al, 1984;Sweet et al, 1984;Bar-Sagi, 1989) and that their alteration plays a role in causing several types of human haematological and solid tumours (Viola et al, 1985;Thoret et al, 1984;Lundy et al, 1986;Thein et al, 1986;Liu et al, 1987;Bos et al, 1987;Senn et al, 1988;Pedersen-Bjegard et al, 1988;Hirai et al, 1988).…”