Activation of an N-ras gene in acute myeloblastic leukemia through somatic mutation in the first exon.

A transforming N-ras gene has been cloned from acute myeloblastic leukemia bone marrow cells, in parallel with the N-ras gene derived from fibroblasts of the same patient. N-ras derived from fibroblasts lacked focus-forming activity in NIH/3T3 cells, indicating that gene activation in the leukemia cells must have occurred by a somatic event. Construction of chimeric molecules between the transforming and the normal N-ras genes and subsequent biological and sequence analysis of these constructs revealed that the transforming gene was altered by a point mutation changing amino acid 12 of the N-ras protein from glycine to aspartic acid.

Monoclonal antibodies recognizing structural components of murine retroviruses including an FMR antigen on protein p12.

Monoclonal antibodies were prepared from mice and rats immunized with Friend leukaemia virus and BALB/c xenotropic virus. By immunoprecipitation of 125I-labelled and [35S]methionine-labelled viruses and by protein blotting, ten antibodies were found to react with the viral components p12, p15, p30, gp70 and p15E/p12E. A dot-immunobinding assay was found to be a reliable method to type the antibody reactivity with different murine leukaemia viruses (MuLVs).

Activation of N-ras gene in bone marrow cells from a patient with acute myeloblastic leukaemia.

Human tumour cell lines of various histological origin contain genes that can transform NIH 3T3 cells in culture. Most frequently the gene is an activated K-ras gene, more rarely an activated H-ras gene, and sometimes the recently discovered N-ras. Other transforming genes, distinct from ras, have been found in B- and T-cell leukaemias.

A multidot immunobinding assay for autoimmunity and the demonstration of novel antibodies against retroviral antigens in the sera of MRL mice.

A dot immunobinding assay procedure has been developed for autoantibodies, and has been applied to the sera of MRL lpr/lpr mice. The profiles thus obtained include assays for circulating immune complexes, and antibodies against single-stranded DNA, double-stranded DNA, ribosomes, soluble nuclear deoxyribonucleoprotein, and retroviral antigens. Part of the data was compared with ELISA results.