title: IgH enhancer-mediated deregulation of N-myc gene expression in transgenic mice: generation of lymphoid neoplasias that lack c-myc expression.
abstract: We have generated transgenic mouse lines that carry one of three different constructs in which the murine N-myc gene is expressed under the control of the immunoglobulin heavy chain transcriptional enhancer element (E mu-N-myc genes). High-level expression of the E mu-N-myc transgenes occurred in lymphoid tissues; correspondingly, many of these E mu-N-myc lines reproducibly developed pre-B- and B-lymphoid malignancies. The E mu-N-myc transgene also appeared to participate in the generation of a T cell malignancy that developed in one E mu-N-myc mouse. These tumors and cell lines adapted from them expressed exceptionally high levels of the E mu-N-myc transgene; the levels were comparable to those observed in human neuroblastomas with highly amplified N-myc genes. In contrast, all of the E mu-N-myc cell lines had exceptionally low or undetectable levels of the c-myc RNA sequences, consistent with the possibility that high-level N-myc expression can participate in the negative 'cross-regulation' of c-myc gene expression. Our findings demonstrate that deregulated expression of the N-myc gene has potent oncogenic potential within the B-lymphoid lineage despite the fact that the N-myc gene has never been implicated in naturally occurring B-lymphoid malignancies. Our results also are discussed in the context of differential myc gene activity in normal and transformed cells.
authors.affiliation: Howard Hughes Medical Institute, New York, NY.
authors.forename: R
authors.initials: R
authors.lastname: Dildrop
authors.forename: A
authors.initials: A
authors.lastname: Ma
authors.forename: K
authors.initials: K
authors.lastname: Zimmerman
authors.forename: E
authors.initials: E
authors.lastname: Hsu
authors.forename: A
authors.initials: A
authors.lastname: Tesfaye
authors.forename: R
authors.initials: R
authors.lastname: DePinho
authors.forename: F W
authors.initials: FW
authors.lastname: Alt
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology; D002454:Cell Differentiation; D004742:Enhancer Elements, Genetic; D005260:Female; D005786:Gene Expression Regulation; D015321:Gene Rearrangement; D005803:Genes, Immunoglobulin; D007143:Immunoglobulin Heavy Chains / Q000235:genetics; D008223:Lymphoma / Q000235:genetics*; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D009857:Oncogenes
chemical_list: D007143:Immunoglobulin Heavy Chains