OBJECTIVETo establish a novel Myc gene transgenic mouse model for spontaneously forming B-lymphoma and assessing its tumorigenesis potential.

METHODSFreshly isolated hematopoietic progenitor cells served as the target for Myc gene transfer mediated by a retrovirus vector. These cells were engrafted into C57BL/6 mice with (60)Co-gamma ray radiation in advance. Tumor latency was measured and the tumor loaded mice were followed for survival time. Tumor was identified with histology and immunostaining. The exogenous Myc gene was detected by Western blot (in liver, spleen, tumor tissue) and flow cytometry (FCM) \[in bone marrow (BM)\].

RESULTSMice BM-infected with mutant Myc gene more readily gave rise to B-cell lymphomas than those infected with wild type Myc gene did Myc gene was expressed highly in BM and tumor tissues but not in liver and spleen.

CONCLUSIONOur model will be a tool in assessing the transforming potential of Myc mutants and in studying cooperation between Myc and other oncogenes. Mutant Myc is more effective than wild-type Myc in promoting B cell lymphomagenesis in mice.