Mouse Myelomonocytic Leukemia Model And Experimental Research Related To Leukemia Gene Expression

Objective: The aim of this study is to establish mice myelomonocytic leukemia model by intravenous injection of the WEHI-3 myelomonocytic leukemia cells into normal BALB / c mice, and to further explore the biological characteristics. By detecting the expression level of differentiation inhibitory factor nm23-M1 gene and c-myc gene, we analyze the role of these two genes in mice myelomonocytic leukemia.Methods: 1 The normal BALB / c mice were injected with WEHI-3 myelomonocytic leukemia cells,then we detected the biological characteristics of mice myelomonocytic leukemia through the count and classification of peripheral WBC, the number of leukemia cells in BM, flow cytometry, histopathologically examined the mouse.2.we examined the levels of nm23 expression in bone marrow of leukemia groups and normal control groups. Differences between groups were evaluated by Mann-Whitney's U-test, and P value indicated a significant difference(p<0.05).Result: 1. When the normal BALB / c mice were administrated intravenously at the doses of 1×104～1×107 WEHI-3 myelomonocytic leukemia cells , none of the mice suffered from leukemia. However, when the mice were administrated intravenously at the dose of 1×104～1×107 WEHI-3 myelomonocytic leukemia cells, the incidence of leukemia was 100 percent. The survival time was related to the dose of WEHI-3 myelomonocytic leukemia cells. The number of white blood cells increases gradually and it could reach as high as 5 ~ 20 times more than normal in late period. The ratio of neutrophils in peripheral blood raised gradually while the ratio of lymphocytes decreased. About 5～20% the leukemia cells were found on peripheral blood smear at late period.2. The leukemia cell infiltration was observed in liver, spleen, brain, lung and bone marrow, particularly hepatosplenomegaly. 3. Flow cytometry examine: The MAC3 of WEHI-3 cells was at a high level.4. Chromosome of most Leukemia mice was hyperdiploid karyotype and the number was between 71 and 77.5. 3 days after injecting WEHI-3 myelomonocytic leukemia cells at the dose of 106, the mice were administrated at dose of 200mg/kg Cy, we found that the survival time of mice were lengthened. The residual leukemia cells in vivo can lead to relapse. It can be used as a state of minimal residual leukemia.6. Analyzed by Mann-Whitney's U-test, nm23-M1 gene expression was significantly higher in leukemia group(Z=-5.343,P<0.05).7. we determined the correlation of nm23-M1 gene expression level with age, sex, white blood cell count, primitive bone marrow cells and organ invasion of leukemia cells. We found that nm23-M1 gene expression is related with white blood cell count, primitive bone marrow cells and organ invasion of leukemia cells but not age or sex.8. No group differences were found for c-myc gene expression(Z=-0.990,P>0.05).Conclusion: 1.Intravenous injection of the WEHI-3 myelomonocytic leukemia cells into normal BALB / c mice successfully induced the systemic disseminated myelomonocytic leukemia in these mice. It is a good model for drug research,bio-oriented treatment and gene therapy.2. Out of control proliferation, differentiation obstacles and abnormal apoptosis of leukemia cell are closely related to abnormal expression of genes. nm23-M1 gene expression is greatly increased in myelomonocytic leukemia mice, and there is a correlation between nm23 function and malignant phenotypes in leukemia. Therefore, we apply nm23 gene as a prognostic factor in myelomonocytic leukemia.3. c-myc gene expression was not related with myelomonocytic leukemia.