Deletion Of DCC Gene Promotes Malignant Transformation Of Hemopoietic Cells With Positive P230～(Bcr/Abl) Expression

PurposeThe genesis of carcinoma is related to several oncogenes and anti ?onco-genes which take part in the formation of malignant phenotype of carcinoma. Activation of oncogenes promotes the malignant transformationof cells and causes the occurrence of carcinoma. Inactivation of anti - oncogene will cause uncontrolled growth and differentiation of cell and lead to malignant proliferation of cells.Investigations have showed that malignant diseases of hematopoietic organs, such as chronic myelogenous leukemia (CML) and Ph (Philadelphia) positive acute leukemia are related to oncogenes such as c - abl, ras, c - myc and anti - oncogenes such as P53 and RB. To investigate the effect of oncogenes and anti -oncogenes on the course of leukemia genesis, mice of P230Bcr/AblTg/- and DCC heterozygous deletion (DCC +/ - )were matched, and produced P230Bcr/ AblTg/mice-,(DCC +/-)mice,Bcr/AblTg/-x(DCC + /- )mice,Bcr/Abr-/x (DCC + / + ) normal mice. Phenotype and molecular biological behavior of leukemia was investigated in vivo in order to explore the mechanism of leukemia genesis.Materials and MethodsI. Materials1. Mice Mice of P230Bcr/AblTg/- and DCC heterozygous (DCC +/ - ) were matched, and produced P230Bcr/AblTg/mice-,(DCC + / - )mice,Bcr/AblTG-x(DCC +/ - )mice,Bcr/Abl-/-x(DCC +/ + )normal mice.2. Main reagent : dilution fluid, hemolysis fluid, Bcr/Abl(P230) , primer and probe of GAPDH gene, primer of DCC gene, RNA extracting fluid, cDNA kit.3. Main instruments: LC - 152 automatic blood cells counting meter (Japan) , GeneAmpR 9700 PCR amplifier (American) , GeneAmpR 5700 continuous detecting system (GeneAmpR 5700 Sequence Detection System) (American ) , analysis software provided by Applied Biosystems company (Japan) , Bio -radelectrophresis apparatus, ultraviolet speetrophotometer ( Schimadzu UV -1201 Japan)II. MethodsFrom 5 months after being born, detect WBC, PLT, RBC, Hb and the percent of neutrophilic granulocytes of peripheral blood. Observe the change of pathological histology under light microscope and count the total number of megakaryocyies of spleen. Detect p230Bcr/Abl transfection gene expression with PCR technique.Results1. After continuous observation for 18 months, proliferative myelogram appeared and platelet increased prominendy, white blood cell increased slighdy, the ratio of neutral lobocytes increased in the peripheral blood with mild anemia at the 15th month after born. The spleens were infiltrated by neutral lobocyes. There' s no abnormity in other tissues and organs.2. In (DCC +/- ) mice, the platelet increased prominendy at the 13th month after .born, as well as mild anemia, increase of neutral lobocytes rado were observed. White blood cells were normal. The spleens were tumescent widi megakaryocyte and neutral lobocytes infiltration. There s no abnormal changes in odier dssues and organs.3. In P230Bcr/AblTg/-x DCC + / - -mice, the WBC, ratio of neutral lobocytes and PIT were increased with mild anemia from 11 mondis after bor. The spleens were tumescent with megakaryocyte and neutral lobocytes infiltration.There' s no abnormal changes in other tissues and organs.4. The expression of transfection genes was high in spleen, and secondly in bone marrow, liver and thymus gland.Conclusion1. P230Bcr/AblTg/mice, ( DCC +/ - ) mice, Bcr/AblTg/-x( DCC +/ - ) mice were all developed to MPD. Bcr/AblTg/-x( DCC + / - )mice were earlier than P230Bcr/AblTg/ .-mice and( DCC + / - ) mice by 2 ~4 months in the time of illness onset.2. The genetic background and phenotype of ( p230) Bcr/Abl transgenic mice will provide biological models to investigation in vivo of chronic myelocytic leukemia, the mechanism of its acute change, and the development of therapeutic drugs for PH positive leukemia including immunotherapy.3 The effect of both activation of Bcr/Abl oncogenes and deletion of DCC anti - oncogenes accelerates the malignant changes of hemopoietic cells, which proves that as an anti - oncegene, DCC gene plays and important role in...