动物造模,药效评价,白血病 z-bio 2024-09-04 407

　　[Modeling mechanism] bcr/bl transgenic mouse model: Through cloning and analysis of the promoter sequence and function of the mouse Tec gene, it was found that genes regulated by the Tec promoter were only specifically expressed in the cytoplasm of hematopoietic stem cells. Using the promoter sequence of the mouse Tec gene, a transgenic vector was prepared carrying the leukemia related gene ber/bl to create a transgenic animal. Transgenic mice first exhibit abnormal proliferation of granulocytes and high thrombocytopenia, and after a certain period of time, develop myeloproliferative syndrome, which is very similar to human CML. Among them, some genetically modified mice showed acute leukemia at birth, but their offspring developed myelodysplastic syndrome after a latent period. Another type of transgenic mouse is the highly expressed and continuously activated mutant Stats, which carries two mutation sites and can bind to endogenous Stat5 to form a dimer for sustained activation. This type of mouse develops leukemia during its growth and development process. There is also a knock in model for mutant genes. For example, SHP-2D61G and SHP-2E76K gene knockout mice both developed leukemia.

　　Several transgenic mouse strains capable of simulating human CML have been established using different promoters. Compared with the CML model established by retroviral transfection and transplantation, the transgenic mouse model has the following advantages: ① The bcr/bl gene, as a part of transgenic mice, is expressed in vivo, which can more accurately simulate human CML; The CML model established by retroviral transfection and transplantation is influenced by many cytokines during cell culture and transplantation, which, along with other factors affecting the phenotype of the disease in recipient mice, have a significant impact The bcr/bl transgenic mice can be passaged, while the CML model established by retroviral transfection and transplantation method needs to be re established The transgenic CML model has a certain latency period, which is very similar to human CML; The CML model established by reverse transcription virus transfection and transplantation has a short latency period, which is not conducive to the study of the pre pathogenesis mechanism of human CML The CML of transgenic mice has monoclonal characteristics similar to human CML, while the CML of mice transfected and transplanted with retroviruses is polyclonal. Transgenic CML also has some drawbacks: ① Every cell in transgenic animals expresses the bcr/bl gene, while human CML is only expressed in hematopoietic stem cells and progenitor cells, which may affect the pathological characteristics and treatment of CML; ② SHP-2D61G mice only develop myeloproliferative disease during normal growth and development, but leukemia and other tumors occur after irradiation SHP-2E76K is a conditional knock in mouse. If SHP-2E76K mutation is expressed in the blood system of embryonic mice, it can cause embryonic death. Therefore, Poly I: C is only used to induce Cre expression in the blood system of mice after birth, leading to the expression of SHP-2E76K mutation protein in hematopoietic stem cells or progenitor cells, and causing leukemia in mice.

　　Due to the shortcomings of the bcr/bl transgenic mouse model, such as insufficient genetic stability and imprecise imitation of CML, it is necessary to search for more suitable promoters, explore more convenient transgenic animal methods, and try more similar animal breeds. At present, it is mainly used for research in the following three areas: confirming whether CML is hematopoietic stem cell-derived, studying the combined effects of ber/bl genes and other related genes on leukemia, and screening therapeutic drugs. SHP-2D61G and SHP-2E76K knock in mice are good leukemia animal models, but they need to be commercialized.