How to prepare genetically modified leukemia animal models?
动物模型,白血病
z-bo
2020-07-31
627
[Modeling mechanism] bcr/abl transgenic mouse model: By cloning and analyzing the promoter sequence and function of the mouse Tec gene, the genes controlled by the Tec promoter are only specifically expressed in the cytoplasm of hematopoietic stem cells. I know. The promoter sequence of the mouse Tec gene is used to create a transgenic vector with the leukemia-related gene ber/abl to create a transgenic animal. Transgenic mice first developed granulocyte overgrowth and hyperthrombosis, and developed myelodysplastic syndrome after a period of time. This is very similar to human CML. Among them, the transgenic mice showed postnatal acute leukemia after a period of incubation period, while their offspring showed potential myelodysplastic syndrome. Another type of transgenic mouse is the highly expressed, continuously activated mutant Stats. This mutant stats has two mutation sites, which can combine with endogenous stat5 to form a dimer and continue to activate. Leukemia occurs during the growth and development of the mouse. There is also a knock-in model of mutant genes. For example, SHP-2D61G and SHP-2E76K knock-in mice are leukemia.
[Model Features] Several transgenic mouse strains have been established, which can use different promoters to mimic human CML. Compared with the CML model established by retroviral transfection and transplantation, the transgenic mouse model has the following advantages:
(1) The bcr/abl gene is expressed in vivo as a part of transgenic mice, which can more accurately simulate human CML. The CML model established by retroviral transfection and transplantation is affected by many cytokines during cell culture and transplantation. These cytokines and other factors have a major impact on the disease phenotype in the treatment of recipient mice.
(2) Bcr/abl transgenic mice can be passaged, but it is necessary to reconstruct the CML model established by retroviral transfection and transplantation.
(3) The transgenic CML model has a specific incubation period very similar to that of human CML, and the CML model established by retrovirus transfection and transplantation has a short incubation period. Not useful for research.
(4) The CML of transgenic mice has the same monoclonality as human CML, but the CML of mice transplanted by transfection with retrovirus is polyclonal. Transgenic CML also has some disadvantages: ①Bcr/abl gene expression is expressed in all cells of transgenic animals, while human CML is only expressed in hematopoietic stem cells and progenitor cells, which is the pathological feature of CML. And may affect treatment. -2D61G mice will develop myeloproliferative disease only during normal growth and development, but leukemia and other tumors will develop after radiation. ③SHP-2E76K is a conditional knock-in mouse. Embryonic mice cause SHP-2E76K mutation in the blood system. The embryo of mice is lethal. Therefore, the polyI:C blood system is used only after the mouse is born. Cre induces the expression of SHP-2E76K mutant protein in mouse hematopoietic stem or progenitor cells, thereby causing mouse leukemia.
[Model Evaluation and Application] The bcr/abl transgenic mouse model has shortcomings such as insufficient genetic stability and insufficient accuracy of simulating CML, so we must find a more suitable promoter. We need to find a more convenient method of transgenic animals. Approximate animal species. At present, it is mainly used in the following three studies: to confirm whether CML is derived from hematopoietic stem cells, to study the combined effect of ber/abl genes and other related genes on leukemia, and to screen therapeutic drugs. SHP-2D61G and SHP-2E76K knock-in mice are excellent animal models of leukemia, but they need to be commercialized.
