The Study Of Biological Function Of DNA Far Upstream Element Binding Protein1

Since the early embryonic stage, hematopoietic process accompanys with mammalian groth, development, aging and alllife activities, until death. The abnormal differentiation of blood cells can lead to the occurrence of leukemia, which is still difficult to overcome now. Therefore, research on the differentiation, proliferation and apoptosis of blood cells is an important content of biology.Mammalian blood cells are generated in mesoderm of embryonic yolk sac at first. The developed liver and spleen are responsible for the generation of blood cells in the third and fourth month. After the seventh month, the generation transfer to the bone marrow. The multipotent stem cells in bone marrow can differentiate to single stem cells, primitive blood cells, early normoblast, rubricyte and late erythroblast in order. The nuclear in late erythroblast shrinks and is exclused. Then the cells become reticulocytes and are transfer to body. It is mature blood cells at last.We previous used the fetal liver model to research the different proteins in murine fetal liver from E9.5to E17.5, and found that FUBP1expresses differently. FUBP1called Far upstream element binding protein1, is a single stranded DNA binding protein, sometimes also can combine with the single stranded RNA. The main function of FUBP1is binding to the promoter’s upstream element FUSE of the housekeeping gene c-myc to enhance the transcription of c-myc thereby promoting the cell proliferation.As the literature reports, the embryonic E12.5-E15.5is a hematopoietic active period. And two-dimensional gel electrophoresis result showed that FUBP1expressed differentially during E9.5-E17.5. Therefore, FUBP1may be related to the process of erythroid differentiation of mouse. This paper took the mouse leukemia cell MEL as the research object to make it sure whether FUBP1is involved in the differentiation of erythroid.This paper wants to study the basic biology functions of FUBP1and the relationship between FUBP1and differentiation of erythroid cells. First of all, the expression of FUBP1in mouse fetal liver, different organizations, leukemia cells and MEL induced by inducers is detected by Western blot, to determine the expression profile of organizations, the differential expression of FUBP1in fetal liver, leukemia cells and induced cells. Then, immunocytochemistry is used to detect the subcellular localization of FUBP1in MEL. After that, shRNA is used to interfere the expression of FUBP1and c-myc to study the interaction with each other. The effection of interfering of FUBP1on cell viability and differentiaon is also researched. At last, FUBP1is used in clinical diagnosis to study whether FUBP1can be a new marker of Leukemia diagnosis.Results show:FUBP1is high expressed in E12.5-E14.5murine fetal liver compared to the E15.5-E17.5murine fetal liver, which indicates that FUBP1may participate in erythroid differentiation. The analysis of murine tissue expression pattern shows that it expresses specifically in tissues. It is highly expressing in kidney and brain, and expresses little in others. Moreover, there is no detectable FUBP1in the normal bone marrow, while high abundance of FUBP1expression in MEL, K562and HL-60cells. Thus, FUBP1may play a role in the carcinogenesis of erythriod cells. In addition, the result that FUBP1is down-regulated during the induction of SB/HMBA has also suggested that FUBP1was associated with erythroid differentiation. Western blot showed that the stable FUBP1-low-expressed MEL strain cells were successfully established. MTT assay showed that FUBP1knockdown could affect MEL cell proliferation. Benzidine staining showed that FUBP1knockdown could enhance the synthesis of hemoglobin. What is more, the expression of c-myc is down-regulated after FUBP1interfered. While the expression of FUBP1does not change after c-myc interfered.In a conclusion, FUBP1highly expresses in mouse fetal liver during hematopoiesis; FUBP1expresses specifically in different tissues, and locates at cytoplasm and the nucleus in leukemia cells; FUBP1is related to canceration;FUBP1can promote the proliferation, and can promote the differentiation of MEL cells after interfered; the interfering of FUBP1can inhibit the expression of c-myc, while the interfering of c-myc has no effection on the expression of FUBP1; The expression of FUBPI in leukemia patients’ whole blood samples is higher than that of normal human blood samples.The results of this study show, FUBP1relats to different types of differentiation of erythroid cells. It participates in the processes of fetal liver hematopoiesis, blood cell canceration and differentiation from leukemia cells to normal cells. It is hopeful to provide a new way for the diagnosis and treatment of leukemia.