Expression Of FOXN3 In Acute Myeloid Leukemia And Its Clinical Significance

Objective:Acute leukemia is a malignant hematological malignancy that originates from hematopoietic stem and progenitor cells and has a high morbidity and mortality.According to the international FAB classification,only the acute promyelocytic leukemia(APL)can achieve the clinical cure through the method of dual induction of arsenic trioxide and retinoic acid at current medical level.The remaining types of leukemia In addition to bone marrow transplantation and standard chemotherapy,there is no clear and uniform cure.Although the five-year survival rate of acute leukemia has been increasing year by year in recent years,acute leukemia remains the first and second cause of death among children and adolescents.In view of the high degree of malignancy of the disease,and the poor treatment,the medical community for the cause of acute leukemia and its pathogenesis indepth exploration is particularly urgent.Since its discovery,the FOX protein family has been able to clearly regulate various biological functions of various cells,including proliferation and differentiation of cells,DNA damage and repair,and cell metabolism.FOXN3(Forkhead N3)is a subtype of the Forkhead(FOX)transcription factor family that is widely expressed in important organs such as liver,lung,kidney,and bone marrow.In recent years,many physiological and pathological functions of FOXN3 protein have been widely concerned.It has been reported that FOXN3 plays a key regulatory role in craniofacial and eye growth in Xenopus and inactivation of FOXN3 gene can affect growth retardation in mice and developmental defects in multiple organs in facial area while increasing embryonic mouse death Rate and lethality after birth.At the cellular level,FOXN3 was first found in yeast as a checkpoint inhibitor that regulates the biological behaviors of many transcription factors and oncogenes such as E2F5,PIM2 and ZHX1,and FOXN3 was found to have transcriptional activation in testis of Drosophila effect.In recent years,FOXN3 expression disorder has been found in various malignant tumors,but its specific mechanism of action remains to be studied.In our previous study,we found a deletion of the FOXN3 gene in patients with acute leukemia,and this deletion was particularly pronounced in AML patients.FOXN3 low expression in patients with acute leukemia,we can think that FOXN3 as a tumor suppressor gene plays an important role in acute leukemia? This result provides an opportunity for us to explore the pathophysiological function of FOXN3 in the pathogenesis and development of leukemia.We will separately explore the expression of FOXN3 in AML patients and AML cell lines,as well as the possible mechanism of FOXN3 promoting the pathogenesis of leukemia.Method: 1.Bone marrow samples from patients with acute myeloid leukemia and healthy controls were collected to detect FOXN3 m RNA expression by RT-PCR.The relationship between FOXN3 and clinicopathological data was also discussed.2.Acute myeloid leukemia cell lines were cultured,RNA and protein of cell lines were extracted respectively,and the expression level of FOXN3 was verified by RT-PCR and Western blot.3.FOXN3 over-expressing virus was transfected into FOXN3-overexpressing leukemia cell lines,and the cell proliferation,apoptosis and cell cycle of leukemia cell lines after overexpression of FOXN3 gene were examined by CCK-8 and flow cytometryResults: 1.FOXN3 m RNA levels were significantly reduced in bone marrow and cell lines of AML patients.In vitro experiments,FOXN3 protein levels in AML cell lines consistent with the patient.2.The FOXN3 expression level is related to the prognosis of AML patients.3.The results of CCK-8 assay showed that the proliferation of leukemia cells was decreased after overexpression of FOXN3 gene.Flow cytometry was used to detect the cell cycle after PI staining.The overexpression of FOXN3 led to the existence of leukemia cells S phase).Annexin-V PE / 7-AAD staining was used to detect apoptosis by flow cytometry.The results showed that the apoptosis rate was significantly increased after over-expression of FOXN3 gene.Conclusion:FOXN3 protein is decreased in both acute myeloid leukemia and leukemia cell lines.Based on this conclusion,we can conclude that FOXN3 protein may serve as a novel tumor suppressor gene for acute myeloid leukemia.The level of FOXN3 expression is negatively correlated with the patient’s WBC count,which is one of the known risk factors for acute leukemia.Therefore,FOXN3 expression may be related to the good prognosis of leukemia patients.After overexpression of FOXN3 gene in AML cell lines,we found FOXN3 m RNA and protein levels increased compared with the previous expression,while reducing the proliferation activity of leukemia cells,increased apoptosis,cell cycle arrest.Combined with the above results,we can think that FOXN3 transcription factor in acute myeloid leukemia may be as a new type of tumor suppressor gene,regulating the occurrence and development of leukemia.