Expression And Significance Of EBF-1 Gene In Acute Leukemia Ponatinib As Salvage Therapy In Relapse Chronic Myeloid Leukemia With T315I Mutation After Allogeneic Stem Cell Transplantation

Expression and significance of EBF-1 gene in acute leukemiaBackground:Acute leukemia(AL)is a common malignant tumor of the blood system.Due to the malignant cloning of hematopoietic stem cells,cell proliferation,apoptosis and developmental disorders.There is a high incidence in adult blood tumors.Early B-cell factor-1(EBF-1)is a nuclear transcription factor required for B cell development and is abundantly expressed in Progenitor B cells.The expression of EBF-1 gene is also reduced as B cells mature.When Progenitor B cells differentiated into plasma cells,the expression of EBF-1 gene disappeared.At the same time,the lack of EBF-1 gene will also lead to the developmental arrest of B cells,which will stay in the progenitor B cell stage.Obviously,the EBF-1 gene is closely related to acute B lymphocytic leukemia(B-ALL).However,the expression and role of the EBF-1 gene in B-ALL is unknown,and the study on whether it is expressed in T-cell leukemia(T-ALL)and acute myeloid leukemia(AML)is in a blank stage.In summary,this study will divide AL patients into three stages:initial development,remission,and relapse,and explore how the EBF-1 gene is expressed along with the progression of AL.Whether the expression of EBF-1 is associated with prognosis in AL patients at initial stage.The relationship between EBF-1 gene expression and minimal residual disease(MRD),and whether it is also expressed in acute T-lymphocytic leukemia and acute myeloid leukemia.Objection:1.To detect the expression of EBF-1 gene in myeloid tumor cells,using cell lines to verify whether EBF-1 gene is expressed in myeloid cells.2.To detect the expression levels of EBF-1 gene in ALL and AML patients with initial,remission and relapse stages,and to investigate the expression and clinical significance of EBF-1 gene in AL;3.To detect the expression of EBF-1 gene in MRD(-)and MRD(+)patients with bone marrow remission,and explore the consistency of EBF-1 gene with MRD;Methods:Sixty-five patients with acute leukemia and 30 healthy volunteers were included in this study.Flow cytometry and real-time PCR were used to detect the expression of EBF-1 gene in acute leukemia patients and cell lines.Statistical analysis:SPSS 22.0 statistical package was used for analysis.Results:1.The expression of EBF-1 was also detected in B cell line:U2932,Riva;myeloid cell line:HL-60,Kg-1α as well as T cell lines:Jurkat and Loucy.2.In patients with ALL and AML,EBF-1 gene expression was observed.The expression of the EBF-1 gene in B-ALL was slightly higher than in T-ALL and AML patients;3.The expression of EBF-1 gene was detected in myeloid tumor cells CD33,CD117,and stem progenitor cell CD34;4.The expression levels of EBF-1 gene at protein level and mRNA level are different in the initial,the remission,the relapse and the control groups.The expression of EBF-1 gene was significantly higher than the control group(P<0.001).The expression of EBF-1 gene in AL patients after remission was significantly lower than that at the initial stage(P<0.001).The expression level was higher than that of the normal control group(P<0.001)and the remission group(P<0.001),but it was not statistically significant with the initial group;5.Among the 51 patients who achieved bone marrow remission,they were divided into 12 cases of MRD(+)group,and 39 cases of MRD(-)group.The expression of EBF-1 gene in MRD(+)group was significantly higher than that in MRD(-)group(P<0.001).Conclusion:In this study,we found that the expression of EBF-1 gene in various cell lines and acute leukemia patients showed that:1.The expression of the EBF-1 gene was not only detected in the B cells,but detected in the myeloid cells.2.EBF-1 gene was expressed in both AML and ALL patients,and the expression of EBF-1 gene in B lymphoblastic leukemia is higher than that in T-lymphocytic leukemia and acute myeloid leukemia;3.EBF-1 gene is up-regulated in patients with newly diagnosed acute leukemia,which is significantly higher than that of healthy hematopoietic stem cell donors and bone marrow remission patients;4.The level of EBF-1 gene expression is closely related to MRD.In patients with positive MRD results,the expression level of EBF-1 gene is higher than the patients with negative MRD results;ponatinib as salvage therapy in relapse chronic myeloid leukemia with T315I mutation after allogeneic stem cell transplantationBackground and objection:Chronic myeloid leukemia(CML)is a malignant clonal disease originating from hematopoietic stem cells.It is inherited by t(9;22)(q31;qll)chromosome(Ph chromosome)ectopic and BCR/ABL fusion gene.Targeted drugs-Tyrosine kinase inhibitors(TKIs)are the first-line treatment of newly diagnosed CML today,and allogeneic hematopoietic stem cell transplantation(allo-HSCT)is only an option for inlerable,resistant or advanced CML treatment of TKIs.BCR/ABL gene mutation is the most important cause of CML resistance to TKIs and treatment failure.T3151 mutation is a very common mutation in BCR/ABL gene mutation,and it is resistant to first and second generation TKIs.For T315I mutation patients,especially those who are advanced in the transplantation,are not ideal even with allo-HSCT.Some clinical studies have shown that ponatinib as a third-generation TKIs has a good effect on patients with T315I mutations.This article retrospectively analyzes the efficacy of ponatinib in salvage treatment of T315I mutation chronic myeloid leukemia(CML-T315I)after allogeneic hematopoietic stem cell transplantation(allo-HSCT).Materials and methods:Twelve CML-T315I patients(10 had T315I mutation before transplantation and 2 cases showed T315I mutation at the time of relapse after transplantation)were included in this retrospective analysis.Ponatinib was used as single agent or combined with chemotherapy and/or donor lymphocyte infusion.The samples obtained for RTQ-PCR were also analyzed for the BCR-ABL1 mutation by direct sequencing.Scanning of the ABL KD(amino acids 219-506)for the presence of mutations was sequenced by Sanger.Results:A total of 12 patients with relapse after transplantation,2 patients with molecularrelapse treated with only single-agent ponatinib,among 10 patients with hematologic relapse,1 patient treated with single-agent ponatinib and 3 patients were given ponatinib combined with donor lymphocyte infusion(DLI),the remaining 6 patients were treated with ponatinib combined with chemotherapy and DLI.After the treatment with ponatinib,11 patients had a good response,10 patients obtained complete hematologic remission(CHR),1 patient with partial hematologic remission(PHR)and 1 patient with no response(NR);cytogenetic response was 10 patients obtained completecytogenetic response(CCyR),1 patient with partial cytogenetic response(PCyR)and one patient had no cytogenetic response;the molecular biological response was 9 patients with complete molecular response(CMR),1 patient obtainedmajore molecular response(MMR)and 2 patients with no molecular biological response.The median time to obtain CHR was 36 d(29-96)d,the median time to obtain CCyR was 63 d(32-127)d,and the median time to obtain CMR was 89 d(27-152).The median follow-up time after treatment with ponatinib was 598(range,93-1470)days,9 patients survived and 3 died.Causes of death included leukemia relapse(n=2)and ineffective treatment(n=1).The 2-year overall and disease-free survival after relapse of the 12 patients were 75.0±12.5%and 31.7±14.9%,respectively.Conclusion:This small sample data suggested that ponatinib as salvage therapy had a good response to the relapse CML-T315I after allo-HSCT.