Research Of MN1 Gene In Myeloid Leukemia

Three chapters will be concluded in this thesis.Chapter One: Molecular and cytogenetic characterization of five myeloid leukemia patients with t(12;22)/MN1-ETV6;Chapter Two: The clinical characteristics and prognostic significance of MN1 and CD34 gene expressions in acute myeloid leukemia;Chapter Three: Evaluation of relapse by join-detection of MN1,CD34,BAALC and WT1 expression in AML patients.Chapter One: Molecular and cytogenetic characteristics of five myeloid leukemia patients with t(12;22)/MN1-ETV6Objective: Analysis the clinical and laboratory characteristics of five myeloid leukemia patients with t(12;22)(p13;q12)and MN1-ETV6/ ETV6-MN1 fusion genes.Methods: Bone marrow cells were cultured for 24 h and analyzed for standard cytogenetic R-banding.MN1 and ETV6 genes rearrangement were detected by FISH.Reverse transcription polymerase chain reaction was used to detect MN1-ETV6/ETV6-MN1 fusion genes.Results: Among 5 patients,2 had AML-M0,2 AML-M4 and 1 CMML at diagnosis.The t(12;22)(p13;q12)was a primary abnormality in 5 patients.MN1 gene rearrangement were detected by FISH in all patients and MN1-ETV6/ETV6-MN1 fusion genes were detected by RT-PCR and confirmed by direct sequencing analysis in 4 and 3 patients,respectively.Among two patients received only chemotherapy,one died with a survival of two months and another lost to follow-up after 9 months.Supporting treatment was provided for one patient and follow up was lost soon.Among two patients received allo-SCT,one died of infection following a short survival of 2 months and another was still alive after 13 months.Conclusion: t(12;22)(p13;q12)is a rare but recurrent chromosome abnormality in myeloid leukemia.We consider that t(12;22)(p13;q12)is related to a poor prognosis and allo-SCT could be valuable for patients with t(12;22)(p13;q12).However,no firm conclusions can be drawn and more patients are needed to draw a definite conclusion.Chapter Two: The clinical characteristics and prognostic significance of MN1 and CD34 gene expressions in acute myeloid leukemiaObjective: In order to investigate the clinical features and prognostic significance of CD34 and MN1 genes expression in acute myeloid leukemia patients.Methods: MN1 gene and CD34 gene expressions were measured in 337 AML cases from Apr.2013 to Sep.2016.The clinical,cytogenetic and molecular characteristics of AML with MN1 and CD34 expression were summarized.Results: 1.Compared with other AML subtypes,MN1 gene was overexpressed in AML with inv(16)(P<0.0001)and c-kit mutation(P<0.0001)and was low expressed in AML with MLL rearrangement(P=0.0003)and NPM1 mutation(P<0.0001).2.MN1 gene was co-expressed with CD34(P<0.0001)and BAALC(P<0.0001)gene.The expression of WT1(P=0.4868)and EVI1(P=0.7903)were not associated with MN1 gene.3.Compared with low MN1 expression,high expression of MN1 gene was associated with lower level of platelet(P=0.0113),LDH(P=0.0204),BM blasts(P=0.0348),FAB-M5 subtype(P=0.0060),11q23/MLL(P=0.0028)and NPM1 mutation(P <0.0001).Inv(16)(P<0.0001),bi-CEBPA(P=0.0113)and c-kit mutation(P=0.0314)were observed more frequent in high MN1 group.4.The index of MN1/CD34 was produced by the combined use of MN1 and CD34 gene expressions.High MN1/CD34 index was associated with higher level of WBC(P=0.0444),PLT(P=0.0013),M4 subtype(P<0.0001),M5 subtype(P=0.0159),inv(16)(P<0.0001),NPM1(P<0.0001)and DNMT3 A mutations(P=0.0003).M1 subtype(P=0.0254),M2 subtype(P<0.0001),t(8;21)(P<0.0001)and bi-CEBPA mutation(P<0.0001)were observed less frequent in high MN1/CD34 group.5.Overall survival was decreased in high MN1/CD34 AML patients(P=0.0058),especially in ELN favorable-risk(P=0.0222)and adverse-risk(P=0.0281)AML subtypes.Univariate analysis showed that LDH(P=0.0124),age(P=0.0003),BM blast(P=0.0453),karyotype risk stratification(P=0.0216),FLT3 mutation(P=0.0070)and high MN1/CD34(P=0.0066)had significant differences.Multivariate analysis revealed that age(P=0.0031),LDH(P=0.0026)and high MN1/CD34(P=0.0204)had significant differences.Conclusion: 1.MN1 gene is overexpressed in certain subtypes of AML.2.MN1 gene was co-expressed with CD34 and BAALC gene.3.Combine MN1 and CD34 gene could provide clinical prognosis of AML patients and may refine their molecular risk classification.Chapter Three: Evaluation of relapse by join-detection of MN1,CD34,BAALC and WT1 expression in acute myeloid leukemia patientsObjective: This study aimed to test whether a novel approach incorporating detection of MN1,CD34,BAALC and WT1 gene expression could predict AML relapse.Methods: MN1,BAALC,WT1 and CD34 gene expressions were measured in 23 relapsed AML patients from Apr.2013 to Sep.2016.Results: 1.In total AML patients,MN1(P=0.0282),CD34(P=0.0111),WT1(P<0.0001)expression in remission were lower than newly diagnosed;MN1(P=0.0040),CD34(P<0.0001),BAALC(P=0.0005)and WT1(P<0.0001)in relapse were higher than remission.2.Pairing analysis showed that 16 cases had lower MN1 expression(P=0.0150);17 cases had lower CD34 expression(P=0.0010);15 cases had lower BAALC expression(P=0.0116);23 cases had lower WT1 expression(P<0.0001)in remission compared with these at newly diagnosed.Similarly,19 cases had higher MN1 expression(P=0.0002);22 cases had higher CD34 expression(P<0.0001);18 cases had higher BAALC expression(P=0.0019);22 cases had higher WT1 expression(P<0.0001)in relapse compared with these in remission.3.Combined analysis of these four genes showed that all patients(100%,23/23)had at least two genes,21 patients(91.3%)had at least three genes and 16 patients(69.5%)had four genes higher expression in relapse than remission.4.Six patients compared these four gene with fusion genes(including ALL-AF6,AML1-ETO,CBF?-MYH11).Cases 6 and 21 showed the expression of these 4 gene were consistent with MLL-AF6.Similarly,cases 7,13 and 21 showed the expression of these 4 gene were consistent with AML1-ETO.Conclusion: The combined detection of four genes(MN1,CD34,BAALC and WT1)can be used to predict the relapse of AML,and it is in good consistent with MLL-AF6,AML1-ETO,and CBF?-MYH11.