Correlation Between Genomic Abnormalities And Acute Myeloid Leukemia And Exploration Of Candidate Genes

Acute myeloid leukemia(AML)is a common hematopoietic malignancy,accounting for about 70%of acute leukemia.The findings of the past three decades show that the occurrence of AML is a clonal evolution process driven by different driving mutations.Genetic and epigenetic abnormalities play a role in different stages of disease,disease prognosis and clinical features.Crucial role.Based on the understanding of these mechanisms,the standard treatment regimen has improved,but the treatment strategy has not changed significantly.AML is still a disease with large prognosis and high mortality.Therefore,studying AML genome abnormalities,comprehensively understanding its pathogenesis,and exploring new related candidate genes remains an important issue in AML research.In this study,81 cases of AML were used as research objects,and high-resolution single nucleotide polymorphisms array(SNP-array)chip technology was used as a means to combine karyotype analysis and fluorescence in situ hybridization.(Fluorescence in situ hybridization,FISH),data analysis was performed by tools such as the UCSC genome database(Http://genome.ucsc.edu).The main results are as follows:1.81 AML specimens of this study ranged in age from 21 to 81 years,with an average age of 57 years.The male to female ratio is 1.69(49:29).The AML genome showed a large number of chromosome structural and quantitative abnormalities,accounting for 85.2%(69 specimens),a total of 106 times.Abnormal chromosome structure is more common than the number.In the structural abnormality,the chromosome partial deletion occurred 38 times,the partial repeat appeared 24 times,and the translocation inversion occurred 24 times.It can be seen that the incidence of partial deletion of chromosome was much higher than that of partial repetition,which was about 1.58:1.Duplications and deletions of chromosomes 1 and 14 were not found in the AML genome.The copy number alteration(CNA)detected by SNP-array chip technology only appeared 47 times(28 cases),and the<3Mb CNA appeared 43 times,of which<1Mb CNA appeared 23 times,micro-repetition and micro-replication The incidence of deletions was similar,22 and 25 respectively.Combined with age and karyotype factors,the incidence of micro CNA was higher in the group less than 60 years old(P=0.000),and microreplication was more common than microdeletion.Minimal CNAs are most common in AML patients with a moderate pro-nuclear normal group,and micro-repetitions are more than micro-deletions.SNP-array technology also revealed a copy of the random copy of heterozygosity(cnLOH),a total of 44 times,found in 30 cases of AML(37%),the most common are chromosomes 11 and 13.Combined with age and karyotype factors,cnLOH was more common in patients with<60 years of age and normal karyotype prognosis;it is worth noting that cnLOH with normal genomic copy number was not found in the better prognosis group.2.AML with del(9q)a total of 11 cases,the age of onset ranging from 21 to 73years old,the median age is 51 years old.The male to female ratio is 0.83(5:6).All patients with Del(9q)AML with t(8;21)or t(15;17)translocation achieved complete remission,and the remaining cases underwent bone marrow transplantation,2 of which were 5 months after transplantation and Complete remission(CR)was achieved in 8 months,and 5 patients died within 22 months after the initial diagnosis(12-22 months,median survival 13 months).The deletion range of AML with del(9q)was 17.9-50.2Mb,and the median size was 34.2Mb.The AML cases carrying the three largest deletion intervals were accompanied by t(8;21)or t(15;17)translocations.The proximal end of the AML with del(9q)deletion interval is located in the interval of 2.114Mb(chr9:68,838,523-70,984,372)of 9q21.11,and the distal site interval varies greatly.By comparing the missing interval of the congenital9q21.13 microdeletion syndrome with no hematologic malignancies,combined with the overall survival of the patient,we defined two common missing regions of the long arm of chromosome 9 associated with AML(Common deleted Region,CDR),CDRmin(chr9:90,590,650-97,888,730,7.3 Mb)and CDRmax(chr9:85,397,699-109,427,261,24.0 Mb).We screened a number of candidate genes that may be involved in the development and prognosis of AML,such as FANCC,GADD45G,MIR23A/B,MIR27A/B,MIRLET7A1,MIRLET7D,MIRLET7F1,ERCC6L2,TAL2 and NR4A3 genes.3.In 81 cases of AML,2 cases of inv(16)AML with 3'CBFB deletion were identified by FISH technique and SNP-array precise site.Since the 3'CBFB deletion is relatively rare,we have further reviewed the Pubmed database,and only 14 cases have been reported so far.Most of these cases were detected by karyotyping and FISH techniques for the detection of 3'CBFB deletions.In the literature,there were 3cases of precise cleavage sites using Microarray technology,and only 1 case of genomic coordinate numbers was clearly known(Dawson et al).In combination with the two patients found in this study,the 3'CBFB deletions have different breakpoints spanning hundreds to thousands of DNA bases.We first searched the Cancer Gene Census(CGC)of the Catalogue Of Somatic Mutations In Cancer(COSMIC),the CBFB and CTCF genes were located in the 16q deletion region;the MYH11 gene was located in the 16p deletion region.Case 1 received induction chemotherapy and achieved CR after 21 days.After two consolidation chemotherapy,he underwent Autologous stem cell transplant(ASCT),which has been CR for 3 years.Case 2underwent induction chemotherapy and achieved CR,and he underwent two cycles of consolidation chemotherapy,which has been CR for four years.Case 3 reported by Dawson et al also reached CR;in 13 other inv(16)AML with 3'CBFB deletion,5cases reached CR,ranging from 2 months to 42 months;the remaining Of the 8patients,3 had recurrence after CR,3 had no remission after chemotherapy,and the remaining 2 did not provide clinical data.Overall,the CR rate of inv(16)AML with3'CBFB deletion was approximately 50%(8/16).4.In 81 cases of AML genome analysis,we detected 6 cases of PML-RARA positive APL,2 of which showed karyotype analysis showing complex karyotypes of three chromosomal translocations,and the current APL prognosis with complex karyotype is still Inconclusive.Therefore,we used APL patients as the research object,and reviewed 35 other APL specimens with clinical data such as morphology,immunophenotyping,karyotype,and FLT3-ITD mutation examination.Among the41 patients with APL included in the study,there were 33 cases with classic karyotype t(15;17)and 8 complicated karyotypes with PML-RARA positive.There were 19 males and 22 females with an average age of 38(6-62)years old.WBC 8.8(0.4-45.8)×10~9/L at the time of initial diagnosis,HGB 8.53(4.4-11.8)g/dL,PLT 26.2(4-105)×10~9/L.There were no significant differences in gender,age,blood count,and PML-RARA fusion gene types between the two groups.There was no significant difference in the FLT3 mutation rate between the complex karyotype and the classical karyotype.All 41 patients with APL underwent treatment with all-trans retinoic acid and arsenic trioxide.All of the 33 patients with classic karyotype achieved CR,and 6 of 8 patients with complex karyotype achieved CR,and 2patients developed CR.Early death.During the follow-up period,the overall overall survival(OS)of the classic karyotype and complex karyotype patients were 20months and 18 months,respectively,and the difference was not statistically significant.5.In this study,a total of 106 genetic abnormalities were found in the three detection techniques.The agreement rate between SNP-array and karyotype analysis was 28%;the copy number anomaly found only by SNP-array technique appeared47 times,accounting for 44 times;only chromosomal translocation and inversion of chromosomal karyotyping techniques were found 24 times,accounting for 23%;and3 specimens were detected,and FISH technique detected low levels of abnormalities not detected by karyotype analysis and genomic hybridization techniques.In 81AML genomes,SNP-array detected karyotype analysis and genetic abnormalities not detected by FISH in 56%(45 patients)of the subjects.Therefore,a single technology cannot comprehensively and accurately evaluate the AML genome.SNP-array technology combined with traditional karyotype analysis and FISH technology can obtain a complete genetic abnormality of the genome,which is a comprehensive and inexpensive AML genome analysis.A reliable way.In this study,high-resolution SNP-array chip technology was combined with FISH and traditional karyotype analysis techniques to analyze AML genomic genetic abnormalities.Based on the obtained AML chromosome structure and quantitative abnormal data,AML genomics genetics was drawn.Abnormal maps,it is not uncommon to find micro-CNA,and it is related to clinical phenotype.The genes related to the development of AML are screened,which provides a theoretical basis for the pathogenesis,prognosis and precision treatment of AML.The appearance of3'CBFB microdeletions and complex karyotypes in inv(16)AML and PML-RARA-positive APL may not alter the prognosis of these two better AML subtypes.