| 1,The ratio of expression of AML1-ETO9a isoform in Acute Myeloid Leukemia M2 subtype with t(8;21) and its clinical significanceObjectives①To study the ratio of expression of AML1-ETO9a (AE9a) isoform in acute myeloid leukemia M2 (AML-M2) subtype with t(8;21) and its clinical significance.②To explore the clinical features of AML-M2 with t(8;21)/ AML1-ETO9a. Methods①44 bone marrow samples from newly diagnosed AML-M2 with t (8;21) patients who co-expressed both AE9a and AE were firstly selected by using the qualitative reverse transcription polymerase chain reaction (RT-PCR).②Monitor the alteration of the AE9a ratio in this 44 AML-M2 with t (8;21) patients during follow-up by using quantitative real-time reverse transcription polymerase chain reaction (real-time PCR), we combine all the information with clinical features to analysis the AML-M2 patients with t(8;21)/AML1-ETO9a.Results①The expression level of AE9a was markedly lower than that of AE in 44 newly-diagnosed AML-M2 with t(8;21) patients; A positive correlation between the expression level of AE9a and AE was shown in many bone marrow samples from 44 patients during the follow-up by real-time PCR; The transcript level of both AE9a and AE decreased in 44 newly-diagnosed patients after one course of standard chemotherapy, but the percentage of expression level of AE9a increased in comparison with that untreated (P<0.05). After one course of standard chemotherapy treatment, the proportion of AE9a relative to the overall in not complete remission(CR) patients is significantly higher than that complete remission patients (P<0.05). In patients with relapse had a higher ratio of AE9a in total than the unrelapsed patients (P<0.05). In remission, the percentage of the AE9a out of the overall obviously elevated and even had an abnormal increase while the expression AE fusion gene in the low level.②According to immunophenotype profiles, 40 patients express myeloid antigen lonely, 3 patients simultaneously express myeloid and B lymphocytes department antigen, immunophenotype result was lack in 1 case. Karyotype results shown: Of the 44 AML-M2 cases, t(8;21) were detected in 17 cases (38.64%), chromosomal abnormalities in addition to t(8;21) were observed in 27 cases (61.36%). The most frequent secondary chromosome anomaly was loss of the sex chromosome, especially loss of the Y-chromosome. Of the 44 patients, the median WBC counts were 9.05(1.5-35.5)×109/L, median WBC index was 4.1, median Hb was 72.5(36-145)g/L, median PLT was 31.5(3-238)×109/L,median LDH was 395(100-1572.6)U/L. Of the 44 patients, 15 cases had lymph node, spleen and/or liver infiltration, 2 cases had central nervous system (CNS) infiltrates. In newly-diagnosed patients, the expression level of AE9a had no correlation with the high leukocyte count, high WBC index and the accompanying chromosome aberration. During the complete remission phase, the patients with high level of AE9a (≥30%) easily relapse, and their relapse rate were obviously higher than that low level group (<30%). The relapse-free survival (RFS) time of high level group(≥30%) is short(p<0.05).Conclusion①AE9a and AE co-expressed in most of the patients of AML with t (8; 21) translocation. The expression level of AE9a was lower than that of AE in a single patient. Moreover,the expression level of these two isoforms in a single patient had a distinctly positive correlation.②The standard chemotherapy sensitivity of AE9a is less than AE. t(8;21)/AML1-ETO9a positive AML-M2 had low remission rate after standard chemotherapy.③I n newly-diagnosed patients, the expression level of AE9a had no correlation with the high leukocyte count, high WBC index and the accompanying chromosome aberration.④During the complete remission phase, the patients with high level of AE9a(≥30%) tend to relapse and their RFS time are short. Monitoring the alteration of AE9a ratio during the complete remission phase can predict the early relapse of the disease compared to monitoring the alteration of AE lonely.2,The analysis of AE9a and C-KIT gene mutations in Acute Myeloid Leukemia M2 subtype with t(8; 21)Objectives①Monitor C-KIT gene mutation in newly diagnosed and relapsed AML-M2 with t(8;21) patients, to evaluate the clinical characteristics and prognosis of mutated C-KIT(mutKIT)in AML-M2 patients with t(8;21).②Monitor the alteration of the AE9a ratio in newly diagnosed AML-M2 with t(8;21) patients, to study its correlation with mutKIT and analyze their prognostic impact.Methods①cDNAs from 55 newly diagnosed and 15 relapsed AML-M2 patients with t(8;21)were screened for mutKIT in exon 8 and 17 by PCR and sequencing.②Follow up the clinical and lab datas of these cases, then summarize the characteristics of mutKIT patients.③Monitor the alteration of the AE9a ratio in this 55 newly diagnosed AML-M2 patients with t(8;21) by using quantitative real-time PCR, we combine all the information with clinical features to study its correlation with mutKIT and analyze their prognostic impact.Results①Among 55 AML-M2 patients with t(8;21), 13(23.6%) had mutKIT and all mutated KIT in 17 exon. Point mutation occurred frequently in C-KIT mutations, these mutations were mostiy clustered in a hot spot spanning residues that the C-KIT kinase function domain of D816 mutations (53.8%).Among 15 relapsed AML-M2 patients with t(8;21), 8(53.3%) had mutKIT and all mutated KIT in 17 exon. The mutation rate of relapsed AML-M2 patients with t(8;21) was higher than the newly diagnosed ones(P<0.05).②Additional karyotype ratio was higher for mutKIT patients compared with wide-type C-KIT(wtKIT) patients(P<0.05). The peripheral WBC counts, hemoglobin level, platelet counts, percentage of blast cell in bone marrow, level of CD117 expression, age of onset and LDH level of patients with mutKIT and wtKIT were similar. The 2-year RFS rate (30.9%) and OS rate (32.1%) were lower for patients with mutKIT than wtKIT patients (RFS rate 53.2% and OS rate 71.6%, P<0.05).③13 newly diagnosed patients with C-KIT mutation were in the AML1-ETO9a positive group and in patients with mutKIT had a higher ratio of AE9a in total than the wtKIT patients (P<0.05), which indicated that AML1-ETO9a and mutKIT had correlation with each other.Conclusion①There were various types of mutKIT17 in AML-M2 patients with t(8;21) and the most frequently detected mutation of mutKIT17 was D816. The mutation rate of relapsed AML-M2 patients with t(8;21) was higher than the newly diagnosed ones.②The patients with mutKIT were always accompanied with additional chromosomal abnormalities, and the CD117 expression level was unrelated with C-KIT gene mutation state. The patients accompanied by mutKIT easily relapsed, and their survival time were short, predicting poor prognosis.③MutKIT and AML1-ETO9a had correlation with each other, which indicated they have closely relation with the prognosis of AML-M2 patients with t(8;21). |
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