Clinical Significance of Common Gene Mutations in 53 Patients with Acute Myeloid Leukemia Harboring 11q23/MLL Rearrangements / 中国实验血液学杂志

OBJECTIVE@#To investigate the clinical significance of AML patients with 11q23/MLL rearrangement, and to evaluate the effect of those mutations on the AML patients.@*METHODS@#53 cases involving translocations of chromosome 11q23 were identified by chromosome banding analysis. MLL rearrangements were detected by fluorescence in situ hybridization and/or multiplex nested PCR. The samples were screened for mutations in the candidate genes FLT3-ITD, FLT3-TKD, TET2, N-RAS, ASXLI, EZH2, DNMT3, C-Kit, NPM1, WT1, CEBPA by using genomic DNA-PCR and deep-sequencing.@*RESULTS@#21/53 MLL-rearranged AML cases showed at least one additional chromosomal aberrations. The most common additional aberration was +8. Gene mutations were observed in 23 cases (43.4%) and most cases showed singal mutation. N-RAS mutation was more frequent (8 cases, 15.1%), followed by WT1 mutation in 4 cases (7.5%), FLT3-ITD mutation in 3 cases, ASXL1 mutation in 2 cases, DNMT3A mutation in 2 cases, EZH2 mutation in 1 case, c-Kit17 mutation in 1 case, FLT3-TKD mutation in 1 case, and FLT3-ITD and TKD mutation coexistent in 1 case. No mutation was detected in CEBPA, NPM1, C-KIT8, TET2. Median OS for gene mutated patients was 8.5 months and 13 months for no mutated patients. Median OS for patients who received hematopoietic stem cell transplantation (HSCT) was 22.5 months and 7.5 months for patients who olny received chemotherapy.@*CONCLUSION@#A relatively high mutation frequency is observed in AML patients with 11q23/MLL rearrangements and most cases shows single mutation. The RAS signaling pathway alterations are most common. Gene mutation does not affect the OS of these patients, who show poor prognosis. A significantly higher Hb at initial diagnosis in FLT3 mutated patients is significantly higher than that in FLT3 wild-type cases. Patients who underwent HSCT show a better prognosis than those only received chemotherapy.

ARMS-PCR combined with capillary electrophoresis can be a sensitive and quantitative method for detection of MYD88-L265P mutation in lymphoma / 中国实验血液学杂志

OBJECTIVE@#To investigate the feasibility of sensitive and quantitative detection of MYD88 gene L265P mutation in lymphoma patients by using ARMS-PCR combined with capillary electrophoresis.@*METHODS@#ARMS-PCR amplified MYD88 gene was analyzed by capillary electrophoresis in ABI 3730 sequencer; Exon 5 of the same gene was sequenced bi-directionally as reported.@*RESULTS@#The sensitivity of detection L265P mutations by the ARMS-PCR combined with capillary electrophoresis and direct sequencing was 0.2% and 5%, respectively, according to the detection of the gradient-diluted plasmid standards. The detection rate of 184 patients was 13.59% and 8.28%, respectively (p<0.001). Moreover, the former method can successfully detect the mutation ratio(R=0.979), and the repeatabilities (CV=2.86%, 1.94%, 5.49%) are acceptable.@*CONCLUSION@#ARMS-PCR combined with capillary electrophoresis can quantitatively detect the MYD88 gene L265P mutation, and the detection sensitivity is significantly higher than sanger sequencing. As a supplement to the latter, it can effectively lead to the earlier diagnose and monitoring of minimal residual disease.

Detection of ASXL1 Mutation and CALR Mutation Coexistance in Patients with Ph Negative Myeloproliferative Neoplasm and Its Clinical Gignificance / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To explore the coexistence of ASXL1 and CALR gene mutations in patients with essential thrombocytheima (ET) and with primary myelofibrosis(PMF), and to compare the differences of clinical characteristics between ET and PMF patients carrying ASXL1 and CALR mutations, and ET and PMF patients carrying solitary gene mutation, and ET and PMF patients without any mutations.</p><p><b>METHODS</b>The mutations of ASXL1 gene at exon 12, CALR gene at exon 9 and MPL gene at exon 10 in 263 essential ET patients and 29 PMF patients were detected by PCR amplification followed by direct sequencing of genomic DNA. The JAK2V617F mutations were used by allele specific PCR detection.</p><p><b>RESULTS</b>72.6%(212/292)of patients harbored at least one mutation. The incidences of ASXL1 and CALR mutations were 5.8% and 30.5%, respectively. The frequencies of JAK2V617F and MPL mutations were 39.0% and 2.4%, respectively. 5.1%(15/292) of patients had double mutations, including ASXL1 and CALR(n=11), ASXL1 and JAK2V617F(n=2), MPL and CALR(n=1) and ASXL1 and MPL(n=1). The frequency of concurrent ASXL1 and CALR mutations was found to be high. Significant difference was found on hemoglobin levels and platelet counts between CALR and ASXL1 mutations and single mutation (P<0.05),however, the difference on leukocyte counts and median age was not found. Compared with negative patients, the presence of ASXL1 and CALR mutations was found to be significantly correlative with lower hemoglobin level (P=0.045), lower leukocyte count (P=0.002) and with higher platelet counts(P=0.001), but the difference of median age was not found.</p><p><b>CONCLUSION</b>The frequency of concurrent ASXL1 and CALR mutations is higher in ET patients. The coexistence of ASXL1 and CALR gene mutations significantly associated with lower hemoglobin level and higher platelet count.</p>

Frequently ABL kinase domain G:C→A:T mutation and uracil DNA glycosylase abnormal expression in TKI-resistant acute lymphoblastic leukemia of Chinese population / 中国实验血液学杂志

Most Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph(+) ALL) patients often show rapid recurrence and development of ABL kinase domain (KD) mutation after tyrosine kinase inhibitor (TKI) treatment. To further investigate the mechanism of Ph(+) ALL fast relapse after TKI treatment, ABL KD mutation in 35 Chinese Ph(+) ALL with TKI resistance was detected by direct sequencing. The results showed that 77.1% (27/35) Ph(+) ALL patients with TKI resistance had ABL KD mutation and 55.6% (15/27) Ph(+) ALL patients with ABL KD mutation had T315I. Interestingly, 77.8% (21/27) Ph(+)ALL showed ABL mutation G: C→A:T, including T315I, E255K and E459K. Furthermore, all the Ph(+) ALL patients with two or more ABL KD mutations collaborated with complex chromosome abnormality and all the TKI-resistant Ph(+) ALL patients, whose karyotype progressed from simple t (9;22) into complex, developed ABL KD mutation. Moreover, the expression level of uracil-DNA glycosylase UNG2, which inhibits G:C→A:T transition in genomic DNA, decreased in Ph(+) ALL with TKI-resistance compared to that in newly diagnosis Ph(+) ALL. It is concluded that there is a high frequent ABL KD G:C→A:T mutation and a high genomic instability in Chinese TKI-resistant Ph(+) ALL. In addition, the decreased UNG2 expression in TKI-resistant Ph(+) ALL probably contributes to their high rate of ABL KD G:C→A:T mutation.

Biocompatibility of polyethylene imine (PEI)-coated magnetic Fe₃O₄ nanoparticles in SHI-1 cells / 中华血液学杂志

<p><b>OBJECTIVE</b>To explore the feasibility of magnetic resonance cell imaging technology by using polyethylene imine (PEI)-coated magnetic nanoparticles of Fe₄O₄ (PEI-Fe₄O₄-MNPs) to track cell biology behavior.</p><p><b>METHODS</b>Endocytic PEI-Fe₄O₄-MNPs in SHI-1 cells were observed by transmission electron microscopy (TEM) . Iron contents of nano-labeled cells were analyzed by inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and Prussian blue staining. The proliferation ability of labeled cells was detected by cell counting kit-8 (CCK-8) assay; the differentiation and colony-forming abilities were also observed. SHI-1 cells without endocytosing PEI-Fe₄O₄-MNPs were used as control.</p><p><b>RESULTS</b>Our data showed that PEI-Fe₄O₄-MNPs could label SHI-1 cells. The labeling efficiency depended on the nanoparticles' concentration and the duration of cells treating. Inhibition rates of SHI-1cells labeled by 60-100 μg Fe/ml PEI-Fe₄O₄-MNPs were much higher than of 5-50 μg Fe/ml ones following treating by 5-100 μg Fe/ml PEI-Fe₄O₄-MNPs for 48 hrs. The expressions of CD11b and CD14 were (78.4±18.5)% and (18.7±2.9)% in control vs (83.3±14.2)% and (20.4±2.1)% in cells fractions treated by 30 μg Fe/ml PEI-Fe₄O₄-MNPs. Clony-forming rates of SHI-1 cells labeled by 0, 20 , 50 μg Fe/ml PEI-Fe₄O₄-MNPs were (25.20±7.22)%, (25.93±13.15)%, (23.37±9.33)%, respectively. Differentiation and colony-forming potentials of labeled cells were similar with control in the certain range of PEI-Fe₄O₄-MNPs concentration.</p><p><b>CONCLUSION</b>SHI-1 cells were efficiently labeled by PEI-Fe₄O₄-MNPs with well biocompatibilities in proper range of concentration, the latter could be coupled with magnetic resonance imaging (MRI) to track cells in vivo.</p>

The different characteristics of ABL kinase domain mutation in the Chinese Han nationality imatinib resistant Philadelphia chromosome-positive acute lymphoblastic leukemia and chronic myeloid leukemia / 中华血液学杂志

<p><b>OBJECTIVE</b>To identify the distribution and differentiation of ABL kinase domain mutation in the Chinese Han nationality imatinib resistant chronic myeloid leukemia (CML) and Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph(+)ALL).</p><p><b>METHODS</b>Bone marrow or peripheral blood samples of 112 imatinib resistant CML patients and 21 Ph(+)ALL patients were obtained from the first affiliated hospital of Soochow university according to local law. Total RNA was extracted from the mononuclear cells using a TRIzol reagent. ABL kinase domain (KD) mutation was detected by direct sequencing.</p><p><b>RESULTS</b>Of the 112 imatinib resistant CML patients, 54.46%(61 cases) had ABL KD mutation. Twenty-three mutants were identified in 20 amino acid sites and 23.21% (26 cases) ABL KD mutations were in P-loop region. ABL KD mutations were also detected in 71.43% (15 cases) imatinib resistant Ph(+)ALL patients, with 10 mutations in 8 amino acid sites. The most frequent mutation was T315I (28.57%), followed by E255K/V (19.05%) and Y253F/H (14.29%). The frequency of T315I was much higher in imatinib resistant Ph(+) ALL than that in imatinib resistant CML (P = 0.001). Ph(+)ALL with additional chromosomal aberrations also had a higher rate of ABL KD mutation than that of CML (P = 0.010). Ph(+)ALL gained ABL KD mutation faster than CML (P < 0.010).</p><p><b>CONCLUSION</b>Chinese imatinib resistant CML and Ph(+)ALL patients had different characteristics in ABL KD mutation. The rate of ABL KD mutation in Ph(+)ALL with additional chromosomal aberrations was much higher than that of CML with additional chromosomal aberrations.</p>

C-kit, NPM1 and FLT3 gene mutation patterns and their prognostic significance in 656 Chinese patients with acute myeloid leukemia / 中华血液学杂志

<p><b>OBJECTIVE</b>To evaluate the prevalence and distribution of C-kit, NPM1 and FLT3 gene mutations in patients with acute myeloid leukemia (AML), and to analyze the relationship between the gene mutations and their prognosis.</p><p><b>METHODS</b>Mutations in exon 8 and 17 of C-kit gene, exon 12 of NPM1 gene, exon 20 of FLT3-TKD gene, and exon 14/15 of FLT3-ITD gene were detected by direct sequencing. Clinical data was collected and followed up if the patient had accepted treatment in our hospital.</p><p><b>RESULTS</b>Among the 656 AML patients, mutations in C-kit exon 8 were found in 6 patients (0.9%), C-kit exon 17 in 33 (5.0%), NPM1 in 169 (25.8%), FLT3-TKD in 46 (7.1%), and FLT3-ITD in 178 (27.1%). Six subtypes of mutations were detected in C-kit exon 8, 8 in C-kit exon 17, 11 in FLT3-TKD, 15 in NPM1, of which 5 were not reported before. C-kit exon 17 mutations were more frequently detected in patients with t(8;21) and exon 8 in patients with inv(16) cytogenetic abnormality. No other gene mutations except FLT3 were detected in M(3) patients. NPM1 and ITD mutations were often detected in individuals with normal cytogenetics or M(5) and M(1) of FAB classification, and accompanied with high white blood cell counts in peripheral blood, high blast counts in bone marrow and low CD34 expression. The older the patients were when diagnosed, the more gene mutations and the higher white blood cell count were detected. More mutations were found in individuals with normal karyotype than that with other karyotypes. It appeared that FLT3-ITD was significantly associated with shorter overall survival (OS) (P = 0.004), NPM1 was not significantly associated with OS, but NPM1(+)/ITD(-) patients had the longest OS.</p><p><b>CONCLUSIONS</b>Our results showed that the mutation types and amounts had particular distribution in MICM subtypes, and were associated with white blood cell counts in peripheral blood, blast counts in bone marrow and prognosis. Especially for patients with normal karyotype, the genetic mutations could be new molecule marker.</p>

Monitoring the expression ratio of AML1-ETO9a isoform in t(8;21) acute myeloid leukemia and its significance / 中华血液学杂志

<p><b>OBJECTIVE</b>To study the expression ratio of AML1-ETO9a (AE9a) isoform in t(8;21) acute myeloid leukemia (AML) and its clinical significance.</p><p><b>METHODS</b>Bone marrow samples from 44 newly diagnosed t(8;21) AML patients co-expressed AE9a and AE were screened by RT-PCR. The alteration of the AE9a expression ratio was monitored during follow-up by using quantitative real-time RT-PCR (qPCR).</p><p><b>RESULTS</b>The expression level of AE9a was markedly lower than that of AE in these patients. There was a positive correlation between the expression level of AE9a and AE in most of bone marrow samples. The transcript level of both AE9a and AE was decreased in the 44 patients after one course of standard chemotherapy, but the percentage of AE9a expression level was increased in comparison with that before treatment (P < 0.05). After one course of standard chemotherapy treatment, the percentage of AE9a in incomplete remission (ICR) patients was significantly higher than that in CR patients (P < 0.05). Relapsed patients had a higher AE9a ratio than the unrelapsed patients (P < 0.05). During the remission, the percentage of AE9a in 11/17 relapsed patients obviously elevated even while the expression of AE fusion gene at low level.</p><p><b>CONCLUSIONS</b>AE9a and AE co-expressed in most of AML patients with t(8;21) translocation. The expression level of AE9a was lower than that of AE, and there is a positive correlation between the expression level of these two isoforms. The sensitivity of AE9a gene to the standard chemotherapy is less than that of the AE fusion gene. Monitoring the AE9a to AE ratio during the CR can predict the early relapse of the disease compared to monitoring the AE alone.</p>

The impact of HLA high resolution typing mismatching of donor-recipient pairs on outcome of unrelated donor hematopoietic stem cell transplantation / 中华血液学杂志

<p><b>OBJECTIVE</b>To study the impact of various human leukocyte antigen (HLA) high resolution typing mismatching of donor-recipient pairs on prognosis of unrelated donor hematopoietic stem cell transplantation.</p><p><b>METHODS</b>835 donor-recipient pairs of CMDP data from 2005 to 2010 were analyzed retrospectively. HLA-A, B, C, DRB1 and DQB1 typing were performed using SBT, SSOP and SSP methods. The diseases involved in acute myeloid leukemia (AML) (n = 288), acute lymphoid leukemia (ALL) (n = 227), chronic myeloid leukemia (CML) (n = 187), myelodysplastic syndrome (MDS) (n = 52), non-hodgkin's lymphoma(NHL) (n = 25), aplastic anemia(AA) (n = 42) and thalassemia (n = 14). Of 835 donor-recipient pairs, 362 were completely matched, 159 had a mismatch for a single allele, 125 had a mismatch for a single antigen, 95 had mismatched for both single allele and single antigen, 29 were mismatched at double allele, 20 at double antigen, 45 at multiple allele and antigen. The follow-up assessment was completed before March 2011.</p><p><b>RESULTS</b>HLA-matched pairs had higher overall survival (OS) than HLA-mismatched pairs (79.83% vs 73.15%), but there was no statistically significant differences (P > 0.05). HLA mismatch for a single allele plus a single antigen was a significantly risk factor for OS, disease free survival (DFS) and transplant-related mortality (TRM). The OS from high to low in different diseases were thalassemia, AA, CML, MDS, AML, NHL, and ALL. OS of HLA locus mismatch were DRB1 (94.4%), DQB1 (83.3%), B (75%), A (74.4%) and C (71.4%), respectively. OS of single allele mismatch at HLA locus from high to low were DRB1, C, A, B and DQB1.HLA-A, B, C locus mismatch were statistically significantly associated with lower OS and grade II-IV acute GVHD compared with HLA-matched pairs (P < 0.05). The donor-recipient pairs with HLA-B*15:01/B*15:05, DRB1*12:01/DRB1*12:02, C*04:01/C*03:04, DQB1*03:02/DQB1*03:03 alleles mismatch were given priority. But the donor-recipient pairs with HLA-B*39:01/B*39:05, C*15:02/C*14:02, C*08:01/C*03:04, C*07:02/C*15:02 alleles mismatch were risk factors for influence of OS and aGVHD.</p><p><b>CONCLUSION</b>The high resolution typing for HLA-A, B, C, DRB1, DQB1 can be identified nonpermissive mismatch, which is beneficial for the selection of a suitable donor improves survival on unrelated donor HSCT.</p>

Significance of interplay between Rap1 and cadherin to the development of myelodysplastic syndrome / 中华血液学杂志

<p><b>OBJECTIVE</b>To explore the hematopoietic pathophysiology of myelodysplastic syndrome (MDS) at stem/progenitor cell level by analyzing the gene expression profiles associated with hematopoiesis.</p><p><b>METHODS</b>The differentially expressed genes which were involved in the hematopoiesis were screened by microarray using CD34(+) cells from MDS patients firstly. RQ-PCR was then applied to validate the screened genes using CD34(+) cells from MDS-RA patients who had normal karyotype. The linkages with hematopoiesis among these validated genes were analyzed.</p><p><b>RESULTS</b>Among the differentially expressed genes in CD34(+) cells of MDS-RA patients, Rap1GAP was up-regulated significantly (P < 0.01). Cadherins, which can interplay with Rap1, including N-cadherin and E-cadherin, were down-regulated significantly (P < 0.01). β-catenin, a downstream effector of cadherins, was highly expressed in MDS-RA patients (P < 0.01). c-myc binding protein was down-regulated (P < 0.01), and c-myc promoter binding protein was up-regulated (P < 0.01). Rac1, Rac2 and Cdc42, which belong to RhoGTPases family and are associated with the cell morphology and hematopoiesis, were all expressed highly in MDS-RA patients (P < 0.01).</p><p><b>CONCLUSION</b>The abnormal expression of cadherin, β-catenin and c-myc associated genes were closely related to the dysplastic hematopoiesis of MDS. The down regulation of cadherin was associated with the positive feedback mechanism between Rap1 and cadherin. The aberrant expression of Rac1, Rac2 and Cdc42 may contribute to the morphological dysplasia of MDS.</p>

Disruption of blood brain-barrier by leukemic cells in central nervous system leukemia / 中华血液学杂志

<p><b>OBJECTIVE</b>To observe the effect of leukemic cells on blood-brain barrier (BBB) in mice with central nervous system leukemia (CNSL) by establishing mice CNSL model and an in vitro BBB model and explore the mechanism of leukemic cell infiltrating central nervous system (CNS).</p><p><b>METHODS</b>After splenectomy, cytoxan intraperitoneal injection, and sublethal irradiation, 10 BALB/c nu/nu mice were transplanted intravenously with 1.2 × 10(7) of SHI-1 human monocytic leukemic cells. Mice were monitored for survival and clinical manifestation of nerve palsy. The leukemic cells engrafted were examined by RT-PCR, histopathology and bone marrow (BM) smears. Immunofluorescence analysis with laser scanning fluorescence confocal microscopy was used to determine the expression of fibrinogen and tight-junction protein ZO-1. An in vitro BBB model composed of human brain microvascular endothelial cells (BMVECs) was developed on a Matrigel-based insert. Different leukemic cell lines were seeded onto the upper compartment of transwell insert. After incubated for 24 h with BMVECs, cells that had migrated into the lower compartment were counted and analyzed.</p><p><b>RESULTS</b>(1) Paralysis with or without sight loss was developed in half the mice 30-35 d after innoculated with SHI-1 cells. Leukemic cells infiltrates were observed in BM and in different part of brain tissues including brain parenchyma. The transcriptions of human MLL/AF6 fusion gene were also detected in BM and brain tissues in paralysis mice. The fibrinogen expression and ZO-1 disruption were detected in the infiltrated tissue. (2) After 24 h incubation with leukemic cells, the BMVECs sheets were disrupted and grew singly and ZO-1 expression was down-regulated markedly. SHI-1 cells showed more injurious to BMVECs and higher invasive rate \[(40.33 ± 1.53)% vs (11.83 ± 1.44)%, P < 0.05\] than HL-60 cells did.</p><p><b>CONCLUSION</b>One of the mechanisms of leukemic cells infiltrates CNS in CNSL is injure to the BBB.</p>

Construction of AML1-ETO eukaryotic expression vector and its effects on proliferation and differentiation of U937 cells / 中华血液学杂志

<p><b>OBJECTIVE</b>To construct a pcDNA3.1-AML1-ETO expression vector and investigate its effects on proliferation and differentiation of U937 leukemic cells.</p><p><b>METHODS</b>AML1-ETO gene was amplified by PCR from pCMV5-AML1-ETO and inserted into eukaryotic expression plasmid pcDNA3.1/V5-His-TOPO. The recombinant plasmid was transfected into U937 cells by Lipofectamin 2000. Individual clones selected with G418 were isolated. The integration and the expression levels of AML1-ETO in transfectants were determined by PCR, RT-PCR and Western blot analysis respectively. Trypan blue refusal staining method was used to detect the proliferation of U937 cells. Light microscope was applied to observe the morphologic changes of the cell. The expression of myeloid cell differentiation antigen was detected using flow cytometry.</p><p><b>RESULTS</b>The recombinant pcDNA3.1-AML1-ETO was confirmed by enzyme digestion and sequencing. The highly expressing AML1-ETO subclone was established. AML1-ETO was expressed in U937 cells transfected with pcDNA3.1-AML1-ETO. The growth of the monoclonal cells was inhibited evidently (P < 0.05). The expression of CD11b in transfected group \[(4.17 ± 0.31)%\] was lower than that in empty plasmid transfected group and non-transfected group \[(11.40 ± 0.17)% and (11.03 ± 0.15)%\] respectively (P < 0.001). Transfected cells displayed morphology of less differentiation. The expression level of CDl1b was unchanged in transfected cells treated with TPA (P > 0.05).</p><p><b>CONCLUSION</b>The eukaryotic expression vector for AML1-ETO gene was successfully constructed and expressed in U937. AML1-ETO inhibits the proliferation and differentiation of transfected cells. It provides the basis for further study of mechanisms of AML1-ETO in leukemogenesis.</p>

Apoptosis of chronic myeloid leukemia stem/progenitor cells induced by anti-CD44 monoclonal antibody IM7 in vitro / 中国实验血液学杂志

The aim of this study was to investigate the apoptosis-inducing effect of anti-CD44 monoclonal antibody IM7 on chronic myeloid leukemia (CML) stem/progenitor cells in vitro and to explore its possible mechanism. Leukemic stem/progenitor cells (LSPCs) expressing CD34(+), CD38(-) and CD123(+) were isolated from bone marrow (BM) cells of 20 patients with newly-diagnosed chronic myeloid leukemia by using EasySep(TM) magnetic beads. The percentage of apoptotic CML-LSPCs was assayed by Annexin-V/PI staining; the expression changes of c-myc and NF-kappaB mRNA were detected by real-time quantitative PCR (RQ-PCR) and RT-PCR; the NF-kappaB activity was detected by NF-kappaB Activation Nuclear Translocation Assay Kit; the BCL-2 protein expression was determined in the Western blot method. The results showed that the IM7 effectively induced apoptosis of CML-LSPCs; the mean percentage of early apoptotic cells significantly increased, as compared with the untreated control CML-LSPCs cells 12.58 +/- 2.84% vs 5.42 +/- 1.84% (p < 0.05). The c-myc, NF-kappaB mRNA expressions were down-regulated as compared with the control group (0.65 +/- 0.10 vs 1.00, 0.42 +/- 0.21 vs 1.00, respectively) (p < 0.01) by RQ-PCR and (0.49 +/- 0.09 vs 0.60 +/- 0.12, 0.47 +/- 0.11 vs 0.67 +/- 0.08, respectively)(p < 0.01) by RT-PCR. The BCL-2 protein level in CML-LSPCs treated with IM7 also decreased as compared with the control group (p < 0.01). In addition, the depression of NF-kappaB activity was observed through fluorescence microscope. It is concluded that the anti-CD44 monoclonal antibody IM7 effectively induces apoptosis of CML-LSPCs through down-regulating c-myc and bcl-2 mRNA expression, and decreasing NF-kappaB activity in CML-LSPCs.

A quantitative assay for JAK2 mutation in 135 patients with chronic myeloproliferative neoplasms / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate the frequency and mutational status of JAK2 mutation in Chinese patients with chronic myeloproliferative neoplasms (MPN) and study the relative quantitation and clinical implications of mutated JAK2 transcript.</p><p><b>METHODS</b>JAK2 mutation and the mutational status were screened with amplification-refractory mutation sequencing polymerase chain reaction (ARMS-PCR), the relative quantity of mutated JAK2 mRNA by using capillary electrophoresis.</p><p><b>RESULTS</b>JAK2V617F mutation was detected in 95 of 135 MPN patients, including 37 (97.4%) of 38 polycythemia vera (PV), 56 (59.6%) of 94 essential thrombocythemia (ET) and 2 of 3 idiopathic myelofibrosis (IMF) patients; the difference between the mutations in PV and ET was significant (P<0.05). Of 95 JAK2V617F patients examined, 18/38 PV patients (47.3%) and 17/94 (18.1%) ET patients and 1 IMF patient were homozygotes, and ET patients showed lower prevalence of homozygote (P<0.05). In 95 MPN patients, the mutated mRNA ratio was higher in homozygote than in heterozygote patients. PV heterozygote patients showed higher levels of mutated JAK2 mRNA than ET heterozygote patients (P<0.05). The levels of JAK2V617F mRNA in patients over 60 years of age were significantly higher than that in those less than 60 years of age (P<0.001). Higher leukocyte counts were observed in PV and ET patients with higher levels of mutated JAK2 mRNA (P<0.05). The presence of JAK2V617F was found to be significantly associated with higher hemoglobin level in ET patients. Cytogenetic analysis was performed in 101 of the 135 patients, the association between abnormal karyotype and JAK2V617F was not found.</p><p><b>CONCLUSION</b>The ARMS-PCR technique can be used to detect the frequency and mutational status of JAK2V617F mutation, and along with capillary electrophoresis, the estimation of minimal residual disease becomes possible.</p>

Quantitative analysis for JAK2 mutation in 98 patients with essential thrombocythemia and its clinical significance / 中国实验血液学杂志

The objective of this study was to identify the frequency and types of JAK2V617F mutation in chinese patients with essential thrombocythemia (ET), to quantitatively detect the level of mutation transcripts and to investigate its clinical significance. The frequency and types of JAK2V617F mutation were detected by amplification-refractory mutation sequencing polymerase chain reaction (ARMS-PCR), the transcript level of JAK2V617F mutation was determined by using capillary electrophoresis. The results indicated that the JAK2V617F mutation was detected in 59 out of 98 patient with ET, 18 of whom were homozygous mutation. The mean age of patients with homozygous and heterozygous mutation was higher than that of patients with wild type mutation (p < 0.05). The quantitative assay using capillary electrophoresis showed that the transcript level of JAK2V617F mutation in patients with homozygous mutation was (89.9 +/- 6.7)%, which was higher than that in patients with heterozygous mutation (57.1 +/- 6.7)% (p < 0.05); the transcript level of JAK2V617F mutation in patients with age < 60 years was (62.3 +/- 16.5)%, which was lower than that in patients with age > 60 years (72.4% +/- 15.8)% (p < 0.05). The rate of thrombotic complications in patients with JAK2V617F-positive was higher than that in patients with JAK2V617F-negative in which the rate of thrombotic complication in patients with homozygous mutation was higher than that in patients with heterozygous mutation (p < 0.05). Compared with patients without thrombotic events, there were higher level of transcripts of JAK2V617F mutation in patients with thrombotic events. It is concluded that the JAK2V617F positive and negative patients with ET display the different clinical features, therefore, the analysis of mutation types and detection of transcript levels not only helps to identify the disease status and progression, but also guides the treatment of ET patients.

Detection of clonal immunoglobulin and T-cell receptor gene rearrangements in newly diagnosed adult patients with acute lymphoblastic leukemia by using multiplex PCR protocols / 中华血液学杂志

<p><b>OBJECTIVE</b>To provide the evidence of RQ-PCR-based assessment of minimal residual disease (MRD), the clonal immunoglobulin and T-cell receptor (Ig/TCR) gene rearrangements were identified in newly diagnosed adult patients with acute lymphoblastic leukemia (ALL) by multiplex PCR protocols.</p><p><b>METHODS</b>Forty newly diagnosed adult patients with B-lineage (B-) and T cell (T-) ALL were involved in this study. All DNA samples were obtained from the bone marrow (BM) mononuclear cells (MNC). IgH, IgK, TCRB, TCRG and TCRD gene rearrangements were detected by BIOMED-2 multiplex PCR protocols, which included 96 different primers and 14 multiplex PCR tubes.</p><p><b>RESULTS</b>The clonal immunoglobulin (Ig) rearrangements were found in 96% of B-ALL, 86% being IgH and 14% IgK. While in T-ALL, clonal TCR rearrangements were found in all of the patients, 83% being TCRB, 78% TCRG and 39% TCRD. More than two clonal markers were found in 91% of B-ALL and 89% of T-ALL patients.</p><p><b>CONCLUSIONS</b>The detection rate of clonal rearrangements using the BIOMED-2 14 multiplex PCR tubes is high, which can detect virtually all clonal B and T-cell proliferations. It can be used for diagnostic clonality studies as well as for the identification of PCR targets suitable for the detection of minimal residual disease.</p>