Integrative genomic and transcriptomic profiling reveals distinct molecular subsets in adult mixed phenotype acute leukemia

Mixed phenotype acute leukemia (MPAL) is a subtype of leukemia in which lymphoid and myeloid markers are co-expressed. Knowledge regarding the genetic features of MPAL is lacking due to its rarity and heterogeneity. Here, we applied an integrated genomic and transcriptomic approach to explore the molecular characteristics of 176 adult patients with MPAL, including 86 patients with T-lymphoid/myeloid MPAL (T/My MPAL-NOS), 42 with Ph+ MPAL, 36 with B-lymphoid/myeloid MPAL (B/My MPAL-NOS), 4 with t(v;11q23), and 8 with MPAL, NOS, rare types. Genetically, T/My MPAL-NOS was similar to B/T MPAL-NOS but differed from Ph+ MPAL and B/My MPAL-NOS. T/My MPAL-NOS exhibited higher CEBPA, DNMT3A, and NOTCH1 mutations. Ph+ MPAL demonstrated higher RUNX1 mutations. B/T MPAL-NOS showed higher NOTCH1 mutations. By integrating next-generation sequencing and RNA sequencing data of 89 MPAL patients, we defined eight molecular subgroups (G1-G8) with distinct mutational and gene expression characteristics. G1 was associated with CEBPA mutations, G2 and G3 with NOTCH1 mutations, G4 with BCL11B rearrangement and FLT3 mutations, G5 and G8 with BCR::ABL1 fusion, G6 with KMT2A rearrangement/KMT2A rearrangement-like features, and G7 with ZNF384 rearrangement/ZNF384 rearrangement-like characteristics. Subsequently, we analyzed single-cell RNA sequencing data from five patients. Groups G1, G2, G3, and G4 exhibited overexpression of hematopoietic stem cell disease-like and common myeloid progenitor disease-like signatures, G5 and G6 had high expression of granulocyte-monocyte progenitor disease-like and monocyte disease-like signatures, and G7 and G8 had common lymphoid progenitor disease-like signatures. Collectively, our findings indicate that integrative genomic and transcriptomic profiling may facilitate more precise diagnosis and develop better treatment options for MPAL.

[Clinical Characteristics and Prognosis of Acute Myeloid Leukemia Patients with inv(16)/t(16;16)(p13.1;q22) and/or CBFβ-MYH11]

OBJECTIVE

To summarize the clinical and laboratory characteristics of patients with acute myeloid leukemia (AML) with inv(16)/t(16;16) (p13.1;q22), and to analyze the risk factors affecting the prognosis of the patients.

METHODS

AML patients with inv(16)/t(16;16) (p13.1;q22) and/or CBFβ-MYH11⁺ admitted to the Department of Hematology, The First Affiliated Hospital of Soochow University from January 1, 2008 to October 30, 2019 were retrospective analyzed, the clinical and laboratory indicators, as well as treatment plans and efficacy evaluations of the patients were all recorded. Furthermore, related factors affecting the overall survival (OS) and event-free survival (EFS) of the patients were analyzed.

RESULTS

Among 151 AML patients with inv(16)/t(16;16) (p13.1;q22) and/or CBFβ-MYH11⁺, the percentage of additional chromosomal abnormalities was about 27.8%, and the most common additional chromosomal abnormality was +22 (33/151, 21.8%), followed by +8 (11/151, 7.3%). There were 112 patients with perfect NGS examination, and the result showed the most common accompanying gene mutations were KIT mutation (34/112, 30.4%) and FLT3 mutation (23/112, 20.5%). Univariate analysis showed that factors affecting EFS included: NE≤0.5×10⁹/L (P=0.006) and combined K-RAS mutation (P=0.002); Factors affecting OS included: Age≥50 years old (P<0.001) and NE≤0.5×10⁹/L (P=0.016). Multivariate analysis showed that NE≤0.5×10⁹/L (P=0.019) was the risk factors affecting OS. The proportion of bone marrow eosinophilia (BME)≥10.00% (P=0.029) was the risk factors affecting EFS.

CONCLUSION

The prognosis for those newly diagnosed AML patients who were of advanced age, the high proportion of bone marrow eosinophils, K-RAS mutations, and agranulocytosis is poor. The treatment plans can be adjusted in the early stage to improve the prognosis of such patients.

[An interlaboratory comparison study on the detection of RUNX1-RUNX1T1 fusion transcript levels and WT1 transcript levels]

Objective: To investigate the current status and real performance of the detection of RUNX1-RUNX1T1 fusion transcript levels and WT1 transcript levels in China through interlaboratory comparison. Methods: Peking University People's Hospital (PKUPH) prepared the samples for comparison. That is, the fresh RUNX1-RUNX1T1 positive (+) bone morrow nucleated cells were serially diluted with RUNX1-RUNX1T1 negative (-) nucleated cells from different patients. Totally 23 sets with 14 different samples per set were prepared. TRIzol reagent was added in each tube and thoroughly mixed with cells for homogenization. Each laboratory simultaneously tested RUNX1-RUNX1T1 and WT1 transcript levels of one set of samples by real-time quantitative PCR method. All transcript levels were reported as the percentage of RUNX1-RUNX1T1 or WT1 transcript copies/ABL copies. Spearman correlation coefficient between the reported transcript levels of each participated laboratory and those of PKUPH was calculated. Results: ①RUNX1-RUNX1T1 comparison: 9 samples were (+) and 5 were (-) , the false negative and positive rates of the 20 participated laboratories were 0 (0/180) and 5% (5/100) , respectively. The reported transcript levels of all 9 positive samples were different among laboratories. The median reported transcript levels of 9 positive samples were from 0.060% to 176.7%, which covered 3.5-log. The ratios of each sample's highest to the lowest reported transcript levels were from 5.5 to 12.3 (one result which obviously deviated from other laboratories' results was not included) , 85% (17/20) of the laboratories had correlation coefficient ≥0.98. ②WT1 comparison: The median reported transcript levels of all 14 samples were from 0.17% to 67.6%, which covered 2.6-log. The ratios of each sample's highest to the lowest reported transcript levels were from 5.3-13.7, 62% (13/21) of the laboratories had correlation coefficient ≥0.98. ③ The relative relationship of the reported RUNX1-RUNX1T1 transcript levels between the participants and PKUPH was not always consistent with that of WT1 transcript levels. Both RUNX1-RUNX1T1 and WT1 transcript levels from 2 and 7 laboratories were individually lower than and higher than those of PKUPH, whereas for the rest 11 laboratories, one transcript level was higher than and the other was lower than that of PKUPH. Conclusion: The reported RUNX1-RUNX1T1 and WT1 transcript levels were different among laboratories for the same sample. Most of the participated laboratories reported highly consistent result with that of PKUPH. The relationship between laboratories of the different transcript levels may not be the same.

[Effect of Additional Chromosomal Abnormalities on the Outcome of CML-CP Patients Receiving TKI Therapy]

OBJECTIVES

To explore the effect of additional chromosomal abnormalities on the prognosis and outcome of CML-CP patients receiving imatinib therapy.

METHODS

The clinical and genetic data of 589 CML-CP patients receiving imatinib treatment between May 2009 and October 2014 in the 1st Affiliated Hospital of Soochow University were analyzed, the 589 patients were divided into 5 groups according to the karyotypes at the initial diagnosis. The OS(overall survival), PFS (progression-free survival), EFS (event-free survival), Cumulative MMR (major molecular remission) and Cumulative CCyR (complete cytogenetic remission) were calculated by using the Kaplan-Meier method and compared by using the log-rank text by Graphpad 6.0. The χ² test was used to compare the frequency of optimal molecular response at 3, 6, 12 months among the 5 groups.

RESULTS

There was significant difference about the frequency of optimal molecular response at 3 and 6 months between CML-CP patients with additional chromosomal abnormalities and those with classic t(9;22) ［50%（12/24） vs. 73.94%(261 /353), P<0.05; 50%(10 /20) vs. 72.05%(232 /322) (P<0.05)］, and the same significant difference was found at 6 months between the group with variant translocations and that with classic t(9;22) ［53.3% (16 /30) vs. 72.05%(232 /322) (P<0.05)］. The P values of cumulative CCyR (P<0.05) and EFS (P<0.01) for 4 years were statistically significant between CML-CP patients with additional chromosomal abnormalities and the other 4 groups. Compared one to another, there was the significant difference in cumulative CCyR and EFS for 4 years between CML-CP patients with additional chromosomal.abnormalities and those with classic t(9;22) (47.25% vs. 84.01%)(P<0.05); (75.03% vs. 90.01%)(P<0.01).

CONCLUSION

The additional chromosomal abnormalities influence the outcome of CML-CP patients receiving imatinib treatment, which make poor prognosis.

[Allogeneic hematopoietic stem cell transplantation for the treatment of acute myeloid leukemia with primary thrombocytosis: three cases report and literatures review]

目的

探讨原发性血小板增多症（ET）转化急性髓系白血病（AML）的病情变化特点及异基因造血干细胞移植（allo-HSCT）的治疗价值。

方法

回顾性分析3例ET转AML患者的临床特征、实验室检查结果及诊治经过，复习相关文献。

结果

例1，男，44岁，初诊ET时PLT 500×10⁹/L，3年后疾病转变为骨髓增生异常综合征时WT1基因由初诊时77拷贝/10 000 ABL拷贝升至13 171拷贝/10 000 ABL拷贝，染色体核型发生异常改变，在地西他滨治疗过程中快速进展为AML。例2，男，58岁，诊断ET时PLT 2 100×10⁹/L，9年后疾病进展为AML，WT1基因由初诊时130拷贝/10 000 ABL拷贝升至3 222拷贝/10 000 ABL拷贝，在化疗期间短期内复发。例3，男，60岁，初诊ET时PLT 900×10⁹/L，5年后疾病转化为AML，WT1基因由初诊时56拷贝/10 000 ABL拷贝升至3 696拷贝/10 000 ABL拷贝，化疗期间出现中枢神经系统侵犯。例1移植前未缓解，例2缓解后短期内复发，例3出现髓外侵犯。3例患者均顺利完成allo-HSCT，移植后骨髓缓解，染色体核型正常，例3中枢神经系统病灶消失，JAK2基因突变均转阴，WT1基因表达均<200拷贝/10 000 ABL拷贝，未发生严重并发症。

结论

ET转化的AML病情凶险，allo-HSCT是目前唯一可能治愈此疾病的方法。

[Immune reconstruct regularity profile of KIR2DL1 and KIR3DL1 in unrelated-donor allogeneic hematopoietic stem cell transplantation]

Objective: To investigate the immune reconstruct regularity profile of KIR2DL1 and KIR3DL1 in unrelated-donor allogeneic hematopoietic stem cell transplantation (allo-HSCT) with KIR-AA genotype. Method: 75 donor-recipient pairs were performed by KIR genotying using PCR-SSP, and all donors were identified with KIR-AA genotype. Dynamic detections (including unrelated-donor on the day of transplantation and the recipient each month post allo-HSCT) of the expression of KIR2DL1/3DL1 on NK cell and mRNA level were performed in 291 cases using flow cytometry (FCM) and real-time fluorescent quantitation PCR (RT-qPCR) . Result: ①The median expression of KIR2DL1 in unrelated-donor on transplant's day was 21.60%, the median expression of KIR2DL1 in recipient 1M, 2M, 3M and 3-6M after transplantation were 7.40%, 12.00%, 16.92%, 17.64% respectively. The median expression of KIR2DL1 in unrelated-donor on transplant's day was 265.14 copies/10 000abl copies, the median expression of KIR2DL1 in recipient 1M, 2M, 3M, 3-6M, 6-9M, 9-12M after transplantation were 332.17, 438.31, 723.25, 414.17, 180.76 and 234.67 copies/10 000abl copies respectively. The median expression of KIR2DL1 on NK cells and mRNA level gradually increased at all time points after transplantation, and reached the highest expression at 3 months after transplantation. But mRNA expression levels increased earlier than NK cell membrane proteins. ②The median expression of KIR3DL1 in unrelated-donors on transplant's day was 18.56%, the median expression of KIR3DL1 in recipient 1M, 2M, 3M, 3-6M after transplantation were 23.83%, 22.57%, 23.02%, 21.60% respectively. The median expression of KIR3DL1 in unrelated-donor on transplant's day was 572.29 copies/10 000abl copies, the median expression of KIR3DL1 in recipient 1M, 2M, 3M, 3-6M, 6-9M, 9-12M after transplantation were 1 233.74, 1 140.42, 876.73, 1 057.07, 739.02 and 514.43 copies/10 000abl copies respectively. The median expression of KIR3DL1 on NK cells and mRNA level were higher than donors at 1 month after transplantation, and stable expression at all time points after transplantation, so mRNA and NK cell membrane proteins expression increased at the same time. Conclusion: The immune reconstruct regularity of KIR2DL1 and KIR3DL1 gene were different, which provided an experimental basis for selecting the best time to detect the expressions of KIR2DL1 and 3DL1 after transplantation.

[CCL2 Protein Regulates Migration and Invasion of THP-1 cells by Autosecreting Inflammatory Chemokines]

OBJECTIVE

To investigate the effects and mechanism of CCL2 on the migration and invasion of human leukemia cell THP-1.

METHODS

The CCL2 gene was recombined with the transfer plasmid-PLVX and transfected into THP-1 cells. The CCL2 expression at RNA level was detected by RT-PCR, the CCL2 expression at protein level was determined by Western blot and ELISA, the influence of overexpression of CCL2 recombinant protein and THP-1 cells on the migration and invasion ability of THP-1 cells was analyzed by transwell migration and invasion tests, the PCR-array of migration-related cytokines was used to clarify the patential mechanism.

RESULTS

With the Trans-Matrigel assay, the concentration of CCL2 in THP-1 transfected with CCL2 in the upper cells was higher than that in the lower cells, meanwhile, the invasion ability of CCL2-transfected THP-1 cells decreased. Increasing recombinant protein of CCL2 (rpCCL2) in the lower cells promoted migration of THP-1 cells. Migration RT2 profiler PCR array showed that the cells treated with rpCCL2 had higher levels of expression of CCL2, EPX, SPP1, CX3CL1 and CXCL13, as compared with control group.

CONCLUSION

CCL2 affects the migration and invasion of THP-1 by autosecreting a series of inflammatory chemokines.

[All-Trans Retinoic Acid and Decitabine Synergistically Induce Anti-Leukemia Effect on U937 Cell Line and Newly Diagnosed Elder AML Patients]

OBJECTIVE

To investigate the effect of all transretinoicacid(ATRA) combined with decitabine (5-Aza-2'-deoxycytidine;DAC) on DNA methylation and gene expression of p16INK4a (p16) and retinoic acid receptor β (RARβ), and to explore their combined anti neoplastic effect on U937 cells and newly diagnose delder acute myeloid leukemia(AML) patients.

METHODS

The expression levels of p16 and RARβ were determined by qRT-PCR and Western blot. Methylation-specific PCR was used to analyze their methylation status. WST-1 and flow cytometry were performed to detect growth inhibition, differentiation, apoptosis and cell cycle of U937 cells respectively.

RESULTS

The expression p16 and RARβ was down-regulated by promoter hypermethylation in newly diagnose delder AML patients and U937 cells. Combination treatment of ATRA and DAC induced DNA hypomethylation as well as gene expression of p16 and RARβ, which contributed to the growth inhibition, differentiation, apoptosis and cell cycle arrest of U937 cells. In addition for elder AML patients intolerable to standard chemotherapy, the combination regimen of ATRA and DAC showed antineoplastic activity accompamied by up-regulation of p16 and RARβ expression and decrease of bone marrow blast, moreover the parients showed good tolerence to the reginen.

CONCLUSION

The regimen of ATRA combined with DAC as the combination therapeutic strategy for inducing differentiation and demethylation possesses the anti-AML potency, and contributes to optimizing the therapeutic strategy for elder AML patients and promoting the clinical prognosis.

[Over-expression of C3AR1 Promotes HL-60 Cell Migration and Invasion]

OBJECTIVE

To investigate the effect of C3AR1 on migration and invasion of HL-60 cells and its mechanism.

METHODS

The HL-60 cells overexpresing C3AR1 was constructed, and the HL-60-C3AR1 cell line was validated by real-time PCR and Western blot. The migration and invasion assay were performed by using transwell system, the PCR Array and flow cytometry were employed to reveal the potential mechanisms.

RESULTS

C3AR1 gene was significantly expressed in AL cell lines, especially in acute myeloid leukemia(AML cell lines). C3a and SDF-1 together promoted migration and invasion of C3AR1 over-expressed HL-60 cells. The PCR array detection found that 16 genes (including CCL2) were significantly upregulated and 4 genes were significantly down-regulated. However, the expression of CXCR4 did not significantly change after treated by C3a and SDF-1 together.

CONCLUSION

Over-expression of C3AR1 shows the effects on the migration and invasion of HL-60 cells under the treatment of C3a and SDF-1 together, which may be mediated by the regulation of CCL2 and other genes related to chemotactic factors.

Coexistence of p210BCR-ABL and CBFβ-MYH11 fusion genes in myeloid leukemia: A report of 4 cases

Numerous acquired molecular and cytogenetic abnormalities are strongly associated with hematological malignancies. The breakpoint cluster region-ABL proto-oncogene 1 (BCR-ABL) rearrangement leads to a p210 chimeric protein in typical chronic myeloid leukemia (CML), whereas 17-25% of patients with acute lymphocytic leukemia and 0.9-3% patients with de novo acute myeloid leukemia (AML) carry a p190BCR-ABL fusion protein. Cases of patients with AML/CML carrying two specific primary molecular changes, BCR-ABL and core binding factor-β-myosin heavy chain 11 (CBFβ-MYH11) fusion genes have been rarely reported. The present study aimed to understand the nature and mechanism of this particular type of leukemia through case reports and literature review. A total of four patients who were diagnosed as AML/CML with BCR-ABL and CBFβ-MYH11 fusion genes in the First Affiliated Hospital of Soochow University (Suzhou, China) between January 2004 and December 2012 were examined. Morphological analysis of bone marrow cells, flow cytometry, quantitative polymerase chain reaction of p210BCR-ABL and CBFβ-MYH11 transcripts as well as cytogenetic and fluorescence in situ hybridization analyses were performed. A total of 4 patients who exhibited fusion of p210BCR-ABL and CBFβ-MYH11 were identified. A single patient (case 1) was first diagnosed CML-acute phase (AP), which progressed rapidly to CML-blast crisis (BC), and three patients (cases 2, 3 and 4) were diagnosed with AML with bone marrow eosinophilia at first presentation with no evidence of previous onset of CML. All cases achieved remission following conventional chemotherapy/hematological stem cell transplantation combined with the inhibitor of tyrosine kinase (TKI) maintenance therapy. The patients with CML carrying and expressing BCR-ABL and CBFβ-MYH11 fusion genes appeared more likely to rapidly progress to AP or BC. Therefore, the product of the CBFβ-MYH11 fusion gene may serve an important role in the transformation of CML. The co-expression of p210BCR-ABL and CBFβ-MYH11 fusion genes in myeloid leukemia may be a molecular event occurring not only during the development of CML, but also in AML.

[Prognostic Significance of the Percentage of Blasts with CD34+/CD38low/-/CD123+ Phenotype in Acute Myeloid Leukemias]

OBJECTIVE

To investigate the percentage of blasts with the CD34⁺/CD38^low/-/CD123⁺ phenotype in de novo acute myeloid leukemia (AML) patients and analyse its correlation with prognosis.

METHODS

The percentage of CD34⁺/CD38^low/-/CD123⁺ cells in the blast population of 148 newly diagnosed patients with AML was determined by using flow cytometry and its correlation with complete response, disease-free survival and overall survival were evaluated.

RESULTS

The median percentage of CD34⁺/CD38^low/-/CD123⁺ cells in newly diagnosed patients was 2.8% (ranged from 0.01 to 67%). The high expression of CD34⁺/CD38^low/-/CD123⁺ in AML patients positively correlated with the NPM1 wild-type (χ²=5.194,P<0.05), but did not relate with the positive FLT3-ITD mutations (χ²=0.418,P>0.05). Further multivariable analysis showed that the higher expression of the CD34⁺/CD38^low/-/CD123⁺ was associated with lower complete remission (P<0.05), worse disease-free survival(P<0.01) and shorter overall survival(P<0.01) in AML patients.

CONCLUSION

The percentage of CD34⁺/CD38^low/-/CD123⁺ cells at diagnosis significantly correlates with the response to treatment and survival. This prognostic marker may be used to rapidly identify the risk of treatment failure in clinical practice.

[Critical roles of matrix metalloproteinases secreted by leukemic cells in the pathogenesis of central nervous system leukemia]

目的

观察白血病细胞分泌的基质金属蛋白酶（MMP）-2和MMP-9对脑微血管内皮细胞（BMVEC）紧密连接蛋白ZO-1、claudin-5、occludin表达及对血脑屏障（BBB）通透性的影响，探讨MMP-2和MMP-9在中枢神经系统白血病（CNSL）发病机制中的作用。

方法

①实时定量PCR检测SHI-1、HL-60、U937细胞MMP-2、MMP-9基因的转录水平；明胶酶谱法检测细胞培养上清中MMP-2和MMP-9蛋白表达；体外穿膜实验观察各白血病细胞株的侵袭能力。②将原代人BMVEC接种于铺有Matrigel胶和纤维黏连蛋白包被的Transwell小室系统中，建立体外BBB模型。将蛋白酶抑制剂GM6001处理或未处理的SHI-1、HL-60、U937细胞或MMP-2/MMP-9基因沉默的SHI-1细胞接种于BBB模型的Transwell小室上层与BMVEC共培养，倒置相差显微镜观察BMVEC的形态变化，激光共聚焦显微镜观察紧密连接蛋白ZO-1、claudin-5和occludin的表达，计算白血病细胞的穿膜率。

结果

①SHI-1细胞表达较高转录水平的MMP-2和MMP-9及酶活性，且侵袭能力强于HL-60、U937细胞（P< 0.01）。②与HL-60、SHI-1和U937细胞共培养后，融合致密的BMVEC之间出现间隙、细胞呈单个生长，紧密连接蛋白ZO-1、claudin-5和occludin的表达明显下调，各白血病细胞均不同程度地穿过体外BBB进入Transwell小室下层。其中SHI-1细胞对BMVEC的形态改变及3种紧密连接蛋白的下调最为明显，穿膜率最高。GM6001明显抑制白血病细胞分泌MMP-2和MMP-9，使BMVEC的形态有所恢复，同时上调ZO-1、claudin-5和occludin的表达，降低了BBB的通透性。③用siRNA分别沉默MMP-2和MMP-9基因后，SHI-1细胞分泌MMP-2和MMP-9被抑制，SHI-1细胞穿膜率较沉默前分别下降43.64％和57.30%（P<0.01），ZO-1、claudin-5和occludin表达上调。

结论

白血病细胞株分泌的MMP-2和MMP-9能通过降解BMVEC紧密连接蛋白ZO-1、claudin-5和occludin而破坏BBB。

[EVI1 expression, clinical and cytogenetical characteristics in 447 patients with acute myeloid leukemia]

Objective: To investigate EVI1 expression and its associated clinical and cytogenetic characteristics in 447 acute myeloid leukemia (AML) patients. Methods: EVI1 expressions were measured in 447 AML cases from Jan. 2007 to Apr. 2015 to couple with clinical, cytogenetic and mutations' characteristics to summarize the features of AMLs with high EVI1 expression. Results: 17.9% of AML were high EVI1 expression (EVI1 +), and the remainder low EVI1 expression (EVI1-). No significant differences between the two groups in terms of age, sex, hemoglobin level, white blood cell count and platelet count were observed. More M0, M5 and M6 subtypes were observed in EVI1+ group (P= 0.027, 0.004 and 0.011, respectively). Cytogenetic abnormalities of 11q15, 11q23/MLL, 3q26, -7/7q- and t (9;11) were observed more frequently in EVI1 + group (P<0.001, <0.001, <0.001, <0.001, =0.014, respectively). Normal karyotype, inv (16), t (8;21) were observed more frequent in EVI1- group (P=0.001, 0.009, 0.002, respectively). EVI1 + was more observed in high risk cytogenetics. Mutation of NPM1 was more observed in EVI1- group (P <0.001). Remission rate in EVI1 + group was significantly lower than EVI1- group (P<0.001). Leukemia-free survival was improved in EVI1 + AML patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT). Conclusions: High EVI1 expression was more observed in FAB subgroup M5, harbored more cytogenetic abnormalities of 11p15, 11q23/MLL, 3q26 rearrangement, -7/7q- and t (9;11). Remission rate of high EVI1 expression AML was lower, which could be improved by allo-HSCT.

Arsenic trioxide and triptolide synergistically induce apoptosis in the SKM‑1 human myelodysplastic syndrome cell line

Although certain combination therapies comprising arsenic trioxide (As₂O₃) with other agents exist for the treatment of several types of human cancer, few As₂O₃ combination therapies are clinically effective for myelodysplastic syndromes (MDS). Triptolide (TL) may be an effective therapeutic agent for the treatment of MDS. However, to date, there is no combination therapy for MDS with As₂O₃ and TL. Therefore, the aim of the present study was to investigate this combination therapy on the apoptosis of MDS SKM-1 cells. The MDS SKM-1 cells were treated with As₂O₃, TL or the two in combination at various concentrations, or were mock-treated. Cell viability, cell apoptosis, levels of reactive oxygen species (ROS) and the expression of the cell apoptosis-associated genes, B cell lymphoma-2 (Bcl-2), Bcl-2-associated X protein (Bax) and caspase-3, were determined using an MTT assay, flow cytometric analysis of annexin V-fluorescein isothiocyanate/propidium iodide double-stained cells, flow cytometic analysis of intracellular 2′,7′-dichlorodihydrofluorescein diacetate fluorescence and reverse transcription-quantitative polymerase chain reaction analysis, respectively. Combination index (CI) analysis was performed to determine whether effects were synergistic (CI<1). The combination treatment was found to synergistically inhibit MDS SKM-1 cell growth, induce cell apoptosis, increase ROS levels, upregulate the expression levels of Bax and caspase-3, and downregulate the mRNA expression of Bcl-2. In conclusion, the combination treatment of As₂O₃ and TL synergistically induced apoptosis in the MDS SKM-1 cells.

[Differentiation of K562 Cells Induced by Pulsatilla Saponin A into Erythroid Lineage]

OBJECTIVE

To explore the differentiation-inducing potentiality of Pulsatilla saponin A on K562 cells.

METHODS

Pulsatilla saponin A of different concentrations was used to treat K562 cells; the benzidine staining and the hemoglobinometry were applied to measure the change of hemoglobin content; the flow cytometry (FCM) was used to detect the expression of CD71 and GPA on K562 cells.

RESULTS

K562 cells treated with 4 µg/ml pulsatilla saponin A differentiated into the erythroid lineage. With the treatment of pulsatilla saponin A, the hemoglobin content in K562 cells increased significantly; CD71 and GPA expression on the K562 cell surface were up-regulated.

CONCLUSION

Pulsatilla saponin A can induce K562 cells to differentiate into erythroid lineage.

High expression of S100A8 gene is associated with drug resistance to etoposide and poor prognosis in acute myeloid leukemia through influencing the apoptosis pathway

S100A8 has been increasingly recognized as a biomarker in multiple solid tumors and has played pivotal roles in hematological malignancies. S100A8 is potentially an indicator for poor survival in acute myeloid leukemia (AML) in retrospective studies. However, the mechanisms of S100A8 are diverse in cancers. In this study, we investigated the correlation of S100A8 at the transcription level with clinical parameters in 91 de novo AML patients and explored its mechanisms of chemoresistance to etoposide in vitro. The transcription level of S100A8 was significantly lower at initial and relapse stages of AML samples than at complete remission (P<0.001) and than in the control group (P=0.0078), while no significant difference could be found between initial and relapse stages (P=0.257). Patients with high transcription levels of S100A8 exhibited a shorter overall survival (P=0.0012). HL-60 cells transfected with S100A8 showed resistance to etoposide with a higher level IC50 value and lower apoptosis rate compared with HL-60 cells transfected with empty vector. Thirty-six genes were significantly downregulated and 12 genes were significantly upregulated in S100A8 overexpression group compared with control group in which 360 genes involved in apoptotic genes array were performed by real-time reverse transcriptase polymerase chain reaction. Among them, the caspase-3, Bcl-2, and Bax were verified by Western blot analysis which indicated that the role of S100A8 in resistance to chemotherapy was closely related with antiapoptosis. In conclusion, critical S100A8 provided useful clinical information in predicting the outcome of AML. The main mechanism of S100A8 which promoted chemoresistance was antiapoptosis.

[Autophagy Activity of CD34+ Cells in MDS Patients and Its Clinical Significance]

OBJECTIVE

To explore the autophagy activity of CD34+ cells in bone marrow of MDS patients and its clinical significance.

METHODS

The activity of autophagy in bone marrow CD34+ cells from 20 MDS patients, 20 non-malignant anemia patients and 5 AML patients admitted in our hospital from October 2012 to March 2014 was detected by flow cytometry (FCM).

RESULTS

The autophagy activity in low risk MDS patients and non-malignant anemia patients were both significantly higher than that in both high risk MDS and AML patients (P<0.05), and more interestingly, the autophagy activity in MDS negatively correlated with World Health Organization classification-based prognostic system (WPSS) score (r=-0.877) .

CONCLUSION

The autophagy activity CD34+ cells in the patients with MDS is higher than that in AML patients, and negatively correlated with WPSS scores, indicating that the decrease of autophagy activity maybe accelerate the genesis and development of MDS and relate with the prognosis of MDS patients.

[Clinical and Laboratorial Characteristics of Primary Acute Myeloid leukemia with Philadelphia Chromosome and Inversion 16]

OBJECTIVE

To summarize the clinical characteristics as well as diagnosis and treatment in 1 case of acute myeloid leukemia(AML) with coexpression of Ph and inv(16).

METHODS

A series of clinical tests, the cellular morphological, immunological, cytogenetic and molecular biological examinations of leukemia cells were performed.

RESULTS

The clinical characteristics of this patient were very common. The cellular morphology is similar to the AML with inv(16). The leukemia cells were stained positively for CD13, CD33, CD34, CD117 and HLA-DR. Karyotypic analysis showed a complex chromosome abnormality including inv(16) and Ph, and the FISH analysis showed that the percentage of rearrangement of CBFβ allele was over that of the BCR-ABL fusion signals. The obvious adverse events did not occur in this patient within 3 years.

CONCLUSION

Ph as secondary aberration of inv(16) rarely occures in primary AML cases, and so far there have not been the clear criteria of diagnosis and treatment. The cytogenetic and molecular biology could provide the basis for diagnosis. Moreover, autologous hematopoietic stem cell transplantation combined with imatinib probably is one of the effective treatment methods.

[Correlation between expression of SIL-TAL1 fusion gene and deletion of 6q in T-cell acute lymphoblastic leukemia]

The present study was designed to investigate the prevalence and clinical significance of SIL-TAL1 rearrangements in T-cell acute lymphoblastic leukemia (T-ALL). The incidence of SIL-TAL1 rearrangements was analyzed by nest real-time quantitative polymerase chain reaction (RT-PCR) in 68 patients with T-ALL. Karyotypic analysis was performed by conventional R-banding assay and array-based comparative genomic hybridization (array-CGH). The results showed that SIL-TAL1 rearrangements were identified in 10/26 (38.5%) pediatric and 2/42 (4.8%) adult T-ALL cases, which indicate a pediatric preference for SIL-TAL1 rearrangements in T-ALL. Two different transcripts were detected in 6/12(50%) T-ALL samples. Abnormal karyotypes were detected in 6 out of 11 cases (54.5%) and a deletion of the long arm of chromosome 6 was observed in 4 cases. Array-CGH results of 2 T-ALL cases with SIL-TAL1 rearrangement revealed that this fusion gene was resulted from a cryptic deletion of 1p32, and the overlap region of 6q deletion was 6q14.1-16.3. These cases with SIL-TAL1 fusion had a higher white blood cell (WBC) count and higher serum levels of lactate dehydrogenase (LDH) than cases without SIL-TAL1 fusion. It is concluded that SIL-TAL1 rearrangements are associated with loss of heterozygosity of chromosomal 6q, and SIL-TAL1-positive patients are younger than SIL-TAL1-negative patients. In contrast to the cases without SIL-TAL1 fusion, there are many adverse prognostic factors in the cases with SIL-TAL1 fusion, such as higher WBC count and higher LDH levels.

[Frequently ABL kinase domain G:C→A:T mutation and uracil DNA glycosylase abnormal expression in TKI-resistant acute lymphoblastic leukemia of Chinese population]

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.

[Expression of autophagy related gene Beclin1 in myelodysplastic syndrome patients and its significance]

This study was aimed to explore the contribution of autophagy associated gene Beclin1 in the prognosis of myelodysplastic syndrome (MDS) by detecting the expression level of Beclin1 in bone marrow mononuclear cells (BMNC) from 40 MDS patients, 14 non-malignant anemia patients and 25 AML patients. The expression of Beclin1 mRNA was detected by real-time quantitative polymerase chain reaction (qRT-PCR). At the same time, the Western blot was used to analyze the expression of Beclin1 proteins. The results showed that the expression of Beclin1 in low risk MDS patients and non-malignant anemia patients was both significantly higher than that in acute myeloid leukemia patients (P < 0.01). And more interestingly, the Beclin1 mRNA expression in MDS group was negatively correlated with World Health Organization classification-based prognostic system (WPSS) score (r = -0.495). It is concluded that the expression of Beclin1 in the patients with MDS is higher than that in AML patients, and negatively correlated with WPSS scores. Beclin1 is a potential biomarker for predicting prognosis of the patients with MDS.

[Effect of AML1-ETO fusion protein on the expression of BCL-2]

This study was aimed to investigate the effect of AML1-ETO fusion protein on the anti-apoptotic gene BCL-2 in leukemic cells and to explore its role in leukemogenesis. The apoptotic levels of U937-WT, U937-Mock and U937-A/E1-4 cells were examined by flow cytometry. And cleaved caspase-3 protein expression was detected by Western blot. BCL-2 gene expression both in AML1-ETO-expressing cells or U937 nonexpressing cells and in leukemia cells of AML patients with or without t(8;21) was assessed by quantitative PCR. The chromatin immunoprecipitation (ChIP)-based PCR was used to investigate the direct interaction between the AML1-ETO and BCL-2 promoter in AML1-ETO positive leukemia cell line. The results indicated that in U937-A/E cells but not in U937-WT or U937-Mock cells, apoptotic cells statistically significantly increased, and AML1-ETO expression also significantly enhanced activation of caspase-3. AML1-ETO-expressing cell subclones displayed significantly low levels of BCL-2 mRNA in comparison with the non-transfected U937. In primary bone marrow cells of acute myeloid leukemia containing AML1-ETO, levels of BCL-2 mRNA were markedly lower as compared with other acute myeloid leukemias lacking this translocation. The enriched regions in transfected cells were located within BCL-2 promoter. It is concluded that BCL-2 is the direct target gene of AML1-ETO. AML1-ETO can down-regulate the expression of BCL-2.

[Clinical significance of common leukemia gene mutations in patients with acute promyelocytic leukemia]

This study was aimed to explore whether multiple common gene mutations of leukemia synergistically involved in acute promyelocytic leukemia (APL) pathogenesis, and to investigate their relevance to clinical features, cytogenetics and molecular risk stratification. 84 specimens of admitted de novo APL patients from February 2005 to October 2010 were collected, the gene mutations of bone marrow mononuclear cells and clinical features of mutation-positive patients were analyzed by genomic DNA-PCR. The results indicated that the prevalence of mutations was 60.7% (51/84), in which the mutations with the highest incidence were found as FLT3-ITD, reaching 27.4% (23/84). Next, there were 12 cases WT1 mutation, 9 for FLT3-TKD, 7 for TET2, 5 for N-RAS, 4 for ASXL1, 2 for EZH2 mutation and 1 positive case in MLL-PTD, IDH1 and CBL mutation respectively. No mutation was found in other JAK1, DNMT3, c-Kit, NPM1, IDH2, RUNX1 and JAK2 (V617F) common leukemia-related genes. Combined analysis with clinical data demonstrated that the patients with FLT3-ITD mutation displayed higher white blood cell counts, while the patients with N-RAS mutation showed lower platelet counts. Overall survival of these patients was obviously shorten as compared with patients with wild-type. This difference between mutant and wild-type of all above mentioned cases was statistically significant (P < 0.05). The difference between APL with simple t (15;17) and additional abnormal karyotype was not statistically significant. It is concluded that the FLT3-ITD mutation is recurrent genetic change in APL, and together with N-RAS mutation indicates poor prognosis. Additional abnormal karyotype does not associate with prognosis of APL.

[Clinical and laboratorial analysis for 15 adult cases of mixed phenotypic acute leukemia with Ph chromosome and/or positive BCR-ABL]

The purpose of this study was to summary the clinical and laboratorial features in 15 adult cases of mixed phenotypic acute leukemia with Ph chromosome and/or BCR-ABL fusion gene positive (Ph(+)MPAL), 15 adult patients with Ph(+)MPAL were defined by WHO-2008 classification. The clinical characteristics, results of morphology, immunology, cytogenetics and molecular genetic detections and results of follow-up in 15 adult patients with Ph(+)MPAL were analyzed retrospectively. The results showed that 15 patients among 87 cases of MPAL demonstrated Ph(+)MPAL (17.2%; 15/87) (7 males and 8 females), their median age was 51 (range 16-81) year old and median WBC count at diagnosis was 69 (12.7-921)×10(9)/L. Based on FAB criteria, these patients showed different morphologic types, including AML (13.3%; 2/15), ALL (40.0%; 6/15), HAL (46.7%; 7/15). Immunologic analysis indicated that 15 cases of Ph(-)MPAL were all classified as B-lymphoid +myeloid mixed immunophenotype. Except one patient, all expressed CD34 antigen on the surface of leukemia cells with 64.3% strong positive, only Ph (53.3%; 8/15), Ph with additional chromosomal abnormalities (33.3%; 5/15) and normal karyotype (13.3%; 2/15) were cytogenetically identified. BCR-ABL fusion gene transcript positive were detected by multiplex reverse transcription PCR in all cases, with e1a2 subtype (p190) (40.0%; 6/15) and b2a2 or b3a2 (p210) subtype (60.0%; 9/15). Four out of 7 (57.1%) patients were found to have IKZF1 gene deletion, without other common gene mutations. Seven out of 10 cases (70.0%) achieved complete remission (CR) after one cycle of induction chemotherapy. In the induction stage, CR rate seemed higher when tyrosine kinase inhibitors (TKI) were added to chemotherapy (83.3%:50.0%; P = 0.206). Overall survival (OS) in 4 patients received allogeneic hematopoietic stem cell transplantation (allo-HSCT) was longer than that in 4 patients received chemotherapy alone (P = 0.004). It is concluded that Ph(+)MPAL mainly is expressed as B+My phenotype. The majority of patients is older and has CD34 overexpression. In the aspect of molecular genetics, the Ph(+)MPAL is similar to other acute leukemia with Ph chromosome. Ph(+)MPAL is a subtype of acute leukemia with poor prognosis. WBC count at diagnosis is an independent prognostic factor. The combination of TKI and allo-HSCT can improve their long-term survival, which needs to be confirmed through carrying out a prospective and multicenter clinical trial for newly diagnosed Ph(+)MPAL.

Growth and differentiation effects of Homer3 on a leukemia cell line

The Homer protein family, also known as the family of cytoplasmic scaffolding proteins, which include three subtypes (Homer1, Homer2, Homer3). Homer3 can regulate transcription and play a very important role in the differentiation and development for some tissues (e.g. muscle and nervous systems). The current studies showed that Homer3 abnormal expression changes in acute myeloid leukemia (AML). Forced expression of Homer3 in transfected K562 cells inhibited proliferation, influenced the cell cycle profile, affected apoptosis induced by As2O3 through inhibition of Bcl2 expression, and also promoted cell differentiation induced by 12-O-tetra decanoylphorbol-acetate (TPA). These results showed that Homer3 is a novel gene which plays a certain role in the occurrence and development of AML.

MicroRNA-375 targets the 3-phosphoinositide-dependent protein kinase-1 gene in pancreatic carcinoma

Pancreatic carcinoma (PC) is an aggressive malignancy with one of the poorest mortality rates. It is the sixth leading cause of mortality from malignant disease in China and the fourth leading cause of cancer-related mortality in the United States. The poor outcome reflects the requirement for an improved understanding of the transcriptional control of oncogenic signaling pathways. 3-phosphoinositide-dependent protein kinase-1 (PDK1) is a potent oncogenic driver of PC. The present study aimed to elucidate the transcriptional regulation of microRNA (miR)-375-targeted PDK1. miR-375 is a putative target and, in the present study, was observed to be significantly downregulated in the tumor compared with non-tumor tissues from patients with PC (n=44). As determined by a luciferase reporter assay, the ectopic expression of miR-375 was identified to diminish the transcriptional activity of PDK1. Furthermore, immunoblotting revealed that miR-375 suppressed endogenous PDK1 protein levels. Functional assays showed that miR-375 was able to inhibit proliferation and promote apoptosis of the PC cells. miR-375 is a significant regulator of the PDK1 oncogene, suggesting that it may have a potential therapeutic role in the treatment of PC.

[Transfection of HL-60 cells by Venus lentiviral vector]

In order to study the potential of Venus, lentiviral vector, applied to acute myeloid leukemia, the recombinant vector Venus-C3aR was transfected into 293T packing cells by DNA-calcium phosphate coprecipitation. All virus stocks were collected and transfected into HL-60, the GFP expression in HL-60 cells was measured by flow cytometry. The expression level of C3aR1 in transfected HL-60 cells was identified by RT-PCR and flow cytometry. The lentiviral toxicity on HL-60 was measured by using CCK-8 method and the ability of cell differentiation was observed. The results indicated that the transfection efficacy of lentiviral vector on HL-60 cells was more than 95%, which meets the needs for further study. C3aR1 expression on HL-60 cells increased after being transfected with recombinant lentiviral vector. Before and after transfection, the proliferation and differentiation of cells were not changed much. It is concluded that the lentiviral vector showed a high efficacy to transfect AML cells and can be integrated in genome of HL-60 cells to realize the stable expression of interest gene. Meanwhile, lentiviral vector can not affect HL-60 cell ability to proliferate and differentiate.

Epigenetic silencing of Bcl-2, CEBPA and p14(ARF) by the AML1-ETO oncoprotein contributing to growth arrest and differentiation block in the U937 cell line

The AML1-ETO fusion transcription factor generated by the t(8;21) translocation is considered to deregulate the expression of genes that are crucial for normal differentiation and proliferation of hematopoietic progenitors, resulting in acute myelogenous leukemia by recruiting co-repressor complexes to DNA. To investigate the role of AML1-ETO in leukemogenesis, we transfected the cloned AML1-ETO cDNA and expressed the AML1-ETO protein in U937 myelomonocytic leukemia cells. By focusing on the anti-apoptotic gene Bcl-2, the key regulator gene of granulocytic differentiation CCAAT/enhancer-binding protein α (CEBPA) and the tumor suppressor gene p14(ARF), we found that both AML1-ETO-expressing cell lines and t(8;21) leukemia samples displayed low levels of these three genes. Chromatin immunoprecipitation assays demonstrated that Bcl-2, CEBPA and p14(ARF) were direct transcriptional targets of AML1-ETO. The universal binding of AML1-ETO to genomic DNA resulted in recruitment of methyl-CpG binding protein 2 (MeCP2), reduction of histone H3 or H4 acetylation and increased trimethylation of histone H3 lysine 9 as well as lysine 27 indicating that AML1-ETO induced heterochromatic silencing of Bcl-2, CEBPA and p14(ARF). These results suggested that the aberrant transcription factor AML1-ETO epigenetically silenced the function of the Bcl-2, CEBPA and p14(ARF) genes by inducing repressed chromatin configurations at their promoters through histone modifications.

[Construction of venus vector carrying IGFBP7 gene and its expression in K562 cells]

The aim of this study was to construct venus vector carrying the gene encoding insulin-like growth factor binding protein 7 (IGFBP7), which provides an effective platform for exploring the function of this gene in leukemia. After digestion by restriction endonuclease, the IGFBP7 gene was recombined with the transfer plasmid. The venus particles were packaged using 293T cells to transfect K562 cells, and identification was performed by means of flow cytometry, RT-PCR and Western blot. The results showed that the sequence of cloned IGFBP7 gene was the same as that in GenBank. The size of product restricted by BamHI was same as the predicted one. GFP expression was observed in 293T and K562 cells with the fluorescent microscopy and flow cytometry. The expression level of mRNA and protein of IGFBP7 was confirmed by RT-PCR and Western blotting in K562 cells. It is concluded that venus vector carrying IGFBP7 gene has been successfully constructed and provides basis for exploring function of IGFBP7 in K562 cells.

A study of the suppressive effect on human pancreatic adenocarcinoma cell proliferation and angiogenesis by stable plasmid-based siRNA silencing of c-Src gene expression

The non-receptor protein tyrosine kinase c-Src regulates diverse biological processes by associating with multiple signaling and structural molecules. Overexpression of c-Src occurs in pancreatic cancer and can be predictive of poor prognosis. The aim of this study was to investigate the inhibitory effects of plasmid-based siRNAs targeting the human c-Src gene on proliferation and angiogenesis in the human pancreatic adenocarcinoma cell line Panc-1. Three siRNAs targeting the c-Src gene were transfected into the Panc-1 pancreatic adenocarcinoma cell line mediated by Lipofectamine. Transfection efficiency was assessed by flow cytometry. Real-time quantitative PCR (RQ-PCR) was employed to detect the expression of c-Src mRNA, and the most effective siRNA was chosen to be cloned into a plasmid. Two single-strand DNA templates were designed according to the most effective siRNA sequences. The short hairpin RNA (shRNA) plasmid targeting c-Src with pGPU6/green fluorescent protein (GFP)/Neo vector psiRNA-c-Src was constructed. Sequencing was performed to check whether the plasmid was constructed correctly. Panc-1 cells were transfected with psiRNA-c-Src and the negative control plasmid (psiRNA-N), respectively. Following selection with G418, the transfected monoclonal cells were chosen. GFP was evaluated by flow cytometry and fluorescence microscopy to estimate transfection efficiency. RQ-PCR and western blotting were used to detect c-Src silencing efficiency. To verify the effects of gemcitabine chemoresistance of c-Src expression, MTT assay was performed. ELISA was used to determine VEGF levels in culture supernatants. In a nude mouse model, tumor growth was studied, c-Src, VEGF expression and microvessel density in tumor tissue were measured by immunohistochemistry. The transfection efficiency of siRNA in the Panc-1 cell line was above 90%, the most effective siRNA could suppress expression of the c-Src gene with an inhibition efficiency of 86.1%. Sequencing confirmed that the c-Src siRNA plasmid was successfully constructed. MTT assay indicated that the effect of gemcitabine-induced cytotoxicity was markedly increased in the psiRNA-c-Src group (P<0.05). Meanwhile, the expression of VEGF in vitro was reduced significantly (P<0.05) in the psiRNA-c-Src group. In nude mice bearing tumors, c-Src, VEGF expression and MVD were decreased in tumors produced from psiRNA-c-Src transfected cells (P<0.05). In summary, the siRNA expression constructs targeting c-Src could specifically suppress c-Src expression, inhibit VEGF expression, inhibit cell proliferation and enhance gemcitabine chemosensitivity in vitro. C-Src gene silencingwas able to inhibit angiogenesis of tumors in vivo. These findings demonstrate that the c-Src targeting gene silencing approach has the potential to serve as a novel tool for pancreatic carcinoma treatment.

[Preliminary establishment of transplanted human chronic myeloid leukemia model in nude mice]

Chronic myeloid leukemia (CML) is a malignant clonal disease derived from hematopoietic stem cells. CML stem cells were thought to be the root which could lead disease development and ultimately rapid change. However, a stable animal model for studying the characteristics of CML stem cells is currently lacking. This study was aimed to establish a transplanted human CML nude-mice model to further explore the biological behavior of CML stem cells in vivo, and to enrich CML stem cells in nude mice by series transplantation. The 4 - 6 weeks old BALB/c nude mice pretreated by splenectomy (S), cytoxan intraperitoneal injection (C) and sublethal irradiation (I) were transplanted intravenously with (5 - 7) × 10(7) of bone marrow mononuclear cells from CML patients in chronic phase. Alternatively, 4 - 6 weeks old BALB/c nude mice pretreated by lethal irradiation were transplanted intravenously with 5 × 10(6) homologous bone marrow cells of BALB/c nude mice together with (5 - 7) × 10(7) of bone marrow mononuclear cells from CML patients in chronic phase simultaneously. The leukemic cells engrafted and infiltrated in organs and bone marrow of the mice were tracked by reverse transcription-polymerase chain reaction (RT-PCR), plastic-embedded biopsy and flow cytometry. The results of these two methods were compared. The results showed that human CML cells engrafted and infiltrating into the bone marrow of two nude mice pretreated with SCI could be detected. In spite of the low successful rate, results suggested the feasibility of this method by using BALB/c nude mice as a human CML animal model. In contrast, in nude mice pretreated by the lethal dose irradiation, CML cells in the bone marrow could not be found. It is concluded that human bone marrow CML cells can results in leukemia in nude mice pretreated by SCI. Thus this study provides a new strategy for establishment of CML animal models which deserves further elaboration.

Effects of forced running exercise on cognitive function and its relation to zinc homeostasis-related gene expression in rat hippocampus

Voluntary exercise has been implicated to be beneficial for overall health and cognitive function in both clinical and experimental studies, but little is presently known about forced physical exercise on cognition and underlying molecular mechanism. We have used real-time RT-PCR to analyze gene expression in hippocampus, in the presence and absence of physical exercise, during spatial learning of rats in the Morris water maze. Our results show distinct zinc homeostasis-related gene expression profiles associated with learning and memory. Rats with physical exercise (EXP) showed a significant up-regulation of mRNA expression of zinc transporter-2 (ZnT-2), ZnT-4, ZnT-5, ZnT-6, and ZnT-7, metallothionein-1 (MT-1)-MT-3, divalent cation transporter-1, and Zrt-Irt-like proteins-7 in hippocampus when compared with control rats. In addition, spatial learning ability was improved in EXP rats compared with that in control group. This study provides the first comparative view of zinc homeostasis-related gene expression in hippocampus following forced physical exercise. These results suggested that forced physical exercise may provide a simple means to maintain brain function and promote learning capacity. Results of this study also suggest that exercise mobilizes zinc homeostasis-related gene expression profiles that would be predicted to benefit brain plasticity processes.

[Expressions of survivin and the splice variants survivin-2B and survivin-DeltaEx3 in bladder cancer and their clinical significance]

BACKGROUND AND OBJECTIVE

Studies on survivin over the past 5 years have shown that survivin participates in the genesis of several human cancers, including bladder cancer. Recent studies have indicated that survivin splice variants appeared to have unique subcellular localizations and functions as well. This study was to explore the roles of survivin and its two splice variants survivin-2B and survivin-DeltaEx3 in transitional cell carcinoma of bladder (BTCC).

METHODS

The relative amount of survivin, survivin-2B, and survivin-DeltaEx3 mRNA of fresh carcinoma tissues from 60 patients with BTCC and 12 non-cancerous bladder tissues were detected by real-time quantitative reverse transcription polymerase chain reaction (RT-PCR), and the relationships of their expression levels in different pathologic grades to clinical stages of bladder cancer were analyzed. The time of follow-up was 4-24 months.

RESULTS

Survivin, survivin-2B, and survivin-DeltaEx3 mRNA were detected in all BTCC tissues, and their relative expressions were 0.333+/-0.163, 0.056+/-0.017, and 0.124+/-0.096, respectively. In the control group,three and four samples expressed survivin and survivin-DeltaEx3 mRNA respectively, and all samples expressed survivin-2B mRNA. The expressions of survivin and survivin-DeltaEx3 mRNA were positively correlated with the pathologic grades and clinical stages (0 < r 's < 1,P < 0.05), however, survivin-2B mRNA was negatively correlated with those (-1 < r 's < 0, P < 0.05).

CONCLUSION

Detecting the expression levels of survivin and its two splice variants survivin-2B and survivin-DeltaEx3 mRNA in BTCC by real-time PCR could have potential values to evaluate tumor progression and recurrence rate.

[Construction of AML1-ETO eukaryotic expression vector and its effects on proliferation and differentiation of U937 cells]

OBJECTIVE

To construct a pcDNA3.1-AML1-ETO expression vector and investigate its effects on proliferation and differentiation of U937 leukemic cells.

METHODS

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.

RESULTS

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).

CONCLUSION

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.

[Effects of simvastatin on proliferation and apoptosis of acute monocytic leukemia cell line SHI-1]

The purpose of this study was to investigate the effect of simvastatin (SIM) on proliferation and apoptosis of acute monocytic leukemia cell line SHI-1 and its mechanism. Experiments were divided into control and test groups (5 µmol/L, 10 µmol/L, 20 µmol/L SIM groups). The growth inhibitory rate of SHI-1 cells was detected using methyl thiazolyl tetrazolium (MTT) method. The cell cycle distribution and apoptotic rate were measured by using flow cytometry. The expression of BCL-2, caspase-3 mRNA were determined by reverse transcription polymerase chain reaction (RT-PCR). The expression of BCL-2, caspase-3 protein levels were analyzed by Western blot. The results demonstrated that SIM inhibited the growth of SHI-1 cells in time- and does-dependent manners. Cell cycle analysis showed that SHI-1 cells significantly arrested in S phase (p < 0.05) after treating with SIM for 48 hours, as compared with control group. 5 µmol/L SIM in test group significantly blocked cell cycle progression, but can not induce apoptosis. The expressions of BCL-2 mRNA and protein were down-regulated and caspase-3 mRNA and protein were up-regulated along with the increase of SIM concentration (p < 0.05). It is concluded that SIM is able to inhibit proliferation and induce apoptosis of SHI-1 cells, the mechanism may be associated with downregulating the expression of apoptosis-related gene BCL-2, upregulating the expression of caspase-3.

GKLF transfection inhibits the growth of xenograft tumors derived from human gastric carcinoma cell line SGC-7901 in nude mice

AIM: To investigate the effects of transfection of the gut-enriched Krüppel-like factor (GKLF) gene on the growth of xenograft tumors derived from human gastric carcinoma cell line SGC-7901 in nude mice and to explore the potential role of the GKLF gene in gastric carcinogenesis.

METHODS: A recombinant plasmid carrying the GKLF gene (pcDNA3.1-GKLF) was transfected into SGC-7901 cells by lipofectin-mediated method. Cells stably expressing the GKLF gene were selected using G418. SGC-7901 cells untransfected and those transfected with empty pcDNA3.1 plasmid were used as controls. A xenograft tumor model was then established. Tumor growth was monitored. Tumor histopathological changes were determined by hematoxylin and eosin (HE) staining. The expression of GKLF and Ki-67 proteins in xenograft tissue was detected by immunohistochemistry.

RESULTS: Compared with the SGC7901-pcDNA3.1 and SGC-7901 groups, the period of latency was significantly lengthened in the SGC7901-pcDNA3.1-GKLF group (14.67 d ± 3.08 d vs 8.33 d ± 1.03 d, 8.67 d ± 1.03 d, both P < 0.05). The weight of xenograft tumors in the SGC7901-pcDNA3.1-GKLF group was significantly lower than that in the SGC7901-pcDNA3.1 and SGC-7901 groups (4.46 g ± 0.92 g vs 8.05 g ± 1.66 g, 7.82 g ± 1.14 g, both P < 0.05). The degree of tumor differentiation in the SGC7901-pcDNA3.1-GKLF group was better than that in the other two groups. Furthermore, the positive proportion of GKLF protein expression in xenograft tissue was increased while that of Ki-67 protein expression was decreased in the SGC7901-pcDNA3.1-GKLF group when compared with the other two groups (4/6 vs 2/6, 2/6; 1/6 vs 4/6, 4/6).

CONCLUSION: Transfection of the GKLF gene inhibits the growth of subcutaneous xenograft tumors derived from SGC-7901 cell line in nude mice by down-regulating the expression of Ki-67. The GKLF gene is a potential target for gene therapy of gastric carcinoma.

[Effect of TIMP-2, MT1-MMP and MMP-2 expression on the in vitro invasive capacity of acute monocytic leukemia SHI-1 cells]

OBJECTIVE

To study the effect of matrix metalloproteinase 2 (MMP-2), membrane type 1 MMP (MT1-MMP) and tissue inhibitor of metalloproteinase 2 (TIMP-2) expressions on the in vitro invasive capacity of acute monocytic leukemia SHI-1 cells.

METHODS

SHI-1, NB4, K562, M937 and THP-1 human leukemia cell lines were cultured in vitro. The mRNA and protein expressions of TIMP-2, MMP-2 and MT1-MMP in different cells were detected by quantitative RT-PCR and western blot. A retroviral vector carrying human TIMP-2 cDNA was constructed and transfected into SHI-1 cells. Three subclone cells (S1, S2 and S3) were screened by G418 and selected by limiting dilution. RNA interference (RNAi) was used to knock down the expression of MMP-2, MT1-MMP and TIMP-2. Cell invasion capacity was performed through a reconstituted human basement membrane assays. Zymography was used to analyze the expression of MMP-2 in the supernatant of co-culture.

RESULTS

The expressions of MMP-2, MT1-MMP and TIMP-2 in SHI-1 cells were higher than that in other leukemic cells at both mRNA and protein levels (P < 0.05). The amount of proMMP-2 and activated MMP-2 in the conditioned media from SHI-1 cells co-cultured with bone marrow stromal cells (BMSCs) was more than that from other cells (P < 0.05). The in vitro invasive capacity of SHI-1 cells were higher than that of other cells (P < 0.05). The mRNA levels of TIMP-2 were increased by about 3 fold, 2 fold and 1.5 fold in S1, S2 and S3 cells, respectively (P < 0.05), while the protein levels were by about 2.6 fold, 1.5 fold and 1.3 fold than that of SHI-1 cells, respectively (P < 0.01). The invasion rates of subclone cells demonstrated a 1.5 - 2.5 fold' elevation (P < 0.05) and activated MMP-2 from their supernatants increased by 1.5 - 2.0 fold (P < 0.01). The knock-down efficiency of siRNA was 85% to 98%. The down-regulation of TIMP-2, MMP-2 and MT1-MMP decreased the invasion rates of SHI-1 cells by 60% - 70%, 50% - 60% and 40% - 50%, respectively (P < 0.05). No activated MMP-2 in the supernatants from any knock-down cells could be found.

CONCLUSIONS

SHI-1 cells constitutively overexpress MMP-2, MT1-MMP and TIMP-2 at both mRNA and protein levels. After co-cultured with BMSCs the SHI-1 cells increased MMP-2 activation and cell invasion. An increase of TIMP-2 expression in SHI-1 cells reflects an activating effect on cells invasion and MMP-2 activation.

[Influence of arsenic trioxide and daunorubicin on the expression of annexin II and fibrinolytic activity in NB4 cells]

OBJECTIVE

To study the expression of annexin II (AnnII) and the fibrinolytic activity in NB4 cells and their alterations in the presence of arsenic trioxide (ATO) and daunorubicin (DNR).

METHODS

Leukemia cell line NB4 was treated with ATO or DNR for 24 ∼ 72 h. Cell surface expression of AnnII and its mRNA were analysed by flow cytometry and real time PCR, respectively, the fibrinolytic activity by chromogenic assay.

RESULTS

Compared with other acute leukemia cell lines, the expression of AnnII on untreated NB4 cells was relatively higher. The AnnII positive cell rates on NB4, HL-60, K562, and A3 cells were (94.5 ± 1.6)%, (40.1 ± 2.1)%, (36.3 ± 1.5)% and (11.8 ± 2.5)%, respectively. The fibrinolytic activity of NB4 cells was the greatest with a A value of 0.68 ± 0.02. The fibrinolytic activity of NB4 cells was obviously decreased by ATO, DNR or monoclonal antibody against AnnII, being decreased by 60.4%, 35.8% and 26.0% of the pretreatment level, respectively. The expressions of AnnII and its mRNA in NB4 cells were decreased dramatically after ATO and DNR treated for 48 h. Annexin II positive cells rate were (55.46 ± 4.72)% and (27.00 ± 6.18)%, respectively.

CONCLUSION

NB4 cells have strong ability to enhance the catalytic efficiency of the t-PA-dependent plasminogen activation and AnnII on the cell membrane contributes to this activity. Its high fibrinolytic activity can be corrected by ATO and DNR through down-regulating AnnII.

The significance of detecting WT1 expression in childhood acute leukemias

WT1 (Wilms' tumor gene 1) overexpression is implicated in the prognosis of acute leukemia. The purpose of this study was to investigate WT1 expression and its clinical implication in childhood acute leukemia (AL) in Chinese population. Bone marrow specimen from 200 children at different stages of acute leukemia and from 21 children without leukemia were studied. The WT1 expression at diagnostic marrow specimen in both acute myeloid leukemia (AML) and acute lymphoid leukemia (ALL) was higher than control group, whereas WT1 expression in AML was higher than in ALL, and WT1 expression level in relapse in ALL increased more significantly than in AML. The WT1 expression level showed positive correlation with the hypodiploidy and BCR-ABL fusion gene in acute leukemia. A rapidly decrease of WT1 expression level predicted a good response to the induction therapy and low expression of WT1 correlates with remission status. This study suggested that WT1 expression levels in acute leukemia can potentially be a marker for evaluating therapeutic efficacy, correlating with monitoring minimal residue disease, and predicting hematological relapse in children acute leukemia.

[Expression of growth-factor independence 1 in patients with leukemia and its significance]

This study was purposed to investigate the expression of the growth-factor independence 1 (GFI1) in patients with leukemia and its clinical significance. Bone marrow mononuclear cells were obtained from 65 newly diagnosed leukemia patients including 24 acute myeloid leukemia (AML), 18 chronic myelogenous leukemia (CML), 6 acute lymphoblastic leukemia (ALL), 17 blast crisis of chronic myelogenous leukemia and 13 patients with iron deficiency anemia (IDA) were used as controls. The relative expression of gene gfi1 was detected by reverse transcriptase-polymerase chain reaction (RT-PCR) and taqman quantitative real-time reverse transcription polymerase chain reaction (QRT-PCR). The results showed that gene expression of gene gfi1 in leukemia patients was obviously higher than that in controls and the difference was statistically significant (p < 0.01), in which the expression of gene gfi1 in newly diagnosed CML patients was higher than that in newly diagnosed AML, newly diagnosed ALL, CML-BCP patients and the difference was significant (p < 0.01). Expression of gene gfi1 in lymphocytic blast crisis of CML was higher than that in nonlymphocytic blast crisis of CML, and the difference was significant. It is concluded that gene gfi1 may play an important role in leukemia, especially in CML incidence and progression. The high level expression of gene gfi1 may be participate in the development of lymphoma.

[Assessment of minimal residual disease in adult patients with B-lineage acute lymphoblastic leukemia using rearranged immunoglobulin loci detection]

OBJECTIVE

To explore detection of immunoglobulin heavy chain gene (IgH) rearrangement by real-time quantitative polymerase chain reaction (RQ-PCR) for minimal residual disease (MRD) monitoring in adult B-lineage acute lymphoblastic leukemia (B-ALL) patients.

METHODS

DNA samples of fifteen newly diagnosed adult B-ALL patients were collected. The IgH gene rearrangements were detected by PCR followed by sequencing and subsequent blasting for monoclonal PCR products. Allele-specific oligonucleotides (ASO) were designed based on the sequence of junction regions, using PRIMER 5.0 software. MRD targets were detected in 115 bone marrow samples by RQ-PCR, in which ASO upstream primers in combination with the consensus JH probes and downstream primers were used. Transcripts copies of bcr-abl fusion gene were also measured in 7 Ph(+) ALL cases.

RESULTS

The detection sensitivity of ASO-PCR varied between 10(-3) and 10(-5) leukemia cells in 15 adult ALL patients. The background and nonspecific amplification was detectable at a low level. Quantification monitoring MRD showed that high-risk adult ALL patients in complete remission (CR) had a higher MRD level than those of standard-risk. Patients with MRD > 10(-3) had a higher relapse rate and a shorter survival time. Besids, the dynamic curves of the quantified level of respective IgH rearrangement were consistent with the expression levels of bcr-abl fusion genes in seven Ph(+) patients during follow-up.

CONCLUSIONS

The individual quantification of IgH rearrangement by RQ-PCR using ASO primers was a sensitive, specific and reliable method for accurate evaluation of malignant clones. These data indicates a close correlation between the level of rearranged IgH and the treatment response and prognosis in adult ALL patients. It may be a helpful method for monitoring MRD in clinical trials.

[Apoptosis of chronic myeloid leukemia stem/progenitor cells induced by anti-CD44 monoclonal antibody IM7 in vitro]

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.

[In vitro effects of anti-CD44 monoclonal antibody on the adhesion and migration of chronic myeloid leukemia stem cells]

OBJECTIVE

To explore the effects of anti-CD44 monoclonal antibody-IM7 on the in vitro adhesion and migration of chronic myeloid leukemia stem cell (CML-LSC) and its mechanism.

METHODS

CD34(+)CD38(-)CD123(+) leukemic stem cells (LSC) from 20 newly-diagnosed chronic myeloid leukemia (CML) patients BM cells and CD34(+)CD38(-) hematopoietic stem cells (HSC) from 20 full-term newborn cord blood cells were isolated with EasySep(TM) magnet beads. The CD44 expression of the LSC and HSC was detected by flow cytometry (FCM), and the adhesion and migration ability of the LSC and HSC pre- and post-incubated with IM7 in vitro by MTT assay and transendothelial migration assay, respectively.

RESULTS

(1) After incubated with IM7, the LSC and HSC CD44 expression rates were (86.60 ± 2.10)% vs. (25.40 ± 1.70)% (P < 0.05), respectively. (2) The adhesive ability of the LSC to endothelial cells was decreased markedly after incubated with IM7, the OD value (A(570)) changing from pre-incubation of (0.62 ± 0.11) to post-incubation of (0.34 ± 0.07), while there was little change of A(570) in the HSC group. (3) The migration ability of the LSC group was inhibited evidently after incubated with IM7, the inhibition rate being 46% ∼ 63%, while little change of that in HSC group was detected. (4) The adhesive ability of the LSC group to marrow stromal cells was decreased markedly after incubated with IM7, while little change was found in that of HSC group.

CONCLUSION

The anti-CD44 monoclonal antibody-IM7 can effectively inhibit the adhesion and migration abilities of the LSC in vitro, which might provide a theoretical evidence for targeting therapy.

Hypermethylation downregulates Runx3 gene expression and its restoration suppresses gastric epithelial cell growth by inducing p27 and caspase3 in human gastric cancer

BACKGROUND AND AIMS

Runx family transcription factors are integral components of transforming growth factor-beta signaling pathways and have been implicated in cell cycle regulation, differentiation, apoptosis, and malignant transformation. The silencing of tumor suppressor genes by aberrant hypermethylation occurs frequently in human cancer. It has been noted previously that Runx3 is regarded as an important tumor suppressor gene.

METHODS

Reverse transcription polymerase chain reaction was used to measure Runx3 and the DNA methyltransferase 1 (Dnmt1) messenger RNA (mRNA) expression level of paired samples of primary gastric cancer and corresponding non-cancerous gastric mucosae, which were obtained from surgically resected specimens of 70 patients. Western blot was used to detect the expression of Runx3 at protein levels. The promoter methylation status was measured by using methylation-specific polymerase chain reaction. We used Annexin V-FITC/PI assay to detect cell apoptosis, and the cell cycle was also analyzed. In order to examine the cell cycle and/or apoptosis, we determined p27 and caspase 3 expression by immunohistological analysis.

RESULTS

Our results demonstrate a loss or substantial decrease of Runx3 expression in 70 cases of gastric tumors as compared with that in normal gastric mucosa (0.5749 +/- 0.3580 vs 1.7252 +/- 0.4085, P < 0.05). The protein levels of the Runx3 gene were significantly lower in gastric cancers than those in adjacent normal tissues. The hypermethylation of Runx3 was involved in 50% (28/56) of gastric cancer tissues, which had reduced Runx3 mRNA expression. The differences of the Dnmt1 mRNA level were significant between the methylated and unmethylated Runx3 cancerous groups. Runx3 methylation was significantly correlated with increased Dnmt1 (r = 0.64, P < 0.01). Enforced restoration of Runx3 expression led to the induction of cell apoptosis and upregulation of p27 and caspase3 expression in vitro.

CONCLUSIONS

Our results suggest that a decrease of Runx3 expression by DNA hypermethylation is frequently associated with the evolution of gastric cancer. Runx3 was an independent prognostic factor and a potential therapeutic target for gastric cancer.

[A clinical and laboratory study of TCF3-PBX1 positive adult acute lymphoblastic leukemia.]

OBJECTIVE

To explore the morphology, immunophenotype, cytogenetics and clinical features of TCF3-PBX1 fusion gene positive adult acute lymphoblastic leukemia (ALL).

METHODS

R banding was used to analyze conventional cytogenetics (CC), interphase fluorescence in situ hybridization (iFISH) and RT-PCR to detect the TCF3-PBX1 fusion gene, and flow cytometry to immunophenotype. The clinical and laboratory features and long-term follow-up of the patients were analyzed.

RESULTS

The incidence of 19 TCF3-PBX1-positive adult ALL was 3.13% of total ALL patients. Of them, 12 and 7 cases were diagnosed as L(1) and L(2) morphology respectively; 7 cases with balanced translocation of chromosome 1 and 19; 10 with der(19) t(1;19) formed from unbalanced translocation and 2 with normal karyotypes. TCF3-PBX1 fusion gene was detected by RT-PCR in 9 cases, and by iFISH in 17. 16 cases were B-phenotype and the other 2 T-phenotype; 17 cases had lymph node, spleen or liver infiltration. Of 18 patients received chemotherapy, 17 (94.7%) achieved complete remission (CR); the median relapse-free survival (RFS) and median overall survival was 3.2 months and 7.2 months, respectively.

CONCLUSIONS

TCF3-PBX1-positive adult ALL had unique clinical and pathological features with high remission rate, high relapse rate and short survival time and should be considered to receive intensified treatment strategies. iFISH combined with CC and RT-PCR can increase the detection rate of t(1;19)/TCF3-PBX1 fusion gene.

Accelerated cellular senescence in myelodysplastic syndrome

OBJECTIVE

To investigate the contribution of cellular senescence to the progression and prognosis of myelodysplastic syndrome (MDS).

MATERIALS AND METHODS

We have analyzed the expression of p16INK4a in bone marrow mononuclear cells or CD34(+) cells from 53 patients with MDS, 12 acute myeloid leukemia (AML), and 11 healthy controls. Additionally, We have assessed quantitatively senescence-associated beta-galactosidase (SA-beta-gal) staining on bone marrow mononuclear cells from MDS and AML patients, HL60 and SHI-1 leukemia cell lines, and healthy control cells.

RESULTS

An upregulated expression of senescence-associated molecular marker p16INK4a was found in MDS compared with healthy controls, while a lower expression of p16INK4a was observed in AML compared with healthy controls. International Prognostic Scoring System score was negatively correlated with the percentage of p16INK4a-positive cells. The SA-beta-gal activity measured by mean percentage of positive cells was significantly higher in MDS cases when compared with controls. Meanwhile, percentage of SA-beta-gal-positive cells was also remarkably higher in dysplastic cells of MDS when compared to nondysplastic cells from MDS.

CONCLUSIONS

These results of our present study suggested an accelerated cellular senescence occurred in MDS, and the cellular senescence may be involved in the progression and prognosis of MDS.

[Expression of CYP3A5 mRNA in children with acute leukemia]

OBJECTIVE

The cytochrome P450 subfamily IIIA5 (CYP3A5) gene is responsible for the metabolism of many clinically used anticancer agents. So far the studies on CYP3A5 gene has only been focused on the leukemia cell lines. This study examined the polymorphism of CYP3A5 and tried to find the possible relationship between CYP3A5 gene expression and treatment outcome or prognosis in children with acute leukemia.

METHODS

The genotype distribution of CYP3A5-6986A/G gene polymorphism was detected with the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method in 66 children with newly diagnosed acute leukemia (AL) and 22 control individuals. Quantitative real-time RT-PCR was used to examine wt-CYP3A5 and SV1-CYP3A5 mRNA levels in the bone marrow.

RESULTS

Three genotypes of CYP3A5-6986A/G polymorphisms were found: CYP3A5*1/*1, CYP3A5*1/*3 and CYP3A5*3/*3. There were significant differences in the wt-CYP3A5 mRNA expression among the AL patients with different genotypes (p<0.05). In patients with acute lymphocytic leukaemia (ALL), the complete remission (CR) rate in the group with a low expression of wt-CYP3A5 mRNA was significantly higher than that in the group with a high expression (p<0.05). A dynamic monitoring for wt-CYP3A5 mRNA expression was performed in two cases of ALL. The expression increased before ALL relapse compared with that in CR in a patient, while in the other patient, the expression was kept in a low level and the patient remained in CR CONCLUSIONS: wt-CYP3A5 mRNA expression was associated with the treatment outcome and prognosis in children with AL. Dynamic monitoring for wt-CYP3A5 mRNA expression in the bone marrow may be useful in the evaluation of the disease severity in childhood acute leukemia.