OBJECTIVE: In order to conduct high-throughput genome-wide translocation sequencing based on CRISPR/Cas9, Nalm6-cas9 monoclonal cell line expressing Cas9 protein was constructed by lentivirus transduction. METHODS: Lentiviral vectors LentiCas9-Blast, pSPAX2, and pMD2.G were used to co-transfect HEK293T cells to obtain recombinant lentivirus. After Nalm6 cells were infected with the recombinant lentivirus, the cells were screened by Blasticidin, and multiple monoclonal cell lines expressing Cas9 protein were obtained by limited dilution. Western blot was used to detect the expression level of Cas9 protein in monoclonal cell lines, and cell count analysis was used to detect the proliferation activity of monoclonal cell lines. LentiCRISPRV2GFP-Δcas9, LentiCRISPRV2GFP-Δcas9-AF4, LentiCRISPRV2GFP-Δ cas9-MLL plasmids were constructed, and transfected with pSPAX2 and pMD2.G, respectively. T vector cloning was used to detect the function of Cas9 protein in Nalm6-Cas9 monoclonal cell line infected with virus. RESULTS: Western blot showed that Nalm6-Cas9_1-6 monoclonal cell line had high expression of Cas9 protein. Cell count analysis showed that high expression of Cas9 protein in Nalm6-Cas9_1-6 monoclonal cell line did not affect cell proliferation activity. The Nalm6-Cas9_1-6 monoclonal cell line had high cleavage activity, and the editing efficiency of AF4 and MLL genes was more than 90% which was determined by T vector cloning. CONCLUSION Nalm6-Cas9_1-6 monoclonal cell line stably expressing highly active Cas9 protein was obtained, which provided a basis for exploring the translocation of MLL in therapy-related leukemias based on CRISPR/Cas9 genome-wide high-throughput genome-wide translocation sequencing.
CRISPR-Associated Protein 9/genetics* ; CRISPR-Cas Systems ; Genetic Vectors ; HEK293 Cells ; Humans ; Lentivirus/genetics* ; Plasmids

OBJECTIVE: To study the expression of B lymphocyte-induced mature protein-1 (BLIMP-1) in regulatory T cells (Tregs) of children with aplastic anemia (AA), and analyze its correlation with the number of Tregs and the levels of inhibitory cytokines interleukin (IL)-10 and transforming growth factor (TGF)-β in plasma. METHODS: The peripheral blood samples of 10 newly diagnosed AA children and 10 healthy children were collected for experiment. qPCR was used to detect FOXP3 and PRDM1 mRNA expression levels. Flow cytometry was used to detect the proportion of Tregs, the expression of BLIMP-1 in Tregs, and the levels of cytokines such as IL-2, IL-17A, IL-6, interferon (IFN)-γ, IL-10 and TGF-β in plasma. Pearson correlation model was used to evaluate the relationship between the expression of BLIMP-1 in Treg and the number of Tregs, as well as the levels of IL-10 and TGF-β in plasma. RESULTS: Compared with control group, the proportion of Tregs in peripheral blood of AA children was decreased significantly (P<0.001); The plasma levels of proinflammatory cytokines IL-2, IL-6 and IFN-γ in AA children were increased significantly (P=0.033, P=0.031, P=0.006), and IL-17A also was increased but the difference was not statistically significant (P=0.052), while anti-inflammatory cytokines IL-10 and TGF-β were significantly reduced (P=0.048, P=0.002). The relative expressions level of FOXP3 and PRDM1 mRNA in AA children were significantly lower than those in control group (P=0.037, P=0.016). The expression of BLIMP-1 protein in Tregs of AA children was significantly lower than that in control group (P<0.001). The expression level of BLIMP-1 protein in Tregs was positively correlated with the percentage of Tregs in lymphocytes (r=0.671, P=0.001), and was also positively correlated with the levels of IL-10 and TGF-β in plasma (r=0.500, P=0.029; r=0.486, P=0.030). CONCLUSION The expression of BLIMP-1 in Tregs of AA children is impaired, and the low expression of BLIMP-1 is related to the decrease of the number in Tregs and IL-10 and TGF-β expressions.
Anemia, Aplastic ; Child ; Cytokines ; Flow Cytometry ; Forkhead Transcription Factors ; Humans ; Positive Regulatory Domain I-Binding Factor 1 ; T-Lymphocytes, Regulatory ; Transforming Growth Factor beta

Objective:To investigate the quality of rehabilitation medical service in tertiary general hospitals in Gansu Province. Methods:Stratified sampling was used to sample tertiary general hospitals in Gansu Province for on-site surveys in 2017. A quality evaluation index system was established in the view of medical service providers, including 17 indicators, based on Donabedian model and experts' opinions. Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) and Rank-sum Ratio were applied to make a comprehensive evaluation on the overall service quality of the hospital rehabilitation medical service. Results:A total of 27 tertiary general hospitals were sampled, in 13 cities/prefectures of Gansu Province. For the structure quality, the compliance rate of the business operation area and the number of beds in the rehabilitation medicine department were 77.78% and 51.85% respectively; while the compliance rates of the physicians, therapists and nurses were all less than 50%. For the process and results quality, the compliance rates were all more than 85%. For the overall quality of rehabilitation medical service, five hospitals were classified as Good, located in Lanzhou, Tianshui and Jiayuguan; 18 hospitals were classified as Medium, located in Longnan, Longdong, Lanzhou and surround, Linxia and Hexi regions; four hospitals classified as Poor, located in Lanzhou and Tianshui. Conclusion:The overall quality of rehabilitation services in the tertiary general hospitals of Gansu Province needs to be improved, and the development of rehabilitation services is uneven in various regions. Comprehensive evaluation provides an important reference to promote the rational distribution of rehabilitation medical resources and improve the quality of rehabilitation medical services.

OBJECTIVE: To investigate the effect of etoposide (ETO) on elimination of chronic myeloid leukemia (CML) stem cells by imatinib mesylate(IM) in vivo. METHODS: SCL-tTA/BCR-ABL mice were used as CML animal model. Flow cytometry was used to assess the effect of ETO alone or in combination with IM on the number of leukemia stem cell （LSC） in bone marrow and spleen, and peripheral blood neutrophils in CML mice and normal control FVB mice. RESULTS: The results showed that in CML mice, the number and proportion of LSC in bone marrow and the proportion of neutrophils in peripheral blood decreased significantly after ETO and IM combined treatment, and the degree of decrease was more significant than that of both alone. While in wild type FVB mice, the combination of ETO and IM showed no significant effect on the number and proportion of LSK cells in bone marrow and the proportion of neutrophils in spleen. CONCLUSION ETO can selectively enhance elimination of CML LSC by IM in vivo.
Animals ; Drug Resistance, Neoplasm ; Etoposide ; Fusion Proteins, bcr-abl ; Imatinib Mesylate ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive/drug therapy* ; Mice ; Stem Cells

OBJECTIVETo investigate the potential relationship between the high-resolution HLA-A,-B,-DRB1 alleles and haplotype polymorphism with actute myeloid leukemia (AML) and chronic myeloid leukemia (CML) of Han people in North China.

METHODSA total of 1241 healthy unrelated Han people's bone marrow donors in North China were used as a control group, 259 patients with myeloid leukemia were genotyped at high-resolution level by means of PCR-SBT, -SSO and -SSP typing methods for HLA-A,-B,-DRB1 loci. The frequencies of HLA allele and haplotype were calculated by software Arleguin 3.5.2. The different distribution of genes and haplotypes was analyzed by case control study, and the odd ratio (OR) of leukemia was also calculated. The structural difference of HLA alleles was analyzed 111by HLA three-dimensional structure modeling and software Swiss-PdbViewer v4.1.

RESULTSχtest and correction showed that an increased frequency of A*02:07 (8.47% vs 5.28%, P' =0.013), A*29:01 (1.85% vs 0.68%, P=0.044), B*07:02 (5.29% vs 3.10%, P=0.029), B*07:05:01G (1.85% vs 0.68%, P=0.044) and B*35:02 (1.06% vs 0.20%, P=0.023) were found in AML patients (n=189) as compared with controls, respectively; whereas A*02:03 was less frequent in AML as compared with controls (0.79% vs 3.10%, P=0.011). The frequency of B*46:01 was lower in CML patients (n=70) as compared with controls (2.86% vs 7.82%, P=0.031). However, the above-mentioned discrepancies were not statistically significant by Bonferroni correction. Through Fisher exact test and Bonferroni correction, the frequency of DRB1*11:28 and its haplotype A*24:02-B*15:01-DRB1*11:28 in CML group were very significantly higher than in controls (1.43% vs 0.00%, Pc=0.015; 1.43% vs 0.00%, P=0.003). Three-dimensional structure modeling of DRB1*11:28 and DRB1*11:01 presented significant structure differentiation (RMSD=0.09 nm) in peptide binding region of the backbone calculated by Swiss-PdbViewer v4.1. The haplotype A*03:01-B*50:01-DRB1*07:01 in AML and A*11:01-B*40:06-DRB1*09:01 in CML patients were significantly higher than that in controls (1.06% vs 0.00%, Pc=0.000; 2.86% vs 0.07%, Pc=0.000), and positively correlated with leukemia (OR=59.66, 95% CI=3.21-1110.39; OR=42.91, 95% CI=7.07-260.32).

CONCLUSIONThe relationship of HLA-A,-B,-DRB1 alleles and haplotype polymorphism with leukemia at high-resolution level were obtained and unique in north Chinese Han population. AML and CML patients in Northern Han people carry particular susceptible haplotypes. DRB1*11:28, which might not actively present bcr-abl peptide to CD4T cells, and is a susceptibile gene for CML patients of Northern Han people, especially in Shaanxi Province (OR=89.62, 95% CI=4.28-1875.87), as well as correlated with its particular haplotype.

BACKGROUNDEssential thrombocythemia is a subgroup of myeloproliferative neoplasms. Previous studies identified mutations of JAK2, CALR, and MPL that are closely related with the pathogenesis of myeloproliferative neoplasms. All these mutations contribute to the hyperactivation of JAK2/STAT pathway. However, a small proportion of essential thrombocythemia patients does not display such mutations. The pathogenesis of "triple-negative" form of essential thrombocythemia remains unknown.

OBJECTIVETo investigate the clinical characteristics of triple-negative essential thrombocythemia and related mutation genes.

METHODSTo identify the mutations associated with triple-negative essential thrombocythemia, next-generation sequencing was used to conduct targeted sequencing of 360 genes in samples from 68 patients.

RESULTSAt least one missense mutation was detected in all the patients and all the detected genes. After screening the data, it was observed that 10 genes with the 10 highest mutation were follows: FLT3, SH2B3, ASXL1, ADAMTS1, TET2, TP53, EGFR, CUX1, GATA2, and MPL.When only rare genes (i.e., with a frequency in Asian populations lower than 5%, as estimated by the 1000 Genomes Project) were analyzed, the most frequently mutated genes in the patients were TET2 (33.82%), SH2B3(29.41%), and ASXL1 (23.53%). Our study identified some mutations that did not previously reported. Although all these mutations need further validation, high incidence rates may indicate relevance of the respective mutations to essential thrombocythemia pathogenesis. Some of the detected mutations have been previously reported; these mutations were also found in a large proportion of our subjects.

CONCLUSIONwhole-exon sequencing can provide a higher level of accuracy for gene mutation analysis and assist in identifying mutations that contribute to illustrate the pathogenesis of essential thrombocythemia.

Calreticulin ; DNA Mutational Analysis ; Humans ; Janus Kinase 2 ; Mutation ; Myeloproliferative Disorders ; Receptors, Thrombopoietin ; Thrombocythemia, Essential

OBJECTIVETo explore the anti-myeloma effect of suberoylanilide hydroxamic acid (SAHA) and on mouse myeloma cell line SP2/0 in vitro and in vivo and its mechanism.

METHODSThe inhibitory effect of SAHA on SP2/0 cells was measured by CCK-8 assay,and the apoptosis and cell cycle were analyzed by flow cytometry FACS. The protein expression of Caspase-3 and p53 of SP2/0 cells treated with SAHA were examined by Western blot. Annexin V/7-AAD double staining was performed to detect the apoptosis of SP2/0 induced by SAHA in vitro. SP2/0 cells (1×10) resuspended in 200 µl PBS were inoculated subcutaneously and intravenously into BALB/c mice, so as to establish aggressive or non-aggressive myeloma-bearing mouse models respectively. On day 3 after modeling, mice received SAHA or vehicle control treatment by intraperitoneal injection. The dose of SAHA was 60 mg/kg·d, 5 times a week for 3 weeks.

RESULTSIn SAHA-treated SP2/0 cells, the proliferation inhibition rate and apoptotic cells increased in a dose dependent manner. Also, SAHA significantly increased the ratio of cells in G phase and decreased in S phase. Molecular mechanisms of apoptosis and cell cycle arrest of SP2/0 induced by SAHA partly correlated with up-regulating the expression level of Caspase-3 and p53. In the non-aggressive myeloma-bearing mice, SP2/0 cells disappeared in peripheral blood after SAHA treatment. In the aggressive myeloma-bearing mice, inhibition of tumor growth and prolongation of the cell survival were observed after SAHA treatment.

CONCLUSIONSAHA inhibited SP2/0 cell proliferation, this effect associates with inducing apoptosis and cell cycle arrest, the mechanism of SAHA ralates partly with activating Caspase-3 and p53 pathway.

Animals ; Antineoplastic Agents ; Apoptosis ; Cell Line, Tumor ; Cell Proliferation ; Histone Deacetylase Inhibitors ; Hydroxamic Acids ; Mice ; Mice, Inbred BALB C ; Multiple Myeloma

OBJECTIVETo investigate the clinical efficacy of Fu Fan Huang Dai Pian(RIF) and arsenic trioxide (ATO) regimens for treatment of children with acute promyelocytic leukemia (APL) and to explore the risk factors affecting the prognosis of patients.

METHODSThe clinical data of 45 newly diagnosed APL children admitted in our hospital from January 2004 to May 2017 were analyzed retrospectively. Among 45 APL children, 25 children were treated by chemotherapetic regimen including RIF (RIF group), another 20 children were treated by chemotherapeutic regimen including ATO (ATO group). The follow-up was performed in all APL children. The prognosis and incidence of side reactions from drugs in 2 groups were compared, and the high risk factors affecting the prognosis of patients were analyzed.

RESULTSThe median follow-up time was 49.8% months. In RIF group, no early death occured in 25 APL children; 5 cases did not achieve complete remission (CR) after induction therapy, CR rate was 88%. Out of 25 cases 2 caes relapsed, 3 cases died, 20 cases maintained contined CR (CCR), 2 cases failed to be followed-up. In ATO group, 2 cases suffered from early death, 5 cases did not achieve CR after induction therapy, CR rate was 90%, 2 caese relapsed and died, 15 cases maintained CCR, the follow-up failed in 1 caes. The 5 year- OS and EFS rate in all the patients were predicted as (82.2±6.2)% and (76.4±6.6)% respectively. The OS and EFS rate in RIF group were (86.1±7.4)% and (78.4±8.6)% respectively, which were significantly different from OS and EFS rate (76.4%±10.6%) and (74.0%±10.1%) respectively in ATO group (all P>0.05). As for the side reaction from drug, except for the cardiac damage (P<0.05), incidence of other side reactions was not significantly different between 2 groups (P>0.05). In addition, the 5 year-OS and EFS rates in APL children with CNSL were significantly lower than those in APL children without CNSL (all P<0.05), the 5 year OS and EFS rate in APL children did not reache M1 and with high risk were significantly lower than those in APL children reached M1 after induction therapy and with low and standerd risk (P<0.05 and P<0.05); the 5 year-OS and EFS rates did not correlate with age and sex.

CONCLUSIONThe Fu Fang Huang Dai Pian shows the therapeutic efficacy on APL children same as ATO, moreover, no obvious enhancement in incidence of side reactions is observed, therefore, the Fu Fang Huang Dai Pian is effective and safe for treatment of APL children. The CNSL, poor respond to treatment, high risk in clinical stratification are high risk factors affecting prognosis of patients.

OBJECTIVETo investigate the clinical characteristics and long-term outcome of Chinese young patients (≤40 years) with essential thrombocythemia(ET), and to develop a thrombosis predicting model specific for young patients with ET, so as to provide a new evidence for risk stratification and treatment.

METHODSMedical records of 125 Chinese young patients with newly diagnosed of ET were retrospectively analyzed.

RESULTSThe median age at diagnosis was 32 (18-40) years old, with 37 males and 88 females. During follow-up, 18 patients (14.4%) experienced major thrombotic events. JAK2 V617F (HR=8.895, P=0.001), history of thrombosis (HR=8.001, P<0.001) and WBC≥12.0×10/L (HR=5.225, P=0.002) were independent risk factors for thrombosis. The incidence of thrombosis and risk factors in young patients were different from that in general ET population, so a thrombosis predicting model specific for young patients with ET was developed. In this model, JAK2 V617F (score 2), history of thrombosis (score 2) and WBC≥12.0×10/L (score 1) were used to divide the patients into low risk (score 0), intermediate risk (score 1-2) and high risk (score≥3) groups. These 3 groups exhibited significantly different thrombosis-free survival (χ=32.223, P<0.001). Antiplatelet treatment could prevent the occurrence of thrombosis (HR=0.081, P<0.001), while cytoreductive agents significantly decreased the risk of thrombosis only in intermediate and high risk groups (14.3% vs 36.4%, χ=4.416, P=0.036). Seven patients (5.6%) evolved to myelofibrosis, and one of them finally progressed in to acute leukemia. The only risk factor for evolution was WBC≥15.0×10/L (χ=5.434, P=0.020). Neither antiplatelet treatment nor cytoreductive agents could prevent disease progression.

CONCLUSIONThe incidence of thrombosis and risk factors in young patients with ET are different from that in general ET population. The thrombosis-predicting model specific for young patients with ET is useful for guiding therapeutic decisions.

OBJECTIVETo analyze the clinical features and pathogenetic gene mutation in a fetus at his third trimester with familial haemophagocytic lymphohistiocytosis (FHL).

METHODSTarget region sequencing and high-throughput sequencing were used to detect pathogenetic gene mutations for familial haemophagocytic lymphohistiocytosis in a late onset HLH fetus. Pathogenetic gene mutations of the patient and his parents were verified by Sanger dideoxy sequencing.

RESULTSA male neonate, who had right pleural effusion, hepatomegaly and splenomegaly previously revealed by fetus ultrasound, was delivered at full-term by cesarean section. His clinical presentation showed recurrent fever, tachypenea, decreased breath sounds on right side, hepatosplenomegaly etc., which were gradually aggravating Lab.tests results were as follows: WBC 9.88×10/L, Hb 91 g/L, Plt 13×10/L, ALT 18 U/L,AST 69 U/L,TBIL 207.2 µmol/L, DBIL 183.5 µmol/L, TG 3.05 mmol/L, Fib 0.88 g/L, Serum ferritin 3 120 ng/ml and sIL-2R 57 420 U/ml. FCM showed that CD3CD16CD56cells reached to 3.60% in the pripheral blood. Haemophagocytes were occasionally found in the bone marrow. NK/NKT stimulation test showed a severe damage of degranulation of NK cells. Sequence analysis of genomic DNA from his peripheral blood demonstrated the compound heterozygous mutations of UNC13D gene: c.2448-13 G>A in exon26 and c.1055+1 G>A in exon12, both were pathogenetic mutations. In detailed family survey, it was confirmed that the mutation c.2448-13 G>A in exon26 was inherited from his mother and c.1055+1 G>A in exon12 from his father.

CONCLUSIONA rare case of familial haemophagocytic lymphohistiocytosis type 3 (FHL3) with late fetus onset who carried pathogenetic compound heterozygous mutations of UNC13D gene. Those neonates with recurrent fever, serous effusions and multiple organ failure should be screened for FHL. Identifying the pathogenic gene mutations laid the foundation of conceiving disease-free newborns.