[Clinical Efficacy of Hypomethylating Agent Therapy in Patients with Chronic Myelomonocytic Leukemia].

OBJECTIVE: To observe the clinical efficacy and safety of hypomethylating agent therapy in chronic myelomonocytic leukemia (CMML). METHODS: From February 2014 to June 2021, the clinical data, efficacy, survival time and safety of CMML patients diagnosed in the Second Hospital of Hebei Medical University and treated with hypomethylating agent therapy were retrospectively analyzed. RESULTS: A total of 25 CMML patients received hypomethylating agent therapy, including 18 cases treated with decitabine (DEC) and 7 cases treated with azacytidine (AZA) as the basic treatment. Among them, 20 patients responded, and 7 patients got complete remission (CR). All patients with CR were treated with DEC as the basic treatment. Five cases of CR occurred in the first 4 courses of treatment. After a median follow-up of 16.4 (9.4-20.5) months, 4 patients with CR progressed to acute myeloid leukemia (AML). The median overall survival (OS) time of 25 CMML patients was 17.4 months (95%CI: 12.437-22.363). According to MD Anderson prognostic scoring system (MDAPS), CMML-specific prognostic scoring system (CPSS), CPSS molecular (CPSS-mol), Mayo molecular model (MMM), risk stratification of patients was performed, and the difference only between different risk stratification of MDAPS and survival time was statistically significant. Common adverse reactions of hypomethylating agent therapy in CMML patients included infection, gastrointestinal reaction, hematological toxicity, skin allergy and liver function damage. All patients' symptoms were improved after corresponding treatment. CONCLUSION: Hypomethylating agent therapy is effective and safe for CMML patients. CR mostly occurs in the first 4 courses of treatment, and hypomethylating agent therapy combined with low-dose chemotherapy can be used for patients who do not respond. Hypomethylating agent therapy can delay the disease, but can't prevent progression.

[Analysis of Relapse after Allogeneic Hematopoietic Stem Cell Transplantation in Patients with Hematological Malignancies: A Single-center Study].

OBJECTIVE: To analyze the survival, prognostic factors, and prevention of relapse after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in patients with hematological malignancies, and explore the relationship between immune reconstruction, loss of human leukocyte antigen (HLA-loss) and relapse after transplantation. METHODS: From July 2012 to June 2020, 47 patients with hematological malignancies who relapsed after allo-HSCT were retrospectively analyzed, including 20 cases undergoing matched-sibling donor transplantation (MSD), 26 cases undergoing haploidentical transplantation (HID), and 1 case undergoing matched-unrelated donor transplantation (MUD). Multivariate analysis was used to analyze the risk factors related to post-relapse overall survival (PROS). RESULTS: All the 47 patients were implanted successfully. The cumulative incidence of grade Ⅱ-Ⅳ, Ⅲ/Ⅳ acute graft-versus-host disease (aGVHD) and chronic GVHD (cGVHD) was 40.4%, 10.6%, and 31.9%, respectively. The incidence of grade Ⅱ-Ⅳ and Ⅲ/Ⅳ aGVHD in HID group was 42.3% and 11.5%, while in MD group was 38.1% and 9.5% (P=0.579, P=1.000), and the incidence of cGVHD in the two groups was 34.6% and 28.6% (P=0.659). The PROS of patients with NK cell absolute count > 190 cells/µl 30 days after transplantation was higher than that of patients with NK cell absolute count ≤190 cells/µl (P=0.021). The 1-year and 3-year PROS of all the patients was 68.1% and 28.4%, respectively, while in the HID group was 78.9% and 40.3%, in the MD group was 54.4% and 14% (P=0.048). Multivariate analysis showed that grade Ⅱ-Ⅳ aGVHD and time of relapse < 3 months were independent risk factors of PROS (P<0.05). CONCLUSION: The therapeutic effect of haploidentical transplantation in patients with relapsed hematological malignancies after allo-HSCT is better than that of matched donor transplantation. The high absolute count of NK cells 30 days after transplantation can increase PROS. Grade Ⅱ-Ⅳ aGVHD and time of relapse < 3 months have prognostic significance for long-term survival of patients with relapsed hematological malignancies after transplantation.

Programmed cell death protein-1 inhibitor combined with chimeric antigen receptor T cells in the treatment of relapsed refractory non-Hodgkin lymphoma: A case report.

BACKGROUND: Chimeric antigen receptor T cell (CART) therapy has benefited many refractory lymphoma patients, but some patients experience poor effects. Previous studies have shown that programmed cell death protein-1 (PD-1) inhibitors can improve and prolong the therapeutic effect of CAR-T cell treatment. CASE SUMMARY: A 61-year-old male presented with 15-d history of diarrhea and lower-limb edema. A large mass was detected in the pelvis, and pathology indicated non-Hodgkin diffuse large B-cell lymphoma. After three cycles of the R-CHOP chemotherapeutic regimen, the patient showed three subcutaneous nodules under the left armpit and both sides of the cervical spine. Pathological examination of the nodules indicated DLBCL again. The patient was diagnosed with relapsed and refractory diffuse large B-cell lymphoma. We recommended CAR-T cell treatment. Before treatment, the patient's T cell function and expression of immune detection points were tested. Expression of PD-1 was obviously increased (52.7%) on cluster of differentiation (CD)3+ T cells. The PD-1 inhibitor (3 mg/kg) was infused prior to lymphodepleting chemotherapy with fludarabine and cyclophosphamide. CAR-CD19 T cells of 3 × 106/kg and CAR-CD22 T cells 1 × 106/kg were infused, respectively. The therapeutic effect was significant, and the deoxyribonucleic acid copy numbers of CAR-CD19 T cells and CAR-CD22 T cells were stable. Presently, the patient has been disease-free for more than 12 mo. CONCLUSION: This case suggests that the combination of PD-1 inhibitors and CAR-T cells improved therapeutic efficacy in B-cell lymphoma.

[Analysis of Clinical Features and Prognosis of Patients with Chronic Neutrophil Leukemia].

OBJECTIVE: To provide clinical basis for the diagnosis and treatment of chronic neutrophilic leukemia (CNL) and to provide possible molecular targets for the treatment. METHODS: By summarizing the clinical data of 14 patients with CNL, the clinical characteristics, gene mutation types and possible prognostic factors were analyzed. RESULTS: Among the 14 patients with CNL, males (9 cases) were more than females (5 cases), with a median age of 57 years old. The detection rate of CSF3R mutation was 92.86% (13/14), including 12 cases (85.71%) with T318I mutation and 1 case of Y799X mutation, and only 1 case was not detected for mutation of CSF3R. The ASXL1 mutation was detected in 42.86% (6/14) of the patients, all of which were nonsense mutations, including 4 cases with R693X and 2 cases with E705X, and 14.29% (2/14) of the patients was detected for SETBP1 mutation, all of which were with D868N mutation. No patients with simultaneous ASXL1 and SETBP1 mutations were found, and JAK2 and CALR mutations were not detected. All of the patients had normal karyotypes. These patients' median survival time was 30 months (95%CI 13.19-46.80), and the influence of age over 60 years old was statistically significant (21.83 months vs 35.35 months) (P＜0.05). CONCLUSION: It is difficult to diagnose CNL. CSF3R T618I mutation is its specific mutation, and ASXL1 mutation and SETBP1 mutation have auxiliary diagnostic significance for CNL. The age＞60 years old at diagnosis is a factor of unfavourable prognosis.

Relative hematopoietic stem cell transplantation for the treatment of blastic plasmacytoid dendritic cell neoplasm: a case report and literature review.

OBJECTIVE: To report the long-term survival of a patient with maternal plasmacytoid dendritic cell tumor (BPDCN) treated by allo-HSCT. METHODS: The patient was diagnosed by skin infiltration, bone marrow involvement, skin biopsy and bone marrow cytology. CD4, CD56, and CR123 were expressed in tumor cells. The first complete remission (CR1) was achieved by CHOP-E and MA regimens before transplantation. In March 2018, HLA 5/10 matched hematopoietic stem cell transplantations were performed in the paternal donors and fathers. The pretreatment regimen was FTBI (4 Gy × 2, total lung dose 6 Gy) + CY (cyclophosphamide 1.8 g/m2 × 2 d) + Flu (30 mg/m2 × 4 d) + ATG (10 mg/kg); CSA + MMF + MTX to prevent GVHD. MNC 6.45 × 108/kg and CD34 + cells 7.40 × 106/kg were transfused back. + Granulocyte and platelet were engrafted 12 days and 14 days respectively. The donor-recipient chimerism was monitored regularly, immunosuppressive agents were regulated, and minimal residual disease (MRD) was monitored by flow cytometry. No DLI. RESULTS: Complete donor implantation and continuous remission were achieved after transplantation. After transplantation, complications such as mucositis, viral infection, hypoproteinemia, and renal dysfunction occurred. At present, the disease-free survival is 10 months. CONCLUSION: BPDCN combined with TBI in the CR1 phase can effectively control the disease; HLA haploidentical hematopoietic stem cell transplantation is also an alternative treatment, and complications should be treated in a timely manner.

[Analysis of Phenotype and L12R Mutation in Signal Peptide and 3' Non-translation Region c11814-insAA Mutation of F7 Gene in a Family with Hereditary Coagulation Factor VII Deficiency].

OBJECTIVE: To examine one young female patient with hereditary FVII deficiency and her family members, to observe the gene mutation and clinical phenotype, and to investigate the molecular mechanism of the dysfunction. METHODS: Prothrombin time (PT), activated partial thromoploastin time (APTT), fibrinogen (Fg) and FVII activity (FVII:C) and FVII antigen (FVII:Ag) were tested. The gene mutations were sought by DNA sequencing for all of the exons and flanks, 5' and 3' non-translation region of F7 gene. To confirm the role of the found gene mutation, the reverse sequence were determined with Chromas software. To infer the influence of the mutation on the synthesis and function of FVII protein, the FVII protein molecule model containing the found mutation was constructed and the function prediction was performed by the signal peptide prediction database. RESULTS: Compared with the normal population, the proband's PT value was significantly prolonged, and the ratio % FVII:C and that of FVII:Ag were significantly decreased by 1.1% and 0.9%, respectively. The PT, APTT, FVII:C and FVII:Ag of the proband's parents were both normal. Heterozygous 556th nucleotide mutations T/G were found in the proband's and his father's exon lA of F7 gene, with codon CTG turning into CGG, corresponding leucine (L) into arginine (R), i.e Leu12Arg. Function prediction showed that L12R mutations affected the segmentation of different parts of the signal peptide and its corresponding function, which could result in the decline in the mature protein synthesis and its activity obviously. In addition, a spontaneous 3' untranslated region c11814-insAA heterozygous mutation was detected in the proband's F7 gene, while her parents didn't possess this mutation. CONCLUSION: A new hererozygous mutation (L12R) located in signal peptide of F7 gene is the primary molecular basis of the case with hereditary FVII deficiency. At the same time, the proband's spontaneous 3' non-translation region c11814-insAA mutation may lead to the further reduetion of the FVII synthesis.

IL-11 promotes the treatment efficacy of hematopoietic stem cell transplant therapy in aplastic anemia model mice through a NF-κB/microRNA-204/thrombopoietin regulatory axis.

Hematopoietic stem cell (HSC) transplantation could be of therapeutic value for aplastic anemia (AA) patients, and immunosuppressants may facilitate the efficiency of the procedure. As anti-inflammatory cytokine interleukin-11 (IL-11) has a thrombopoietic effect, its use in cases of chronic bone marrow failure, such as AA, has been proposed to induce HSC function. However, the putative mechanisms that may support this process remain poorly defined. We found that decreased miR-204-5p levels were coincident with increased proliferation in mouse HSCs following exposure to IL-11 in vitro. Through inhibiting NF-кB activity, miR-204-5p repression was demonstrated to be a downstream effect of IL-11 signaling. miR-204-5p was shown to directly target thrombopoietin (TPO) via sequence-dependent 3'-UTR repression, indicating that this microRNA-dependent pathway could serve an essential role in supporting IL-11 functions in HSCs. Increased TPO expression in HSCs following IL-11 exposure could be mimicked or blocked by inhibiting or overexpressing miR-204-5p, respectively. Consistent with these in vitro findings, IL-11 promoted HSC engraftment in a mouse model of AA, an effect that was attenuated in cells overexpressing miR-204-5p. The reduction in miR-204-5p levels is an integral component of IL-11 signaling that may play an essential role in treating AA.

[Effect of Artesunate on Proliferation, Cell Cycle and Apoptosis of SKM-1 Cells and Its Underlying Mechanisms].

OBJECTIVE: To investigate the effects of artesunate (ART) on proliferation, cell cycle and apoptosis of SKM-1 cells in vitro and to explore the underlying mechanisms. METHODS: After SKM-1 cells were treated with different concentrations of ART, the cell proliferation was determined by CCK-8 method. Apoptosis and distribution of cell cycle were detected by flow cytometry. Both DCFH-DA fluorescent probe and Fluo-3-Am fluorescent probe were used to detect the changes of intracellular reactive oxygen species (ROS) and calcium ion concentration. Western blot was used to measure the protein levels of BCL-2, BAX, BAD, P-BAD, survivin and XIAP. RESULTS: ART obviously inhibited the growth of SKM-1 cells in time and dose-dependent manners (r = -0.841; r = 0.-786). The antioxidant trolox-pretreatment significantly decreased the growth inhibition effect of ART on SKM-1 cells. Caspase inhibitor Ac-DEVD-CHO partially reduced the growth inhibition effect of ART on SKM-1 cells. After treatment with ART for 24 hours, the apoptosis of SKM-1 cells was found, the cell cycle of SKM-1 was arrested in G0/G1 phase, ART could elevate the levels of calciumion and reactive orygen. ART could significantly down-regulate the protein expression levels of P-BAD and survivin in SKM-1 cells, and showed a highly negative correlation with ART dose (r = -0.909; r = -0.849). On the contrary, ART had no significant effect on expression levels of BAD and XIAP in SKM-1 cells, and after ART treatment, although BCL-2 protein expression was not significantly different when compared with control group, but the BCL-2/BAX ratio significantly decreased and highly negatively correlated with ART dose (r = -0.866). CONCLUSION: The ART significantly suppresses the cell proliferation, induces the apoptosis and promoted cell cycle arrest at G0/G1 phase in SKM-1 cells. The mechanisms of ART anti-MDS is associated with the increase of intracellular calciumion concentration and ROS levels. In addition, the pro-apoptotic activity of ART may be involved in the regulation of BCL-2 /BAX ratio and the expressions of P-bad and survivin.

Magnetic Nanoparticles of Fe3O4 Enhance Artesunate-inducing Apoptosis of SKM-1 Cells.

OBJECTIVE: To investigate the inhibitory effect of the copolymer of magnetic nanoparticles of Fe(3)O(4) (MNPs-Fe(3)O(4)) and artesunate (ART) on myelodysplastic syndromes (MDS) cell line SKM-1 cells and the potential mechanisms. METHODS: The protein expression levels of BCL-2, BAX, Caspase-3, and Survivin in SKM-1 cells treated with or without the co-polymer were measured by Western blot. The co-polymer-induced apoptosis rate of SKM-1 cells was measured by flow cytometry. RESULTS: The apoptosis rate of SKM-1 cells in the copolymer groups was higher than that in both MNPs-Fe(3)O(4) and artesunate groups alone. The MNPs-Fe(3)O(4) may enhance ART-induced cell apoptosis. Western blot assay showed that the expression of survivin and BCL-2 protein were down-regulated in the ART group, and this down-regulation was even more significant in the group of copolymer of ART with MNPs-Fe(3)O(4). The levels of BAX were increased both in ART group and the copolymer of ART with MNPs-Fe(3)O(4) group, as compared with control group and MNPs-Fe(3)O(4) group. The levels of active-caspase-3 were obviously up-regulated when the ART was combined with the MNPs-Fe(3)O(4). The copolymer of ART with MNPs-Fe(3)O(4) could trigger changes in the expression levels of apoptosis-related genes in SKM-1 cells, among which up-regulation of BAX and down-regulation of survivin and BCL-2 are the 2 major alterations. CONCLUSION: Artesunate can induce the apoptosis of SKM-1 cells, and MNPs-Fe(3)O(4) may enhance the cell apoptosis induced by ART.

[BMMSC from blastic phase CML down-regulate leukemia cell apoptosis].

The purpose of this study was to investigate the effect of bone marrow mesenchymal stem cells (BMMSC) from patients with chronic myeloid leukemia (CML) in blastic phase (Bp) on K562 cells and the primary CML-Bp cells, and to explore its potential mechanisms. K562 cells and primary CML-Bp cells were co-cultured with BMMSC of different groups; the cell proliferation was detected by MTT method, the cell apoptosis rate and mitochondrial membrane potential were measured by flow cytometry, the expression levels of Caspase-8, Caspase-9, and activated Caspase-3 in cells were measured by Western blot. The results showed that the CML-Bp BMMSC could enhance the survival rate of K562 cells treated with adviamycin (ADM) and display protective effect on K562 cells and primary CML-Bp mononuctear cells, inhibited ADM-induced leukimia cell apoptosis (P < 0.05); as compared with CML-chronic phase (CML-Cp) BMMSC and normal BMMSC, the CML-Bp BMMSC showed the highest protective effect on leukemic cells, the mitochondrial membrane potential of co-cultured cells slightly droped (P < 0.05). In the CML-Bp BMMSC cultured with K562 cells, the expression level of caspase-3 was more down-regulated than that in K562 alone plus ADM group, while the expression of caspase-9 significantly increased (P < 0.05). It is concluded that the CML-Bp BMMSC down-regulates ADM-induced leukemia cell appoptosis, its mechanism may relate with the inhibition of mitochondrial membrane potential drop, the stabilization of unactive expression of caspase-9 and down-regulation of caspase-3 expression.

[Effects of DNA methylation on expression of TIG1 gene in acute leukemia].

This study was purposed to investigate the expression and methylation status of TIG1 in acute leukemia (AL). The TIG1 expression of 53 cases of AL and 20 cases of normal control (NC) were measured by using real-time quantitative PCR (RT-QT-PCR) and methylation-specific PCR(MS-PCR). The leukemia KG-1a, U937 and K562 cells were treated with 5-Aza-CdR. The results indicated that TIG1 gene expressed at a high level in cases of NC, but expressed at a low level in patients with AL. TIG1 gene was unmethylated in NC, but frequently methylated in AL. Aberrant methylation rate of TIG1 in AL was 75% (40/53). The expression of TIG1 in unmethylated patients was higher than that in methylated patients. Hypermethylation of TIG1 promoter CpG islands was detected in all the cell lines. 5-Aza-CdR treatment led to the hypomethylation of TIG1 promoter CpG islands. After the treatment with 5-Aza-CdR of different concentration, the expression of TIG1 was restored, and the effect of 5-Aza-CdR displayed dose-dependency. It is concluded that the reduced expression of TIG1 may play an important role in the pathogenesis of AL, and methylation may be responsible for the decreased transcription of TIG1 gene.

[Clinical analysis of 14 patients with thrombotic thrombocytopenic purpura].

In order to enhance the understanding of thrombotic thrombocytopenic purpura (TTP), the clinical features, laboratory characteristics, treatment and outcome of 14 patients with TTP were retrospectively analyzed and investigated. The results showed that 7 out of 14 patients with TTP had predisposing factors, such as pregnancy in 4 cases, infection in 3 cases, systemic lupus erythematosus (SLE) in 1 case and hematopoietic stem cell transplantation (HSCT) in 1 case. Fourteen patients all had neuropsychological symptoms, hemolytic anemia with negative-Coombs test, and decreased platelet counts. Eight patients had irregular fever with different degree. There were 8 patients with kidney damage including proteinuria in 8 cases and renal function abnormalities in 4 cases. The von Willebrand factor-cleaving protease (VWF-CP, ADAMTS13) activity of 13 cases out of 14 patients significantly decreased (less than 10%). At same time, plasma ADAMTS13 inhibitors were detected in 12 cases out of these 13 patients with decreased ADAMTS13 activity. After treatment with plasma exchange, glucocorticoid and rituximab so on, 12 cases achieved complete remission, in which 8 cases relapsed in two years. Two patients died at last, in which one case was secondary to HSCT. It is concluded that TTP is a kind of thrombotic microangiopathy due to platelet microthrombosis involved in multiple systems and multiple organs dysfunction with dangerous clinical process. The mortality of TTP patients is very high. Early diagnosis and early treatment with plasma exchange as the main means can greatly improve the prognosis of patients with TTP.

[Construct Mxi1 mutation gene expression vector from leukemia cell line KG1].

OBJECTIVE: To construct the eukaryotic expression vector for Max interacting protein 1 (Mxi1). METHODS: The full length cDNA of Mxi1 gene obtained from fetal lymphocyte and KG1 cells were inserted into plasmid pDs-red2-N1 respectively to generate pDs-red2-N1/Mri1 (wild/mutation type). Then the recombinant vector was transfected into Cos-7 cells via liposome. 48 hours post transfection, mRNA of Mri1 gene was detected by RT-PCR and Mxi1 protein expression was detected by flow cytometry and fluorescence microscope in the Cos-7 cells. RESULTS: The eukaryotic expression vector of Mxi1 was constructed and transfected into eukaryotic cells successfully. The expression of red fluorescence protein in the transfected Cos-7 cells was observed under fluorescence microscope which implied the expression of Mxi1. The transfect efficiency of both wild and mutation type were in a high level in 3 days after transfected, which lasted to 6 d. RT-PCR amplified the total RNA extracted from the transfected Cos-7 cells could find increased mRNA level of Mxi1 gene. CONCLUSION: We successfully constructed the eukaryote expression vector for Mri1 gene; Cos-7 cells transfected with the vector via liposome could express Mxi1 protein. These could be useful for the further study of the Myc gene modulation.

[Fechtner syndrome, a nonmuscle myosin heavy chain 9 gene mutation related disease: a case report and literature review].

OBJECTIVE: To improve the recognition of Fechtner syndrome. METHODS: The clinical and laboratory data and family survey of a patient with Fechtner's syndrom was reported. RESULTS AND CONCLUSION: Giant platelets, thrombocytopenia and characteristic granulocyte inclusion bodies (Döhle-like bodies) were found in both peripheral blood and bone marrow smears of the patient. Clinically the patient had renal damage, nervous deafness, and vitreous lesions. There was a family genetic tendency on family survey the diagnosis of Fechtner syndrome is established.

[Effects of wild type PTEN gene on proliferation, apoptosis and the influence on apoptosis key factor Bcl-2 and Caspase family on K562 cells].

OBJECTIVE: To investigate the effect of tumor-suppressing gene,wild type PTEN gene, mediated by adenovirus vector on the cell proliferation, apoptosis and the influence on apoptosis key factor Bcl-2 and Caspase family on human chronic myeloid leukemia (CML) cell line K562 in vitro. METHODS: The recombinated Ad-PTEN gene containing green fluorescent protein gene (Ad-PTEN-GFP) or the empty vector (Ad-GFP) was transfected into K562 cells. The growth of K562 cells was evaluated by MTT assay; the transfection efficiency of Ad-PTEN-GFP, apoptosis rate and proliferation index (PI) were assessed by flow cytometry (FCM). Morphological characteristics of transfected cells under light and transmission electron microscope were applied to demonstrated the apoptosis; DNA ladder and fluorescent staining were also tested; the PTEN, Bcl-2 mRNA levels were detected by real-time fluorescent relative-quantification reverse transcriptional PCR (FQ-PCR); PTEN and Bcl-2 protein levels were detected by Western Blotting; and Caspase-3/7 and -9 protein activity were detected by corresponding kits. RESULTS: The 200 multiplicity of infection (MOI) of Ad-PTEN-GFP was applied to transfect K562 cells. The maximum growth inhibiting ratio was 37.1%. The early and advanced apoptosis rates were higher than Ad-GFP group and untransfected group (P<0.05). After 3 days transfaction of PTEN gene the Bcl-2 mRNA and protein were 0.27 fold and 0.58 fold respectively; and the Caspase-3/7 and -9 protein activity increased in time-depentend manner after transfected with PTEN gene at the first 3 days compared with Ad-GFP group and untransfected group. CONCLUSION: Over expression of PTEN gene can inhibit K562 cells proliferation and promote cell apoptosis probability via inhibiting Bcl-2 expression and up-regulating the Caspase-3/7 and -9 ability.

Expression and mutation analysis of genes that encode the Myc antagonists Mad1, Mxi1 and Rox in acute leukaemia.

The Myc antagonists Mad1, Mxi1 and Rox proteins share two highly conserved domains, Sin3-interacting domain (SID) and basic helix-loop-helix leucine zipper domain (bHLHzip), which are essential for these proteins to function during molecular switching from proliferation to differentiation. In an attempt to identify mutations in Mad1, Mxi1 and Rox genes in human haematological malignancies, we screened 10 haematopoietic cell lines, bone marrow mononuclear cells (BMMNC) from 26 patients with haematological malignancies and peripheral blood mononuclear cells (PBMNC) from 30 healthy volunteers, using reverse transcription-polymerase chain reaction, single strand conformation polymorphism analysis and sequencing. Mad1, Mxi1 and Rox genes were expressed in all samples. Four polymorphisms were found in cell lines BMMNC and PBMNC: two in Mad1, one in Mxi1 and one in Rox. Nine missense mutations were detected: two in Mad1 in patients, four in Mxi1 (three in patients and one in KG-1 cell line), and three in Rox in patients. No mutations were detected in PBMNC from healthy volunteers. Among six patients with acute lymphoblastic leukaemia, two had Mxi1 mutations and another two had Rox mutations. These mutations were associated with poorer clinical outcomes. This is the first report to show that Mad1, Mxi1 and Rox genes were expressed and displayed mutations in haematological malignancies.

[Expression and mutation of myc antagonist genes Mad1, Mxi1 and Rox in leukemia cells].

OBJECTIVE: To investigate the expression and mutation of Mad1, Mxi1 and Rox genes in leukemia cells. METHODS: Expression and mutation of Mad1, Mxi1 and Rox genes in bone marrow mononuclear cells (BMMNC) from 26 de novo acute leukemia (AL) patients, and in peripheral blood mononuclear cells (PBMNC) from 30 healthy volunteers, as well as in 7 human leukemic cell lines were analyzed by reverse transcription-polymerase chain reaction (RT-PCR), single strand conformational polymorphism (SSCP) and DNA sequencing. RESULTS: RT-PCR showed that all the above cells expressed Mad1, Mxi1 and Rox mRNA. SSCP revealed four polymorphisms: two in Mad1, one each in Mxi1 and Rox. DNA sequencing detected nine missense mutations: two in Mad1 in AL patients, four in Mxi1 (three in AL patients and one in KG-1 cell line), and three in Rox in AL patients. The mutations of Mad1, Mxi1 and Rox mRNA were detected in 2, 3 and 3 patients, respectively. CONCLUSION: It is for the first time to demonstrate the mutations of Mad1, Mxi1 and Rox genes in AL patients suggesting these mutated genes involve in the pathogenesis of leukemia.

[Effects of integrin beta1 on phycocyanin inhibiting proliferation of K562 cells].

This study was purposed to investigate the effect of phycocyanin at different concentration on proliferation of K562 cells, to detect the changes of integrin beta1 expression and intracellular focal adhesion kinase (FAK) gene expression on the surface K562 cells treated with phycocyanin, and to explore the possible mechanism of integrin beta1 effect on phycocyanin inhibiting proliferation of K562 cells. The expression level of integrin beta1 on the surface of K562 cells was evaluated by flow cytometry (FCM); the growth of K562 cells treated with phycocyanin was measured by MTT assay; the expression level of FAK mRNA was analyzed by relatively quantitative RT-PCR after four-day culture of K562 cells with phycocyanin of 40 microg/ml, 80 microg/ml and 160 microg/ml, respectively. The results showed that integrin beta1 expression on the surface of K562 cells was significantly higher than that in bone marrow mononuclear cells (BMMNC) from normal subjects. Phycocyanin could not change the level of integrin beta1 expression. Phycocyanin could increase the expression of FAK gene on K562 cells and inhibit the proliferation of K562 cells. It is concluded that phycocyanin can inhibit the proliferation of K562 cells through enhancing the conjunction of cell stroma with integrin beta1 on K562 cell surface, up-regulating the expression level of FAK gene in K562 cells, restoring the signaling pathway of proliferation inhibition mediated by integrin beta1. The possible mechanism of phycocyanin in the proliferation inhibition of K562 cells is to increase the expression of FAK gene. The phycocyanin may be considered as a potential agent for inhibition of cancer cell proliferation.

WT1 gene expression lowered by IL-12 In vitro in peripheral blood mononuclear cells from patients with leukemia or myelodysplastic syndromes.

Previous studies demonstrated that interleukin-12 (IL-12) enhances the non-MHC-restricted cytotoxic activity of NK cells and facilitate specific allogeneic human cytotoxic T lymphocyte responses against fresh leukemia cells and cell lines. The Wilms' tumor gene, WT1 mRNA, has been used as a marker of minimal residual disease (MRD) for evaluating therapeutic efficacy of patients with leukemia or myelodysplastic syndrome (MDS). This study was aimed to investigate whether in vitro IL-12 can lower WT1 gene expression in peripheral blood monuclear cells (PBMNC) from patients with leukemia or MDS. PBMNC from these 30 patients and 5 healthy volunteers were cultured at 5 x 10(5) cells/ml alone with or without 100 units/ml of IL-12 for 3 days. WT1 mRNA was measured by competitive reverse transcription polymerase chain reaction (RT-PCR) since WT1 mRNA is considered as a marker of minimal residual disease (MRD) in leukemia and MDS. The results demonstrated that WT1 mRNA in PBMNC of 5 healthy volunteers was less than 10(3) copies/microg of total RNA. Following the 3-day IL-12 treatment, mean WT1 mRNA of PBMNC was reduced from 10(4.8) to 10(4.2) copies/microg of total RNA in 6 CML patients, from 10(5.4) to 10(4.8) copies/microg in 12 MDS patients and from 10(5.0) to 10(4.2) copies/microg in 5 AML patients in CR, but not reduced in 5 of 7 AML in non-CR. It is concluded that IL-12 significantly decrease the quantity of leukemia cells in PBMNC of most patients with MDS, CML and AML in CR. IL-12 may be of considerable benefit in the elimination of MRD in patients with hematological malignancies.