[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.

Type 1 interferon aggravates lipopolysaccharide-induced sepsis through upregulating Caspase-11 and Gasdermin D.

This study aimed to investigate the mechanism of type I interferon (IFN) in aggravating sepsis in bacterial infection, focusing on the roles of Caspase-11 (Casp11) and Gasdermin D (Gsdmd) in this process. Type I interferons, including IFNα and IFNß, were used to treat peritoneal macrophage harvested from wild-type or IFNα/ßR1 knockout (KO) mice, of which the levels of Casp11 and Gsdmd were monitored using real-time polymerase chain reaction (RT-PCR) and Western blot, the exposure to phosphatidylserine was monitored by flow cytometry, and tissue factor (TF) activation was assessed by RT-PCR and TF chromogenic assay. Endotoxemia in wild-type mice led to upregulation of Casp11 and Gsdmd in myeloid cells, which in contrast was attenuated in IFNα/ßR1 KO mice. IFNα or IFNß treatment led to dose-dependent upregulation of Casp11 and Gsdmd in peritoneal macrophages harvested from wild-type mice, but induced negligible changes in IFNα/ßR1 KO mice. Type I IFN promoted phosphatidylserine exposure in peritoneal macrophage from wild-type mice but not IFNα/ßR1 KO mice. Type I IFN induced insignificant changes of TF expression levels in both wild-type mice and IFNα/ßR1 KO mice, but the TF activity was markedly increased in wild-type mice after type I IFN treatment. Our data suggested that the upregulation of Casp11 and Gsdmd in myeloid cells and macrophages induced by endotoxemia was reliant on the expression of IFNα/ßR1. IFNα or IFNß treatment efficiently upregulated Casp11 and Gsdmd, phosphatidylserine exposure, and TF activity of macrophages. Therefore, type I IFN could aggravate sepsis through upregulating Casp11 and Gsdmd.

Benzophenanthridine alkaloids suppress lung adenocarcinoma by blocking TMEM16A Ca2+-activated Cl- channels.

An increasing amount of evidence suggests that transmembrane member 16A (TMEM16A)-encoded Ca2+-activated Cl- channels play a crucial role in regulating tumorigenesis. Therefore, specific and potent TMEM16A inhibitors have been proposed to potentially be useful for the treatment of cancer. During drug screening, we found that benzophenanthridine alkaloids (sanguinarine, sanguinarium chloride, sanguinarine nitrate, ethoxysanguinarine, chelerythrine, and dihydrosanguinarine) potently inhibited the recombinant TMEM16A current. The IC50 and Emax values for TMEM16A inhibition of six tested benzophenanthridine alkaloids were 5.6-12.3 µM and 77-91%, respectively. These benzophenanthridine alkaloids also significantly inhibited the endogenous TMEM16A currents and proliferation, migration, and induced apoptosis in LA795 lung adenocarcinoma cells. These data demonstrate that benzophenanthridine alkaloids are novel TMEM16A inhibitors and are potentially useful in specific cancer therapies. These findings also provide new insight for the development of TMEM16A inhibitors.

Rituximab for acute demyelinating myelopathy after allogeneic hematopoietic stem cell transplantation: a case report.

Acute demyelinating myelopathy after allogeneic hematopoietic stem cell transplantation (HSCT) is rare, and the exact pathogenesis remains unclear. Here, we report the case of a 20-year-old patient with B-cell acute lymphocyte leukemia (B-ALL) who developed acute demyelinating myelopathy approximately 10 months after HSCT. Magnetic resonance imaging revealed high T2 signal intensity lesions from the C2-T4 levels of the spinal cord. Treatments with high doses of corticosteroids, immunoglobulins, and rituximab improved his neurologic symptoms, and he achieved 44 months of leukemia-free and graft-versus-host disease (GVHD)-free survival, with no recurrence of the demyelination myelopathy. An understanding of the contribution of immune reconstitution to the pathogenesis of demyelinating myelopathy after HSCT and the association of this disease with GVHD will require more clinical cases.

[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.

CAR-T bridging to allo-HSCT as a treatment strategy for relapsed adult acute B-lymphoblastic leukemia: a case report.

BACKGROUND: Adults with relapsed acute lymphoblastic leukemia (ALL) have a poor prognosis, especially in patients who relapsed within 6 months of complete remission 1 (CR1). Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the treatment of choice. However, this can only be considered after complete remission 2 (CR2) is achieved. Therefore, bridging treatment is urgently needed. CASE PRESENTATION: In the present study, we report a relapsed adult B-cell ALL case that achieved CR2 after treatment with CD19-directed chimeric antigen receptor (CAR)-modified T cell (CAR-T) therapy. After subsequent allo-HSCT, the patient acquired 21 months of disease-free survival. CONCLUSION: The present results confirm that both CAR-T and allo-HSCT are effective for treating refractory or relapsed B-ALL. However, a novel sequential treatment strategy with these two therapeutic methods may achieve longer disease-free survival time.

[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.

T cell acute lymphoblastic lymphoma complicated with myeloid sarcoma in an adult: A case report.

The present case report describes a rare case of T cell acute lymphoblastic lymphoma (T-LBL) in the lymph node with myeloid sarcoma in the pericardium. A 33-year-old Chinese male was admitted to hospital on 4 July 2015 exhibiting a fever and having experienced wheezing and fatigue for the previous 7 days. Routine pathological, computed tomographic, cytological and immunophenotypic observations revealed a diagnosis of T-LBL in the lymph node on 7 August 2015, without evidence of bone marrow (BM) involvement. The patient received induction chemotherapy for T-LBL and achieved partial remission. The patient was identified to have multiple serous effusion and analysis of pericardial effusion cells revealed the diagnosis of T-LBL with extramedullary myeloid sarcoma (without BM involvement) on 25 November 2015. On 30 December 2015, the patient was identified to exhibit proliferation of primary myeloid cells in the peripheral blood and BM, and an abnormal karyotype in BM cells, indicating that the complicated myeloid sarcoma involved the BM. No matched donor was available so the patient received chemotherapy to manage the disease. The patient was discharged on 31 January 2016 and ceased treatment. The patient succumbed on 19 February 2016 at home. To the best of our knowledge, T-LBL complicated with myeloid sarcoma had not been previously reported in Chinese adult male patients. In addition, the involvement of the BM and aberrant karyotype of the complicated myeloid sarcoma in the patient were rare.

[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.

Increased TMEM16A Involved in Alveolar Fluid Clearance After Lipopolysaccharide Stimulation.

UNLABELLED: Transmembrane protein 16A (TMEM16A) regulates a wide variety of cellular activities, including epithelial fluid secretion and maintenance of ion homeostasis. Lipopolysaccharide (LPS), an outer membrane component of Gram-negative bacteria, is one of the major causes of acute lung injury (ALI). In this study, we investigated the effects of LPS on the expression of TMEM16A in LA795 cells and mouse lung tissue and the potential mechanism. RESULT: We detected the expression of TMEM16A in LA795 cells and mouse lung tissue by RT-PCR, Western blot, and RNA interference techniques. TMEM16A expression was significantly increased by LPS stimulation in LA795 cells and in mouse lung tissue. Moreover, the LPS-induced TMEM16A expression enhancement in lung tissue was much more prominent in the alveolar epithelial region than in bigger airway epithelial cells. The typical TMEM16A current was recorded, and LPS treatment significantly enhances the current amplitude in LA795 cells. TMEM16A shRNA or TMEM16A inhibitor (T16Ainh-A01) did not affect alveolar fluid clearance (AFC), while co-application of T16Ainh-A01 induced a stronger AFC inhibition than LPS alone. LPS notably and synchronously enhanced Akt phosphorylation (p-Akt) and TMEM16A expression in a time-dependent manner in LA795 cells. Taken together, our results suggest that TMEM16A maybe plays an important role in pathological conditions of LPS-induced ALI as a protective protein.

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.