Disruption of mitochondrial oxidative phosphorylation by chidamide eradicates leukemic cells in AML.

PURPOSE: Nowadays, the oxidative phosphorylation (OXPHOS) correlated with leukemogenesis and treatment response is extensive. Thus, exploration of novel approaches in disrupting OXPHOS in AML is urgently needed. MATERIALS AND METHODS: Bioinformatical analysis of TCGA AML dataset was performed to identify the molecular signaling of OXPHOS. The OXPHOS level was measured through a Seahorse XFe96 cell metabolic analyzer. Flow cytometry was applied to measure mitochondrial status. Real-time qPCR and western blot were used to analyze the expression of mitochondrial or inflammatory factors. MLL-AF9-induced leukemic mice were conducted to measure the anti-leukemia effect of chidamide. RESULTS: Here, we reported that AML patients with high OXPHOS level were in a poor prognosis, which was associated with high expression of HDAC1/3 (TCGA). Inhibition of HDAC1/3 by chidamide inhibited cell proliferation and induced apoptotic cell death in AML cells. Intriguingly, chidamide could disrupt mitochondrial OXPHOS as assessed by inducing mitochondrial superoxide and reducing oxygen consumption rate, as well as decreasing mitochondrial ATP production. We also observed that chidamide augmented HK1 expression, while glycolysis inhibitor 2-DG could reduce the elevation of HK1 and improve the sensitivity of AML cells exposed to chidamide. Furthermore, HDAC3 was correlated with hyperinflammatory status, while chidamide could downregulate the inflammatory signaling in AML. Notably, chidamide eradicated leukemic cells in vivo and prolonged the survival time of MLL-AF9-induced AML mice. CONCLUSION: Chidamide disrupted mitochondrial OXPHOS, promoted cell apoptosis and reduced inflammation in AML cells. These findings exhibited a novel mechanism that targeting OXPHOS would be a novel strategy for AML treatment.

Mutant C/EBPα p30 alleviates immunosuppression of CD8+ T cells by inhibiting autophagy-associated secretion of IL-1ß in AML.

OBJECTIVES: Mutant C/EBPα p30 (mp30), the product of C/EBPα double mutations (DM), lacks transactivation domain 1 and has C-terminal loss-of-function mutation. Acute myeloid leukaemia (AML) patients harbouring C/EBPα DM could be classified as a distinct subgroup with favourable prognosis. However, the underlying mechanism remains elusive. MATERIALS AND METHODS: Autophagy regulated by mp30 was detected by western blot and immunofluorescence. Immune infiltration analysis and GSEA were performed to investigate autophagic and inflammatory status of AML patients from the GSE14468 cohort. Flow cytometry was applied to analyse T cell activation. RESULTS: Mp30 inhibited autophagy by suppressing nucleus translocation of NF-κB. Autophagy-associated secretion of IL-1ß was decreased in mp30-overexpressed AML cells. Bioinformatic analysis revealed that inflammatory status was attenuated, while CD8+ T cell infiltration was upregulated in C/EBPα DM AML patients. Consistently, the proportion of CD8+ CD69+ T cells in peripheral blood mononuclear cells (PBMCs) was upregulated after co-culture with mp30 AML cell conditional culture medium. Knock-out of IL-1ß in AML cells also enhanced CD8+ T cell activation. Accordingly, IL-1ß expression was significantly reduced in the bone marrow (BM) cells of C/EBPα DM AML patients compared to the wildtype, while the CD8+ CD69+ T cell proportion was specifically elevated. CONCLUSIONS: C/EBPα DM alleviates immunosuppression of CD8+ T cells by inhibiting the autophagy-associated secretion of IL-1ß, which elucidated that repression of autophagy-related inflammatory response in AML patients might achieve a favourable clinical benefit.

[Clinical Effect of Tyrosine Kinase Inhibitors in the Treatment of P230 Chronic Myeloid Leukemia].

OBJECTIVE: To observe the curative efficacy of tyrosine kinase inhibitors (TKIs) in the treatment of e19a2 transcript (P230) CML chronic phase (CML-CP) patients. METHODS: The clinical data of 11 P230 CML-CP patients were collected from July 2008 to December 2019. Blood routine examination, bone marrow cytology, chromosome, and BCR-ABL qualitative and quantitative tests were performed at initial diagnosis. After TKIs treatment, BCR-ABL (P230)/ABL in peripheral blood was regularly detected to evaluate molecular response by real-time quantitative PCR. RESULTS: There were 11 patients (7 males and 4 females) in chronic phase from 6 domestic hospitals enrolled, their median age was 46 years old (range from 19 to 56 years old). Among 4 patients treated with imatinib (400 mg, qd) firstly, 3 cases switched to nilotinib (400 mg, bid) and 1 case switched to dasatinib (100 mg, qd) due to failure to achieve best molecular response at the landmark time or mutation of ABL kinase. Then major molecular response (MMR) was obtained within 1 year. In addition, 5 patients were treated with nilotinib (300 mg, bid) and 2 patients with dasatinib (100 mg, qd) as first-line treatment, all of them got MMR within 6 months. CONCLUSION: For intolerance or resistance to imatinib, second-generation TKIs can enable P230 CML patients to achieve deeper molecular response, and MMR in a short time.

[The Establishment and Identification of Acute Myeloid Leukemia NOD-SCID-IL2rg-/-Mice Model by Using Luciferase-Expressing KG1a Cells].

OBJECTIVE: To establish the in vivo traceable acute myeloid leukemia mice model with Luciferase-Expressing KG1a Cells. METHODS: KG1a cells with stable luciferase gene expression (called as KG1a-Luc cells) were constructed by lentivirus transfection, then sifted out by puromycin. Eighteen male NOD-SCID-IL2rg-/-mice aged 8 to 12 weeks were randomly and equally divided into two groups: the control group and the KG1a-Luc group. The mice in KG1a-Luc group were injected with 200 µl PBS containing 5×106 KG1a-Luc cells through tail veins, and the mice in control group were injected with 200 µl PBS only. The bioluminescence imaging technology was used to monitor the tumor burden in vivo. The peripheral blood of the mice in both groups was analyzed by flow cytometry. After the mice were sacrificed, there were pathologic evaluations: bone marrow and spleens made into smears, and livers sliced to get paraffin sections. The survival time of the mice in the two groups was recorded and compared. RESULTS: KG1a cells expressing luciferase stably were successfully obtained. The tumor luminescence wildly spread at day 17 captured by in vivo imaging. The KG1a-Luc tumor cells could be detected in the peripheral blood of the mice, with the average percentage of (16.27±6.66)%. The morphology and pathology result showed that KG1a-Luc cells infiltrate was detected in bone marrow, spleens and livers. The survival time of the KG1a-Luc mice was notably shorter as compared with those in the control group, the median survival time was 30.5 days (95%CI: 0.008-0.260). CONCLUSION: The acute myeloid leukemia NOD-SCID-IL2rg-/-mouse model was successfully established by tail vein injection of 5×106 KG1a-Luc cells.

[Expression and Significance of BTLA and Its Ligand HVEM in Patients with Chronic Myelomonocytic Leukemia].

OBJECTIVE: To investigate the expression and significance of B and T lymphocyte weakening factor (BTLA) in patients with chronic myelomonocytic leukemia (CMML). METHODS: Real-time PCR was used to detect the expression of BTLA and its ligand HVEM mRNA in 11 patients with chronic myelomonocytic leukemia and 11 normal donors. Flow cytometry was used to detect expression of BTLA and its HVEM on the cell surface of peripheral blood T lymphocytes and γδ T cells. RESULTS: The median values of BTLA and its ligand HVEM mRNA expression in peripheral blood of patients with CMML were 0.009% and 559.4%, respectively, which were significantly lower than those of normal controls (0.053% and 1031%)(P<0.001). The expression level of BTLA and HVEM on cell surface of peripheral lymphocytes was not significantly different from that in normal controls (P=0.3031 and 0.2576), however, the proportion of peripheral blood T lymphocytes in patients with CMML (median: 37.73%) was significantly lower than that in controls (median 69.23%)(P=0.0005). The expression of BTLA on the surface of γδ T cells in peripheral blood of patients with CMML (median: 23.26%) was significantly lower than that of the controls (median: 52.64%) (P<0.05), and there was no significant abnormality in HVEM expression (P=0.2791). CONCLUSION: The expression of BTLA and its ligand HVEM, the proportion of T lymphocytes and the expression of BTLA on the surface of γδ T cells in patients with CMML are reduced. The effects of these abnormalities on T cell function and prognosis and efficacy of patients need to be further observed.

[Regulatory Effect of Exosomes Derived from Human Umbiilcal Cord Mesenchymal Stem Cells on Treg and TH17 Cells].

OBJECTIVE: To investigate the effects of exosomes from human umbilical cord mesenchymal stem cells on the development of Treg and TH17 cells. METHODS: Exosomes from the serum-free-culture supernatants of hUC-MSC were harvested by ultracentrifugation. The electron microscopy, nanoparticle tracking analysis and western blot were used to identify the hUC-MSC-exosomes, such as the morphology, the paticle chameter, and the protein content. The PBMC stimulated with anti-CD3/CD28 were incubated with the exosomes for five days, and then the percentage changes of Treg and TH17 cells were analyzed by using flow cytometry. RESULTS: The hUC MSC-derived exosomes were saucer-like in morphology the averge diameter was approximately 142 nm. They were identified as positive for CD9 and CD63. Flow cytometry showed that the proportion of CD4+CD25+Foxp3+ Treg cells in the PBMC were significantly higher, but the proportion of CD4+IL17A+ T cells in the hUC-MSC-exosome group was obviously lower than that in the group without the hUC-MSC-exosom (control group) (P<0.05). CONCLUSION: The hUC-MSC-exosomes have an immunomodulatory effect on T cells in vitro by increasing the ratio of Treg and reducing the ratio of TH17 cells, expecting the hUC-MSC-exosom as a novel cell-free target for immunotherapy.

Allogeneic Bone Marrow-Derived Mesenchymal Stromal Cells Expanded In Vitro for Treatment of Aplastic Anemia: A Multicenter Phase II Trial.

We conducted a phase II, noncomparative, multicenter study to assess the efficacy and safety of allogeneic bone marrow-derived mesenchymal stromal cells (BM-MSCs) expanded in vitro for patients with aplastic anemia (AA) refractory to immunosuppressive therapy. Seventy-four patients from seven centers received allogeneic BM-MSCs at a dose of 1-2 × 106 cells/kg per week for 4 weeks. Responses were assessed at 0.5, 1, 2, 3, 6, 9, and 12 months after the first cells infusion. Patients with response at 1 month continued to receive four infusions. All patients were evaluable. The overall response rate was 28.4% (95% confidence interval, 19%-40%), with 6.8% complete response and 21.6% partial response. The median times to response of leukocytic, erythrocytic, and megakaryocytic linages were 19 (range, 11-29), 17 (range, 12-25), and 31 (range, 26-84) days, respectively. After median follow-up of 17 months, overall survival was 87.8%. Seven patients developed transitory and mild headache and fever, but no other adverse events were observed. Antithymocyte globulin used in previous treatment and no activated infection throughout treatment were predictors for response. Allogeneic BM-MSCs infusion is a feasible and effective treatment option for refractory AA. The trial was registered at www.clinicaltrials.gov as NCT00195624. Stem Cells Translational Medicine 2017;6:1569-1575.

[Effectiveness of CLAT Protocol for Treating Patients with Refractory Acute Myeloid Leukemia].

OBJECTIVE: To explore the clinical efficacy and toxicity of CLAT protocol (cladribine, cytarabine and topotecan) for treating patients with refractory acute myeloid leukemia (R-AML). METHODS: A total of 18 patients with R-AML (median age 37 years, range 18 to 58 years; male n = 16, female n = 2) were treated with CLAT protocol, which consisted of cladribine 5 mg/m(2)/d, i.v. on days 1-5, cytarabine 1.5 g/m(2)/d, i.v. on days 1-5, topotecan 1.25 mg/m(2)/d, i.v. on days 1-5 and G-CSF 300 µg/d subcutaneous injection on day 6 until neutrophile granulocyte recovery. RESULTS: Out of 18 patients 2 died of severe infection before the assessment. Among 16 evaluated patients, 10 (55.6%) achieved complete remission (CR), and 2 (11.1%) achieved partial remission (PR), the overall response rate was 66.7%, the rest 4 patients did not respond (NR). The median overall survival time and DFS for the CR patients was 9.5 months (95%CI: 6.7-16.64) and 9.5 months (95%CI: 6.1-16.7) respectively. The 1 year OS and DFS rates were 45% and 46.9%, respectively. All patients developed grade 4 of granulocytopenia and thrombocytopenia, the median duration was 13 (range 2 to 21) days and 12 days (range 2 to 21), respectively, all patients developed infection, 2 patients died of severe infection. The most common non-hematological side effects included nausea, vomiting, diarrhoea, rash, aminotransferase or bilirubin elevation and were grade 1 to 2. CONCLUSION: The CLAT protocol seems to have promising for the treatment of refractory AML patients, and patients well tolerated. This CLAT protocol offers an alternative treatment for R-AML patients who received severe intensive treatment, especially with anthracycline-containing chemotherapy.

[C-kit mutation in acute myeloid leukemia patients with AML1-ETO fusion gene and its clinical significance].

This study was aimed to investigate the c-kit mutation in acute myeloid leukemia (AML) patients with AML1-ETO and analyze its relation with clinical and laboratorial features and prognosis. PCR and sequencing methods were used to detect the c-kit 17 exon mutations in 31 AML patients with AML1-ETO. The relation of the c-kit mutation with clinical features, results of laboratorial examination and prognosis of disease were analyzed. The results showed that the c-kit mutation was found in 14 out of 31 AML patients and the mutation frequency was 45.16%. Male patients had a higher incidence of c-kit mutation than that of female patients (P = 0.020). The proportion of patients with newly diagnosed white blood cell>10×10(9)/L and with extramedullary infiltration in mutated group were higher than those in unmutated group respectively. No significant difference was observed at the age (P = 0.437) and the rate of bone marrow blasts(P = 0.510) between the above mentioned two groups. The difference in complete remission rate (64.29% vs 80%, P = 0.344)and relapse rate (58.33% vs 21.43%, P = 0.054) between c-kit mutated and c-kit unmutated groups were not significant. While the c-kit mutated group had a significant higher death rate as compared with c-kit unmutated group (57.14% vs 20%, P = 0.039). It is concluded that the c-kit mutation is frequent in AML patients with AML1-ETO and the c-kit mutated patients have a poor prognosis. It is important to detect c-kit mutation in routine clinical practice for patient's risk stratification, evaluation of prognosis and selection of effective treatment.

[Predictive value of molecular response after treatment with tyrosine kinase inhibitor for 3 months in patients with chronic myeloid leukemia].

OBJECTIVE: To understand the predictive value of early monitoring BCR-ABL transcripts in patients with chronic myeloid leukemia (CML) after treatment with tyrosine kinase inhibitor (TKI), and to provides the information for early assessment of prognosis and treatment options. METHODS: BCR-ABL transcripts of 53 CML patients before and after TKI treatment were detected by using real-time quantitative RT-PCR. The relationship between BCR-ABL transcripts level after TKI treatment for 3 months and the later molecular response, progression and mutation was analyzed. RESULTS: The median values of BCR-ABL transcripts in peripheral blood samples from 30 newly diagnosed patients were 43.99%, which was used as a baseline of BCR-ABL transcripts for molecular response evaluation. Of 53 patients, 31 (58.49%) had a BCR-ABL mRNA ≤ 4.40% (reduced more than 1 log) and 22 (41.51%) greater than 4.40% (reduced to less than 1 log) after 3 months of TKI treatment. The former 31 patients had a significantly higher 18-months cumulative incidence of major molecular response (MMR) (90.32% vs 18.18%, P=0.000) and 3-year cumulative incidence of complete molecular response (CMR) (48.39% vs 0, P=0.000) compared with the latter 22 patients. The lower BCR-ABL level was, the earlier MMR reached. The proportion of patients with a mutation in group of BCR-ABL mRNA>4.40% was significantly higher than that of BCR-ABL mRNA ≤ 4.40% (22.73% vs 0, P=0.021). The incidence of progression increased in group of BCR-ABL mRNA>4.40%, but the difference was not statistically significant (P=0.052). CONCLUSION: It is important for the prognosis evaluation of the patients to monitor the level of BCR-ABL transcripts at 3 months after TKI treatment, which might help to early optimization of treatment and to improve curative effect of CML patients.

[Clinical study of intravenous injecting itraconazole as empirical antifungal therapy for patients with hematological malignancies].

This study was purposed to investigate the efficacy and safety of intravenous injecting itraconazole (ITCZ) as empirical antifungal therapy in the patients with hematological malignancies. According to recommendation in IDSA guidebook, the patients suffered from fever during neutropenia and inefficacy of treatment using broad-spectrum antibiotics for 4 days should receive intravenous injection of ITCZ as empirical antifungal therapy. The results showed that the overall clinical response rate to ITCZ injection was 62.9% (22/35), and the success rate of achieving composite endpoints was 54.3% (19/35). Mild adverse reactions were observed in 6 patients (17.1%). The injection of ITCZ was stopped in 2 patents (5.7%) due to adverse reaction. Further analysis revealed that the response rate was higher in patients with fever prior to the start of ITCZ within five days than beyond five days (P = 0.031). The response rate was higher in patients with possible invasive fungus infection (IFI) than that in patients with probable and confirmed IFI (P = 0.002). The prophylactic antifungal treatment during neutropenia displayed no significant influence on efficacy of empirical antifungal therapy with itraconazole (P = 0.054). It is concluded that the good efficacy and safety of empirical ITCZ injection for hematological malignancies patients is efficient and safe.

[A method for induction of mouse CD8α(+);CD11b(+);jagged2(high);regulatory dendritic cells with mesenchymal stem cells in vitro].

AIM: To develop a method for induction of the mouse bone marrow-derived CD8α(+);CD11b(+);jagged2(high);regulatory dendritic cells (DCregs) using mesenchymal stem cells (MSCs) in vitro. METHODS: BALB/c(H-2(d);)mouse bone marrow cells (BMCs) were isolated and induced to CD8α(+);CD11c(+);CD11b(+);DCs (DCs) by 4 cytokines in vitro for 3 d. The DCs were selected by flow cytometry (FCM), and co-cultured with MSCs for 10 d to get DCregs. Immunophenotypes, cell cycle, Jagged1 and Jagged2 ligands of the Notch pathway of DCs were analyzed by FCM before and after co-culture. RESULTS: The novel DCs were transformed into DCregs successfully. The expressions of CD86, CD80, CD40, and MHC-II significantly decreased (P<0.05), while those of CD205, Jagged1 and Jagged2 obviously increased on DCregs (P<0.05). Meanwhile, the percentage of treated MSCs cells went up in G2 and S phases. CONCLUSION: MSCs co-cultured with DCs can induce the development of DCregs, which have immune tolerance-associated phenotypes and higher proliferation ability. This mechanism might be related to the up-regulated Jagged1 and Jagged2 expressions and the T-cell Notch pathway activation.

[A preliminary study on clinical diagnostic value of plasma elafin in skin acute graft-versus-host disease].

OBJECTIVE: To analyze the specificity, sensitivity and receiver operating characteristic (ROC) curve of plasma elafin for diagnosis of skin acute graft-versus-host disease (aGVHD), and to explore its clinical diagnostic value. METHODS: Incidence of skin aGVHD from fifty-three patients received allogeneic hematopoietic stem cell transplantation (allo-HSCT) were observed prospectively in Guangdong General Hospital from Apr 2010 to Aug 2011. The plasma concentrations of elafin were detected by enzyme-linked immunosorbent assay (ELISA). Skin biopsies were taken from 28 patients with skin rash, and elafin expression in the skin was detected by immunohistochemistry. Positive expression was defined as significant staining of at 50% of the depth of the epidermis, excluding the granular cell layer and the acrosyringium. RESULTS: Among 28 patients with skin rash, twenty-five were considered as skin aGVHD by clinical diagnosis, seventeen were confirmed as skin aGVHD by pathological biopsy. 11 cases were elafin positive by immunohistochemical staining. Elafin protein was overexpressed in aGVHD skin tissue (P = 0.001). Plasma concentrations of elafin were significantly higher in patients with skin aGVHD (positive) group than in those without skin aGVHD (negative) group (P = 0.005), among which there being no statistically significant difference in plasma elafin level between patients with grade I skin aGVHD group and negative group(P = 0.971), but being statistically significant difference compared patients with grade II-IV skin aGVHD group with those with grade I skin aGVHD group (P = 0.02) and with negative group (P = 0.008). Using the pathological diagnosis as the gold standard, the estimated specificity and the sensitivity of clinical diagnosis criteria were 27.3% and 100%, respectively, and those of tissue elafin protein level were 100% and 64.7%, respectively. The area under the ROC curve was 0.909 (0.797 - 1.021) when plasma concentrations of elafin was used in diagnosis of skin aGVHD. The sensitivity was 82.4% and the specificity was 81.8 % when the critical value was set at 1456.043 µg/L. CONCLUSION: Plasma concentration of elafin is significantly higher at the onset of skin aGVHD. It can be used as biochemical marker of skin aGVHD and has higher value in diagnosis of skin aGVHD.

[Detection of methylation levels of multi-genes by real-time PCR in patients with myelodysplastic syndrome].

OBJECTIVE: To analyze the promoter methylation levels of p15, CDH1, DAPK and HICI genes of patients with myelodysplastic syndrome (MDS) and explore the relationship between the level of methylation and clinical features. METHODS: DNA methylation levels of p15, CDH1, DAPK and HICI in peripheral blood (PB) or bone marrow (BM) samples from 52 MDS patients were detected by real-time quantitative PCR. The correlation of the methylation level with clinical features and hematological findings was analyzed. 38 de novo AML patients and 46 normal individuals served as controls. RESULTS: The methylation levels of p15, CDH1, DAPK and HICI were 16.23 ± 21.69, 6.59 ± 9.39, 0.14 ± 0.11 and 7.81 ± 9.70 in BM, and 14.96 ± 20.16, 6.00 ± 9.26, 0.12 ± 0.14 and 6.74 ± 9.72 in PB, respectively from 18 MDS patients, and the difference between BM and PB was not statistically significant (P > 0.05). The methylation levels of p15 (14.70 ± 18.17) and CDH1 (6.61 ± 8.79) genes in high risk (RAEBI/II) MDS were significantly higher than in low risk (RCMD/RARS/5q-, p15: 1.99 ± 1.59, CDH1: 1.23 ± 1.14 and RCMD, p15: 3.02 ± 3.42, CDH1:1.53 ± 2.06) MDS or control (p15: 1.69 ± 1.82, CDH1: 1.01 ± 1.12) (P < 0.05). The methylation levels of DAPK gene had no difference among subtypes of MDS, and that of HIC1 gene only differed between RAEB I/II (9.16 ± 11.95) and control (2.49 ± 2.26) (P = 0.042). The difference of methylation levels of p15, CDH1, DAPK and HICI in BM was statistically significant among subtypes of MDS (P = 0.001, 0.003, 0.039, 0.023, respectively). And so did of p15 and DAPK in PB (P = 0.013, 0.006, respectively). The methylation level of p15 and CDH1 was significantly correlated with IPSS classification and blasts percentage in BM. CONCLUSIONS: p15 and CDH1 genes are special hypermethylation genes in MDS. Methylation level of HIC1 gene showed an upward tendency from low risk to high risk MDS.

[Expression of CD133 in the bone marrow of patients with myelodysplastic syndrome and its clinical significance].

OBJECTIVE: To investigate the expression of CD133 in the bone marrow of patients with myelodysplastic syndrome (MDS) and explore its clinical significance. METHODS: The expression of CD133 and CD34/CD38 in the bone marrow was detected using flow cytometry in 31 cases of refractory anemia with excess blasts (RAEB), 10 cases of refractory cytopenia with multilineage dysplasia (RCMD) and 11 cases of aplastic anemia (AA). RESULTS: The percentage of CD133-expressing cells was 6.75% in patients with RAEB, significantly higher than that in patients with RCMD (1.41%) and AA (2.70%) (P<0.05); the percentage of CD133-positive cells were similar between the latter two patient groups (P>0.05). The percentage of CD34(+)/CD38- cells was similar in the 3 groups (P>0.05), all lower than 1%. CONCLUSIONS: Advanced MDS patients are characterized by an increase of CD133-expressing cells, suggesting the value of CD133 in the diagnosis of RAEB. CD34(+)/CD38- cells do not show a significant value in the diagnosis of MDS.

[Expression of antiapoptotic gene aven in de novo acute myeloid leukemia patients and its clinical significance].

This study was aimed to investigate the aven mRNA expression level of leukocytes from peripheral blood(PB)of de novo patients with acute myeloid leukemia (AML) and analyze its clinical significance, so as to provide a experimental basis for evaluating prognosis. The aven mRNA expression levels in PB samples from 69 de novo AML patients were detected by using real-time quantitative PCR. The relation of aven mRNA level with clinical and hematological characteristics (age, sex, WBC, Hb, Plt, LDH, Blast% in PB and BM, FAB subtype) and treatment outcome (CR rate and relapse rate) were analyzed. 21 normal individuals served as controls. The results showed that the expression level of aven mRNA was between 11.72% and 178.93% (median 37.2%) in de novo AML and between 10.81% and 50.98% (median 28.81%) in normal individuals. Aven mRNA expression level was higher in the AML group than that in the controls (p = 0.006). As aven mRNA expression level was compared with other clinical and hematological parameters, there were significant correlations between aven mRNA expression level and age (r = 0.25, p = 0.039), and between hemoglobin level (r = 0.29, p = 0.019), FAB subtype(r = 0.253, p = 0.036). The median expression level (50.08%) of aven mRNA in older patients (> or = 44 years) was higher then that (32.41%) in younger patients (< 44 years) (p = 0.018). The complete remission (CR) rate after two cycles of chemotherapy in patients with lower aven mRNA level (25/30, 83.33%) was higher than that in patients with higher aven mRNA level(21/30, 70%), but the difference was not significant(p = 0.22). The difference of aven mRNA expression level between AML patients with relapse and AML patents without relapse was not significant (p = 0.076). It is concluded that the expression level of aven mRNA in de novo AML patients obviously increases, the overexpression of aven mRNA likely involves in genesis of AML. The definite relation of aven mRNA expression level with treatment outcome and relapse was not been found.

[Role of nitro oxide in immunosuppressive effect of human mesenchymal stem cells on allogenic proliferative response of lymphocytes].

The purpose of this study was to investigate the influence of nitro oxide (NO) from mesenchymal stem cells (MSC) on the proliferative responses of allogeneic lymphocytes and its mechanism. MSCs were isolated and cultured from human bone marrow. Selected surface antigens of MSCs were detected by flow cytometry and their morphologic characteristics were determined by microscopy. Mitomycin C-treated MSCs were plated in dishes and then mixed lymphocyte cultures (MLC) were set up. After 4 days, lymphocyte proliferation was determined by CCK-8 assays; NO secretion in coculture supernatant was determined by Griess reagent kit; the level of FOXP3 mRNA expression was detected by real-time quantitative PCR. The results indicated that in MSC/MLC coculture experiment, the lymphocyte proliferation decreased significantly with of IOD value 0.49+/-0.03, NO production increased obviously (21.05+/-1.14 micromol/L) and FOXP3 mRNA expression was increased [(1.56+/-0.34)%] as compared with MLC coculture without MSC. There were significant difference between these two groups. It is concluded that NO production in human MSC culture up-regulates FOXP3 mRNA expression and thus inhibits lymphocyte proliferation response.