Low-dose venetoclax combined with azacitidine for blastic plasmacytoid dendritic cell neoplasm: a case report and literature review.

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare hematologic malignancy that is highly aggressive with a poor prognosis. There is no standard treatment for BPDCN. Although conventional chemotherapies are usually sensitive in the initial therapy, relapse and drug resistance are inevitable within a short duration. Targeted therapies have enlightened new prospects for the treatment of BPDCN, especially for those in a frail state and intolerable to standard chemotherapies or hematopoietic stem cell transplantation. Here, we report an 82-year-old man diagnosed with cutaneous-limited BPDCN. Considering the old age and limited involvement of the tumor, we reduced the dosage of venetoclax. His skin lesions subsided significantly after 1 cycle of azacytidine (100 mg d1-7) combined with reduced doses of venetoclax (200 mg d1-14). The reduction in the dose of venetoclax avoided severe myelosuppression while achieving satisfactory outcomes. The patient received 2 cycles of therapy with no skin lesions re-occurred for 7 months before relapsing.

[JAK2 V617F mutation burden and its clinical implications in 415 patients with myeloproliferative neoplasm].

OBJECTIVE: To detect JAK2 V617F mutation burden and its clinical implications in patients with myeloproliferative neoplasm (MPN). METHODS: JAK2 V617F mutation burden were detected by using MGB Taqman probes and its clinical significance were retrospectively studied in 415 MPN patients. RESULTS: JAK2 V617F was found in 56.9% of all patients [83.5% in polycythemia vera (PV), 55.9% in essential thrombocythemia (ET), 41.9% in primary myelofibrosis (PMF) and 64.7% in MPN-unclassifiable)]. The majority of patients carried heterozygous JAK2 V617F mutation and homozygote was found only in 12 cases (4 in PV, 4 in MPN-U, 2 in PMF, 1 in ET, and 1 in chronic neutrophilic leukemia). Most patients (68.8%) were lower mutation burden (mutation burden<50%), but PV had the highest burden, the moderate burden in PMF and the least in ET. The patient's age and WBC count were significantly correlated with higher mutation burden in PV. WBC count was significantly related to higher mutation burden in ET. WBC count, Hb level and the platelet count were significantly related to higher mutation burden in PMF. CONCLUSION: The mutation burden of JAK2 V617F from high to low was PV, ET and PMF. The majority of JAK2 V617F mutation was heterozygous. JAK2 V617F mutation burden was positively correlated with age, WBC, Hb and platelet counts.

Elevated Th22 cells correlated with Th17 cells in peripheral blood of patients with acute myeloid leukemia.

Acute myeloid leukemia (AML) is a hematological tumor in which progress T helper (Th) subsets including Th22, Th17, and Th1 cells play a pivotal role. However, the role of T helper (Th) subsets in the immune pathogenesis of AML remains unclear. Here, we investigated frequencies of Th22, Th17, pure Th17, and Th1 cells in the peripheral blood (PB) of AML patients. We demonstrated that Th22, Th17, and pure Th17 in newly-diagnosed (ND) and non-complete remission (Non-CR) AML patients and plasma IL-22 in ND AML patients were significantly increased. Retinoid-related orphan receptor C (RORC) expression was significantly elevated in CR and Non-CR AML patients. However, Th1 in ND AML patients and IL-17 in ND, Non-CR or CR AML patients was significantly decreased compared with controls. Moreover, Th22 and IL-22 showed positive correlation with pure Th17, but Th22 showed negative correlation with Th1 in ND AML patients. RORC showed positive correlation with Th22 and approximately positive correlation with pure Th17 in Non-CR patients. PB blast cell showed positive correlation with Th22 and negative correlation with Th1 in ND AML patients. Our results indicate that Th22 and pure Th17 cells conjointly contribute to the pathogenesis of AML and might be promising novel clinical index for AML.

The imbalanced profile and clinical significance of T helper associated cytokines in bone marrow microenvironment of the patients with acute myeloid leukemia.

BACKGROUND: Immunological disorder has shown to be related to the pathogenesis of acute myeloid leukemia (AML). The microenvironment of AML is immunosuppressive, favoring the survival of malignant hematopoietic cells. However, the systematic research on AML abnormal immune microenvironment, especially the T helper (Th) cells imbalance, remains unsettled. DESIGN AND METHODS: The levels of cytokines in bone marrow plasma including Th1-associated cytokine (IFN-γ), Th2-associated cytokine (IL-4), Th17-associated cytokines (IL-17, IL-6, TGF-ß, and IL-21), regulatory T cell (Treg)-associated cytokines (IL-35 and IL-10) and Th22-associated cytokine (IL-22) were examined by enzyme-linked immunosorbent assay (ELISA) in AML patients and controls. The relative expression levels of IL-4, IL-10, and IL-21 mRNA were analyzed by real time polymerase chain reaction (PCR). RESULTS: Significant differences on cytokine levels tested were observed among the AML newly-diagnosed (ND) patients, AML patients in complete remission (CR) and controls except IL-21 and IL-35. In AML-ND group IFN-γ level was positively correlated with IL-21 or IL-22 level. Additionally, significant associations were observed between IL-17, IL-21 and some clinical characteristics. CONCLUSION: Our results showed that many cytokines were abnormal in AML bone marrow microenvironment. The dysregulation of Th subsets cytokines is thought to contribute to the pathogenesis of AML.

[Monitoring of plasma concentration of imatinib mesylate in patients with chronic myeloid leukemia].

OBJECTIVE: To analyze the clinical efficacy of imatinib mesylate (IM) for Ph-positive or BCR-ABL positive chronic myeloid leukemia (CML) to couple the trough plasma concentrations (C mins) of IM with clinical responses and adverse events (AEs). METHODS: One hundred and one CML patients received IM therapy, and Cmins of IM were determined in 30 patients. RESULTS: (1) Cumulative complete hematological response (CHR), major cytogenetic response (MCyR), complete cytogenetic response (CCyR) and negative BCR/ABL fusion gene rates were 96.6%, 86.5%, 77.5% and 47.2%, respectively, in CML-CP patients. In accelerated and blastic phases (AP and BC) patients, CHR, MCyR, CCyR and negative BCR-ABL fusion gene rates were 58.3%, 25.0%, 25.0%, 8.3%, respectively. (2) Mean Cmins of IM was significantly higher in the CCyR at 1 year [(1472 +/- 482) microg/L] group than in the non-CCyR at 1 years group [(1067 +/- 373) microg/L] (P < 0.05), and higher in the MMR at 1 year group than in the non-MMR at 1 years group [(1624 +/- 468) microg/L vs (1137 +/- 404) microg/L, P < 0.05]. CONCLUSION: IM significantly improves cytogenetic and molecular response, event-free survival, and overall survival for patients with Ph-positive CML. The Cmins of IM exerts a significant impact on clinical response (CCyR and MMR at 1 year).

[Synergistic effect of DNA methylation inhibitor and histone deacetylase inhibitor on RASSF1A gene expression in U266 cells.].

OBJECTIVE: To investigate the effect of DNA methylation in combination with histone deacetylase inhibitor on transcription regulation of Ras associated domain family gene 1(RASSF1A) tumor suppressor gene and the molecular biological behaviors in U266 cells. METHODS: The U266 cells were treated with different doses of 5-Aza-2'-deoxycytidine (5-Aza-CdR) and Valproate (VPA) each alone or in combination. Methylation-specific PCR (MSP) was used to detect CpG island methylation in RASSF1A promoter. Quantitative real-time reverse transcription polymerase chain reaction (RQ-PCR) was used to examine the expression of RASSF1A gene in U266 cells. MTT was used for cell proliferation. Cell apoptosis and cell cycle were analyzed by flow cytometry. RESULTS: The methylation of RASSF1A gene promoter was detected in U266 cells, while there was little RASSF1A gene expressing in the control group. The demethylation effect could be detected in the 5-Aza-CdR treated and combined treatment groups but no in the VPA group. The expression level of RASSF1A was induced by 5-Aza-CdR in a concentration-dependent manner while VPA had no such effect. The expression level of RASSF1A mRNA was increased significantly in the combined treatment group. Higher growth inhibition and apoptosis effects were found in 5-Aza-CdR and VPA combination group than that in 5-Aza-CdR or VPA alone group (P < 0.05). After treatment with 5-Aza-CdR or VPA alone for 72 h, more cells were arrested in G(0)/G(1) phase as conpared with control group (P < 0.05), and even more cells were so arrested in combined treatment group (P < 0.05). CONCLUSION: DNA methylation and histone deacetylase inhibitor can synergistically induce demethylation of the RASSF1A gene, re-express RASSF1A gene silenced in U266 cells, inhibit the proliferation of U266 cells and induce cell apoptosis.

[Effect of CD44 gene silence on multi-drug resistance reversal and biologic activity in K562/A02 cells].

This study was aimed to investigate the effect of CD44 gene silence on the drug resistance and biologic activity of human multidrug resistant leukemia cell line K562/A02. The oligonucleotides of CD44 gene were designed according to related data of GenBank, double-stranded DNA was produced by annealing, and was inserted into pGCsilencerU6/Neo/GFP vector. The resultant recombinant plasmid pGCsiRNA-CD44 was transfected into K562/A02 cell line. Expressions of CD44, mdr-1 and blc-2 mRNA were assayed by real time RT-PCR. The 50% inhibitory concentration (IC50) of doxorubicin (ADM) for K562/A02 cell line was determined by MTT method. Cell cycle was determined by flow cytometry. The morphology of apoptotic cells was examined by Hochst 33258 staining. The results indicated that the siRNA eukaryotic plasmid directing at CD44 gene could effectively silence the CD44 gene of K562/A02 cells; as compared with control group, the CD44 expression in K562/A02 cells transfected with 4 pGCsiRNA-CD44 plasmids was obviously inhibited, while the inhibition of CD44 expression in cells transfected with siCD44-1 was strongest. After being transfected with pGCsiRNA-CD44, the expression of CD44 mRNA in K562/A02 cells reduced by 64.1% (p<0.05), at the same time the expression of mdr-1 and bcl-2 mRNA in pGCsiRNA-CD44-transfected K562/A02 cells reduced by 25.6% and 50.8% respectively. IC50 of K562/A02 cells after transfection decreased to (8.77+/-1.63) microg/ml and was obviously lower than that of control (17.97+/-1.61) microg/ml (p<0.01). After transfection for 48 hours, the ratio of K562/A02 cells in G0/G1 increased by 10.7%, and the cells displayed karyopyknosis, nuclear margination and apoptotic bodies. It is concluded that the siRNA plasmid specifically targeting CD44 gene can remarkably down-regulate the expression of CD44 gene, inhibit K562/A02 cell proliferation, induce its apoptosis and effectively reverse the multidrug resistance of K562/A02 cells.

Interleukin (IL)-17 promotes macrophages to produce IL-8, IL-6 and tumour necrosis factor-alpha in aplastic anaemia.

Aplastic anaemia (AA) is thought to be an autoimmune-mediated disease with active destruction of haematopoietic cells through a T helper type 1 (Th1) cell response. Interleukin (IL)-17 is a potent proinflammatory cytokine produced by activated memory T cells. Recent studies indicate that IL-17 might be an essential effector cytokine in the T-cell mediated autoimmune process. It can drive the production of tumour necrosis factor-alpha (TNF-alpha), IL-1 beta, IL-6 and IL-8 by a variety of cells. The present study investigated the genetic and protein expression of IL-17 in patients with AA. The effect of IL-17 on IL-6 and IL-8 production by macrophages was also studied. AA patients showed an elevated expression of IL17A mRNA in bone marrow mononuclear cells and peripheral blood mononuclear cells. Higher IL-17 in bone marrow and peripheral blood plasma was also observed in AA patients compared with normal controls. IL-17 induced the production of IL-6 and IL-8 by macrophages both from patients with AA and normal controls. IL-17 stimulation also resulted in the production of TNF-alpha. These results suggested that elevated expression of IL-17 and IL-17-induced IL-6, IL-8 and TNF-alpha may be involved in the mechanisms of AA.

[The effect of selectively inhibiting the nuclear factor kappaB activation on survivin expression in leukemic cells].

OBJECTIVE: To investigate the highly specific proteasomal inhibitor MG132-induced apoptosis and its effect on nuclear factor (NF)-kappaB activation and survivin expression in leukemic K562 cell line. METHODS: leukemic cells of the line K562 were cultured and divided into 2 groups: treatment group, undergoing co-incubation with MG132 of the concentrations of 2, 4, 6, and 8 micromol/L respectively for 24 hours, and control group without treatment of MG132. Apoptosis was detected by examination of cell morphology and flow cytometry. Survivin expression and NF-kappaB activation were analyzed by immunocytochemistry and Western blotting. RESULTS: MG132 induced apoptosis of the K562 cells dose-dependently. Both survivin and NF-kappaB were highly expressed in the K562 cells. Compared with the control group, K562 cell treated with MG132 at the concentrations of 2, 4, 6, and 8 micromol/L for 24 hours showed the decrease of NF-kappaB activation to 75.0% +/- 3.7%, 59.9% +/- 5.3%, 45.4% +/- 5.7%, and 25.0% +/- 4.2% respectively, and decrease of survivin expression to 90.9% +/- 10.1%, 66.7% +/- 5.2%, 45.4% +/- 5.7%, and 30.3% +/- 6.6% respectively. Downregulation of survivin expression was closely correlated with the inhibition of NF-kappaB activation (Pearson correlation coefficient = 0.989, P < 0.01). CONCLUSION: MG132 induces apoptosis of leukemic cells, and effectively inhibits the NF-kappaB activation accompanied by the downregulation of survivin expression.

[Prophylactic effect of matrix metalloproteinase inhibitor on acute graft-versus-host disease in a murine model].

OBJECTIVE: To explore the prophylactic effect of tissue inhibitor of matrix metalloproteinase (TIMP) on acute graft-versus-host disease (aGVHD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in a murine model. METHODS: The murine model of aGVHD after allo-HSCT was established by using female C57BL/b (H-2b) mouse as the donor, and male BALB/c (H-2b) as the recipient. After allo-HSCT, recipient mice were divided into 3 groups. For aGVHD prophylaxis group A was given TIMP (2 mg/d) , group B CsA (5 mg x kg(-1) x d (-1)) was given, and group C nothing. Physical signs, mean survival time (MST), peripheral blood counts and aGVHD histopathology were observed. RESULTS: Mice in group C developed typical aGVHD and 100% of mortality, with a MST of 8 days, and those in group A and B had longer survival, the MST being (4.8 +/- 1.4) d and (4.3 +/- 0.9) d respectively, with no statistical difference in peripheral blood count between these two groups. Mice in group A showed less severe signs. CONCLUSIONS: TIMP markedly prolongs MST of allo-HSCT recipients, delays the onset of aGVHD signs, and has no adverse effect on hematopoiesis reconstitution.

[Effect of anti-CD49d monoclonal antibody on mobilization of CD34 positive cell into peripheral blood in mice].

To study the mobilization of peripheral blood stem cells (PBSC) with anti-CD49d monoclonal antibody and try to find a new method for mobilization of PBSC, anti-CD49d McAb, rhG-CSF and combination of anti-CD49d McAb with rhG-CSF were administered subcutaneously to mice separately, the count of white blood cells (WBC) and percentage of CD34(+) cells in peripheral blood of donor mice were dynamically observed, CD34 positive cells obtained by above methods were transfused to recipient mice. The results showed that the count of WBC and percentage of CD34(+) cells in peripheral blood of donor mice elevated significantly after the administration of anti-CD49d McAb, rhG-CSF or combination of anti-CD49d McAb with rhG-CSF. The most effective method for mobilization is the combination of rhG-CSF with anti-CD49d McAb. Reconstitution of hematopoiesis was successful in all group recipient mice after transplantation. Most rapid hematopoietic recovery was observed in recipient mice by rhG-CSF plus anti-CD49d McAb for mabilization. In conclusion, anti-CD49d McAb is effective and synergistic with rhG-CSF in mobilization of CD34 positive cells from bone marrow into peripheral blood.

Effect of arsenic trioxide on cytokine expression by acute promyelocytic leukemia cells.

OBJECTIVE: To detect the expression of cytokines by acute promyelocytic leukemia (APL) cells before and after exposure to arsenic trioxide. METHODS: Diagnoses were performed according to the FAB cytological classification criteria and cytogenetic criteria. Bone marrow or blood samples from APL patients were collected in heparinized tubes, then primary APL cells were separated by traditional Ficoll-Hypaque density centrifugation and purified after adherence to plastic surfaces. IL-1(beta), IL-6, IL-8, TNF alpha and G-CSF levels in the leukemia cell culture supernatants were detected by ELISA. At the same time, nitro blue tetrazolium (NBT) reduction test was used to detect the differentiation of APL cells. RESULTS: After 96 hours exposure to arsenic trioxide, 10 - 6 mol/L in vitro or 10 mg/d in vivo, APL cells showed a significant increase of IL-1(beta) (P < 0.05) and G-CSF (P < 0.05) production, and a significant decrease of IL-6 (P < 0.05) and IL-8 (P < 0.05). However, there was no obvious variation of TNF alpha when compared with APL cells without exposure to arsenic trioxide. On the other hand, the proliferation ratio of APL cells in vitro was statistically correlated to the IL-1(beta) secretion ratio or G-CSF secretion ratio. The cell number ratio in patients with detectable IL-1(beta) or G-CSF was higher than that without detectable IL-1(beta) or G-CSF. CONCLUSION: IL-1(beta) and G-CSF secretion may play an important role in the proliferation of APL cells after exposure to arsenic trioxide.

The TNF2 allele is a risk factor to severe aplastic anemia independent of HLA-DR.

Severe aplastic anemia (SAA) is a disease with an autoimmune component. The susceptibility to the development of SAA is strongly associated with genes in the major histocompatibility complex (MHC). The gene for tumor necrosis factor-alpha (TNF-alpha) is encoded in the MHC locus and TNF-alpha is involved in the pathogenesis of SAA. A TNF-alpha variant with a polymorphism at position -308 in its promoter region (-308A), which is designated TNF2, has been demonstrated to be linked to a number of autoimmune diseases. In this study, the TNF-alpha -308 promoter polymorphism and HLA-DRB1 alleles were analyzed in 75 SAA patients, 55 mild aplastic anemia patients (MAA), and 128 controls. In SAA the phenotype frequencies of TNF2, HLA-DR3, and -DR2 were significantly higher in comparison to controls. Stratification analysis confirmed that the TNF2 allele contributes to the susceptibility to SAA independently of HLA-DR3 or -DR2. The results indicated that TNF2 might act as an independent risk factor for SAA.