Activation of the HMGB1-TLR4 pathway impacts the functionality of bone marrow mesenchymal stem cells and disrupts macrophage polarization in immune thrombocytopenia.

Recent evidence suggests that immune thrombocytopenia (ITP), a common bleeding disorder, is linked to an imbalance in macrophage polarization and impaired bone marrow mesenchymal stem cells (BMSCs). However, the relationship between macrophage polarization imbalance and functional defects in BMSCs, as well as the involvement of associated molecules in BMSCs' defects, is not well understood. This study aimed to investigate the regulatory effects of high mobility group protein 1 (HMGB1) on the physiological functions of BMSCs, specifically in relation to macrophage polarization imbalance. Patients with ITP showed dysregulation in monocyte/macrophage polarization and impaired BMSCs function. HMGB1 was found to have a negative impact on the ability of BMSCs to regulate the imbalance in macrophage polarization, especially when inflammatory factors are present. The MyD88-dependent pathway downstream of BMSCs was found to be significantly enhanced with HMGB1 treatment. Furthermore, treatment with toll-like receptor 4 (TLR4) inhibitors successfully restored the regulatory capacity of BMSCs in ameliorating macrophage polarization imbalance and effectively inhibited the activation of the MyD88-dependent pathway. Meanwhile, infusion of si-TLR4-BMSCs reversed HMGB1-induced platelet dysfunction and reduced over-polarization to M1-like macrophages in the ITP mouse model. Consequently, targeting the HMGB1-TLR4 pathway could be a potential approach to restore the immunoregulatory function of BMSCs.

Prognostic and therapeutic significance of XPO1 in T-cell lymphoma.

T-cell lymphoma (TCL) is a highly heterogeneous group of invasive non-Hodgkin lymphoma with adverse prognosis and limited treatment options. The relationship between TCL and Exportin-1 (XPO1), a major nuclear export receptor, has not been established yet. We here investigated the prognostic role and therapeutic implication of XPO1 in TCL. We analyzed XPO1 expression in a cohort of 69 TCL tumors and found that XPO1 was over-expressed in 76.8% of TCL and correlated with decreased progression-free survival (PFS) and overall survival (OS). In vitro treatment of TCL cell lines with KPT-8602, the second-generation selective inhibitor of nuclear export (SINE), inhibited XPO1 expression and showed significant anti-proliferative, cell-cycle arrest and pro-apoptotic efficacy. In mechanism, KPT-8602 restored the localization of cytoplasmic FOXO3A, p27, p21, IκBα and PP2A into the nucleus, leading to AKT and NF-κB deactivation. Our data demonstrate for the first time that XPO1 could be an unfavorable prognostic factor for TCL, and provide a rationale for further investigation of the efficacy of KPT-8602 in TCL patients.

A phase 2 study of sorafenib combined with conventional therapies in refractory central nervous system leukemia.

BACKGROUND: Patients with refractory central nervous system leukemia (CNSL) have a dismal prognosis and lack effective therapy. Case reports have shown that sorafenib is effective against brain metastases, including leukemia. METHODS: To explore the efficacy of sorafenib combined with conventional therapies for refractory CNSL, a phase 2 study was conducted. The primary end point was the complete remission rate (CRR) within 8 weeks of treatment. Secondary end points included the overall response rate (ORR), event-free survival (EFS), overall survival (OS), and adverse events (AEs). RESULTS: Twenty-six patients with refractory CNSL were enrolled; they included 17 with isolated CNSL, 7 with hematological relapse, and 2 with another extramedullary relapse. After 8 weeks of treatment, 21 patients achieved complete remission, 2 achieved partial remission, and 3 achieved no remission for a CRR of 80.8% (95% CI, 62.1%-91.5%) and an ORR of 88.5% (95% CI, 71.0%-96.0%). Twenty patients survived, and 6 died. The 2-year EFS and OS rates were 75.0% (95% CI, 54.5%-88.3%) and 76.9% (95% CI, 54.2%-90.4%), respectively. Six patients experienced grade 3 or 4 treatment-related AEs, including moderate chronic graft-vs-host disease (n = 3), grade 3 or 4 acute graft-vs-host disease (n = 2), and grade 3 skin rash (n = 1). No treatment-related deaths occurred during the therapy of refractory CNSL. CONCLUSIONS: Sorafenib combined with conventional therapies is effective and safe for refractory CNSL. LAY SUMMARY: Sorafenib combined with conventional therapies is effective and safe for refractory central nervous system leukemia.

Comparative efficacy and safety of eleven induction chemotherapy regimens for young adult patients with newly diagnosed acute myeloid leukemia: a network meta-analysis.

The optimal induction chemotherapy regimens for young adult patients with newly diagnosed acute myeloid leukemia (AML) are not well-defined since the lack of direct comparisons between emerging treatments. Network meta-analysis (NMA) is a statistical tool to integrate direct and indirect evidence to evaluate the effect of multiple interventions. Thus, we conducted an NMA to systematically assess the efficacy and safety of different inductions for these patients. PubMed, Embase, Cochrane Library, and Web of Science were searched from establishment to 2020-03-11. Randomized controlled trials (RCTs) using different inductions were included. We deemed 11 trials eligible, including 11 inductions with 5052 participants. Relative risk (RR) and 95% confidence intervals (CIs) were calculated. In terms of complete remission (CR) rate, DAC ranked highest and was significantly higher than IA (RR = 1.27, 95% CI (1.09-1.48)) and DA (RR = 1.28, 95% CI (1.13-1.46)) (p < 0.05). The ranking of DA + Pioglitazone was second only to that of DAC, followed by HAA. For early mortality, HAD, HAA, and DA + GO were significantly higher than DA/IA (p < 0.05). DAC and DA + Pioglitazone showed similar early mortality compared to DA/IA (p > 0.05). Regarding incidence of early grade 3-4 infection, no significant differences between interventions were observed. To conclude, among the included 11 induction regimens, DAC was potentially the top choice for young adult patients with newly diagnosed AML, with highest CR rate, low early mortality, and incidence of early infection. DA + Pioglitazone and HAA also showed a superiority over the others to achieve higher CR rate, while caution should be kept in mind due to the higher early mortality of HAA.

Quercetin induces autophagy-associated death in HL-60 cells through CaMKKß/AMPK/mTOR signal pathway.

Acute myeloid leukemia (AML) is one of the most common malignancies of the hematopoietic progenitor cell in adults. Quercetin has gained recognition over the years because of its anti-cancer effect with minimal toxicity. Herein, we aim to investigate the anti-leukemia mechanism of quercetin and to decipher the signaling pathway of quercetin in HL-60 leukemic cells. We observed that quercetin induces apoptosis and autophagic cell death, in which both pathways play an important role in suppressing the viability of leukemia cells. Phosphorylated AMPK (p-AMPK) protein expressions are lower in primary AML cells, HL-60 cells, KG-1 and THP-1 cells than in peripheral blood monocular cells. After quercetin treatment, the expression of p-AMPK is increased while the expression of p-mTOR is decreased in a dose-dependent manner. Mechanistically, compound C, an AMPK phosphorylation inhibitor, upregulates the phosphorylation of mTOR and inhibits autophagy and apoptosis in quercetin-induced HL-60 cells, while silencing of CaMKKß inhibits the quercetin-induced phosphorylation of AMPK, resulting in increased mTOR phosphorylation. Furthermore, silencing of CaMKKß inhibits the autophagy in HL-60 cells. Taken together, our data delineate that quercetin plays its anti-leukemia role by inhibiting cell viability and inducing apoptosis and autophagy in leukemia cells. Quercetin inhibits the phosphorylation of mTOR by regulating the activity of AMPK, thus playing a role in the regulation of autophagy and apoptosis. CaMKKß is a potential upstream molecule for AMPK/mTOR signaling pathway, through which quercetin induces autophagy in HL-60 cells.

[Sequential intensified conditioning followed by graft-versus-leukemia induction could prevent relapse of refractory acute myeloid leukemia after allogeneic hematopoietic stem cell transplantation].

OBJECTIVE: To explore the therapeutic effects of sequential intensified conditioning regimen followed by graft-versus-1eukemia (GVL) induction in allogeneic hematopoietic stem cell transplantation (allo-HSCT) for refractory advanced acute myeloid leukemia (AML). METHODS: A total of 72 patients with refractory AML undergoing allo-HSCT from May 2001 to June 2013 were enrolled in this prospective study. Intensified conditioning included fludarabine + cytarabine plus total body irradiation + cyclophosphamide + etoposide. Cyclosporine A was withdrawn rapidly in a stepwise fashion if patients who did not experience acute graft-versus-host disease (aGVHD) at Day + 30 post-transplantation. Donor lymphocytes were infused in patients without grade II or more than grade II aGVHD at Day + 60 post-transplantation. RESULTS: The median follow-up time was 655 (1-4 200) d post-transplantation. Except for one died of infection and one died of regimen-related toxicity (RRT), the other 70 patients achieved complete remission at the time of neutrophil reconstitution. The mortality of RRT was 1.4% (1/72). The 1-year cumulative incidence of aGVHD and 2-year incidence of chronic GVHD (cGVHD) post-transplantation were 60.7% ± 5.0% and 58.5% ± 4.7%. The 5-year cumulative incidence of relapse post-transplantation was 29.6% ± 6.6%. The 5-year non-relapse mortality was 28.8% ± 6.0%. The 5-year overall and disease-free survival were 51.0% ± 6.5% and 49.9% ± 6.4%. Multivariate analysis revealed that donor lymphocyte infusion, cGVHD and bone marrow blasts at Day 0 were independent prognostic factors for relapse (HR (95% CI): 0.042 (0.007-0.688), 0.009 (0.003-0.345), 3.385 (1.451-7.899)) and survival (HR (95% CI): 0.315 (0.146-0.621), 0.416 (0.200-0.866), 1.332 (1.158-1.533)). CONCLUSION: The strategy of sequential intensified conditioning followed by GVL induction has an acceptable toxicity profile, and could decrease the relapse rate and improve the survival for refractory AML.

Antifungal agents for secondary prophylaxis based on response to initial antifungal therapy in allogeneic hematopoietic stem cell transplant recipients with prior pulmonary aspergillosis.

We performed a prospective study to evaluate the efficacy and safety of secondary antifungal prophylaxis (SAP) for patients with a history of invasive pulmonary aspergillosis (IPA) in allogeneic hematopoietic stem cell transplantation (allo-HSCT). In this study, the prophylactic agents used were chosen based on treatment response to initial antifungal therapy. One hundred and thirty-six patients undergoing allo-HSCT with prior IPA were enrolled in this multicenter study. The agents of SAP included itraconazole in 24, voriconazole in 74, caspofungin in 32, and liposomal amphotericin B in 6. Eighty-eight patients had stable IPA and 48 had active IPA at the time of transplantation. The success rate of SAP was 91.2%. Twelve patients developed breakthrough invasive fungal disease (IFD), and none discontinued antifungal agents because drug-related adverse events. The incidence of breakthrough IFD was neither different among the different antifungal agents (P = .675) nor between patients with active and stable IPA (P = .080). The 1-year cumulative incidence of IFD and IPA relapse was 27.3% ± 4.5% and 24.7% ± 4.4%, respectively. Our data indicate that SAP with antifungal agents based on initial antifungal therapy has favorable efficacy and safety in allo-HSCT recipients with prior IPA. Active IPA might not increase the risk of breakthrough IFD after transplantation.

The role of AMP-activated protein kinase in quercetin-induced apoptosis of HL-60 cells.

Our previous studies have shown that quercetin inhibits Cox-2 and Bcl-2 expressions, and induces human leukemia HL-60 cell apoptosis. In order to investigate the role of AMP-activated protein kinase (AMPK) on quercetin-induced apoptosis of HL-60 cells, we used flow cytometry to detect cell apoptosis. The expressions of LKB1, phosphorylated AMPK (p-AMPK), and Cox-2 protein were detected in HL-60 cells and normal peripheral blood mononuclear cells (PBMCs) by western blot. The expressions of LKB1, p-AMPK, and Cox-2 were detected in HL-60 cells after culture with quercetin. The expressions of p-AMPK were detected in HL-60 cells after culture with AMPK inhibitor Compound C. Then, the expressions of LKB1, p-AMPK, and Cox-2 were detected in HL-60 cells after culture with quercetin alone or quercetin + Compound C. It was found that there was no significant difference in LKB1 between PBMCs and HL-60. p-AMPK in PBMCs was higher than that in HL-60, while Cox-2 was lower. After culture of HL-60 with quercetin, p-AMPK was increased, Cox-2 was decreased, but LKB1 remained unchanged. After culture of HL-60 with Compound C, p-AMPK was decreased. There was no significant difference in LKB1 between the quercetin-alone and the quercetin + Compound C groups. p-AMPK decreased more significantly, while Cox-2 increased more significantly in the quercetin + Compound C groups than those in the quercetin-alone groups. Taken together, these findings suggested that quercetin activates AMPK expression in HL-60 cells independent of LKB1 activation, inhibits Cox-2 expression by activating AMPK, and further regulates the Bcl-2-dependent pathways of apoptosis to exert its anti-leukemia effect.

PHGDH is Key to a Prognostic Multigene Signature and a Potential Therapeutic Target in Acute Myeloid Leukemia.

As a rate-limiting enzyme for the serine biosynthesis pathway (SSP) in the initial step, phosphoglycerate dehydrogenase (PHGDH) is overexpressed in many different tumors, and pharmacological or genetic inhibition of PHGDH promotes antitumor effects. In the present research, by analyzing several acute myeloid leukemia (AML) datasets in the Gene Expression Omnibus (GEO), we identified prognosis-related genes and constructed a multigene signature by univariate, multivariate Cox regression and LASSO regression. Subsequently, the multigene signature was confirmed through Cox, Kaplan-Meier, and ROC analyses in the validation cohort. Moreover, PHGDH acted as a risk factor and was correlated with inferior overall survival. We further analysed other datasets and found that PHGDH was overexpressed in AML. Importantly, the expression of PHGDH was higher in drug-resistant AML compared to drug-sensitive ones. In vitro experiments showed that inhibition of PHGDH induced apoptosis and reduced proliferation in AML cells, and these antitumor effects could be related to the Bcl-2/Bax signaling pathway by the noncanonical or nonmetabolic functions of PHGDH. In summary, we constructed a twenty-gene signature that could predicate prognosis of AML patients and found that PHGDH may be a potential target for AML treatment.

Oral arsenic plus imatinib versus imatinib solely for newly diagnosed chronic myeloid leukemia: a randomized phase 3 trial with 5-year outcomes.

PURPOSE: The synergistic effects of combining arsenic compounds with imatinib against chronic myeloid leukemia (CML) have been established using in vitro data. We conducted a clinical trial to compare the efficacy of the arsenic realgar-indigo naturalis formula (RIF) plus imatinib with that of imatinib monotherapy in patients with newly diagnosed chronic phase CML (CP-CML). METHODS: In this multicenter, randomized, double-blind, phase 3 trial, 191 outpatients with newly diagnosed CP-CML were randomly assigned to receive oral RIF plus imatinib (n = 96) or placebo plus imatinib (n = 95). The primary end point was the major molecular response (MMR) at 6 months. Secondary end points include molecular response 4 (MR4), molecular response 4.5 (MR4.5), progression-free survival (PFS), overall survival (OS), and adverse events. RESULTS: The median follow-up duration was 51 months. Due to the COVID-19 pandemic, the recruitment to this study had to be terminated early, on May 28, 2020. The rates of MMR had no significant statistical difference between combination and imatinib arms at 6 months and any other time during the trial. MR4 rates were similar in both arms. However, the 12-month cumulative rates of MR4.5 in the combination and imatinib arms were 20.8% and 10.5%, respectively (p = 0.043). In core treatment since the 2-year analysis, the frequency of MR4.5 was 55.6% in the combination arm and 38.6% in the imatinib arm (p = 0.063). PFS and OS were similar at five years. The safety profiles were similar and serious adverse events were uncommon in both groups. CONCLUSION: The results of imatinib plus RIF as a first-line treatment of CP-CML compared with imatinib might be more effective for achieving a deeper molecular response (Chinadrugtrials number, CTR20170221).

Mesenchymal Stromal Cells Regulate M1/M2 Macrophage Polarization in Mice with Immune Thrombocytopenia.

Mesenchymal stromal cells have shown promising effects in the treatment of immune thrombocytopenia. However, the underlying mechanisms are not fully understood. In this study, we investigated the therapeutic effects of human bone marrow mesenchymal stromal cells (hBMSCs) and analyzed their unique role in regulating the M1/M2 macrophage ratio. We established a passive immune thrombocytopenia (ITP) mouse model and showed that there was a significant M1/M2 imbalance in ITP model mice by assessing the M1/M2 ratios in the liver, spleen, and bone marrow; we observed excessive activation of M1 cells and decreased M2 cell numbers in vivo. We have shown that systemic infusion of hBMSCs effectively elevated platelet levels after disease onset. Further analysis revealed that hBMSCs treatment significantly suppressed the number of proinflammatory M1 macrophages and enhanced the number of anti-inflammatory M2 macrophages; in addition, the levels of proinflammatory factors, such as interleukin-1ß (IL-1ß) and tumor necrosis factor-α (TNF-α), were significantly decreased in vivo, while the levels of the anti-inflammatory factor interleukin-10 (IL-10) were increased. In conclusion, our data suggest that hBMSCs treatment can effectively increase platelet counts, and the mechanism is related to the induction of macrophage polarization toward the anti-inflammatory M2 phenotype and the decrease in proinflammatory cytokine production, which together ameliorate innate immune disorders.

Preclinical Short-term and Long-term Safety of Human Bone Marrow Mesenchymal Stem Cells.

Mesenchymal stem cells (MSCs) have become a promising therapeutic method. More safety data are needed to support clinical studies in more diseases. The aim of this study was to investigate the short- and long-term safety of human bone marrow-derived MSCs (hBMMSCs) in mice. In the present study, we injected control (saline infusion only), low (1.0 × 106/kg), medium (1.0 × 107/kg), and high (1.0 × 108/kg) concentrations of hBMMSCs into BALB/c mice. The safety of the treatment was evaluated by observing changes in the general condition, hematology, biochemical indices, pathology of vital organs, lymphocyte subsets, and immune factor levels on days 14 and 150. In the short-term toxicity test, no significant abnormalities were observed in the hematological and biochemical parameters between the groups injected with hBMMSCs, and no significant damage was observed in the major organs, such as the liver and lung. In addition, no significant differences were observed in the toxicity-related parameters among the groups in the long-term toxicity test. Our study also demonstrates that mice infused with different doses of hBMMSCs do not show abnormal immune responses in either short-term or long-term experiments. We confirmed that hBMMSCs are safe through a 150-day study, demonstrating that this is a safe and promising therapy and offering preliminary safety evidence to promote future clinical applications of hBMMSCs in different diseases.

Increased peripapillary capillaries in patients with acute leukemia by using optical coherence tomography angiography.

PURPOSE: To evaluate the radial peripapillary capillary vessel density (RPC-VD) and thickness of the retinal nerve fiber layer (RNFL) in acute leukemia (AL) and the associations of these characteristics with blood laboratory parameters. METHODS: A cross-sectional study was performed at the Ophthalmology Department of the Sun Yat-sen Memorial Hospital from February 2019 to April 2022. Sixty eyes of 30 patients diagnosed with AL and sixty eyes of 30 matched healthy controls were included. Optical coherence tomography angiography (OCTA) in the 4.5-mm Angio Disc scan mode and the Ganglion cell complex scan mode were performed for all participants. Correlation analyses were used to examine the associations of RPC-VD and RNFL with blood laboratory parameters. RESULTS: Patients in the AL group had significantly increased RPC-VD in the whole-image (51.42±0.35 vs. 49.52±0.36) and peripapillary fields (53.90±0.43 vs. 51.17±0.50) compared with people in the control group (all P<0.001), while no difference was found for RPC-VD in the inside optic disk fields in the two groups. The RNFL in the AL group was significantly thicker than that in the control group (131.10±3.89 µm vs. 115.03±2.22 µm, P<0.05). Complete blood count (CBC) parameters, including red blood cells, hemoglobin and hematocrit, had a significant negative correlation with RPC-VD and RNFL (all P <0.05). CONCLUSION: An increased RPC-VD and a thicker RNFL are evidence of fundus changes in patients with early-stage AL, and these metrics may be related to decreases in red blood cells, hemoglobin and hematocrit.

The effect of granulocyte-colony stimulating factor, decitabine, and busulfan-cyclophosphamide versus busulfan-cyclophosphamide conditioning on relapse in patients with myelodysplastic syndrome or secondary acute myeloid leukaemia evolving from myelodysplastic syndrome undergoing allogeneic haematopoietic stem-cell transplantation: an open-label, multicentre, randomised, phase 3 trial.

BACKGROUND: Relapse remains high in patients with myelodysplastic syndrome-refractory anaemia with excess blasts (RAEB) or secondary acute myeloid leukaemia evolving from myelodysplastic syndrome undergoing allogeneic haematopoietic stem-cell transplantation (HSCT). We aimed to investigate whether granulocyte-colony stimulating factor (G-CSF) and decitabine plus busulfan-cyclophosphamide conditioning reduced relapse compared with busulfan-cyclophosphamide in this population. METHODS: We did an open-label, randomised, phase 3 trial at six hospitals in China. Eligible patients (aged 14-65 years) had myelodysplastic syndrome-RAEB or secondary acute myeloid leukaemia evolving from myelodysplastic syndrome, and an Eastern Cooperative Oncology Group performance status of 0-2 and HSCT comorbidity index of 0-2. Patients were randomly assigned (1:1) to receive G-CSF, decitabine, and busulfan-cyclophosphamide conditioning or busulfan-cyclophosphamide conditioning. Randomisation was done with permuted blocks (block size four) with no stratification and was implemented through an interactive web-based response system, which was independent of study site staff and investigators. G-CSF, decitabine, and busulfan-cyclophosphamide conditioning comprised G-CSF 5 µg/kg daily subcutaneously (days -17 to -10), decitabine 20 mg/m2 daily intravenously (days -14 to -10), busulfan 3·2 mg/kg daily intravenously (days -7 to -4), and cyclophosphamide 60 mg/kg daily intravenously (days -3 and -2). Busulfan-cyclophosphamide conditioning comprised the same dose and duration of busulfan and cyclophosphamide. The primary endpoint was 2 year cumulative incidence of relapse. All efficacy and safety endpoints were assessed in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, NCT02744742; the trial is complete. FINDINGS: Between April 18, 2016, and Sept 30, 2019, 297 patients were screened for eligibility, 202 of whom were randomly assigned to G-CSF, decitabine, and busulfan-cyclophosphamide (n=101) or busulfan-cyclophosphamide (n=101) conditioning. 123 (61%) participants were male and 79 (31%) were female. Median follow-up was 32·4 months (IQR 10·0-43·0). The 2-year cumulative incidence of relapse was 10·9% (95% CI 5·8-17·9) in the G-CSF, decitabine, and busulfan-cyclophosphamide group and 24·8% (16·8-33·5) in the busulfan-cyclophosphamide group (hazard ratio 0·39 [95% CI 0·19-0·79]; p=0·011). Within 100 days after transplantation, the most common grade 3-4 adverse events in the G-CSF, decitabine, and busulfan-cyclophosphamide group and the busulfan-cyclophosphamide group were infections (34 [34%] and 32 [32%]), acute graft-versus-host disease (30 [30%] and 30 [30%]), and gastrointestinal toxicity (28 [28%] and 29 [29%]). 11 (11%) patients in the G-CSF, decitabine, and busulfan-cyclophosphamide group and 13 (13%) in the busulfan-cyclophosphamide group died of adverse events. There were no treatment related deaths. INTERPRETATION: Our results suggest that G-CSF, decitabine, and busulfan-cyclophosphamide conditioning is a better choice than busulfan-cyclophosphamide conditioning for patients with myelodysplastic syndrome-RAEB or secondary acute myeloid leukaemia evolving from myelodysplastic syndrome undergoing allogeneic HSCT. This conditioning could be a suitable therapuetic option for this patient population. FUNDING: None. TRANSLATION: For the Chinese translation of the abstract see Supplementary Materials section.

HMGB1 is increased in patients with immune thrombocytopenia and negatively associates with Tregs.

INTRODUCTION: Refractory or recurrent immune thrombocytopenia (ITP) patients suffer from the dual threat of high mortality and drug toxicity in addition to a very poor quality of life. Previous studies have shown that high mobility group box 1 (HMGB1) can promote the development of rheumatoid arthritis, systemic lupus erythematosus, and other autoimmune diseases. However, there is still a lack of research on the role of HMGB1 in the pathogenesis of ITP and whether it can be used as a predictor of efficacy and prognosis. METHODS: 20 patients of adult ITP with splenectomy were chosen as the experimental group, while 19 adults underwent splenectomy for traumatic splenic rupture without other diseases as the control group. We measured the expression of HMGB1, RORγt and Foxp3 in spleen tissues by immunohistochemistry. Another 50 patients, of which 20 were newly diagnosed without treatment and 30 were refractory ITP, and 25 healthy controls were enrolled to analyse the expression levels and mRNA levels of HMGB1, RORγt and Foxp3 in peripheral blood by Western blot and RT-qPCR. The expression of HMGB1, IL-17 and IL-10 in serum was assayed by ELISA. PBMCs from newly diagnosed ITP patients were cultured in vitro which stimulated with recombinant humanHMGB1 (rHMGB1) and its inhibitors, in which the expressions of RORγt and Foxp3 were measured. RESULTS: The expression of HMGB1 in the spleen with refractory ITP was significantly higher, while Foxp3 was decreased. A significant negative correlation was found between HMGB1 and Foxp3, and the overexpression of HMGB1 was significantly correlated with poor efficacy after splenectomy. The expression of HMGB1 and IL-17 increased and showed a positive correlation in serum, while IL-10 decreased and was negatively correlated with HMGB1. In PBMCs, the expression of HMGB1 and RORγt increased, while Foxp3 decreased, and the differences were more obvious in the refractory chronic ITP group. In a coculture system with PBMCs of untreated ITP patients, rHMGB1 increased RORγt expression and decreased Foxp3 expression, while an antiHMGB1 antibody partially corrected the above changes. CONCLUSION: Our results suggest that HMGB1 is associated with the imbalance of Treg/Th17 cells and is involved in the pathogenesis of ITP.

Lineage switch from lymphoma to myeloid neoplasms: First case series from a single institution.

Lymphoma relapse is very common in clinical work, but lineage switch at relapse is rare. Although some cases have reported acute lymphocytic leukemia (ALL) switch to acute myeloid leukemia (AML) or myeloid sarcoma upon relapse, phenotype switch seldom occurs in other types of lymphoma. Here we report six cases with lineage switch from lymphoma to myeloid neoplasms. In our cohort, three cases were mantle cell lymphoma (MCL), and the other three cases were T-cell lymphoblastic lymphoma (T-LBL), B-cell lymphoblastic lymphoma (B-LBL), and diffuse large B-cell lymphoma (DLBCL) at the initial diagnosis. When linage switch occurred, most cases were AML M5 phenotypes, and only one case was myelodysplastic syndrome (MDS) phenotype. 11q23/mixed-lineage leukemia (MLL) rearrangement was negative in all cases. Although intensive therapy and stem cell transplantation have been applied in most cases, the poor outcome cannot be reversed. Therefore, we found that lineage switch could occur not only from ALL to AML or vice versa, but also from MCL or DLBCL to AML. Moreover, the incidence of MLL rearrangement in lineage switch is lower in adult hematologic malignancies as compared with pediatric patients.

Growth of T-cell lymphoma cells is inhibited by mPGES-1/PGE2 suppression via JAK/STAT, TGF-ß/Smad3 and PI3K/AKT signal pathways.

Background: T-cell lymphoma (TCL) has a very poor prognosis with limited treatment options and novel therapeutic target is urgently needed. Our previous studies have found that suppression of membrane-bound prostaglandin E2 synthase l/prostaglandin E2 (mPGES-1/PGE2) exerted anti-neoplastic effects in leukemia cells by suppressing AKT signal pathway. Here, we aim at evaluating the role and mechanism of mPGES-1/PGE2 signaling in TCL. Methods: Expression of mPGES-1 in TCL cell line Hut78 was analyzed by Western blot and immunofluorescence. CAY10526, a selective mPGES-1 inhibitor, was used to treat Hut 78 cells. Cell viability assays was performed by using cell counting kit-8 (CCK-8). Cell apoptosis rate was examined by flow cytometer. PGE2 synthesis was detected by enzyme immunoassay (EIA). The expression of mPGES-1, cleaved caspase-3, Janus kinase/signal transduction and transcription (JAK/STAT), transforming growth factor-ß (TGF-ß)/Smad3 and phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) signaling pathway of Hut 78 cells after exposed to CAY10526 was analyzed by Western blot. Results: mPGES-1 was highly expressed in Hut78 cell compared to normal peripheral blood mono-nuclear cells. CAY10526 inhibited cell proliferation and induced apoptosis in Hut78 cells. These effects may be partially attributed to the activation of the Caspase family and the inhibition of JAK/STAT, TGF-ß/Smad3 and PI3K/AKT signal pathways. Conclusions: Our results suggested that mPGES-1/PGE2 could be a potential therapeutic target for TCL.

The short-term predictive value of CD4+ cells for combination therapy with high-dose dexamethasone and immunoglobulin in newly diagnosed primary immune thrombocytopenia patients.

INTRODUCTION: Dexamethasone (DXM) or immunoglobulin (IVIg) are first-line therapies for primary immune thrombocytopenia (ITP), with an effective rate of 80 %. Some patients with both severe bleeding symptoms and platelet counts of <30 × 109/L received a combination of DXM and IVIg. Autoimmune disorders, especially involving CD4+ T-cells, play a key role in the pathogenesis of ITP. We assumed that variations in the immune status of CD4+ T-cells will lead to different treatment responses. Until now, there have been few relevant clinical studies on CD4+ T-cells and the outcome of first-line therapies. METHODS: A prospective study enrolling 42 newly diagnosed ITP patients and 30 normal control volunteers was performed. The profiles of major CD4+ T-cells, including T helper (Th)1, Th2, Th17, and regulatory T (Treg) cells, and the related levels of interleukin (IL)-2, IL-17, and IL-23 were examined. The platelet number was recorded at the time point of day 0, day 14, and day 30. RESULTS: Greater concentrations of Th1 and Th17 cells and lower relative numbers of Treg cells were found in the ITP group. As for the treatment outcome on day 14, the profiles of Th2 and IL-2 were significantly greater in the NR group, while the expression of IL-17 was elevated in the CR group. As for the treatment outcome on day 30, higher levels of Th2 cells were observed in those patients who needed 2× pulses of HD DXM compared to those who needed only 1× pulse of HD DXM and IVIg, and receiver operating characteristic curve analysis showed that lower Treg cell may predict favorable values. Meanwhile, the higher IL-23 value may predict a poor early response. CONCLUSIONS: Our results indicate that Th1, Th17, and Treg cells and IL-2 and IL-23 participate in the onset of ITP. Higher profiles of Th2, IL-2 and IL-23 may predict poor treatment outcomes. Higher levels of IL-17 and lower profile of Treg may predict sensitivity to HD DXM and IVIg combination therapy.

Loss of PRMT7 reprograms glycine metabolism to selectively eradicate leukemia stem cells in CML.

Our group has reported previously on the role of various members of the protein arginine methyltransferase (PRMT) family, which are involved in epigenetic regulation, in the progression of leukemia. Here, we explored the role of PRMT7, given its unique function within the PRMT family, in the maintenance of leukemia stem cells (LSCs) in chronic myeloid leukemia (CML). Genetic loss of Prmt7, and the development and testing of a small-molecule specific inhibitor of PRMT7, showed that targeting PRMT7 delayed leukemia development and impaired self-renewal of LSCs in a CML mouse model and in primary CML CD34+ cells from humans without affecting normal hematopoiesis. Mechanistically, loss of PRMT7 resulted in reduced expressions of glycine decarboxylase, leading to the reprograming of glycine metabolism to generate methylglyoxal, which is detrimental to LSCs. These findings link histone arginine methylation with glycine metabolism, while suggesting PRMT7 as a potential therapeutic target for the eradication of LSCs in CML.