Combined inhibition of XIAP and autophagy induces apoptosis and differentiation in acute myeloid leukaemia.

Perturbations in autophagy, apoptosis and differentiation have greatly affected the progression and therapy of acute myeloid leukaemia (AML). The role of X-linked inhibitor of apoptosis (XIAP)-related autophagy remains unclear in AML therapeutics. Here, we found that XIAP was highly expressed and associated with poor overall survival in patients with AML. Furthermore, pharmacologic inhibition of XIAP using birinapant or XIAP knockdown via siRNA impaired the proliferation and clonogenic capacity by inducing autophagy and apoptosis in AML cells. Intriguingly, birinapant-induced cell death was aggravated in combination with ATG5 siRNA or an autophagy inhibitor spautin-1, suggesting that autophagy may be a pro-survival signalling. Spautin-1 further enhanced the ROS level and myeloid differentiation in THP-1 cells treated with birinapant. The mechanism analysis showed that XIAP interacted with MDM2 and p53, and XIAP inhibition notably downregulated p53, substantially increased the AMPKα1 phosphorylation and downregulated the mTOR phosphorylation. Combined treatment using birinapant and chloroquine significantly retarded AML progression in both a subcutaneous xenograft model injected with HEL cells and an orthotopic xenograft model injected intravenously with C1498 cells. Collectively, our data suggested that XIAP inhibition can induce autophagy, apoptosis and differentiation, and combined inhibition of XIAP and autophagy may be a promising therapeutic strategy for AML.

MicroRNA-143 acts as a tumor suppressor through Musashi-2/DLL1/Notch1 and Musashi-2/Snail1/MMPs axes in acute myeloid leukemia.

BACKGROUND: The previous studies have revealed that abnormal RNA-binding protein Musashi-2 (MSI2) expression is associated with cancer progression through post-transcriptional mechanisms, however mechanistic details of this regulation in acute myeloid leukemia (AML) still remain unclear. Our study aimed to explore the relationship between microRNA-143 (miR-143) and MSI2 and to clarify their clinical significance, biological function and mechanism. METHODS: Abnormal expression of miR-143 and MSI2 were evaluated in bone marrow samples from AML patients by quantitative real time-PCR. Effects of miR-143 on regulating MSI2 expression were investigated using luciferase reporter assay. Functional roles of MSI2 and miR-143 on AML cell proliferation and migration were determined by CCK-8 assay, colony formation, and transwell assays in vitro and in mouse subcutaneous xenograft and orthotopic transplantation models in vivo. RNA immunoprecipitation, RNA stability measurement and Western blotting were performed to assess the effects of MSI2 on AML. RESULTS: We found that MSI2 was significantly overexpressed in AML and exerted its role of promoting AML cell growth by targeting DLL1 and thereby activating Notch signaling pathway. Moreover, we found that MSI2 bound to Snail1 transcript and inhibited its degradation, which in turn upregulated the expression of matrix metalloproteinases. We also found that MSI2 targeting miR-143 is downregulated in AML. In the AML xenograft mouse model, overexpression of MSI2 recapitulated its leukemia-promoting effects, and overexpression of miR-143 partially attenuated tumor growth and prevented metastasis. Notably, low expression of miR-143, and high expression of MSI2 were associated with poor prognosis in AML patients. CONCLUSIONS: Our data demonstrate that MSI2 exerts its malignant properties via DLL1/Notch1 cascade and the Snail1/MMPs axes in AML, and upregulation of miR-143 may be a potential therapeutic approach for AML.

Benzene induces haematotoxicity by promoting deacetylation and autophagy.

Chronic exposure to benzene is known to be associated with haematotoxicity and the development of aplastic anaemia and leukaemia. However, the mechanism underlying benzene-induced haematotoxicity, especially at low concentrations of chronic benzene exposure has not been well-elucidated. Here, we found that increased autophagy and decreased acetylation occurred in bone marrow mononuclear cells (BMMNCs) isolated from patients with chronic benzene exposure. We further showed in vitro that benzene metabolite, hydroquinone (HQ) could directly induce autophagy without apoptosis in BMMNCs and CD34+ cells. This was mediated by reduction in acetylation of autophagy components through inhibiting the activity of acetyltransferase, p300. Furthermore, elevation of p300 expression by Momordica Antiviral Protein 30 Kd (MAP30) or chloroquine reduced HQ-induced autophagy. We further demonstrated that in vivo, MAP30 and chloroquine reversed benzene-induced autophagy and haematotoxicity in a mouse model. Taken together, these findings highlight increased autophagy as a novel mechanism for benzene-induced haematotoxicity and provide potential strategies to reverse this process for therapeutic benefits.

Inhibition of autophagy enhances the antitumour activity of tigecycline in multiple myeloma.

Accumulating evidence shows that tigecycline, a first-in-class glycylcycline, has potential antitumour properties. Here, we found that tigecycline dramatically inhibited the proliferation of multiple myeloma (MM) cell lines RPMI-8226, NCI-H929 and U266 in a dose and time-dependent manner. Meanwhile, tigecycline also potently impaired the colony formation of these three cell lines. Mechanism analysis found that tigecycline led to cell cycle arrest at G0/G1 with down-regulation of p21, CDK2 and cyclin D1, rather than induced apoptosis, in MM cells. Importantly, we found that tigecycline induced autophagy and an autophagy inhibitor bafilomycin A1 further amplified the tigecycline-induced cytotoxicity, suggesting that autophagy plays a cytoprotective role in tigecycline-treated MM cells. Mechanisms modulating autophagy found that tigecycline enhanced the phosphorylation of AMPK, but did not decrease the phosphorylation of Akt, to inhibit the phosphorylation of mTOR and its two downstream effectors p70S6K1 and 4E-BP1. Tigecycline effectively inhibited tumour growth in the xenograft tumour model of RPMI-8226 cells. Autophagy also occurred in tigecycline-treated tumour xenograft, and autophagy inhibitor chloroquine and tigecycline had a synergistic effect against MM cells in vivo. Thus, our results suggest that tigecycline may be a promising candidate in the treatment of MM.

Matrine induces Akt/mTOR signalling inhibition-mediated autophagy and apoptosis in acute myeloid leukaemia cells.

Pharmacological modulation of autophagy has been referred to as a promising therapeutic strategy for cancer. Matrine, a main alkaloid extracted from Sophora flavescens Ait, has antitumour activity against acute myelocytic leukaemia (AML). Whether autophagy is involved in antileukaemia activity of matrine remains unobvious. In this study, we demonstrated that matrine inhibited cell viability and colony formation via inducing apoptosis and autophagy in AML cell lines HL-60, THP-1 and C1498 as well as primary AML cells. Matrine promoted caspase-3 and PARP cleavage dose-dependently. Matrine up-regulated the level of LC3-II and down-regulated the level of SQSTM1/p62 in a dose-dependent way, indicating that autophagy should be implicated in anti-AML effect of matrine. Furthermore, the autophagy inhibitor bafilomycin A1 relieved the cytotoxicity of matrine by blocking the autophagic flux, while the autophagy promoter rapamycin enhanced the cytotoxicity of matrine. Additionally, matrine inhibited the phosphorylation of Akt, mTOR and their downstream substrates p70S6K and 4EBP1, which led to the occurrence of autophagy. In vivo study demonstrated that autophagy was involved in antileukaemia effect of matrine in C57BL/6 mice bearing murine AML cell line C1498, and the survival curves showed that mice did benefit from treatment with matrine. Collectively, our findings indicate that matrine exerts antitumour effect through apoptosis and autophagy, and the latter one might be a potential therapeutic strategy for AML.

Increased Th17 cells and IL-17A exist in patients with B cell acute lymphoblastic leukemia and promote proliferation and resistance to daunorubicin through activation of Akt signaling.

BACKGROUND: Immune regulation is crucial for the pathogenesis of B-cell acute lymphoblastic leukemia (B-ALL). It has been reported that Th17 cells as a newly identified subset of CD4(+) T cells are involved in the pathogenesis of several hematological disorders. However, the role of Th17 cells in the pathophysiology of B-ALL is still unclear. METHODS: The frequencies of T cells were determined by flow cytometry in the peripheral blood and bone marrow of 44 newly diagnosed B-ALL patients and 25 age-matched healthy donors. The cell viability and apoptosis were determined by CCK-8 assay and Annexin V staining, respectively. Western blot was applied to identify the level of Akt and Stat3 phosphorylation. RESULTS: We assessed and observed a significantly increased frequency of Th17 cells and a drastically decreased frequency of Th1 cells in peripheral blood mononuclear cells and bone marrow mononuclear cells from newly diagnosed B-ALL patients compared with healthy donors. Furthermore, increased levels of Th17-related cytokines including IL-17, IL-21, IL-23, IL-1ß, and IL-6 were presented in between blood and marrow in B-ALL patients. Both IL-17A and IL-21, two Th17-secreted cytokines, induced the proliferation of B-ALL cell line Nalm-6 and patient B-ALL cells isolated from B-ALL patients, herein either cytokine led to the phosphorylation of Akt and Stat3. Additionally, IL-17A promoted resistance to daunorubicin via activation of Akt signaling and the PI3K/Akt inhibitor LY294002 or perifosine almost completely rescued daunorubicin-induced cell death in B-ALL cells. CONCLUSIONS: Our findings suggest that elevated Th17 cells secrete IL-17A by which promotes the proliferation and resistance to daunorubicin in B-ALL cells through activation of Akt signaling. Th17 cells may represent a novel target to improve B-ALL immunotherapy.

Th17 cells and interleukin-17 increase with poor prognosis in patients with acute myeloid leukemia.

Although Th17 cells play crucial roles in the pathogenesis of many autoimmune and inflammatory disorders, their roles in malignancies are currently under debate. The role and mechanism of Th17 cells in patients with acute myeloid leukemia (AML) remain poorly understood. Here we demonstrated that the frequency of Th17 cells was significantly increased in peripheral blood mononuclear cells (PBMCs) and bone marrow mononuclear cells from AML patients compared with healthy donors. Plasma levels of interleukin (IL)-17, IL-22, IL-23, IL-1ß, IL-6, and transforming growth factor (TGF)-ß1 were significantly increased in blood and bone marrow in AML patients compared with healthy donors. The in vitro experiments demonstrated that IL-1ß, IL-6, IL-23, but not TGF-ß1 promoted the generation and differentiation of Th17 cells from naive CD4(+) T cells in humans. IL-17A, a signature cytokine secreted by Th17 cells, induced the proliferation of IL-17 receptor (IL-17R)-positive AML cells via IL-17R, in which activation of PI3K/Akt and Jak/Stat3 signaling pathway may play important roles. In addition, combination of IL-17A and IL-22 significantly reduced the generation of Th1 cells and the production of interferon (IFN)-γ from healthy donor or AML patient peripheral blood mononuclear cells. Patients with high Th17 cell frequency had poor prognosis, whereas patients with high Th1 cell frequency had prolonged survival. Combined analysis of Th1 and Th17 cell frequencies improved the ability to predict patient outcomes. In conclusion, Th17 cells play a crucial role in the pathogenesis of AML and may be an important therapeutic target and prognostic predictor.

Randomized trial of autologous bone marrow mesenchymal stem cells transplantation for hepatitis B virus cirrhosis: regulation of Treg/Th17 cells.

BACKGROUND AND AIM: Liver cirrhosis is one of the major consequences of hepatitis B virus (HBV) infection, and transplantation of autologous bone marrow mesenchymal stem cells (ABMSCs) is one of promising therapies for patients with HBV-related liver cirrhosis (HBV-LC). However, the mechanism is unclear. The aim of the current study was to explore the role of Treg/Th17 cells in ABMSCs transplantation in patients with HBV-LC. METHODS: In this prospective study, 56 patients were enrolled and randomly assigned to transplantation group and control group. After 24-week follow-up, 39 patients completed the study (20 cases in transplantation group and 19 cases in control group). The Model for End-Stage Liver Disease scores, liver function, changes of Treg/Th17 cells, as well as related transcription factors and serum cytokines, were determined. RESULTS: Although patients in both groups showed significant improvement after Entecavir treatment, ABMSC transplantation further improved patients' liver function. Moreover, there was a significant increase in Treg cells and a marked decrease in Th17 cells in the transplantation group compared with control, leading to an increased Treg/Th17 ratio. Furthermore, mRNA levels of Treg-related transcription factor (Foxp3) and Th17-related transcription factor (RORγt) were increased and decreased, respectively. In addition, serum transforming growth factor-ß levels were significantly higher at early weeks of transplantation, while serum levels of interleukin-17, tumor necrosis factor-α, and interleukin-6 were significantly lower in patients in the transplantation group compared with control. CONCLUSION: ABMSCs transplantation was effective in improving liver function in patients with HBV-LC, which was mediated, at least in part, through the regulation of Treg/Th17 cell balance.

CD44: a cancer stem cell marker and therapeutic target in leukemia treatment.

CD44 is a ubiquitous leukocyte adhesion molecule involved in cell-cell interaction, cell adhesion, migration, homing and differentiation. CD44 can mediate the interaction between leukemic stem cells and the surrounding extracellular matrix, thereby inducing a cascade of signaling pathways to regulate their various behaviors. In this review, we focus on the impact of CD44s/CD44v as biomarkers in leukemia development and discuss the current research and prospects for CD44-related interventions in clinical application.

Matrine induces autophagic cell death by triggering ROS/AMPK/mTOR axis and apoptosis in multiple myeloma.

Despite significant advancements in multiple myeloma (MM) treatment in recent years, most patients will eventually develop resistance or experience relapse. Matrine, a primary active compound of traditional Chinese medicinal herb Sophora flavescens Ait, has been found to have anti-tumor properties in various types of malignant tumors. Whether autophagy plays a crucial role in the anti-MM effect of matrine remain unknown. Herein, we found that matrine could trigger apoptosis and cell cycle arrest, and meanwhile induce autophagy in MM cells in vitro. We further ascertained the role of autophagy by using ATG5 siRNA or the autophagy inhibitor spautin-1, which partially reversed matrine's inhibitory effect on MM cells. Conversely, the combination of matrine with the autophagy inducer rapamycin enhanced their anti-tumor activity. These findings suggest that autophagy induced by matrine can lead to cell death in MM cells. Further mechanism investigation revealed that matrine treatment increased the levels of reactive oxygen species (ROS) and AMPKα1 phosphorylation and decreased the phosphorylation of mTOR in MM cells. Additionally, co-treatment with AMPKα1 siRNA or the ROS scavenger N-acetyl-1-cysteine weakened the increase in autophagy that was induced by matrine. Finally, we demonstrated a synergistic inhibitory effect of matrine and rapamycin against MM in a xenograft mouse model. Collectively, our findings provided novel insights into the anti-MM efficacy of matrine and suggest that matrine induces autophagy by triggering ROS/AMPK/mTOR axis in MM cells, and combinatorial treatment of matrine and rapamycin may be a promising therapeutic strategy against MM.

Increase of CD3+CD7- T cells in bone marrow predicts invasion in patients with T-cell non-Hodgkin's lymphoma.

Background: The T-cell non-Hodgkin's lymphoma (T-NHL) patients with bone marrow (BM) invasion have a poor prognosis. Although BM biopsy is still a confirmed diagnosis method, the low sensitivity restricts its use to detect the minimal BM invasion. It is of great clinical significance to establish a rapid and highly sensitive method to evaluate BM invasion. Methods: We conducted a retrospective study of 85 patients with new diagnosed T-NHL patients enrolled in our institute. The bone marrow mononuclear cells (BMMNCs) cells were isolated, stained with different combinations of antibody and subjected to flow cytometry analysis. Results: We found that CD3+CD7- T cells increased significantly in the BM in T-NHL patients with BM invasion. The patients were divided into the low and high groups according to the cutoff value of 1.035% obtained by analyzing the receiver operating characteristic (ROC) curve of the percentage of CD3+CD7- T cells of nucleated cells at diagnosis. The ratio of invasion in high group was markedly higher than that in low group. Furthermore, CD3+CD7- T cells presented significantly higher level of programmed cell death-1 (PD-1), lymphocyte-activation-gene-3 (LAG3) and CD4/CD8 ratio. Conclusions: Our study revealed the percentage of CD3+CD7- T cells of nucleated cells in BM was a potential diagnostic predictor of BM invasion with T-NHL.

Lentivirus-mediated overexpression of TGF-ß inducible early gene 1 inhibits SW1990 pancreatic cancer cell growth.

TIEG1 (TGF-ß inducible early gene 1) plays a significant role in regulating cell proliferation and apoptosis in various cell types. Previous studies have shown a close relationship between the expression level of TIEG1 and various cancers, including breast, prostate, colorectal and pancreatic cancer. In this study, we up-regulated the gene expression of TIEG1 in SW1990 pancreatic cancer cell line by a lentivirus transfection system and investigated its potential as a therapeutic target for pancreatic cancer. The results showed that lentivirus-mediated overexpression of TIEG1 gene inhibited human pancreatic cancer SW1990 cell proliferation and caused the cell cycle arrest at the G1-phase in vitro. SW1990 cells transduced with lenti-TIEG1 showed significant inhibition of colony formation and cancer cell growth in 3-D culture model. Moreover, overexpression of TIEG1 gene significantly slowed the growth of SW1990 xenografts in nude mice. Taken together, these data provided evidence that overexpression of TIEG1 gene by a lentivirus transfection system led to suppressed human pancreatic cancer cell growth and might therefore be a feasible approach in the clinical management of pancreatic cancer.

PD-L1 Is Expressed and Promotes the Expansion of Regulatory T Cells in Acute Myeloid Leukemia.

Intratumoral accumulation of CD4+CD25+Foxp3+ regulatory T (Treg) cells occurs in acute myeloid leukemia (AML), but little is known about the role of tumor cells themselves in this process. Here, we showed that an immune checkpoint PD-L1 expressed by AML cells promoted the conversion and expansion of Treg cells sustaining high expression of Foxp3 and PD-1 as well as a suppressive function. Furthermore, an AML cell line HEL overexpressed PD-L1 promoted the conversion and expansion of Treg cells and CD4+PD-1+Foxp3+ T (PD-1+Treg) cells from the conventional CD4+ T cells. CD4+CD25highPD-1+ T cells secreted more IL-10 production than CD4+CD25highPD-1- T cells. IL-35, another cytokine secreted by Treg cells, promoted the proliferation of HL-60 cells and enhanced chemoresistance to cytarabine. Blockade of PD-1 signaling using anti-PD-L1 antibody dramatically impaired the generation of Treg cells and sharply retarded the progression of a murine AML model injected with C1498 cells. The frequency of intratumoral PD-1+ Treg cells was capable of predicting patient survival in patients with AML. In conclusion, our data suggest that PD-L1 expression by AML cells may directly drive Treg cell expansion as a mechanism of immune evasion and the frequency of PD-1+ Treg cells is a potential prognostic predictor in patients with AML.

[Protective effects of inhibition of tissue nitric oxide in the initial stage against tardive injury of testicular spermatogenic function: experiment with rats].

OBJECTIVE: To study the protective effects of inhibition of tissue nitric oxide in the initial stage against the tardive injury of contralateral testicular spermatogenic function after unilateral testicular torsion. METHODS: 56 prepubertal Sprague-Dawley rats were randomly divided into 4 equal groups: placebo group undergoing rotation of left testis 720 degrees clockwise for 4 h, fixing thereof to the scrotum, and then intravenous injection of normal saline; cyclosporine group, undergoing intraperitoneal injection of cyclosporine once daily for 1 month after the testicular rotation and fixation; NG-methyl L-arginine (L-NMMA) group, undergoing intravenous injection of L-NMMA 30 mg/kg 30 min before the testicular rotation; and sham-operation group, undergoing isolation and suture of testis only. The right (untwisted) testes were removed from 7 rats from each group 1 week and 2 months after surgery. The malondialdehyde (MDA) level and nitrous oxide (NO)/nitrogen oxide synthase (NOS) content were evaluated. Histological examination was conducted. The mean seminiferous tubule diameter (MSTD) was assessed. The level of MHC peptide-tetramer complex was determined by flow cytometry. RESULTS: The levels of MDA, NO, NOS, and MHC peptide-tetramer complex of the L-NMMA, placebo, and cyclosporine groups one week after surgery were all significantly higher than those of the sham operation group (all P < 0.05). The levels of MDA, NO, NOS, and MHC peptide-tetramer complex of the L-NMMA group were all significantly lower then those of the placebo group (all P < 0.05). The pathological damage of the contralateral testis in early and late stages in the L-NMMA group was lighter than in the placebo group. CONCLUSION: By inhibiting tissue NO production in focal organizations during the early period, L-NMMA reduces the damages inthe testis contralateral to the testis undergoing unilateral torsion.

Acute Myeloid Leukemia Cells Express ICOS Ligand to Promote the Expansion of Regulatory T Cells.

CD4+CD25+Foxp3+ regulatory T cells (Tregs) accumulate in bone marrow microenvironment in acute myeloid leukemia (AML). However, little is known about how the tumor environment including tumor cells themselves affects this process. Here we demonstrated that AML cells expressed inducible T-cell costimulator ligand (ICOSL) that can provide costimulation through ICOS for the conversion and expansion of Tregs sustaining high Foxp3 and CD25 expression as well as a suppressive function. TNF-a stimulation up-regulated the expression of ICOSL. Furthermore, both the conversion and expansion of CD4+CD25+Foxp3+ T cells and CD4+ICOS+Foxp3+ T cells were induced by co-culture with AML cells overexpressed ICOSL. CD4+CD25+ICOS+ T cells possessed stronger ability to secrete IL-10 than CD4+CD25+ICOS- T cells. The mechanism by which IL-10 promoted the proliferation of AML cells was dependent on the activation of the Akt, Erk1/2, p38, and Stat3 signaling pathways. Blockade of ICOS signaling using anti-ICOSL antibody impaired the generation of Tregs and retarded the progression of an AML mice model injected with C1498 cells. The expression of ICOSL of patient AML cells and ICOS+ Tregs were found to be predictors for overall survival and disease-free survival in patients with AML, with ICOS+ Treg cell subset being a stronger predictor than total Tregs. These results suggest that ICOSL expression by AML cells may directly drive Treg expansion as a mechanism of immune evasion and ICOS+ Treg cell frequency is a better prognostic predictor in patients with AML.

Benzene metabolite hydroquinone induces apoptosis of bone marrow mononuclear cells through inhibition of ß-catenin signaling.

The Akt/glycogen synthase kinase-3ß (GSK-3ß)/ß-catenin signaling pathway has been shown to play an important role in hematopoiesis, and hematopoietic cells are sensitive targets for benzene-induced hematotoxicity. We therefore hypothesized that dysregulation of the Akt/GSK-3ß/ß-catenin signaling was associated with benzene-induced hematotoxicity. Here, we showed that hydroquinone (HQ), a major metabolite of benzene in humans, significantly inhibited cell viability and colony formation while inducing apoptosis of human bone marrow mononuclear cells in vitro. Interestingly, we found that HQ inhibited the Akt affected ß-catenin signaling by activation of GSK-3ß, resulting in downregulation of ß-catenin and its targets Cyclin D1 and Survivin. HQ blocked nuclear translocation of ß-catenin and lymphoid enhancer-binding factor 1 (LEF-1), and importantly, HQ also reduced the interaction of ß-catenin and LEF-1 in the nucleus. As expected, blockage of GSK-3ß activity with a GSK-3ß inhibitor lithium chloride (LiCl) or activation of Akt signaling with an Akt agonist insulin-like growth factor-1 (IGF-1) could inhibit HQ-induced activation of GSK-3ß as well as hematotoxicity. Taken together, our results suggest that HQ-induced hematotoxicity in bone marrow mononuclear cells is associated with dysregulation of Akt/GSK-3ß/ß-catenin signaling due to the dissociation of ß-catenin/LEF-1 complex, and LiCl and IGF-1 may be two potential agents to ameliorate HQ-induced hematotoxicity.

Pretreatment platelet count predicts survival outcome of patients with de novo non-M3 acute myeloid leukemia.

BACKGROUND: Pretreatment platelet count has been reported as a potential tool to predict survival outcome in several solid tumors. However, the predictive value of pretreatment platelet count remains obscure in de novo acute myeloid leukemia (AML) excluding acute promyelocytic leukemia (M3). METHODS: We conducted a retrospective review of 209 patients with de novo non-M3 AML in our institute over a period of 8 years (2007-2015). Receiver operating characteristic (ROC) curve analysis was used to determine the optimal platelet (PLT) cutoff in patients. We analyzed the overall survival (OS) and disease free survival (DFS) using the log-rank test and Cox regression analysis. RESULTS: By defining the platelet count 50 × 109/L and 120 × 109/L as two cut-off points, we categorized the patients into three groups: low (<50 × 109/L), medium (50-120 × 109/L) and high (>120 × 109/L). On univariate analysis, patients with medium platelet count had longer OS and DFS than those with low or high platelet count. However, the multivariate analysis showed that only longer DFS was observed in patients with medium platelet count than those with low or high platelet count. CONCLUSION: Our findings indicate that pretreatment platelet count has a predictive value for the prognosis of patients with non-M3 AML.

Inhibition of mitochondria responsible for the anti-apoptotic effects of melatonin during ischemia-reperfusion.

OBJECTIVE: To investigate a possible mechanism responsible for anti-apoptotic effects of melatonin and provide theoretical evidences for clinical therapy. METHODS: Ischemia-reperfusion mediated neuronal cell injury model was constructed in cerebellar granule neurons (CGNs) by deprivation of glucose, serum and oxygen in media. After ischemia, melatonin was added to the test groups to reach differential concentration during reperfusion. DNA fragmentation, mitochondrial transmembrane potential, mitochondrial cytochrome c release and caspase-3 activity were observed after subjecting cerebellar granule neurons to oxygen-glucose deprivation (OGD). RESULTS: The results showed that OGD induced typical cell apoptosis change, DNA ladder and apoptosis-related alterations in mitochondrial functions including depression of mitochondrial transmembrane potential (its maximal protection ratio was 73.26%) and release of cytochrome c (its maximal inhibition ratio was 42.52%) and the subsequent activation of caspase-3 (its maximal protection ratio was 59.32%) in cytoplasm. Melatonin reduced DNA damage and inhibited release of mitochondrial cytochrome c and activation of caspase-3. Melatonin can strongly prevent the OGD-induced loss of the mitochondria membrane potential. CONCLUSION: Our findings suggested that the direct inhibition of mitochondrial pathway might essentially contribute to its anti-apoptotic effects in neuronal ischemia-reperfusion.

MAP30 inhibits autophagy through enhancing acetyltransferase p300 and induces apoptosis in acute myeloid leukemia cells.

Momordica anti-human immunodeficiency virus protein of 30 kDa (MAP30) has been shown to exhibit potent antitumor activities against several solid tumors. In the present investigation we demonstrated that MAP30 significantly inhibited the proliferation of acute myeloid leukemia (AML) HL-60 and THP-1 cell lines and patient AML cells through autophagy inhibition and apoptosis induction. Intriguingly, MAP30-induced cell death and apoptosis were partially rescued in combination with an autophagy activator rapamycin, and aggravated in combination with an autophagy inhibitor bafilomycin A1 in HL-60 cells, suggesting that autophagy is a pro-survival signal and its inhibition contributes to the induction of apoptosis in MAP30­induced cell death. Further mechanism analysis demonstrated that MAP30 enhanced p300, and C646, a selective inhibitor of p300, markedly promoted autophagy and partially rescued the MAP30-induced cell death in HL-60 cells and patient AML cells. Collectively, our findings suggest that apoptosis and autophagy act cooperatively to elicit MAP30-induced cell death and MAP30 may be a potential antitumor drug candidate against AML.