Zhihong Zheng

Down-regulation of the PI3K/Akt signaling pathway and induction of apoptosis in CA46 Burkitt lymphoma cells by baicalin

BackgroundBaicalin, a flavone present in Scutellaria baicalensis Georgi, inhibits the growth of human leukemia and myeloma cells through induction of apoptosis.MethodsThe present study was undertaken to ascertain whether cultured Burkitt lymphoma cells undergo apoptosis when treated with baicalin. Growth rates were measured using MTT and colony formation assays, and induction of apoptosis was quantified using Annexin V and DNA fragmentation assays. Mechanisms underlying observed growth suppression were examined using Western blotting.ResultsTreatment of CA46 Burkitt lymphoma cells with baicalin for 48 h markedly decreased the rate of cell proliferation; an IC50 value of 10 μM was obtained. Colony formation was almost fully suppressed at 10 μM baicalin. CA46 cells underwent apoptosis in response to baicalin treatment as evidenced by an increase in the percentage of cells stainable with Annexin V, by increased DNA fragmentation, and by activation of the intrinsic (mitochondrial) pathway for cell death as characterized by increased expression of the cleaved forms of caspase-9, caspase-3, and poly (ADP-ribose) polymerase. Additionally, baicalin was found to down-regulate anti-apoptotic and up-regulate apoptotic components of the phosphatidylinositide-3-kinase (PI3K)/serine/threonine kinase (Akt) signaling pathway.ConclusionsThe concentrations at which baicalin altered expression of components of the PI3K/Akt pathway in CA46 cells were comparable to those that suppressed growth and induced apoptosis, supporting the hypothesis that the observed growth-inhibitory and apoptosis-inducing actions of baicalin in these cells are mediated by down-regulation of this pathway.

Emodin enhances ATRA-induced differentiation and induces apoptosis in acute myeloid leukemia cells

Emodin, an extracted natural compound from the root and rhizome of Rheum palmatum L, has been shown to have multiple biological activities including anticancer functions in previous studies. In this study, we investigated the anti-leukemic activity of emodin alone or emodin in the presence all-trans retinoic acid (ATRA) in acute myeloid leukemia (AML) cells and the potential signaling pathway involved. We demonstrated that emodin could significantly enhance the sensitivity to ATRA and present additive differentiation-inducing effects in AML cell line NB4 cells and, especially, in NB4-derived ATRA-resistant MR2 cells. Further study showed that increasing dose of emodin could effectively induce growth inhibition and apoptotic effects in both cell lines as well as in primary leukemic cells from AML patients. Moreover, the apoptotic induction in AML cells was associated with the activation of caspase cascades involving caspase-9, caspase-3, and poly(ADP-ribose) polymerase (PARP) cleavage. In addition, leukemic cell response to emodin stimuli in vitro was observed through the decreased expression levels of Bcl-2 and retinoic acid receptor α (RARα). Importantly, emodin was demonstrated as a new inhibitor of PI3K/Akt in AML cells, even in primary AML cells. It inhibited Akt phosphoration (p-Akt) at Ser473 as efficiently as mTOR at Ser2448. Consistently, it exerted suppression effects on the phosphoration of mTOR downstream targets, 4E-BP1 and p70S6K. Taken together, these findings indicate that emodin might be developed as a promising anti-leukemic agent to improve the patient outcome in AML.

Clarifying the molecular mechanism associated with carfilzomib resistance in human multiple myeloma using microarray gene expression profile and genetic interaction network

Carfilzomib is a Food and Drug Administration-approved selective proteasome inhibitor for patients with multiple myeloma (MM). However, recent studies indicate that MM cells still develop resistance to carfilzomib, and the molecular mechanisms associated with carfilzomib resistance have not been studied in detail. In this study, to better understand its potential resistant effect and its underlying mechanisms in MM, microarray gene expression profile associated with carfilzomib-resistant KMS-11 and its parental cell line was downloaded from Gene Expression Omnibus database. Raw fluorescent signals were normalized and differently expressed genes were identified using Significance Analysis of Microarrays method. Genetic interaction network was expanded using String, a biomolecular interaction network JAVA platform. Meanwhile, molecular function, biological process and signaling pathway enrichment analysis were performed based on Gene Ontology and Kyoto Encyclopedia of Genes and Genomes. Totally, 27 upregulated and 36 downregulated genes were identified and a genetic interaction network associated with the resistant effect was expanded basing on String, which consisted of 100 nodes and 249 edges. In addition, signaling pathway enrichment analysis indicated that cytokine-cytokine receptor interaction, autophagy, ErbB signaling pathway, microRNAs in cancer and fatty acid metabolism pathways were aberrant in carfilzomib-resistant KMS-11 cells. Thus, in this study, we demonstrated that carfilzomib potentially conferred drug resistance to KMS-11 cells by cytokine-cytokine receptor interaction, autophagy, ErbB signaling pathway, microRNAs in cancer and fatty acid metabolism pathways, which may provide some potential molecular therapeutic targets for drug combination therapy against carfilzomib resistance.

The outcome and prognostic factors of 248 elderly patients with acute myeloid leukemia treated with standard-dose or low-intensity induction therapy.

AbstractThe prognosis of elderly patients with acute myeloid leukemia (AML) is poor, and the recommendation of standard-dose or low-intensity induction regimen for these patients remains controversial. We retrospectively analyzed treatment outcome and prognostic factors of elderly AML patients who had received either standard-dose or low-intensity induction regimens.Two hundred forty-eight elderly AML patients with good Eastern Cooperative Oncology Group performance status (ECOG PS ⩽ 2) received one of three regimens for induction in this study: standard-dose cytarabine plus idarubicin (IA; n = 144) or daunorubicin (DA; n = 42); low-intensity cytarabine, aclarubicin, and granulocyte colony-stimulating factor (G-CSF) (CAG; n = 62).After first induction treatment cycle, the overall complete remission (CR) rate was 42.7%. Patients in IA group had a higher CR rate than in DA or CAG group (49.3%, 35.7%, and 32.3%, respectively; P = 0.046). The 1-year, 3-year, and 5-year overall survival (OS) rates were 42.2%, 18.9%, and 13.5% for these 248 patients, with median survival of 9.2 months. Long-term survival of IA group was better than DA or CAG group. The 1-year, 3-year, and 5-year OS rates of IA group were 45.9%, 23.5%, and 19.4%, respectively, as compared to 39.8%, 8.3%, and estimated 2.4% in DA group, and 34.9%, 15.9%, and 6.3% in CAG group, respectively. Early induction mortality and 2-year relapse rates showed no difference among 3 groups. Univariate analysis and multivariate analysis identified lactic dehydrogenase (LDH) more than two times of upper normal limit at diagnosis and nonremission after first induction cycle as adverse prognostic factors for OS. A simple and valid scoring model was constructed for risk stratification and prediction of long-term survival of elderly AML patients.Standard-dose IA regimen could improve the prognosis of elderly AML patients with good performance status compared with standard-dose DA or low-intensity CAG regimen. All prognostic factors and risk assessment should be considered to ensure that each patient receives the suitable individualized treatment.

Synergistic Effect of Baicalin and Adriamycin in Resistant HL-60/ADM Leukaemia Cells

Background/Aims: The present study was designed to investigate the expression of multidrug resistance (MDR)-related genes, verify the synergistic effects of baicalin and Adriamycin (ADM) and investigate the related mechanisms in ADM-resistant leukaemic HL-60/ADM cells. Methods: We used a HL-60/ADM cell line. Cytotoxicity and flow cytometry assays were employed to verify the cytotoxic effects of baicalin. Real-time polymerase chain reaction and Western blotting assays were used to assess the expression of MDR-related genes and the changes in gene expression (both MDR-related and PI3K/Akt pathway-related) induced by administration of baicalin. Results: We found that only multidrug resistance protein 1 (MRP1), lung resistance-related protein (LRP) and Bcl-2 genes were expressed in both HL-60 and HL-60/ADM cells. HL-60/ADM cells exhibited significantly higher expression (p < 0.05). We also observed that low-dose baicalin (5 and 10 µmol/L) can induce growth inhibition and apoptotic effects on HL-60/ADM cells by increasing the intracellular accumulation of ADM. The synergistic effect of baicalin and ADM was verified. Concerning the potential mechanisms involved in this process, we showed that baicalin down-regulated the expression of several MDR-related and PI3K/Akt pathway-related genes. Conclusions: We confirmed the increased expression of MRP1, LRP and Bcl-2 genes in HL-60/ADM cells compared to regular HL-60 cells, which are recommended for future investigation on MDR. The present study provided evidence of the synergistic effect of baicalin and ADM in HL-60/ADM cells. Therefore, baicalin may be considered as a potential therapeutic agent against resistant leukaemia. Suppression of the PI3K/Akt signalling pathway, followed by inhibition of the expression of MDR-related genes may be a common mechanism in combination treatments with ADM for the reduction of resistance to ADM.

A 5-day cytoreductive chemotherapy followed by haplo-identical hsct (FA5-BUCY) as a tumor-ablative regimen improved the survival of patients with advanced hematological malignancies

Haplo-HSCT has been used when HLA-matched siblings are not available. Conditioning regimens aim to reduce tumor burden prior to HSCT and provide sufficient immunoablation. We report the outcome of haplo-HSCT in 63 consecutive patients from 2/2013 to 12/2015 (19 females/44 males) with high-risk or relapsed/refractory hematological malignancies (n=29-AML; 8-sAML; 19-ALL; 5-advanced-MDS; 2-CML-BC). Median age was 20 years (range: 1.1-49). Twenty-one patients achieved remission prior to transplant, while 42 did not. Patients received FA5-BUCY, i.e., 5-day salvage chemotherapy (Fludarabine/Ara-C) and conditioning (Busulfan/Cyclophosphamide). GvHD prophylaxis included ATG, CsA, MMF and short-term MTX. All patients received stem cells from bone marrow and peripheral blood, and achieved successful engraftment, except two who died before. With a median follow-up of 269 days (120-1081), 42/63 patients are still alive and disease-free. Two-year OS and RFS were similar in patients not in remission and in those in complete remission (61.3% vs 56.3%, p=0.88; 58.3% vs 56.3%, p=0.991). Non-relapse mortality and relapse incidence were 22.2% and 11.1%, respectively. Severe acute-GvHD occurred in 4/63 patients. Transplant-related mortality was low at day+100 (17.5%) and for the entire study period (20.6%). Unexpectedly, few patients experienced mild-to-moderate toxicity, and main causes of death were infection and GvHD. BM blast counts, age, and donor-recipient gender-pairs did not affect the outcome. Less chemotherapy cycles prior to HSCT might result in more favorable outcome. Thus, haplo-HSCT with FA5-BUCY appears promising for advanced disease, especially when TBI and amsacrine, used for FLAMSA, are not available and in pediatric patients for whom TBI is not recommended.

The clinical significance of Epstein-Barr virus DNA in peripheral blood mononuclear cells in patients with non-Hodgkin lymphoma.

Abstract The aim of the study was to determine the clinical significance of EBV DNA in the peripheral blood mononuclear cells (PBMCs) from the patients with non-Hodgkin lymphoma (NHL). Newly diagnosed patients with NHL were enrolled in the study (n = 328), and clinical data retrospectively analyzed. EBV DNA was detectable in 34.8% of patients, and the positivity rate was 51.6% for T/NK cell subtype and 24.3% for B cell subtype (p < .001). In diffuse large B cell lymphoma (DLBCL), extranodal NK/T-cell lymphoma, nasal type (ENKTL), peripheral T-cell lymphoma not otherwise classified (PTCL.NOS), or angioimmunoblastic T cell lymphoma (AITL), positive EBV DNA before treatment was associated with more risk factors with prognostic significance, including older age, advanced stage, extranodal involvement, bone marrow infiltration, elevated LDH, and B symptoms, and with poor prognosis.