Fumarate hydratase deficiency induces chronic myeloid leukemia progression

Background

Although tyrosine kinase inhibitors (TKIs) have profoundly improved the prognosis of chronic myeloid leukemia (CML), the mechanism of the progression to blast phase (BP) is currently unclear. Our previous study indicated that CML-BP cells utilize glycolysis to proliferate and that the fumarate level is elevated in CML-BP cells. Fumarate hydratase (FH) catalyzes fumarate to malate. A functional deficiency in FH could result in fumarate accumulation. Therefore, we wanted to determine whether an FH deficiency facilitates CML progression.

Methods

FH expression in CML chronic phase (CP) and CML-BP was analyzed. In vitro, we tested whether FH expression knockdown induces glycolysis and increases K562 cell invasiveness. DNA damage repair after FH expression knockdown was also tested.

Results

Our findings showed that CML-BP patients had lower FH expression than CML-CP patients (P=0.025). Knocking down FH expression enhanced the invasiveness of K562 cells through HIF-1α-induced glycolysis. DNA damage repair was impaired after FH expression knockdown.

Conclusions

Our findings suggested that reduced FH function may facilitate disease progression in CML through the combined effects of an elevated glycolysis level and a decreased DNA repair ability.

A network pharmacology-based study on the anti-hepatoma effect of Radix Salviae Miltiorrhizae

BACKGROUND

Radix Salviae Miltiorrhizae (RSM), a well-known traditional Chinese medicine, has been shown to inhibit tumorigenesis in various human cancers. However, the anticancer effects of RSM on human hepatocellular carcinoma (HCC) and the underlying mechanisms of action remain to be fully elucidated.

METHODS

In this study, we aimed to elucidate the underlying molecular mechanisms of RSM in the treatment of HCC using a network pharmacology approach. In vivo and in vitro experiments were also performed to validate the therapeutic effects of RSM on HCC.

RESULTS

In total, 62 active compounds from RSM and 72 HCC-related targets were identified through network pharmacological analysis. RSM was found to play a critical role in HCC via multiple targets and pathways, especially the EGFR and PI3K/AKT signaling pathways. In addition, RSM was found to suppress HCC cell proliferation, and impair cancer cell migration and invasion in vitro. Flow cytometry analysis revealed that RSM induced cell cycle G2/M arrest and apoptosis, and western blot analysis showed that RSM up-regulated the expression of BAX and down-regulated the expression of Bcl-2 in MHCC97-H and HepG2 cells. Furthermore, RSM administration down-regulated the expression of EGFR, PI3K, and p-AKT proteins, whereas the total AKT level was not altered. Finally, the results of our in vivo experiments confirmed the therapeutic effects of RSM on HCC in nude mice.

CONCLUSIONS

We provide an integrative network pharmacology approach, in combination with in vitro and in vivo experiments, to illustrate the underlying therapeutic mechanisms of RSM action on HCC.

Early recovery of the platelet count after decitabine-based induction chemotherapy is a prognostic marker of superior response in elderly patients with newly diagnosed acute myeloid leukaemia

BACKGROUND

Definite prognostic clinical factors of benefit for decitabine-based induction chemotherapy in elderly patients newly diagnosed with acute myeloid leukaemia (AML) are not identified. This study was designed to explore the potential biomarker, especially regeneration of haematopoiesis, of treatment response and survival in elderly patients with newly diagnosed AML.

METHOD

We analysed the clinical data of 117 elderly AML patients who were treated with a decitabine dose of 15 mg/m² for 5 days, granulocyte colony-stimulating factor of 300 μg/d for priming, plus cytarabine 10 mg/m² q12h for 7 days and aclarubicin 10 mg/d for 4 days (D-CAG).

RESULTS

After initial induction chemotherapy, the overall response rate and complete remission (CR) were 71.8% and 58.1%, respectively. Patients responding to the D-CAG regimen achieved higher platelet counts on day 14 after initial treatment (p < 0.001). Median counts were 59.5 × 10⁹/L in the CR group, 37 × 10⁹/L in the partial remission group and 28 × 10⁹/L in the non-responsive group. We then classified patients into those who achieved platelet counts≥60 × 10⁹/L or 100 × 10⁹/L on day 14 after D-CAG vs. those who did not. Platelet counts≥60 × 10⁹/L or 100 × 10⁹/L on day 14 were significantly associated with superior CR, overall survival and disease-free survival (80.9% vs. 45.3% p < 0.001,16.5 vs. 9.1 months p = 0.009 and 16.3 vs. 7.4 months p = 0.024; 85.2% vs. 50% p = 0.001, 31 vs. 10.1 months p = 0.003 and 16.9 vs. 8.9 months p = 0.006). Multivariate analysis confirmed that poor cytogenetics (p = 0.010) and FLT3-ITD mutation (p = 0.007) were identified as independent factors of OS, but not platelet count (p = 0.091). However, platelet count≥100 × 10⁹/L on day 14 was an independent prognostic factor of CR and DFS.

CONCLUSION

Platelet count recovery on day 14 after D-CAG induction chemotherapy is associated with response.

TRIAL REGISTRATION

D-CAG regimen was registered on ChicTR with number 11001700 .

COMPUTATIONAL EXPLORATION OF GERONTOLOGY-RELATED TOPICS SHARED ON SOCIAL MEDIA PLATFORM TWITTER

Twitter, a popular Internet social media platform, has become a significant medium for sharing information and ideas about various topics, including aging and older adults. While studies have been conducted to examine stigma or perception about specific diseases such as Alzheimer’s disease and seizure on Twitter, there has been little effort to identify general themes of Twitter posts related to aging and older adults. This exploratory study attempts to answer this need by conducting a topic analysis of posts shared on Twitter posts about aging and older adults in English. We collected 328,568 English posts from Twitter posted between 07/01/18 and 07/31/18 using 19 English keywords referring to older adults. We analyzed this whole dataset as well as a subset of posts explicitly including aging-related hashtags, such as #olderadults. We used data mining methods (including Latent Dirichlet Allocation) in computing environment MATLAB to discover topics emerging from these two sets. Among posts with explicit aging-related hashtags, the most recurrent topics were family (relation with children and grandchildren, commemoration), community (resources, looking after older adults), health (disease-specific, public health, home care, formal and informal caregivers), politics and policies (insurance/pension, new laws), and news involving older adults (e.g., crimes on/by older adults). The analysis of the larger dataset additionally uncovered posts promoting pornography featuring older females and posts sharing general Internet content featuring older adults (e.g., YouTube videos). We also share the methodological challenges we encountered and practical recommendations for gerontological researchers interested in using social media data to inform new research.

[Mean Corpuscular Volume Can Be A Predictor for Therapeutic Response of Patients with Chronic Myeloid Leukemia]

OBJECTIVE

The past studies found that the treatment of chronic myeloid leukemia (CML) with imatinib can induce the macrocytic anemia, moreover the incidence of anemia increases along with enhancement of imatinib concentration. This study was aimed to evaluate the potential relation of erythrocyte mean corpuscular volume (MCV) increase after the treatment with tyrosine kinase inhibitors (TKI) with the therapeutic response in patients with CML-chronic phase (CML-CP).

METHODS

The clinical and hematologic data including MCV, molecular and cytogenetic response of 119 patients with CML-CP were collected after treatment with TKIs, and the relation of MCV changes after treatment with the clinical characteristics and therapeutic efficacy for patients with CML-CP was analyzed.

RESULTS

The MCV in patients treated with TKIs for 12 months significantly increased as compared with that at initial diagnosis (P<0.05). The proportion of patients with increased MCV in group of complete cytogenetic response (CCyR) was significantly higher than that in group of non-CCyR (P<0.05). As compared with decreased MCV group, the patients in increased MCV group much more easily achieved CCyR after treatment for 6, 12 months (P<0.05, P<0.05) respectively, furthermore, much more easily maintained MMR (P<0.05).

CONCLUSION

The MCV as a parameter which is easily acquired may be a new marker for prodecting the therapeutic response of patients treated with TKIs.

Functional regeneration of tendons using scaffolds with physical anisotropy engineered via microarchitectural manipulation

Structural and hierarchical anisotropy underlies the structure-function relationship of most living tissues. Attempts to exploit the interplay between cells and their immediate environment have rarely featured macroscale, three-dimensional constructs required for clinical applications. Furthermore, compromises to biomechanical robustness during fabrication often limit the scaffold's relevance in translational medicine. We report a polymeric three-dimensional scaffold with tendon-like mechanical properties and controlled anisotropic microstructures. The scaffold was composed of two distinct portions, which enabled high porosity while retaining tendon-like mechanical properties. When tenocytes were cultured in vitro on the scaffold, phenotypic markers of tenogenesis such as type-I collagen, decorin, and tenascin were significantly expressed over nonanisotropic controls. Moreover, highly aligned intracellular cytoskeletal network and high nuclear alignment efficiencies were observed, suggesting that microstructural anisotropy might play the epigenetic role of mechanotransduction. When implanted in an in vivo micropig model, a neotissue that formed over the scaffold resembled native tendon tissue in composition and structure.

Effects of chidamide and its combination with decitabine on proliferation and apoptosis of leukemia cell lines

Chidamide, a novel histone deacetylase inhibitor (HDACI), shows anticancer ability against leukemia and solid tumors. Decitabine (5-Aza-2'-deoxycytidine, DAC), an anti-leukemic drug, is effective in treating acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). In our study, we investigated the anti-leukemic ability of chidamide, as well as its combination with decitabine in leukemia cells (HL60 and NB4). The results showed that the inhibitive effect of chidamide was dose- and time-dependent at concentration of 0.25-8 μM. The proliferation of HL60 and NB4 cells were significantly inhibited by chidamide or its combination with decitabine. The combination had a remarkable synergistic anti-leukemic effect. Chidamide increased the levels of acetylated histone H3 in both HL60 and NB4 cells by effectively inhibiting histone deacetylases (HDAC) enzymatic activities. The cells were blocked in G₀/G₁ phase by chidamide, but when chidamide was combined with decitabine, the cell cycle was mainly blocked in G₂/M phase, accompanied by the induction of p21 expression. In both cases (chidamide or chidamide combined with decitabine), apoptosis of tumor cells was induced through up-regulation of Bax and Caspase-3, and down-regulation of Bcl-2, showing a synergistic cytotoxicity. In conclusion, our results suggested that chidamide in combination with decitabine might be an effective therapy for AML.

High-quality thulium iron garnet films with tunable perpendicular magnetic anisotropy by off-axis sputtering - correlation between magnetic properties and film strain

Thulium iron garnet (TmIG) films with perpendicular magnetic anisotropy (PMA) were grown on gadolinium gallium garnet (GGG) (111) substrates by off-axis sputtering. High-resolution synchrotron radiation X-ray diffraction studies and spherical aberration-corrected scanning transmission electron microscope (Cs-corrected STEM) images showed the excellent crystallinity of the films and their sharp interface with GGG. Damping constant of TmIG thin film was determined to be 0.0133 by frequency-dependent ferromagnetic resonance (FMR) measurements. The saturation magnetization (Ms) and the coercive field (Hc) were obtained systematically as a function of the longitudinal distance (L) between the sputtering target and the substrate. A 170% enhancement of PMA field (H⊥) was achieved by tuning the film composition to increase the tensile strain. Moreover, current-induced magnetization switching on a Pt/TmIG structure was demonstrated with an ultra-low critical current density (jc) of 2.5 × 106 A/cm2, an order of magnitude smaller than the previously reported value. We were able to tune Ms, Hc and H⊥ to obtain an ultra-low jc of switching the magnetization, showing the great potential of sputtered TmIG films for spintronics.

Expansion of Granulocytic, Myeloid-Derived Suppressor Cells in Response to Ethanol-Induced Acute Liver Damage

The dual role of ethanol in regulating both pro-inflammatory and anti-inflammatory response has recently been reported. Myeloid-derived suppressor cells (MDSCs) are one of the major components in the immune suppressive network in both innate and adaptive immune responses. In this study, we aim to define the role of a population expressing CD11b⁺Ly6G^highLy6C^int with immunosuppressive function in response to ethanol-induced acute liver damage. We find this increased granulocytic-MDSCs (G-MDSCs) population in the blood, spleen, and liver of mice treated with ethanol. Depletion of these cells increases serum alanine aminotransferase and aspartate aminotransferase levels, while G-MDSCs population adoptive transfer can ameliorate liver damage induced by ethanol, indicating the protective role in the early stage of alcoholic liver disease. The significant changes of T-cell profiles after G-MDSCs populations adoptive transfer and anti-Gr1 injection signify that both cytotoxic T and T helper cells might be the targeted cells of G-MDSCs. In the in vitro study, we find that myeloid precursors preferentially generate G-MDSCs and improve their suppressive capacity via chemokine interaction and YAP signaling when exposed to ethanol. Furthermore, IL-6 serves as an important indirect factor in mediating the expansion of G-MDSCs populations after acute ethanol exposure. Collectively, we show that expansion of G-MDSCs in response to ethanol consumption plays a protective role in acute alcoholic liver damage. Our study provides novel evidence of the immune response to acute ethanol consumption.

High-throughput optimization of the chemically defined synthetic medium for the production of erythromycin A

Erythromycin A is an important antibiotic. A chemically defined synthetic medium for erythromycin production was systematically optimized in this study. A high-throughput method was employed to reduce the number of components and optimize the concentration of each component. After two round single composition deletion experiment, only 19 components were remained in the medium, and then the concentration of each component was optimized through PB experiment. The optimal medium from the PB experiment was further optimized according to the nitrogen and phosphate metabolic consumption in 5 L bioreactor. It was observed that among the 8 amino acids concluded in the media, 4 amino acids were first consumed, when they are almost depleted, the other 4 amino acids were initiated their consumption afterwards in 5 L bioreactor. The decrease of phosphate concentration would increase q_glc and q_ery. However, when phosphate concentration was too low, the production of erythromycin was hindered. The positive correlation between intracellular metabolite pools and Y_ery/glc indicated that low phosphate concentration in the medium can promote cell metabolism especially secondary metabolism during the stationary phase; however, if it was too low (5 mmol/L), the cell metabolism and secondary metabolism would both slow down. The erythromycin titer in the optimized medium (medium V) reached 1380 mg/L, which was 17 times higher than the previously used synthetic medium in our lab. The optimized medium can facilitate the metabolomics study or metabolic flux analysis of the erythromycin fermentation process, which laid a solid foundation for further study of erythromycin fermentation process.

Repression of WT1-Mediated LEF1 Transcription by Mangiferin Governs β-Catenin-Independent Wnt Signalling Inactivation in Hepatocellular Carcinoma

BACKGROUND/AIMS

The development of hepatocellular carcinoma (HCC) is a complex process which involves deregulation of multiple signalling pathways. The hyper-activation of Wnt signalling promotes sustained expansion, invasion, and neovascularization of HCC. Mangiferin, a natural small molecule present in Mangifera indica L. has been shown to inactivate β-catenin, which is an indispensable regulator in Wnt pathway. Our study aimed to determine whether mangiferin has any inhibitory effect on HCC and examine how it modulates Wnt signalling.

METHODS

The tumour inhibitory effect of mangiferin was examined by in vitro cellular models and an in vivo orthotopic HCC implantation model. The genes responsible for mangiferin-mediated anti-HCC were delineated by polymerase chain reaction (PCR) microarray. The expression of target genes was further determined by quantitative PCR and immuno-blotting assays. The binding capacity of Wilms' tumour 1 (WT1) to the lymphoid enhancer-binding factor 1 (LEF1) promoter was confirmed by chromatin immunoprecipitation-qPCR.

RESULTS

Oral administration of mangiferin inhibited orthotopic tumour growth. Cellular investigations confirmed the dose-dependent inhibition of mangiferin on HCC expansion and invasion. PCR array combined with Gene Ontology analysis revealed that the Wnt pathway was the predominant target of mangiferin and LEF1 was the most reduced gene in the Wnt pathway. Overexpression of LEF1 diminished repression of Wnt signalling and reduced proliferation activity in mangiferin-treated HCC cells. The mangiferin-mediated down-regulation of LEF1 was independent of β-catenin but associated with WT1 protein. WT1 knock-in in HCC cells further enhanced LEF1 expression. Chromatin immunoprecipitation assays revealed that the mangiferin induced repression of LEF1 was associated with decreased occupancy of WT1 on the LEF1 promoter.

CONCLUSION

Our study identifies a novel mechanism of hepatocellular carcinoma inhibition through β-catenin-independent Wnt signalling, which is regulated by WT1-associated LEF1 repression. The study also highlights mangiferin as a promising Wnt inhibitor for HCC treatment.

Clinicopathological features and outcome of type 3 gastric neuroendocrine tumours

BACKGROUND

With the widespread use of endoscopy, small and low-grade type 3 gastric neuroendocrine tumours (NETs) are increasingly being detected. The clinicopathological features, biological behaviour and appropriate treatment strategy for these NETs remain unclear.

METHODS

Patients with biopsy-proven gastric NET and a normal fasting serum gastrin level were identified from a prospectively maintained database. Clinicopathological features and long-term outcome of local resection for type 3 NETs were reviewed retrospectively and compared according to tumour grade.

RESULTS

Some 32 patients with type 3 gastric NETs were included (25 patients with NET grade G1, 5 with G2 and 2 with G3). Pathological tumour size was 2·0 cm or less in 30 patients. All tumours were well differentiated, even G3 lesions, and all tumours but one were confined to the submucosal layer. G1 NETs were significantly smaller and had a significantly lower lymphovascular invasion rate than G2 and G3 NETs. Twenty-two patients with a G1 NET without lymphovascular invasion were treated with wedge or endoscopic resection. After a median follow-up of 59 (range 6-102) months, no patient with a G1 NET of 1·5 cm or smaller developed recurrence and one patient with a G1 NET larger than 1·5 cm had recurrence in a perigastric lymph node. Among seven patients with a G2 or G3 NET, two had lymph node metastasis and one had liver metastases.

CONCLUSION

Low-grade type 3 gastric NET has non-aggressive features and a favourable prognosis. Wedge or endoscopic resection may be a valid option for patients with type 3 gastric G1 NET no larger than 1·5 cm without lymphovascular invasion.

Gynostemma pentaphyllum Attenuates the Progression of Nonalcoholic Fatty Liver Disease in Mice: A Biomedical Investigation Integrated with In Silico Assay

Nonalcoholic fatty liver disease (NAFLD) is the most common type of liver disease in developed countries. Oxidative stress plays a critical role in the progression of NAFLD. Modern pharmacological study and clinical trials have demonstrated the remarkable antioxidant activity of Gynostemma pentaphyllum (GP) in chronic liver disease. One aim of this study was to explore the potential protective effects and mechanisms of action of GP extract on NAFLD. The in vivo results showed that GP extract could alleviate fatty degeneration and haptic fibrosis in NAFLD mice. For exploring the hepatoprotective mechanisms of GP, we used network pharmacology to predict the potential active components of GP and their intracellular targets in NAFLD. Based on the network pharmacology results, we further utilized biomedical assays to validate this in silico prediction. The results showed that Gypenoside XL could upregulate the protein level of PPARα in NAFLD; the transcription level of several PPARα downstream target genes such as acyl-CoA oxidase (ACO) and carnitine palmitoyltransferase-1 (CPT-1) also increased after Gypenoside XL treatment. The overexpression of ACO and CPT-1 may involve the hepatoprotective effects of GP and Gypenoside XL on NAFLD by regulating mitochondrial fatty acid β-oxidation.

Clinical significance of BECLIN1 and ATG5 expression in acute myeloid leukemia patients

INTRODUCTION

In acute myeloid leukemia (AML), it has been found that harnessing the autophagy process has led to leukemia cell death and had synergistic effects with chemotherapy. BECLIN1 and ATG5 are vital upstream regulators in the macroautophagy signaling pathway. Therefore, we explored the expression levels of BECLIN1 and ATG5 in AML patients and investigated their prognostic value, that of other clinical features.

METHODS

Real-time quantitative PCR was used to investigate the mRNA levels of BECLIN1 and ATG5 in 101 newly diagnosed leukemia patients.

RESULTS

AML samples with CEBPα or c-KIT mutations showed lower BECLIN1 expression levels compared with those without mutations (P=0.044 and P=0.036) and those with the c-KIT mutation showed lower ATG5 expression (P=0.040). Overexpression of BECLIN1 and ATG5 was related to a shorter overall survival (OS; P=0.02 and P=0.035) but not to disease-freesurvival (DFS). In multivariate analysis, the clinical characteristics exhibited no statistically significant differences in OS, except for the FLT3-ITD mutation (P=0.001) and age of the patients (P=0.032).

CONCLUSION

Our results indicate that high levels of BECLIN1 and ATG5 are associated with poor disease outcome. However, they are not independent risk factors for AML and further studies are needed to verify the underlying mechanism.

Wogonin Suppresses the Activity of Matrix Metalloproteinase-9 and Inhibits Migration and Invasion in Human Hepatocellular Carcinoma

As one of the major active ingredients in Radix Scutellariae, wogonin has been shown to be associated with various pharmacological activities on cancer cell growth, apoptosis, and cell invasion and migration. Here, we demonstrated that wogonin may harbor potential anti-metastatic activities in hepatocarcinoma (HCC). The anti-metastasis potential of wogonin and its underlying mechanisms were evaluated by ligand–protein docking approach, surface plasmon resonance assay, and in vitro gelatin zymography studies. Our results showed that wogonin (100 μM, 50 μM) suppressed MHCC97L and PLC/PRF/5 cells migration and invasion in vitro. The docking approach and surface plasmon resonance assay indicated that the potential binding affinity between wogonin and matrix metalloproteinase-9 (MMP-9) may lead to inhibition of MMP-9 activity and further leads to suppression of tumor metastasis. This conclusion was further verified by Western blot results and gelatin zymography analysis. Wogonin might be a potent treatment option for disrupting the tumor metastasis that favors HCC development. The potential active targets from computational screening integrated with biomedical study may help us to explore the molecular mechanism of herbal medicines.

The Potential and Action Mechanism of Polyphenols in the Treatment of Liver Diseases

Liver disease, involving a wide range of liver pathologies from fatty liver, hepatitis, and fibrosis to cirrhosis and hepatocellular carcinoma, is a serious health problem worldwide. In recent years, many natural foods and herbs with abundant phytochemicals have been proposed as health supplementation for patients with hepatic disorders. As an important category of phytochemicals, natural polyphenols have attracted increasing attention as potential agents for the prevention and treatment of liver diseases. The striking capacities in remitting oxidative stress, lipid metabolism, insulin resistance, and inflammation put polyphenols in the spotlight for the therapies of liver diseases. It has been reported that many polyphenols from a wide range of foods and herbs exert therapeutic effects on liver injuries via complicated mechanisms. Therefore, it is necessary to have a systematical review to sort out current researches to help better understand the potentials of polyphenols in liver diseases. In this review, we aim to summarize and update the existing evidence of natural polyphenols in the treatment of various liver diseases by in vitro, in vivo, and clinical studies, while special attention is paid to the action mechanisms.

Epstein-Barr Virus-associated Hemophagocytic Lymphohistiocytosis in Adults: A Retrospective Analysis of 23 Patients in China

BACKGROUND

Epstein-Barr virus (EBV)-associated hemophagocytic lymphohistiocytosis (HLH) is a rare, life-threatening disease with poor prognosis despite intensive therapy.

OBJECTIVES

To discuss the ideal therapy of EBV-associated HLH for adults.

METHODS

We retrospectively studied 23 adult patients with EBV-associated HLH at our institution between January 2000 and June 2015. The clinical characteristics, treatment, and prognosis of adult EBV-associated HLH were analyzed. The median age was 38 years (range 18-72).

RESULTS

All patients were found to have high fever, thrombocytopenia, abnormal liver function, elevated ferritin, and lactate dehydrogenase. Leukopenia, anemia, coagulopathy, hypofibrinogenemia, and splenomegaly were found in more than 80% of patients. Ten patients were treated with HLH-2004 protocol. Eventually, 95.7% of patients died of EBV-associated HLH. Non-HLH-2004 treatment and bone marrow suppression may predict early relapse independently, and the poor performance status and high lactate dehydrogenase level can be poor prognostic factors. It was also validated in comprehensive analysis of published articles.

CONCLUSIONS

Adult EBV-associated HLH occurs most often in people of Asian descent who are older than 35 years. These patients had a disappointing outcome despite intensive treatment, especially with high lactate dehydrogenase levels, poor performance status, and bone marrow suppression. HLH-2004 protocol has shown a glimmer of hope in the adult populations.

Strongly exchange-coupled and surface-state-modulated magnetization dynamics in Bi2Se3/yttrium iron garnet heterostructures

Harnessing the spin–momentum locking of topological surface states in conjunction with magnetic materials is the first step to realize novel topological insulator-based devices. Here, we report strong interfacial coupling in Bi₂Se₃/yttrium iron garnet (YIG) bilayers manifested as large interfacial in-plane magnetic anisotropy (IMA) and enhancement of damping probed by ferromagnetic resonance. The interfacial IMA and damping enhancement reaches a maximum when the Bi₂Se₃ film approaches its two-dimensional limit, indicating that topological surface states play an important role in the magnetization dynamics of YIG. Temperature-dependent ferromagnetic resonance of Bi₂Se₃/YIG reveals signatures of the magnetic proximity effect of T_C as high as 180 K, an emerging low-temperature perpendicular magnetic anisotropy competing the high-temperature IMA, and an increasing exchange effective field of YIG steadily increasing toward low temperature. Our study sheds light on the effects of topological insulators on magnetization dynamics, essential for the development of topological insulator-based spintronic devices.

Understanding the effects of topological insulators on magnetization dynamics of adjacent magnetic materials is essential for novel spintronic devices. Here, Fanchiang et al. report thickness dependence of interfacial in-plane magnetic anisotropy and damping enhancement in Bi₂Se₃/yttrium iron garnet (YIG) bilayers, indicating an important role of topological surface states in the magnetization dynamics of YIG.

The synergy of Vitamin C with decitabine activates TET2 in leukemic cells and significantly improves overall survival in elderly patients with acute myeloid leukemia

BACKGROUND

Decitabine is widely used in the treatment of acute myeloid leukemia (AML) in elderly patients. Low-dose Vitamin C has also been indicated to induce DNA demethylation at the cellular level. However, little is known whether low-dose Vitamin C has a synergistic effect with decitabine in clinic.

METHODS

The effect of combined low-dose Vitamin C and decitabine on cell proliferation, the cell cycle, apoptosis and the expression level and activity of TET2 was investigated in HL60 and NB4 human leukemic cells. Additionally, we analyzed the clinical outcomes of 73 elderly AML patients who received A-DCAG (intravenous Vitamin C [IVC] plus DCAG [n = 39]) or DCAG (n = 34) treatment.

RESULTS

We found that low-dose Vitamin C and decitabine has a synergistic efficacy on proliferation, apoptosis, TET2 expression and activity, compared to drug-alone treatment in HL60 and NB4 cell lines in vitro. In clinic, feasibility and safety evaluations revealed that patients who received A-DCAG regimen have a higher complete remission (CR) rate than those who received the DCAG regimen (79.92% vs. 44.11%; P = 0.004) after one cycle of chemotherapy. The median overall survival (OS) was better in the A-DCAG group compared with the DCAG group (15.3 months vs. 9.3 months, P = 0.039). Patients with adverse cytogenetics did benefit from CR. There was no clinically significant additional toxicity observed with the addition of IVC.

CONCLUSION

On the basis of these results, the addition of IVC at low doses to DCAG appeared to improve CR and prolong OS, compared with DCAG, in elderly patients with AML.