The no-observed-adverse-effect level of phthalates promotes proliferation and cell cycle progression in normal human breast cells.

OBJECTIVE: The data on the association between phthalates and breast cancer risk remains inconsistent. This study aimed to explore the possible mechanism of low-dose exposures of phthalates, including Butyl benzyl phthalate (BBP), di(n-butyl) phthalate (DBP), and di(20ethylhexyl) phthalate (DEHP), on breast tumorigenesis. METHODS AND METHODS: MCF-10A normal breast cells were treated with phthalates (10 and 100 nM) and 17ß-estradiol (E2, 10 nM), which were co-cultured with fibroblasts from normal mammary tissue. Cell viability, cycle, and apoptosis were detected by MTT assay, flow cytometry, and TUNEL assay respectively. The expression levels of related proteins were determined by Western blot. RESULTS: Like E2, both 10 nM and 100 nM phthalates exerted significantly higher cell viability, lower apoptosis, and increased cell numbers in the S and G2/M phases with up-regulation of cyclin D/CDK4, cyclin E/CDK2, cyclin A/CDK2, cyclin A/CDK1, and cyclin B/CDK1, compared with the control group. Significant increase in PDK1, P13K, p-AKT, p-mTOR, and BCL-2 expression and a decrease in Bax protein, cytochrome C, caspase 8, and caspase 3 levels were noted in cells treated with 10 nM and 100 nM phthalates and E2, compared with the control group and MCF-10A cells co-cultured with fibroblasts. The effects of the three phthalates were noted to be dose-dependent. CONCLUSIONS: The results indicate that phthalates at a level below its no-observed-adverse-effect concentration, as defined by the current standards, still induce cell cycle progression and proliferation as well as inhibit apoptosis of normal breast cells. Thus, the possibility of breast tumorigenesis through chronic phthalate exposure should be considered.

Regulation of the cell cycle and P13K/AKT/mTOR signaling pathway by phthalates in normal human breast cells.

OBJECTIVE: To investigate the impact of phthalates, including Butyl benzyl phthalate (BBP), di(n-butyl) phthalate (DBP), and di(2-ethylhexyl) phthalate (DEHP), in breast carcinogenesis. MATERIALS AND METHODS: MCF-10A normal breast cells were treated with phthalates (100 nM) and 17ß-estradiol (E2, 10 nM), which were co-cultured with fibroblasts from normal mammary tissue adjacent to estrogen receptor positive primary breast cancers. Cell viability was determined using a 3-(4,5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. Cell cycles were analyzed using flow cytometry. The proteins involving cell cycles and P13K/AKT/mTOR signaling pathway were then evaluated by Western blot analysis. RESULTS: MCF-10A co-cultured cells treated with E2, BBP, DBP, and DEHP exhibited a significant increase in cell viability using MTT assay. The expressions of P13K, p-AKT, and p-mTOR, as well as PDK1 expression, were significantly higher in MCF-10A cells treated with E2 and phthalates. E2, BBP, DBP, and DEHP significantly increased cell percentages in the S and G2/M phases. The significantly higher expression of cyclin D/CDK4, cyclin E/CDK2, cyclin A/CDK2, cyclin A/CDK1, and cyclin B/CDK1 in MCF-10A co-cultured cells were induced by E2 and these three phthalates. CONCLUSION: These results provide consistent data regarding the potential role of phthalates exposure in the stimulating proliferation of normal breast cells, enhancing cell viability, and driving P13K/AKT/mTOR signaling pathway and cell cycle progression. These findings strongly support the hypothesis that phthalates may play a crucial role in breast tumorigenesis.

CRISPR-Cas9-mediated gene editing of the BCL11A enhancer for pediatric ß0/ß0 transfusion-dependent ß-thalassemia.

Gene editing to disrupt the GATA1-binding site at the +58 BCL11A erythroid enhancer could induce γ-globin expression, which is a promising therapeutic strategy to alleviate ß-hemoglobinopathy caused by HBB gene mutation. In the present study, we report the preliminary results of an ongoing phase 1/2 trial (NCT04211480) evaluating safety and efficacy of gene editing therapy in children with blood transfusion-dependent ß-thalassemia (TDT). We transplanted BCL11A enhancer-edited, autologous, hematopoietic stem and progenitor cells into two children, one carrying the ß0/ß0 genotype, classified as the most severe type of TDT. Primary endpoints included engraftment, overall survival and incidence of adverse events (AEs). Both patients were clinically well with multilineage engraftment, and all AEs to date were considered unrelated to gene editing and resolved after treatment. Secondary endpoints included achieving transfusion independence, editing rate in bone marrow cells and change in hemoglobin (Hb) concentration. Both patients achieved transfusion independence for >18 months after treatment, and their Hb increased from 8.2 and 10.8 g dl-1 at screening to 15.0 and 14.0 g dl-1 at the last visit, respectively, with 85.46% and 89.48% editing persistence in bone marrow cells. Exploratory analysis of single-cell transcriptome and indel patterns in edited peripheral blood mononuclear cells showed no notable side effects of the therapy.

HRS phosphorylation drives immunosuppressive exosome secretion and restricts CD8+ T-cell infiltration into tumors.

The lack of tumor infiltration by CD8+ T cells is associated with poor patient response to anti-PD-1 therapy. Understanding how tumor infiltration is regulated is key to improving treatment efficacy. Here, we report that phosphorylation of HRS, a pivotal component of the ESCRT complex involved in exosome biogenesis, restricts tumor infiltration of cytolytic CD8+ T cells. Following ERK-mediated phosphorylation, HRS interacts with and mediates the selective loading of PD-L1 to exosomes, which inhibits the migration of CD8+ T cells into tumors. In tissue samples from patients with melanoma, CD8+ T cells are excluded from the regions where tumor cells contain high levels of phosphorylated HRS. In murine tumor models, overexpression of phosphorylated HRS increases resistance to anti-PD-1 treatment, whereas inhibition of HRS phosphorylation enhances treatment efficacy. Our study reveals a mechanism by which phosphorylation of HRS in tumor cells regulates anti-tumor immunity by inducing PD-L1+ immunosuppressive exosomes, and suggests HRS phosphorylation blockade as a potential strategy to improve the efficacy of cancer immunotherapy.

CST6 suppresses osteolytic bone disease in multiple myeloma by blocking osteoclast differentiation.

Osteolytic bone disease is a hallmark of multiple myeloma (MM). A significant fraction (~20%) of MM patients do not develop osteolytic lesions (OLs). The molecular basis for the absence of bone disease in MM is not understood. We combined PET-CT and gene expression profiling (GEP) of purified BM CD138+ MM cells from 512 newly diagnosed MM patients to reveal that elevated expression of cystatin M/E (CST6) was significantly associated with the absence of OL in MM. An enzyme-linked immunosorbent assay revealed a strong correlation between CST6 levels in BM serum/plasma and CST6 mRNA expression. Both recombinant CST6 protein and BM serum from patients with high CST6 significantly inhibited the activity of the osteoclast-specific protease cathepsin K and blocked osteoclast differentiation and function. Recombinant CST6 inhibited bone destruction in ex vivo and in vivo myeloma models. Single-cell RNA-Seq showed that CST6 attenuates polarization of monocytes to osteoclast precursors. Furthermore, CST6 protein blocks osteoclast differentiation by suppressing cathepsin-mediated cleavage of NF-κB/p100 and TRAF3 following RANKL stimulation. Secretion by MM cells of CST6, an inhibitor of osteoclast differentiation and function, suppresses osteolytic bone disease in MM and probably other diseases associated with osteoclast-mediated bone loss.

Inflammation Status and Body Composition Predict Two-Year Mortality of Patients with Locally Advanced Head and Neck Squamous Cell Carcinoma under Provision of Recommended Energy Intake during Concurrent Chemoradiotherapy.

Only few prospective cohort trials have evaluated the risk factors for the 2-year mortality rate between two patient subgroups with locally advanced head and neck squamous cell carcinoma (LAHNSCC): oral cavity cancer with adjuvant concurrent chemoradiotherapy (CCRT) (OCC) and non-oral cavity cancer with primary CCRT (NOCC), under the recommended calorie intake and investigated the interplay among calorie supply, nutrition-inflammation biomarkers (NIBs), and total body composition change (TBC), as assessed using dual-energy X-ray absorptiometry (DXA). Patients with LAHNSCC who consumed at least 25 kcal/kg/day during CCRT were prospectively recruited. Clinicopathological variables, blood NIBs, CCRT-related factors, and TBC data before and after treatment were collected. Factor analysis was performed to reduce the number of anthropometric and DXA-derived measurements. Cox proportional hazards models were used for analysis. We enrolled 123 patients with LAHNSCC (69 with OCC and 54 with NOCC). The mean daily calorie intake correlated with the treatment interval changes in total body muscle and fat. Patients consuming ≥30 kcal/kg/day had lower pretreatment levels but exhibited fewer treatment interval changes in anthropometric and DXA measurements than patients consuming <30 kcal/kg/day. In the multivariate analysis of the 2-year mortality rate, the prognostic influence of the recommended calorie intake could not be confirmed, but different risk factors (performance status, pretreatment platelet-to-lymphocyte ratio, and treatment interval body muscle changes in patients with OCC; age, pretreatment neutrophil-to-lymphocyte ratio, and body fat storage in patients with NOCC) showed independent effects. Therefore, the inflammation status and body composition, but not the recommended calorie supply, contribute to the 2-year mortality rate for patients with LAHNSCC receiving CCRT.

Chidamide, a subtype-selective histone deacetylase inhibitor, enhances Bortezomib effects in multiple myeloma therapy.

Drug resistance is the major cause for disease relapse and patient death in multiple myeloma (MM). It is an urgent need to develop new therapies to overcome drug resistance in MM. Chidamide (CHI), a novel oral HDAC inhibitor targeting HDAC1, 2, 3 and 10, has shown potential therapeutic effect in MM. In this study, we determined that CHI exhibited significant anti-tumor effect on MM cells both in vitro and in vivo, which was positively correlated with the expression of HDAC1. Meanwhile, CHI enhanced Bortezomib (BTZ) effects synergistically in MM cells and a combination of CHI with BTZ induced myeloma cell apoptosis and G0/G1 arrest in vitro and in vivo. Mechanistically, the synergistic anti-tumor effect of CHI and BTZ was related with the increased production of reactive oxygen species (ROS) dependent DNA damage and the changes of cell apoptosis and cycle pathways. Our data indicate that CHI may be a suitable drug to sensitize BTZ in MM cells, which provides novel insight into the therapy for MM patients.

Concurrent Chemoradiotherapy Induces Body Composition Changes in Locally Advanced Head and Neck Squamous Cell Carcinoma: Comparison between Oral Cavity and Non-Oral Cavity Cancer.

Few prospective cohort trials have evaluated the difference in treatment-interval total body composition (TBC) changes assessed by dual-energy X-ray absorptiometry (DXA) between two patient subgroups with locally advanced head and neck squamous cell carcinoma (LAHNSCC) receiving concurrent chemoradiotherapy (CCRT): oral cavity cancer with adjuvant CCRT (OCC) and non-oral cavity with primary CCRT (NOCC). This study prospectively recruited patients with LAHNSCC. Clinicopathological variables, blood nutritional/inflammatory markers, CCRT-related factors, and TBC data assessed by DXA before and after treatment were collected. Multivariate linear regression analysis identified the factors associated with treatment-interval changes in body composition parameters, including lean body mass (LBM), total fat mass (TFM), and bone mineral content (BMC). A total of 127 patients (OCC (n = 69) and NOCC (n = 58)) were eligible. Body composition parameters were progressively lost during CCRT in both subgroups. Extremities lost more muscle mass than the trunk for LBM, whereas the trunk lost more fat mass than the extremities for TFM. BMC loss preferentially occurred in the trunk region. Different factors were independently correlated with the interval changes of each body composition parameter for both OCC and NOCC subgroups, particularly mean daily calorie intake for LBM and TFM loss, and total lymphocyte count for BMC loss. In conclusion, treatment-interval TBC changes and related contributing factors differ between the OCC and NOCC subgroups.

Comorbidity, Radiation Duration, and Pretreatment Body Muscle Mass Predict Early Treatment Failure in Taiwanese Patients with Locally Advanced Oral Cavity Squamous Cell Carcinoma after Completion of Adjuvant Concurrent Chemoradiotherapy.

Few prospective cohort trials have evaluated the potential risk factors of early treatment failure of locally advanced oral cavity squamous cell carcinoma (LAOCSCC) patients following the completion of postoperative adjuvant concurrent chemoradiotherapy (CCRT). We collected clinicopathological variables, nutrition-inflammatory markers and total body composition data assessed by dual-energy X-ray absorptiometry (DXA) before and after CCRT. A factor analysis was used to reduce the number of DXA-derived parameters. Cox proportional hazard models were applied to determine the risk factors associated with early treatment failure defined as tumor progression or death within 180 days of CCRT completion. A total of 69 patients were eligible for analysis. After CCRT, the body weight, body mass index, nutritional markers, and muscle mass decreased, whereas C-reactive protein level increased. Five factors reflecting different body composition statuses were identified. A total of 21 patients (30.4%) developed early treatment failure. Comorbidities (hazard ratio ((HR)), 2.699; 95% confidence interval ((CI)), 1.005-7.913; p = 0.044), radiation duration (HR, 1.092; 95% CI, 1.015-1.174; p = 0.018) and the pretreatment body muscle mass (HR, 0.578; 95% CI, 0.345-0.957; p = 0.037) independently contributed to early treatment failure. Comorbidities, longer radiation duration, and lower pretreatment body muscle mass are predictive factors for early treatment failure in LAOCSCC patients following postoperative adjuvant CCRT completion.

Chidamide-Induced Accumulation of Reactive Oxygen Species Increases Lenalidomide Sensitivity Against Multiple Myeloma Cells.

BACKGROUND: Lenalidomide, an immunomodulatory drug (IMiD), is an effective therapy for the treatment of multiple myeloma (MM). However, prolonged treatment may be accompanied by toxicity, second primary malignancies, and drug resistance. There is an inherent vulnerability in MM cells that high rates of immunoglobulin synthesis resulting in the high level of reactive oxygen species (ROS). This provides a therapeutic potential for MM. MATERIALS AND METHODS: The intracellular ROS levels, H2O2 production and glutathione (GSH) levels were measured using detection kit. Cell viability was evaluated using cell-counting kit-8 (CCK-8) and soft agar colony formation assay. Apoptosis was determined in whole living cells using flow cytometry. Chidamide and its anti-myeloma efficacy in combination with lenalidomide were characterized in MM cell lines in vitro and in a mouse xenograft model. Moreover, Western blotting, immunofluorescence and immunohistochemical studies were performed. RESULTS: ROS levels increased in a time- and dose-dependent manner with chidamide treatment. Moreover, the GSH levels were decreased and the mRNA level of SLC7A11 downregulated after chidamide treatment. The co-treatment with chidamide and lenalidomide increased apoptosis and proliferation inhibition, with combination index (CI) in the synergistic range (0.2-0.5) using the Chou-Talalay method. The cooperative anti-myeloma efficacy was confirmed in the murine model, and immunohistochemical studies also supported this potentiation. Chidamide enhanced the effect of lenalidomide-induced degradation of IKZF1 and IKZF3 by elevating H2O2. In addition, co-treatment with chidamide and lenalidomide increased biomarkers of caspase and DNA damage. CONCLUSION: Elevated ROS production may constitute a potential biochemical basis for anti-myeloma effects of chidamide plus lenalidomide. The results of this study confirm the synergistic effect of chidamide and lenalidomide against MM and provide a promising therapeutic strategy for MM.

Pyruvate dehydrogenase kinase 4-mediated metabolic reprogramming is involved in rituximab resistance in diffuse large B-cell lymphoma by affecting the expression of MS4A1/CD20.

Diffuse large B cell lymphoma (DLBCL) heterogeneity promotes recurrence and anti-CD20-based therapeutic resistance. Previous studies have shown that downregulation of MS4A1/CD20 expression after chemoimmunotherapy with rituximab leads to rituximab resistance. However, the mechanisms of CD20 loss remain unknown. We identified that pyruvate dehydrogenase kinase 4 (PDK4) is markedly elevated in DLBCL cells derived from both patients and cell lines with R-CHOP (rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone) resistance. We found that overexpression of PDK4 in DLBCL cells resulted in cell proliferation and resistance to rituximab in vitro and in vivo. Furthermore, loss of PDK4 expression or treatment with the PDK4 inhibitor dichloroacetate was able to significantly increase rituximab-induced cell apoptosis in DLBCL cells. Further studies suggested PDK4 mediates a metabolic shift, in that the main energy source was changed from oxidative phosphorylation to glycolysis, and the metabolic changes could play an important role in rituximab resistance. Importantly, by knocking down or overexpressing PDK4 in DLBCL cells, we showed that PDK4 has a negative regulation effect on MS4A1/CD20 expression. Collectively, this is the first study showing that targeting PDK4 has the potential to overcome rituximab resistance in DLBCL.

TRIP13 modulates protein deubiquitination and accelerates tumor development and progression of B cell malignancies.

Multiple myeloma (MM), a terminally differentiated B cell malignancy, remains difficult to cure. Understanding the molecular mechanisms underlying the progression of MM may identify therapeutic targets and lead to a fundamental shift in treatment of the disease. Deubiquitination, like ubiquitination, is a highly regulated process, implicated in almost every cellular process. Multiple deubiquitinating enzymes (DUBs) have been identified, but their regulation is poorly defined. Here, we determined that TRIP13 increases cellular deubiquitination. Overexpression of TRIP13 in mice and cultured cells resulted in excess cellular deubiquitination by enhancing the association of the DUB USP7 with its substrates. We show that TRIP13 is an oncogenic protein because it accelerates B cell tumor development in transgenic mice. TRIP13-induced resistance to proteasome inhibition can be overcome by a USP7 inhibitor in vitro and in vivo. These findings suggest that TRIP13 expression plays a critical role in B cell lymphoma and MM by regulating deubiquitination of critical oncogenic (NEK2) and tumor suppressor (PTEN, p53) proteins. High TRIP13 identifies a high-risk patient group amenable to adjuvant anti-USP7 therapy.

PRICKLE1, a Wnt/PCP signaling component, is overexpressed and associated with inferior prognosis in acute myeloid leukemia.

BACKGROUND: Prickle planar cell polarity protein 1 (PRICKLE1), a core component of the non-canonical Wnt/planar cell polarity (PCP) pathway, was recently reported to be upregulated and correlated with poor prognosis in solid cancers. However, the effect of PRICKLE1 on acute myeloid leukemia (AML) remains unknown. This study aims to characterize the prognostic significance of PRICKLE1 expression in patients with AML. METHODS: RNA-seq was performed to compare mRNA expression profiles of AML patients and healthy controls. qRT-PCR and western blotting were used to analyze the expression of PRICKLE1 in AML patients and cell lines, and two independent datasets (TCGA-LAML and TARGET-AML) online were used to validate the expression results. The correlations between the expression of PRICKLE1 and clinical features were further analyzed. RESULTS: Our data showed that PRICKLE1 expression levels were markedly high in AML patients at the time of diagnosis, decreased after complete remission and increased again at relapse. Of note, PRICKLE1 was highly expressed in drug resistant AML cells and monocytic-AML patients. High PRICKLE1 expression was found in FLT3/DNMT3A/IDH1/IDH2-mutant AML and associated with poor prognosis. Furthermore, high expression of PRICKLE1 may be correlated with migration and invasion components upregulation in AML patients. CONCLUSIONS: These results indicated that high PRICKLE1 expression may be a poor prognostic biomarker and therapeutic target of AML.

A small molecule binding HMGB1 inhibits caspase-11-mediated lethality in sepsis.

Caspase-11, a cytosolic lipopolysaccharide (LPS) receptor, mediates lethal immune responses and coagulopathy in sepsis, a leading cause of death worldwide with limited therapeutic options. We previously showed that over-activation of caspase-11 is driven by hepatocyte-released high mobility group box 1 (HMGB1), which delivers extracellular LPS into the cytosol of host cells during sepsis. Using a phenotypic screening strategy with recombinant HMGB1 and peritoneal macrophages, we discovered that FeTPPS, a small molecule selectively inhibits HMGB1-mediated caspase-11 activation. The physical interaction between FeTPPS and HMGB1 disrupts the HMGB1-LPS binding and decreases the capacity of HMGB1 to induce lysosomal rupture, leading to the diminished cytosolic delivery of LPS. Treatment of FeTPPS significantly attenuates HMGB1- and caspase-11-mediated immune responses, organ damage, and lethality in endotoxemia and bacterial sepsis. These findings shed light on the development of HMGB1-targeting therapeutics for lethal immune disorders and might open a new avenue to treat sepsis.

Role of the Appendicular Skeletal Muscle Index for Predicting the Recurrence-Free Survival of Head and Neck Cancer.

BACKGROUND: This study investigates whether the appendicular skeletal muscle index (ASMI) was an independent prognostic predictor for patients with locally advanced head and neck cancer (LAHNC) receiving concurrent chemoradiotherapy (CCRT) and whether there were any differences in lean mass loss in different body regions during CCRT. METHODS: In this prospective study, we analyzed the clinicopathological variables and the total body composition data before and after treatment. The factors associated with the 2-year recurrence-free survival rate (RFSR) were analyzed via logistic regression analysis. RESULTS: A total of 98 patients were eligible for analysis. The body weight, body mass index, and all parameters of body composition significantly decreased after CCRT. The pretreatment ASMI was the only independent prognostic factor for predicting the 2-year RFSR (hazard ratio, 0.235; 95% confidence interval, 0.062-0.885; p = 0.030). There was at least 5% reduction in total lean and fat mass (p < 0.001); however, the highest lean mass loss was observed in the arms (9.5%), followed by the legs (7.2%), hips (7.1%), waist (4.7%), and trunk (3.6%). CONCLUSIONS: The pretreatment ASMI was the only independent prognostic predictor for the 2-year RFSR of LAHNC patients undergoing CCRT. Asynchronous loss of lean mass may be observed in different body parts after CCRT.

Genetic Analysis of Multiple Myeloma Identifies Cytogenetic Alterations Implicated in Disease Complexity and Progression.

Multiple myeloma (MM) is a genetically heterogeneous disease characterized by genomic chaos making it difficult to distinguish driver from passenger mutations. In this study, we integrated data from whole genome gene expression profiling (GEP) microarrays and CytoScan HD high-resolution genomic arrays to integrate GEP with copy number variations (CNV) to more precisely define molecular alterations in MM important for disease initiation, progression and poor clinical outcome. We utilized gene expression arrays from 351 MM samples and CytoScan HD arrays from 97 MM samples to identify eight CNV events that represent possible MM drivers. By integrating GEP and CNV data we divided the MM into eight unique subgroups and demonstrated that patients within one of the eight distinct subgroups exhibited common and unique protein network signatures that can be utilized to identify new therapeutic interventions based on pathway dysregulation. Data also point to the central role of 1q gains and the upregulated expression of ANP32E, DTL, IFI16, UBE2Q1, and UBE2T as potential drivers of MM aggressiveness. The data presented here utilized a novel approach to identify potential driver CNV events in MM, the creation of an improved definition of the molecular basis of MM and the identification of potential new points of therapeutic intervention.

Determining Malnutrition Assessment Criteria to Predict One-Year Mortality for Locally Advanced Head and Neck Cancer Patients Undergoing Concurrent Chemoradiotherapy.

Study on the impact of pretreatment malnutrition on treatment outcomes in locally advanced head and neck cancer (LAHNC) patients is still lacking. We prospectively collected various malnutrition assessment methods including nutrition indexes, inflammatory biomarkers, and lean body mass index (LBMI) data before treatments. The one year mortality rate was assessed, and the factors associated with this outcome were investigated. Furthermore, the association between malnutrition assessment methods was examined. A total of 113 patients were enrolled. By prognostic stratification based on the prognostic nutritional index (PNI) and platelet-to-lymphocyte ratio (PLR) combination, the low PNI/high PLR group had highest and the high PNI/low PLR group had the lowest mortality rate. Furthermore, the PNI was positively correlated with the LBMI, and the PLR was inversely correlated with the LBMI. PNI and PLR were found to be independent prognostic factors of one year mortality and also associated with the loss of muscle.

Oncogenic Roles Of A Histone Methyltransferase SETDB2 In AML1-ETO Positive AML.

INTRODUCTION: AML1-ETO produced by t(8;21) abnomality has multiple effects on the leukemogenesis of acute myeloid leukemia (AML). SET domain, bifurcated 2 (SETDB2) can mediate gene silencing by trimethylation of the ninth lysine residue of histone H3 protein (H3K9) of the promoter and has been confirmed as an oncogene in many cancers. The role of SETDB2 in AML1-ETO positive AML is not clear. METHODS: Quantitative reverse transcription PCR was performed to measure SETDB2 expression in bone marrow from AML patients and healthy people. Kaplan-Meier analysis was performed to investigate the effect of SETDB2 on prognosis of AML patients. Dual luciferase reporter gene assay, chromatin immunoprecipitation were performed to investigate the regulatory mechanism of AML1-ETO on SETDB2. CCK-8 and colony formation assay were performed to measure the effect of SETDB2 on leukemic cells. RESULTS: SETDB2 is highly expressed in AML1-ETO positive AML. The overall survival, event-free and relapse-free survival rate of patients with high SETDB2 expression was lower than those of patients with low SETDB2 expression. SETDB2 is epigenetically upregulated by AML1-ETO fusion protein. Downregulation of SETDB2 expression significantly inhibits the proliferation and clonality of leukemic cells and promotes the sensitivity of leukemic cells to an epigenetic inhibitor JQ1. CONCLUSION: AML1-ETO/SETDB2 is a novel epigenetic pathway of leukemogenesis and SETDB2 is a potential therapeutic target of t(8;21) AML.

Self-assembling RATEA16 peptide nanofiber designed for rapid hemostasis.

Uncontrolled bleeding remains a contributor of mortality in various accidents, and ideal hemostatic materials with rapid and efficient hemostasis, ease of use, biocompatibility and non-toxic characteristics are urgently needed. In this study, we synthesized a novel polypeptide material, RATEA16 (CH3CO-RATARAEARATARAEA-CONH2), by the solid phase method, and investigated the secondary structure, self-assembly performance, gelation ability, biocompatibility and hemostatic efficiency in vitro and in vivo. The results showed that the RATEA16 peptide solution had an appropriate pH after replacing the strongly acidic aspartic acid with weakly acidic Glu and basic Thr in the RADA16-I backbone. The secondary structure of RATEA16 played an important role in the formation of nanofibers induced by self-assembling behavior. RATEA16 possessed good biocompatibility and rapid gelation ability. Animal liver model experiments showed that RATEA16 had a higher blood coagulation rate than CMS and Arista® and achieved complete hemostasis in about 40 seconds. Therefore, the study indicated that the self-assembled peptide RATEA16 had excellent biocompatibility and efficient hemostasis, suggesting that RATEA16 can serve as a reliable and promising hemostatic agent for rapid hemostasis.