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The assessment of biodegradable materials, such as bioactive glass, under the existing ISO 10993 standard test methods poses a significant challenge due to potential cell viability impairment caused by the accumulation of degraded products in a static environment. Therefore, innovative methodologies are urgently needed to tailor the unique biodegradation characteristics of these materials, providing more precise and scientific insights into biosafety and efficacy verification. Motivation by its bidirectional regulation of angiogenesis and immunity, zinc (Zn) was incorporated into sol-gel-derived borosilicate bioactive glasses (SBSGs) to fabricate Zn-incorporated borosilicate bioactive glasses (SBSG-Zn) to complement the tissue repair capabilities of bioactive glasses. Both SBSG and SBSG-Zn glasses consist of nanosized particles, slit mesoporous pores, high specific surface areas, and bioreactivity. In vitro comparative analysis, conducted according to ISO 10993 standards, demonstrates that only at suitable dilution ratesâsuch as the 8-fold dilution employed in this studyâdo extracts of SBSG and SBSG-Zn glasses exhibit low cytotoxicity when cultured with human umbilical vein endothelial cells (HUVECs). Notably, SBSG-Zn glasses show optimal promotion of angiogenic gene expression in HUVECs. Furthermore, within an appropriate concentration range of released ions, SBSG-Zn glass extracts not only promote cell survival but also modulate the expression of anti-inflammatory genes while simultaneously inhibiting pro-inflammatory genes concurrently. After being implanted in rat subcutaneous defect models, both SBSG and SBSG-Zn glasses demonstrated the local immunoregulation and angiogenic effects. SBSG-Zn stands out by demonstrating superior modulation of M1/M2 polarization in macrophages as validated by altered secretion of key factors in macrophages and expression of relevant growth factors in HUVECs. These findings underscore the potential for convenient manipulation of localized angiogenic and immunoregulation through the incorporation of zinc into bioactive glass, emphasizing the importance of ensuring the appropriate ion doses are applied for achieving optimal therapeutic efficiency.
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Autophagy, a highly regulated lysosome-dependent catabolic pathway, has garnered increasing attention because of its role in leukemia resistance. Among the S100 family of small calcium-binding proteins, S100P is differentially expressed in various tumor cell lines, thereby influencing tumor occurrence, invasion, metastasis, and drug resistance. However, the relationship between S100P and autophagy in determining chemosensitivity in leukemia cells remains unexplored. Our investigation revealed a negative correlation between S100P expression and the clinical status in childhood leukemia, with its presence observed in HL-60 and Jurkat cell lines. Suppression of S100P expression resulted in increased cell proliferation and decreased chemosensitivity in leukemia cells, whereas enhancement of S100P expression inhibited cell proliferation and increased chemosensitivity. Additionally, S100P knockdown drastically promoted autophagy, which was subsequently suppressed by S100P upregulation. Moreover, the p53/AMP-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) pathway was found to be functionally associated with S100P-mediated autophagy. Knockdown of S100P expression led to a decrease in p53 and p-mTOR levels and an increase in p-AMPK expression, ultimately promoting autophagy. This effect was reversed by administration of Tenovin-6 (a p53 activator) and Compound C (an AMPK inhibitor). The findings of our in vivo experiments provide additional evidence supporting the aforementioned data. Specifically, S100P inhibition significantly enhanced the growth of HL-60 tumor xenografts and increased the expression of microtubule-associated protein 1 light chain 3 and p-AMPK in nude mice. Consequently, it can be concluded that S100P plays a regulatory role in the chemosensitivity of leukemia cells by modulating the p53/AMPK/mTOR pathway, which controls autophagy in leukemia cells.
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Metal-organic frameworks (MOFs) have a high specific surface area, adjustable pores and can be used to obtain functional porous materials with diverse and well-ordered structures through coordination and self-assembly, which has intrigued wide interest in a broad range of disciplines. In the arena of biomedical engineering, the functionalized modification of MOFs has produced drug carriers with excellent dispersion and functionalities such as target delivery and response release, with promising applications in bio-detection, disease therapy, tissue healing, and other areas. This review summarizes the present state of research on the functionalization of MOFs by physical binding or chemical cross-linking of small molecules, polymers, biomacromolecules, and hydrogels and evaluates the role and approach of MOFs functionalization in boosting the reactivity of materials. On this basis, research on the application of functionalized MOFs composites in biomedical engineering fields such as drug delivery, tissue repair, disease treatment, bio-detection and imaging is surveyed, and the development trend and application prospects of functionalized MOFs as an important new class of biomedical materials in the biomedical field are anticipated, which may provide some inspiration and reference for further development of MOF for bio-medical applications.
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Amplification-free digital immunoassays (DIAs) typically utilize optical nanoparticles to enhance single immunocomplex molecule detection. The efficiency and uniformity of transferring the nanoparticles from a bulk solution to a solid surface determine the limit of detection (LOD) and the accuracy of DIAs. Previous methods suffer from issues like low efficiency, nonuniform distribution, and particle aggregation. Here, we present a novel technique named synergistic sedimentation of Brownian motion suppression and dehydration transfer (SynSed) for nanoparticles using water-soluble polymers. The efficiency of transferring quantum dots (QDs) was increased from 10.7 to 91.4%, and the variation in QD distribution was restricted to 8.8%. By incorporating SynSed into DIAs, we achieved a remarkable reduction in the LOD (down to 3.9 aM) for carcinoembryonic antigen and expanded the dynamic range to cover 3 orders of magnitude in concentration, ranging from 0.01 to 10 fM. DIAs enhanced with SynSed possess ultrahigh sensitivity, advanced accuracy, and specificity, offering a great premise in early disease diagnostics, risk stratification, and treatment response monitoring.
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Chronic hypoxia and ischemia make diabetic wounds non-healing. Cellular functions of diabetic chronic wounds are inhibited under a pathological environment. Therefore, this work develops a composite hydrogel system to promote diabetic wound healing. The composite hydrogel system consists of ε-poly-lysine (EPL), calcium peroxide (CP), and borosilicate glass (BG). The hydrogel supplies continuous dissolved oxygen molecules to the wound that can penetrate the skin tissue to restore normal cellular function and promote vascular regeneration. Biofunctional ions released from BGs can recruit more macrophages through neovascularization and modulate macrophage phenotypic transformation. Combining oxygen-mediated vascular regeneration and ion-mediated inflammatory regulation significantly accelerated diabetic wound healing. These findings indicate that this composite hydrogel system holds promise as a novel tissue engineering material.
Subject(s)
Diabetes Mellitus , Wound Healing , Humans , Hydrogels/pharmacology , Hypoxia , IonsABSTRACT
Pyroptosis, a newly discovered mode of programmed cell death (PCD), is important in the regulation of cancer development. High mobility group box 1 (HMGB1) is a non-histone nuclear protein that is closely related to tumor development and chemotherapy resistance. However, whether endogenous HMGB1 regulates pyroptosis in neuroblastoma remains unknown. Here, we showed that HMGB1 showed ubiquitous higher expression in SH-SY5Y cells and clinical tumors, and was positively correlated with the risk factors of patients with neuroblastoma. Knockdown of GSDME or pharmacological inhibition of caspase-3 blocked pyroptosis and cytosolic translocation of HMGB1. Moreover, knockdown of HMGB1 inhibited cisplatin (DDP) or etoposide (VP16)-induced pyroptosis by decreasing GSDME-NT and cleaved caspase-3 expression, resulting in cell blebbing and LDH release. Knockdown of HMGB1 expression increased the sensitivity of SH-SY5Y cells to chemotherapy and switched pyroptosis to apoptosis. Furthermore, the ROS/ERK1/2/caspase-3/GSDME pathway was found to be functionally connected with DDP or VP16-induced pyroptosis. Hydrogen peroxide (H2O2, a ROS agonist) and EGF (an ERK agonist) promoted the cleavage of GSDME and caspase-3 in DDP or VP16 treatment cells, both of which were inhibited by HMGB1 knockdown. Importantly, these data were further supported by the in vivo experiment. Our study suggests that HMGB1 is a novel regulator of pyroptosis via the ROS/ERK1/2/caspase-3/GSDME pathway and a potential drug target for therapeutic interventions in neuroblastoma.
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Critical bone defects caused by extensive excision of malignant bone tumor and the probability of tumor recurrence due to residual tumor cells make malignant bone tumor treatment a major clinical challenge. The present therapeutic strategy concentrates on implanting bone substitutes for defect filling but suffers from failures in both enhancing bone regeneration and inhibiting the growth of tumor cells. Herein, Cu and Mn-doped borosilicate nanoparticles (BSNs) were developed for syncretic bone repairing and anti-tumor treatment, which can enhance bone regeneration through the osteogenic effects of Cu2+ and Mn3+ ions and meanwhile induce tumor cells apoptosis through the hydroxyl radicals produced by the Fenton-like reactions of Cu2+ and Mn3+ ions. In vitro study showed that both osteogenic differentiation of BMSCs and angiogenesis of endothelial cells were promoted by BSNs, and consistently the critical bone defects of rats were efficiently repaired by BSNs through in vivo evaluation. Meanwhile, BSNs could generate hydroxyl radicals through Fenton-like reactions in the simulated tumor microenvironment, promote the generation of intracellular reactive oxygen species, and eventually induce tumor cell apoptosis. Besides, subcutaneous tumors of mice were effectively inhibited by BSNs without causing toxic side effects to normal tissues and organs. Altogether, Cu and Mn-doped BSNs developed in this work performed dual functions of enhancing osteogenesis and angiogenesis for bone regeneration, and inhibiting tumor growth for chemodynamic therapy, thus holding a great potential for syncretic bone repairing and anti-tumor therapy.
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Gallium oxide as a novel electrode material has attracted attention because of its high stability and conductivity. In addition, Ga2O3 will be converted to Ga during the charge and discharge process, and the self-healing behavior of Ga can improve the cycling stability. In this paper, we synthesized Ga2O3 nanoparticles with a size of about 4 nm via a facile sol-gel method. Meanwhile, we employed three types of carbon materials (reduced graphene oxide, mesoporous carbon nanofiber arrays, and carbon nanotubes) to avoid the aggregation of Ga2O3 nanoparticles and improve the conductivity of Ga2O3 during the discharge/charge process as well. Among the three samples, the deactivating defective sites and special carbon matrix of reduced graphene oxide can provide more attachment points for Ga ions, so the Ga2O3 nanoparticles can be more closely and uniformly distributed on rGO. Benefitting from the perfect combination of reduced graphene oxide sheets and Ga2O3 nanoparticles, a stable capacity of the Ga2O3/rGO electrode can be maintained at 411 mA h g-1 at a current density of 1000 mA g-1 after 600 cycles. We believe that this work provides a novel and efficient way to improve the electrochemical stability of Li-ion batteries.
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PURPOSE: To explore the regulatory effect of HMGB1 upon hypoxia-induced mitochondrial biogenesis in pancreatic cancer PANC1/CFPAC1 cells. METHODS: After a down-regulation of HMGB1 expression by lentivirus-mediated RNAi, the effect of knocking down HMGB1 on hypoxia-induced mitochondrial biogenesis was examined. NRF-1/TFAM expression, mtDNA copy number, ATP content and mitochondrial number/morphology in hypoxia-treated pancreatic cancer cells were detected by quantitative reverse transcription-polymerase chain reaction (qRT-PCR), Western blot, mtDNA and ATP assay kits and electron microscopy, respectively. Cell proliferation was measured by MTS assay. And protein and acetylation levels of PGC-1α and SIRT1 activity were detected by Western blot, immunoprecipitation (IP) and SIRT1 activity kit. RESULTS: Hypoxia enhanced the expressions of NRF-1/TFAM, boosted mtDNA copy number and ATP content and increased the number of mitochondria in pancreatic cancer cells while induction was suppressed by a knockdown of HMGB1. Knocking down HMGB1 expression lowered hypoxia-induced PGC-1α/SIRT1 expression and activity, phosphorylation of AMPK. PGC-1α over-expression by a plasmid transfection failed to boost mtDNA copy number or ATP content in HMGB1-knockdown cells. A knockdown of HMGB1 attenuated hypoxia with AICAR (an AMPK activator)-induced expression of NRF-1, TFAM, PGC-1α, SIRT1 and the proteins of complexes â & â ¢ and reduced the acetylation level of PGC-1α/SIRT1 activity. Additionally, SRT1720 (a SIRT1 activator)-induced elevation in SIRT1 activity boosted hypoxia-induced PGC-1α deacetylation, except in HMGB1-knockdown cells. CONCLUSION: As a novel regulator of mitochondrial biogenesis via AMPK/SIRT1 pathway under hypoxia, HMGB1 may become a potential drug target for therapeutic interventions in pancreatic cancer.
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A Ga/Ga2O3@C dodecahedron composite with a high specific capacity of about 542 mA h g-1 after 200 cycles at the current density of 1000 mA g-1 was synthesized by one-step hydrogen reduction. This hierarchical homogeneous structure combined the Ga, Ga2O3 and carbon frameworks (from Ga-MOF) to exhibit excellent electrochemical performance.
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BACKGROUND: Sodium/iodide symporter (NIS)-mediated iodide uptake plays an important physiological role in regulating thyroid gland function, as well as in diagnosing and treating Graves' disease and thyroid cancer. High-mobility group box 1 (HMGB1), a highly conserved nuclear protein, is a positive regulator of autophagy conferring resistance to chemotherapy, radiotherapy and immunotherapy in cancer cells. Here the authors intended to identify the role of HMGB1 in Hank's balanced salt solution (HBSS)-induced autophagy, explore NIS protein degradation through a autophagy-lysosome pathway in thyroid cancer cells and elucidate the possible molecular mechanisms. METHODS: Immunohistochemical staining and reverse transcription-polymerase chain reaction (RT-PCR) were performed for detecting the expression of HMGB1 in different tissues. HMGB1 was knocked down by lentiviral transfection in FTC-133/TPC-1 cells. Autophagic markers LC3-II, p62, Beclin1 and autophagosomal formation were employed for evaluating HMGB1-mediated autophagy in HBSS-treated cells by Western blot, immunofluorescence and electron microscopy. Western blot, quantitative RT-PCR and gamma counter analysis were performed for detecting NIS expression and iodide uptake in HMGB1-knockdown cells after different treatments. The reactive oxygen species (ROS) level, ROS-mediated LC3-II expression and HMGB1 cytosolic translocation were detected by fluorospectrophotometer, flow cytometry, Western blot and immunofluorescence. HMGB1-mediated AMPK, mTOR and p70S6K phosphorylation (p-AMPK, p-mTOR & p-p70S6K) were detected by Western blot. Furthermore, a nude murine model with transplanted tumor was employed for examining the effect of HMGB1-mediated autophagy on imaging and biodistribution of 99mTcO4-. NIS, Beclin1, p-AMPK and p-mTOR were detected by immunohistochemical staining and Western blot in transplanted tumor samples. RESULTS: HMGB1 was a critical regulator of autophagy-mediated NIS degradation in HBSS-treated FTC-133/TPC-1 cells. And HMGB1 up-regulation was rather prevalent in thyroid cancer tissues and closely correlated with worse overall lymph node metastasis and clinical stage. HMGB1-knockdown dramatically suppressed autophagy, NIS degradation and boosted iodide uptake in HBSS-treated cells. Moreover, HBSS enhanced ROS-sustained autophagy and promoted the cytosolic translocation of HMGB1. A knockdown of HMGB1 suppressed LC3-II conversion and NIS degradation via an AMPK/mTOR-dependent signal pathway through a regulation of ROS generation, rather than ATP. Furthermore, these data were further supported by our in vivo experiment of xenografts formed by HMGB1 knockdown cells reverting the uptake of 99mTcO4- as compared with control shRNA-transfected cells in hunger group. CONCLUSIONS: Acting as a critical regulator of autophagy-mediated NIS degradation via ROS/AMPK/mTOR pathway, HMGB1is a potential intervention target of radioiodine therapy in thyroid cancer.
Subject(s)
Autophagy/genetics , HMGB1 Protein/genetics , Iodine Radioisotopes/pharmacology , Symporters/genetics , Thyroid Neoplasms/radiotherapy , Animals , Autophagosomes/drug effects , Autophagy/radiation effects , Cell Line, Tumor , Gene Expression Regulation, Neoplastic/radiation effects , Gene Knockdown Techniques , Heterografts , Humans , Iodine Radioisotopes/metabolism , Mice , Microtubule-Associated Proteins/genetics , Proteolysis/radiation effects , Reactive Oxygen Species/metabolism , Symporters/chemistry , Thyroid Gland/radiation effects , Thyroid Neoplasms/genetics , Thyroid Neoplasms/pathologyABSTRACT
In this work, we synthesized a novel UIO-67@Se@PANI composite cathode material for Li-Se battery applications. Zr-MOFs (metal organic frameworks) were used as a support and a PANI (polyaniline) layer was employed as the coating. UIO-67@Se@PANI was expected to be one of the candidates for Li-Se batteries, with a high specific capacity of 248.3 mA h g-1 at 1C (1C = 675 mA g-1) after 100 cycles. In particular, stable capacities of 203.1 and 167.6 mA h g-1 were received after 100 cycles at high rates of 2C and 5C, respectively. To explain such a good electrochemistry performance of the composite cathode material, multiple characterization methods were carried out. And that can be attributed to the sandwich-like structure of the UIO-67@Se@PANI composite and the fact that UIO-67 can provide unsaturated sites to tether the selenium effectively and the PANI layer can improve the electronic conductivity of the whole electrode significantly.
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Ferroptosis is emerging as a new form of regulated cell death driven by oxidative injury promoting lipid peroxidation in an iron-dependent manner. High mobility group box 1 (HMGB1) plays an important role in leukemia pathogenesis and chemotherapy resistance. The mechanisms of ferroptosis in tumor pathogenesis and treatment have been a recent research focus but the role of HMGB1 in regulating ferroptosis especially in leukemia still remains largely unknown. Here, we shown that HMGB1 is a critical regulator of eratin-induced ferroptosis in HL-60 cell line expressing NRASQ61L (HL-60/NRASQ61L). Erastin enhanced ROS levels, thereby promoting cytosolic translocation of HMGB1 and enhancing cell death. Knockdown of HMGB1 decreased erastin-induced ROS generation and cell death in an iron-mediated lysosomal pathway in HL-60/NRASQ61L cells. Knockdown of HMGB1 or rat sarcoma (RAS), or pharmacological inhibition of JNK and p38 decreased TfR1 levels in HL-60/NRASQ61L cells. Importantly, these data were further supported by our in vivo experiment, in which xenografts formed by HMGB1 knockdown HL-60/NRASQ61L cells had lower PTGS2 and TfR1 expression than that in control mice. Taken together, these results suggest that HMGB1 is a novel regulator of ferroptosis via the RAS-JNK/p38 pathway and a potential drug target for therapeutic interventions in leukemia.
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Bi2S3 is a promising negative electrode material for lithium storage owing to its high theoretical capacity. Nevertheless, the capacity of Bi2S3 decays very rapidly upon Li cycling. Here, Bi2S3 and Bi2S3/C were successfully synthesized by a novel route. Sulfur powder as a kind of sulfur source reacted with a metal organic framework based on bismuth and trimesinic acid-Bi(BTC)(DMF)·DMF·(CH3OH)2 (denoted as Bi-BTC). Trimesic acid further acted as a new type of carbon source to synthesize the Bi2S3/C composite. The particle sizes of the composite were smaller than those of pure Bi2S3, showing the suppression of Bi2S3 aggregation. Charge-discharge performance and cyclability for both the Bi2S3 and Bi2S3/C composites in lithium-ion batteries were measured. Specifically, the specific capacities of Bi2S3/C and Bi2S3 reached 765 and 603 mA h g-1, respectively, at 100 mA g-1 after 100 cycles. Because of its high capacity and excellent cycle life, Bi2S3/C is a promising energy storage material.
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Ataxia-telangiectasia (A-T) is an infrequent autosomal recessive disorder that involves multiple systems and is characterized by progressive cerebellar ataxia, oculocutaneous telangiectasias, radiosensitivity, immune deficiency with recurrent respiratory infections, and a tendency to develop lymphoid malignancies. A-T is caused by mutations in the ATM gene, with >1,000 mutations reported to date and gradually increasing in number. Patients with A-T have an increased incidence of cancers. The aim of the present study was to retrospectively review the case of a patient who presented at the age of 5 years with cerebellar ataxia without telangiectasia, and was diagnosed with Burkitt leukemia by bone marrow biopsy and molecular testing at the age of 7 years at the Xiangya Hospital of Central South University (Changsha, China). The patient received chemotherapy with the pediatric CCCG-BNHL-2015 regimen (R4 group) and achieved a complete remission after 2 courses. However, recurrent respiratory infections and thrombosis occurred during chemotherapy. The diagnosis of A-T was confirmed by uncovering two variants of the ATM gene, including c.742C>T (p.R248X; rs730881336) in exon 7 and c.6067-c.6068 ins GAGGGAAGAT in exon 41 by whole-exome sequencing. Unfortunately, the patient's parents refused follow-up treatment and he succumbed to recurrent severe infections 4 months after the diagnosis of Burkitt leukemia. The diagnosis of A-T may be challenging, as its phenotype can be incomplete early in the course of the disease. Detailed medical history, characteristic clinical manifestations and increasingly developed exome sequencing techniques may be helpful in diagnosing this rare disease. Management should be based on multidisciplinary guidance and other treatment options must be investigated in the future.
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Differentiation therapy based on all-trans-retinoic acid (ATRA) and arsenic trioxide (ATO) for the treatment of acute promyelocytic leukemia (APL) is complicated by the development of differentiation syndrome (DS), which can be fatal. We examined the role of HMGB1 (high-mobility group box 1) in DS using both in vitro and in vivo models. HMGB1 and the pro-inflammatory cytokines IL-1ß and TNF-α were gradually released from NB4 and HL-60 cells treated with ATRA and/or ATO. Similarly, higher serum HMGB1 levels positively correlated with the clinical status of DS patients. Exogenous HMGB1 promoted rapid release of IL-1ß and TNF-α as well as elevated expression of ICAM-1, without altering cell differentiation. Exogenous HMGB1 also enhanced pulmonary infiltration and up-regulated ICAM-1 expression in the ATRA-treated DS mouse. Pharmacological inhibition or depletion of MEK1/2 reduced the cytokine levels and suppressed expression of ICAM-1 and the adhesion of HMGB1-treated NB4 cells to endothelial cells, implicating MEK/ERK signaling in the response to HMGB1 during DS. Treatment with a HMGB1-neutralizing antibody reduced secretion of TNF-α and IL-1ß, arrested the elevation of ICAM-1 and blunted the activation of ERK1/2 in ATRA-induced NB4 cells. The HMGB1-neutralizing antibody also decreased ICAM-1 expression and reduced mortality in ATRA-treated DS model mice. These findings demonstrate that released HMGB1 is central to DS, and that targeting HMGB1 may be of therapeutic value in the treatment of DS.
Subject(s)
Cell Differentiation , HMGB1 Protein/metabolism , Leukemia, Promyelocytic, Acute/metabolism , Leukemia, Promyelocytic, Acute/pathology , MAP Kinase Signaling System , Adolescent , Animals , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Cell Adhesion Molecules/genetics , Cell Adhesion Molecules/metabolism , Cell Differentiation/drug effects , Cell Differentiation/genetics , Cell Line, Tumor , Cell Survival , Child , Child, Preschool , Cytokines/metabolism , Disease Models, Animal , Female , Gene Expression Regulation, Neoplastic , HMGB1 Protein/genetics , Humans , Infant , Inflammation Mediators/metabolism , Leukemia, Promyelocytic, Acute/drug therapy , Leukemia, Promyelocytic, Acute/genetics , Male , Neoplasm Grading , Neoplasm Staging , Remission Induction , Xenograft Model Antitumor AssaysABSTRACT
Chemoresistance of leukemia constitutes a great challenge for successful treatment of leukemia. Autophagy has recently attracted increasing attention for its role in conferring resistance to various conventional anti-neoplastic regiments. In the present study, the authors showed that WAVE1, a member of WASP family verprolin-homologous proteins, is a critical regulator of chemoresistance during autophagy. It is positively correlated with clinical status in pediatric acute myeloblastic leukemia (AML) and leukemia cell lines. The knockdown of WAVE1 expression decreased autophagy was accompanied by an upregulation of autophagic marker microtubule-associated protein light chain 3 (LC3)-â ¡, a degradation of SQSTM1/sequestosome 1 (p62) and the formation of autophagosomes. Moreover, a suppression of WAVE1 expression increased the sensitivity of leukemia cells to chemotherapy and apoptosis, and depletion of WAVE1 expression promoted the translocation of Bcl-2 from mitochondria into the cytoplasm. In addition, a knockdown of PI3K-â ¢ expression significantly inhibited WAVE1-mediated autophagy. Furthermore, suppression of WAVE1 expression blocked the interactions between Beclin1 and PI3K-â ¢ and the disassociation of Beclin1-Bcl-2 during enhanced autophagy. The above results suggested that WAVE1 is a critical pro-autophagic protein capable of enhancing cell survival and regulating chemoresistance in leukemia cells potentially through the Beclin1/Bcl-2 and Beclin1/PI3K-â ¢ complex-dependent pathways.
Subject(s)
Down-Regulation , Drug Resistance, Neoplasm , Leukemia, Myeloid, Acute/metabolism , Wiskott-Aldrich Syndrome Protein Family/genetics , Wiskott-Aldrich Syndrome Protein Family/metabolism , A549 Cells , Adolescent , Apoptosis , Autophagy , Beclin-1/metabolism , Cell Line, Tumor , Child , Child, Preschool , Female , Gene Expression Regulation, Leukemic , Gene Knockdown Techniques , HL-60 Cells , Humans , Infant , K562 Cells , Leukemia, Myeloid, Acute/genetics , Male , Phosphatidylinositol 3-Kinases/metabolism , Proto-Oncogene Proteins c-bcl-2/metabolism , Signal TransductionABSTRACT
Acute promyelocytic leukemia (APL) results from a blockade of granulocyte differentiation during the promyelocytic stage. As a fusion protein of promyelocytic leukemia (PML) and retinoic acid receptor-α (RARα), PML-RARα oncoprotein is degraded through the differentiation of all-trans retinoic acid (ATRA)-induced cells. Here reactive oxygen species (ROS) and high-mobility group box 1 (HMGB1) were proven essential for the differentiation of APL cells. A down-regulation of ROS by ROS quencher (NAC) blocked the differentiation of APL cell line NB4 while an over-expression of ROS by superoxide dismutase-1 (SOD1) RNA interference (RNAi) increased cell differentiation. HMGB1 was vital for the differentiation of ROS-mediated NB4 cells and its up-regulation promoted ATRA-induced autophagy and the degradation of PML-RARα. Furthermore, ATRA treatment elevated the levels of ROS, enhanced autophagic flux and thereby promoted cytosolic translocation of HMGB1. HMGB1 regulated the interactions between ubiquitin-binding adaptor protein p62/SQSTM and PML-RARα so as to affect the degradation of PML-RARα during ATRA-induced autophagy. Also a depletion of p62/SQSTM1 expression inhibited HMGB1-mediated PML-RARα degradation and cell differentiation. The overall results suggested that HMGB1 is an essential regulator of ROS-induced cell differentiation. And it may become a potential drug target for therapeutic intervention of APL.
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OBJECTIVE: To investigate the feasibility of a novel molecular probe of Zn-DPA-PSS794 to monitor the efficiency of doxorubicin to ovarian cancer and compare with Cy5.5-annexin V. METHODS: Efficiency of doxorubicin to OVCAR-8 cells in vitro was measured by MTT assay and flow cytometry. The in vivo studies were performed on an OVCAR-8 xenograft tumor model. Mice were divided into a control group and a treatment group. Each group was divided into 2 subgroups, DPA and annexin V. In the treatment group, the mice were treated with doxorubicin for 2 doses. All mice were performed optical imaging by Zn-DPA-PSS794 or Cy5.5-annexin V, respectively and then sacrificed. The tumor was separated and stained by HE. The expression of caspase-3 protein was measured by Western blot. RESULTS: The IC50 of doxorubicin to OVCAR-8 was 6 µmol/L. The percentage of apoptosis and dead cells was 35% after doxorubicin treatment. In the optical image, photons accumulated in the tumor either by Zn-DPA-PSS794 or Cy 5.5-annexin V in the treatment group. That was negative in the control group. The fluorescence intensity had significant difference between the 2 groups(P<0.001). The nuclei were big and stained with deep color after the cells were stained with HE. The caspase-3 expression was high in the treatment group, while it was low in the control group. CONCLUSION: Zn-DPA-PSS794 as a probe used by optical imaging can monitor the efficiency of doxorubicin to OVCAR-8 xenograft tumor, which is similar to Cy5.5-annexin V.