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1.
Gastric Cancer ; 27(1): 118-130, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37906316

RESUMO

BACKGROUND: We conducted a trial to evaluate the efficacy and safety of nivolumab and paclitaxel as second-line therapy for immune-related biomarker-enriched advanced gastric cancer (AGC). METHODS: This open-label, single-arm, phase Ib/II study was a part of multi-institutional, biomarker-integrated umbrella study conducted in Korea. In phase Ib, patients received nivolumab (3 mg/kg) on Days 1 and 15 and paclitaxel (dose level 1, 70 mg/m2 or dose level 2, 80 mg/m2) on Days 1, 8, 15 every four weeks. In phase II, patients with Epstein-Barr virus-related, deficient mismatch repair or programmed cell death-ligand-1-positive AGC were enrolled. The primary endpoints were recommended phase II dose (RP2D, phase Ib) and progression-free survival (PFS, phase II). Secondary endpoints included objective response rate (ORR), overall survival (OS), safety, and exploratory biomarker analysis. RESULTS: Dose level 2 was selected as RP2D. In phase II, 48 patients were enrolled. The median PFS and OS were 3.9 and 11.2 months, respectively. The ORR was 23.3%, and the median response duration was 16.7 months. Grade 3 or higher treatment-related adverse events, mainly neutropenia, occurred in 20 patients (41.7%). Targeted sequencing revealed that patients with RTK/RAS pathway alterations or the HLA-A02 supertype had better survival. Patients with elevated baseline interleukin-1 receptor antagonist levels had worse survival. CONCLUSIONS: Although the study did not meet its primary end point, nivolumab and paclitaxel for AGC demonstrated a durable response with manageable toxicity profiles. Genomic analysis or plasma cytokine analysis may provide information for the selection of patients who would benefit more from immunotherapy combined with chemotherapy.


Assuntos
Infecções por Vírus Epstein-Barr , Neoplasias Gástricas , Humanos , Protocolos de Quimioterapia Combinada Antineoplásica , Biomarcadores , Herpesvirus Humano 4 , Imunoterapia , Nivolumabe/uso terapêutico , Nivolumabe/efeitos adversos , Paclitaxel
2.
Bioelectromagnetics ; 42(5): 371-383, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34082485

RESUMO

Static magnetic field (SMF) can alter cell fate decisions in many ways. However, the effects of SMF on cancer stem cells (CSCs) are little-known. In this particular study, we evaluate the biological effect of moderate-intensity SMF on osteosarcoma stem cells (OSCs) and try to clarify the underlying mechanisms of action. First, we demonstrated that prolonged exposure to SMF induced the proliferation and tumorsphere formation in K7M2 and MG63 OSCs. Moreover, SMF promoted the release of ferrous iron (Fe2+ ) and provoked reactive oxygen species (ROS) in OSCs. Interestingly, SMF evidently triggered the autophagic degradation of ferritin, which is characterized by the activation of microtubule-associated protein 1 light chain 3 (LC3) and nuclear receptor co-activator 4 (NCOA4), and downregulation of ferritin heavy chain 1 (FTH1) in OSCs. Particularly, the colony-forming ability of K7M2 OSCs promoted by SMF was obviously abolished by using a small interfering RNA (siRNA) against NCOA4. Finally, treatment of the tumor-bearing mice with SMF did not affect the tumor volume or tumor mass, nor pulmonary metastasis of K7M2 OSCs, but the SMF-treated K7M2 OSCs caused a preference of pulmonary metastasis in a mouse model, which suggested that SMF might induce the metastatic characteristic of OSCs. Consequently, this paper demonstrates for the first time that the cumulative SMF exposure promoted the self-renewal ability of OSCs via autophagic degradation of ferritin, implying that ferritinophagy may be a potential molecular target for cancer. © 2021 Bioelectromagnetics Society.


Assuntos
Neoplasias Ósseas , Osteossarcoma , Animais , Ferritinas , Campos Magnéticos , Camundongos , Células-Tronco
3.
Appl Microbiol Biotechnol ; 100(17): 7565-75, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27115755

RESUMO

The 14-amino acid (IEGPTLRQWLAARA) thrombopoietin mimetic peptide (TMP) shares no sequence homology with native thrombopoietin (TPO). When dimerized, it displays a high-binding affinity for the TPO receptor and has equipotent bioactivity with recombinant human TPO (rhTPO) in stimulating proliferation and maturation of megakaryocytes in vitro. However, TMP is limited for clinical usage because of its short half-life in vivo. In this study, fusion proteins that composed of tandem dimer of TMP (dTMP) genetically fused at the C- or N-terminus of human serum albumin (HSA) were separately expressed in Chinese hamster ovary (CHO) cells. In vitro bioactivity assays showed that purified fusion proteins promoted the proliferation of megakaryocytes in a dose-dependent manner and activated signal transducer and activator of transcription (STAT) pathway in TPO receptor-dependent manner. Following subcutaneous administration, both HSA-dTMP and dTMP-HSA significantly elevated peripheral platelet counts in normal mice in a dose-dependent manner. In addition, fusion with HSA successfully prolonged dTMP half-life in mice. However, when HSA was fused at the C-terminus of dTMP, the bioactivity of dTMP-HSA was about half of that of HSA-dTMP. In conclusion, these results suggested that HSA/dTMP fusion proteins might be potential drugs for thrombocytopenia and, when HSA was fused at the N-terminus of dTMP, the fusion protein had a higher activity.


Assuntos
Proliferação de Células/efeitos dos fármacos , Megacariócitos/metabolismo , Peptídeos/genética , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/farmacologia , Albumina Sérica/genética , Animais , Células CHO , Linhagem Celular , Cricetinae , Cricetulus , Ativação Enzimática/efeitos dos fármacos , Feminino , Expressão Gênica , Humanos , Masculino , Megacariócitos/efeitos dos fármacos , Camundongos , Peptídeos/metabolismo , Contagem de Plaquetas , Proteínas Recombinantes de Fusão/biossíntese , Fatores de Transcrição STAT/metabolismo , Albumina Sérica/biossíntese , Albumina Sérica/metabolismo , Trombocitopenia/tratamento farmacológico
4.
J Asian Nat Prod Res ; 17(4): 415-9, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25363682

RESUMO

A new eremophilane norsesquiterpenoid (1), together with a known eremophilane sesquiterpenoid (2), was isolated from the leaves of Ligularia virgaurea. The structure of 1 was elucidated by a combination of spectroscopic analysis (IR, 1D NMR, 2D NMR, and HR-ESI-MS), and its absolute configuration was determined by a single-crystal X-ray diffraction experiment (with copper radiation). The known compound 2 was identified by comparison of its physical and spectral data with those reported in the literature. Compound 1 was assayed for its cytotoxic activities against human cervical carcinoma cell (HeLa) and human small cell lung cancer cell (NCI-446) lines.


Assuntos
Antineoplásicos Fitogênicos/isolamento & purificação , Asteraceae/química , Sesquiterpenos/isolamento & purificação , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia , Cristalografia por Raios X , Ensaios de Seleção de Medicamentos Antitumorais , Células HeLa , Humanos , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Sesquiterpenos/química , Sesquiterpenos/farmacologia
5.
Eur J Pharmacol ; 967: 176364, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38316249

RESUMO

Osteocytes, as mechanosensitive cells residing within bone tissue, hold a pivotal role in averting the occurrence and progression of osteoporosis. The apoptosis of osteocytes induced by unloading is one of the contributing factors to osteoporosis, although the underlying molecular mechanisms have not been fully elucidated. PTH 1-34 is known to promote bone formation and inhibit bone loss by targeting osteoblasts and osteocytes. However, it is not known whether PTH 1-34 can inhibit osteocyte apoptosis under unloading conditions and the molecular mechanisms involved. In this study, we employed a Random Positioning Machine (RPM) to emulate unloading conditions and cultured MLO-Y4 osteocyte-like cells, in order to unravel the mechanisms through which PTH 1-34 constrains osteocyte apoptosis amidst unloading circumstances. Our findings revealed that PTH 1-34 activated autophagy while suppressing endoplasmic reticulum stress by curtailing the generation of reactive oxygen species (ROS) in MLO-Y4 osteocyte-like cells during unloading conditions. By shedding light on the osteoporosis triggered by skeletal unloading, this study contributes vital insights that may pave the way for the development of pharmacological interventions.


Assuntos
Osteócitos , Osteoporose , Apoptose , Autofagia , Osteoblastos , Hormônio Paratireóideo , Animais , Camundongos
6.
Artigo em Inglês | MEDLINE | ID: mdl-36833823

RESUMO

The hypoxia pathway not only regulates the organism to adapt to the special environment, such as short-term hypoxia in the plateau under normal physiological conditions, but also plays an important role in the occurrence and development of various diseases such as cancer, cardiovascular diseases, osteoporosis. Bone, as a special organ of the body, is in a relatively low oxygen environment, in which the expression of hypoxia-inducible factor (HIF)-related molecules maintains the necessary conditions for bone development. Osteoporosis disease with iron overload endangers individuals, families and society, and bone homeostasis disorder is linked to some extent with hypoxia pathway abnormality, so it is urgent to clarify the hypoxia pathway in osteoporosis to guide clinical medication efficiently. Based on this background, using the keywords "hypoxia/HIF, osteoporosis, osteoblasts, osteoclasts, osteocytes, iron/iron metabolism", a matching search was carried out through the Pubmed and Web Of Science databases, then the papers related to this review were screened, summarized and sorted. This review summarizes the relationship and regulation between the hypoxia pathway and osteoporosis (also including osteoblasts, osteoclasts, osteocytes) by arranging the references on the latest research progress, introduces briefly the application of hyperbaric oxygen therapy in osteoporosis symptoms (mechanical stimulation induces skeletal response to hypoxic signal activation), hypoxic-related drugs used in iron accumulation/osteoporosis model study, and also puts forward the prospects of future research.


Assuntos
Osteoclastos , Osteoporose , Humanos , Osteoblastos , Hipóxia/metabolismo , Osteoporose/metabolismo , Ferro/metabolismo
7.
Biomed Pharmacother ; 168: 115748, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37865995

RESUMO

Nuclear factor erythroid-2-related factor 2 (Nrf2) plays an important role in maintaining cellular homeostasis, as it suppresses cell damage caused by external stimuli by regulating the transcription of intracellular defense-related genes. Accumulating evidence has highlighted the crucial role of reduction-oxidation (REDOX) imbalance in the development of bone-related diseases. Nrf2, a transcription factor linked to nuclear factor-erythrocyte 2, plays a pivotal role in the regulation of oxidative stress and induction of antioxidant defenses. Therefore, further investigation of the mechanism and function of Nrf2 in bone-related diseases is essential. Considerable evidence suggests that increased nuclear transcription of Nrf2 in response to external stimuli promotes the expression of intracellular antioxidant-related genes, which in turn leads to the inhibition of bone remodeling imbalance, improved fracture recovery, reduced occurrence of osteoarthritis, and greater tumor resistance. Certain natural extracts can selectively target Nrf2, potentially offering therapeutic benefits for osteogenic arthropathy. In this article, the biological characteristics of Nrf2 are reviewed, the intricate interplay between Nrf2-regulated REDOX imbalance and bone-related diseases is explored, and the potential preventive and protective effects of natural products targeting Nrf2 in these diseases are elucidated. A comprehensive understanding of the role of Nrf2 in the development of bone-related diseases provides valuable insights into clinical interventions and can facilitate the discovery of novel Nrf2-targeting drugs.


Assuntos
Antioxidantes , Doenças Ósseas , Fator 2 Relacionado a NF-E2 , Humanos , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Antioxidantes/metabolismo , Doenças Ósseas/tratamento farmacológico , Regulação da Expressão Gênica , Fator 2 Relacionado a NF-E2/metabolismo , Oxirredução , Estresse Oxidativo
8.
Prog Biophys Mol Biol ; 177: 14-23, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36240898

RESUMO

With the widespread use of static magnetic fields (SMFs) in medicine, it is imperative to explore the biological effects of SMFs and the mechanisms underlying their effects on biological systems. The presence of magnetic materials within cells and organisms could affect various biological metabolism and processes, including stress responses, proliferation, and structural alignment. SMFs were generally found to be safe at the organ and organism levels. However. human subjects exposed to strong SMFs have reported side effects. In this review, we combined the magnetic properties of biological samples to illustrate the mechanism of action of SMFs on biological systems from a biophysical point of view. We suggest that the mechanisms of action of SMFs on biological systems mainly include the induction of electric fields and currents, generation of magnetic effects, and influence of electron spins. An electrolyte flowing in a static magnetic field generates an induced current and an electric field. Magnetomechanical effects include orientation effects upon subjecting biological samples to SMFs and movement of biological samples in strong field gradients. SMFs are thought to affect biochemical reaction rates and yields by influencing electron spin. This paper helps people how can harness the favorable biological effects of SMFs.


Assuntos
Campos Magnéticos , Humanos , Biofísica
9.
J Orthop Translat ; 38: 126-140, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36381248

RESUMO

Objective: With the deepening of magnetic biomedical effects and electromagnetic technology, some medical instruments based on static magnetic field (SMF) have been used in orthopedic-related diseases treatment. Studies have shown SMF could combat osteoporosis by regulating the differentiation of mesenchymal stem cells (MSCs), osteoblast and osteoclast. With the development of nanotechnology, iron oxide nanoparticles (IONPs) have been reported to regulate the process of bone anabolism. As for SMF combined with IONPs, studies indicated osteogenic differentiation of MSCs were promoted by the combination of SMF and IONPs. However, there are few reports on the effects of SMF combined with IONPs on osteoclast. Herein, the purpose of this study was to investigate the effects of high static magnetic field (HiSMF) combined with IONPs on unloading-induced bone loss in vivo and osteoclastic formation in vitro, and elucidated the potential molecular mechanisms. Methods: In vivo, C57BL/6 â€‹J male mice were unloaded via tail suspension or housed normally. The hindlimb of mice were fixed and exposed to 1-2 â€‹T SMF for 1 â€‹h every day, 10 â€‹mg/kg of Ferumoxytol or saline were injected by tail vein once a week, last for 4 weeks. Bone microstructure, mechanical properties, and osteoclastogenesis were examined respectively. In vitro, the RAW264.7 â€‹cells were used to assess the effects of 1-2 â€‹T SMF combined with IONPs in osteoclastogenesis. The iron content was detected by atomic absorption spectrometry and Prussian blue staining. DCFH-DA and MitoSOX™ fluorescence staining were used to assess oxidative stress levels. NF-κB and MAPK signaling pathways were examined by western blot assay. Results: In vivo, the results showed 1-2 â€‹T SMF and IONPs prevented the damage to bone microstructure and improved the mechanical properties, diminished the number of osteoclasts in unloaded mice, 1-2 â€‹T SMF combined with IONPs was found more effective. The iron content in the liver and spleen was reduced by the combination of 1-2 â€‹T SMF and IONPs, enhancing iron levels in the femur. In vitro, osteoclast formation was inhibited by 1-2 â€‹T SMF and IONPs treatment, and 1-2 â€‹T SMF combined with IONPs had a more pronounced effect. Moreover, iron uptake of IONPs in osteoclast was reduced to 1-2 â€‹T SMF exposure. Oxidative stress levels were decreased in osteoclast differentiation under 1-2 â€‹T SMF combined with IONPs treatment. Molecularly, the expression of NF-κB and MAPK signaling pathways were inhibited under 1-2 â€‹T SMF combined with IONPs in osteoclastogenesis. Conclusions: Synthetically, our research illustrated 1-2 â€‹T SMF combined with IONPs prevented unloading-induced bone loss by regulating iron metabolism in osteoclastogenesis.Translational potential of this article: As a non-invasive alternative therapy, some medical instruments based on SMF have been used for orthopedic-related diseases treatment for their portability, cheapness and safety. Ferumoxytol (Feraheme™), the first FDA-approved IONP drug for the treatment of iron deficiency anemia, has been also adapted in translational research for osteoporosis. Based on the above-mentioned two points, we found the synergistic effects of SMF and Ferumoxytol for treatment of experimental osteoporosis. These results show translational potentials for clinical application.

10.
J Clin Oncol ; 41(27): 4394-4405, 2023 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-37364218

RESUMO

PURPOSE: Trastuzumab-containing chemotherapy is the recommended first-line regimen for human epidermal growth factor receptor 2 (HER2)-positive advanced gastric or gastroesophageal junction (G/GEJ) cancer. We evaluated the safety and efficacy of trastuzumab combined with ramucirumab and paclitaxel as second-line treatment for HER2-positive G/GEJ cancer. PATIENTS AND METHODS: Patients with HER2-positive advanced G/GEJ cancer who progressed after first-line treatment with trastuzumab-containing chemotherapy were enrolled from five centers in the Republic of Korea. Patients were administered a 28-day cycle of trastuzumab (once on days 1, 8, 15, and 22: 2 mg/kg followed by 4 mg/kg loading dose), ramucirumab (once on days 1 and 15: 8 mg/kg), and paclitaxel (once on days 1, 8, and 15: dose level 1, 80 mg/m2; or dose level -1, 70 mg/m2). Phase II was conducted with the recommended phase II dose (RP2D). Primary end points were determination of RP2D during phase Ib and investigator-assessed progression-free survival (PFS) in patients treated with RP2D. RESULTS: Dose-limiting toxicity at dose level 1 was not documented during phase Ib, and a full dose combination was selected as the RP2D. Among 50 patients with a median follow-up duration of 27.5 months (95% CI, 17.4 to 37.6), median PFS and overall survival were 7.1 months (95% CI, 4.8 to 9.4) and 13.6 months (95% CI, 9.4 to 17.7), respectively. Objective response rate was 54% (27 of 50, including one complete response), and disease control rate was 96% (48 of 50). Loss of HER2 expression was observed in 34.8% (8 of 23) patients after first-line treatment, and no definite association between HER2 expression and the outcome was revealed. Safety profiles were consistent with previous reports. CONCLUSION: Trastuzumab combined with ramucirumab and paclitaxel showed appreciable efficacy with manageable safety profiles in patients with previously treated HER2-positive G/GEJ cancer.


Assuntos
Neoplasias Esofágicas , Neoplasias Gástricas , Humanos , Trastuzumab , Paclitaxel , Intervalo Livre de Doença , Receptor ErbB-2/metabolismo , Neoplasias Gástricas/tratamento farmacológico , Junção Esofagogástrica/metabolismo , Neoplasias Esofágicas/tratamento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Ramucirumab
11.
Front Endocrinol (Lausanne) ; 13: 1048818, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36818465

RESUMO

PTH 1-34 (teriparatide) is approved by FDA for the treatment of postmenopausal osteoporosis. Iron overload is a major contributing factor for bone loss induced by unloading. Whether iron metabolism is involved in the regulation of PTH 1-34 on unloading-induced osteoporosis has not yet been reported. Here, we found that PTH 1-34 attenuated bone loss in unloading mice. PTH 1-34 regulated the disturbance of iron metabolism in unloading mice by activating Nrf2 and further promoting hepcidin expression in the liver. In addition, the Nrf2 inhibitor selectively blocked hepcidin expression in the liver of unloading mice, which neutralized the inhibitory effect of PTH 1-34 on bone loss and the recovery of iron metabolism in unloading mice. Finally, we found that PTH 1-34 promoted the differentiation and inhibited apoptosis of osteoblasts by regulating iron metabolism and maintaining redox balance under unloading conditions. Our results suggested that PTH 1-34 promoted bone formation by regulating iron metabolism under unloading conditions.


Assuntos
Hepcidinas , Osteogênese , Camundongos , Animais , Hepcidinas/farmacologia , Fator 2 Relacionado a NF-E2 , Hormônio Paratireóideo/farmacologia , Ferro
12.
Nat Commun ; 13(1): 6002, 2022 10 12.
Artigo em Inglês | MEDLINE | ID: mdl-36224176

RESUMO

In this multi-center phase II trial, we evaluated the efficacy and safety of a quadruplet regimen (pembrolizumab, trastuzumab, and doublet chemotherapy) as first-line therapy for unresectable or metastatic human epidermal growth factor receptor 2 (HER2)-positive advanced gastric cancer (AGC) (NCT02901301). The primary endpoints were recommended phase 2 dose (RP2D) for phase Ib and objective response rate (ORR) for phase II. The secondary endpoints included progression-free survival (PFS), overall survival (OS), duration of response, time to response and safety. Without dose-limiting or unexpected toxicities, the starting dose in the phase Ib trial was selected as RP2D. In 43 patients, the primary endpoint was achieved: the objective response rate was 76.7% (95% confidence interval [CI]: 61.4-88.2), with complete and partial responses in 14% and 62.8% of patients, respectively. The median progression-free survival, overall survival, and duration of response were 8.6 months, 19.3 months, and 10.8 months, respectively. No patients discontinued pembrolizumab because of immune-related adverse events. Programmed death ligand-1 status was not related to survival. Post hoc analyses of pretreatment tumor specimens via targeted sequencing indicated that ERBB2 amplification, RTK/RAS pathway alterations, and high neoantigen load corrected by HLA-B were positively related to survival. The current quadruplet regimen shows durable efficacy and safety for patients with HER2-positive AGC.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica , Neoplasias Gástricas , Anticorpos Monoclonais Humanizados/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Humanos , Receptor ErbB-2/genética , Receptor ErbB-2/metabolismo , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/genética , Trastuzumab/uso terapêutico
13.
Eur J Pharmacol ; 906: 174219, 2021 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-34081904

RESUMO

Heme oxygenase-1 (HO-1) exerts a protective effect against cell damage and induces the activity of many enzymes involved in the treatment of many human diseases, including osteoporosis. The increasing prevalence of osteoporosis and the limitations of the current treatments available led to a continuous occurrence of bone loss and osteoporotic fractures, highlighting the need of a better understanding of the mechanism and function of HO-1. Many factors cause osteoporosis, including lack of estrogen, aging, and iron overload, and they either cause the increase in inflammatory factors or the increase in reactive oxygen species to break bone reconstruction balance. Therefore, regulating the production of inflammatory factors and reactive oxygen species may become a strategy for the treatment of osteoporosis. Solid evidence showed that the overexpression of HO-1 compensates high oxidation levels by increasing intracellular antioxidant levels and reduces inflammation by suppressing pro-inflammatory factors. Some extracts can target HO-1 and ameliorate osteoporosis. However, no systematic report is available on therapies targeting HO-1 to combat osteoporosis. Therefore, this review summarizes the biological characteristics of HO-1, and the relationship between inflammatory response and reactive oxygen species production regulated by HO-1 and osteoporosis. The understanding of the role of HO-1 in osteoporosis may provide ideas for a potential clinical treatment and new drugs targeting HO-1.


Assuntos
Conservadores da Densidade Óssea/farmacologia , Heme Oxigenase-1/antagonistas & inibidores , Osteoporose/tratamento farmacológico , Animais , Conservadores da Densidade Óssea/uso terapêutico , Modelos Animais de Doenças , Heme Oxigenase-1/genética , Heme Oxigenase-1/metabolismo , Humanos , Inflamação/tratamento farmacológico , Inflamação/imunologia , Inflamação/patologia , Proteínas de Membrana/antagonistas & inibidores , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Osteogênese/efeitos dos fármacos , Osteoporose/imunologia , Osteoporose/patologia , Oxirredução/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/imunologia , Espécies Reativas de Oxigênio/metabolismo
14.
Cell Signal ; 84: 110024, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33901579

RESUMO

Iron is an essential element for crucial biological function; whereas excess iron sedimentation impairs the main functions of tissues or organs. Cumulative researches have shown that the disturbances in iron metabolism, especially iron overload is closely concatenating with bone loss. Nevertheless, the specific process of iron overload-induced apoptosis in osteoblasts has not been thoroughly studied. In this study, our purpose is to elucidate the mechanism of osteoblast apoptosis induced by iron overload via the MC3T3-E1 cell line. Ferric ammonium citrate (FAC) was utilized to simulate iron overload conditions in vitro. These results showed that treatment with FAC dose-dependently induced the apoptosis of MC3T3-E1 cells at 48 h, dysfunction of iron metabolism, and increased intracellular reactive oxygen species (ROS) levels. Following, FAC does-dependently caused the calcium dyshomeostasis, decreased the calcium concentration in endoplasmic reticulum (ER), but increased the crosstalk between ER and mitochondria, and calcium concentration in the mitochondria. Moreover, FAC dose-dependently decreased mitochondrial membrane potential (MMP) and enhanced the expression of apoptosis related proteins (Bax, Cyto-C and C-caspase3). We furthermore revealed that FAC treatment activated the ER-mediated cell apoptosis via p-eIF2α/ATF4/CHOP pathway in MC3T3-E1 osteoblasts cells. In addition, pretreatment with the N-acetylcysteine (NAC) or Tauroursodeoxycholate Sodium (TUDC) attenuated cell apoptosis, ROS levels, mitochondria fragmentation and ER stress-related protein expression, and recovered the protein expression related to iron metabolism. In conclusion, our finding suggested that iron overload induced apoptosis via eliciting ER stress, which resulted in mitochondrial dysfunction and activated p-eIF2α/ATF4/CHOP pathway.


Assuntos
Fator de Iniciação 2 em Eucariotos , Sobrecarga de Ferro , Fator 4 Ativador da Transcrição/metabolismo , Animais , Apoptose , Estresse do Retículo Endoplasmático , Fator de Iniciação 1 em Eucariotos , Fator de Iniciação 2 em Eucariotos/metabolismo , Humanos , Sobrecarga de Ferro/metabolismo , Camundongos , Mitocôndrias/metabolismo , Osteoblastos/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Fator de Transcrição CHOP
15.
Biol Trace Elem Res ; 195(2): 353-365, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31473898

RESUMO

Iron is one of the important trace elements in life activities. Abnormal iron metabolism increases the incidence of many skeletal diseases, especially for osteoporosis. Iron metabolism plays a key role in the bone homeostasis. Disturbance of iron metabolism not only promotes osteoclast differentiation and apoptosis of osteoblasts but also inhibits proliferation and differentiation of osteoblasts, which eventually destroys the balance of bone remodeling. The strength and density of bone can be weakened by the disordered iron metabolism, which increases the incidence of osteoporosis. Clinically, compounds or drugs that regulate iron metabolism are used for the treatment of osteoporosis. The goal of this review summarizes the new progress on the effect of iron overload or deficiency on osteoporosis and the mechanism of disordered iron metabolism on osteoporosis. Explaining the relationship of iron metabolism with osteoporosis may provide ideas for clinical treatment and development of new drugs.


Assuntos
Sobrecarga de Ferro/metabolismo , Ferro/metabolismo , Osteoporose/metabolismo , Apoptose , Diferenciação Celular , Proliferação de Células , Humanos , Deficiências de Ferro , Osteoclastos/metabolismo , Osteoclastos/patologia
16.
Genomics Inform ; 18(4): e37, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33412753

RESUMO

BET inhibitor, as an epigenetic regulator inhibitor, reduces the expression of oncogenes such as Myc and Bcl-2, which affects cancer growth and development. However, it has modest activity because of the narrow therapeutic index. Therefore, combination therapy is necessary to increase the anti-tumor effect. Paclitaxel, an anti-mitotic inhibitor, is used as second-line therapy for gastric cancer (GC) as a monotherapy or combination. In this study, we performed RNA sequencing of GC cells treated with iBET-151 and/or paclitaxel to identify the differentially expressed genes associated with possible mechanisms of synergistic effect. We also performed Gene Ontology enrichment and Kyoto Encyclopedia of Genes and Genomes pathway analyses to determine the most enriched terms and pathways of upregulated and downregulated genes. We found 460 genes in which iBET-151 and paclitaxel combination treatment changed more than single-treatment or no-treatment. Thus, additional functional studies are needed, but our results provide the first evidence of the synergistic effect between iBET-151 and paclitaxel in regulating the transcriptome of GC cells.

17.
Oxid Med Cell Longev ; 2019: 9290728, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31827709

RESUMO

Osteosarcoma is the most frequently diagnosed primary malignant bone sarcoma in children and adolescents. Recent studies have shown that cancer stem cells (CSCs), a cluster of tumor cells with the ability to self-renew, play an essential role in tumor recurrence and metastasis. Thus, it is necessary to develop therapeutic strategies specifically targeting CSCs. Metformin, the first-line drug for type 2 diabetes, exhibits antineoplastic activities in various kinds of tumors. New evidence has suggested that metformin may target CSCs and prevent their recurrence. However, the underlying specific mechanisms remain unclear. In this study, we found that metformin significantly suppressed the self-renewal ability of osteosarcoma stem cells (OSCs) and induced G0/G1 phase arrest by blocking the activity of cyclin-dependent kinases. Furthermore, metformin induced apoptosis through a mitochondria-dependent pathway, leading to the collapse of the mitochondrial transmembrane potential and the production of reactive oxygen species (ROS). Importantly, metformin acted directly on the mitochondria, which resulted in decreased ATP synthesis. This change allowed access to the downstream AMPK kinase, and the activation of AMPK led to the reversal of the mTOR pathway, triggering autophagy. Particularly, metformin-mediated autophagy disturbed the homeostasis of stemness and pluripotency in the OSCs. Additionally, our mouse xenograft model confirmed the potential therapeutic use of metformin in targeting OSCs. In conclusion, our findings suggest that metformin suppresses the self-renewal ability and tumorigenicity of OSCs via ROS-mediated apoptosis and autophagy.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Autofagia , Autorrenovação Celular/efeitos dos fármacos , Metformina/farmacologia , Osteossarcoma/tratamento farmacológico , Espécies Reativas de Oxigênio/metabolismo , Animais , Neoplasias Ósseas/tratamento farmacológico , Neoplasias Ósseas/metabolismo , Neoplasias Ósseas/patologia , Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Humanos , Hipoglicemiantes/farmacologia , Masculino , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Osteossarcoma/metabolismo , Osteossarcoma/patologia , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
18.
Biomed Res Int ; 2015: 576349, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25874220

RESUMO

In order to understand disease pathogenesis, improve medical diagnosis, or discover effective drug targets, it is important to identify significant genes deeply involved in human disease. For this purpose, many earlier approaches attempted to prioritize candidate genes using gene expression profiles or SNP genotype data, but they often suffer from producing many false-positive results. To address this issue, in this paper, we propose a meta-analysis strategy for gene prioritization that employs three different genetic resources--gene expression data, single nucleotide polymorphism (SNP) genotype data, and expression quantitative trait loci (eQTL) data--in an integrative manner. For integration, we utilized an improved technique for the order of preference by similarity to ideal solution (TOPSIS) to combine scores from distinct resources. This method was evaluated on two publicly available datasets regarding prostate cancer and lung cancer to identify disease-related genes. Consequently, our proposed strategy for gene prioritization showed its superiority to conventional methods in discovering significant disease-related genes with several types of genetic resources, while making good use of potential complementarities among available resources.


Assuntos
Regulação da Expressão Gênica , Doenças Genéticas Inatas/genética , Modelos Genéticos , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas , Doenças Genéticas Inatas/diagnóstico , Humanos
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