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1.
Cancer Immunol Immunother ; 72(12): 4457-4470, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37796299

RESUMO

BACKGROUND: The inducible Kras/p53 lung adenocarcinoma mouse model, which faithfully recapitulates human disease, is routinely initiated by the intratracheal instillation of a virus-based Cre recombinase delivery system. Handling virus-based delivery systems requires elevated biosafety levels, e.g., biosafety level 2 (BSL-2). However, in experimental animal research facilities, following exposure to viral vectors in a BSL-2 environment, rodents may not be reclassified to BSL-1 according to standard practice, preventing access to small animal micro-computed tomography (micro-CT) scanners that are typically housed in general access areas such as BSL-1 rooms. Therefore, our goal was to adapt the protocol so that the Cre-induced KP mouse model could be handled under BSL-1 conditions during the entire procedure. RESULTS: The Kras-Lox-STOP-Lox-G12D/p53 flox/flox (KP)-based lung adenocarcinoma mouse model was activated by intratracheal instillation of either an adenoviral-based or a gutless, adeno-associated viral-based Cre delivery system. Tumor growth was monitored over time by micro-CT. We have successfully substituted the virus-based Cre delivery system with a commercially available, gutless, adeno-associated, Cre-expressing vector that allows the KP mouse model to be handled and imaged in a BSL-1 facility. By optimizing the anesthesia protocol and switching to a microscope-guided vector instillation procedure, productivity was increased and procedure-related complications were significantly reduced. In addition, repeated micro-CT analysis of individual animals allowed us to monitor tumor growth longitudinally, dramatically reducing the number of animals required per experiment. Finally, we documented the evolution of tumor volume for different doses, which revealed that individual tumor nodules induced by low-titer AAV-Cre transductions can be monitored over time by micro-CT. CONCLUSION: Modifications to the anesthesia and instillation protocols increased the productivity of the original KP protocol. In addition, the switch to a gutless, adeno-associated, Cre-expressing vector allowed longitudinal monitoring of tumor growth under BSL-1 conditions, significantly reducing the number of animals required for an experiment, in line with the 3R principles.


Assuntos
Adenocarcinoma de Pulmão , Neoplasias Pulmonares , Camundongos , Animais , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Proteínas Proto-Oncogênicas p21(ras)/genética , Dependovirus/genética , Microtomografia por Raio-X , Proteína Supressora de Tumor p53 , Contenção de Riscos Biológicos , Modelos Animais de Doenças , Vetores Genéticos/genética
2.
Cell Mol Life Sci ; 79(8): 445, 2022 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-35877003

RESUMO

Once considered a waste product of anaerobic cellular metabolism, lactate has been identified as a critical regulator of tumorigenesis, maintenance, and progression. The putative primary function of lactate dehydrogenase B (LDHB) is to catalyze the conversion of lactate to pyruvate; however, its role in regulating metabolism during tumorigenesis is largely unknown. To determine whether LDHB plays a pivotal role in tumorigenesis, we performed 2D and 3D in vitro experiments, utilized a conventional xenograft tumor model, and developed a novel genetically engineered mouse model (GEMM) of non-small cell lung cancer (NSCLC), in which we combined an LDHB deletion allele with an inducible model of lung adenocarcinoma driven by the concomitant loss of p53 (also known as Trp53) and expression of oncogenic KRAS (G12D) (KP). Here, we show that epithelial-like, tumor-initiating NSCLC cells feature oxidative phosphorylation (OXPHOS) phenotype that is regulated by LDHB-mediated lactate metabolism. We show that silencing of LDHB induces persistent mitochondrial DNA damage, decreases mitochondrial respiratory complex activity and OXPHOS, resulting in reduced levels of mitochondria-dependent metabolites, e.g., TCA intermediates, amino acids, and nucleotides. Inhibition of LDHB dramatically reduced the survival of tumor-initiating cells and sphere formation in vitro, which can be partially restored by nucleotide supplementation. In addition, LDHB silencing reduced tumor initiation and growth of xenograft tumors. Furthermore, we report for the first time that homozygous deletion of LDHB significantly reduced lung tumorigenesis upon the concomitant loss of Tp53 and expression of oncogenic KRAS without considerably affecting the animal's health status, thereby identifying LDHB as a potential target for NSCLC therapy. In conclusion, our study shows for the first time that LDHB is essential for the maintenance of mitochondrial metabolism, especially nucleotide metabolism, demonstrating that LDHB is crucial for the survival and proliferation of NSCLC tumor-initiating cells and tumorigenesis.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Animais , Carcinogênese/genética , Carcinogênese/metabolismo , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , DNA Mitocondrial/genética , DNA Mitocondrial/metabolismo , Homozigoto , Humanos , Isoenzimas , L-Lactato Desidrogenase/genética , L-Lactato Desidrogenase/metabolismo , Lactatos/metabolismo , Neoplasias Pulmonares/patologia , Camundongos , Mitocôndrias/metabolismo , Células-Tronco Neoplásicas/metabolismo , Nucleotídeos/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/genética , Deleção de Sequência
3.
Molecules ; 28(10)2023 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-37241757

RESUMO

Plant-based protein products, represented by "plant meat", are gaining more and more popularity as an alternative to animal proteins. In the present review, we aimed to update the current status of research and industrial growth of plant-based protein products, including plant-based meat, plant-based eggs, plant-based dairy products, and plant-based protein emulsion foods. Moreover, the common processing technology of plant-based protein products and its principles, as well as the emerging strategies, are given equal importance. The knowledge gap between the use of plant proteins and animal proteins is also described, such as poor functional properties, insufficient texture, low protein biomass, allergens, and off-flavors, etc. Furthermore, the nutritional and health benefits of plant-based protein products are highlighted. Lately, researchers are committed to exploring novel plant protein resources and high-quality proteins with enhanced properties through the latest scientific and technological interventions, including physical, chemical, enzyme, fermentation, germination, and protein interaction technology.


Assuntos
Laticínios , Carne , Animais , Ovos
4.
Environ Monit Assess ; 195(8): 970, 2023 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-37466699

RESUMO

River sediment is vital in containing water pollution and strengthening water remediation. This paper has conducted a study on the microecological health assessment of the sediment and water body of Guixi River in Dianjiang, Chongqing, China, using metagenomics sequencing and microbial biological integrity index (M-IBI) technology. The analysis of physical and chemical characteristics shows that the concentration of TN varies from 2.62 to 9.76 mg/L in each sampling section, and the eutrophication of the water body is relatively severe. The proportion of Cyanobacteria in the sampling section at the sink entrance is higher than that of other sites, where there are outbreaks of water blooms and potential hazards to human health. The dominant functions of each site include carbon metabolism, TCA cycle, and pyruvate metabolism. In addition, the main virulence factors and antibiotic resistance genes in sediment are Type IV pili (VF0082), LOS (CVF494), MymA operon (CVF649), and macrolide resistance genes macB, tetracyclic tetA (58), and novA. Correlation analysis of environmental factors and microorganisms was also performed, and it was discovered that Thiothrix and Acidovorax had obvious gene expression in the nitrogen metabolism pathway, and the Guixi River Basin had a self-purification capacity. Finally, based on the microecological composition of sediment and physical and chemical characteristics of the water body, the health assessment was carried out, indicating that the main pollution area was Dianjiang Middle School and the watershed near the sewage treatment plant. The findings should theoretically support an in-depth assessment of the water environment's microecological health.


Assuntos
Monitoramento Ambiental , Metagenômica , Rios , Poluentes Químicos da Água , China , Poluentes Químicos da Água/análise , Farmacorresistência Bacteriana , Genes Bacterianos , Humanos
5.
Biochem Biophys Res Commun ; 608: 177-182, 2022 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-35427895

RESUMO

C-di-GMP is a ubiquitous second messenger in bacterium, which regulates cellular functions such as the formation of biofilm membrane, cell mobility, virulence, cell adhesion, cell cycle et al. These functions are associated with an increasing number of c-di-GMP effector proteins and/or riboswitchs. In the study, CEP1 (c-di-GMP effector protein 1), a novel c-di-GMP binding protein, was screened with a combination of affinity pull-down and LC/MS/MS methods. The binding of CEP1 and c-di-GMP was demonstrated by surface plasmon resonance, with the dissociation constants of 127 ± 1.03 µM. Quantitative real time PCR assay showed the mRNA levels of cep1 gene in Rhodococcus ruber SD3 increased to 63.29 times and 71.18 times after toluene and phenol stress, respectively. Furthermore, cep1 gene enhanced strain was constructed using shuttle plasmid pNV18, which showed improved growth compared to the wild-type strain in the presence of different organic solvents. The study provided an insight into a mechanism, by which c-di-GMP was connected with organic solvent tolerance of Rhodococcus ruber SD3.


Assuntos
Rhodococcus , Espectrometria de Massas em Tandem , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Biofilmes , GMP Cíclico/análogos & derivados , GMP Cíclico/metabolismo , Regulação Bacteriana da Expressão Gênica , Rhodococcus/genética , Rhodococcus/metabolismo
6.
Small ; 18(19): e2107540, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35322548

RESUMO

Polar domain walls in centrosymmetric ferroelastics induce inhomogeneity that is the origin of advantageous multifunctionality. In particular, polar domain walls promote charge-carrier separation and hence are promising for energy conversion applications that overcome the hurdles of the rate-limiting step in the traditional photoelectrochemical water splitting processes. Yet, while macroscopic studies investigate the materials at the device scale, the origin of this phenomenon in general and the emergence of polar domain walls during the structural phase transition in particular has remained elusive, encumbering the development of this attractive system. Here, it is demonstrated that twin domain walls arise in centrosymmetric BiVO4 films and they exhibit localized piezoelectricity. It is also shown that during the structural phase transition from the tetragonal to monoclinic, the symmetry reduction is accompanied by an emergence of strain gradient, giving rise to flexoelectric effect and the polar domain walls. These results not only expose the emergence of polar domain walls at centrosymmetric systems by means of direct observation, but they also expand the realm of potential application of ferroelastics, especially in photoelectrochemistry and local piezoelectricity.

7.
Int J Mol Sci ; 23(19)2022 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-36233258

RESUMO

Malignant pleural mesothelioma (MPM) is a rare but aggressive thoracic malignancy with limited treatment options. One of the standard treatments for MPM is chemotherapy, which consists of concurrent treatment with pemetrexed and cisplatin. Pemetrexed limits tumor growth by inhibiting critical metabolic enzymes involved in nucleotide synthesis. Cisplatin causes direct DNA damage, such as intra-strand and inter-strand cross-links, which are repaired by the nucleotide excision repair pathway, which depends on relatively high nucleotide levels. We hypothesized that prolonged pretreatment with pemetrexed might deplete nucleotide pools, thereby sensitizing cancer cells to subsequent cisplatin treatment. The MPM cell lines ACC-MESO-1 and NCI-H28 were treated for 72 h with pemetrexed. Three treatment schedules were evaluated by initiating 24 h of cisplatin treatment at 0 h (concomitant), 24 h, and 48 h relative to pemetrexed treatment, resulting in either concomitant administration or pemetrexed pretreatment for 24 h or 48 h, respectively. Multicolor flow cytometry was performed to detect γH2AX (phosphorylation of histone H2AX), a surrogate marker for the activation of the DNA damage response pathway. DAPI staining of DNA was used to analyze cell cycle distribution. Forward and side scatter intensity was used to distinguish subpopulations based on cellular size and granularity, respectively. Our study revealed that prolonged pemetrexed pretreatment for 48 h prior to cisplatin significantly reduced long-term cell growth. Specifically, pretreatment for 48 h with pemetrexed induced a cell cycle arrest, mainly in the G2/M phase, accumulation of persistent DNA damage, and induction of a senescence phenotype. The present study demonstrates that optimizing the treatment schedule by pretreatment with pemetrexed increases the efficacy of the pemetrexed-cisplatin combination therapy in MPM. We show that the observed benefits are associated with the persistence of treatment-induced DNA damage. Our study suggests that an adjustment of the treatment schedule could improve the efficacy of the standard chemotherapy regimen for MPM and might improve patient outcomes.


Assuntos
Neoplasias Pulmonares , Mesotelioma Maligno , Mesotelioma , Neoplasias Pleurais , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Cisplatino/farmacologia , Cisplatino/uso terapêutico , Histonas , Humanos , Neoplasias Pulmonares/patologia , Mesotelioma/tratamento farmacológico , Mesotelioma/patologia , Nucleotídeos , Pemetrexede/farmacologia , Pemetrexede/uso terapêutico , Neoplasias Pleurais/tratamento farmacológico , Neoplasias Pleurais/patologia
8.
Korean J Parasitol ; 59(6): 635-638, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34974670

RESUMO

In this study, we intended to describe a human case of lumbosacral canal sparganosis in People's Republic of China (China). A 56-year-old man was admitted to Xiangya Hospital Central South University in Changsha, Hunan province, China after having an experience of perianal pain for a week. An enhancing mass, a tumor clinically suggested, was showed at the S1-S2 level of the lumbosacral spine by the examination of magnetic resonance imaging (MRI) with gadolinium contrast. The patient was received the laminectomy from S1 to S2, and an ivory-white living worm was detected in inferior margin of L5. In ELISA-test with cerebrospinal fluid (CSF) and serum samples, anti-sparganum antibodies were detected. He had a ingesting history of undercooked frog meat in his youth. By the present study, a human case of spinal sparganosis invaded in lumbosacral canal at the S1-S2 level was diagnosed in China. Although the surgical removal of larvae is known to be the best way of treatment for sparganosis, we administered the high-dosage of praziquantel, albendazole and dexamethasone to prevent the occurrence of another remain worms in this study.


Assuntos
Esparganose , Adolescente , Animais , China , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Praziquantel , Esparganose/diagnóstico por imagem , Esparganose/cirurgia , Plerocercoide
9.
J Cell Physiol ; 235(1): 74-86, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31222740

RESUMO

Multiple modalities for lung cancer therapy have emerged in the past decade, whereas their clinical applications and survival-beneficiary is little known. Vaccination with dendritic cells (DCs) or DCs/cytokine-induced killer (CIK) cells has shown limited success in the treatment of patients with advanced non-small-cell lung cancer. To evaluate and overcome these limitations in further studies, in the present review, we sum up recent progress about DCs or DCs/CIKs-based approaches for preclinical and clinical trials in patients with lung cancer and discuss some of the limited therapeutic success. Moreover, this review highlights the need to focus future studies on the development of new approaches for successful immunotherapy in patients with lung cancer.


Assuntos
Células Matadoras Induzidas por Citocinas , Células Dendríticas , Fatores Imunológicos/uso terapêutico , Imunoterapia/métodos , Neoplasias Pulmonares/terapia , Humanos
10.
Am J Physiol Lung Cell Mol Physiol ; 319(5): L794-L809, 2020 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-32726135

RESUMO

Lung injury in mice induces mobilization of discrete subsets of epithelial progenitor cells to promote new airway and alveolar structures. However, whether similar cell types exist in human lung remains unresolved. Using flow cytometry, we identified a distinct cluster of cells expressing the epithelial cell adhesion molecule (EpCAM), a cell surface marker expressed on epithelial progenitor cells, enriched in the ecto-5'-nucleotidase CD73 in unaffected postnatal human lungs resected from pediatric patients with congenital lung lesions. Within the EpCAM+CD73+ population, a small subset coexpresses integrin ß4 and HTII-280. This population remained stable with age. Spatially, EpCAM+CD73+ cells were positioned along the basal membrane of respiratory epithelium and alveolus next to CD73+ cells lacking EpCAM. Expanded EpCAM+CD73+ cells give rise to a pseudostratified epithelium in a two-dimensional air-liquid interface or a clonal three-dimensional organoid assay. Organoids generated under alveolar differentiation conditions were cystic-like and lacked robust alveolar mature cell types. Compared with unaffected postnatal lung, congenital lung lesions were marked by clusters of EpCAM+CD73+ cells in airway and cystic distal lung structures lined by simple epithelium composed of EpCAM+SCGB1A1+ cells and hyperplastic EpCAM+proSPC+ cells. In non-small-cell lung cancer (NSCLC), there was a marked increase in EpCAM+CD73+ tumor cells enriched in inhibitory immune checkpoint molecules CD47 and programmed death-ligand 1 (PD-L1), which was associated with poor survival in lung adenocarcinoma (LUAD). In conclusion, EpCAM+CD73+ cells are rare novel epithelial progenitor cells in the human lung. Importantly, reemergence of CD73 in lung adenocarcinoma enriched in negative immune checkpoint molecules may serve as a novel therapeutic target.


Assuntos
5'-Nucleotidase/metabolismo , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Células Epiteliais/metabolismo , Células-Tronco/citologia , Animais , Diferenciação Celular/fisiologia , Molécula de Adesão da Célula Epitelial/metabolismo , Humanos , Pulmão/patologia , Neoplasias Pulmonares/metabolismo , Células-Tronco Mesenquimais/metabolismo , Camundongos
11.
Am J Physiol Lung Cell Mol Physiol ; 318(4): L813-L830, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-32073879

RESUMO

Our understanding of mesenchymal cell subsets and their function in human lung affected by aging and in certain disease settings remains poorly described. We use a combination of flow cytometry, prospective cell-sorting strategies, confocal imaging, and modeling of microvessel formation using advanced microfluidic chip technology to characterize mesenchymal cell subtypes in human postnatal and adult lung. Tissue was obtained from patients undergoing elective surgery for congenital pulmonary airway malformations (CPAM) and other airway abnormalities including chronic obstructive pulmonary disease (COPD). In microscopically normal postnatal human lung, there was a fivefold higher mesenchymal compared with epithelial (EpCAM+) fraction, which diminished with age. The mesenchymal fraction composed of CD90+ and CD90+CD73+ cells was enriched in CXCL12 and platelet-derived growth factor receptor-α (PDGFRα) and located in close proximity to EpCAM+ cells in the alveolar region. Surprisingly, alveolar organoids generated from EpCAM+ cells supported by CD90+ subset were immature and displayed dysplastic features. In congenital lung lesions, cystic air spaces and dysplastic alveolar regions were marked with an underlying thick interstitium composed of CD90+ and CD90+PDGFRα+ cells. In postnatal lung, a subset of CD90+ cells coexpresses the pericyte marker CD146 and supports self-assembly of perfusable microvessels. CD90+CD146+ cells from COPD patients fail to support microvessel formation due to fibrinolysis. Targeting the plasmin-plasminogen system during microvessel self-assembly prevented fibrin gel degradation, but microvessels were narrower and excessive contraction blocked perfusion. These data provide important new information regarding the immunophenotypic identity of key mesenchymal lineages and their change in a diverse setting of congenital lung lesions and COPD.


Assuntos
Imunomodulação/imunologia , Células-Tronco Mesenquimais/metabolismo , Antígenos Thy-1/imunologia , Antígenos Thy-1/metabolismo , Adolescente , Biomarcadores/metabolismo , Antígeno CD146/imunologia , Antígeno CD146/metabolismo , Separação Celular/métodos , Criança , Pré-Escolar , Molécula de Adesão da Célula Epitelial/imunologia , Molécula de Adesão da Célula Epitelial/metabolismo , Feminino , Humanos , Fatores Imunológicos/imunologia , Fatores Imunológicos/metabolismo , Lactente , Recém-Nascido , Masculino , Células-Tronco Mesenquimais/imunologia , Microvasos/imunologia , Microvasos/metabolismo , Pericitos/imunologia , Pericitos/metabolismo , Estudos Prospectivos
12.
BMC Plant Biol ; 19(1): 19, 2019 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-30634907

RESUMO

BACKGROUND: Verticillium wilt (VW), also known as "cotton cancer," is one of the most destructive diseases in global cotton production that seriously impacts fiber yield and quality. Despite numerous attempts, little significant progress has been made in improving the VW resistance of upland cotton. The development of chromosome segment substitution lines (CSSLs) from Gossypium hirsutum × G. barbadense has emerged as a means of simultaneously developing new cotton varieties with high-yield, superior fiber, and resistance to VW. RESULTS: In this study, VW-resistant investigations were first conducted in an artificial greenhouse, a natural field, and diseased nursery conditions, resulting in the identification of one stably VW-resistant CSSL, MBI8255, and one VW-susceptible G. hirsutum, CCRI36, which were subsequently subjected to biochemical tests and transcriptome sequencing during V991 infection (0, 1, and 2 days after inoculation). Eighteen root samples with three replications were collected to perform multiple comparisons of enzyme activity and biochemical substance contents. The findings indicated that VW resistance was positively correlated with peroxidase and polyphenol oxidase activity, but negatively correlated with malondialdehyde content. Additionally, RNA sequencing was used for the same root samples, resulting in a total of 77,412 genes, of which 23,180 differentially expressed genes were identified from multiple comparisons between samples. After Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis on the expression profiles identified using Short Time-series Expression Miner, we found that the metabolic process in the biological process, as well as the pathways of phenylpropanoid biosynthesis and plant hormone signal transduction, participated significantly in the response to VW. Gene functional annotation and expression quantity analysis indicated the important roles of the phenylpropanoid metabolic pathway and oxidation-reduction process in response to VW, which also provided plenty of candidate genes related to plant resistance. CONCLUSIONS: This study concentrates on the preliminary response to V991 infection by comparing the VW-resistant CSSL and its VW-susceptible recurrent parent. Not only do our findings facilitate the culturing of new resistant varieties with high yield and superior performance, but they also broaden our understanding of the mechanisms of cotton resistance to VW.


Assuntos
Cromossomos de Plantas/genética , Gossypium/genética , Gossypium/microbiologia , Transcriptoma/genética , Verticillium/patogenicidade , Regulação da Expressão Gênica de Plantas/genética
13.
Cancer Cell Int ; 19: 317, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31798346

RESUMO

BACKGROUND: Cisplatin plus pemetrexed combination therapy is considered the standard treatment for patients with advanced, non-squamous, non-small-cell lung cancer (NSCLC). However, advanced NSCLC has a 5-year survival rate of below 10%, which is mainly due to therapy resistance. We previously showed that the NSCLC cell line A549 harbors different subpopulations including a mesenchymal-like subpopulation characterized by increased chemo- and radiotherapy resistance. Recently, therapy resistance in hematological and solid tumors has been associated with increased mitochondrial activity. Thus, the aim of this study was to investigate the role of the mitochondrial activity in NSCLC chemotherapy resistance. METHODS: Based on MitoTracker staining, subpopulations characterized by the highest 10% (Mito-High) or lowest 10% (Mito-Low) mitochondrial mass content were sorted by FACS (Fluorescence-Activated Cell Sorting) from paraclonal cultures of the NSCLC A549 cell line . Mitochondrial DNA copy numbers were quantified by real-time PCR whereas basal cellular respiration was measured by high-resolution respirometry. Cisplatin and pemetrexed response were quantified by proliferation and colony formation assay. RESULTS: Pemetrexed treatment of parental A549 cells increased mitochondrial mass over time. FACS-sorted paraclonal Mito-High cells featured increased mitochondrial mass and mitochondrial DNA copy number compared to the Mito-Low cells. Paraclonal Mito-High cells featured an increased proliferation rate and were significantly more resistant to cisplatin treatment than Mito-Low cells. Interestingly, cisplatin-resistant, paraclonal Mito-High cells were significantly more sensitive to pemetrexed treatment than Mito-Low cells. We provide a working model explaining the molecular mechanism underlying the increased cisplatin- and decreased pemetrexed resistance of a distinct subpopulation characterized by high mitochondrial mass. CONCLUSIONS: This study revealed that cisplatin resistant A549 lung cancer cells can be identified by their increased levels of mitochondrial mass. However, Mito-High cells feature an increased sensitivity to pemetrexed treatment. Thus, pemetrexed and cisplatin target reciprocal lung cancer subpopulations, which could explain the increased efficacy of the combination therapy in the clinical setting.

14.
Protein Expr Purif ; 163: 105441, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31195084

RESUMO

Diguanylate cyclases (DGCs) were responsible for the synthesis of second messenger cyclic di-guanosine monophosphate (c-di-GMP), which were involved in various physiological activities of bacterial species. Here, a full-length DGC from Rhodococcus ruber SD3 fused with glutathione-S-transferase (GST) was expressed in E. coli and purified by glutathione agarose resin. The apparent molecular mass of one subunit of the purified diguanylate cyclase with GST tag (GST-DGC) was estimated to be 71.9 kDa by SDS-PAGE, which was approximately in accordance with the theoretical value of 73.0 kDa. The sequence of GST-DGC was confirmed by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). The blue native PAGE indicated that GST-DGC formed octamer. The optimum pH and temperature for GST-DGC activity were 8.0 and 47 °C, respectively. The fusion protein exhibited high thermostability, and 94% of activity was retained when the protein was incubated at 87 °C for 1 h. Moreover, the fusion protein showed pH stability. The Km, Vmax and Kcat values for GST-DGC enzyme were 9.8 µM, 0.7 µM/min and 1.3 S-1. Some ions such as Zn2+, Mn2+, Fe2+, Ni2+ and Co2+ had inhibitory effects on the activity of the protein, while other ions such as Mg2+, K+ and Na+ slightly activated the protein. The fusion protein also showed rather high stability in the presence of toluene, cyclohexane and n-hexane.


Assuntos
Proteínas de Escherichia coli/isolamento & purificação , Fósforo-Oxigênio Liases/isolamento & purificação , Rhodococcus/enzimologia , China , Cromatografia Líquida , Clonagem Molecular , DNA Bacteriano , Escherichia coli , Proteínas de Escherichia coli/metabolismo , Fósforo-Oxigênio Liases/metabolismo , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes de Fusão/genética , Rhodococcus/genética , Análise de Sequência de DNA , Microbiologia do Solo
15.
Br J Cancer ; 119(1): 65-75, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29921948

RESUMO

BACKGROUND: Standard treatment for advanced malignant pleural mesothelioma (MPM) is a cisplatin/pemetrexed (MTA) regimen; however, this is confronted by drug resistance. Proteotoxic stress in the endoplasmic reticulum (ER) is a hallmark of cancer and some rely on this stress signalling in response to cytotoxic chemotherapeutics. We hypothesise that ER stress and the adaptive unfolded protein response (UPR) play a role in chemotherapy resistance of MPM. METHODS: In vitro three-dimensional (3D) and ex vivo organotypic culture were used to enrich a chemotherapy-resistant population and recapitulate an in vivo MPM microenvironment, respectively. Markers of ER stress, the UPR and apoptosis were assessed at mRNA and protein levels. Cell viability was determined based on acid phosphatase activity. RESULTS: MPM cells with de novo and/or acquired chemotherapy resistance displayed low ER stress, which rendered the cells hypersensitive to agents that induce ER stress and alter the UPR. Bortezomib, an FDA-approved proteasome inhibitor, selectively impairs chemotherapy-resistant MPM cells by activating the PERK/eIF2α/ATF4-mediated UPR and augmenting apoptosis. CONCLUSIONS: We provide the first evidence for ER stress and the adaptive UPR signalling in chemotherapy resistance of MPM, which suggests that perturbation of the UPR by altering ER stress is a novel strategy to treat chemotherapy-refractory MPM.


Assuntos
Bortezomib/farmacologia , Neoplasias Pulmonares/tratamento farmacológico , Mesotelioma/tratamento farmacológico , Neoplasias Pleurais/tratamento farmacológico , Resposta a Proteínas não Dobradas/genética , Fator 4 Ativador da Transcrição/genética , Apoptose/genética , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos/genética , Retículo Endoplasmático , Estresse do Retículo Endoplasmático/genética , Fator de Iniciação 2 em Eucariotos/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Mesotelioma/genética , Mesotelioma/patologia , Mesotelioma Maligno , Neoplasias Pleurais/genética , Neoplasias Pleurais/patologia , Transdução de Sinais/efeitos dos fármacos , Resposta a Proteínas não Dobradas/efeitos dos fármacos , eIF-2 Quinase/genética
16.
Cell Physiol Biochem ; 42(2): 743-752, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28624824

RESUMO

AIM: The present study aimed to examine the effect of tumor necrosis factor-α (TNF-α) inhibition on bone marrow-derived mesenchymal stem cells (BMSCs) in neurological function recovery after spinal cord injury (SCI) via the Wnt signaling pathway in a rat model. METHODS: The rat model of SCI was established using Allen's method. Seventy-two adult male Sprague Dawley (SD) rats were randomly assigned into 4 groups (18 rats in each group): the sham control group, saline control group, BMSCs group (injection with BMSCs at the injured site) and BMSCs + TNF-α group (injection with BMSCs under TNF-α treatment at the injured site). Immunochemistry was performed to characterize the culture media after TNF-α-induced differentiation. qRT-PCR and Western blotting analyses were performed to detect the mRNA and protein expression of ß-catenin, Wnt3a, GSK-3ß and Axin. The Basso Beattie Bresnahan (BBB) locomotor score, neurological deficit score (NDS), and balance beam test (BBT) score were used to assess neurological functional recovery of SCI rats. RESULTS: In the BMSC group, numerous spherical cell clusters grew in suspension, and the cells were nestin-, NF200- and GFAP-positive. Compared with the sham control and BMSC groups, the ß-catenin and Wnt3a mRNA and protein expression was increased, but the GSK-3ß and Axin mRNA and protein expression was decreased in the BMSCs + TNF-α group. The SCI rats in the BMSCs + TNF-α group exhibited lower BBB scores, and higher NDSs and BBT scores compared to the BMSCs group. CONCLUSION: Our study provides evidence that TNF-α inhibition may weaken the ability of BMSCs in neurological functional recovery after SCI by activating the Wnt signaling pathway.


Assuntos
Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/metabolismo , Traumatismos da Medula Espinal/terapia , Fator de Necrose Tumoral alfa/genética , Animais , Medula Óssea/metabolismo , Diferenciação Celular/genética , Humanos , Ratos , Recuperação de Função Fisiológica/genética , Traumatismos da Medula Espinal/genética , Traumatismos da Medula Espinal/patologia , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Via de Sinalização Wnt/genética , beta Catenina/genética
17.
Cancer Cell Int ; 16(1): 66, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27594806

RESUMO

BACKGROUND: Lung cancer causes the most cancer deaths worldwide, thus there is a urgent need to develop new treatment options. Concurrent chemoradiotherapy has become a common strategy for the treatment of non-resectable solid tumors including non-small cell lung cancer. Pemetrexed is a folic acid antagonist that inhibits the synthesis of precursor nucleotides, whereas ionizing radiation induces DNA damage, the repair of which is dependent on sufficiently high nucleotide levels. In the clinical setting, the pemetrexed-ionizing radiation combination therapy is administered concomitantly. We hypothesized that prolonged pretreatment with pemetrexed could be beneficial, as prior depletion of nucleotide pools could sensitize cancer cells to subsequent irradiation. METHODS: Non-small cell lung cancer A549 cells were treated with 1 µM pemetrexed for 72 h. In addition, cells were exposed to five gray ionizing radiation either 1, 48 or 71 h after the initiation of the pemetrexed treatment. Cell growth, senescence induction, cell cycle distribution and DNA damage marker accumulation were analysed at different time points during the treatment and the recovery phase. RESULTS: Stand-alone treatments of five gray ionizing radiation and 1 µM pemetrexed resulted in an intermediate cell growth inhibition of A549 cells and were therefore applied as the combination regimen. Prolonged pemetrexed pretreatment for 71 h resulted in a significant S-phase accumulation. Irradiation and prolonged pemetrexed pretreatment maximally delayed long term cell growth. Additionally, senescence was augmented and recovery from treatment-induced DNA damage was most prominently delayed by prolonged pemetrexed pretreatment. CONCLUSIONS: Pretreatment with pemetrexed increases anticancer efficiency of pemetrexed-ionizing radiation combination therapy, which correlates with a persistence of treatment-induced DNA damage. Therefore, this study warrants further investigations to elucidate whether a similar adaptation to the standard treatment regimen could enhance the effectiveness of the non-small cell lung cancer clinical treatment regimen.

18.
BMC Cancer ; 16: 125, 2016 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-26895954

RESUMO

BACKGROUND: Lung cancer is the leading cause of cancer-related mortality, and new therapeutic options are urgently needed. Non-small cell lung cancer (NSCLC) accounts for approximately 85% of all lung cancers, with the current standard regimen of care for NSCLC including chemotherapy with pemetrexed as a single agent or in combination with platinum-based agents, e.g. cisplatin. Pemetrexed is a folic acid antagonist that inhibits the synthesis of precursor nucleotides, whereas cisplatin directly induces DNA adducts, the repair of which is dependent on sufficiently high nucleotide levels. In the clinical setting, the pemetrexed-cisplatin combination therapy is administered concomitantly. We hypothesized that prolonged pretreatment with pemetrexed could be beneficial, as prior depletion of nucleotide pools could sensitize cancer cells to subsequent treatment with cisplatin. METHODS: NSCLC A549 and H460 cells were treated with pemetrexed for 72 h. In addition, 24 h of cisplatin treatment was initiated at day 1, 2 or 3 resulting in either simultaneous pemetrexed application or pemetrexed pretreatment for 24 or 48 h, respectively. Cell growth and colony formation as well as senescence induction were quantified after treatment. Cell cycle distribution and phosphorylation of histone variant H2AX as a surrogate marker for DNA damage was quantified by flow cytometry. Relative changes in gene expression were determined by quantitative real time PCR. RESULTS: Prolonged pemetrexed pretreatment for 48 h prior to cisplatin treatment maximally delayed long-term cell growth and significantly reduced the number of recovering clones. Moreover, apoptosis and senescence were augmented and recovery from treatment-induced DNA damage was delayed. Interestingly, a cell population was identified that displayed an epithelial-to-mesenchymal transition (EMT) and which had a stem cell phenotype. This population was highly resistant to concomitant pemetrexed-cisplatin treatment but was sensitized by pemetrexed pretreatment. CONCLUSIONS: Adaptation of the standard treatment schedule to include pretreatment with pemetrexed optimizes the anticancer efficiency of pemetrexed-cisplatin combination therapy, which correlates with a persistence of treatment-induced DNA damage. Therefore, this study warrants further investigations to elucidate whether such an adaptation could enhance the effectiveness of the standard clinical treatment regimen. In addition, a subpopulation of therapy resistant cells with EMT and cancer stem cell features was identified that was resistant to the standard treatment regimen but sensitive to pemetrexed pretreatment combined with cisplatin.


Assuntos
Antineoplásicos/farmacologia , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Cisplatino/farmacologia , Dano ao DNA , Neoplasias Pulmonares/tratamento farmacológico , Pemetrexede/farmacologia , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Senescência Celular/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Sinergismo Farmacológico , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Células-Tronco Neoplásicas/efeitos dos fármacos
19.
Inorg Chem ; 55(24): 12660-12668, 2016 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-27989169

RESUMO

A novel lanthanide-organic framework (Eu-HODA), consisting of 2,2',3,3'-oxidiphthalic acids as efficient sensitizing units, is assembled and characterized. Eu-HODA features rare chiral helical channels despite the achiral nature of H4ODA. It is found that this MOF shows a unique luminescent response to methanol, in contrast to n-propanol and ethanol. Eu-HODA reveals a turn-off luminescence switching initiated by acetone molecules with an EC50 of 0.03 vol %, which is below the occupational exposure limit of acetone stipulated by the American Conference of Governmental Industrial Hygienists. Furthermore, it also exhibits high sensitivity (Stern-Volmer constant KSV = 2.09 × 104 L/mol) and low detection limit (6.4 ppb) for Fe3+ ions in pure water because of the existence of uncoordinated carboxyl groups within open frameworks. Eu-HODA-based test paper provides a simple and reliable detection method for Fe3+ in practical applications.


Assuntos
Európio/química , Compostos Férricos/química , Metanol/análise , Compostos Orgânicos/química , Adsorção , Cristalografia por Raios X , Luminescência , Soluções , Espectrofotometria Ultravioleta , Água/química
20.
Cancers (Basel) ; 16(2)2024 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-38275900

RESUMO

Once considered "undruggable" due to the strong affinity of RAS proteins for GTP and the structural lack of a hydrophobic "pocket" for drug binding, the development of proprietary therapies for KRAS-mutant tumors has long been a challenging area of research. CRISPR technology, the most successful gene-editing tool to date, is increasingly being utilized in cancer research. Here, we provide a comprehensive review of the application of the CRISPR system in basic and translational research in KRAS-mutant cancer, summarizing recent advances in the mechanistic understanding of KRAS biology and the underlying principles of drug resistance, anti-tumor immunity, epigenetic regulatory networks, and synthetic lethality co-opted by mutant KRAS.

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