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1.
Biomed Pharmacother ; 165: 115040, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37364479

RESUMO

Colorectal cancer (CRC) is one of highly prevalent cancer. Immunotherapy with immune checkpoint inhibitors (ICIs) has dramatically changed the landscape of treatment for many advanced cancers, but CRC still exhibits suboptimal response to immunotherapy. The gut microbiota can affect both anti-tumor and pro-tumor immune responses, and further modulate the efficacy of cancer immunotherapy, particularly in the context of therapy with ICIs. Therefore, a deeper understanding of how the gut microbiota modulates immune responses is crucial to improve the outcomes of CRC patients receiving immunotherapy and to overcome resistance in nonresponders. The present review aims to describe the relationship between the gut microbiota, CRC, and antitumor immune responses, with a particular focus on key studies and recent findings on the effect of the gut microbiota on the antitumor immune activity. We also discuss the potential mechanisms by which the gut microbiota influences host antitumor immune responses as well as the prospective role of intestinal flora in CRC treatment. Furthermore, the therapeutic potential and limitations of different modulation strategies for the gut microbiota are also discussed. These insights may facilitate to better comprehend the interplay between the gut microbiota and the antitumor immune responses of CRC patients and provide new research pathways to enhance immunotherapy efficacy and expand the patient population that could be benefited by immunotherapy.


Assuntos
Neoplasias Colorretais , Microbioma Gastrointestinal , Humanos , Imunoterapia , Inibidores de Checkpoint Imunológico , Neoplasias Colorretais/terapia
2.
Ann Transl Med ; 9(20): 1563, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34790769

RESUMO

BACKGROUND: The precise pathogenesis of ankylosing spondylitis (AS) is still largely unknown at present. Our previous study found that toll-like receptor 4 (TLR4) downregulated and performed immunoregulatory dysfunction in mesenchymal stem cells from AS patients (AS-MSCs). The aim of this study was to explore the expression profiles of long non-coding RNAs (lncRNAs) and messenger RNAs (mRNAs) in TLR4-primed AS-MSCs, and to clarify the potential mechanisms. METHODS: The immunoregulatory effects of MSCs were determined after TLR4 activation. Next, the differentially-expressed (DE) lncRNAs and mRNAs between AS-MSCs and TLR4-primed AS-MSCs [stimulated by lipopolysaccharide (LPS)] were identified via high-throughput sequencing followed by quantitative real-time PCR (qRT-PCR) confirmation. Finally, bioinformatics analyses were performed to identify the critical biological functions, signaling pathways, and associated functional networks involved in the TLR4-primed immunoregulatory function of AS-MSCs. RESULTS: A total of 147 DE lncRNAs and 698 DE mRNAs were identified between TLR4-primed AS-MSCs and unstimulated AS-MSCs. Of these, 107 lncRNAs were upregulated and 40 were downregulated (fold change ≥2, P<0.05), while 504 mRNAs were upregulated and 194 were downregulated (fold change ≥2, P<0.05). Five lncRNAs and five mRNAs with the largest fold changes were respectively verified by qRT-PCR. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses demonstrated that the DE mRNAs and lncRNAs were highly associated with the inflammatory response, such as NOD-like receptor (NLR) signaling pathway, the TNF signaling pathway and the NF-κB signaling pathway. Cis-regulation prediction revealed eight novel lncRNAs, while trans-regulation prediction revealed 15 lncRNAs, respectively. Eight core pairs of lncRNA and target mRNA in the lncRNA-transcription factor (TF)-mRNA network were as follows: PACERR-PTGS2, LOC105378085-SOD2, LOC107986655-HIVEP2, MICB-DT-MICB, LOC105373925-SP140L, LOC107984251-IFIT5, LOC112268267-GBP2, and LOC101926887-IFIT3, respectively. CONCLUSIONS: TLR4 activation in AS can enhance the immunoregulatory ability of MSCs. Eight core pairs of lncRNA and target mRNA were observed in TLR4-primed AS-MSCs, which could contribute to understanding the potential mechanism of AS-MSC immunoregulatory dysfunction.

3.
Stem Cells Int ; 2020: 8829212, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33354217

RESUMO

Bone remodeling is a process delicately balanced between osteoclastic bone resorption and osteoblastic bone formation. Osteoclasts (OCs) are multinucleated giant cells formed through the fusion of monocytic precursors of the hematopoietic stem cells lineage. OCs are the exclusive cells responsible for the resorption and degradation of the mineralized bone matrix. Pantoprazole (PPZ), a proton pump inhibitor (PPI), is commonly prescribed to reduce excess gastric acid production for conditions such as gastroesophageal reflux disease and peptic ulcer disease. Studies have found contradictory effects of PPI therapy on bone metabolism due to the lack of understanding of the exact underlying mechanism. In this study, we found that PPZ inhibits receptor activator of nuclear factor-κB (NF-κB) ligand- (RANKL-) induced osteoclastogenesis from bone marrow monocytic/macrophage (BMMs) precursors and the bone-resorbing activity of mature OCs. Correspondingly, the expression of OC marker genes was also attenuated. At the molecular level, PPZ treatment was associated with reduced activation of the ERK MAPK signaling pathways crucial to OC differentiation. Additionally, the in vivo administration of PPZ protected mice against lipopolysaccharide- (LPS-) induced inflammatory calvarial bone erosion, as a result of the reduced number and activity of OCs on the calvarial bone surface. Although PPI use is associated with increased risk of osteoporosis and bone fractures, our study provides evidence for the direct inhibitory effect of PPZ on OC formation and bone resorption in vitro and in vivo, suggesting a potential therapeutic use of PPZ in the treatment of osteolytic disease with localized bone destruction.

4.
Mol Plant Pathol ; 21(12): 1573-1590, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32969159

RESUMO

Although bacterial small noncoding RNAs (sRNAs) are known to play a critical role in various cellular processes, including pathogenesis, the identity and action of such sRNAs are still poorly understood in many organisms. Here we have performed a genome-wide screen and functional analysis of the sRNAs in Xanthomonas campestris pv. campestris (Xcc), an important phytopathogen. The 50-500-nt RNA fragments isolated from the wild-type strain grown in a virulence gene-inducing condition were sequenced and a total of 612 sRNA candidates (SRCs) were identified. The majority (82%) of the SRCs were derived from mRNA, rather than specific sRNA genes. A representative panel of 121 SRCs were analysed by northern blotting; 117 SRCs were detected, supporting the contention that the overwhelming majority of the 612 SRCs identified are indeed sRNAs. Phenotypic analysis of strains overexpressing different candidates showed that a particular sRNA, RsmU, acts as a negative regulator of virulence, the hypersensitive response, and cell motility in Xcc. In vitro electrophoretic mobility shift assay and in vivo coimmunoprecipitation analyses indicated that RsmU interacted with the global posttranscriptional regulator RsmA, although sequence analysis displayed that RsmU is not a member of the sRNAs families known to antagonize RsmA. Northern blotting analyses demonstrated that RsmU has two isoforms that are processed from the 3'-untranslated region of the mRNA of XC1332 predicted to encode ComEA, a periplasmic protein required for DNA uptake in bacteria. This work uncovers an unexpected major sRNA biogenesis strategy in bacteria and a hidden layer of sRNA-mediated virulence regulation in Xcc.


Assuntos
Proteínas de Bactérias/genética , Genoma Bacteriano/genética , Pequeno RNA não Traduzido/genética , Xanthomonas campestris/genética , Folhas de Planta/microbiologia , Isoformas de RNA/genética , RNA Mensageiro/genética , Virulência/genética , Xanthomonas campestris/patogenicidade
5.
Nat Commun ; 11(1): 2794, 2020 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-32493973

RESUMO

All known riboswitches use their aptamer to senese one metabolite signal and their expression platform to regulate gene expression. Here, we characterize a SAM-I riboswitch (SAM-IXcc) from the Xanthomonas campestris that regulates methionine synthesis via the met operon. In vitro and in vivo experiments show that SAM-IXcc controls the met operon primarily at the translational level in response to cellular S-adenosylmethionine (SAM) levels. Biochemical and genetic data demonstrate that SAM-IXcc expression platform not only can repress gene expression in response to SAM binding to SAM-IXcc aptamer but also can sense and bind uncharged initiator Met tRNA, resulting in the sequestering of the anti-Shine-Dalgarno (SD) sequence and freeing the SD for translation initiation. These findings identify a SAM-I riboswitch with a dual functioning expression platform that regulates methionine synthesis through a previously unrecognized mechanism and discover a natural tRNA-sensing RNA element. This SAM-I riboswitch appears to be highly conserved in Xanthomonas species.


Assuntos
RNA de Transferência de Metionina/metabolismo , Riboswitch , S-Adenosilmetionina/metabolismo , Sequência de Bases , Loci Gênicos , Modelos Biológicos , Conformação de Ácido Nucleico , Óperon/genética , Biossíntese de Proteínas , RNA de Transferência de Metionina/química , RNA de Transferência de Metionina/genética
6.
Microbiology (Reading) ; 164(9): 1146-1155, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30024369

RESUMO

The synthesis of methionine is critical for most bacteria. It is known that cellular methionine has a feedback effect on the expression of met genes involved in de novo methionine biosynthesis. Previous studies revealed that Gram-negative bacteria control met gene expression at the transcriptional level by regulator proteins, while most Gram-positive bacteria regulate met genes at post-transcriptional level by RNA regulators (riboregulators) located in the 5'UTR of met genes. However, despite its importance, the methionine biosynthesis pathway in the Gram-negative Xanthomonas genus that includes many important plant pathogens is completely uncharacterized. Here, we address this issue using the crucifer black rot pathogen Xanthomonas campestris pv. campestris (Xcc), a model bacterium in microbe-plant interaction studies. The work identified an operon (met) involved in de novo methionine biosynthesis in Xcc. Disruption of the operon resulted in defective growth in methionine-limited media and in planta. Western blot analysis revealed that the expression of the operon is dependent on methionine levels. Further molecular analyses demonstrated that the 5'UTR, but not the promoter of the operon, is involved in feedback regulation on operon expression in response to methionine availability, providing an example of a Gram-negative bacterium utilizing a 5'UTR region to control the expression of the genes involved in methionine biosynthesis.


Assuntos
Regiões 5' não Traduzidas , Retroalimentação Fisiológica , Regulação Bacteriana da Expressão Gênica , Metionina/biossíntese , Xanthomonas campestris/metabolismo , Deleção de Genes , Perfilação da Expressão Gênica , Óperon , Xanthomonas campestris/genética , Xanthomonas campestris/crescimento & desenvolvimento
7.
Environ Microbiol Rep ; 10(5): 542-554, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29901272

RESUMO

The RNA chaperone, Hfq, is known to play extensive roles in bacterial growth and development. More recently, it has been shown to be required for virulence in many human and animal bacterial pathogens. Despite these studies little is known about the role Hfq plays in phytopathogenic bacteria. In this study, we show Hfq is required for full virulence of the crucifer black rot pathogen Xanthomonas campestris pv. campestris (Xcc). We demonstrate that an Xcc hfq deletion strain is highly attenuated for virulence in Chinese radish and shows a severe defect in the production of virulence factors including extracellular enzymes and extracellular polysaccharide. Furthermore, the Xcc strain lacking Hfq had significantly reduced cell motility and stress tolerance. These findings suggest that Hfq is a key regulator of important aspects of virulence and adaptation of Xcc. Taken together, our findings are suggestive of a regulatory network placing Hfq at the centre of virulence gene expression control in Xcc.


Assuntos
Fator Proteico 1 do Hospedeiro/metabolismo , Doenças das Plantas/microbiologia , Proteínas de Ligação a RNA/metabolismo , Xanthomonas campestris/fisiologia , Xanthomonas campestris/patogenicidade , Adaptação Fisiológica , Deleção de Genes , Regulação Bacteriana da Expressão Gênica , Fator Proteico 1 do Hospedeiro/genética , Óperon/genética , Folhas de Planta/microbiologia , RNA Bacteriano/genética , RNA Bacteriano/metabolismo , Proteínas de Ligação a RNA/genética , Raphanus/microbiologia , Transcrição Gênica , Virulência/genética , Fatores de Virulência/genética , Fatores de Virulência/metabolismo , Xanthomonas campestris/enzimologia
8.
Chinese Medical Journal ; (24): 389-394, 2018.
Artigo em Inglês | WPRIM (Pacífico Ocidental) | ID: wpr-342026

RESUMO

<p><b>Background</b>Cervical cancer shows a growing incidence and medical cost in recent years that has increased severe financial pressure on patients and medical insurance institutions. This study aimed to investigate the medical economic characteristics of cervical cancer patients with different payment modes within a Grade A tertiary hospital to provide evidence and suggestions for inpatient cost control and to verify the application of Gamma model in medical cost analysis.</p><p><b>Methods</b>The basic and cost information of cervical cancer cases within a Grade A tertiary hospital in the year 2011-2016 were collected. The Gamma model was adopted to analyze the differences in each cost item between medical insured patient and uninsured patients. Meanwhile, the marginal means of different cost items were calculated to estimate the influence of payment modes toward different medical cost items among cervical cancer patients in the study.</p><p><b>Results:</b>A total of 1321 inpatients with cervical cancer between the 2011 and 2016 were collected through the medical records system. Of the 1321 cases, 65.9% accounted for medical insured patients and 34.1% were uninsured patients. The total inpatient medical expenditure of insured patients was RMB 29,509.1 Yuan and uninsured patients was RMB 22,114.3 Yuan, respectively. Payment modes, therapeutic options as well as the recurrence and metastasis of tumor toward the inpatient medical expenditures between the two groups were statistically significant. To the specifics, drug costs accounted for 37.7% and 33.8% of the total, surgery costs accounted for 21.5% and 25.5%, treatment costs accounted for 18.7% and 16.4%, whereas the costs of imaging and laboratory examinations accounted for 16.4% and 15.2% for the insured patient and uninsured patients, respectively. As the effects of covariates were controlled, the total hospitalization costs, drug costs, treatment costs as well as imaging and laboratory examination costs showed statistical significance. The total hospitalization costs, drug costs, treatment costs as well as imaging and laboratory examination costs of insured patient were 1.33, 1.42, 1.52, and 1.44 times of uninsured patients.</p><p><b>Conclusions</b>The analysis of different payment modes toward the medical economic characteristics based on Gamma model is basically rational. Medical payment modes are having certain influence toward the hospitalization expenses of cervical cancer patients in an extent, as drug costs, treatment costs, and examination costs appear to be the main causes.</p>

9.
Chinese Medical Journal ; (24): 1327-1332, 2018.
Artigo em Inglês | WPRIM (Pacífico Ocidental) | ID: wpr-688123

RESUMO

<p><b>Background</b>The development and application of medical technologies reflect the medical quality and clinical capacity of a hospital. It is also an effective approach in upgrading medical service and core competitiveness among medical institutions. This study aimed to build a quantitative medical technology evaluation system through questionnaire survey within medical institutions to perform an assessment to medical technologies more objectively and accurately, and promote the management of medical quality technologies and ensure the medical safety of various operations among the hospitals.</p><p><b>Methods</b>A two-leveled quantitative medical technology evaluation system was built through a two-round questionnaire survey of chosen experts. The Delphi method was applied in identifying the structure of evaluation system and indicators. The judgment of the experts on the indicators was adopted in building the matrix so that the weight coefficient and maximum eigenvalue (λ max), consistency index (CI), and random consistency ratio (CR) could be obtained and collected. The results were verified through consistency tests, and the index weight coefficient of each indicator was conducted and calculated through analytical hierarchy process.</p><p><b>Results</b>Twenty-six experts of different medical fields were involved in the questionnaire survey, 25 of whom successfully responded to the two-round research. Altogether, 4 primary indicators (safety, effectiveness, innovativeness, and benefits), as well as 13 secondary indicators, were included in the evaluation system. The matrix is built to conduct the λ max, CI, and CR of each expert in the survey, and the index weight coefficients of primary indicators were 0.33, 0.28, 0.27, and 0.12, respectively, and the index weight coefficients of secondary indicators were conducted and calculated accordingly.</p><p><b>Conclusions</b>As the two-round questionnaire survey of experts and statistical analysis were performed and credibility of the results was verified through consistency evaluation test, the study established a quantitative medical technology evaluation system model and assessment indicators within medical institutions based on the Delphi method and analytical hierarchy process. Moreover, further verifications, adjustments, and optimizations of the system and indicators will be performed in follow-up studies.</p>


Assuntos
Tecnologia Biomédica , Métodos , Inquéritos e Questionários
10.
Chinese Medical Journal ; (24): 1529-1533, 2017.
Artigo em Inglês | WPRIM (Pacífico Ocidental) | ID: wpr-330584

RESUMO

<p><b>BACKGROUND</b>With the rising incidence as well as the medical expenditure among patients with unstable angina pectoris, the research aimed to investigate the inpatient medical expenditure through the combination of diagnosis-related groups (DRGs) among patients with unstable angina pectoris in a Grade A tertiary hospital to conduct the referential standards of medical costs for the diagnosis.</p><p><b>METHODS</b>Single-factor analysis and multiple linear stepwise regression method were used to investigate 3933 cases between 2014 and 2016 in Beijing Hospital (China) whose main diagnosis was defined as unstable angina pectoris to determine the main factors influencing the inpatient medical expenditure, and decision tree method was adopted to establish the model of DRGs grouping combinations.</p><p><b>RESULTS</b>The major influential factors of inpatient medical expenditure included age, operative method, therapeutic effects as well as comorbidity and complications (CCs) of the disease, and the 3933 cases were divided into ten DRGs by four factors: age, CCs, therapeutic effects, and the type of surgery with corresponding inpatient medical expenditure standards setup. Data of nonparametric test on medical costs among different groups were all significant (P < 0.001, by Kruskal-Wallis test), with R2 = 0.53 and coefficient of variation (CV) = 0.524.</p><p><b>CONCLUSIONS</b>The classification of DRGs by adopting the type of surgery as the main branch node to develop cost control standards in inpatient treatment of unstable angina pectoris is conducive in standardizing the diagnosis and treatment behaviors of the hospital and reducing economic burdens among patients.</p>

11.
Chinese Medical Journal ; (24): 2325-2330, 2016.
Artigo em Inglês | WPRIM (Pacífico Ocidental) | ID: wpr-307415

RESUMO

<p><b>BACKGROUND</b>The study was to explore the causes of high inpatient expenditure through analyzing the distribution characteristics as well as the influence factors of high inpatient expenditure cases during 3 years within a Grade-A tertiary hospital through various aspects and multiple angles, thus identifying the major influence factors for high medical expenditure to develop further research.</p><p><b>METHODS</b>We retrospectively studied 2041 inpatient cases which cost more than RMB 100,000 Yuan per case in a Grade-A tertiary hospital from 2013 to 2015. We analyzed the compositions of the medical cost to evaluate the major factors that cause the high inpatient expenditure. All the data and materials were collected from medical record system, and the statistical methods included t-test, variance of analysis, and multivariate linear regression.</p><p><b>RESULTS</b>The average cost of the 2,041 cases was RMB 152,173 Yuan for medicines and materials of medical costs, which respectively accounted for 33.03% and 32.32% of the total cost; and the average length of hospital stay was 28.39 days/person. Diseases of skeletal and muscular system, circulatory system, and tumor were the top three disease categories of high inpatient expenditure, which accounted for 39.00%, 33.46%, and 18.03%, respectively. Complications, criticality of the disease, gender of the patients, the occurrence of death, and the excessive length of hospital stay all had great impacts on average medical expenditure, while age, hospital infection, and surgery showed no significant impact on average medical cost.</p><p><b>CONCLUSIONS</b>The main factors for high inpatient expenditure included the inadequate use of high-value medicines and materials, lacking cost control measures within the hospital, the excessive length of hospital stay for inpatients, and the unnecessary treatment for the patients.</p>


Assuntos
Feminino , Humanos , Masculino , China , Gastos em Saúde , Hospitalização , Economia , Pacientes Internados , Tempo de Internação , Economia , Análise Multivariada , Estudos Retrospectivos
12.
Int J Mol Sci ; 14(3): 5806-16, 2013 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-23481641

RESUMO

Lung cancer is the most common cause of cancer-related death. Nonetheless, a decrease in overall incidence and mortality has been observed in the last 30 years due to prevention strategies and improvements in the use of chemotherapeutic agents. In recent studies, Simvastatin (SIM) has demonstrated anti-tumor activity, as well as potent chemopreventive action. As an inhibitor of 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMG-CoA), SIM has been shown to stimulate apoptotic cell death. In this study, an MTT assay revealed the cytotoxic activity of SIM against human large cell lung cancer (Non-small cell lung cancer; NSCLC) cells (NCI-H460); however, induced apoptosis was not observed in NCI-H460 cells. Protein expression levels of cell cycle regulating proteins Cdk4, Cyclin D1, p16 and p27 were markedly altered by SIM. Collectively, our results indicate that SIM inhibits cell proliferation and arrests NCI-H460 cell cycle progression via inhibition of cyclin-dependent kinases and cyclins and the enhancement of CDK inhibitors p16 and p27. Our findings suggest that, in addition to the known effects on hypercholesterolemia therapy, SIM may also provide antitumor activity in established NSCLC.

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