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2.
Oncol Lett ; 25(2): 77, 2023 Feb.
Article de Anglais | MEDLINE | ID: mdl-36742365

RÉSUMÉ

Pancreatic cancer (PC) is a stubborn malignancy with high lethality and a low 5-year overall survival (OS) rate. Collagen type VII α1 chain (COL7A1), a major component of the extracellular matrix, serves important roles in numerous physiological processes and various illnesses. COL7A1 protein acts as an anchoring fibril between the external epithelial cells and the underlying stroma, and mutation of COL7A1 could cause recessive dystrophic epidermolysis bullosa. Raw data for PC were acquired from The Cancer Genome Atlas and the Gene Expression Omnibus database, and raw data for the normal pancreas were obtained from the Genotype-Tissue Expression database. COL7A1 mRNA expression in PC tissues was compared with that in either paired (GSE15471 dataset) or unpaired (all other data) normal pancreas tissues. The association between COL7A1 mRNA expression and clinicopathological factors was assessed using logistic regression analysis. Cox analysis and Kaplan-Meier analysis were used to evaluate the role of COL7A1 mRNA expression in prognosis and nomograms were constructed. Gene Ontology analysis, Kyoto Encyclopedia of Genes and Genomes analysis, Gene Set Enrichment Analysis (GSEA) and single-sample GSEA (ssGSEA) were performed to evaluate the relevant functions of COL7A1 and correlation with immune cell infiltration. Furthermore, reverse transcription-quantitative PCR was used to assess the mRNA expression levels of COL7A1 in PC. The present study demonstrated that COL7A1 mRNA expression was higher in PC tissues compared with in normal pancreas tissues. The Kaplan-Meier survival analysis indicated that patients with PC with high COL7A1 mRNA expression had shorter overall survival (OS), disease-specific survival (DSS) and progression-free interval (PFI) times compared with patients with PC with low COL7A1 mRNA expression. Multivariate analysis demonstrated that COL7A1 mRNA expression was an independent risk factor for OS, DSS and PFI. Nomogram and calibration plots were constructed to predict the prognosis of patients with PC. GSEA demonstrated that high mRNA expression levels of COL7A1 were associated with multiple cancer-related pathways. ssGSEA analysis indicated that COL7A1 expression was positively associated with natural killer CD56bright cells and T helper (Th)2 cells, and negatively associated with Th17 cells and eosinophils. The results of the present study suggested that COL7A1 could be an independent biomarker and an influential moderator of immune infiltration in PC.

3.
Autophagy ; 19(2): 551-569, 2023 02.
Article de Anglais | MEDLINE | ID: mdl-35670302

RÉSUMÉ

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is closely related to various cellular aspects associated with autophagy. However, how SARS-CoV-2 mediates the subversion of the macroautophagy/autophagy pathway remains largely unclear. In this study, we demonstrate that overexpression of the SARS-CoV-2 ORF7a protein activates LC3-II and leads to the accumulation of autophagosomes in multiple cell lines, while knockdown of the viral ORF7a gene via shRNAs targeting ORF7a sgRNA during SARS-CoV-2 infection decreased autophagy levels. Mechanistically, the ORF7a protein initiates autophagy via the AKT-MTOR-ULK1-mediated pathway, but ORF7a limits the progression of autophagic flux by activating CASP3 (caspase 3) to cleave the SNAP29 protein at aspartic acid residue 30 (D30), ultimately impairing complete autophagy. Importantly, SARS-CoV-2 infection-induced accumulated autophagosomes promote progeny virus production, whereby ORF7a downregulates SNAP29, ultimately resulting in failure of autophagosome fusion with lysosomes to promote viral replication. Taken together, our study reveals a mechanism by which SARS-CoV-2 utilizes the autophagic machinery to facilitate its own propagation via ORF7a.Abbreviations: 3-MA: 3-methyladenine; ACE2: angiotensin converting enzyme 2; ACTB/ß-actin: actin beta; ATG7: autophagy related 7; Baf A1: bafilomycin A1; BECN1: beclin 1; CASP3: caspase 3; COVID-19: coronavirus disease 2019; GFP: green fluorescent protein; hpi: hour post-infection; hpt: hour post-transfection; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MERS: Middle East respiratory syndrome; MTOR: mechanistic target of rapamycin kinase; ORF: open reading frame; PARP: poly(ADP-ribose) polymerase; SARS-CoV-2: severe acute respiratory syndrome coronavirus 2; shRNAs: short hairpin RNAs; siRNA: small interfering RNA; SNAP29: synaptosome associated protein 29; SQSTM1/p62: sequestosome 1; STX17: syntaxin 17; TCID50: tissue culture infectious dose; TEM: transmission electron microscopy; TUBB, tubulin, beta; ULK1: unc-51 like autophagy activating kinase 1.


Sujet(s)
Autophagie , COVID-19 , Humains , Autophagosomes/métabolisme , Autophagie/génétique , Caspase-3/métabolisme , Lysosomes/métabolisme , Macroautophagie , Protéines Qb-SNARE/métabolisme , Protéines Qc-SNARE , SARS-CoV-2 , Sérine-thréonine kinases TOR/métabolisme , Réplication virale
4.
Article de Anglais | MEDLINE | ID: mdl-35682009

RÉSUMÉ

Phase angle (PhA), a bioimpedance parameter, is used to assess the nutrition status and body composition of patients. Patients with pancreatic head cancer often present with body composition changes that relate to adverse outcomes. PhA may be useful to evaluate prognosis in these patients, but data are deficient. We aim to explore the effects of PhA on nutrition evaluation and short-term outcome prediction in these patients. This prospective study included 49 participants with pancreatic head cancer who underwent pancreaticoduodenectomy (PD). All participants' nutritional status and postoperative complications were assessed using nutrition assessment tools and the Clavien−Dindo classification method, respectively. Spearman correlation analyses were used to evaluate the association between PhA, nutrition status, and postoperative complications. ROC curves were generated to evaluate the ability of PhA to predict malnutrition and complications and to determine the cutoff value. The PhA values of the nutritional risk group and the malnourished group were significantly lower than those of the well-nourished group (p < 0.05). PhA positively correlated with patients' nutrition status. Nineteen patients had postoperative complications, and the PhA value of the complication group was significantly lower than that of the non-complication group (4.94 vs. 5.47, p = 0.013). ROC curves showed that the cutoff point of PhA to predict malnutrition was 5.45 (AUC: 0.744), and the cutoff point of PhA to predict postoperative complications was 5.35 (AUC: 0.717). Our study indicates that PhA was associated with nutrition status and could be considered a nutrition assessment tool for pancreatic head cancer patients and predict the postoperative complications of these patients who have undergone PD.


Sujet(s)
Malnutrition , Tumeurs du pancréas , Impédance électrique , Humains , Malnutrition/complications , Malnutrition/épidémiologie , Évaluation de l'état nutritionnel , État nutritionnel , Tumeurs du pancréas/complications , Tumeurs du pancréas/chirurgie , Complications postopératoires/épidémiologie , Études prospectives , Tumeurs du pancréas
5.
Dis Markers ; 2022: 9737587, 2022.
Article de Anglais | MEDLINE | ID: mdl-35756487

RÉSUMÉ

Pancreatic cancer (PC) is notorious for its parallel morbidity and mortality rates. Recently, necroptosis, a form of programmed cell necrosis, has gained popularity for its role in tumorigenesis and metastasis. In this study, we explored the expression of necroptosis-related genes in PC and normal pancreatic tissues and identified 52 differentially expressed genes (DEGs). The Cox regression analysis was applied to construct the prognostic risk model, which divided patients into high- and low-risk groups. PC patients in the low-risk group showed a significantly better overall survival (OS) than those in the high-risk group. We further validated the prognostic role in ICGC cohort. Further, Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), Gene Set Enrichment Analysis (GSEA), and tumor microenvironment (TME) analysis were used to explore the underlying mechanisms. Notably, based on the gene signature, we revealed that the risk score was strongly related to the sensitivity of chemotherapy. In conclusion, necroptosis-related genes serve as an important immune mediator, and the risk model could be used to predict the survival and to guide the development of precision drugs for patients with PC.


Sujet(s)
Tumeurs du pancréas , Microenvironnement tumoral , Humains , Nécroptose/génétique , Tumeurs du pancréas/génétique , Pronostic , Microenvironnement tumoral/génétique , Tumeurs du pancréas
6.
Article de Anglais | MEDLINE | ID: mdl-35368770

RÉSUMÉ

Proteins provide the main building blocks for tissue growth, cell renewal, and repair during wound healing. We aimed to examine the effect of a compound protein on wound healing, nutritional status, and underlying mechanisms. We first performed a preliminary experiment to identify the appropriate wound healing assessment points. In the formal experiment, there were five groups (control group: 8.3750 g/kg/day saline solution; model group: 8.3750 g/kg/day saline solution; whey protein group: 8.3750 g/kg/day whey protein; low-dose compound protein group: 4.1875 g/kg/day compound protein; and high-dose compound protein group: 8.3750 g/kg/day compound protein) with eight rats in each group. At each turning point, we observed the wound healing rate and nutritional status of the different groups of rats. In addition, biochemical assays were used to determine the mechanisms underlying the effects of the compound protein. In the preliminary experiment, the third day after modeling was the turning point between the inflammatory and proliferation phases, and the eighth day was the turning point between the proliferation and remodeling phases. The formal experiment evaluated wound healing condition, inflammatory response, angiogenesis, collagen deposition, and nutritional status. A pathological report showed increased vascularization, collagen deposition, and epithelialization in compound protein-treated groups. Protein-treated mice showed decreased interleukin (IL)-6, IL-8, neutrophils, and lymphocytes and increased IL-10, albumin, prealbumin, total protein levels, insulin-like growth factor 1 (IGF-1), fibroblast growth factor 2 (FGF-2), and vascular endothelial growth factor (VEGF) expressions. All parameters were significant (p < 0.05) compared to the model group. There was a dose-dependent effect of the compound protein. The accelerated wound healing mechanism may be that the compound protein accelerates the whole wound healing process, making wounds transition from the inflammatory phase to the proliferation phase faster, entering the remodeling phase earlier. Administration of a compound protein can accelerate wound healing and improve the nutritional status.

7.
Cell Mol Immunol ; 19(1): 67-78, 2022 01.
Article de Anglais | MEDLINE | ID: mdl-34845370

RÉSUMÉ

The global coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused severe morbidity and mortality in humans. It is urgent to understand the function of viral genes. However, the function of open reading frame 10 (ORF10), which is uniquely expressed by SARS-CoV-2, remains unclear. In this study, we showed that overexpression of ORF10 markedly suppressed the expression of type I interferon (IFN-I) genes and IFN-stimulated genes. Then, mitochondrial antiviral signaling protein (MAVS) was identified as the target via which ORF10 suppresses the IFN-I signaling pathway, and MAVS was found to be degraded through the ORF10-induced autophagy pathway. Furthermore, overexpression of ORF10 promoted the accumulation of LC3 in mitochondria and induced mitophagy. Mechanistically, ORF10 was translocated to mitochondria by interacting with the mitophagy receptor Nip3-like protein X (NIX) and induced mitophagy through its interaction with both NIX and LC3B. Moreover, knockdown of NIX expression blocked mitophagy activation, MAVS degradation, and IFN-I signaling pathway inhibition by ORF10. Consistent with our observations, in the context of SARS-CoV-2 infection, ORF10 inhibited MAVS expression and facilitated viral replication. In brief, our results reveal a novel mechanism by which SARS-CoV-2 inhibits the innate immune response; that is, ORF10 induces mitophagy-mediated MAVS degradation by binding to NIX.


Sujet(s)
COVID-19/génétique , COVID-19/virologie , Immunité innée/immunologie , Cadres ouverts de lecture , SARS-CoV-2/génétique , Transduction du signal , Protéines adaptatrices de la transduction du signal/métabolisme , Antiviraux/métabolisme , Autophagie/immunologie , Extinction de l'expression des gènes , Cellules HEK293 , Cellules HeLa , Humains , Interféron de type I/métabolisme , Mitochondries/métabolisme , Mitophagie , Proteasome endopeptidase complex/métabolisme , Ubiquitination , Protéines virales/métabolisme , Réplication virale
8.
Bioengineered ; 12(1): 3634-3646, 2021 12.
Article de Anglais | MEDLINE | ID: mdl-34252356

RÉSUMÉ

The extracellular matrix (ECM) shows an essential effect during the occurrence and procession of human cancers. Type III collagen is a crucial component of ECM. Collagen Type III Alpha 1(COL3A1) is aberrantly expressed in a variety of cancers. Nevertheless, the role of COL3A1 in pan-cancer stays unidentified. In this study, we explored public databases, including Cancer Genome Atlas (TCGA), GTEx, GEPIA, cBioPortal, Oncommine, TIMER and GENEMANIA databases to identify the differential expression of COL3A1 in human cancer tissues and normal samples, followed by its prognostic value for patient survival. In addition, we explore the association between COL3A1 expression and immune infiltration. Further, we used the GeneMANIA database and Gene Set Enrichment Analysis (GSEA) to investigate Protein-Protein Interaction (PPI) and gene functional enrichment. Results show that COL3A1 expressed higher in tumor samples than in normal samples. Upregulation of COL3A1 is associated with a worse prognosis and a more advanced cancer stage. COL3A1 expression shows significant positive correlations with tumor-infiltrating immune cells (TIICs), including neutrophils, macrophages, CD8 + T cells, CD4 + T cells, dendritic cells, and B cells. Markers of TIICs demonstrated distinct patterns of COL3A1-related immune infiltration. COL3A1 expression was associated with ECM receptor interaction, regulation of actin cytoskeleton and focal adhesion pathways via GSEA analysis. In conclusion, COL3A1 may be a molecular biomarker for prognosis and immune infiltration in pan-cancer. It might act as a potential target for a new insight of human cancers management.


Sujet(s)
Collagène de type III , Tumeurs , Collagène de type III/génétique , Collagène de type III/immunologie , Collagène de type III/métabolisme , Fouille de données , Humains , Tumeurs/génétique , Tumeurs/immunologie , Tumeurs/métabolisme , Tumeurs/mortalité , Pronostic , Cartes d'interactions protéiques/génétique , Transcriptome/génétique
9.
Public Health Nutr ; 24(15): 4786-4795, 2021 10.
Article de Anglais | MEDLINE | ID: mdl-33820577

RÉSUMÉ

OBJECTIVE: Individuals with HIV are at increased risk for osteoporosis. A healthy diet with adequate Ca is recommended to promote bone health. However, lengthy nutritional assessments pose barriers to routine screenings in clinical practice. This study aimed to examine the validity and reproducibility of a six-item dietary Ca screening tool among Chinese individuals with HIV. DESIGN: We conducted a two time-point study in an outpatient setting. Volunteers self-administered the six-item tool upon enrolment and again at 1-month follow-up. At baseline, participants also completed a validated FFQ and surveys regarding demographic and clinical risk factors. SETTING: Beijing, China; Shenzhen, Guangdong, China. PARTICIPANTS: Upon enrolment, 127 individuals with HIV participated in the study, of whom 83 completed the follow-up screening. RESULTS: Mean age of participants was 35·2 (sd 9·3) years, average BMI was 22·8 (sd 3·8) kg/m2 and 89 % were men. Among the participants, 54·7 % reported Ca intake less than 800 mg/d. The six-item tool demonstrated fair-to-moderate relative validity with a correlation of 0·39 and 75·7 % of subjects classified in same/adjacent quartiles as the reference, and moderate-to-good reproducibility with a correlation of 0·60 and 83·1 % of subjects classified in same/adjacent quartiles. Finally, receiver operating characteristic analyses yielded a sensitivity of 87·0 % and a specificity of 39·4 % with optimised cut-off level. CONCLUSIONS: The six-item tool presented adequate validity and reproducibility to identify individuals with low Ca intake among the target population, providing a convenient instrument for categorising Ca intake in clinical practice, prompting referrals for further assessment, and raising awareness of dietary Ca in bone disease prevention.


Sujet(s)
Calcium alimentaire , Infections à VIH , Adulte , Chine , Journaux alimentaires , Enquêtes sur le régime alimentaire , Humains , Mâle , Reproductibilité des résultats
10.
Mol Med Rep ; 22(2): 1351-1361, 2020 08.
Article de Anglais | MEDLINE | ID: mdl-32626962

RÉSUMÉ

Myocardial ischemia­reperfusion (MI/R) injury is a complex pathological process that occurs when tissues are reperfused following a prolonged period of ischemia. Troxerutin has been reported to have cardioprotective functions. However, the underlying mechanism by which troxerutin protects against MI/R injury has not been fully elucidated. The aim of the present study was to explore whether troxerutin­mediated protection against oxygen­glucose deprivation/reoxygenation (OGD/R)­induced H9C2 cell injury was associated with the inhibition of oxidative stress and the inflammatory response by regulating the PI3K/AKT/hypoxia­inducible factor­1α (HIF­1α) signaling pathway. The results of the present study suggested that troxerutin pretreatment prevented the OGD/R­induced reduction in cell viability, and the increase in lactate dehydrogenase activity and apoptosis. Troxerutin reversed OGD/R­induced the inhibition of the PI3K/AKT/HIF­1α signaling pathway as demonstrated by the increased expression of PI3K and HIF­1α, and the increased ratio of phosphorylated AKT/AKT. LY294002, a selective PI3K inhibitor, inhibited the PI3K/AKT/HIF­1α signaling pathway and further attenuated the protective effect of troxerutin against OGD/R­induced H9C2 cell damage. Furthermore, small interfering (si)RNA­mediated knockdown of HIF­1α reduced troxerutin­induced protection against OGD/R injury. Troxerutin pretreatment alleviated OGD/R­induced oxidative stress, as demonstrated by the reduced generation of reactive oxygen species and malonaldehyde content, and the increased activities of superoxide dismutase and glutathione peroxidase, which were reduced by HIF­1α­siRNA. Troxerutin­induced decreases in the levels of interleukin (IL)­1ß, IL­6 and tumor necrosis factor­α in OGD/R conditions were also reduced by HIF­1α­siRNA. The results from the present study indicated that troxerutin aggravated OGD/R­induced H9C2 cell injury by inhibiting oxidative stress and the inflammatory response. The primary underlying protective mechanism of troxerutin was mediated by the activation of the PI3K/AKT/HIF­1α signaling pathway.


Sujet(s)
Cardiotoniques/pharmacologie , Survie cellulaire/effets des médicaments et des substances chimiques , O-(bêta-Hydroxyéthyl)rutosides/analogues et dérivés , Myocytes cardiaques/effets des médicaments et des substances chimiques , Stress oxydatif/effets des médicaments et des substances chimiques , Transduction du signal/effets des médicaments et des substances chimiques , Animaux , Apoptose/effets des médicaments et des substances chimiques , Lignée cellulaire , O-(bêta-Hydroxyéthyl)rutosides/pharmacologie , Sous-unité alpha du facteur-1 induit par l'hypoxie/métabolisme , Lésion de reperfusion myocardique/traitement médicamenteux , Phosphatidylinositol 3-kinases/métabolisme , Protéines proto-oncogènes c-akt/métabolisme , Rats , Espèces réactives de l'oxygène/métabolisme
11.
Food Funct ; 11(2): 1425-1440, 2020 Feb 26.
Article de Anglais | MEDLINE | ID: mdl-31971191

RÉSUMÉ

Although Parkinson's disease (PD) is the second most common neurodegenerative disorder, the preventative or therapeutic agents for the treatment of PD are limited. Eucommia ulmoides Oliver (EuO) is widely used as a traditional herb to treat various diseases. EuO bark extracts have been reported to possess anti-PD activity. Here, we investigated whether extracts of EuO leaves (EEuOL) also have therapeutic effects on PD since similar components and clinical applications have been found between barks and leaves of this tree. We identified the chemical composition of EEuOL by HPLC-Q-TOF-MS and tested the anti-PD effect of EEuOL using the zebrafish PD model. As a result, 28 compounds including 3 phenolic acids, 7 flavonoids, and 9 iridoids were identified. EEuOL significantly reversed the loss of dopaminergic neurons and neural vasculature and reduced the number of apoptotic cells in zebrafish brain in a concentration-dependent manner. Moreover, EEuOL relieved locomotor impairments in MPTP-modeled PD zebrafish. We also investigated the underlying mechanism and found that EEuOL may activate autophagy, contributing to α-synuclein degradation, therefore alleviating PD-like symptoms. Molecular docking simulation implied the interaction between autophagy regulators (Pink1, Beclin1, Ulk2, and Atg5) and phenolic acids of EEuOL, affirming the involvement of autophagy in EEuOL-exerted anti-PD action. The overall results indicated the anti-PD effect of EEuOL, opening the possibility to use the extract in PD treatment.


Sujet(s)
Eucommiaceae , Hydroxybenzoates/pharmacologie , Activité motrice/effets des médicaments et des substances chimiques , Maladie de Parkinson/traitement médicamenteux , Extraits de plantes/pharmacologie , Animaux , Autophagie/effets des médicaments et des substances chimiques , Modèles animaux de maladie humaine , Phytothérapie , Feuilles de plante , Danio zébré
12.
Clin Nutr ; 39(6): 1724-1734, 2020 06.
Article de Anglais | MEDLINE | ID: mdl-31466731

RÉSUMÉ

BACKGROUND: Obesity is a well-known risk factor of type 2 diabetes mellitus (T2DM), and it is commonly accompanied by T2DM. It is estimated that almost two thirds of the population with T2DM is also affected by hypertension. Elevated arterial blood pressure would increase the risk for diabetes development. Recently some studies indicated that a high-protein diet was effective for weight loss, and therefore we hypothesized that a high-protein diet could help control blood glucose, mitigate insulin resistance (IR) and improve blood pressure by weight management in T2DM patients. AIM: The study aimed to systematically review the effects of a high-protein diet on glycemic control, IR and blood pressure in T2DM patients. METHODS: We searched four electronic databases until May 1st 2018 and included all randomized clinical trials comparing a high-protein diet with other diets. Two reviewers independently identified the trials for inclusion and independently extracted data. Either a fixed- or a random-effects model was used to combine the changes in each outcome from baseline to the end of the intervention. The meta-analysis was performed with RevMan 5.3 software. RESULTS: Twelve articles (thirteen studies) including 1138 T2DM patients met our inclusion criteria. Glycemic control was not significantly different between the high-protein diet and control group, with the changes in fasting plasma glucose (FPG) (-0.13 (95% CI (-0.46, 0.19), p = 0.43) mmol/L) and HbA1c% (-0.05 (95% CI (-0.18, 0.08, p = 0.92))) from baseline to the end of intervention. However, the difference in IR between the two groups was statistically significant. Most changes in lipids profiles were favorable. The changes in HDL, LDL, TC, and TG were +0.03 (95% CI (-0.04,0.11), p = 0.35) mmol/L, -0.10 (95% CI (-0.18, -0.02), p = 0.02) mmol/L, -0.21 (95% CI (-0.31, -0.12), p < 0.01) mmol/L and -0.19 (95% CI (-0.33, -0.05), p < 0.01) mmol/L, respectively. The result of HOMA-IR was -0.27 (95% CI (-0.47, -0.06), p < 0.01). Additionally, the difference in blood pressure in terms of systolic blood pressure (-0.57 (95% CI (-2.45, 1.32), p = 0.55)) and diastolic blood pressure (-0.73 (95% CI (-2.48, 1.02), p = 0.41)) was not significant. CONCLUSION: This review showed that a high-protein diet does not significantly improve glycemic control and blood pressure, but can lower LDL, TC, TG and HOMA-IR levels in T2DM patients. Further studies are needed to clarify the effects of a high-protein diet on glycemic control, IR and blood pressure control in T2DM patients.


Sujet(s)
Glycémie/métabolisme , Pression sanguine , Diabète de type 2/diétothérapie , Régime riche en protéines , Régulation de la glycémie , Insulinorésistance , Sujet âgé , Marqueurs biologiques/sang , Diabète de type 2/sang , Diabète de type 2/diagnostic , Diabète de type 2/physiopathologie , Régime riche en protéines/effets indésirables , Femelle , Régulation de la glycémie/effets indésirables , Humains , Insuline/sang , Lipides/sang , Mâle , Adulte d'âge moyen , Essais contrôlés randomisés comme sujet , Résultat thérapeutique , Perte de poids
13.
Carbohydr Polym ; 133: 294-301, 2015 Nov 20.
Article de Anglais | MEDLINE | ID: mdl-26344284

RÉSUMÉ

An alkali-soluble single-component polysaccharide, named CPTC-2, was isolated and purified from the leaves of Taxus chinensis var. mairei. by ion-exchange and gel-permeation chromatography in series. The weight-average molecular mass (Mw) of CPTC-2 was about 73.53kDa determined by gel permeation chromatography (GPC). The structural characteristics of CPTC-2 were analyzed by gas chromatography (GC), Infrared (IR) spectrum, nuclear magnetic resonance (NMR) spectroscopy, periodate oxidation and Smith degradation studies, as well as methylation analysis. The results showed that CPTC-2 consisted of glucose, mannose, xylose, arabinose, rhamnose, and galactose with a molar ratio of 1.00:0.32:0.27:3.34:1.22:1.84. CPTC-2 was mainly composed of one type of sugar, α-glycosidic linkage. It had a backbone composed of α-(1→3) Araf, α-(1→5) Araf and α-(1→4) Galp with branches composed of α-(1→3,5) Araf and ß-(1→3,6) Manp. In vitro anti-tumor experiments with SGC-7901 cells were performed and assessed by MTS (MPEG-2 Transport Stream) method and flow cytometry. The results showed CPTC-2 could inhibit the growth of SGC-7901 cells in a concentration-dependent manner via increased apoptosis. The relationship between the structure of CPTC-2 and its anti-tumor activity indicated that the α-configuration glycosidic bond residues may be essential for the anti-tumor activity of this polysaccharide.


Sujet(s)
Antinéoplasiques/composition chimique , Antinéoplasiques/pharmacologie , Polyosides/composition chimique , Polyosides/pharmacologie , Taxus/composition chimique , Lignée cellulaire tumorale , Prolifération cellulaire/effets des médicaments et des substances chimiques , Humains , Méthylation , Oxydoréduction , Acide orthoperiodique/composition chimique
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