Identification of hub genes associated with Helicobacter pylori infection and type 2 diabetes mellitus:A pilot bioinformatics study

BACKGROUND Helicobacter pylori(H.pylori)infection is related to various extragastric diseases including type 2 diabetes mellitus(T2DM).However,the possible mechanisms connecting H.pylori infection and T2DM remain unknown.AIM To explore potential molecular connections between H.pylori infection and T2DM.METHODS We extracted gene expression arrays from three online datasets(GSE60427,GSE27411 and GSE115601).Differentially expressed genes(DEGs)commonly present in patients with H.pylori infection and T2DM were identified.Hub genes were validated using human gastric biopsy samples.Correlations between hub genes and immune cell infiltration,miRNAs,and transcription factors(TFs)were further analyzed.RESULTS A total of 67 DEGs were commonly presented in patients with H.pylori infection and T2DM.Five significantly upregulated hub genes,including TLR4,ITGAM,C5AR1,FCER1G,and FCGR2A,were finally identified,all of which are closely related to immune cell infiltration.The gene-miRNA analysis detected 13 miRNAs with at least two gene cross-links.TF-gene interaction networks showed that TLR4 was coregulated by 26 TFs,the largest number of TFs among the 5 hub genes.CONCLUSION We identified five hub genes that may have molecular connections between H.pylori infection and T2DM.This study provides new insights into the pathogenesis of H.pylori-induced onset of T2DM.

miR-1298-5p通过靶向MSH2基因对非小细胞肺癌细胞生物学行为及肿瘤免疫微环境的影响

目的:探究miR-1298-5p在非小细胞肺癌(NSCLC)中调节MSH2基因的潜在机制及对肿瘤细胞生物学行为和肿瘤免疫微环境的影响。方法:采用生物信息学手段确定NSCLC中涉及的关键基因和miRNA。采用CCK-8检测细胞增殖能力,Transwell实验检测细胞侵袭、迁移能力。ELISA检测炎症因子的水平。Western blot测定细胞内中MSH2的表达情况,荧光定量聚合酶链反应(RT-qPCR)检测NSCLC细胞中miR-1298-5p和MSH2基因表达。双荧光素酶报告基因实验验证miR-1298-5p与MSH2的靶向关系。Spearman相关性分析miR-1298-5p与肿瘤免疫微环境中免疫细胞和免疫因子的相关性。结果:与正常肺部组织细胞相比,NSCLC细胞中miR-1298-5p水平下调。miR-1298-5p过表达可抑制NSCLC细胞的增殖、迁移和侵袭。使用荧光素酶报告基因检测证实MSH2是miR-1298-5p的靶基因。此外,NSCLC细胞中miR-1298-5p的下调可通过沉默MSH2来逆转。miR-1298-5p的表达水平与Treg、IL-10和TGF-β水平呈负相关,与CD3^(+)T、CD4^(+)T、CD8^(+)T、NK细胞、IL-2和IFN-γ水平呈正相关。结论:miR-1298-5p负性调控MSH2抑制NSCLC细胞的增殖、侵袭及迁移,并改善肿瘤免疫微环境。

Regulatory potential of soil available carbon,nitrogen,and functional genes on N_(2)O emissions in two upland plantation systems

Dynamic nitrification and denitrification processes are affected by changes in soil redox conditions,and they play a vital role in regulating soil N_(2)O emissions in rice-based cultivation.It is imperative to understand the influences of different upland crop planting systems on soil N_(2)O emissions.In this study,we focused on two representative rotation systems in Central China:rapeseed–rice(RR)and wheat–rice(WR).We examined the biotic and abiotic processes underlying the impacts of these upland plantings on soil N_(2)O emissions.The results revealed that during the rapeseed-cultivated seasons in the RR rotation system,the average N_(2)O emissions were 1.24±0.20 and 0.81±0.11 kg N ha^(–1)for the first and second seasons,respectively.These values were comparable to the N_(2)O emissions observed during the first and second wheat-cultivated seasons in the WR rotation system(0.98±0.25 and 0.70±0.04 kg N ha^(–1),respectively).This suggests that upland cultivation has minimal impacts on soil N_(2)O emissions in the two rotation systems.Strong positive correlations were found between N_(2)O fluxes and soil ammonium(NH_(4)^(+)),nitrate(NO_(3)^(–)),microbial biomass nitrogen(MBN),and the ratio of soil dissolved organic carbon(DOC)to NO_(3)^(–)in both RR and WR rotation systems.Moreover,the presence of the AOA-amoA and nirK genes were positively associated with soil N_(2)O fluxes in the RR and WR systems,respectively.This implies that these genes may have different potential roles in facilitating microbial N_(2)O production in various upland plantation models.By using a structural equation model,we found that soil moisture,mineral N,MBN,and the AOA-amoA gene accounted for over 50%of the effects on N_(2)O emissions in the RR rotation system.In the WR rotation system,soil moisture,mineral N,MBN,and the AOA-amoA and nirK genes had a combined impact of over 70%on N_(2)O emissions.These findings demonstrate the interactive effects of functional genes and soil factors,including soil physical characteristics,available carbon and nitrogen,and their ratio,on soil N_(2)O emissions during upland cultivation seasons under rice-upland rotations.

Pathogenesis of chronic enteropathy associated with the SLCO2A1 gene:Hypotheses and conundrums

Chronic enteropathy associated with the SLCO2A1 gene(CEAS)is a complex gastroenterological condition characterized by multiple ulcers in the small intestine with chronic bleeding and protein loss.This review explores the potential mechanisms underlying the pathogenesis of CEAS,focusing on the role of SLCO2A1-encoded prostaglandin transporter OATP2A1 and its impact on prostaglandin E2(PGE2)levels.Studies have suggested that elevated PGE2 levels contribute to mucosal damage,inflammation,and disruption of the intestinal barrier.The effects of PGE2 on macrophage activation and Maxi-Cl channel functionality,as well as its interaction with nonsteroidal anti-inflammatory drugs play crucial roles in the progression of CEAS.Understanding the balance between its protective and pro-inflammatory effects and the complex interactions within the gastrointestinal tract can shed light on potential therapeutic targets for CEAS and guide the development of novel,targeted therapies.

胃癌组织中MLH1,MSH2,MSH6和PMS2表达及与临床病理特征和预后的相关性分析

目的探讨胃癌组织中错配修复蛋白MutL homologue 1(MLH1),MutS homologue 2(MSH2),MutS homologue 6(MSH6)和减数分裂后分离为2(postmeiotic segregation increased 2,PMS2)的表达及与临床病理特征和预后的相关关系。方法选取承德医学院附属医院病理科2018年11月~2021年11月确诊的474例胃癌组织为研究对象,采用免疫组织化学SP法检测胃癌组织中MLH1,MSH2,MSH6和PMS2蛋白表达水平,根据此四种蛋白表达情况将胃癌组织分为高频微卫星不稳定(microsatellite instability-high,MSI-H)组和低频微卫星不稳定或微卫星稳定(microsatellite instability-low/microsatellite stability,MSI-L/MSS)组,比较两组的临床病理特点。采用Kaplan-Meier生存分析法比较两组患者的预后情况。结果474例胃癌中,MSI-L/MSS型胃癌为403例(85.02%),MSI-H型胃癌共71例(14.98%)。其中4种错配修复蛋白MLH1,MSH2,MSH6和PMS2任一表达缺失共42例,占8.86%(42/474);两种及以上蛋白表达缺失共29例,占6.12%(29/474);MLH1,MSH2和PMS2同时表达缺失率0.84%(4/474);MLH1,MSH2,MSH6和PMS2全部表达缺失率0.21%(1/474)。MSI-H型胃癌患者淋巴结转移率和脉管侵犯率低于MSI-L/MSS型胃癌,差异具有统计学意义(χ^(2)=21.65,8.93,均P<0.05)。而两组患者在性别、年龄、Borramn分型、Lauren分型、分化程度、浸润深度和远处转移等方面比较,差异均无统计学意义(χ^(2)=0.03~2.79,均P>0.05)。MSI-H型与MSI-L/MSS型胃癌患者相比,三年总生存率(overall survival,OS)为87.52%和62.68%,差异无统计学意义(χ^(2)=3.64,P>0.05),三年无进展生存率(progression-free survival,PFS)为75.00%和57.84%,差异无统计学意义(χ^(2)=3.21,P>0.05)。结论与MSI-L/MSS型胃癌相比,MSI-H型胃癌患者淋巴结的转移率低和脉管的侵犯率低,三年OS和PFS偏高,提示MSI-H型胃癌患者有较好的预后。

Identification of M2 macrophage-related genes for establishing a prognostic model in pancreatic cancer: FCGR3A as key gene

Background:Pancreatic ductal adenocarcinoma(PDAC)has a rich and complex tumor immune microenvironment(TIME).M2 macrophages are among the most extensively infiltrated immune cells in the TIME and are necessary for the growth and migration of cancers.However,the mechanisms and targets mediating M2 macrophage infiltration in pancreatic cancer remain elusive.Methods:The M2 macrophage infiltration score of patients was assessed using the xCell algorithm.Using weighted gene co-expression network analysis(WGCNA),module genes associated with M2 macrophages were identified,and a predictive model was designed.The variations in immunological cell patterns,cancer mutations,and enrichment pathways between the cohorts with the high-and low-risk were examined.Additionally,the expression of FCGR3A and RNASE2,as well as their association with M2 macrophages were evaluated using the HPA,TNMplot,and GEPIA2 databases and verified by tissue immunofluorescence staining.Moreover,in vitro cell experiments were conducted,where FCGR3A was knocked down in pancreatic cancer cells using siRNA to analyze its effects on M2 macrophage infiltration,tumor proliferation,and metastasis.Results:The prognosis of patients in high-risk and low-risk groups was successfully distinguished using a prognostic risk score model of M2 macrophage-related genes(p=0.024).Between the high-and low-risk cohorts,there have been notable variations in immune cell infiltration patterns,tumor mutations,and biological functions.The risk score was linked to the manifestation of prevalent immunological checkpoints,immunological scores,and stroma values(all p<0.05).In vitro experiments and tissue immunofluorescence staining revealed that FCGR3A can promote the infiltration or polarization of M2 macrophages and enhance tumor proliferation and migration.Conclusions:In this study,an M2 macrophage-related pancreatic cancer risk score model was established,and found that FCGR3A was correlated with tumor formation,metastasis,and M2 macrophage infiltration.

结直肠癌组织中ARID1A基因突变和MSH2蛋白表达与临床病理特征及预后的相关性

目的:检测结直肠癌(CRC)组织中富含AT结合域1A(ARID1A)基因突变和mutS同种组织蛋白2(MSH2)蛋白表达,分析两者的临床意义。方法:选取自2017年1月至2018年1月期间我院诊治的142例CRC患者作为研究对象。采用直接测序法检测CRC癌组织中ARID1A基因突变。免疫组化检测癌及癌旁组织MSH2蛋白表达。Spearman秩相关分析ARID1A基因突变和MSH2蛋白表达的相关性。统计学分析ARID1A基因突变、MSH2蛋白表达与CRC临床病理特征的关系。Kaplan-Meier生存分析ARID1A基因突变和MSH2蛋白表达对患者生存预后的影响。单因素及多因素Cox回归分析影响CRC患者生存预后的因素。结果:142例CRC癌组织中,27例发生ARID1A基因突变,ARID1A基因突变率为19.01%(27/142)。MSH2棕黄色阳性表达主要位于细胞核。CRC癌组织中MSH2阳性率为51.41%(73/142),明显低于癌旁组织91.55%(130/142)(χ^(2)=56.116,P=0.000)。不同肿瘤TNM分期、淋巴结转移CRC癌组织中ARID1A基因突变、MSH2阳性率差异具有统计学意义(P<0.05)。CRC癌组织中ARID1A基因突变和MSH2表达呈显著负相关性(r=-0.575,P=0.000)。ARID1A基因突变组患者3年总体生存率为37.04%(10/27),明显低于野生型组患者67.27%(74/110)(P=0.000);MSH2阳性表达组患者3年总体生存率为81.43%(57/70),明显高于阴性表达组患者42.30%(27/67)(P=0.000)。ARID1A基因突变型、MSH2阴性表达、肿瘤TNM分期Ⅲ期及伴淋巴结转移是影响CRC患者预后的独立危险因素(P<0.05)。结论:ARID1A基因、MSH2表达与CRC患者肿瘤分期及淋巴结转移有关,是CRC患者预后预测的独立因素。

Detections of mefA, ermB, and mphA Macrolides Resistant Genes in Bacteria Isolated from Covid-19 Patients from Selected Health Facilities in Ibadan, Nigeria

Background: COVID-19 is a disease caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Epidemiological data indicated that bacterial complications in COVID-19 would decrease clearance rate of the infecting agent and increase mortality rate. Macrolides such as Azithromycin are usually administered to COVID-19 patients as palliative treatments. Currently, a considerable number of bacterial strains have developed resistance to various antibiotics, especially macrolides. Resistance is reported to be due to possession of mefA, ermB, and mphA genes by Gram positive and Gram negative bacteria. Therefore, this study determined antibiotic resistance patterns and identify mefA, ermB and mphA macrolide-resistant genes in bacterial pathogens isolated from COVID-19 cases in Ibadan, Nigeria. Methods: 400 Nasopharyngeal samples were collected from symptomatic cases before antibiotic medication;structured questionnaires were administered to collect socio-demographic data of participants. Samples were cultured on Blood, Chocolate, MacConkey and Mannitol salt agar at 37°C for 48 hrs. Bacterial identification was performed using VITEK 2.0 ID cards and API 20E for Gram positive and negative bacteria respectively. Antibiotic Susceptibility Testing was performed using Kirby Bauer disc diffusion methods and VITEK 2.0 AST card kits. DNA of multidrug resistant bacterial isolates was extracted;resistant genes were determined using a polymerase chain reaction with specific primers. Amplified genes were detected using agarose gel electrophoresis. Results: 240 (60%) had bacterial growth and 97 (22.2%) yielded no growth. From the 240 bacterial isolates, 38 (15.83%) were multi-drug resistant including resistance to macrolides (Azithromycin) 20 (52.63%) of which were positive for either mefA or ermB, and none (0.0%) possess mphA gene;14 (36.8%) isolates had mefA gene, 10 (26.3%) isolates carried ermB gene. Conclusion: Multi-drug bacterial resistance including macrolides and quinolones was detected. Only mefA and ermB genes were detected in the bacterial isolates, especially in Gram positive organisms. The detection of mefA and ermB genes in the MDR bacterial isolates raised concern on the use of azithromycin as palliative treatment for COVID-19 symptomatic patients.

Trifunctional Cu-Mesh/Cu_(2)O@FeO Nanoarrays for Highly Efficient Degradation of Antibiotic, Inactivation of Antibiotic-Resistant Bacteria, and Damage of Antibiotics Resistance Genes

Trifunctional Cu-mesh/Cu_(2)O@FeO nanoarrays heterostructure is designed and fabricated by integrating CuCu_(2)O@FeO nanoarrays onto Cu-mesh(CM)via an in situ growth and phase transformation process.It is successfully applied to efficiently mitigate the antibiotic pollution,including degradation of antibiotics,inactivation of antibiotic-resistant bacteria(ARB),and damage of antibiotics resistance genes(ARGs).Under visible-light irradiation,CM/CuCu_(2)O@FeO nanoarrays exhibit a superior degradation efficiency on antibiotics(e.g.,up to 99%in 25 min for tetracycline hydrochloride,TC),due to the generated reactive oxygen species(ROS),especially the dominant·O^(2−).It can fully inactivate E.coli(HB101)with initial number of~108 CFU mL^(−1) in 10 min,which is mainly attributed to the synergistic effects of 1D nanostructure,dissolved metal ions,and generated ROS.Meanwhile,it is able to damage ARGs after 180 min of photodegradation,including tetA(vs TC)of 3.3 log 10,aphA(vs kanamycin sulfate,KAN)of 3.4 log 10,and tnpA(vs ampicillin,AMP)of 4.4 log 10,respectively.This work explores a green way for treating antibiotic pollution under visible light.

Identification of key genes and biological pathways in lung adenocarcinoma by integrated bioinformatics analysis

BACKGROUND The objectives of this study were to identify hub genes and biological pathways involved in lung adenocarcinoma(LUAD)via bioinformatics analysis,and investigate potential therapeutic targets.AIM To determine reliable prognostic biomarkers for early diagnosis and treatment of LUAD.METHODS To identify potential therapeutic targets for LUAD,two microarray datasets derived from the Gene Expression Omnibus(GEO)database were analyzed,GSE3116959 and GSE118370.Differentially expressed genes(DEGs)in LUAD and normal tissues were identified using the GEO2R tool.The Hiplot database was then used to generate a volcanic map of the DEGs.Weighted gene co-expression network analysis was conducted to cluster the genes in GSE116959 and GSE-118370 into different modules,and identify immune genes shared between them.A protein-protein interaction network was established using the Search Tool for the Retrieval of Interacting Genes database,then the CytoNCA and CytoHubba components of Cytoscape software were used to visualize the genes.Hub genes with high scores and co-expression were identified,and the Database for Annotation,Visualization and Integrated Discovery was used to perform enrichment analysis of these genes.The diagnostic and prognostic values of the hub genes were calculated using receiver operating characteristic curves and Kaplan-Meier survival analysis,and gene-set enrichment analysis was conducted.The University of Alabama at Birmingham Cancer data analysis portal was used to analyze relationships between the hub genes and normal specimens,as well as their expression during tumor progression.Lastly,validation of protein expression was conducted on the identified hub genes via the Human Protein Atlas database.RESULTS Three hub genes with high connectivity were identified;cellular retinoic acid binding protein 2(CRABP2),matrix metallopeptidase 12(MMP12),and DNA topoisomerase II alpha(TOP2A).High expression of these genes was associated with a poor LUAD prognosis,and the genes exhibited high diagnostic value.CONCLUSION Expression levels of CRABP2,MMP12,and TOP2A in LUAD were higher than those in normal lung tissue.This observation has diagnostic value,and is linked to poor LUAD prognosis.These genes may be biomarkers and therapeutic targets in LUAD,but further research is warranted to investigate their usefulness in these respects.

Role of p53 suppression in the pathogenesis of hepatocellular carcinoma

In the world,hepatocellular carcinoma(HCC)is among the top 10 most prevalent malignancies.HCC formation has indeed been linked to numerous etiological factors,including alcohol usage,hepatitis viruses and liver cirrhosis.Among the most prevalent defects in a wide range of tumours,notably HCC,is the silencing of the p53 tumour suppressor gene.The control of the cell cycle and the preservation of gene function are both critically important functions of p53.In order to pinpoint the core mechanisms of HCC and find more efficient treatments,molecular research employing HCC tissues has been the main focus.Stimulated p53 triggers necessary reactions that achieve cell cycle arrest,genetic stability,DNA repair and the elimination of DNA-damaged cells’responses to biological stressors(like oncogenes or DNA damage).To the contrary hand,the oncogene protein of the murine double minute 2(MDM2)is a significant biological inhibitor of p53.MDM2 causes p53 protein degradation,which in turn adversely controls p53 function.Despite carrying wt-p53,the majority of HCCs show abnormalities in the p53-expressed apoptotic pathway.High p53 in-vivo expression might have two clinical impacts on HCC:(1)Increased levels of exogenous p53 protein cause tumour cells to undergo apoptosis by preventing cell growth through a number of biological pathways;and(2)Exogenous p53 makes HCC susceptible to various anticancer drugs.This review describes the functions and primary mechanisms of p53 in pathological mechanism,chemoresistance and therapeutic mechanisms of HCC.

Identification and Expression Analysis of Abscisic Acid Signal Transduction Genes in Hemp Seeds

Abscisic acid(ABA)is involved in regulating diverse biological processes,but its signal transduction genes and roles in hemp seed germination are not well known.Here,the ABA signaling pathway members,PYL,PP2C and SnRK2 gene families,were identified from the hemp reference genome,including 7 CsPYL(pyrab-actin resistance1-like,ABA receptor),8 CsPP2CA(group A protein phosphatase 2c),and 7 CsSnRK2(sucrose nonfermenting1-related protein kinase 2).The content of ABA in hemp seeds in germination stage is lower than that in non-germination stage.Exogenous ABA(1 or 10μM)treatment had a significant regulatory effect on the selected PYL,PP2C,SnRK2 gene families.CsAHG3 and CsHAI1 were most significantly affected by exogenous ABA treatment.Yeast two-hybrid experiments were performed to reveal that CsPYL5,CsSnRK2.2,and CsSnRK2.3 could interact with CsPP2CA7 and demonstrate that this interaction was ABA-independent.Our results indicated that CsPYL5,CsSnRK2.2,CsSnRK2.3 and CsPP2CA7 might involve in the ABA signaling transduction pathway of hemp seeds during the hemp seed germination stages.This study suggested that novel genetic views can be brought into investigation of ABA signaling pathway in hemp seeds and lay the foundation for further exploration of the mechanism of hemp seed germination.

Study of pathogenic genes in a pedigree with familial dilated cardiomyopathy

BACKGROUND Dilated cardiomyopathy(DCM)is a genetically heterogeneous cardiac disorder characterized by left ventricular dilation and contractile dysfunction.The substantial genetic heterogeneity evident in patients with DCM contributes to variable disease severity and complicates overall prognosis,which can be very poor.AIM To identify pathogenic genes in DCM through pedigree analysis.METHODS Our research team identified a patient with DCM in the clinic.Through invest-igation,we found that the family of this patient has a typical DCM pedigree.High-throughput sequencing technology,next-generation sequencing,was used to sequence the whole exomes of seven samples in the pedigree.RESULTS A novel and potentially pathogenic gene mutation-ANK2p.F3067L-was discovered.The mutation was completely consistent with the clinical information for this DCM pedigree.Sanger sequencing was used to further verify the locus of the mutation in pedigree samples.These results were consistent with those of high-throughput sequencing.CONCLUSIONS ANK2p.F3067L is considered a novel and potentially pathogenic gene mutation in DCM.

散发性结直肠癌组织中FHIT、MSH2蛋白的异常表达及其临床意义

背景与目的:脆性组氨酸三联体(fragilehistidinetriad,FHIT)蛋白表达缺失是胃肠道肿瘤的频发事件,但在大肠癌却有争议;最近研究表明FHIT蛋白表达失活可能是错配修复蛋白,尤其是mutS同种组织蛋白2(mutShomolog2,MSH2)改变的结果。本研究旨在探讨FHIT、MSH2蛋白在散发性结直肠癌(sporadiccolorectalcarcinoma,SCC)组织中的表达情况及其临床意义。方法:采用免疫组化SP法检测手术切除的84例SCC及其对应癌旁正常结直肠组织和23例肠腺瘤组织标本中FHIT、MSH2蛋白的表达。结果:FHIT蛋白在SCC组织、结直肠腺瘤组织、癌旁正常结直肠组织中阳性率分别为48.81%、73.91%和100%,三者的阳性率差异有显著性(P<0.05)。FHIT蛋白表达水平与SCC患者的年龄、性别及肿瘤部位、组织学类型无关(P>0.05),而与肿瘤浸润深度、分化程度、Dukes分期和淋巴结转移有关(P<0.05),在浸润深度越深、分化程度越低、Dukes分期越晚和有淋巴结转移的癌组织中,FHIT蛋白低表达就越明显;而MSH2蛋白表达水平仅与Dukes分期有关(P<0.05)。SCC中FHIT蛋白表达与MSH2蛋白表达呈正相关(r=0.3728,P<0.01)。结论:(1)FHIT蛋白表达水平与SCC的恶性程度有关,可作为预测SCC浸润转移潜能的一项有意义的生物学指标;(2)SCC中FHIT、MSH2蛋白表达二者之间呈正相关。

错配修复基因hMSH2在宫颈腺癌组织中的表达

目的 :探讨hMSH2基因在人宫颈腺癌组织中的表达及其临床意义。方法 :应用免疫组化链霉菌抗生物素蛋白 过氧化物酶连接法检测 36例宫颈腺癌组织中错配修复基因hMSH2蛋白的表达。结果 :36例宫颈腺癌组织中 10例hMSH2呈阴性 (2 8% ) ,2 6例为阳性表达 (72 % ) ,且与肿瘤分化程度相关 ,分化程度越低阳性率越低 (P <0 .0 5 ) ,hMSH2的表达与肿瘤组织学类型和FIGO分期未见明显关系 (P >0 .0 5 )。结论 :hMSH2基因与宫颈腺癌的发生。

健脾活血方对大鼠胃癌前病变模型CD44V6、MLH1、MSH2表达的影响

目的:通过观察健脾活血方对胃癌前病变大鼠胃黏膜组织中CD44V6、MLH1及MSH2表达的影响,探讨健脾活血方对其干预的作用机制.方法:除正常组外,其他大鼠采用以N-甲基-N-硝基-N-亚硝基胍(N-methyl-N-nitro N-nitrosoguanidine,MNNG)为主同时配合0.3g/L雷尼替丁、400 mL/L乙醇及饥饱失常的多因素造模法建立胃癌前病变动物模型.将造模成功的40只大鼠随机分为模型组(0.9%氯化钠溶液)、胃复春组(0.86 g/kg)、健脾活血方高、中、低剂量组(32、16、8 g/kg),每组8只,每组每天给予等量(10 mL/kg)的不同药物灌胃一次,连续10 wk.实验末处死大鼠,给予相应处理后,快速免疫组织化学检测CD44V6、MLH1及MSH2表达情况.结果:模型组CD44V6表达与正常组相比明显升高(5.12±1.96 vs 0.25±0.46,P<0.01);健脾活血方高、中剂量组CD44V6表达与模型组相比均明显降低(2.25±0.71,3.25±0.31vs 5.12±1.96,P<0.01或P<0.05),低剂量组C D44V6表达与模型组比较差异无统计学意义(P>0.05);健脾活血方高剂量组CD44V6表达与胃复春组相比明显降低(2.25±0.71 vs4.62±1.19,P<0.01),中、低剂量组CD44V6表达与胃复春组比较差异无统计学意义(P>0.05).模型组MLH1、MSH2表达与正常组相比均明显降低(3.75±1.04 vs 8.00±0.926;3.62±1.69 vs 7.25±2.12,P<0.01);健脾活血方高、中、低剂量组MLH1、MSH2表达与模型组相比均明显升高(6.50±0.93,5.25±1.49,5.12±1.25 vs 3.75±1.04;6.62±2.13,6.00±1.51,5.50±1.41 vs 3.62±1.69,P<0.01或P<0.05);健脾活血方高剂量组MLH1表达与胃复春组相比明显升高(6.50±0.93 vs 4.88±1.25,P<0.05),中、低剂量组MLH1及高、中、低剂量组MSH2表达与胃复春组比较差异无统计学意义(P>0.05).结论:健脾活血方可通过降低CD44V6表达,上调MLH1、MSH2表达,减少细胞的非正常侵袭和转移,增强基因的错配修复功能,减少细胞的异常增殖和分化,发挥对大鼠胃癌前病变的治疗作用.

PCR法用于MSH2基因突变的检测

目的:介绍简便、快速、准确的针对一种MSH2新突变基因的诊断方法。方法:根据该MSH2基因突变的位点和特征,设计突变位点特异性引物,进行PCR扩增,电泳检测PCR产物,从而鉴定出该基因突变的携带者或非携带者。结果:用该方法成功检测出遗传性非息肉型直结肠癌家系中的表型正常的MSH2基因新突变携带者。结论:该方法简便、快速、准确又节省成本,可应用于MSH2基因突变的检测。

鼻咽刷洗物MSH2基因甲基化在鼻咽癌早期诊断及预后判断中的作用

目的探讨鼻咽刷洗物检测MSH2基因甲基化在鼻咽癌早期诊断及预后判断中作用。方法运用甲基化特异性PCR检测54例鼻咽癌患者、18例慢性鼻咽炎患者和20例健康志愿者配对鼻咽部组织及鼻咽刷洗物中MSH2基因启动子区甲基化情况。结果鼻咽癌患者鼻咽部癌组织MSH2基因甲基化频率75.9%(41/54),鼻咽刷洗物70.4%(38/54);而在慢性鼻咽炎患者和健康志愿者鼻咽部组织及鼻咽刷洗物中均未检测到MSH2基因启动子甲基化。鼻咽癌组织与鼻咽刷洗物中MSH2基因甲基化密切相关(r=0.87),MSH2基因甲基化与患者临床病理特征无明显相关关系。结论鼻咽刷洗物检测MSH2基因甲基化具有肿瘤特异性,对早期诊断鼻咽癌有一定的临床应用价值,但目前尚不能作为判断鼻咽癌临床预后预测指标。

重铬酸钾对A549细胞MSH2 mRNA及蛋白表达的影响

目的:研究重铬酸钾(K2Cr2O7)对A549细胞MSH2mRNA及蛋白表达的影响。方法:体外培养条件下用0、1.25×10-6、2.50×10-6及5.00×10-6μmol/L的K2Cr2O7溶液染毒A549细胞24h后,分别用MTT法、Real-timePCR及Westernblot方法检测细胞活性、MSH2mRNA及蛋白的表达。结果:随K2Cr2O7作用浓度的升高,A549细胞活性、MSH2mRNA相对表达量和蛋白表达量均逐渐降低(F=175.040、66.128和33.326,P<0.001)。结论:K2Cr2O7影响A549细胞的损伤修复。

DNA错配修复基因MSH2和MLH1单核苷酸多态性与食管癌发生风险相关性研究

目的:探讨DNA错配修复基因MSH2和MLH1单核苷酸多态性对于食管癌易感性的潜在作用。方法:采用医院为基础的病例-对照研究方法,应用PCR-RFLP检测包括正常对照132例,食管癌患者169例MSH2c.2063T>G和MLH1IVS14-19A>G两个基因多态性位点的基因型。通过Logistic回归分析计算出比值比(OR)和95%置信区间(95%CI),估计不同基因型频率分布与食管癌发生风险的关系。结果:MSH2c.2063T>G携带突变等位基因个体发生食管癌的风险是非携带者的3.24倍。MLH1IVS14-19A>G突变等位基因携带者发生食管癌风险是非携带者的1.58倍。对MSH2和MLH1基因交互作用分析发现两突变基因型携带者发生食管癌风险大大增加并具有显著的统计学意义。结论:DNA错配修复基因MSH2c.2063G突变等位基因和MLH1IVS14-19G突变等位基因可能在促成食管癌发生过程起到一定作用。