Primary application of a real-time quantitative polymerase chain reaction for the detection of human breast cancer related novel gene-Metadherin expression

Objective:The aim of this study was to detect the expression level of Metadherin (MTDH) in peripheral blood of the breast cancer patients by real-time fluorescence quantitative polymerase chain reaction (PCR),and to explore the relationship between expression of Metadherin gene in the patients peripheral blood and the clinic-pathological features in breast cancer. Methods:Real-time fluorescence quantitative polymerase chain reaction was employed to determine the expression level of Metadherin gene in 80 peripheral blood samples of breast cancer patients and healthy donors. Results:The expression of Metadherin gene in breast cancer patients peripheral blood were positive,in which 34 breast cancer patients were highly expressed,accounting for 55.7%,while the expression of Metadherin gene in normal females peripheral blood were negative,there was statistical significance (Ratio = 2.02±0.81,P < 0.05); Ratio of the Metadherin expression in breast cancer patients peripheral blood and the glyceraldehyde-3-phosphate dehydrogenase expression was 1.15 ± 0.36. REST software analysis showed that the expression of Metadherin gene was significantly up-regulated in breast cancer. Conclusion:The SYBR Green I quantitative real-time polymerase chain reaction method can successfully detect the expression level of Metadherin gene. Expression level of Metadherin gene in breast cancer patients peripheral blood is closely related to survival,and it maybe involved in the development of breast cancer and used as an indicator of prognosis.

Comparison of Abbott and Da-an real-time PCR for quantitating serum HBV DNA

AIM: To compare the performance of the Da-an real-time hepatitis B virus (HBV) DNA assay and Abbott RealTime HBV assay.

Expression of the B-Cell Lymphoma/Leukemia 11A Gene in Malignant Hematological Cell Lines through Quantitative Reverse Transcription Polymerase Chain Reaction

The B-cell lymphoma/leukemia 11A （BCL11A） gene is essential for normal lymphoid development and has been associated with hematological malignancies. In the current study, the relative expression level of BCL11A in malignant hematological cell lines was evaluated through real-time quantitative reverse transcription polymerase chain reaction （qRT-PCR）. METHODS The relative expression level of BCLllA mRNA in malignant hematological cell lines was determined through qRT- PCR using SYBR Green I dye. Glyceraldehyde-3-phosphate dehydro- genase was used as the reference gene to confirm the relative expression level of BCL11A gene mRNA. RESULTS The relative expression level of BCL11A mRNA in cell lines from B-cell malignancies was significantly higher compared with that from acute rnyeloid leukemia （P 〈 0.05）. Different cell lines with malignant B-cells exhibited a wide range of BCL11A expressions ranging from 27.37 to 93.38. CONCLUSION The overexpression of BCL11A gene mRNA in malignant B-cells might play a role in B-cell lymphoma/leukemia.

Establishment of a new quantitative detection approach to adefovir-resistant HBV and its clinical application

AIM:To establish the more feasible and sensitive assessment approach to the detection of adefovir (ADV) resistance-associated hepatitis B virus (HBV) quasispecies.METHODS: Based on the characteristics of rtA181V/T and rtN236T mutations, a new approach based on real-time fluorescent quantitative polymerase chain reaction (RT-PCR) was established for the detection of ADV-resistant HBV quasispecies, total HBV DNA, rtA181 and rtN236 mutations in blood samples from 32 chronic hepatitis B (CHB) patients with unsatisfactory curative effect on ADV and compared with routine HBV DNA sequencing.RESULTS: Both the sensitivity and specificity of this new detection approach to ADV-resistant HBV quasispecies were 100%, which were much higher than those of direct HBV DNA sequencing. The approach was able to detect 0.1% of mutated strains in a total plasmid population. Among the 32 clinical patients, single rtA181 and rtN236T mutation and double rtA181T and rtN236T mutations were detected in 20 and 8, respectively, while ADV-resistant mutations in 6 (including, rtA181V/T mutation alone in 5 patients) and no associated mutations in 26.CONCLUSION: This new approach is more feasible and efficient to detect ADV-resistant mutants of HBV and ADV-resistant mutations before and during ADV treatment with a specificity of 100% and a sensitivity of 100%.

Quantitative Analysis of ATP Sulfurylase and Selenocysteine Methyltransferase Gene Expression in Different Organs of Tea Plant (<i>Camellia sinensis</i>)

Tea plant (Camellia sinensis) has unique biological features for the study of cellular and molecular mechanisms, an evergreen broad-leaved woody plant which can accumulate selenium in soil abundant of Selenium. Expression of the genes related to Selenium (Se) metabolism is an adaptation to the soil environment for a long period. The purpose of the present study was to explore if there exist differences of expression about these genes in tea plant between growing in Selenium-abundant and normal soil. A quantitative real-time reverse transcription polymerase chain reaction (Q-RT-PCR) assay was done for quantification of ATP sulfurylase (APS) and selenocysteine methyltransferase (SMT) mRNA normalized to Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene in tea plant. Young leaves, mature leaves and tender roots from tea plants growing in soil abundant of Selenium were respectively obtained from Shitai County, Anhui Province, and also the relevant materials of the selenium un-enriched tea plant planted at agricultural garden of Ahui Agriculture University were taken as control for real-time PCR analysis. The results showed that APS1, APS2 and SMT expression levels for either young or mature leaves in selenium-enriched tea plant were lower than that in ordinary (selenium un-enriched) tea plant. In contrast, the APS1, APS2 and SMT expression level of roots in selenium-enriched tea plant were all higher than that in ordinary tea plant. APS1 gene expression level of roots in selenium-enriched tea plant was about 1.6 times higher than that in the ordinary tea plant, APS2 gene expression level was about 4.8-fold higher than that in the ordinary tea plant, SMT gene expression level was about 3.3 times higher than that in the ordinary tea plant. Among various tissues of selenium-enriched tea plant, APS1 gene relative expression level of young leaves was similar to or slightly higher than mature leaves, and the one of roots was the lowest among them;APS2 gene relative expression level of young leaves was similar to or slightly higher than the roots, and the one of mature leaves was the lowest among them;SMT gene relative expression level of young leaves was similar to or slightly higher than mature leaves, and the one of roots was the highest among them. Our results suggest that there existed correlation between selenium and expression levels of these genes.

Quantitative analysis of a panel of gene expression in prostate cancer——with emphasis on NPY expression analysis

Objective： To investigate molecular alterations associating with prostate carcinoma progression and potentially provide information toward more accurate prognosis/diagnosis. Methods： A set of laser captured microdissected （LCM） specimens from 300 prostate cancer （PCa） patients undergoing radical prostatectomy （RP） were defined. Ten patients representing ＂aggressive＂ PCa, and 10 representing ＂non-aggressive＂ PCa were selected based on prostate-specific antigen （PSA） recurrence, Gleason score, pathological stage and tumor cell differentiation, with matched patient age and race between the two groups. Normal and neoplastic prostate epithelial cells were collected with LCM from frozen tissue slides obtained from the RP specimens. The expressions of a panel of genes, including NPY, PTEN, AR, AMACR, DD3, and GSTP1, were measured by quantitative real-time RT-PCR （TaqMan）, and correlation was analyzed with clinicopathological features. Results： The expressions of AMACR and DD3 were consistently up-regulated in cancer cells compared to benign prostate epithelial cells in all PCa patients, whereas GSTP1 expression was down regulated in each patient. NPY, PTEN and AR exhibited a striking difference in their expression patterns between aggressive and non-aggressive PCas （P=0.0203, 0.0284, and 0.0378, respectively, Wilcoxon rank sum test）. The lower expression of NPY showed association with ＂aggressive＂ PCas based on a larger PCa patient cohort analysis （P=0.0037, univariate generalized linear model （GLM） analysis）. Conclusion： Despite widely noted heterogeneous nature of PCa, gene expression alterations ofAM,4CR, DD3, and GSTP1 in LCM-derived PCa epithelial cells suggest for common underlying mechanisms in the initiation of PCa. Lower NPY expression level is significantly associated with more aggressive clinical behavior of PCa; PTEN and AR may have potential in defining PCa with aggressive clinical behavior. Studies along these lines have potential to define PCa-associated gene expression alterations and likely co-regulation of genes/pathways critical in the biology of PCa onset/progression.

Reference genes for quantitative RT-PCR data in gastric tissues and cell lines

AIM:To evaluate the suitability of reference genes in gastric tissue samples and cell lines.METHODS:The suitability of genes ACTB,B2M,GAPDH,RPL29,and 18S rRNA was assessed in21 matched pairs of neoplastic and adjacent nonneoplastic gastric tissues from patients with gastric adenocarcinoma,27 normal gastric tissues from patients without cancer,and 4 cell lines using reverse transcription quantitative real-time polymerase chain reaction(RT-qPCR).The ranking of the best single and combination of reference genes was determined by NormFinder,geNorm,BestKeeper,and DataAssist.In addition,GenEx software was used to determine the optimal number of reference genes.To validate the results,the mRNA expression of a target gene,DNMT1,was quantified using the different reference gene combinations suggested by the various software packages for normalization.RESULTS:ACTB was the best reference gene for all gastric tissues,cell lines and all gastric tissues plus cell lines.GAPDH+B2M or ACTB+B2M was the best combination of reference genes for all the gastric tissues.On the other hand,ACTB+B2M was the best combination for all the cell lines tested and was also the best combination for analyses involving all the gastric tissues plus cell lines.According to the GenEx software,2 or 3 genes were the optimal number of references genes for all the gastric tissues.The relative quantification of DNMT1 showed similar patterns when normalized by each combination of reference genes.The level of expression of DNMT1 in neoplastic,adjacent non-neoplastic and normal gastric tissues did not differ when these samples were normalized using GAPDH+B2M(P=0.32),ACTB+B2M(P=0.61),or GAPDH+B2M+ACTB(P=0.44).CONCLUSION:GAPDH+B2M or ACTB+B2M is the best combination of reference gene for all the gastric tissues,and ACTB+B2M is the best combination for the cell lines tested.

Micro-droplet Digital Polymerase Chain Reaction and Real-Time Quantitative Polymerase Chain Reaction Technologies Provide Highly Sensitive and Accurate Detection of Zika Virus

The establishment of highly sensitive diagnostic methods is critical in the early diagnosis and control of Zika virus(ZIKV)and in preventing serious neurological complications of ZIKV infection. In this study, we established micro-droplet digital polymerase chain reaction(ddPCR) and real-time quantitative PCR(RT-qPCR) protocols for the detection of ZIKV based on the amplification of the NS5 gene. For the ZIKV standard plasmid, the RT-qPCR results showed that the cycle threshold(Ct) value was linear from 10~1 to 10~8 copy/l L, with a standard curve R^2 of 0.999 and amplification efficiency of 92.203%;however, a concentration as low as 1 copy/l L could not be detected. In comparison with RT-qPCR, the dd PCR method resulted in a linear range of 10~1–10~4 copy/l L and was able to detect concentrations as low as 1 copy/l L. Thus, for detecting ZIKV from clinical samples, RT-qPCR is a better choice for high-concentration samples(above 10~1 copy/l L),while ddPCR has excellent accuracy and sensitivity for low-concentration samples. These results indicate that the ddPCR method should be of considerable use in the early diagnosis, laboratory study, and monitoring of ZIKV.

Design and use of group-specific primers and probes for real-time quantitative PCR

Real-time quantitative polymerase chain reaction(qPCR)has gained popularity as a technique to detect and quantify a specific group of target microorganisms from various environmental samples including soil,water,sediments,and sludge.Although qPCR is a very useful technique for nucleic acid quantification,accurately quantifying the target microbial group strongly depends on the quality of the primer and probe used.Many aspects of conducting qPCR assays have become increasingly routine and automated;however,one of the most important aspects,designing and selecting primer and probe sets,is often a somewhat arcane process.In many cases,failed or non-specific amplification can be attributed to improperly designed primer-probe sets.This paper is intended to provide guidelines and general principles for designing group-specific primers and probes for qPCR assays.We demonstrate the effectiveness of these guidelines by reviewing the use of qPCR to study anaerobic processes and biologic nutrient removal processes.qPCR assays using group-specific primers and probes designed with this method,have been used to successfully quantify 16S ribosomal Ribonucleic Acid(16S rRNA)gene copy numbers from target methanogenic and ammoniaoxidizing bacteria in various laboratory-and full-scale biologic processes.Researchers with a good command of primer and probe design can use qPCR as a valuable tool to study biodiversity and to develop more efficient control strategies for biologic processes.

Comparison of bacterial quantities in left and right colon biopsies and faeces

AIM:To compare quantities of predominant and pathogenic bacteria in mucosal and faecal samples.METHODS:Twenty patients undergoing diagnostic colonoscopy with endoscopically and histologically normal mucosa were recruited to the study,14 subjects of which also supplied faecal(F) samples between 15 d to 105 d post colonoscopy.Mucosal biopsies were taken from each subject from the midportion of the ascending colon(right side samples,RM) and the sigmoid(left side samples,LM).Predominant intestinal and mucosal bacteria including clostridial 16S rRNA gene clusters Ⅳ and ⅩⅣab,Bacteroidetes,Enterobacteriaceae,Bifidobacterium spp.,Akkermansia muciniphila(A.muciniphila),Veillonella spp.,Collinsella spp.,Faecalibacterium prausnitzii(F.prausnitzii) and putative pathogens such asEscherichia coli(E.coli),Clostridium difficile(C.difficile),Helicobacter pylori(H.pylori) and Staphylococcus aureus(S.aureus) were analysed by quantitative polymerase chain reaction(qPCR).Host DNA was quantified from the mucosal samples with human glyceraldehyde 3-phosphate dehydrogenase gene targeting qPCR.Paired t tests and the Pearson correlation were applied for statistical analysis.RESULTS:The most prominent bacterial groups were clostridial groups Ⅳ and ⅩⅣa+b andBacteroidetes and bacterial species F.prausnitzii in both sample types.H.pylori and S.aureus were not detected and C.difficile was detected in only one mucosal sample and three faecal samples.E.coli was detected in less than half of the mucosal samples at both sites,but was present in all faecal samples.All detected bacteria,except Enterobacteriaceae,were present at higher levels in the faeces than in the mucosa,but the different locations in the colon presented comparable quantities(RM,LM and F followed byP 1 for RMvs F,P 2 for LMvs F andP 3 for RM vs LM:4.17 ± 0.60 log 10 /g,4.16 ± 0.56 log 10 /g,5.88 ± 1.92 log 10 /g,P 1 = 0.011,P 2 = 0.0069,P 3 = 0.9778 forA.muciniphila;6.25 ± 1.3 log 10 /g,6.09 ± 0.81 log 10 /g,8.84 ± 1.38 log 10 /g,P 1 < 0.0001,P 2 = 0.0002,P 3 = 0.6893 forBacteroidetes;5.27 ± 1.68 log 10 /g,5.38 ± 2.06 log 10 /g,8.20 ± 1.14 log 10 /g,P 1 < 0.0001,P 2 ≤ 0.0001,P 3 = 0.7535 forBifidobacterium spp.;6.44 ± 1.15 log 10 /g,6.07 ±1.45 log 10 /g,9.74 ±1.13 log 10 /g,P 1 < 0.0001,P 2 ≤ 0.0001,P 3 = 0.637 forClostridium cluster Ⅳ;6.65 ± 1.23 log 10 /g,6.57 ± 1.52 log 10 /g,9.13 ± 0.96 log 10 /g,P 1 < 0.0001,P 2 ≤ 0.0001,P 3 = 0.9317 forClostridium cluster ⅩⅣa;4.57 ± 1.44 log10/g,4.63 ± 1.34 log10/g,7.05 ± 2.48 log 10 /g,P 1 = 0.012,P 2 = 0.0357,P 3 = 0.7973 for Collinsella spp.;7.66 ± 1.50 log 10 /g,7.60 ± 1.05 log 10 /g,10.02 ± 2.02 log 10 /g,P 1 ≤ 0.0001,P 2 = 0.0013,P 3 = 0.9919 forF.prausnitzsii;6.17 ± 1.3 log 10 /g,5.85 ± 0.93 log 10 /g,7.25 ± 1.01 log 10 /g,P 1 = 0.0243,P 2 = 0.0319,P 3 = 0.6982 for Veillonella spp.;4.68 ± 1.21 log 10 /g,4.71 ± 0.83 log 10 /g,5.70 ± 2.00 log 10 /g,P 1 = 0.1927,P 2 = 0.0605,P 3 = 0.6476 forEnterobacteriaceae).TheBifidobacterium spp.counts correlated significantly between mucosal sites and mucosal and faecal samples(Pearson correlation coefficients 0.62,P = 0.040 and 0.81,P = 0.005 between the right mucosal sample and faeces and the left mucosal sample and faeces,respectively).CONCLUSION:Non-invasive faecal samples do not reflect bacterial counts on the mucosa at the individual level,except for bifidobacteria often analysed in probiotic intervention studies.

实时荧光定量PCR定量方法研究进展

实时荧光定量PCR以其特异性强、灵敏度高、重复性好、定量准确、速度快、全封闭反应等优点而成为了分子生物学研究中的重要工具,综述了实时荧光定量PCR技术及其定量方法的研究进展,并展望了其应用前景。

实时荧光定量PCR方法检测幼兔粪便双歧杆菌的实验研究

目的:应用实时荧光定量PCR技术对实验幼兔粪便内双歧杆菌进行定量分析．方法:依据双歧杆菌16S rDNA序列设计属特异性引物,以常规PCR产物经克隆后的质粒 DNA为标准品,经光谱定量、梯度稀释后制备标准曲线．抽提正常对照组和双歧杆菌喂饲组幼兔粪便内的细菌基因组DNA,用实时荧光定量PCR技术定量分析样品中双歧杆菌数量．结果:两组幼兔粪便内双歧杆菌测定结果均成阳性,双歧杆菌喂饲组0．05 g湿粪内菌量的对数值较对照组显著升高(6．37±0．58 vs 5．18 ±0．98,P=0．004)．结论:实时荧光定量PCR方法可正确定量实验兔粪便内双歧杆菌数量．

耐氟康唑光滑念珠菌耐药机制研究

目的探讨ERG11、CDR1和CDR2基因差异表达在耐氟康唑光滑念珠菌耐药性形成中的作用。方法采用实时荧光定量逆转录聚合酶链反应(PCR)对临床分离的耐氟康唑药物株、剂量依赖性敏感株和敏感株共22株光滑念珠菌的ERG11、CDR1和CDR2基因表达的mRNA进行相对定量,以2-△△Ct表示试验组目的基因的表达相对于对照组的变化倍数。所有数据采用R(2.15.2)软件进行统计学分析。结果耐药株及剂量依赖性敏感株CDR1、CDR2以及ERG11基因的mRNA表达量均高于敏感株(P<0.05),且随着对氟康唑耐药程度增加而增加。结论 CDR1、CDR2及ERG11基因表达上调是光滑念珠菌临床分离株对氟康唑耐药的主要分子机制。

转基因油菜TOPAS 19/2质粒分子多家协同实验及不确定度评定

质粒分子是转基因产品核酸定量检测的一类新型标准物质,具有易制备、周期短、成本低等特点。采用实时荧光定量PCR技术,并协同7家实验室对转基因油菜TOPAS 19/2质粒分子进行了基因组的可替代性研究、协同实验研究及不确定度评定。T检验表明,质粒和基因组所产生的内源和外源基因标准曲线的斜率和线性相关系数没有显著性差异。对多家定值的数据进行了统计分析得出,TOPAS19/2质粒分子的量值结果为0.910,扩展标准不确定度(K=2)为0.013。

非小细胞肺癌中E-cadherin基因的表达及意义

目的探讨E-cadherin基因在人非小细胞肺癌组织(NSCLC)中的表达及其意义。方法采用实时荧光定量PCR(Q-PCR)方法检测41例NSCLC组织、9例癌旁组织、9例良性病变肺组织中E-cadherin mRNA表达的相对水平,分析其表达与临床、组织病理学特征的关系。结果 E-cadherin mRNA在NSCLC组织表达水平为(9.97±4.25),低于癌旁组织的(11.77±1.91)及良性疾病组织的(23.11±3.52),差异有统计学意义(P<0.01)。在NSCLC组织中E-cadherin mRNA的表达与淋巴结转移有关(P<0.01),与患者年龄、性别、吸烟史、病理类型、分化程度及临床分期无关(P>0.05)。结论 E-cadherin mRNA表达下调与非小细胞肺癌的浸润和转移可能呈负相关,是评价NSCLC进展的一个潜在指标。

多通道实时荧光定量PCR检测HPV DNA结果分析

目的探讨多通道实时荧光定量PCR检测HPVDNA的效果，并应用于日常检测工作。方法对临床1100例宫颈分泌物标本采用多通道实时荧光定量PCR仪进行8种高危HPVDNA分型及定量检测。8种高危HPV型别为主要高危型HPV16、18、45、31和次要高危型HPV33、52、58、67。结果在1100例标本中排除了14例B球蛋白为阴性的标本，剩余1086例标本总体的内标平均值为3．71×10^6IU／ml。随机重复性试验和对每个型别的各浓度标本进行的重复性试验每次扩增均为阳性，型别符合率为100％。共检测出阳性标本287例，HPV16、HPV18／45、HPV31、次要高危型和合并感染各有46、17、14、146和64例，分别占总阳性标本的16％、6％、5％、51％和22％。所有标本绝对定量值的分布近似于正态分布。结论多通道荧光定量PCR检测HPVDNA灵敏度高、复性好，可用于临床HPV感染的筛查与宫颈病变程度预测以及患者术后疗效观察。

炎症性肠病患者胸腺近期输出功能变化

目的:研究炎症性肠病(IBD)患者外周血T细胞受体删除DNA环(TRECs)的含量,了解IBD患者胸腺近期输出功能变化,探讨其在IBD发病中的意义。方法:采用实时荧光定量聚合酶链反应(realtime PCR)检测20名健康人、15例活动期克罗恩病(CD)患者和22例活动期溃疡性结肠炎(UC)患者外周血T细胞中TRECs的含量。结果:TRECs含量CD患者13.48±10.59、UC患者14.67±11.12,各组患者每1000个外周血T细胞中TRECs含量均明显高于健康组8.32±7.02(P均<0.05)。结论:IBD患者幼稚T细胞的含量显著高于正常人,提示IBD患者胸腺近期输出功能在炎症活动期明显增强。

PCR技术与植物病理学的结合

本文综述了聚合酶链式反应（ＰＣＲ）在植物病原物检测、病原物定量、病菌生理小种鉴定以及其它植物病理学领域的应用。

DNA-PK/AKT/GSK3β通路与结肠癌细胞的放射抗拒性

目的探索结肠癌细胞株SW480在长期分割放疗下获得放射抗拒性的可能机制。方法经不同剂量0 Gy、2 Gy、5 Gy、10 Gy单次X射线照射后,以RT-PCR法检测结肠癌亲本细胞SW480和放射抗拒性细胞SW480-R中CCND1mRNA的表达;Western blot法检测DNA-PK/AKT/GSK3β通路中两种细胞株cyclin D1、CDK4、Rb、p-Rb-Ser795、AKT、p-AKT-Ser473、GSK3β、p-GSK3β-Ser9、DNA-PKcs、p-DNA-PKcs蛋白的表达。结果经单次X射线照射0 Gy、2 Gy、5 Gy、10 Gy后,RT-PCR法检测显示SW480-R细胞中CCND1 mRNA的表达明显低于SW480的表达(P<0.05),其相对表达水平分别为0.31±0.02、0.32±0.03、0.34±0.05、0.44±0.04;Western blot法检测显示SW480和SW480-R中的cyclin D1、CDK4、Rb、p-Rb-Ser795、AKT、p-AKT-Ser473、p-GSK3β-Ser9、DNA-PKcs及p-DNA-PKcs蛋白的表达含量在两种细胞中显著不同,SW480-R的蛋白表达明显高于SW480(P<0.05),而GSK3β蛋白的表达含量SW480-R却低于SW480(P<0.05)。结论经过长期分割放疗的结肠癌细胞获得的放射抗拒性可能与激活DNA-PK/AKT/GSK3β通路中cyclin D1蛋白过表达介导的DNA损伤反应(DDR)的改变有关。

Expression of matrix metalloproteinases 2 and 9 in human gastric cancer and superficial gastritis

AIM:To assess expression of matrix metalloproteinases 2(MMP2)and MMP9 in gastric cancer,superficial gastritis and normal mucosa,and to measure metalloproteinase activity.METHODS:MMP2 and MMP9 mRNA expression was determined by quantitative real-time polymerase chain reaction.Normalization was carried out using three different factors.Proteins were analyzed by quantitative gelatin zymography(qGZ).RESULTS:18S ribosomal RNA(18SRNA)was very highly expressed,while hypoxanthine ribosyltransferase-1(HPRT-1)was moderately expressed.MMP2 was highly expressed,while MMP9 was not detected or lowly expressed in normal tissues,moderately or highly expressed in gastritis and highly expressed in cancer.Relative expression of 18SRNA and HPRT-1 showed no significant differences.Significant differences in MMP2 and MMP9 were found between cancer and normal tissue,but not between gastritis and normal tissue.Absolute quantification of MMP9 echoed this pattern,but differential expression of MMP2 proved conflictive.Analysis by qGZ indicated significant differences between cancer and normal tissue in MMP-2,total MMP-9,250 and 110 kDa bands.CONCLUSION:MMP9 expression is enhanced in gastric cancer compared to normal mucosa;interpretation of differential expression of MMP2 is difficult to establish.