Human kallikrein 10 ELISA development and validation in breast cancer sera

BACKGROUND: Human kallikrein 10 (hK10) is a putative secreted serine protease belonging to the same gene family as prostate specific antigen (hK3; PSA). There is significant interest in measuring hK10 which may act as a tumor suppressor in some cancers. We have developed an ELISA for hK10 and determined its analytical and clinical performance in normal and breast cancer sera. METHODS: The assay used a previously described pair of monoclonal anti-hK10 antibodies and recombinant hK10 protein. Serum hK10 was detected quantitatively in a 2-step sandwich ELISA with colorimetric detection. The assay was analytically validated and used to determine serum levels of hK10 in a set of breast cancer, benign breast disease and normal samples. RESULTS: The assay covered a linear range of 0.2 to 15 ng/mL and had a detection limit of 0.08 ng/mL. The within-run and between-run imprecision was <9%. The average spike and dilution linearity recoveries were 96 and 103% respectively. Mean hK10 concentration in normal female sera was 0.79+/-0.26 ng/mL. Concentrations were not age related and were not significantly different from benign fibrocystic disease or breast cancer. However, in a subset of breast cancer patients with both early and late stage disease, serum hK10 levels were elevated, at >1.55 ng/mL, above all normal female and benign disease samples. CONCLUSIONS: We report in detail the analytical performance of a colorimetric hK10 ELISA validated in human serum and report for the first time the hK10 serum concentration in benign and breast cancer samples.     

Mammaglobin: a candidate diagnostic marker for breast cancer

Mammaglobin, known for its mammary tissue specificity, has been discussed as a promising diagnostic marker in breast cancer for almost 10 years. In particular, the application of mammaglobin RT-PCR to detect disseminated breast cancer cells has been reported. More than 25 publications evaluate the detection of mammaglobin mRNA in lymph node, blood, and bone marrow specimens of breast cancer patients. Recently, structural details about the mammaglobin complex have been discovered, and these findings can be implemented to optimize detection of the secreted protein. This review summarizes the findings of almost 50 published studies and the current knowledge about the diagnostic utility of mammaglobin.     

乳腺癌外周血SBEM和hMAM联合检测的临床意义

目的 探讨乳腺癌患者外周血乳腺小粘蛋白(SBEM)及人乳腺珠蛋白(hMAM)的表达及临床意义.方法 采用酶联免疫吸附试验(ELISA)定量检测68例乳腺癌患者及20例乳腺纤维腺瘤患者及20例健康志愿者术前血清SBEM和hMAM的水平.结果 乳腺癌组术前血清SBEM和hMAM水平均高于纤维腺瘤组和健康对照组(P均<0.01).有淋巴结转移的乳腺癌患者血清中SBEM和hMAM水平明显高于无淋巴结转移者,差异均有统计学意义(P均<0.05).Ⅲ期患者血清SBEM和hMAM水平显著高于Ⅰ+Ⅱ期患者(P均小于0.01).结论 SBEM及hMAM特异性表达于乳腺癌外周血,有可能作为检测乳腺癌外周血微转移的标志物,有望成为判断乳腺癌患者病情发展和预后的新指标.     

Quantitative RT-PCR luminometric hybridization assay with an RNA internal standard for cytokeratin-19 mRNA in peripheral blood of patients with breast cancer

Objectives: To develop a highly sensitive quantitative RT-PCR hybridization assay for the determination of CK-19 mRNA in peripheral blood of patients with breast cancer.

Patients and methods: Quantification of CK-19 mRNA was based on the coamplification of CK-19 mRNA with a recombinant CK-19 RNA internal standard (CK-19 RNA-IS) through RT-PCR. The biotinylated amplification products were immobilized on steptavidin coated wells, hybridized with digoxigenin labeled probes and determined through an antidigoxigenin antibody conjugated to alkaline phosphatase by luminometric detection. The developed luminometric hybridization assay was validated with samples containing total RNA of known amounts from CK-19 expressing cells (MCF-7) in the presence of 1 μg total RNA isolated from peripheral blood mononuclear cells (PBMC) of healthy controls and a constant amount of CK-19 RNA-IS. The method was applied for the quantitative determination of CK-19 mRNA in the peripheral blood of 26 healthy volunteers, 14 patients with stage IV breast cancer and 37 patients with stage I/II breast cancer before chemotherapy.

Results: Luminescence ratios for CK-19 mRNA and CK-19 RNA-IS were linearly related to the number of MCF-7 cells within the range of 1 to 2000 cells. The overall reproducibility of the assay (between-run) varied between 8.9% and 13.4%. The method can clearly detect CK-19 mRNA from 1 MCF-7 cell in the presence of 10⁶ normal PBMC and is highly specific as none of the 26 healthy controls tested had detectable CK-19 mRNA levels, while 10 out of 14 (71.4%) and 9 out of 37 (24.3%) patients with stage IV and stage I/II breast cancer, respectively, were tested positive.

Conclusion: The developed quantitative RT-PCR hybridization assay for CK-19 is reproducible, highly sensitive and specific, and can be used for a large-scale prospective evaluation of clinical samples.     

丙型肝炎病毒核心抗原检测试剂盒的临床应用评价

目的采用酶联免疫吸附试验（ELISA）检测丙型肝炎病毒核心抗原（HCVcAg）。方法对苏州市吴中人民医院2011年2月至2012年2月的2 523份输血、手术前住院患者血清标本进行抗-HCV初、复检检测。将初、复检均阳性的其中10份、仅初检阳性的15份和仅复检阳性的17份血清标本分别采用ELISA检测HCVcAg和采用RT聚合酶链反应（RT-PCR）检测HCV。结果 ELISA检测HCVcAg阳性结果为4份（40%）。32份仅初检或复检抗-HCV阳性标本采用ELISA检测HCVcAg阳性6份,阳性率为18.75%。采用RT-PCR荧光定量检测HCV 10份初、复检抗-HCV均阳性的血清标本结果均为阳性,32份仅初检或复检抗-HCV阳性标本采用RT-PCR荧光定量检测HCV阳性5份,阳性率为15.63%。结论 HCVcAg的敏感性与RT-PCR荧光定量检测HCV类似,能对HCV的感染作出早期诊断。     

Detection of autoantibodies to survivin and livin in sera from patients with breast cancer

BACKGROUND: Survivin and livin are highly expressed in cancer cells and transformed cells, but show little or no expression in normal differentiated tissues. Human antibody responses to tumor-associated antigens have been detected, but little is known about the response to survivin and livin in breast cancer patients. METHODS: We examined the prevalence of anti-survivin and livin antibodies in breast cancer patients with a specific enzyme-linked immunosorbent assay (ELISA) using recombinant protein. RESULTS: Using a cutoff value for positivity determined as the mean absorbance +2SD for healthy control samples, sera from 11 of 46 breast cancer patients (23.9%) were positive by the ELISA using recombinant survivin protein. Of 46 samples from the same breast cancer patients, 15 (32.6%) were positive for anti-livin antibodies. In addition, 24 (52.2%) were positive for 1 or both ELISAs using the respective proteins. Intensity of anti-livin antibody responses did not correlate with intensity of anti-survivin responses. CONCLUSIONS: Anti-livin antibodies were detected in sera from breast cancer patients by an anti-livin ELISA using full-length recombinant livin protein. Like survivin, livin may act as a major cancer antigen in breast cancer patients.     

乳腺珠蛋白基因在大肠杆菌中的诱导表达及纯化研究

目的 克隆乳腺珠蛋白（human mammaglobin,hMAM）编码全长cDNA,原核表达并纯化蛋白产物,为后期研制乳腺癌早期诊断试剂盒奠定基础,从而为早期发现乳腺癌提供科学的监测方法。方法 自乳腺癌组织提取总RNA,通过RT-PCR克隆hMAMcDNA,构建pQFA0-hMAM表达质粒,在大肠杆菌M15中表达,利用镍-亚硝胺乙酸组氨酸（Ni-NTA-His）亲和层析法对重组蛋白进行纯化。结果 表达的融合蛋白以不溶性包涵体形式存在,纯化后得到纯度为97％的目的蛋白。结论 成功地纯化出hMAM重组蛋白。     

HER-2 protein concentrations in breast cancer cells increase before immunohistochemical and fluorescence in situ hybridization analysis turn positive.

BACKGROUND: The level of HER-2/neu in breast cancer cells is normally measured by immunohistochemistry (IHC) and/or fluorescence in situ hybridization (FISH). It determines whether patients should be treated with trastuzumab (Herceptin). In this study, HER-2 protein in breast cancer tissue was measured using a quantitative method. METHODS: Tissue samples of malignant and adjacent benign breast tissue were collected from 118 consecutive women admitted for surgical treatment of breast cancer. The HER-2 protein concentration was determined by 2 HER-2 assays: ELISA and the Bayer ADVIA Centaur assay. Paraffin-embedded tissue sections of the corresponding tumors were analyzed by IHC and FISH. RESULTS: Increased HER-2 concentrations in cancer tissue were found compared to autologous reference tissue (p<0.0001, Wilcoxon test) and normal breast tissue (p<0.0001, Mann-Whitney test). Good concordance rates were observed between the methods: 95.8% for IHC and FISH; 86.4% for IHC and ELISA; and 87.3% for FISH and ELISA. The HER-2 positivity rate was determined to 26.3% by ELISA, 12.7% by IHC and 16.9% by FISH. No correlation was found with tumor grade, axillary node status or serum HER-2 levels. CONCLUSIONS: Detection of HER-2 overexpression by measuring HER-2 in tissue extracts by ELISA seems to be more sensitive than IHC and FISH. This suggests that some patients deprived of Herceptin treatment may benefit from this treatment and may also explain the conversion phenomenon from HER-2-negative to HER-2-positive observed in relapse and metastatic disease.     

检测血清p185糖链凝集素酶联免疫吸附试验的建立及初步应用

目的建立检测血清p185糖链的凝集素酶联免疫吸附试验(ELISA),并初步应用于乳腺癌的临床诊断。方法用改良过碘酸钠氧化法制备c-erbB-2单克隆抗体-辣根过氧化物酶结合物(A18-HRP),经棋盘滴定确认A18-HRP、生物素化麦胚凝集素(B io-WGA)及链霉亲和素(SA)的最适浓度(或稀释度),建立了检测p185糖链的凝集素ELISA,用所建立的方法检测血清p185糖链,免疫组化方法检测组织p185蛋白表达。结果乳腺癌患者血清p185糖链水平明显高于乳腺增生和正常对照(P<0.01),免疫组化阳性和阴性的乳腺癌患者血清p185糖链水平均高于乳腺增生和正常对照(P<0.01),乳腺增生患者血清p185糖链与正常对照相比差异无显著性(P>0.05)。血清p185糖链诊断乳腺癌的敏感度为86.7%,特异度为94.6%,准确度为91.9%。结论本实验建立的凝集素ELISA检测血清p185糖链诊断乳腺癌与病理学诊断符合率高,临床具有实用价值。     

An indirect sandwich ELISA for LP(a) in serum and dried blood spots.

We have established a reproducible and inexpensive indirect sandwich ELISA for Lp(a) quantitation in both serum and dried blood spot samples. All reagents used in the assay are available commercially. The intra-assay CVs were 3.8 +/- 0.9% for serum and 4.5 +/- 1.7% for dried blood spots on filter paper. The inter-assay CVs were 6.3 +/- 2.3% and 4.5 +/- 0.1% for serum and dried blood spot, respectively. Lp(a) concentrations measured by the ELISA and a commercial RIA were highly correlated (r = 0.989, n = 60, P less than 0.001). However concentrations measured by RIA were 34.3% +/- 9.7% higher than those by ELISA. Lp(a) concentrations in serum and in dried blood spots were also highly correlated (r = 0.966, n = 40, P less than 0.001). This indirect ELISA is suitable for assaying large numbers of serum or dried blood spot samples. However, the differences between the concentrations measured by ELISA and RIA stress the need for standardization of Lp(a) measurements.     

丙型肝炎病毒抗体双抗原夹心法酶联免疫试剂的初步临床评价

目的对研制的丙型肝炎病毒抗体（双抗原夹心）酶联免疫检测试剂进行临床评价。方法以克隆表达的HCV多表位嵌合蛋白作为包被抗原,经多表位嵌合蛋白修饰后用于标记抗原,研制HCV双抗原夹心酶联免疫检测试剂;检测血液筛查阴性标本440份,乙肝表面抗原阳性标本90份,HIV抗体阳性标本10份,梅毒螺旋体抗体阳性标本90份及丙型肝炎病毒抗体阳性标本259份。结果对259份HCV抗体阳性标本进行检测时,有3份标本未检出,应用Chiron RIBA确认试剂检测后,结果为阳性。其余标本的检测结果均为阴性。结论采用HCV双抗原夹心酶联免疫检测试剂共检测889份标本,其中只有3份标本结果不一致,总符合率99．7％,敏感性和特异性较好。     

血清乳腺珠蛋白与乳腺癌的相关性及临床意义探讨

目的探讨血清人乳腺珠蛋白(hMAM)水平与乳腺癌早期诊断和癌微转移的相关性及其临床意义。方法应用酶联免疫吸附试验(ELISA)检测68例乳腺癌患者、40例其他癌症患者(前列腺癌、胃癌、卵巢癌、直肠癌各10例)、35例良性乳腺疾病患者以及40名体检正常女性(正常对照组)血清hMAM水平并做比较。将68例乳腺癌患者按临床TNM分期、是否存在雌激素受体(ER)表达、是否有腋窝淋巴结转移以及是否绝经分别分组并做比较。通过受试者工作特征(ROC)曲线确定乳腺癌血清hMAM的Cut-off值。结果血清hMAM的ROC曲线下面积为0.825,即诊断乳腺癌的可信度为82.5%[95%可信区间(CI):72.6%~92.4%];当hMAM的Cutoff值为8.43 ng/mL时,敏感性和特异性分别为76.5%、82.9%。乳腺癌组血清hMAM水平及阳性率明显高于良性乳腺疾病组、其他癌症组和正常对照组(P0.05),而良性乳腺疾病组、其他癌症组和正常对照组之间差异均无统计学意义(P0.05)。Ⅲ和Ⅳ期乳腺癌患者的血清hMAM阳性率(55%、75%)明显高于Ⅰ和Ⅱ期患者(25%、40%,P0.05),但hMAM水平无差异(P0.05)。有腋窝淋巴结转移的乳腺癌患者血清hMAM阳性率(88%)明显高于无转移的患者(30%,P0.05),但hMAM水平无差异(P0.05)。不管乳腺癌患者血清中是否存在ER、原癌基因C-erb-2表达及是否绝经,其hMAM水平及阳性率均无差异(P0.05)。结论 hMAM的表达与乳腺癌临床分期和是否有腋窝淋巴结转移相关;检测乳腺癌高危人群血清hMAM水平有助于提高乳腺癌的早期诊断和癌微转移的早期发现。     

HE4、CAl53联合检测在乳腺癌辅助诊断中的应用

目的研究血清人附睾上皮分泌蛋白4(HE4)、癌抗原153(CAl53)联合检测在乳腺癌辅助诊断中的价值。方法收集46例乳腺癌患者、52例乳腺良性疾病患者以及50名正常对照者血清,采用酶联免疫吸附试验(ELISA)检测血清HE4含量、电化学发光法检测CAl53含量。采用受试者工作特征(ROC)曲线确定HE4和CA153的临界值。分别计算HE4和CA153单项检测和联合检测的敏感性和准确性并作比较。结果乳腺癌组HE4和CAl53水平分别是49.0(41.7～67.4)pmol/L和20.6(13.4～28.7)U/mL,均明显高于乳腺良性疾病组及正常对照组(P<0.01)。经ROC曲线确定HE4和CA153的临界值分别为62.5 pmol/L和21.6 U/mL,乳腺癌HE4、CAl53联合检测的敏感性为63.0%,准确性为82.4%,均高于单项检测。结论联合检测CAl53和HE4可以明显提高乳腺癌诊断的准确性及敏感性。     

乳腺癌组织中原癌基因BMI-1及人表皮生长因子受体-2表达与外周血微转移的关系

目的 观察乳腺癌患者乳腺癌组织中原癌基因BMI-1、人表皮生长因子受体-2(human epidermal growth factor receptor 2,HER-2)阳性表达情况,探讨乳腺癌组织BMI-1、HER-2与外周血微转移的关系.方法 89例乳腺癌患者,均采用实时荧光定量PCR法检测人乳腺珠蛋白mRNA相...     

人组织激肽释放酶6双抗夹心ELISA方法的建立及临床初步应用

目的通过制备的人组织型激肽释放酶6(hK6)单克隆抗体(mAb),建立双抗夹心酶联免疫吸附测定(ELISA)检测方法,并用于胃癌诊断。方法采用该实验室保存的hK6重组蛋白,免疫BALB/c小鼠后通过杂交瘤技术制备特异性的mAb,经鉴定纯化、酶标记后,建立双抗夹心ELISA方法,检测胃癌患者血清中hK6水平,并联合检测血清中的癌胚抗原(CEA)水平,探讨hK6作为胃癌生物标记的可行性。结果成功建立了检测血清中hK6的双抗夹心ELISA方法,并确定该方法包被抗体的最适浓度为5μg/mL,酶标记抗体的最佳稀释比例为1∶2 000。该方法检测各组血清中的hK6水平,与胃溃疡组hK6水平[(3.59±1.02)ng/mL]和健康体检组hK6水平[(3.35±0.67)ng/mL]比较,胃癌组hK6水平[(5.78±1.66)ng/mL]明显高于其他两组,差异有统计学意义(P0.05);而胃溃疡组与健康体检组hK6水平比较,差异无统计学意义(P0.05)。胃癌患者hK6和CEA检测的阳性率分别为69.70%和45.46%,两者联合检测的阳性率为78.79%。结论成功建立了hK6双抗夹心ELISA检测方法;hK6是较好的胃癌血清肿瘤标记物,同时检测hK6与CEA可提高胃癌的检出率,减少漏诊的发生,有助于胃癌的诊断。     

人乳腺癌特异性基因1 mRNA实时荧光定量逆转录-聚合酶链反应检测试剂盒的建立及应用

目的建立人乳腺癌特异性基因1(BCSG1)mRNA实时荧光定量逆转录-聚合酶链反应(RTPCR)检测试剂盒,并评价其在乳腺癌循环肿瘤细胞检测中的应用价值。方法优化试剂盒中各组分的浓度、确定试剂盒的稳定性、灵敏度及特异性,并检测外周血样品中BCSG1 mRNA的表达水平。结果优化了试剂盒中的引物、探针,成功制备了定值标准品,通过设立阴、阳性质控品的方法,解决了试剂盒的特异性、灵敏性、准确性及质量控制等关键技术问题,特异度及准确性均为95%以上,灵敏度为100拷贝/ml(全血)。外周血标本中BCSG1 mRNA的检测结果为,12例临床确诊已转移的乳腺癌患者均为阳性,21例临床未确诊转移的乳腺癌患者中12例为阳性,其余9例为阴性,15例乳腺良性疾病患者、10例正常人均为阴性。结论建立的BCSG1 mRNA实时荧光定量RT-PCR检测试剂盒具有很高的临床应用价值,可用于检测外周血样品中BCSG1mRNA的表达量,检测结果可作为乳腺癌患者诊疗过程中的重要监测指标。