飞行时间质谱技术在乳腺癌诊断中的应用

 目的 采用表面增强激光解吸电离飞行时间质谱（SELDI-TOF-MS）技术检测乳腺癌患者血清蛋白质指纹图谱，分析健康人与乳腺癌患者以及乳腺癌患者手术前后特异性标志蛋白变化，探讨血清蛋白质指纹图谱在乳腺癌疗效评价及复发监测中的临床意义。方法 用SELDI-TOF-MS技术检测30例乳腺癌患者（术前和术后第7天）及20名健康人的血清蛋白质指纹图谱，筛选乳腺癌特异性蛋白标志物，结合支持向量机软件建立诊断模型。比较乳腺癌手术前后特异性蛋白的变化。结果 与健康人血清蛋白质谱相比，术前乳腺癌血清中有3个差异蛋白，质荷比为2043、3938的标志分子低表达，质荷比为 5639的标志分子高表达。术后质荷比为2043、3938的标志分子稳定上调，质荷比为 5639的标志分子稳定下调，差异具有统计学意义。以筛选3个特异性蛋白质峰的数据构建的诊断模型经交叉验证，灵敏性和特异性均为100 %。结论 SELDI-TOF-MS检测血清蛋白质组学图谱在乳腺癌的早期诊断、术后病情转归及监测复发等方面具有一定的临床指导意义     

非小细胞肺癌放化疗患者血清蛋白质谱分析的初步研究

目的通过对非小细胞肺癌患者放化疗前后及正常对照组血清蛋白质谱的测定,筛选差异蛋白,观察治疗前后血清蛋白质组谱变化。方法应用SELDI-TOF-MS及CM-10芯片对35例正常对照组、35例治疗前非小细胞肺癌患者及26例放化疗后非小细胞肺癌患者采集的血清样品进行蛋白质指纹图谱测定,并应用BioMarker Wizard 3.01及BioMarker Pattern System 5.01分析软件对测得数据进行处理及建立诊断模型。结果非小细胞肺癌组与正常对照组共检测到251个蛋白质峰,筛选出差异蛋白质峰16个,其中肺癌组8个蛋白质峰表达升高,8个蛋白质峰表达降低。以质荷比(M/Z)为2572.1、2885.8、3870.4、4161.4、5739.7和8164.3的6个蛋白质峰为依据组合构建分类决策树模型,原始判别总准确率为87%,敏感性为91%,特异性为83%;交叉验证总准确率为76%,敏感性为80%,特异性为71%。观察16个差异蛋白质峰的表达在放化疗前后的变化,显示均发生了不同程度的变化,趋向健康对照组,其中质荷比为2572.1、2885.8、4664.8、9228.4和9396.4的5个蛋白质峰在治疗前后发生显著变化。结论SELDI-TOF-MS技术对差异蛋白的筛选及治疗疗效的判定可能有一定的意义,需要进一步研究证明。     

高发区筛查人群食管鳞癌血清蛋白指纹图谱诊断模型的建立及临床价值

目的用表面增强激光解吸离子化飞行时间质谱(SELDI-TOF-MS)分析食管鳞癌患者血清蛋白表达谱的改变,筛选并建立高发区食管癌血清蛋白指纹图诊断模型,探究其临床价值。方法采用CM10蛋白芯片及SELDI-TOF-MS技术,对36例食管癌患者和38例正常对照者的血清进行蛋白指纹图谱检测,支持向量机分析实验数据,建立食管癌诊断模型,采用盲法验证。结果在分子量2000～20000范围内,共检测到31个蛋白质荷比峰,差异有统计学意义(P<0.01)。以4个质荷比峰建立了食管癌诊断模型,并用留一法交叉验证作为评估模型判别效果的方法,其准确率为85.1%,敏感性为86.1%,特异性为84.2%,真阳性率为83.8%。结论由4个质荷比峰构成的诊断模型可以区分食管癌和正常对照,为高发区食管癌的筛查与诊断提供了一条新的途径。     

结肠癌与大肠腺瘤及癌旁正常肠黏膜组织差异表达蛋白的筛选

目的:探讨结肠癌、大肠腺瘤及正常肠黏膜组织中蛋白质组的表达差异及其意义。方法:应用表面增强激光解析离子化飞行时间质谱(SELDI-TOF-MS)技术检测结肠癌、大肠腺瘤及正常肠黏膜组织的蛋白图谱,通过BiomarkerWizard软件分析发现差异蛋白,用蛋白质组学数据库检索出部分差异蛋白。结果:发现16种差异蛋白,其中大肠癌组织质荷比(M/Z)为4 904、7 602、7 705、14 990和15 708的蛋白峰强度显著高于正常组织和大肠腺瘤患者,P<0.01;大肠腺瘤与正常人相比,除在M/Z为4 904的蛋白峰强度差异有统计学意义外(P=0.006),其余差异均无统计学意义,P>0.05;数据库检索结果提示,这些蛋白分别为CEA、p53R2、HCG2020031、Kallikrein-11(hk11)和CD99,其中,CEA为目前临床上常用的肿瘤标志,另外4种差异蛋白质可能具有成为肿瘤新标志潜能。结论:SELDI-TOF-MS技术能很好的显示结肠癌、大肠腺瘤与正常肠黏膜组织间的差异表达蛋白,本研究筛选出的其他4种新差异表达蛋白质有可能为研究结肠癌癌变过程中的生物学行为提供新的分子标志。     

雌激素受体β在不同大肠病变组织中的表达及其临床意义

[目的]探讨雌激素受体β（ERβ）在大肠癌发生发展过程中表达及其临床意义。[方法]收集正常人大肠黏膜、FAP腺瘤、FAP腺瘤癌变、腺瘤、腺瘤癌变和散发性大肠癌标本共162例,应用浙江大学附属第二医院自行研制的ZM-1型组织芯片制备仪制作石蜡组织芯片,行免疫组织化学染色。[结果]散发性大肠癌组ERβ阳性表达率（81.25%）明显高于正常大肠黏膜组（44.44%）（P=0.017）;FAP腺瘤癌变组（47.62%）和腺瘤癌变组（38.89%）的ERβ阳性率分别低于FAP腺瘤组（80.00%）和腺瘤组（80.00%）（P=0.005,P=0.033）;且FAP腺瘤癌变组和腺瘤癌变组的ERβ阳性率低于散发性大肠癌组（P〈0.05）;FAP腺瘤组与腺瘤组的ERβ阳性率却均高于正常大肠黏膜组（P〈0.05）。[结论]ERβ在散发性大肠癌组织中的高表达提示ERβ可能是一个散发性大肠癌临床诊断的鉴别标志。FAP腺瘤和腺瘤癌变过程所涉及的分子机制可能与散发性大肠癌变分子机制不同。     

应用SELDI-TOF-MS技术建立卵巢浆液性乳头状囊腺癌诊断的血浆蛋白质组学模型

目的：通过蛋白质芯片-质谱技术结合生物信息学的支持向量机方法，筛选卵巢浆液性乳头状囊腺癌患者差异表达的蛋白质峰，探讨建立数学逻辑的卵巢浆液性乳头状囊腺癌诊断模型及其意义。方法：采用表面增强激光解离飞行时间质谱（surface-enhanced laser desorption/ionization time of flight mass spectrometry,SELDI-TOF-MS）技术，运用CM10蛋白质芯片（一种弱阳离子芯片）分别检测26例卵巢浆液性乳头状囊腺癌和51例对照组（其中卵巢囊肿12例、子宫肌瘤31例、卵巢良性囊腺瘤8例）的血浆标本，对所得到的质谱数据采用Biomarker Wizard软件分析，初步筛选蛋白质峰，结合生物信息学的支持向量机（support vector machines，SVM）方法建立并测试卵巢浆液性乳头状囊腺癌患者以及对照组的血浆蛋白质谱诊断模型。结果：应用SELDI-TOF-MS在CM10芯片上捕获到的蛋白质，经过Biomarker Wizard软件分析筛选出了卵巢浆液性乳头状囊腺癌患者与对照组的71个差异蛋白质峰（P〈0．01），利用SVM方法再次筛选获得7个蛋白质峰组成卵巢浆液性乳头状囊腺癌的蛋白质谱最优化模型，这7个蛋白质中质荷比（m／z）为4099、4477、4123、4081和3938的表达上调，质荷比（m／z）为8785和13783的表达下降。经三倍交叉验证后用盲法测定，所建模型用于卵巢浆液性乳头状囊腺癌患者与对照组鉴别的敏感度和特异度分别为84．62％和96．08％，阳性预测值为92．21％。结论：蛋白质芯片-质谱技术可以快速、有效地筛选出卵巢浆液性乳头状囊腺癌患者血浆差异蛋白质，结合SVM可建立有效的蛋白质质谱诊断模型，对卵巢癌诊断方法的建立具有潜在意义。     

应用磁珠联合质谱技术建立结直肠癌血清差异蛋白诊断模型

目的 应用磁珠联合质谱技术筛选结直肠癌Ⅰ、Ⅱ期患者差异蛋白质,建立其血清学筛查方法。方法 收集血清样本156例（其中结直肠癌80例,健康志愿者76例）,随机分为建模组和验证组。采用弱阳离子磁珠分离血清小分子蛋白,基质辅助激光解吸离子飞行时间质谱仪建立结直肠癌及健康志愿者血清蛋白谱,Clinprot Tools 2.2软件对建模组血清蛋白谱进行定量分析,建立结直肠癌判别模型,以所获取的判别模型判别验证组样本,评价判别模型的诊断价值。应用ELISA法检测验证组癌胚抗原。结果 对比分析建模组结直肠癌及健康志愿者血清蛋白谱,发现共有44个差异蛋白峰（P<0.05）,其中在结直肠癌中高表达35个,低表达9个,利用其中3个差异峰（质荷比分别为1330.95、2883.96、9294.14）建立诊断模型,交叉验证的准确性为94.87%（74/78）,经独立样本双盲验证,其敏感度为87.50%（35/40）,特异性为89.47%（34/38）,高于CEA。结论 应用磁珠分离和质谱技术建立的诊断模型具有较高的准确性,对提高结直肠癌的筛查具有一定的临床意义。     

SELDI-TOF-MS技术筛选鼻型NK/T细胞淋巴瘤血清分子标志物的研究

目的 本文将SELDI-TOF-MS技术应用于鼻型NK/T细胞淋巴瘤患者与健康人的血清蛋白质图谱的建立,寻找血清差异表达蛋白并建立诊断初步模型,分析可能的肿瘤诊断标志物.方法 采用SELDI质谱技术,将血清蛋白质结合于弱阳离子芯片上,建立30例鼻型NK/T细胞淋巴瘤患者以及58例健康对照人群的血清蛋白质图谱,应用Biomarker Wizard和Biomarker Pattern软件分析2组图谱之间的差异,通过差异峰建立分类树诊断模型,随机选取21例NK/T细胞淋巴瘤和25例健康对照进行盲筛.结果 在鼻型NK/T细胞淋巴瘤和健康对照人群的血清蛋白质峰中有41个峰表达差异有统计学意义(P<0.05),经Biomarker Pattern软件和分类回归树的统计原理筛选出最佳的组合模型,联合其中的2个质荷比为5 641、27 427的差异蛋白峰建立淋巴瘤诊断模型,此分类树模型可正确划分93.10%(27/29)的淋巴瘤患者和96.30%(52/54)的健康人.盲筛验证的敏感性为95.24%(20/21),特异性为100.00%(25/25).结论 SELDI-TOF-MS技术可用于鉴别鼻型NK/T细胞淋巴瘤,其建立的分类树模型有望成为诊断鼻型NK/T细胞淋巴瘤的辅助指标.     

蛋白质芯片技术应用于肝癌诊断的初步研究

 【摘要】　目的　应用表面增强激光解析电离飞行时间质谱（SELDI-TOF-MS）技术和蛋白质芯片从肝癌患者血清中筛选可用于肝癌诊断的标志蛋白质。方法　运用SELDI-TOF-MS技术及CM10蛋白质芯片检测46例原发性肝癌患者和64名健康人血清,获得蛋白质指纹图谱,采用Biomarker Wizard软件选出肝癌患者与健康人血清中的表达差异蛋白质,评价其灵敏度、特异度和诊断效能,确定最佳标志蛋白质。结果　肝癌组与健康对照组血清中有16个蛋白质的表达差异在2倍以上,并且差异有统计学意义（P＜0.05）。其中质荷比为6845.70的蛋白诊断效能最高,其灵敏度为89.1 %（41／46）,特异度87.5 %（56／64）,且该蛋白质与肿瘤大小有相关性（r＝-0.363,P＜0.05）。经数据库搜索该蛋白质很可能是免疫球蛋白重链可变区片段。结论　应用SELDI-TOF-MS技术诊断肝癌,具有灵敏度高,特异性好,快速简便的优点,质荷比为6845.70的蛋白质可能是肝癌患者血清中的特异性标志物。     

应用SELDI-TOF-MS蛋白质芯片技术筛选正常和肝癌小鼠血清差异蛋白

[目的]应用蛋白质芯片及表面增强激光解吸离子化飞行时间质谱（SELDI-TOF-MS）技术筛选正常和肝癌小鼠血清差异蛋白。[方法]采用小鼠肝癌细胞株Hepa1-6建立小鼠肝癌模型．分别于接种肝癌细胞后5d、10d、20d处死小鼠,测量肿瘤体积,分离血清,采用弱阳离子蛋白质芯片CM10及SELDI-TOF—MS技术．对正常和肝癌小鼠血清进行蛋白质谱分析。采用BioMarkerWizard软件分析差异蛋白．并经数据库搜索分子量接近的蛋白。[结果]质谱分析共检测出181个蛋白峰．获得13个差异蛋白．其中6个蛋白在肝癌模型小鼠血清中高表达,随肿瘤体积的增大而逐渐升高．7个蛋白在肝癌模型小鼠血清中低表达。随肿瘤体积的增大而逐渐降低。经蛋白质数据库搜索．有14个蛋白的分子量与这些差异蛋白的分子量最为接近。[结论]检测到的13个差异蛋白质可能是肝癌血清特异性生物标志物。     

应用表面加强激光解吸电离-飞行时间-质谱技术检测结直肠癌肝转移

目的 寻找与结直肠癌肝转移相关的蛋白质,建立结直肠癌肝转移的血清蛋白质指纹图谱诊断预测模型.方法 应用表面加强激光解吸电离-飞行时间-质谱(SELDI-TOF-MS)技术,对36例结直肠癌无肝转移患者和36例结直肠癌伴肝转移患者的术前空腹外周静脉血标本,进行蛋白质指纹图谱测定,运用Biomarker Wizard软件,建立结直肠癌肝转移的诊断预测模型.用44例结直肠癌患者和44例结直肠癌伴肝转移患者,对所建立的诊断预测模型进行盲法验证.结果 比较36例结直肠癌无肝转移患者和36例结直肠癌伴肝转移患者的血清蛋白质,得到10个差异蛋白峰(P<0.05),质荷比分别为2398、2814、4084、4289、4465、6422、6619、11 482、11 649和13 714.若以P<0.01为标准,则有3个蛋白质峰差异有统计学意义,质荷比分别为2398、2814和13714.建立终末节点数为9的诊断预测模型,其敏感性为91.7%,特异性为97.2%.验证结果显示,敏感性为75.0%,特异性为81.8%.结论 运用SELDI-TOF-MS技术所建立的血清蛋白指纹图谱模型,在预测结直肠癌肝转移中具有非常高的敏感性与特异性,可望成为预测诊断工具.     

Serum protein fingerprint of patients with pancreatic cancer by SELDI technology

Objective： To study the serum protein fingerprint of patients with pancreatic cancer and to screen for protein molecules closely related to pancreatic cancer during the onset and progression of the disease using surface-enhanced laser desorption and ionization time of fight mass spectrometry （SELDI-TOF-MS）. Methods： Serum samples from 20 pancreatic cancers, 20 healthy volunteers and 18 patients with other pancreatic diseases. WCX magnetic beans and PBSII-C protein chips reader （Ciphergen Biosystems Ins.） were used. The protein fingerprint expression of all the Serum samples and the resulting profiles between cancer and normal were analyzed with BiomarkerWizard system. Results： Agroup ofproteomic peaks were detected. Four differently expressed potential biomarkers were identified with the relative molecular weights of 5705 Da, 4935 Da, 5318 Da and 3243 Da. Among them, two proteins with m/z5705, 5318Da down-regulated, and two proteins with m/z 4935, 3243 Da were up-regulated in pancreatic cancers. Conclusion： SELDI technology can be used to screen significant proteins of differential expression in the serum of pancreatic cancer patients. These different proteins could be specific biomarkers of the patients with pancreatic cancer in the serum and have the potential value of further investigation.     

Discrimination analysis of mass spectrometry proteomics for cervical cancer detection

To study the serum protein fingerprint of patients with cervical cancer and to screen for protein molecules closely related to cervical cancer during the onset and progression of the disease using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Serum samples from 85 patients with cervical cancer and 80 healthy volunteers. Weak cation exchange (WCX) magnetic beads and PBSII-C protein chips reader (Ciphergen Biosystems Ins.) were used.The protein fingerprint expression of all the serum samples and the resulting profiles between cancer and normal were analyzed with Biomarker Wizard system. A group of proteomic peaks were detected. Three differently expressed potential biomarkers were identified with the relative molecular weights of 3974?Da, 4175?Da, 5906?Da. This diagnostic model can distinguish cervical cancer from healthy controls with a sensitivity of 93.3% and a specificity of 95%. Blind test data indicated a sensitivity of 87.5% and a specificity of 90%. MALDI technology can be used to screen significant proteins of differential expression in the serum of cervical cancer patients. These different proteins could be specific biomarkers of the patients with cervical cancer in the serum and have the potential value of further investigation.     

MB-WCX联合MALDI-TOF MS建立结直肠癌血清诊断模型

 目的 运用弱阳离子磁珠（magnetic beads based weak cation exchange, MB-WCX）联合基质辅助激光解吸离子飞行时间质谱（matrix assisted laser desorption ionization time of flight mass spectrometry, MALDI-TOF MS）建立结直肠癌血清蛋白组学诊断模型。方法 收集我院正常对照（健康体检者）、结直肠癌术前及术后患者血清标本各72例,弱阳离子磁珠分离血清多肽,MALDI-TOF MS建立正常对照、结直肠癌术前及术后患者血清蛋白表达谱,ClinProt Tools 2.0软件分析差异表达峰并建立诊断模型,液相色谱-电喷雾离子化质谱（liquid chromatography-eletronic spray ionization mass/mass, LC-ESIMS/MS）鉴定差异表达蛋白。结果 对比分析正常对照、结直肠癌术前及术后血清蛋白图谱,共发现80个差异表达峰,12个峰差异具有统计学意义（均P<0.01）,与对照组相比,其中9个差异峰在结直肠癌术前的血清蛋白图谱中显示升高,术后显示降低,3个峰在结肠癌术前的血清蛋白图谱中显示降低,术后显示升高。遗传算法（genetic algorithm, GA）模型诊断结直肠癌的敏感度和特异性分别为99.31%和96.49%。GA模型中m/z: 2663.36、m/z: 4793.17和m/z: 5343.48的差异表达峰经鉴定分别为纤维蛋白原α前体亚型1（isoform 1 of Fibrinogen alpha chain precursor, FGA）、组蛋白赖氨酸甲基转移酶SETD7（histone-lysine N-methyltransferase SETD7, SETD7）和黏蛋白5AC（Mucin-5AC precursor, MUC5AC）。结论 血清蛋白质谱模型能够准确区分正常对照与结直肠癌患者,但尚需更进一步研究证实。     

Alteration of O6-methylguanine-DNA methyltransferase in colorectal neoplasms in sporadic and familial adenomatous polyposis patients

DNA repair failure is known to be a critical event during carcinogenesis of colorectal cancers. To investigate whether O(6)-methylguanine-DNA methyltransferase (MGMT) is altered during colorectal carcinogenesis, we performed immunohistochemical staining on 265 sporadic colorectal cancers, 113 sporadic adenomas, 33 familial adenomatous polyposis (FAP) colorectal cancers, and 93 FAP adenomas. Sixty-seven of 265 sporadic colorectal cancer cases and five of 113 sporadic adenoma cases showed loss of MGMT expression (P < 0.001). Among FAP patients, four of 33 cancers and six of 93 adenomas showed loss of MGMT protein expression. When we compared the association between MGMT promoter hypermethylation and protein expression, almost all cases without a methylated allele were positive for the expression of MGMT. In contrast, cases with promoter methylation frequently showed loss of MGMT expression (P < 0.01). Loss of MGMT was correlated with some clinicopathological characteristics, i.e., tumor invasion (P = 0.013) and stage (P = 0.035) in sporadic colorectal cancer, and degree of atypism (P = 0.042) in sporadic adenoma. Our results show that loss of expression of MGMT occurs more frequently in cancer than in adenoma in both sporadic and FAP patients, and that loss of expression of MGMT is associated with hypermethylation of the promoter area of MGMT gene.     

Effect of surface-enhanced laser desorption/ionization time-of-flight mass spectrometry on identifying biomarkers of laryngeal carcinoma

The aim is to study the serum protein fingerprint of patients with laryngeal carcinoma (LC) and to screen for protein molecules closely related to LC during the onset and progression of the disease with surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS). Serum samples from 68 patients with LC and 117 non-cancer control samples (75 healthy volunteers and 42 Vocal fold polyps). Q10 protein chips and PBSII-C protein chips reader (Ciphergen Biosystems Inc.) were used. The protein fingerprint expression of all the Serum samples and the resulting profiles between cancer and non-cancer groups were analyzed with Biomarker Wizard system. A group of proteomic peaks were detected. Three differently expressed potential biomarkers were identified with the relative molecular weights of 5,915, 6,440 and 9,190 Da. Among the three peaks, the one with m/z 6,440 was down-regulated, and the other two peaks with m/z 5,915 and 9,190 were up-regulated in LC. This diagnostic model could distinguish LC patients from controls with a sensitivity of 92.1% and a specificity of 91.9%. Moreover, blind test data showed a sensitivity of 86.7% and a specificity of 89.1%. The data suggested that SELDI technology could be used to screen proteins with altered expression levels in the serum of LC patients. These protein peaks were considered as specific serum biomarkers of LC and have the potential value for further investigation.     

应用SELDI-TOF-MS技术筛选肺腺癌患者血清诊断标志物

目的 探讨肺腺癌患者及正常人血清中蛋白质质谱的不同,筛选出肺腺癌血清诊断标志物.方法 用WCX2蛋白芯片结合表面增强激光解吸电离飞行时间质谱(SELDI-TOF-MS)技术,检测24例肺腺癌和10例正常人血清蛋白质谱,筛选出差异表达蛋白质.结果 本实验共检测到86个有效的蛋白质波峰,其中m/z位于分子质量2000～10 000的波峰有78个.筛选出m/z分子质量为8129.55,2022.18,3271.91,3933.44,3504.49,3811.71的6个血清肿瘤标志物.结论 SELDI-TOF-MS技术是寻找肺腺癌血清诊断标志物的有效工具.利用蛋白组学和生物信息学及相关技术,将有利于建立新的疾病诊断模式--蛋白质指纹图谱.     

K-ras gene mutation in colorectal adenomas and carcinomas from familial adenomatous polyposis patients.

Colorectal adenomas and carcinomas from familial adenomatous polyposis (FAP) patients were screened for the presence of K-ras gene mutations at codon 12 using an in vitro amplification step (polymerase chain reaction) followed by dot blot analysis using oligonucleotide probes specific for different mutations at codon 12. We examined 28 colorectal adenomas and two colorectal carcinomas from 12 FAP patients and observed a mutation at codon 12 in seven adenomas and in both carcinomas. The frequency of K-ras gene mutations in colorectal tumours from FAP patients is similar to those in cases of sporadic adenomas and sporadic colorectal carcinomas indicating that the mechanisms involved in their development may be similar.     

应用液体蛋白芯片飞行时间质谱系统研究胃癌的血清蛋白差异表达谱*

目的:应用液体蛋白芯片飞行时间质谱系统分析胃癌患者血清蛋白质表达谱,寻找具有潜在诊断意义的血清标志物。方法:收集血清样本62 例,其中正常对照组（N 组）16 例,胃癌组（T 组）28 例,验证组18 例。经WCX磁珠纯化、MALDI-TOF-MS 及ClinproTools生物信息学方法研究其血清蛋白表达谱,并筛选出差异蛋白质峰,运用数据挖掘算法,构建胃癌的血清蛋白诊断模型,并在验证组中验证其准确性。结果:1）通过对比胃癌组和正常组的血清蛋白质谱图,分析得到 25 个具有显著差异的蛋白质峰,其中差异最显著的前两位质核比分别为 5 248.49 m/z和5 754.25 m/z,其灵敏度分别为 84 .61 %和73 .07 %,特异性分别为 100%和93 .75 %,能很好地区分胃癌组和正常组。2）通过 ANN 的数据挖掘的方法,在具有显著差别的 25 个蛋白质峰中,筛选了组合能力最强的6 个蛋白峰（分别为4 268.05 m/z、5 636.53 m/z、5 248.49 m/z、2 933.15 m/z、1 450.13 m/z和1 349.4m/z）,建立了胃恶性肿瘤的诊断模型,其识别率为100%,预测能力为 90 .59 %,准确性为 100%。将已知信息的验证组 18 例分别代入已建立的模型,特异性和灵敏性分别为75 %和100%。结论:液体蛋白芯片飞行时间质谱系统作为研究蛋白表达谱的工具,能够用于筛选潜在的胃恶性肿瘤的血清标志物,利用其优点并结合统计学的方法,建立血清学胃癌的诊断模型,能为胃恶性肿瘤的筛查提供帮助。      

Familial adenomatous polyposis is associated with a marked decrease in alkaline sphingomyelinase activity: a key factor to the unrestrained cell proliferation?

The hydrolysis of sphingomyelin generates key molecules regulating cell growth and inducing apoptosis. Data from animal cancer models support an inhibitory role for this pathway in the malignant transformation of the colonic mucosa. In the intestinal tract, a sphingomyelinase with an optimum alkaline pH has been identified. We recently found that the activity of alkaline sphingomyelinase is significantly decreased in colorectal adenocarcinomas, indicating a potential anticarcinogenic role of this enzyme. To further examine whether the reduction of sphingomyelinase is present already in the premalignant state of neoplastic transformation, we measured sphingomyelinase activities in patients with familial adenomatous polyposis (FAP) and in sporadic colorectal tubulovillous adenomas. Tissue samples were taken from adenomas and surrounding macroscopically normal mucosa from 11 FAP patients operated with ileorectal anastomosis, from three FAP patients with intact colon, from 13 patients with sporadic colorectal adenomas and from 12 controls. Activities of acid, neutral and alkaline sphingomyelinase were measured together with alkaline phosphatase. In FAP adenoma tissue, alkaline sphingomyelinase activity was reduced by 90% compared to controls (P < 0.0001), acid sphingomyelinase by 66% (P < 0.01) and neutral sphingomyelinase by 54% (P < 0.05). Similar reductions were found in the surrounding mucosa. In sporadic adenoma tissue, only alkaline sphingomyelinase was reduced significantly, by 57% (P < 0.05). Alkaline phosphatase was not changed in FAP adenomas, but decreased in the sporadic adenomas. We conclude that the markedly reduced levels of alkaline sphingomyelinase activities in FAP adenomas and in the surrounding mucosa may be a pathogenic factor that can lead to unrestrained cell proliferation and neoplastic transformation.