α1-acid glycoprotein (AGP):: a possible carrier of sialyl lewis X (slewis X) antigen in colorectal carcinoma
α1-acid glycoprotein (AGP):: a possible carrier of sialyl lewis X (slewis X) antigen in colorectal carcinoma
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DOI：
10.14670/hh-20.91
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发表时间：
2005-01-01
影响因子：
2
通讯作者：
Segal-Eiras, A
中科院分区：
文献类型：
--
作者：
Croce, MV;Sálice, VC;Segal-Eiras, A
目的：1-检测结直肠恶性、良性和正常样品中的α-酸性糖蛋白（AGP）和唾液酸刘易斯x（sLex）; 2-从结直肠癌中分离AGP; 3-研究其与抗sLex单克隆抗体（MAb）的免疫反应性。材料与方法：收集88例大肠癌、22例大肠腺瘤和23例正常人的组织和血清标本。AGP和sLex的表达通过免疫组织化学（IHC）进行了研究;分离方法：用硫酸铵沉淀AGP，并用抗AGP单克隆抗体进行免疫沉淀。通过蛋白A-Sepharose CL-4 B亲和层析分离形成的免疫复合物，并进一步洗脱;通过SDS-PAGE和Western-blot分析级分。采用主成分分析法进行统计学分析。结果：用抗AGP单克隆抗体和sLex单克隆抗体对恶性肿瘤组织进行Western印迹，在45 kD左右出现一条带。免疫组化显示，AGP在70%的大肠癌、50%的良性大肠癌和35%的正常大肠组织中表达。SLex在31%的恶性肿瘤、41%的良性肿瘤和1例正常组织中检出。恶性肿瘤标本的AGP反应包括整个标本，染色强烈而均匀，而正常和良性标本显示限制性反应。在癌症中，sLex表达包括在膜，细胞碎片和一些细胞质病灶中的强烈反应性，而正常和良性样品偶尔染色。AGP和sLex表达之间存在统计学显著正相关。通过放射免疫扩散测定血清AGP水平，并与组织表达进行统计学比较分析，未显示两个参数之间的相关性。结论：AGP可能是大肠癌sLex的携带者。
Objectives: 1- to detect alpha-acid glycoprotein (AGP) and sialyl Lewis x (sLex) in colorectal malignant, benign and normal samples; 2- to isolate AGP from colorectal cancer and 3- to study its immunoreactivity with an anti-sLex monoclonal antibody (MAb). Materials and methods: tissue and serum samples from 88 patients with colorectal cancer, 22 adenomas and 23 normal were included. Expression of AGP and sLex was studied by immunohistochemistry (IHC); isolation approach: AGP was precipitated with ammonium sulphate and immunoprecipitated with anti-AGP MAb. The immune complex formed was isolated by protein A-Sepharose CL-4B affinity chromatography and further eluted; fractions were analysed by SDS-PAGE and Western-blot. Statistical analysis was performed by means of Principal Component Analysis. Results: by Western blot employing anti-AGP MAb and sLex MAbs, isolated fractions from malignant samples showed a band at about 45kD. IHC revealed that AGP was expressed in 70% of colorectal carcinoma samples, 50% of benign and 35% of normals. SLex was detected in 31% of malignant samples, 41% of benign and in one normal sample. In malignant samples, AGP reaction comprised the whole specimen with a strong and homogeneous staining while normal and benign samples showed a restricted reaction. In cancer, sLex expression consisted in an intense reactivity in membrane, cellular debris and some cytoplasmic foci while normal and benign samples were occasionally stained. A statistically significant positive correlation was found between AGP and sLex expression. Serum AGP levels were measured by radial immunodiffusion and statistical comparative analysis with tissue expression did not show a correlation between both parameters. Conclusion: AGP may constitute a carrier of sLex in colorectal cancer.