Identification and distribution of thioredoxin-like 2 as the antigen for the monoclonal antibody MC3 specific to colorectal cancer
Identification and distribution of thioredoxin-like 2 as the antigen for the monoclonal antibody MC3 specific to colorectal cancer
复制标题
作为结直肠癌特异性单克隆抗体 MC3 抗原的硫氧还蛋白样 2 的鉴定和分布
DOI：
10.1002/pmic.200700770
复制
发表时间：
2008-06-01
期刊：
影响因子：
3.4
通讯作者：
Fan, Daiming
中科院分区：
文献类型：
--
作者：
Lu, Yuanyuan;Wang, Xin;Fan, Daiming
MC3是我们实验室前期制备的结直肠癌（colorectal cancer， CRC）特异性单抗，具有较高的检测CRC的敏感性和特异性。然而，由于技术限制，MC3的靶抗原尚未确定。本研究通过免疫细胞化学和免疫组织化学揭示了MC3抗原（MC3- ag）在结肠癌细胞系和结直肠癌组织中的表达规律。Western blotting分析显示，MC3抗体可重复识别人结肠癌细胞株SW480和HT-29总细胞裂解物中两个相似的30 kDa蛋白。利用蛋白质组学方法，我们确定了两个MC3免疫反应点是硫氧还蛋白样2 （Txl-2）蛋白的两个亚型。进一步配对免疫染色显示，Txl-2与MC3抗体检测的表达谱相同。Western blotting也显示两种抗体能检测到相同的两条条带，进一步证实Txl-2是MC3抗体的抗原。此外，组织阵列揭示了Txl-2在各种正常和癌组织中的表达模式。进一步分析发现，与癌旁组织和癌旁正常组织相比，18例结直肠癌组织中Txl-2 mRNA表达升高。
MC3 is a colorectal cancer (CRC)-specific mAb previously prepared in our laboratory that can detect CRC with high sensitivity and specificity. However, the target antigen for MC3 had not been identified due to technological limitations. in the present study, immunocytochemistry and immunohistochemistry revealed the expression patterns of MC3 antigen (MC3-Ag) in colon cancer cell lines and CRC tissues. Western blotting analysis showed that the MC3 antibody reproducibly recognized two similar to 30 kDa proteins in the total cell lysates of human colon carcinoma cell lines SW480 and HT-29. Using a proteomic approach, we identified two MC3 immunoreactive spots as two isoforms of thioredoxin-like 2 (Txl-2) protein. Further paired immunostaining showed that Txl-2 had the same expression profile as probed by the MC3 antibody. Western blotting also showed that both antibodies could detect the same two bands, further verifying that Txl-2 is the antigen of MC3 antibody. Additionally, tissue arrays revealed the expression patterns of Txl-2 in various normal and cancer tissues. Further analysis showed that Txl-2 mRNA was elevated in 18 cases of CRC tissues compared to paracancerous tissues and adjacent normal tissues.