Liu Caiyun, Guo Jianping, Qu Like, Bing Dong, Meng Lin, Wu Jian, Shou Chengchao
The Key Laboratory of Ministry of Education for Cancer Research and its Application, Department of Biochemistry & Molecular Biology, Peking University School of Oncology, Beijing Cancer Hospital & Institute, Haidian District, Beijing 100036, China.
Cancer Lett. 2008 Sep 28;269(1):148-58. doi: 10.1016/j.canlet.2008.04.037. Epub 2008 Jun 30.
Overexpressions of synuclein-gamma (SNCG) in different cancers display stage-specific patterns. At present, appropriate anti-SNCG monoclonal antibodies (mAbs) with high specificity and affinity are unavailable for different immunoassays in clinical applications. In this study, we generated 10 mAbs against endogenous SNCG and evaluated SNCG levels in several colorectal cancer cell lines, serum samples and tumor tissues from colorectal cancer (CRC) patients. Elevated SNCG levels in cancer cell lines evaluated by a novel sandwich ELISA were consistent with data obtained from Western blot. Secreted SNCG protein levels in sera from CRC patients could be detected by the sandwich ELISA and were further confirmed by Western blot analysis following SNCG enrichment. Immunohistochemical results showed that SNCG was highly expressed in tumor cells of CRC patients, but was undetectable in the adjacent normal epithelium. Taken together, these novel anti-SNCG mAbs specifically recognized endogenous SNCG and were suitable for measuring SNCG levels in cell lysates, human serum samples, and tumor tissues. Elevated serum SNCG and overexpressed SNCG in tumor tissue from CRC patients suggest SNCG is a potential biomarker for CRC.
γ-突触核蛋白（SNCG）在不同癌症中的过表达呈现出阶段特异性模式。目前，在临床应用的不同免疫分析中，尚无具有高特异性和亲和力的合适抗SNCG单克隆抗体（mAb）。在本研究中，我们制备了10种针对内源性SNCG的mAb，并评估了几种结肠癌细胞系、血清样本以及来自结直肠癌（CRC）患者的肿瘤组织中的SNCG水平。通过一种新型夹心ELISA评估的癌细胞系中升高的SNCG水平与蛋白质印迹法获得的数据一致。夹心ELISA可检测CRC患者血清中分泌的SNCG蛋白水平，并且在SNCG富集后通过蛋白质印迹分析进一步得到证实。免疫组织化学结果显示，SNCG在CRC患者的肿瘤细胞中高表达，但在相邻正常上皮中未检测到。综上所述，这些新型抗SNCG mAb可特异性识别内源性SNCG，适用于测量细胞裂解物、人血清样本和肿瘤组织中的SNCG水平。CRC患者血清SNCG升高以及肿瘤组织中SNCG过表达表明SNCG是CRC的潜在生物标志物。
