Ye Bin, Cramer Daniel W, Skates Steven J, Gygi Steven P, Pratomo Vanessa, Fu Lanfei, Horick Nora K, Licklider Larry J, Schorge John O, Berkowitz Ross S, Mok Samuel C
Department of Obstetrics & Gynecology, Brigham and Women's Hospital, Dana-Farber Cancer Institute, Dana-Farber Harvard Cancer Center, Boston, MA 02115, USA.
Clin Cancer Res. 2003 Aug 1;9(8):2904-11.
The objective of this study was to identify and characterize new serum biomarkers in ovarian cancer patients using mass spectrometric protein profiling and specific immunological assays.
Serum samples from 80 cancer patients and 91 healthy women were analyzed by surface enhanced laser desorption and ionization-mass spectrometry (MS) profiling. A candidate biomarker was purified by affinity chromatography, and its sequence was determined by liquid chromatography-tandem MS. An antibody was generated from the synthesized peptide for quantitative validation in the cases and controls. CA125 was determined and compared with the same set of specimens.
Using surface enhanced laser desorption and ionization, we found a serum biomarker at approximately 11700 Da, which had peak intensity significantly higher in cases (1.366) compared with controls (0.208, P = 0.002), and subsequently identified this as the alpha chain of haptoglobin. ELISA indicated that Hp-alpha was </=2-fold higher in cancer serum compared with normal, benign tumor, and other gynecological cancers (P < 0.05) and had 64% sensitivity at 90% specificity alone and 91% sensitivity and 95% specificity if combined with CA125.
Haptoglobin-derived alpha subunit is a potential marker for ovarian cancer that is complementary to CA125. MS-based protein profiling is a valuable tool for screening protein markers and useful to detect post-translational modification of tumor-associated proteins or abnormal metabolic products. However, confirmation of protein identity with specific antibodies is crucial for clinical application and functional studies.
本研究的目的是使用质谱蛋白质谱分析和特定免疫测定法来鉴定和表征卵巢癌患者新的血清生物标志物。
采用表面增强激光解吸电离质谱（MS）分析80例癌症患者和91例健康女性的血清样本。通过亲和色谱法纯化候选生物标志物，并通过液相色谱-串联质谱法测定其序列。从合成肽产生抗体，用于病例和对照中的定量验证。测定CA125并与同一组标本进行比较。
使用表面增强激光解吸电离，我们在约11700 Da处发现一种血清生物标志物，其病例组的峰强度（1.366）明显高于对照组（0.208，P = 0.002），随后将其鉴定为触珠蛋白的α链。ELISA表明，与正常、良性肿瘤和其他妇科癌症相比，癌症血清中的触珠蛋白α链升高不超过2倍（P < 0.05），单独检测时灵敏度为64%，特异性为90%，与CA125联合检测时灵敏度为91%，特异性为95%。
触珠蛋白衍生的α亚基是卵巢癌的潜在标志物，可作为CA-125的补充。基于质谱的蛋白质谱分析是筛选蛋白质标志物的有价值工具，有助于检测肿瘤相关蛋白质的翻译后修饰或异常代谢产物。然而，用特异性抗体确认蛋白质身份对于临床应用和功能研究至关重要。
