Quantitative determination of expression of the prostate cancer protein α-methylacyl-CoA racemase using automated quantitative analysis (AQUA) -: A novel paradigm for automated and continuous biomarker measurements
Quantitative determination of expression of the prostate cancer protein α-methylacyl-CoA racemase using automated quantitative analysis (AQUA) -: A novel paradigm for automated and continuous biomarker measurements
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DOI：
10.1016/s0002-9440(10)63171-9
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发表时间：
2004-03-01
影响因子：
6
通讯作者：
Rimm, DL
中科院分区：
文献类型：
--
作者：
Rubin, MA;Zerkowski, MP;Rimm, DL
尽管经过多年的发现和验证尝试，但很少有分子生物标志物在临床环境中获得认可。通过免疫组织化学评估的基于组织的标记物存在高度的观察者间和观察者内变异性。该领域的一项最新进展是 AQUA 的开发，它是一种基于分子的蛋白质表达定量评估方法，有望实现这一过程的自动化。该系统集成了一组算法，可以对组织样本进行快速、自动化、连续和定量分析，包括肿瘤与基质成分的分离以及信号的亚细胞定位。本研究使用 AQUA 系统评估最近描述的前列腺癌生物标志物 α-甲基酰基辅酶 A 消旋酶 (AMACR)，并确定该标志物的定量测量作为前列腺癌诊断手段的有效性。使用包含多种前列腺组织的前列腺癌进展组织微阵列 9 将 AQUA 直接与使用 P504s 单克隆抗体对 AMACR 蛋白表达进行的标准免疫组织化学评估进行比较。两种方法产生相似的结果，显示 AMACR 蛋白表达在临床局限性前列腺癌中最强，其次是转移性肿瘤样本。通过免疫组织化学，大多数组织样本的良性前列腺组织被归类为阴性。然而，使用 AQUA 系统可以在标准 1:25 稀释度和 1:250 稀释度下检测到低水平的 AMACR，这是光学显微镜无法检测到的。 AQUA 系统还能够从良性前列腺组织样本中区分泡沫腺前列腺癌，已知泡沫腺前列腺癌的 AMACR 表达低于典型腺泡前列腺癌。最后，绘制接受者操作特征曲线以确定 AMACR AQUA Z 评分（标准化 AQUA 评分）的特异性，以预测给定的组织微阵列样本含有癌症。曲线下面积计算为 0.90（P < 0.00001；95% Cl，0.84 至 0.95）。当 AMACR AQUA Z 得分为 -0.3 时，被分类为前列腺癌的 70 个样本中的 91% 被正确分类，无需病理学家检查组织微阵列载玻片的干预。总之，AQUA 系统可以对各种前列腺组织样本进行 AMACR 的连续测量。未来，AMACR AQUA Z 评分可能有助于前列腺组织生物标志物的自动筛查和评估。
Despite years of discovery and attempts at validation, few molecular biomarkers achieve acceptance in the clinical setting. Tissue-based markers evaluated by immunohistochemistry suffer from a high degree of inter- and intraobserver variability. One recent advance in this field that promises to automate this process is the development of AQUA, a molecular-based method of quantitative assessment of protein expression. This system integrates a set of algorithms that allows for the rapid, automated, continuous, and quantitative analysis of tissue samples, including the separation of tumor from stromal elements and the subcellular localization of signals. This study uses the AQUA system to assess a recently described prostate cancer biomarker, alpha-methylacyl-CoA-racemase (AMACR), and to determine the effectiveness of the quantitative measurement of this marker as a means for making the diagnosis of prostate cancer. Using a prostate cancer progression tissue microarray containing a wide range of prostate tissues 9 AQUA was directly compared to standard immunohistochemical evaluation for AMACR protein expression using the P504s monoclonal antibody. Both methods produced similar results showing AMACR protein expression to be strongest in the clinically localized prostate cancer, followed by the metastatic tumor samples. Benign prostate tissue was categorized as negative for most tissue samples by immunohistochemistry. However, AMACR was detectable using the AQUA system at low levels using the standard 1:25 dilution but also at 1:250 dilution, which is not detectable by light microscopy. The AQUA system was also able to discriminate foamy gland prostate cancers, which are known to have a lower AMACR expression than typical acinar prostate cancers, from benign prostate tissue samples. Finally, a receiver-operating-characteristic curve was plotted to determine the specificity of the AMACR AQUA Z-score (normalized AQUA score) to predict that a given tissue microarray sample contains cancer. The area under the curve was calculated at 0.90 (P < 0.00001; 95% Cl, 0.84 to 0.95). At an AMACR AQUA Z-score score of -0.3, 91% of the 70 samples classified as prostate cancer were correctly categorized without the intervention of a pathologist reviewing the tissue microarray slide. In conclusion, the AQUA system provides a continuous measurement of AMACR on a wide range of prostate tissue samples. in the future, the AMACR AQUA Z-score may be useful in the automated screening and evaluation of prostate tissue biomarkers.