Table 3_Quantitative proteomic analysis reveals potential serum diagnostic markers for colorectal adenoma.xlsx

IntroductionColorectal cancer (CRC) is one of the leading causes of cancer-related death, and most CRCs arise from colorectal adenomas. Early detection and removal of precancerous lesions during the adenoma-carcinoma sequence can significantly reduce CRC risk. However, current clinical practice lacks rapid, noninvasive screening tools for reliable adenoma detection.
MethodsProteomic analysis was performed on serum samples from patients with inflammatory polyps (non-neoplastic), patients with adenomas, and healthy controls to identify key differentially expressed proteins capable of distinguishing adenoma patients. The alterations in these candidate proteins were further validated by ELISA to evaluate their potential as diagnostic biomarkers for colorectal adenoma.
ResultsIn two independent cohorts, we identified two candidate biomarkers, apolipoprotein A4 (APOA4) and filamin A (FLNA), through a multi-step selection process involving ANOVA p-value screening, sparse partial least squares discriminant analysis (sPLS-DA), and LASSO regression analysis. These candidates were subsequently validated in a third cohort using ELISA. The ELISA results for APOA4 were discordant with the liquid chromatography-tandem mass spectrometry (LC-MS/MS) findings. In contrast, FLNA levels measured by ELISA showed a progressive decrease from healthy controls to patients with inflammatory polyps and further to those with adenomas. We propose FLNA as a potential biomarker for the diagnosis of colorectal adenomas. The areas under the ROC curves exceeded 0.7 for both key clinical comparisons: 0.810 for adenomas versus healthy controls, and 0.734 for adenomas versus inflammatory polyps.
DiscussionOverall, this study not only enhances our understanding of the serum proteome in colorectal adenoma but also identifies FLNA as a promising biomarker for its clinical diagnosis.

引言
结直肠癌（CRC）是癌症相关死亡的主要诱因之一，且绝大多数结直肠癌由结直肠腺瘤恶变而来。在腺瘤-癌变序列阶段及早发现并切除癌前病变，可显著降低结直肠癌发病风险。然而当前临床实践中，缺乏能够可靠检出腺瘤的快速非侵入性筛查工具。

方法
本研究对炎性息肉（非肿瘤性）患者、腺瘤患者及健康对照的血清样本开展蛋白质组学分析，以筛选可区分腺瘤患者的关键差异表达蛋白。随后通过酶联免疫吸附实验（ELISA）对候选蛋白的表达变化进行验证，评估其作为结直肠腺瘤诊断生物标志物的潜力。

结果
本研究通过包含方差分析（ANOVA）P值筛选、稀疏偏最小二乘判别分析（sPLS-DA）及套索（LASSO）回归分析在内的多步筛选流程，在两个独立队列中筛选出载脂蛋白A4（APOA4）和细丝蛋白A（FLNA）两种候选生物标志物。随后通过ELISA在第三个独立队列中对这两种候选标志物进行了验证。APOA4的ELISA检测结果与液相色谱-串联质谱（LC-MS/MS）的检测结果并不一致。与之相反，ELISA检测的FLNA水平呈现出从健康对照、炎性息肉患者到腺瘤患者逐步降低的趋势。本研究认为FLNA可作为结直肠腺瘤诊断的潜在生物标志物。在两项关键临床对照中，受试者工作特征（ROC）曲线下面积均超过0.7：腺瘤患者与健康对照的ROC曲线下面积为0.810，腺瘤患者与炎性息肉患者的ROC曲线下面积为0.734。

讨论
综上，本研究不仅加深了我们对结直肠腺瘤患者血清蛋白质组的认识，同时还筛选出FLNA作为一种极具应用前景的结直肠腺瘤临床诊断生物标志物。