Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Proteomics Center, Medical University of South Carolina, Charleston, South Carolina.
Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, South Carolina.
Prostate. 2020 Sep;80(13):1071-1086. doi: 10.1002/pros.24031. Epub 2020 Jul 20.
The emergence of reactive stroma is a hallmark of prostate cancer (PCa) progression and a potential source for prognostic and diagnostic markers of PCa. Collagen is a main component of reactive stroma and changes systematically and quantitatively to reflect the course of PCa, yet has remained undefined due to a lack of tools that can define collagen protein structure. Here we use a novel collagen-targeting proteomics approach to investigate zonal regulation of collagen-type proteins in PCa prostatectomies.
Prostatectomies from nine patients were divided into zones containing 0%, 5%, 20%, 70% to 80% glandular tissue and 0%, 5%, 25%, 70% by mass of PCa tumor following the McNeal model. Tissue sections from zones were graded by a pathologist for Gleason score, percent tumor present, percent prostatic intraepithelial neoplasia and/or inflammation (INF). High-resolution accurate mass collagen targeting proteomics was done on a select subset of tissue sections from patient-matched tumor or nontumor zones. Imaging mass spectrometry was used to investigate collagen-type regulation corresponding to pathologist-defined regions.
Complex collagen proteomes were detected from all zones. COL17A and COL27A increased in zones of INF compared with zones with tumor present. COL3A1, COL4A5, and COL8A2 consistently increased in zones with tumor content, independent of tumor size. Collagen hydroxylation of proline (HYP) was altered in tumor zones compared with zones with INF and no tumor. COL3A1 and COL5A1 showed significant changes in HYP peptide ratios within tumor compared with zones of INF (2.59 ± 0.29, P value: .015; 3.75 ± 0.96 P value .036, respectively). By imaging mass spectrometry COL3A1 showed defined localization and regulation to tumor pathology. COL1A1 and COL1A2 showed gradient regulation corresponding to PCa pathology across zones. Pathologist-defined tumor regions showed significant increases in COL1A1 HYP modifications compared with COL1A2 HYP modifications. Certain COL1A1 and COL1A2 peptides could discriminate between pathologist-defined tumor and inflammatory regions.
Site-specific posttranslational regulation of collagen structure by proline hydroxylation may be involved in reactive stroma associated with PCa progression. Translational and posttranslational regulation of collagen protein structure has potential for new markers to understand PCa progression and outcomes.
反应性基质的出现是前列腺癌 (PCa) 进展的标志，也是 PCa 预后和诊断标志物的潜在来源。胶原蛋白是反应性基质的主要成分，其系统性和定量变化反映了 PCa 的发生过程，但由于缺乏能够定义胶原蛋白结构的工具，其仍然没有得到明确界定。在这里，我们使用一种新的胶原靶向蛋白质组学方法来研究 PCa 前列腺切除术的胶原型蛋白的区域调节。
根据 McNeal 模型，将 9 名患者的前列腺切除术分为 0%、5%、20%、70%至 80%腺体组织和 0%、5%、25%、70%癌组织质量的区域。病理学家对每个区域的 Gleason 评分、肿瘤存在百分比、前列腺上皮内瘤变和/或炎症 (INF) 百分比进行分级。对来自患者匹配的肿瘤或非肿瘤区域的组织切片进行高分辨率精确质量胶原靶向蛋白质组学选择。成像质谱用于研究与病理学家定义的区域相对应的胶原型调节。
从所有区域均检测到复杂的胶原蛋白质组。与存在肿瘤的区域相比，INF 区域的 COL17A 和 COL27A 增加。COL3A1、COL4A5 和 COL8A2 随肿瘤含量的增加而持续增加，与肿瘤大小无关。与有 INF 和无肿瘤的区域相比，肿瘤区域的胶原蛋白脯氨酸羟化 (HYP) 发生改变。与 INF 区域相比，肿瘤区域的 COL3A1 和 COL5A1 的 HYP 肽比值有显著变化（2.59±0.29，P 值：0.015；3.75±0.96，P 值：0.036）。通过成像质谱分析，COL3A1 显示出与肿瘤病理学相关的明确定位和调节。COL1A1 和 COL1A2 显示出沿肿瘤病理学的梯度调节。病理学家定义的肿瘤区域的 COL1A1 HYP 修饰明显高于 COL1A2 HYP 修饰。某些 COL1A1 和 COL1A2 肽可区分病理学家定义的肿瘤和炎症区域。
脯氨酸羟化介导的胶原结构的特定部位的翻译后调节可能与 PCa 进展相关的反应性基质有关。胶原蛋白结构的翻译后和翻译后调节可能为了解 PCa 进展和结局提供新的标志物。
