School of Pharmacy, Shenyang Pharmaceutical University, 103 Wenhua Road, Shenyang 110016, China.
Metabolomics Core Facility of RHLCCC, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, United States.
J Chromatogr A. 2020 Mar 15;1614:460723. doi: 10.1016/j.chroma.2019.460723. Epub 2019 Nov 18.
Quantitative determination of endogenous compounds in biological samples has still been challenged by the absence of authentic blank matrix. Alternative strategy of surrogate matrix for preparing reference samples are prevalent due to its low cost and high availability. However, the evaluation system of surrogate matrix is not perfect. Herein, a novel multifunctional isotopic standards based steroidomics strategy was developed. Isotope-labeled standards were used not only as internal standards but also for the evaluation the feasibility of surrogate matrix, which improved the accuracy of assessment and could provide a new prospect for the quantitative analysis of endogenous compounds. Based on this approach, a detailed optimization from LC separation, MS detection to extraction conditions for global steroids in the steroidogenesis was firstly carried out. Characteristics and regularities of steroids in LC-MS were summarized to make references for further targeted or untargeted steroidomics study. Then eighteen steroids were quantified with high accuracy and high sensitivity in plasma from four types of cancer patients and healthy subjects using 1% BSA in PBS as surrogate matrix. And multi-steroids indexes with the best discriminating ability for lung, colorectal, breast and gastric cancer in different genders were identified successfully with Student's t-test, PLS-DA and logistic regression- ROC curve analysis. Finally, efficient cancer screening workflow was established by integrating the amine submetabolomics and lipidomics data of our previous studies. Taken together, the integrated steroidomics strategy could shed a light on the guidance for further steroidome as well as other endogenous compounds analysis and may provide a powerful tool for cancer diagnosis.
定量测定生物样品中的内源性化合物仍然受到缺乏真实空白基质的挑战。替代基质的替代策略由于其低成本和高可用性而得到广泛应用。然而，替代基质的评估系统并不完善。本文开发了一种基于多功能同位素标记标准的类固醇组学策略。同位素标记标准不仅可用作内标，还可用于评估替代基质的可行性，从而提高了评估的准确性，并为内源性化合物的定量分析提供了新的前景。在此基础上，首次对类固醇生成中的全局类固醇进行了从 LC 分离、MS 检测到提取条件的详细优化。总结了 LC-MS 中类固醇的特点和规律，为进一步的靶向或非靶向类固醇组学研究提供参考。然后，使用 1%BSA 在 PBS 中的替代基质，对来自 4 种癌症患者和健康受试者的血浆中的 18 种类固醇进行了高精度和高灵敏度的定量检测。采用 Student's t 检验、PLS-DA 和逻辑回归-ROC 曲线分析，成功确定了不同性别中对肺癌、结直肠癌、乳腺癌和胃癌具有最佳区分能力的多类固醇指标。最后，通过整合我们之前研究中的胺亚代谢组学和脂质组学数据，建立了有效的癌症筛选工作流程。总之，综合类固醇组学策略可以为进一步的类固醇组学以及其他内源性化合物分析提供指导，并可能为癌症诊断提供有力工具。
