Howng Bruce, Winter Michael B, LePage Carol, Popova Irina, Krimm Michael, Vasiljeva Olga
CytomX Therapeutics, Inc., San Francisco, CA 94080-1913, USA.
Pharmaceutics. 2021 Sep 2;13(9):1390. doi: 10.3390/pharmaceutics13091390.
Proteases are involved in the control of numerous physiological processes, and their dysregulation has been identified in a wide range of pathologies, including cancer. Protease activity is normally tightly regulated post-translationally and therefore cannot be accurately estimated based on mRNA or protein expression alone. While several types of zymography approaches to estimate protease activity exist, there remains a need for a robust and reliable technique to measure protease activity in biological tissues. We present a novel quantitative ex vivo zymography (QZ) technology based on Probody therapeutics (Pb-Tx), a novel class of protease-activated cancer therapeutics that contain a substrate linker cleavable by tumor-associated proteases. This approach enables the measurement and comparison of protease activity in biological tissues via the detection of Pb-Tx activation. By exploiting substrate specificity and selectivity, cataloguing and differentiating protease activities is possible, with further refinement achieved using protease-specific inhibitors. Using the QZ assay and human tumor xenografts, patient tumor tissues, and patient plasma, we characterized protease activity in preclinical and clinical samples. The QZ assay offers the potential to increase our understanding of protease activity in tissues and inform diagnostic and therapeutic development for diseases, such as cancer, that are characterized by dysregulated proteolysis.
蛋白酶参与众多生理过程的调控，其失调已在包括癌症在内的多种病理状况中被发现。蛋白酶活性通常在翻译后受到严格调控，因此不能仅基于mRNA或蛋白质表达来准确估计。虽然存在几种用于估计蛋白酶活性的酶谱分析方法，但仍需要一种强大且可靠的技术来测量生物组织中的蛋白酶活性。我们提出了一种基于前体药物疗法（Pb-Tx）的新型定量离体酶谱分析（QZ）技术，Pb-Tx是一类新型的蛋白酶激活型癌症治疗药物，其中包含可被肿瘤相关蛋白酶切割的底物连接子。这种方法能够通过检测Pb-Tx的激活来测量和比较生物组织中的蛋白酶活性。通过利用底物特异性和选择性，可以对蛋白酶活性进行分类和区分，使用蛋白酶特异性抑制剂可进一步优化。利用QZ分析以及人肿瘤异种移植模型、患者肿瘤组织和患者血浆，我们对临床前和临床样本中的蛋白酶活性进行了表征。QZ分析有可能增进我们对组织中蛋白酶活性的理解，并为以蛋白水解失调为特征的疾病（如癌症）的诊断和治疗发展提供信息。
