Abstract 5564: SerpinE2: A potential biomarker for urological cancers

Abstract SerpinE2, also known as protease nexin-1, is an extracellular serine protease inhibitor modulating the activity of serine proteases such as thrombin, plasmin, urokinase-type plasminogen activator and trypsin. Dysregulation between extracellular serine proteases and their cognate inhibitors has been implicated in malignant progression, making serpins promising biomarkers for tumor progression and prognosis. SerpinE2 is upregulated in many cancers and promotes tumor invasion and metastasis. In this study, we analyzed serpinE2 expression by immunohistochemistry on tissue microarrays comprising of samples from prostate, bladder and kidney cancers. The studied samples were clinically hard-to-risk stratify and thus relevant for biomarker studies. We aimed to study the association of serpinE2 expression with survival and clinicopathological features in all three cancers, and evaluate its potential as an immunohistochemical biomarker. In the case of bladder cancer, association of serpinE2 expression with response to neoadjuvant chemotherapy was also assessed. We found that although the strong expression of serpinE2 was related to more aggressive prostate cancers (p = 0.017) and high grade bladder cancers (p = 0.034), it was not associated with relapse, treatment response or survival of prostate and bladder cancer patients. In renal cancer, on the contrary, serpinE2 expression was significantly lower in patients with tumor relapse (p = 0.048) and high expression predicted favorable disease-specific survival (p = 0.013). Our findings help understanding the functional role of serpinE2 in cancer progression and guide the prognostic biomarker research of serpinE2, particularly for prediction of renal cancer-specific survival. Citation Format: Ruusu-Maaria Kovanen, Netta Koskinen, Timo-Pekka Lehto, Antti Rannikko, Tuomas Mirtti, Hannu Koistinen. SerpinE2: A potential biomarker for urological cancers. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5564.