Abstract 6445: Exploring the relationship between PSCA and PD-L1 by a comprehensive tumor immunohistochemical analysis

Abstract

Abstract Prostate Stem Cell Antigen (PSCA) is a well-established diagnostic marker in various cancers and a promising target for immunotherapy. Programmed Death-Ligand 1 (PD-L1) plays a crucial role in cancer immune regulation and is known to influence patient response to checkpoint inhibitors. The objective of this study is to elucidate the relationship between PSCA and PD-L1 in diverse cancer types and to provide valuable insights for the development of an effective immunotherapy strategy. To accomplish this, immunohistochemical (IHC) analysis was conducted on paraffin-embedded Cytosections obtained from 20 lung cancers, 20 prostate cancers, 32 bladder cancers, and 20 normal tissues for each respective cancer type. Antibodies generated by Origene were utilized to detect the expression of PSCA and PD-L1 on the cell surface. The IHC results of tumor tissue were standardized against corresponding normal samples, and the correlation between these two genes was statistically analyzed using analysis of variance (ANOVA). The findings reveal a significant positive correlation between the expression of PSCA and PD-L1 (r=+0.78, P=0.016), suggesting an underlying mechanism driving their co-expression in the studied cancers. Understanding PSCA and PD-L1 coexpression in bladder, lung, and prostate cancers has great potential for informing tailored immunotherapies. Future research should explore functional consequences within the tumor microenvironment, advancing precision immunotherapy for improved outcomes in these challenging malignancies. Citation Format: Yichen Guo, Rachel Gonzalez, Jina Yom, Bailey Gilmore, Tianli Qu, Xiaomin Hu, Andy (Xi) Han, Zhaoying Guo, Eden Zewdu, Xuan Liu, Wei Fu. Exploring the relationship between PSCA and PD-L1 by a comprehensive tumor immunohistochemical analysis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6445.