Abstract 4769: Phospho-YAP (Ser127) overexpression is associated with sporadic advanced adenomas: The Tennessee Colorectal Polyp Study
Authors: Fan Lei , Guo Xingyi , Washington Mary Kay , Shi Jiajun , Ness Reid M. , Liu Qi , Wen Wanqing , Liu Xiao , Cai Qiuyin , Zheng Wei , Coffey Robert J. , Shrubsole Martha J. , Su Timothy 
Published: March 2024

Abstract
About 70-80% of sporadic colorectal cancers (CRCs) harbor APC mutations. Whether specific characteristics of APC mutation or APC-related signaling pathways contribute to tumor initiation, advanced progression, and recurrence in the precancerous lesions remain to be elucidated. This study included145 sporadic precancerous adenomas from the Tennessee Colorectal Polyp Study. Expression of six APC-related proteins (β-catenin, p-YAP, CtBP, EB1, Asef, and N-terminal APC) in adenoma and non-tumor tissues (n=22) were quantitatively detected by immunohistochemistry. Targeted sequencing of APC was done for 108 adenomas. Metachronous adenoma status was obtained from chart review. YAP-correlated genes and their functional enrichment analysis were conducted using gene expression data of 326 adenomas from the Gene Expression Omnibus database. We found that nuclear β-catenin and p-YAP overexpression only existed in adenoma tissue, correlated with each other (r=0.26, P=0.0018), and associated with APC mutations (P=0.05). P-YAP was strongly associated with odds of large adenomas (OR=14.25, 95%CI=3.32-61.18, P trend&lt;0.0001), villous growth pattern (OR=58.71, 95%CI=10.49-328.61, P trend&lt;0.0001) and advanced adenomas (OR=12.62, 95%CI 4.57-34.86, P trend&lt;0.001), and showed a significant interaction with nuclear β-catenin on advanced tumor (OR=16.82, 95%CI 4.41-64.08, P&lt;0.0001). After adjusting for selected covariates and mutually adjusting for biomarkers with P&lt;0.20 in crude models, p-YAP overexpression remained significantly associated with advanced adenomas (OR=12.31, 95% CI=3.78-40.10, P trend&lt;0.0001). YAP-correlated genes were significantly enriched in autophagy, unfolded protein response, and sirtuin pathways with predominantly pro-tumorigenic alterations. APC mutation and selected biomarkers were not significantly associated with metachronous adenoma. In conclusion, p-YAP overexpression might be a promising biomarker for high-risk sporadic adenoma. In addition to its synergistic effect with nuclear β-catenin, p-YAP may play tumorigenic roles through interaction with other cancer pathways in human sporadic adenoma. This study provided new evidence for oncogenic effects of p-YAP in human sporadic adenomas and shed light on the complex network of Hippo, Wnt, and other oncogenic signaling pathways.
Citation Format: Lei Fan, Xingyi Guo, Mary Kay Washington, Jiajun Shi, Reid M. Ness, Qi Liu, Wanqing Wen, Xiao Liu, Qiuyin Cai, Wei Zheng, Robert J. Coffey, Martha J. Shrubsole, Timothy Su. Phospho-YAP (Ser127) overexpression is associated with sporadic advanced adenomas: The Tennessee Colorectal Polyp Study [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 4769.