Abstract 2113: The age-dependent intratissue accumulation of cholesterol, resulting in reduced squalene epoxidase, is associated with a high colorectal cancer risk population

Abstract Objective: we recently reported that cholesterol accelerates CRC aggravates via the dissociation of GSK3β/p53 by the degradation of squalene epoxidase (SQLE). However, despite its clinical reports, the underlying mechanisms between age, cholesterol, and CRC aggravation have never been evaluated in human cohorts. Design: tissue lysates and human specimens collected prospectively from CRC patients and controls were grouped according to CRC grade and divided into two groups based on age 50, the average risk for CRC. The intra-tissue content of total cholesterol and cholesteryl ester were measured using CRC lysates. We then used fluorescence-based multiplex immunohistochemistry with digital image analysis and machine learning to measure the quantitative expression of SQLE, GSK3β, p53wt, and p53mt. Results: through an epidemiological study, we estimated age-dependent increases in CRC incidence and the percentage of a group with high cholesterol around age 50. Considering this age-dependency, we demonstrated age and CRC-grade-dependent manner cholesterol accumulated inside CRC tissues, SQLE, p53wt, and p53mt degraded, and GSK3β inactivated. SQLE and GSK3β were clinically associated with increased risk and showed good diagnostic and prognostic performance in CRC patients older than 50. Furthermore, the combined value for four variables exhibited superior diagnostic performance in discriminating from CRC patients after age 50 to controls. Conclusion: this study provides new biological perceptions explaining the effects of age in the progression of CRC aggravation and potential biomarkers associated with a high CRC-risk population. Citation Format: Soo Young Jun, Ji-Yong Yoon, Jeong-Ju Lee, Nam-Soon Kim. The age-dependent intratissue accumulation of cholesterol, resulting in reduced squalene epoxidase, is associated with a high colorectal cancer risk population [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 2113.