Reducing squalene epoxidase by the aging-dependent intra-tissue cholesterol accumulation is associated with increased colorectal cancer patient severity in high-risk populations

ObjectiveRecently, we demonstrated cholesterol accelerating colorectal cancer (CRC) progression via squalene epoxidase (SQLE) reduction, activating the β-catenin oncogenic pathway while downregulating the p53 pathway, mediated by the inhibition of GSK3β activity (GSK3βpS9). However, the interrelationship between cholesterol increase and CRC progression with aging has never been determined.DesignWe utilized case data from public databases and human specimens to assess the relationship between cholesterol accumulation and CRC progression with aging. Digital image analysis-machine learning with multiplex fluorescence-immunohistochemistry evaluated the effects of SQLE, p53WT, p53MT, and GSK3βpS9(hereafter candidates) on the survival of CRC patients. Also, the prognostic and diagnostic abilities were assessed by a time-dependent receiver operating characteristic (timeROC) and a ROC curve with and without the discriminant score for the candidates as a single or whole, respectively.ResultsWe found an accumulation of cholesterol and cholesteryl ester in tissues with aging, which led to the acceleration of CRC progression through substantial decreases of SQLE, p53WT, p53MTexpressions and inhibition of GSK3β activity in advanced CRCs. Retrospective studies demonstrated that SQLE significantly impacted the shortened progression-free survival of the population with progressive pathological severity and high CRC risk beyond the age of 50. Clinical assays further showed the excellent prognostic and diagnostic abilities of SQLE and GSK3βpS9but also the substantial diagnostic potential of the combined candidate for the aged high-risk CRC population.ConclusionWe provide new insights into the relationship between cholesterol increase and CRC progression with aging and identify valuable biomarkers for aged populations with high-risk CRC.