Compositional Analysis of Walnut Lipid Extracts and Properties as an Anti-cancer Stem Cell Regulator via Suppression of the Self-renewal Capacity

Abstract

Colon cancer is a leading cause of cancer-related deaths worldwide. Effects of walnut (Juglans regia L.) lipid extracts (WLEs) on the self-renewal capacity of cancer stem cells (CSCs) in colon cancer were investigated. The dominant component of WLEs was alpha-linoleic acid (64.6%), followed by a-linolenic acid (14.6%), and oleic acid (12.6%). A higher concentration of gamma-tocopherol (37.1%) was also present than of alpha-tocopherol (0.6%). CD133(+)CD44(+)CSCs treated with WLEs showed inhibition of colony formation and sphere formation, indicating a decrease in the self-renewal capacity. Treatment with WLEs also resulted in down-regulation of protein levels, including Notch1, phospho-GSK3 beta (p-GSK3 beta), and beta-catenin, which are associated with CSCs and the self-renewing capacity. WLEs rich in essential fatty acids and gamma-tocopherol can exert therapeutic actions on colon cancer via targeting of CSCs.