The effect of sex on IL‐6 regulation of cancer cachexia progression in the Apc min/+ mouse (704.2)

Abstract

Cachexia is a condition that arises secondary to many chronic diseases and accounts for more than 20% of cancer‐related deaths. Cachexia occurs in both sexes, but research into its etiology and progression has been almost exclusively in the male. Our lab has previously shown that body weight loss in the male Apc min/+ mouse is closely associated with plasma IL‐6 and triglyceride levels as well as tumor burden. The purpose of the present study was to determine if sex alters IL‐6 regulation of cachexia progression in Apc min/+ mice. 24 female Apc min/+ mice were monitored during the development of cachexia until sacrifice at 20 weeks of age. Plasma IL‐6 and triglycerides as well as intestinal polyps were quantified. Body weight loss from peak ranged from 0% to 21%, with 30% of mice becoming severely cachectic. Plasma IL‐6 levels varied from 4.4‐39.7 pg/ml, which is comparable to the male. Similar to the male, body weight loss was correlated with tumor number (p=0.01). Unlike the male, there was neither a relationship between body weight loss and plasma IL‐6 or triglyceride levels; nor between tumor number and plasma IL‐6 level. Interestingly, muscle mass loss was inversely correlated with plasma IL‐6 level (p=0.03), which is contrary to the male. We present evidence that sex can affect the relationship between muscle mass loss, cachexia development, and plasma IL‐6 in the Apc min/+ mouse, which may impact therapeutics for cachexia.