Effect of disruption of IL-6 in cachectic C26 tumor on gene expression

The IL-6 was reported as a key cachectic factor in mice inoculated with colon carcinoma 26 (C26) cells, a widely used cancer cachexia model. However, we identified We found that the growth of IL-6 KO tumors was dramatically delayed. More strikingly, while IL-6 KO tumors eventually reached the similar size as wild-type tumors, cachexia still took place, despite no elevation in circulating IL-6. We further showed that IL-6 promotes tumor growth by facilitating immune evatioon but is dispensable for cachexia. To investigate the effect of IL-6 knock out (KO) in cachectic C26 (cxC26) tumor, we constructed C26 IL-6 KO cells using CRISPR/Cas9 and isolated a subclone (cxC26 IL6KOs1) . Then, we implanted wild-type (cxC26 scr) and IL-6 KOs1 cells into CD2F1 male mice. The tumor samples were isolated when the mice developed cachexia (more than 15% of body weight loss) and perfromed bulk RNA-seq.