A novel preclinical model of human lung cancer cachexia

Most patients with lung cancer are afflicted with cancer cachexia (CC), a syndrome characterized by wasting of muscle and fat tissues, which leads to poor treatment response and increased mortality. Pre-clinical models used to study CC often do not mimic the human condition, which may explain why there are no approved treatments for CC. To overcome this barrier, we sought to develop a model of lung CC that better recapitulates the pathoetiological characteristics of human lung CC using mice with a tamoxifen-inducible, lung epithelial cell (club cell)-specific KrasG12D allele ( G12D mice). We hypothesized that this model would mimic human CC in tumor location and burden, rate of progression, and tumor-driven tissue wasting. Following induction by tamoxifen injection, adenocarcinomas developed in the terminal bronchioles as early as 3.5 weeks post-induction and were accompanied by loss of 15% of animal body weight over a 12-week period. This weight loss began at 6 weeks and yielded a slow rate of CC progression (-1.9%/week) relative to currently available lung CC models (-5-10%/week). Body weight loss resulted from reductions in hindlimb muscle mass (18-30%) and profound depletion of inguinal and gonadal adipose tissue depots (60-70%) compared to age-matched wild-type (WT) littermates. At 6 weeks post-induction, fat tissue was reduced at the tissue and cellular levels while reductions in hindlimb muscle weight and fiber size were not observed. This fat loss corresponded with increased serum glycerol levels at 6 and 12 weeks, a metabolic characteristic that was also found in patients with lung cancer receiving treatment. Lung organoids were developed from G12D and WT mice. G12D organoids exhibited similarities in gene expression to human lung tumors ( RNAseq) and their conditioned medium (CM) elicited glycerol release from cultured 3T3L1 adipocytes compared to CM from WT organoids, suggesting that tumor-derived factors may contribute to early adipose tissue atrophy. Collectively, these findings suggest that G12D mice may be a valuable model, well-suited to identify mechanisms leading to CC and test preventative therapies. NIH R01 AR065826(MJT), NCI R21 CA283492(MJT), T32- HL076122-18(DBS/MEP), R01 CA273238 (YJ-H) and the University of Vermont Cancer Center. Funding support for RNAseq provided by Zymo Impact Initiative Grant (DBS). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.