Gibbard, Daniel F.

Abstract Metabolic vulnerabilities in cancer have been targeted primarily to suppress tumor growth, but less is known about the metabolic requirements for tumor cell invasion. Here we report that lipid catabolism by cytosolic and lysosomal lipases supports pancreatic cancer cell invasion through both overlapping and distinct functional and metabolic mechanisms. Lysosomal acid lipase (LAL)-dependent lipid droplet catabolism promotes invadopodia formation and stabilization, enabling extracellular matrix degradation. In addition to modulating cellular energetics, lipidomics revealed that lipid droplet catabolism regulates cholesterol and membrane phospholipid levels. Using spatially resolved biosensors and cholesterol imaging, we found that lysosomal lipid catabolism occurs at invadopodia and sustains local ATP and membrane cholesterol. These findings identify spatially organized lipid catabolism as a mechanism that couples local energetics and membrane remodeling during the earliest steps of pancreatic cancer cell invasion.

Cancer cachexia, and its associated complications, represent a large and currently untreatable roadblock to effective cancer management. Many potential therapies have been proposed and tested—including appetite stimulants, targeted cytokine blockers, and nutritional supplementation—yet highly effective therapies are lacking. Innovative approaches to treating cancer cachexia are needed. Members of the Kruppel-like factor (KLF) family play wide-ranging and important roles in the development, maintenance, and metabolism of skeletal muscle. Within the KLF family, we identified KLF10 upregulation in a multitude of wasting contexts—including in pancreatic, lung, and colon cancer mouse models as well as in human patients. We subsequently interrogated loss-of-function of KLF10 as a potential strategy to mitigate cancer associated muscle wasting. In vivo studies leveraging orthotopic implantation of pancreas cancer cells into wild-type and KLF10 KO mice revealed significant preservation of lean mass and robust suppression of pro-atrophy muscle-specific ubiquitin ligases Trim63 and Fbxo32, as well as other factors implicated in atrophy, calcium signaling, and autophagy. Bioinformatics analyses identified Transforming growth factor beta (TGF-β), a known inducer of KLF10 and cachexia promoting factor, as a key upstream regulator of KLF10. We provide direct in vivo evidence that KLF10 KO mice are resistant to the atrophic effects of TGF-β. ChIP-based binding studies demonstrated direct binding to Trim63 , a known wasting-associated atrogene. Taken together, we report a critical role for the TGF-β/KLF10 axis in the etiology of pancreatic cancer–associated muscle wasting and highlight the utility of targeting KLF10 as a strategy to prevent muscle wasting and limit cancer-associated cachexia.

Abstract Cancer cachexia, and its associated complications, represent a large and currently untreatable roadblock to better cancer therapy. Many potential therapies have been suggested and tested - including appetite stimulants, targeted cytokine blockers, and nutritional supplementation, but effective therapies have still not found a place in the clinic. Thus, a new approach to treating cancer cachexia is warranted. Members of the Kruppel-like factor family play wide-ranging and important roles in the development, maintenance, and metabolism of muscle. Upon review both our own and multiple publically available datasets, we identified KLF10 upregulation in a multitude of cachectic muscles - including in pancreatic, lung, and colon cancer mouse models and in human cachexia patients. Thus, in this study, we interrogated loss-of-function of KLF10 in the context of pancreatic cancer associated muscle wasting. Ex vivo experiments on satellite cells isolated from KLF10 Knockout (KO) mice showed resistance to the effect of KPC conditioned media on atrophy. In vivo studies using a KLF10 KO mouse model showed that upon orthotopic implantation of T4-KPC cells, the mice demonstrated a significant preservation of lean mass and significant alterations in the expression of muscle-specific ubiquitin ligases Trim63 and Fbxo32, as well as other genes implicated in atrophy, calcium signaling, and autophagy. Pathway analysis of RNA-seq data from these mice identified TGF-B, a known inducer of KLF10, as an important upstream regulator of the response. Further in vivo experimentation showed KLF10 KO mice to be resistant to the atrophic effects of TGF-B injections. In conclusion, we report a novel role of KLF10 in the manifestation of cachexia in pancreatic cancer. Citation Format: Daniel F. Gibbard, Aneesha Dasgupta, Rebecca E. Schmitt, Alexandra M. Ducharme, Paige C. Arneson, Elizabeth S. Bruinsma, John R. Hawse, Jason D. Doles. TGF-B/KLF10 signaling regulates muscle wasting in pancreatic cancer cachexia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3985.