Project Summary Cachexia is a debilitating metabolic disorder that affects 50% of all cancer patients. Numerous clinical trials confirmed that the wasting of skeletal muscle mass is the hallmark of cachexia. During the course of the R37 parent grant, the research team developed the first messenger RNA (mRNA) therapy for metastatic ovarian cancer and cachexia-induced muscle wasting. It is based on lipid nanoparticles (LNPs) that deliver follistatin mRNA predominantly to cancer cells following intraperitoneal administration. The secreted follistatin protein, endogenously synthesized from delivered mRNA, efficiently reduces elevated activin A levels associated with aggressive ovarian cancer and ameliorates cachexia in this condition. By altering the cancer cell phenotype, mRNA treatment prevents malignant ascites, delays cancer progression, induces the formation of solid tumors, and preserves muscle mass in cancer-bearing mice by inhibiting negative regulators of muscle mass. Finally, the mRNA therapy provides synergistic effects in combination with cisplatin, increasing the survival of mice and counteracting muscle atrophy induced by chemotherapy and cancer-associated cachexia. Recent literature demonstrates that activin A increases the metastatic potential and decreases survival in head and neck cancers. Therefore, the research team will assess the efficacy of the developed mRNA therapy to reduce metastasis and preserve muscle mass in a new preclinical model of metastatic head-and-neck carcinoma that readily metastasizes to the lung and exhibits all the hallmark features of human cachexia. Whilst the loss of lean muscle mass is the hallmark of cancer cachexia, treatment for cachectic patients must also comprise therapeutic strategies that target systemic inflammation and stimulate appetite to ensure adequate energy and protein consumption. The research team will also develop the appetite-stimulatory therapy based on the above-discussed LNPs loaded with mRNA coding for both ghrelin and its specific O-acyltransferase (GOAT, required for full ghrelin activation). Previous reports suggest that ghrelin, a gut-secreted hormone, is a potential therapeutic agent for the treatment of appetite and weight loss in patients with cachexia. The proposed study will evaluate the efficacy of ghrelin mRNA-based therapy to improve food intake, body composition, and survival in a murine pancreatic cancer model of cachexia. Finally, anti-inflammatory therapy for the treatment of systemic inflammation in cancer cachexia will be developed using anti-inflammatory drug-loaded nanoparticles that accumulate efficiently at the site of inflammation following systemic administration. The research team has already constructed polymeric nanoparticles equipped with peptides as a targeting moiety for vascular cell adhesion molecule 1 (VCAM1) that is overexpressed in endothelial cells during inflammatory insults, with particularly high expression in hypothalamic centers regulating a...