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Biology subjects

Knos, C.

Publications and source records attributed to Knos, C..

3 recordsLinked to original sources

Plasma proteomics identifies an IL-6–associated SAA axis linked to muscle wasting in patients with cancer cachexia

Nearly half of patients with advanced lung cancer develop cachexia, a debilitating syndrome that worsens prognosis. We conducted longitudinal clinical and plasma proteomic profiling of 67 patients with non-small cell lung cancer, with and without cachexia, during first-line treatment. Patients with cachexia at diagnosis exhibited elevated risk of hospitalization and treatment-delaying toxicity. At diagnosis, 128 plasma proteins were upregulated and 67 downregulated in cachectic relative to non-cachectic patients. Longitudinal assessments of body composition, physical performance, metabolism, clinical outcomes, and nutritional risk revealed distinct fat and muscle wasting phenotype trajectories. 71 proteins were associated with fat loss, 92 with muscle loss, and 177 with concurrent muscle and weight loss. We identified and functionally validated 8 plasma proteins linked to muscle loss and adverse clinical outcomes. In a separate cohort of 147 patients with advanced pancreatic cancer receiving the interleukin-6 (IL-6) inhibitor tocilizumab, pharmacological suppression of serum amyloid A (SAA) levels following IL-6 inhibition suggests a systemic IL-6-SAA axis. These results collectively highlight SAA1 and SAA2 as IL-6-driven, cachexia-associated factors that reduce human myotube width. These findings uncover new potential therapeutic targets for cachexia.

Systems Biology↗

Proteomic and phospho-proteomic longitudinal signatures of human skeletal muscle in lung cancer cachexia

Weight loss is a potentially deadly hallmark of many cancers, including lung cancer. In particular, the loss of skeletal muscle mass and function impairs survival and lowers quality of life. Despite being a major determinant of prognosis, the molecular drivers of muscle wasting remain ill-defined. Therefore, there is a critical need for human molecular data to support the development of effective therapies for this currently untreatable condition. Here, we utilize cutting-edge proteomics technology to longitudinally map the proteome and phosphoproteome of skeletal muscle from patients with newly diagnosed, advanced-stage non-small cell lung cancer during their treatment. Leveraging deep in vivo clinical phenotyping of activity, body composition, muscle quality, and nutritional risk, we identified 118/174 muscle proteins/phospho-sites associated with cachexia at diagnosis with indications of sexual dimorphism. Treatment altered 278 proteins and 1,155 phospho-sites, of which 137/91 proteins/phospho-sites were associated with muscle wasting. Our findings highlight disrupted calcium, anabolic, and stress signalling, alongside extracellular matrix and mitochondrial alterations, as key molecular features of cachexia in non-small cell lung cancer. These clinically anchored proteomic and phosphoproteomic signatures provide potential targets for future research.

molecular biology↗

Pathophysiological remodeling of the skeletal muscle microenvironment in patients with lung cancer

Background Muscle wasting, systemic inflammation, and functional decline are highly prevalent and detrimental in patients with advanced-stage non small cell lung cancer (NSCLC). Methods: In this cross sectional study, we investigated NSCLC associated muscle remodeling by analyzing skeletal muscle biopsies from patients with NSCLC (n = 18) and matched controls (n = 18) using quantitative proteomics, histology, fluorescence-activated cell sorting, gene expression profiling, and high resolution respirometry. Findings: NSCLC muscle was characterized by type II muscle fiber atrophy, greater collagen deposition, and redistribution of lipids to the extracellular matrix (ECM), together with remodeling of the inflammatory, immune, ECM and mitochondrial proteome. Additionally, mitochondrial respiratory capacity and morphology were altered in patients with NSCLC, which was associated with increased oxidative stress and dysregulated calcium handling. Concomitantly, we detected STAT3 activation and immune cell alterations, which may negatively impact skeletal muscle health in patients with NSCLC. Finally, we identified a shift in fibro-adipogenic progenitors (FAPs), favoring the CD90 subtype. Mechanistically, conditioned media from patient-derived FAPs reduced myotube width in vitro, uncovering a novel mechanism by which altered paracrine signaling from the muscle resident stromal compartment drives atrophy in cancer cachexia. Interpretation: These findings provide human evidence that altered FAP composition, mitochondrial homeostasis, calcium handling, and immune cell landscape accompany muscle wasting in NSCLC, which may inform therapeutic strategies to preserve skeletal muscle health in patients with cancer.

molecular biology↗