Mechanotransduction Failure and Molecular Rescue in Gastric Cancer: Kinetotherapy Across the IL-6/STAT3–Myostatin/ACVR2B–Akt/mTOR Axis

Muscle wasting associated with gastric cancer represents a complex, multifactorial systems disorder involving inflammatory, anabolic, mechanosensory, calcium-regulatory, mitochondrial, and proteostatic disruption. This review synthesizes current evidence regarding the cellular and physiological mechanisms involved in skeletal muscle dysfunction in gastric cancer and provides a unifying framework centered on loss of signaling coherence. Specifically, it examines IL-6/STAT3 and NF-κB inflammatory signaling, the myostatin–activin–ACVR2B–SMAD pathway, PI3K/Akt/mTOR signaling, mechanotransduction, excitation–metabolism coupling, calcium homeostasis, mitochondrial function, and proteostasis. Although individual components of these pathways have been implicated in muscle wasting associated with chronic disease, current evidence suggests that they interact through positive feedback loops. Inflammation, anabolic resistance, impaired force-to-signal conversion, mitochondrial stress, altered intracellular calcium homeostasis, and disrupted protein quality control may reinforce one another, contributing to metabolic, structural, and transcriptional instability. Within this context, muscle wasting reflects not only loss of muscle mass or strength, but also loss of functional integrity resulting from disrupted integration of mechanical, metabolic, inflammatory, and anabolic signals. Given the systemic nature of these effects, this review proposes kinesitherapy as a potentially useful nonpharmacological adjunctive strategy that may modulate inflammation, restore responsiveness to mechanical stimuli, support calcium homeostasis and mitochondrial function, improve anabolic sensitivity, and maintain protein quality control. Overall, this review presents a systems-biology model of gastric cancer-associated muscle wasting and supports further investigation of exercise-based therapies for this condition.