I invite you to reflect on the significance of acute exercise's impact on the tumor microenvironment (TME). While chronic exercise has been extensively studied for its cancer-preventive properties, the immediate physiological effects of a single exercise session on the TME warrant deeper exploration.
Acute exercise induces transient physiological changes that can modulate the TME and potentially influence tumor development. These changes encompass various physiological pathways:
Tumor Vascularization: A single bout of exercise can enhance tumor blood flow and decrease vascular resistance, leading to improved tumor perfusion. This increased perfusion may alleviate hypoxia within the tumor, a condition often linked to aggressive tumor behavior and resistance to therapy.Immune Modulation: Acute exercise influences immune cell dynamics. For instance, a short exercise session can cause leukocytosis, mobilizing cytotoxic immune cells (e.g., NK cells, T cells) into circulation. This transient increase in immune cells could enhance immune surveillance and the body's ability to target tumor cells.Myokine Secretion: During exercise, skeletal muscles release myokines—cytokines and peptides with autocrine, paracrine, or endocrine effects. Myokines such as IL-6 and irisin may influence tumor progression by modulating angiogenesis, inflammation, and immune responses.Lactate Metabolism: Exercise acutely increases lactate production, which can serve as both an energy substrate and a signaling molecule in the TME. Lactate may modulate tumor metabolism, angiogenesis, and immune function, potentially influencing tumor growth and therapy responses.Catecholamine Surge: Acute exercise triggers the release of catecholamines (e.g., epinephrine, norepinephrine), which can directly affect tumor cells by modulating stress-related pathways. Emerging evidence suggests that catecholamines may enhance immune cell infiltration into tumors, increasing the cytotoxic potential of NK and T cells.Given these insights, it is imperative to further investigate how acute exercise-induced physiological changes can be harnessed to improve cancer therapies and patient outcomes. Understanding the immediate effects of exercise on the TME could lead to novel integrative approaches in cancer treatment.
