Tumor hypoxia shapes natural killer cell anticancer activities

Area of Science:

• Immunology
• Oncology
• Cancer Biology

Background:

• Tumor hypoxia is a critical factor in the tumor microenvironment (TME).
• Hypoxia significantly impairs natural killer (NK) cell antitumor functions.
• NK cells are crucial for cancer immunosurveillance and immunotherapy efficacy.

Purpose of the Study:

• To comprehensively review the mechanisms by which tumor hypoxia suppresses NK cell activity.
• To highlight molecular pathways and cellular adaptations involved in NK cell evasion by cancer cells.
• To discuss emerging strategies for overcoming hypoxia-induced immunosuppression to enhance cancer immunotherapy.

Main Methods:

• Literature review of studies on tumor hypoxia and NK cell function.
• Analysis of molecular and cellular mechanisms linking hypoxia to impaired NK cell cytotoxicity.
• Synthesis of current and emerging therapeutic strategies targeting the hypoxic TME.

Main Results:

• Hypoxia stabilizes hypoxia-inducible factors, promotes metabolic reprogramming, angiogenesis, and cancer stemness.
• Hypoxia induces immunosuppressive molecules and phenotypic/functional changes in cancer and NK cells.
• These adaptations lead to tumor progression and resistance to immunotherapy.

Conclusions:

• Targeting hypoxia-induced immunosuppression is essential for improving cancer immunotherapy.
• Strategies like nanotechnology, cytokine preconditioning, and vascular normalization show promise.
• Enhancing NK cell functionality in the hypoxic TME can synergize with existing cancer therapies for better outcomes.