From bench to bedside: Exploring the role of sCD25 in melanoma and lung cancer among sleep apnea patients.

[INTRODUCTION AND OBJECTIVES] The study examines how hypoxaemia in obstructive sleep apnoea (OSA) relates to cancer. It focuses on CD25, an immune-checkpoint, analyzing its levels in OSA patients with and without cancer to assess whether CD25 could serve as a biomarker for cancer mortality.

[MATERIALS AND METHODS] We investigated the plasma levels of soluble CD25 (sCD25) in three independent cohorts: patients with no evidence of cancer, with melanoma, and with lung cancer. We explored the role of hypoxaemia by intermittent hypoxia (IH) and HIF-1α inhibition models.

[RESULTS] Our results suggest that sCD25 increases with hypoxemia severity in OSA, both with or without cancer. OSA patients also exhibit early upregulation of membrane-bound CD25 in T lymphocytes. Our findings corroborate that IH, via HIF-1α, mediates the upregulation of both membrane-bound and sCD25. sCD25 levels correlate with markers of melanoma and lung cancer aggressiveness, and elevated sCD25 levels are associated with higher lung cancer mortality risk.

[CONCLUSION] Our study indicates that hypoxia mediates the increase of CD25 in OSA patients. In turn, our data revealed sCD25 were related to tumour aggressiveness in OSA patients with melanoma or lung cancer, and suggest sCD25 as a potential novel biomarker to stratify OSA patients with lung cancer by mortality risk.