Whispers in the Lungs: Small Extracellular Vesicles in Lung Cancer and COPD Crosstalk

Lung cancer is one of the deadliest forms of cancer. Its prognosis becomes even worse when it co-occurs with other diseases, such as chronic obstructive pulmonary disease (COPD). Both illnesses have numerous shared risk factors, including the use of tobacco smoke, and have similar underlying mechanisms like long-term inflammation. There are some other less studied but equally important molecules, like small extracellular vesicles (sEVs), that have been shown to mediate effective communication at the cellular level and may affect the progression of a disease or cause resistance to therapies. In sEVs from lung cancer tumors, there are onco-proteins (e.g., tumor initiator EGFR mutations, onco-miR, miR-21), while in sEVs from patients with COPD, there are pro-inflammatory cytokines like IL-6 and TNF-alpha that enhance airway inflammation. These potential biomarkers of sEVs from chronic lung disease have great value in defense against emerging health problems; however, limitations in sample extraction and analysis are obstacles that hinder clinical enhanced applicability. This review focuses on sEV-derived biomarkers in lung cancer and COPD for diagnostic, prognostic, and therapeutic monitoring purposes. To make these molecules more useful in real-life therapy and determine their signature's role, further investigation with a high-scale study is necessary.