Chronic exposure to indoor biomass smoke from the combustion of solid organic fuels is a major cause of disease burden worldwide. Almost 3 billion people use solid fuels such as wood, charcoal, and crop residues for indoor cooking and heating, accounting for approximately 50% of all households and 90% of rural households globally. Biomass smoke contains many hazardous pollutants, resulting in household air pollution (HAP) exposure that often exceeds international standards. Long-term biomass-smoke exposure is associated with Chronic Obstructive Pulmonary Disease (COPD) in adults, a leading cause of morbidity and mortality worldwide, chronic bronchitis, and other lung conditions. Biomass smoke-associated COPD differs from the best-known cigarette smoke-induced COPD in several aspects, such as a slower decline in lung function, greater airway involvement, and less emphysema, which suggests a different phenotype and pathophysiology. Despite the high burden of biomass-associated COPD, the molecular, genetic, and epigenetic mechanisms underlying its pathogenesis are poorly understood. This review describes the pathogenic mechanisms potentially involved in lung damage, the development of COPD associated with wood-derived smoke exposure, and the influence of genetic and epigenetic factors on the development of this disease.

Natural killer (NK) cells have the dual ability to produce pro-inflammatory (IFNγ) and anti-inflammatory (IL-10) cytokines during systemic infection, which points to their crucial role both as inflammatory effectors for infection clearance and as regulators to counterbalance inflammation to limit immune-mediated damage to the host. In particular, immunosuppressive IL-10 secretion by NK cells has been described to occur in systemic, but not local, infections as a recent immunoregulatory mechanism of inflammation that may be detrimental or beneficial, depending on the timing of release, type of disease, or the infection model. Understanding the factors that drive the production of IL-10 by NK cells and their impact during dualistic inflammatory states, such as sepsis and other non-controlled inflammatory diseases, is relevant for achieving effective therapeutic advancements. In this review, the evidence regarding the immunoregulatory role of IL-10-producing NK cells in systemic infection is summarized and discussed in detail, and the potential molecular mechanisms that drive IL-10 production by NK cells are considered.

The high mortality from lung cancer is mainly attributed to the presence of metastases at the time of diagnosis. Despite being the leading cause of lung cancer death, the underlying molecular mechanisms driving metastasis progression are still not fully understood. Recent studies suggest that tumor cell exosomes play a significant role in tumor progression through intercellular communication between tumor cells, the microenvironment, and distant organs. Furthermore, evidence shows that exosomes release biologically active components to distant sites and organs, which direct metastasis by preparing metastatic pre-niche and stimulating tumorigenesis. As a result, identifying the active components of exosome cargo has become a critical area of research in recent years. Among these components are microRNAs, which are associated with tumor progression and metastasis in lung cancer. Although research into exosome-derived microRNA (exosomal miRNAs) is still in its early stages, it holds promise as a potential target for lung cancer therapy. Understanding how exosomal microRNAs promote metastasis will provide evidence for developing new targeted treatments. This review summarizes current research on exosomal miRNAs’ role in metastasis progression mechanisms, focusing on lung cancer.

Exosome-derived microRNAs (miRNAs) are potential biomarkers for lung cancer detection and monitoring through liquid biopsy. These small, non-coding RNA molecules are found within exosomes, which are extracellular vesicles released from cells. Their stability in biofluids, such as blood, positions them as candidates for minimally invasive diagnostics. Multiple studies have shown that lung cancer patients exhibit distinct miRNA profiles compared to healthy individuals. This finding suggests that exosome-derived miRNAs could serve as valuable biomarkers for diagnosis, prognosis, and evaluating therapeutic responses. This review summarizes recent research on exosome-derived miRNAs in liquid biopsies, including blood, pleural effusion, and pleural lavage, as biomarkers for lung cancer, focusing on publications from the last five years.

Brain metastasis is a significant clinical challenge for patients with advanced lung cancer, occurring in about 20–40% of cases. Brain metastasis causes severe neurological symptoms, leading to a poor prognosis and contributing significantly to lung cancer-related mortality. However, the underlying molecular mechanism behind brain metastasis remains largely unknown. MicroRNAs (miRNAs) are small, non-coding RNAs linked to several aspects of cancer progression, including metastasis. In the context of lung cancer, significant research has shown the involvement of miRNAs in regulating critical pathways related to metastatic spread to the brain. This review summarizes the scientific evidence regarding the regulatory roles of intra- and extracellular miRNAs, which specifically drive the spread of lung cancer cells to the brain. It also revises the known molecular mechanisms of brain metastasis, focusing on those from lung cancer as the primary tumor to better understand the complex mechanisms underlying this regulation. Understanding these complex regulatory mechanisms holds promise for developing novel diagnostic biomarkers and potential therapeutic strategies in brain metastasis.

Lung cancer remains the cancer with the highest mortality worldwide, largely due to a limited understanding of the precise molecular mechanisms that drive its progression. microRNAs (miRNAs) have emerged as crucial regulators of lung cancer progression by influencing key cellular processes, notably the epithelial–mesenchymal transition (EMT). EMT is a complex and potentially reversible process where epithelial cells lose their polarity and adhesion, reorganize their cytoskeleton, and transition to a mesenchymal phenotype, enhancing their migratory and invasive capacities. While EMT plays an essential role in normal physiological contexts such as tissue development and wound healing, it is also a critical mechanism underlying the progression and metastasis of lung cancer. This review aims to summarize the latest research findings on the role of endogenous and exosome-derived microRNAs in regulating EMT in lung cancer, focusing on studies conducted over the past five years. It also provides an overview of EMT’s essential molecular mechanisms to better understand how miRNAs regulate EMT in lung cancer.