Metastasis remains the primary cause of small cell lung cancer (SCLC)-related deaths. Growing evidence links tumor metastasis with a pre-metastatic microenvironment characterized by an anti-inflammatory response, immunosuppression, and the presence of tumor-derived exosomes. To clarify the relationships among these factors in SCLC, we analyzed SCLC patient samples as well as a mouse model. Among the infiltrating immune cells, our study focused on the tumor-associated macrophages (TAMs), that are well-known to promote tumor progression and metastasis. We found that high expression of the alternatively activated (M2) TAM marker, CD206⁺ was associated clinically with a poorer prognosis and metastasis state in patients with SCLC. Moreover, infiltrating macrophages (MØ) were found in the metastatic foci of an SCLC mouse model. Additionally, we observed dominant switching to M2 phenotype, accompanied by increased NLRP6 expression. Since tumor-derived exosomes are the key links between the tumor and its immune microenvironment, we further investigated whether SCLC-derived exosomes contributed to the MØ phenotype switch. Our findings showed for the first time that SCLC-derived exosomes induce the M2 switch via the NLRP6/NF-κB pathway, and thus, promote SCLC metastasis in vitro and in vivo. Collectively, these results indicate a novel mechanism by which SCLC-derived exosomes induce immunosuppression of distant MØ to promote systemic metastasis by activating NLRP6. Here, we highlight the close relationship between the tumor-derived exosomes, inflammasomes and immune microenvironment in SCLC metastasis.

Purpose: Gefitinib, an anticancer drug, has been reported to potentially improve the prognosis of patients with lung adenocarcinoma (LUAD). This study aims to investigate the roles and mechanisms of Gefitinib. Methods: The effects of Gefitinib on the growth and migration of LUAD cells were assessed using various methods, including CCK-8, flow cytometry, wound healing, and Transwell assays. To analyze the function and mechanisms of the differentially expressed Gefitinib target genes (GTGs), data from the TCGA database were utilized. Kaplan-Meier survival and ROC analysis identified prognostic-related GTGs and constructed a prognostic nomogram in LUAD. Consensus clustering, COX analysis and survival analysis evaluated the relationship between GTGs and the prognosis of LUAD patients. The mechanisms of the risk model involved LUAD progression, and the relationship between the risk model and immune microenvironment were investigated. Results: Gefitinib could inhibit proliferation, migration and invasion and promote cell apoptosis. 84 DEGTGs were involved in RAS, MAPK, ERBB pathways. The DEGTGs (FBP1, SBK1, and AURKA) were the independent risk factors for dismal prognosis of LUAD patients and were used to establish risk model and nomogram. Gefitinib could promote the expression of FBP1 and inhibit the expression of SBK1 and AURKA. High-risk LUAD patients had the dismal prognosis, and the high-risk score group was significantly associated with the immune microenvironment. Conclusion: FBP1, SBK1, and AURKA are prognostic risk factors, and the risk model and nomogram of FBP1, SBK1 and AURKA are associated with dismal prognosis and immune cell infiltration, and have huge prospects for application in evaluating the prognosis in LUAD.

Non-small cell lung cancer (NSCLC) constitutes a significant proportion of lung cancer cases, and despite advancements in treatment modalities, radiotherapy resistance remains a substantial hurdle in effective cancer management. Exosomes, which are small vesicles secreted by cells, have emerged as pivotal players in intercellular communication and influence various biological processes, including cancer progression and the response to therapy. This review discusses the intricate role of exosomes in the modulation of NSCLC radiosensitivity. The paper focuses on NSCLC and highlights how tumor-derived exosomes contribute to radioresistance by enhancing DNA repair, modulating immune responses, and altering the tumor microenvironment. We further explore the potential of mesenchymal stem cell-derived exosomes to overcome radiotherapy resistance and their potential as biomarkers for predicting therapeutic outcomes. Understanding the mechanisms by which exosomes affect radiotherapy can provide new avenues for enhancing treatment efficacy and improving the survival rates of patients with NSCLC.