Jian Xu

Background: Pyroptosis is a recently identified form of programmed cell death that plays an important role in cancer initiation and progression. However, the function of pyroptosis in lung adenocarcinoma (LUAD) remains unclear. The study integrated proteomic and single‐cell RNA sequence (scRNA‐seq) data to investigate the potential role of pyroptosis‐related proteins (PRPs) in the tumor microenvironment (TME) and their associations with tumor immunity, prognosis, and therapeutic response. Methods: A comprehensive proteomic analysis was conducted on 103 lung adenocarcinoma patients. We integrated scRNA‐seq data with bioinformatics analyses to evaluate prognostic and immunological characteristics. Unsupervised clustering based on the PRP expression identified three subtypes. We then used gene set enrichment analysis (GSEA) to assess biological functions. We applied TME and CIBERSORT algorithms to analyze immune cell infiltration. Next, we performed functional enrichment, immune infiltration, and cell–cell communication analyses using scRNA‐seq data grouped according to the proteomic subtypes. We constructed a PRP‐related prognostic signature using least absolute shrinkage and selection operator (LASSO)‐Cox regression analysis. Finally, we validated the expression and functional significance of selected proteins by immunohistochemistry, Western blotting, quantitative PCR, and in vitro loss‐of‐function assays. Results: We identified multiple PRPs that correlated with clinicopathologic characteristics, patient prognosis, and immune infiltration patterns in the TME. We further identified three distinct molecular subtypes, including lipid metabolism, signaling transduction, and immune activation. Among these subtypes, the lipid metabolism subtype showed the best prognosis. ScRNA‐seq analysis further supported the immune characteristics of three subtypes and revealed distinct cellular interaction networks and ligand‐receptor pairs. We also established and validated a PRP‐related prognostic score that effectively predicted overall survival in patients with LUAD. In addition, the PRP score was significantly associated with tumor immune status and sensitivity to chemotherapeutic agents. Conclusion: Our integrated analysis of proteomic and scRNA‐seq data demonstrated that PRPs are closely associated with the tumor‐immune‐stromal microenvironment, clinicopathological features, and prognosis in LUAD. These findings improve our understanding of the biological roles of PRPs in LUAD and may provide new strategies for prognostic evaluation and immunotherapy development.

Metastatic pulmonary angiosarcoma exhibits highly heterogeneous clinical, imaging and pathological features, with an extremely poor prognosis. This case report describes a 30‐year‐old woman who presented with recurrent hemoptysis and multiple pulmonary nodules with exudative changes in the lung, pathologically resembling granulomatous lesions and eventually confirmed as primary cardiac angiosarcoma with pulmonary metastasis. Twenty‐two cases of metastatic pulmonary angiosarcoma from the literature were reviewed. For cases with recurrent hemoptysis, multiple pulmonary nodules or thin‐walled cysts and ‘halo sign’ or ground‐glass opacities, metastatic pulmonary angiosarcoma should be highly suspected. Histopathology remains the gold standard for diagnosis. Early biopsies or small biopsy specimens carry a risk of false negativity; adequate tissue samplings are essential to improve diagnostic accuracy.

Background: Lineage tracing is an emerging technology with the outstanding advantage of labeling stem cells and their descendants with temporal and spatial specificity in vivo. We aimed to systematically review the research advances of distal lung epithelial progenitors via lineage tracing strategies. Results: The distal lung, including bronchioles and alveoli, carries the respiratory function and is the central region involved in acute respiratory distress syndrome and other diseases. Many endogenous epithelial stem cell/progenitor lineages such as Club cells, alveolar type II cells, bronchioalveolar stem cells, and basal‐like progenitors that contribute to distal lung regeneration have been identified and are engaged in repairing lung injury for various reasons. Advances in lineage tracing technology have provided tremendous support in characterizing progenitor lineages, identifying new progenitor cell lineages, and discovering regulators of their behaviors. Conclusions: The important role of distal lung epithelial progenitors and lineage tracing methods has been highlighted in recent years. Relevant studies provide a perspective for further deepening lineage tracing in lung progenitor research and laying the groundwork for endogenous stem cell therapies in the future.