Inflammation-based lung adenocarcinoma molecular subtype identification and construction of an inflammation-related signature with bulk and single-cell RNA-seq data.

The role of inflammation is increasingly understood to have a central influence on therapeutic outcomes and prognosis in lung adenocarcinoma (LUAD). However, the detailed molecular divisions involved in inflammatory responses are yet to be fully elucidated. Our study identified two main inflammation-oriented LUAD grades: the inflammation-low (INF-low) and the inflammation-high (INF-high) subtypes. Both presented with unique clinicopathological features, implications for prognosis, and distinctive tumor microenvironment profiles. Broadly, the INF-low grade, marked by its dominant immunosuppressive tumor microenvironment, was accompanied by less favorable prognostic outcomes and a heightened prevalence of oncogenic mutations. In contrast, the INF-high grade exhibited more optimistic clinical trajectories, underscored by its immune-active environment. In addition, our efforts led to the conceptualization and empirical validation of an inflammation-centric predictive model with considerable predictive potency. Our study paves the way for a refined inflammation-centric LUAD classification and fosters a deeper understanding of tumor microenvironment intricacies.

Lymph node metastasis and its risk factors in T1 lung adenocarcinoma.

BACKGROUND: In this study, the focus was primarily on examining the occurrence of lymph node metastasis in T1 lung adenocarcinoma, while also analyzing the relationship between clinical variables such as imaging characteristics, pathological classifications, and lymph node metastasis. METHODS: We retrospectively analyzed data from patients with T1 lung adenocarcinoma who underwent lobectomy and lymph node dissection between January 2016 and December 2019. Utilizing univariate and multivariate analyses, we assessed the associations between lymph node metastasis and various clinical factors, including imaging characteristics, lesion location and depth, and pathological subtypes. RESULTS: Of the 433 patients with T1 lung adenocarcinoma, 139 had lymph node metastasis. Moreover, the incidence of node 1 (N1) lymph node, sequential, and node 2 (N2) skip metastases were 12.2%, 12.7%, and 7.2%, respectively. Univariate analysis revealed that tumor diameter, depth ratio, sex, invasive imaging features, and pathological subtype were significantly associated with lymph node metastasis. Multivariate analysis revealed that the tumor depth ratio, tumor diameter, pleural indentation or traction sign, nonvascular penetration sign, solid component, nonadherence, and micropapillary pathological subtype were risk factors for lymph node metastasis. In the multivariate analysis, the micropapillary pathological subtype was an independent risk factor for N2 skip metastasis. CONCLUSIONS: In patients with clinical stage T1 lung adenocarcinoma, the risk of lymph node metastasis is higher for tumors located deep within the lung tissue with solid components, invasive preoperative imaging features, and larger diameters. For N2 skip lymph node metastasis, the micropapillary pathological subtype represents a significant high-risk factor.

Tumor-derived exosomal HOTAIRM1 regulates SPON2 in CAFs to promote progression of lung adenocarcinoma.

OBJECTIVE: SPON2 is one of the extracellular matrix proteins, which is closely related to the progression of a variety of tumors including non-small cell lung cancer (NSCLC), but its upstream regulation mechanism remains unclear. Our research aims to find the specific regulatory pathway of SPON2 by exploring the potential crosstalk between tumor cells and cancer-associated fibroblasts (CAFs) in tumor microenvironment (TME) of NSCLC. METHODS: We analyzed T1 lung adenocarcinoma samples from TCGA and screened extracellular matrix proteins that indicate poor prognosis. Expression level of SPON2 was verified by qPCR in clinical samples. The exosomes of NSCLC cell supernatant were extracted and identified by nanoparticle tracking analysis (NTA) and transmission electron microscope, western blots. The exosomes and CAFs were co-cultured, and cell migration and Matrigel invasion assay were used to evaluate the effect of CAFs on the migration and invasion of NSCLC cells. The interaction between LncRNA and miRNA was verified by Targetscan prediction, luciferase reporter assay, and RNA binding protein immunoprecipitation (RIP). RESULTS: We found that the expression of SPON2 was up-regulated in clinical T1a stage NSCLC patients. The expression of lnc HOTAIRM1 (HOTAIRM1) in exosomes secreted by NSCLC tissues increased. After exosomal HOTAIRM1 entered CAFs, HOTAIRM1 can adsorb miR-328-5p to up-regulate the expression of SPON2 in CAFs. Up-regulation of SPON2 in CAFs could promote the migration and invasion of NSCLC cells. CONCLUSION: Tumor-derived exosomal HOTAIRM1 can transfer into CAFs and competitively adsorb miR-328-5p, and regulate the SPON2 expression of CAFs cells, ultimately promote the progression of NSCLC. The discovery of this regulatory pathway can provide a new potential therapeutic target for the diagnosis and treatment of NSCLC.

A novel glycosyltransferase-related lncRNA signature correlates with lung adenocarcinoma prognosis.

Background: Lung adenocarcinoma (LUAD) is one of the most fatal cancers in the world. Previous studies have shown the increase in glycosylation level, and abnormal expressions of related enzymes are closely related to various cancers. Long non-coding RNAs (lncRNAs) play an important role in the proliferation, metabolism, and migration of cancer cells, but the underlying role of glycosyltransferase (GT)-related lncRNAs in LUAD remains to be elucidated. Methods: We abstracted 14,056 lncRNAs from The Cancer Genome Atlas (TCGA) dataset and 257 GT-related genes from the Gene Set Enrichment Analysis (GSEA) database. Univariate, LASSO-penalized, and multivariate Cox regression analyses were conducted to construct a GT-related lncRNA prognosis model. Results: A total of 2,726 GT-related lncRNAs were identified through Pearson's correlation analysis, and eight of them were utilized to construct a GT-related lncRNA model. The overall survival (OS) of the low-risk group continued to be superior to that of the high-risk group according to the subgroups classified by clinical features. The risk model was proved to have independent prognostic characteristics for LUAD by univariate and multivariate Cox regression analyses. The status of the tumor immune microenvironment and the relevant immunotherapy response was significantly different between the two risk groups. The candidate drugs aimed at LUAD subtype differentiation were identified. Conclusion: We constructed a risk model comprising eight GT-related lncRNAs which was identified as an independent predictor of prognoses to predict patient survival and guide-related treatments for patients with LUAD.

Partitioning the lung field based on the depth ratio in three-dimensional space.

Background: To explore the feasibility of the depth ratio method partitioning the lung parenchyma and the depth distribution of lung nodules in pulmonary segmentectomy. Methods: Based on the measurement units, patients were allocated to the chest group, the lobar group, and the symmetrical 3 sectors group. In each unit, the center of the respective bronchial cross-section was set as the starting point (O). Connecting the O point with the center of the lesion (A) and extending to the endpoint (B) on the pleural, the radial line (OB) was trisected to divide the outer, middle, and inner regions. The depth ratio and relevant regional distribution were simultaneously verified using 2-dimensional (2D) coronal, sagittal, and axial computed tomography images and 3-dimensional (3D) reconstruction images. Results: Two hundred and nine patients were included in this study. The median age was 53 (IQR, 44.5-62) years and 64 were males. The intra-group consistency of the depth ratio region partition was 100%. The consistency of the inter-group region partition differed among the three groups (Kappa values 0.511, 0.517, and 0.923). The chest group, lobar group, and symmetrical 3 sectors group had 69.4%, 26.3%, and 4.8% mediastinum disturbance, respectively (P<0.001). Conclusions: The depth ratio method in the symmetrical 3 sectors of the lung maximally eliminated the disturbance of the mediastinal structures and more accurately trisected the lung parenchymal in 3D space. Sublobar resection based on subsegments strategy is feasible for outer 2/3 pulmonary nodules when depth ratio is used as the measurement method.

A modified system for classifying the bilateral superior pulmonary veins using three-dimensional computed tomography bronchography and angiography images.

BACKGROUND: Identifying the distribution of pulmonary veins with three-dimensional reconstruction images is of great significance for surgical guidance. Existing models neglect the consistency of the bilateral superior pulmonary veins (SPVs) and lack a simple unified classification pattern. This study aimed to analyze the distributional features of bilateral SPVs, based on a cohort of patients undergoing CT examination. METHODS: The three-dimensional computed tomography bronchography and angiography (3D-CTBA) images of 1,520 cases were retrospectively analyzed. The reconstructed images of the right upper lobes were read in 715 cases, and left upper lobes in 805 cases. Through symmetrical analysis, the circulation of main venous branches and the spatial relationships of confluences with adjacent bronchus were compared. RESULTS: The SPVs of bilateral upper lobes showed common distributional features and were divided into three main types. The central vein type, the semi-central vein type, and the non-central vein type accounted for 83.35% [596], 7.84% [56], 8.11% [58] of the 715 cases with right scanning, and 25.71% [207], 62.61% [504], 10.81% [87] of the 805 cases with left scanning, respectively. There were 5 (0.70%) cases with rare variations in the right upper lobe and 7 (0.87%) in the left upper lobe. The attribution of intersubsegmental vein in the posterior segment (V2b) and its position relative to the anterior segmental bronchus (B3) was the basis of classification in the right upper lobe, and the attribution of intersubsegmental vein in the apicoposterior segment (V1+2c) and its position relative to B3 was the basis of classification in the left upper lobe. In this classification system, the branching pattern of the intersegmental vein between the apical segment and the anterior segment (V1b) in the right upper lobe, and the intersegmental vein between the apicoposterior segment and the anterior segment (V1+ 2a) in the left upper lobe were used for subdivision. CONCLUSIONS: Our modified system had a high degree of consistency in classifying SPVs in bilateral upper lobes, thus providing guidance for preoperative and intraoperative procedures.

Tumor-associated macrophages secret exosomal miR-155 and miR-196a-5p to promote metastasis of non-small-cell lung cancer.

BACKGROUND: Understanding the molecular basis underlying metastasis of non-small cell lung cancer (NSCLC) may provide a new therapeutic modality for the treatment of NSCLC. However, the mechanisms by which tumor-associated macrophages (TAMs) affect NSCLC metastasis remain undefined. In this study, we aimed to discover a novel regulatory pathway involved in NSCLC metastasis. METHODS: Cell Counting Kit-8 (CCK-8), Transwell, western blot assays were used to assess cell viability, migration, invasion and epithelial-mesenchymal transition (EMT). Exosomes from macrophages medium were characterized, and in vitro cell coculture was further conducted to investigate M2 derived exosomes mediated crosstalk between TAMs and tumor cells. Besides, miRNA microarray was used to analyze miRNA expression profiles of M0 and M2 derived exosomes. Luciferase reporter assay was used to verify the potential binding between miRNA and mRNA. Moreover, 6-week-old male BALB/c nude mice were performed to establish transplantation tumor model using tail vein injection. Hematoxylin & eosin staining was used to detect the metastasis of tumor tissues. RESULTS: We found that M2 TAMs were the main TAMs in metastatic tissues of NSCLC patients and exosomes derived from M2 TAMs were able to promote cell viability, cell migration, cell invasion and EMT in NSCLC. We demonstrated that miR-155 and miR-196a-5p were abundant in M2 TAMs and exosomes secreted by M2 TAMs. Functional experiments demonstrated that the deletion of miR-155 and miR-196a-5p in M2 TAMs significantly prevented NSCLC metastasis in vitro and in vivo. To clarify the mechanism governing miR-155 and miR-196a-5p from M2 TAMs, we carried out bioinformatics analysis to predict potential target genes. Mechanistically, miR-155 and miR-196a-5p directly bound to the 3'-UTR of Ras association domain family member 4 (RASSF4), and negatively regulating RASSF4 expression. At last, rescue assays demonstrated that miR-155 and miR-196a-5p exerted its performance by RASSF4. CONCLUSIONS: Overall, we revealed a new regulatory pathway that was M2 TAMs secreted exosomal miR-155 and miR-196a-5p to promote NSCLC metastasis. This dynamic and reciprocal cross-talk between NSCLC and macrophages innovatively provided a potential opportunity for diagnosis and treatment of NSCLC.