Hub Genes and Immune Cell Infiltration in Hypoxia-Induced Pulmonary Hypertension: Bioinformatics Analysis and In Vivo Validation.

BACKGROUND: Hypoxia-induced pulmonary hypertension (HPH) represents a severe pulmonary disorder with high morbidity and mortality, which necessitates identifying the critical molecular mechanisms underlying HPH pathogenesis. METHODS: The mRNA expression microarray GSE15197 (containing 8 pulmonary tissues from HPH and 13 normal controls) was downloaded from Gene Expression Omnibus (GEO). Gene ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) were executed by RStudio software. The Protein-Protein Interaction (PPI) network was visualized and established using Cytoscape, and the cytoHubba app from Cytoscape was used to pick out the hub modules. The infiltration of immune cells in HPH was analyzed using the CIBERSORTx. To confirm the potential hub genes, real-time quantitative reverse transcription PCR (qRT-PCR) was conducted using lung tissues of rat HPH models and controls. RESULTS: A total of 852 upregulated and 547 downregulated genes were identified. The top terms in biological processes were apoptosis, proliferation, and regulation of the MAPK cascade, including ERK1/2. Cytoplasm, cytosol, and membrane were enriched in cellular component groups. Molecular functions mainly focus on protein binding, protein serine/threonine kinase activity and identical protein binding. KEGG analysis identified pathways in cancer, regulation of actin cytoskeleton and rap1 signaling pathway. There was significantly different immune cell infiltration between HPH and normal control samples. High proportions of the memory subsets of B cells and CD4 cells, Macrophages M2 subtype, and resting Dendritic cells were found in HPH samples, while high proportions of naive CD4 cells and resting mast cells were found in normal control samples. The qRT-PCR results showed that among the ten identified hub modules, FBXL3, FBXL13 and XCL1 mRNA levels were upregulated, while NEDD4L, NPFFR2 and EDN3 were downregulated in HPH rats compared with control rats. CONCLUSION: Our study revealed the key genes and the involvement of immune cell infiltration in HPH, thus providing new insight into the pathogenesis of HPH and potential treatment targets for patients with HPH.

EphrinA3 is a key regulator of malignant behaviors and a potential prognostic factor in lung adenocarcinoma.

BACKGROUND: As a member of the Ephrin protein family that elicits short distance cell-cell signaling, EphrinA3 has been shown to promote or inhibit tumorigenesis depending on tumor types, but its roles and the underlying mechanisms in lung adenocarcinoma (LUAD) have not been reported. MATERIALS AND METHODS: The TCGA database and Kaplan-Meier Plotter database were used to analyze the differential expression of EphrinA3 between LUAD and para-carcinoma tissues, and its effect on overall survival of LUAD patients. CCK-8 assay, Edu assay, and flow cytometry were used to probe the effect of EphrinA3 on the proliferation of LUAD cells, and transwell assay was employed to examine its effect on migration and invasion. In addition, the effect of EphrinA3 on the growth of LUAD was further evaluated using a xenograft tumor model. RESULTS: EphrinA3 was expressed highly in LUAD, and its expression level was negatively correlated with the prognosis of LUAD patients. In addition, EphrinA3 promoted proliferation, migration, and invasion of LUAD cells, and accelerated tumor growth in a xenograft LUAD model. The reported EphrinA3 receptors, EphA1 and EphA10, were expressed in clinical LUAD tissues and co-localized with EphrinA3 in LUAD cells. Mechanistically, EphrinA3/Eph signaling activated AKT, ERK, and p38MAPK, induced epithelial-mesenchymal transition (EMT), and upregulated matrix metalloproteases-2 and -9 (MMP-2/-9). CONCLUSION: EphrinA3 expression was negatively correlated with prognosis of patients with LUAD. EphrinA3 promoted proliferation, migration, and invasion of LUAD cells. EphrinA3 enhanced the phosphorylation of ERK and AKT, and potentiates EMT and MMP expression in LUAD cells.

Protein tyrosine phosphatase PTPL1 suppresses lung cancer through Src/ERK/YAP1 signaling.

BACKGROUND: To reveal the function of protein tyrosine phosphatase-L1 (PTPL1) in lung adenocarcinoma. METHODS: Lung cancer cell lines were transfected with short hairpin RNA against PTPL1 (shPTPL1 group) or negative control (shmock group). Quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting were used to verify the transfection efficacy. Cell proliferation was analyzed by ethynyldeoxyuridine (EdU), Cell counting kit 8 (CCK8), and colony formation assay after PTPL1 or PTPL1 and yes-associated protein (YAP1) knockdown. The effect of PTPL1 on tumor growth was examined in a xenograft lung cancer model. RESULTS: PTPL1 was downregulated in various types of lung cancer cell lines. The EdU, CCK8, colony formation assays and investigation using a xenograft lung cancer model indicated that PTPL1 knockdown increased the proliferation of lung cancer cells. Mechanistically, PTPL1 knockdown induced the activation of the Proto-oncogene tyrosine-protein kinase SRC (Src)/Extracellular regulated MAP kinase (ERK) pathway and thereby promoted yes-associated protein (YAP1) nuclear translocation and activation. CONCLUSIONS: In our study, PTPL1 played a crucial suppressive role in the pathogenesis of lung cancer potentially through counteracting the Src/ERK/YAP1 pathway.

Diagnostic efficiency and safety of rapid on-site evaluation combined with CT-guided transthoracic core needle biopsy in suspected lung cancer patients.

OBJECTIVE: The efficacy of rapid on-site evaluation (ROSE) combined with computed tomography-guided transthoracic core needle biopsy (CT-guided TCNB) is rarely investigated. This study aimed to evaluate the diagnostic efficiency and safety of ROSE combined with CT-guided TCNB for suspected lung cancer patients. MATERIALS AND METHODS: Clinical data from 285 patients who received CT-guided TCNB for suspected lung cancer in Huashan Hospital from 2015 to 2018 were retrospectively analysed. Of these 163 patients underwent CT-guided TCNB combined with ROSE (ROSE group), while the remaining 122 patients underwent without ROSE (non-ROSE group). The smears from TCNB were quickly processed with Diff-Quick staining and analysed by a skilled cytologist on-site. The consistency of ROSE with the final clinicopathological diagnosis and the diagnostic efficiency and safety of ROSE combined with CT-guided TCNB in suspected lung cancer patients were evaluated. RESULTS: ROSE was highly concordant with pathological diagnosis (κ = 0.791; P < 0.001), with an accuracy of 95.7%. Diagnostic accuracy was significantly higher in the ROSE compared with the non-ROSE group (96.3% vs 86.1%; P = 0.002), with overall incidences of complications of 36.8% and 23.8%, respectively. Minor pneumothorax without drainage was slightly greater in the ROSE compared with the non-ROSE group (14.1% vs 6.6%; P = 0.046). However, there was no significant difference in serious complications between the two groups. CONCLUSION: ROSE was highly consistent with the final clinicopathological diagnosis for suspected lung cancer. ROSE further improved the diagnostic efficiency of CT-guided TCNB with no increased incidence of serious complications.

Mxi1-0 Promotes Hypoxic Pulmonary Hypertension Via ERK/c-Myc-dependent Proliferation of Arterial Smooth Muscle Cells.

Background: Hypoxic pulmonary hypertension (HPH) is a challenging lung arterial disorder with remarkably high incidence and mortality, and so far patients have failed to benefit from therapeutics clinically available. Max interacting protein 1-0 (Mxi1-0) is one of the functional isoforms of Mxi1. Although it also binds to Max, Mxi1-0, unlike other Mxi1 isoforms, cannot antagonize the oncoprotein c-Myc because of its unique proline rich domain (PRD). While Mxi1-0 was reported to promote cell proliferation via largely uncharacterized mechanisms, it is unknown whether and how it plays a role in the pathogenesis of HPH. Methods: GEO database was used to screen for genes involved in HPH development, and the candidate players were validated through examination of gene expression in clinical HPH specimens. The effect of candidate gene knockdown or overexpression on cultured pulmonary arterial cells, e.g., pulmonary arterial smooth muscle cells (PASMCs), was then investigated. The signal pathway(s) underlying the regulatory role of the candidate gene in HPH pathogenesis was probed, and the outcome of targeting the aforementioned signaling was evaluated using an HPH rat model. Results: Mxi1 was significantly upregulated in the PASMCs of HPH patients. As the main effector isoform responding to hypoxia, Mxi1-0 functions in HPH to promote PASMCs proliferation. Mechanistically, Mxi1-0 improved the expression of the proto-oncogene c-Myc via activation of the MEK/ERK pathway. Consistently, both a MEK inhibitor, PD98059, and a c-Myc inhibitor, 10058F4, could counteract Mxi1-0-induced PASMCs proliferation. In addition, targeting the MEK/ERK signaling significantly suppressed the development of HPH in rats. Conclusion: Mxi1-0 potentiates HPH pathogenesis through MEK/ERK/c-Myc-mediated proliferation of PASMCs, suggesting its applicability in targeted treatment and prognostic assessment of clinical HPH.