Objective： To investigate the effect and molecular mechanisms of acacetin on migration, invasion and angiogenesis of non-small cell lung cancer (NSCLC) A549 cells. Methods: The effects of various concentrations of acacetin on A549 cell viability were detected by MTT assay and IC50 was calculated. The A549 cells were treated with various concentrations of acacetin, and the relative expression levels of vascular endothelial growth factor (VEGF), Ecadherin and matrix metalloproteinase-9 (MMP-9) were detected by Western blotting. And the ability of cell migration, invasion and angiogenesis was detected by scratch wound healing, Transwell, immunofluorescence and tubulogenesis tests, respectively. VEGF plasmid was overexpressed or knocked down in A549 cells, and the relative expression levels of VEGF, E-cadherin and MMP-9 were detected by Western blotting, and the ability of the migration, invasion and angiogenesis of the cells were further evaluated. Results: Compared with 0 μmol/L group, A549 cell viability in 10, 20, 30, 40 and 50 μmol/L acacetin groups was significantly decreased (P<0.01), and in a certain concentrationdependent manner, IC₅₀ was 34-49 μmol/L. Compared with 0 μmol/L group, the migration, invasion and angiogenesis of A549 cells in 10, 20 and 40 μmol/L acacetin groups were significantly decreased (all P<0.05), and the expression levels of VEGF and MMP-9 protein were significantly decreased (all P<0.01), while the expression level of E-cadherin protein was significantly increased (P<0.01). Compared with blank control or overexpression negative control group, the expression level of MMP-9 protein in A549 cells in overexpression group was significantly increased, while the expression level of E-cadherin protein was significantly decreased, and the ability of cell migration, invasion and angiogenesis was significantly enhanced (all P<0.05). Compared with blank control or knockdown negative control group, the expression level of MMP-9 protein in A549 cells in knockdown group was significantly decreased, while the expression level of E-cadherin protein was significantly increased, and the ability of cell migration, invasion and angiogenesis was significantly decreased (all P<0.05). Conclusion: Acacetin may inhibit migration, invasion and angiogenesis of NSCLC A549 cells by decreasing VEGF expression.

 Objective： To explore the predictive value of systemic immune inflammation index (SII) combined with prealbumin for postoperative pulmonary infection after lung cancer surgery. Methods: A retrospective analysis was performed on 1 025 patients with lung cancer who underwent single lobectomy admitted to the Department of Thoracic Surgery, Affiliated Hospital of Xuzhou Medical University from January 2017 to December 2021. The patients were divided into infected group and non-infected group according to whether they were infected after surgery. The risk factors of postoperative lung infection were analyzed by univariate and multivariate Logistic regression. Receiver operating characteristic (ROC) curve was used to analyze the predictive efficacy of SII and prealbumin alone and in combination for postoperative lung infection. Results: Of the 1 025 patients with lung cancer, 108 cases (10.5%) developed pulmonary infection after surgery. Compared with the non-infected group, the infected group had higher ASA grade, TNM stage, leukocyte level and SII value, more patients with diabetes mellitus, longer operation time and maximum tumor diameter, and lower albumin and prealbumin levels (all P<0.05). Multivariate Logistic regression analysis showed that long operation time, combined diabetes mellitus, low prealbumin level and high SII value were independent risk factors for lung infection after lung cancer surgery (all P<0.05). ROC curve results showed that the area under curve (AUC) of SII was 0.705 (95%CI: 0.656-0.755), and the AUC of prealbumin was 0.626 (95%CI: 0.572-0.680); while the AUC of SII combined with prealbumin in predicting the occurrence of lung infection was 0.751, which was better than the value of single index in the diagnosis and prediction of postoperative lung infection after lung cancer surgery (P<0.05). Conclusion: SII and proalbumin could predict the occurrence of postoperative lung infection after lung cancer surgery, and the combination of SII and proalbumin has higher predictive value for the occurrence of lung infection.
［Key words］lung cancer; systemic immune inflammatory index; prealbumin; postoperative lung infection

 Objective： To investigate the expression level and clinical significance of potassium voltage-gated channel subfamily G member 1 (KCNG1) in human lung cancer tissues, and its role in the malignant biological behavior of lung cancer cells. Methods: The Cancer Genome Atlas (TCGA) database was consulted to explore the expression level of KCNG1 mRNA in human lung cancers, and the relationship between KCNG1 mRNA and clinicopathological features and prognosis of patients with lung cancer; nomogram model was constructed to predict the prognosis of lung cancer patients based on the KCNG1 mRNA expression; Gene Ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis were performed to explore the potential biological functions of KCNG1; gene set enrichment analysis (GSEA) was employed to analyze the differentially expressed genes, through comparing KCNG1 high-expression lung cancer tissues with the KCNG1 low-expression lung cancer tissues retrieved from TCGA database. The expression level of KCNG1 mRNA and protein in lung cancer A549 and H1299 cell lines and normal lung epithelial cells were detected by Western blotting and qRT-PCR assays, respectively. The KCNG1 knockdown cell lines were constructed by transfection of siRNA, and the biological behavior changes of the cell lines were detected by EdU, Transwell, Matrigel Transwell, scratch wound healing and angiogenesis mimicry tests, respectively. Results: The expression of KCNG1 mRNA was significantly upregulated in human lung cancer tissues and was correlated with poor prognosis of lung cancer patients (P<0.05). The nomogram model preliminarily confirmed that KCNG1 may be a potential biomarker of lung cancer and has a good prognostic function. GO and KEGG enrichment analysis suggested that KCNG1 plays an important role in regulating hormone secretion, ion transportation, neuropeptide signaling pathway, and intercellular adhesion. GSEA showed that KCNG1 related differentially expressed genes were enriched in KRAS, MTORC1, MYC, P53, and WNT signaling pathways. The proliferation, migration, invasion and tube formation of si-KCNG1 lung cancer cells were significantly inhibited (P<0.05). Conclusion: The expression of KCNG1 mRNA is significantly overexpressed in lung cancer and is closely related to poor prognosis. SiRNA-mediated knockdown of KCNG1 could significantly inhibit the malignant behaviors of lung cancer cell.
［Key words］lung cancer; potassium voltagegated channel modifier subfamily G member 1; molecular therapeutic target; differentially expressed genes; biomarkers