Melittin induces ferroptosis and ER stress-CHOP-mediated apoptosis in A549 cells.

Melittin is a natural polypeptide present in bee venom, with significant anti-tumor activity. Melittin has been reported to induce cell death in lung carcinoma cell line A549 cells, suggesting an excellent potential for treating lung cancer. However, the core mechanism underlying melittin-induced cell death in A549 cells remains unclear. This work reports that melittin induces reactive oxygen species (ROS) burst, upregulates intracellular Fe2+ levels, disrupts the glutathione-glutathione peroxidase 4 antioxidant system, and increases lipid peroxide accumulation, eventually inducing cell death, indicating that ferroptosis may be involved in the antitumor effects of melittin in A549 cells. Furthermore, A549 cells treated with the ferroptosis inhibitors ferrostatin-1 and deferoxamine demonstrated that these inhibitors could reverse the cell death induced by melittin, further confirming that melittin induces A549 cell death via ferroptosis. Furthermore, the results also illustrated that melittin activated the endoplasmic reticulum (ER) stress-CHOP (C/EBP homologous protein) apoptotic signal, closely associated with high-level intracellular ROS. The ER stress inhibitor, 4-Phenylbutyric acid, was used to confirm that ER stress-CHOP apoptotic signaling is another molecular mechanism of melittin-induced A549 cell death. Thus, our results demonstrate that ferroptosis and ER stress-CHOP signaling are key molecular mechanisms of melittin-induced cell death in lung cancer.KEY POLICY HIGHLIGHTSMelittin upregulates intracellular Fe2+ levels, leading to the accumulation of lipid peroxides in A549 cells.Melittin disrupts the glutathione-glutathione peroxidase 4 antioxidant system in A549 cells.Melittin induces activation of endoplasmic reticulum stress-C/EBP homologous protein apoptosis signal.Ferroptosis and ER stress are the core molecular mechanisms underlying melittin-induced cell death in A549 cells.

DUS4L Silencing Suppresses Cell Proliferation and Promotes Apoptosis in Human Lung Adenocarcinoma Cell Line A549.

PURPOSE: This study aims to investigate the potential role of DUS4L (dihydrouridine synthase 4 like) in lung adenocarcinoma (LUAD) and explore its associated pathways in human LUAD. METHODS: Firstly, we evaluated the relationships between clinicopathological characteristics and DUS4L expression via analysis of TCGA RNA sequencing data and other publicly available databases. Then, DUS4L was effectively silenced in LUAD cell line A549 using the lentiviral shRNA (short-hairpin RNA) transfection to assess its effects on cell proliferation, cycle and apoptosis in LUAD cells. RNA-seq technology was applied to shDUS4L and shCtrl-transfected cells to generate the corresponding gene expression profiles. Differentially expressed genes (DEGs) were identified using the DESeq2 program package. Also, DEGs were subjected to Gene Ontology (GO) and KEGG (Kyoto Encyclopedia of Genes and Genomes) enrichment analysis to explore the associated molecular signaling pathways and relevant biological functions. RESULTS: Analysis of TCGA data revealed that DUS4L was highly upregulated in LUAD tissues which was related to clinical T and TNM stages of LUAD. The knockdown of DUS4L effectively inhibited cell proliferation and promoted apoptosis in A549 cells. Furthermore, the DEGs between the shDUS4L and shCtrl A549 cells were mainly enriched in biological processes associated with spliceosome, ribosome, RNA catabolic process, ncRNA (non-coding RNA) processing, and p53 signaling pathway. CONCLUSION: Altogether, our results suggest that DUS4L is significantly associated with tumorigenesis and could be utilized as a novel biomarker and therapeutic target for LUAD.

Expressions of CXCL13, CD10 and bcl-6 in angioimmunoblastic T-cell lymphoma and peripheral T-cell lymphoma, not otherwise specified / 中华病理学杂志

<p><b>OBJECTIVE</b>To study the value of immunomarkers CXCL13, CD10, bcl-6 in pathologic diagnosis of angioimmunoblastic T-cell lymphoma (AITL).</p><p><b>METHODS</b>One hundred and fifteen cases of AITL, 30 cases of peripheral T-cell lymphoma, not otherwise specified (PTCL, NOS) and 30 cases of reactive lymph nodes with paracortical hyperplasia (RH) encountered during the period from January, 1990 to January, 2008 were retrieved from the archival files of the Department of Pathology, West China Hospital of Sichuan University, China. The morphologic features were reviewed and compared. Immunohistochemical study was performed by SP method for CXCL13, CD10, bcl-6, CD21, CD3epsilon, CD3, CD45RO, CD20 and Ki-67. TCR-gamma gene rearrangement study was also carried out.</p><p><b>RESULTS</b>Regressed follicles were evident in 7.8% (9/115) of AITL cases, 6.7% (2/30) of PTCL, NOS cases and 83.3% (25/30) of RH cases, respectively. A marked increase of number of arborizing venules was shown in 98.3% (113/115) of AITL cases, 63.3% (19/30) of PTCL, NOS cases and 76.7% (23/30) of RH cases, respectively. In lymph nodes with paracortical hyperplasia, the expression of CXCL13, CD10 and bcl-6 were restricted to the germinal centers. In AITL, 96.5% (111/115) of cases showed CXCL13 expression, in contrast to 26.7% (8/30) of PTCL, NOS. Expression of CD10 and bcl-6 were found in the neoplastic cells in 50.4% (58/115) and 78.3% (90/115) of AITL, and 3.3% (1/30) and 3.3% (1/30) of PTCL, NOS, respectively. Irregular meshworks of CD21-positive follicular dendritic cells were found in all the AITL cases. Clonal TCR-gamma rearrangement was detected in 83% (83/100) of the AITL cases.</p><p><b>CONCLUSIONS</b>AITL is a type of lymphoma originated from the follicular helper T cells. Detailed morphologic assessment and use of immunohistochemical markers are essential for accurate diagnosis.</p>