Promotion of ROS-mediated apoptosis, G2/M arrest, and autophagy by naringenin in non-small cell lung cancer.

Background: As lung cancer is the leading cause of cancer death worldwide, the development of new medicines is a crucial endeavor. Naringenin, a flavanone derivative, possesses anti-cancer and anti-inflammatory properties and has been reported to have cytotoxic effects on various cancer cells. The current study investigated the underlying molecular mechanism by which naringenin induces cell death in lung cancer. Methods: The expression of apoptosis, cell cycle arrest, and autophagy markers in H1299 and A459 lung cancer cells was evaluated using a terminal deoxynucleotidyl transferase dUTP nick end labeling assay (TUNEL), Western blot, Annexin V/PI stain, PI stain, acridine orange staining, and transmission electron microscopy (TEM). Using fluorescence microscopy, DALGreen was used to observe the degradation of p62, a GFP-LC3 plasmid was used to evaluate puncta formation, and a pcDNA3-GFP-LC3-RFP-LC3ΔG plasmid was used to evaluate autophagy flux. Furthermore, the anti-cancer effect of naringenin was evaluated in a subcutaneous H1299 cell xenograft model. Results: Naringenin treatment of lung cancer cells (H1299 and A459) reduced cell viability and induced cell cycle arrest. Pretreatment of cells with ROS scavengers (N-acetylcysteine or catalase) suppressed the naringenin-induced cleavage of apoptotic protein and restored cyclin-dependent kinase activity. Naringenin also triggered autophagy by mediating ROS generation, thereby activating AMP-activated protein kinase (AMPK) signaling. ROS inhibition not only inhibited naringenin-induced autophagic puncta formation but also decreased the ratio of microtubule-associated proteins 1A/1B light chain 3 II (LC3II)/LC3I and activity of the AMPK signaling pathway. Furthermore, naringenin suppressed tumor growth and promoted apoptosis in the xenograft mouse model. Conclusion: This study demonstrated the potent anti-cancer effects of naringenin on lung cancer cells, thereby providing valuable insights for developing small-molecule drugs that can induce cell cycle arrest, apoptosis, and autophagic cell death.

CXCL14 promotes metastasis of non-small cell lung cancer through ACKR2-depended signaling pathway.

Background: Lung cancer is a malignant tumor with metastatic potential. Chemokine ligand 14 (CXCL14) has been reported to be associated with different cancer cell migration and invasion. However, few studies have explored the function of CXCL14 and its specific receptor in lung cancer metastasis. This study aims to determine the mechanism of CXCL14-promoted cancer metastasis. Methods: The expression of CXCL14, atypical chemokine receptor 2 (ACKR2), and epithelial mesenchymal transition (EMT) markers was evaluated by the public database of The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO), Western blot, enzyme-linked immunosorbent assay (ELISA), quantitative real-time polymerase chain reaction (qPCR), immunohistochemistry (IHC), and immunofluorescence (IF). Migration and wound healing assays were used to observe the motility of cancer cells. A luciferase reporter assay was performed to analyze transcription factor activity. The metastasis of lung cancer cells was evaluated in an orthotopic model. Results: We have presented that overexpression of CXCL14 and ACKR2 was observed in lung cancer datasets, human lung tumor sections, and lung cancer cells. Furthermore, the migration of CXCL14-promoted lung cancer cells was determined in vitro and in vivo. In particular, ACKR2 knockdown abolished CXCL14-induced cancer cell motility. Additionally, ACKR2 was involved in CXCL14-triggered phospholipase Cß3 (PLCß3), protein kinase Cα (PKCα), and proto-oncogene c-Src signaling pathway and subsequently upregulated nuclear factor κB (NF-κB) transcription activity leading to EMT and migration of lung cancer cells. These results indicated that the CXCL14/ACKR2 axis played an important role in lung cancer metastasis. Conclusion: This study is the first to reveal the function of CXCL14 in promoting EMT and metastasis in lung cancer. As a specific receptor for CXCL14 in lung cancer, ACKR2 mediates CXCL14-induced signaling that leads to cell motility. Our findings can be used as a prognostic biomarker of lung cancer metastasis.

Naringenin Induces ROS-Mediated ER Stress, Autophagy, and Apoptosis in Human Osteosarcoma Cell Lines.

Osteosarcoma, a primary bone tumor, responds poorly to chemotherapy and radiation therapy in children and young adults; hence, as the basis for an alternative treatment, this study investigated the cytotoxic and antiproliferative effects of naringenin on osteosarcoma cell lines, HOS and U2OS, by using cell counting kit-8 and colony formation assays. DNA fragmentation and the increase in the G2/M phase in HOS and U2OS cells upon treatment with various naringenin concentrations were determined by using the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay and Annexin V/propidium iodide double staining, respectively. Flow cytometry was performed, and 2',7'-dichlorodihydrofluorescein diacetate, JC-1, and Fluo-4 AM ester probes were examined for reactive oxygen species (ROS) generation, mitochondrial membrane potential, and intracellular calcium levels, respectively. Caspase activation, cell cycle, cytosolic and mitochondrial, and autophagy-related proteins were determined using western blotting. The results indicated that naringenin significantly inhibited viability and proliferation of osteosarcoma cells in a dose-dependent manner. In addition, naringenin induced cell cycle arrest in osteosarcoma cells by inhibiting cyclin B1 and cyclin-dependent kinase 1 expression and upregulating p21 expression. Furthermore, naringenin significantly inhibited the growth of osteosarcoma cells by increasing the intracellular ROS level. Naringenin induced endoplasmic reticulum (ER) stress-mediated apoptosis through the upregulation of ER stress markers, GRP78 and GRP94. Naringenin caused acidic vesicular organelle formation and increased autophagolysosomes, microtubule-associated protein-light chain 3-II protein levels, and autophagy. The findings suggest that the induction of cell apoptosis, cell cycle arrest, and autophagy by naringenin through mitochondrial dysfunction, ROS production, and ER stress signaling pathways contribute to the antiproliferative effect of naringenin on osteosarcoma cells.

A Role of CXCL1 Drives Osteosarcoma Lung Metastasis via VCAM-1 Production.

Osteosarcoma, a common aggressive and malignant cancer, appears in the musculoskeletal system among young adults. The major cause of mortality in osteosarcoma was the recurrence of lung metastases. However, the molecular mechanisms of metastasis involved in osteosarcomas remain unclear. Recently, CXCL1 and CXCR2 have been crucial indicators for lung metastasis in osteosarcoma by paracrine releases, suggesting the involvement of directing neutrophils into tumor microenvironment. In this study, overexpression of CXCL1 has a positive correlation with the migratory and invasive activities in osteosarcoma cell lines. Furthermore, the signaling pathway, CXCR2/FAK/PI3K/Akt, is activated through CXCL1 by promoting vascular cell adhesion molecule 1 (VCAM-1) via upregulation of nuclear factor-kappa B (NF-κB) expression and nuclear translocation. The in vivo animal model further demonstrated that CXCL1 serves as a critical promoter in osteosarcoma metastasis to the lung. The correlated expression of CXCL1 and VCAM-1 was observed in the immunohistochemistry staining from human osteosarcoma specimens. Our findings demonstrate the cascade mechanism regulating the network in lung metastasis osteosarcoma, therefore indicating that the CXCL1/CXCR2 pathway is a worthwhile candidate to further develop treatment schemas.

The Adverse Impact of Incense Smoke on Human Health: From Mechanisms to Implications.

Incense burning is a very popular activity in daily life among many parts all over the world. A growing body of both epidemiological and experimental evidences has reported the negative effects of incense use on human well-being, posing a potential threat at public significance. This work is a comprehensive review that covers the latest findings regarding the adverse impact of incense smoke on our health, providing a panoramic visualization ranging from mechanisms to implications. The toxicities of incense smoke come directly from its harmful constituents and deposition capacity in the body. Besides, reactive oxygen species-driven oxidative stress and associated inflammation seem to be plausible underlying mechanisms, eliciting various unfavorable responses. Although our current knowledge remains many gaps, this issue still has some important implications.

CXCL1 contributes to IL-6 expression in osteoarthritis and rheumatoid arthritis synovial fibroblasts by CXCR2, c-Raf, MAPK, and AP-1 pathway.

BACKGROUND: Osteoarthritis (OA) and rheumatoid arthritis (RA) are common joint disorders that are considered to be different diseases due to their unique molecular mechanisms and pathogenesis. Chemokines and their corresponding receptors have been well characterized in RA progression, but less so in OA pathogenesis. METHODS: The human primary synovial fibroblasts (SFs) were obtained from human OA and RA tissue samples. The Western blot and qPCR were performed to analyze the expression levels of CXCL1, as well as CXCL-promoted IL-6 expression in both OASFs and RASFs. The signal cascades that mediate the CXCL1-promoted IL-6 expression were identified by using chemical inhibitors, siRNAs, and shRNAs. RESULTS: Here, we found that both diseases feature elevated levels of CXCL1 and interleukin (IL)-6, an important proinflammatory cytokine that participates in OA and RA pathogenesis. In OASFs and RASFs, CXCL1 promoted IL-6 expression in a dose- and time-dependent manner. In OASFs and RASFs overexpressing CXCL1 or transduced with shRNA plasmid, IL-6 expression was markedly upregulated. CXCR2, c-Raf, and MAPKs were found to regulate CXCL1-induced IL-6 expression in OASFs and RASFs. Finally, CXCL1 triggered the transcriptional activities of c-Jun (which regulates the expression of proinflammatory proteins) in OASFs and RASFs. CONCLUSIONS: Our present work suggests that the CXCL1/CXCR2 axis helps to orchestrate inflammatory responses in OA and RA SFs.

The Inducible Role of Ambient Particulate Matter in Cancer Progression via Oxidative Stress-Mediated Reactive Oxygen Species Pathways: A Recent Perception.

Cancer is one of the leading causes of premature death and overall death in the world. On the other hand, fine particulate matter, which is less than 2.5 microns in aerodynamic diameter, is a global health problem due to its small diameter but high toxicity. Accumulating evidence has demonstrated the positive associations between this pollutant with both lung and non-lung cancer processes. However, the underlying mechanisms are yet to be elucidated. The present review summarizes and analyzes the most recent findings on the relationship between fine particulate matter and various types of cancer along with the oxidative stress mechanisms as its possible carcinogenic mechanisms. Also, promising antioxidant therapies against cancer induced by this poison factor are discussed.

Urban Particulate Matter Enhances ROS/IL-6/COX-II Production by Inhibiting MicroRNA-137 in Synovial Fibroblast of Rheumatoid Arthritis.

BACKGROUND: Rheumatoid arthritis (RA) has been associated with air pollution, possibly due to the augmentation of inflammatory effects. In this study, we aimed to determine the roles of inflammatory pathways and microRNA involved in the pathogenesis of RA fibroblast-like synoviocytes (FLS) inflammation induced by particulate matter. METHODS: The inflammatory mediators, messenger RNAs, microRNAs and their interrelationships were investigated using western blotting, QPCR, ELISA and immunohistochemistry. RESULTS: Particulate matter (PMs) induced an increase in the expression of interleukin-6 (IL-6) and cyclooxygenase-II (COX-II) in RA-FLS and microRNA-137 was found definitely to mediate the inflammatory pathways. PMs-induced generation of reactive oxygen species (ROS) in RA-FLS was attenuated by pretreatment with antioxidants. Nox-dependent ROS generation led to phosphorylation of ERK1/2, p38 and JNK, followed by downregulation of microRNA-137. In vivo studies, the joints of rats exposed to PMs revealed synovial fibroblast inflammation under pathologic examination and the expressions of IL-6 and COX-II were obviously increased. PMs exposure results in activated ROS-mediated mitogen-activated protein kinase (MAPK) signaling pathways and cause increased IL-6 and COX-II through downregulation of hsa-miRNA-137, which lead to inflammation and RA exacerbation. CONCLUSIONS: microRNA-137 plays an important role in PMs-induced RA acute exacerbation through MAPK signaling pathways and IL-6/COX-II activation. Targeting these mechanisms can potentially be used to develop new therapeutic strategies and prevention of RA inflammation in the future.