TFR1-Mediated Iron Metabolism Orchestrates Tumor Ferroptosis and Immunity in Non-Small Cell Lung Cancer.

This study aimed to investigate the underlying molecular mechanisms of transferrin receptor (TFR1) in non-small cell lung cancer (NSCLC). Histological analysis was performed using hematoxylin-eosin (HE) staining. The number of CD8+ T cell were determined by flow cytometry and immunofluorescence assays. mRNA levels were analyzed by qRT-PCR. Protein expression was detected by western blot. Ferroptosis was detected by using propidium iodide (PI) staining. Xenograft experiment was applied for determining tumor growth. The results showed that interferon (IFN)-γ plus iron dextran (FeDx) induced iron overload and the ferroptosis of NSCLC cells. Moreover, IFN-γ-mediated upregulation of TFR1 promoted ferritinophagy and tumor cell ferroptosis via blocking via blocking ferritin heavy chain 1 (FTH1)/ ferritin light chain (FTL) signaling. However, TFR1 knockout suppressed the ferroptosis of tumor cells. Furthermore, FeDx-mediated iron overload promoted the sensitivity of anti-programmed death ligand 1 (PD-L1) therapies. Clinically, TFR1 was downregulated in NSCLC patients. Low levels of TFR1 predicted decreased CD8+ T cells. Taken together, IFN-γ combined with iron metabolism therapies may provide a novel alternative for NSCLC.

Targeting TRIM9 by miR-218-5p Restricts Cell Proliferation and Epithelial-Mesenchymal Transition in Non-Small Cell Lung Cancer.

OBJECTIVE: Tripartite motif-containing protein 9 (TRIM9) has been studied in several human tumors. MicroRNA-218-5p (miR-218-5p) was predicted to target TRIM9. We aimed to investigate the roles of miR-218-5p/TRIM9 axis in non-small cell lung cancer (NSCLC). METHODS: TRIM9 and miR-218-5p expression levels in NSCLC tissues and cell lines (95D and H1299) were determined by reverse transcription quantitative PCR. UALCAN and Kaplan-Meier (KM) plotter were employed to analyze the expression level of TRIM9 in lung cancer. The interaction between TRIM9 and miR-218-5p was explored by luciferase reporter assay and Spearman correlation test. Immunohistochemistry assay was used to confirm the protein expression of TRIM9 in NSCLC tissues. Regulatory effects of TRIM9 or miR-218-5p on cell proliferation, migration and invasion, and epithelial-mesenchymal transition (EMT) process of NSCLC cells were assessed by CCK-8 assay, transwell assay and western blot analysis. RESULTS: MiR-218-5p was predicted to specifically target TRIM9 and confirmed to negatively regulate TRIM9 expression in NSCLC cells. Online bioinformatics analysis showed TRIM9 overexpression in lung cancer and predicted poor prognosis. The data from collected clinical specimens showed that miR-218-5p was downregulated, while TRIM9 was upregulated in NSCLC tissues, whose expression levels were negatively correlated. The in vitro experiments demonstrated that TRIM9 knockdown imitated the suppressive effects miR-218-5p overexpression on cell proliferation, migration, invasion and EMT process. In addition, overexpression of TRIM9 reversed the effects of miR-218-5p in NSCLC cells. CONCLUSIONS: Our results suggest that TRIM9 functions as an oncogene in NSCLC in vitro and is regulated by miR-218-5p.

Alginic acid inhibits non-small cell lung cancer-induced angiogenesis via activating miR-506 expression.

Angiogenesis is a key event in non-small cell lung cancer progression. Alginic acid (AA), a kind of naturally occurring polyuronic acid, is generally enriched in edible brown algae. Recent studies have uncovered its anti-anaphylactic and anti-inflammatory properties. However, the effects of AA on human malignancies remain unknown. Herein, efficient inhibition of AA on NSCLC-induced angiogenesis was observed with tube formation and xenograft models. Subsequent results indicated that AA downregulated the expression of VEGF-A, a key angiogenesis-inducing cytokine. In addition, AA downregulated STAT3, a transcriptional inducer of VEGF-A and increased non-coding RNA miR-506 expression, respectively. Furthermore, miR-506 directly modulated STAT3 relying on base pairing the 3'-UTR in STAT3 mRNA. We also found that abrogation of miR-506 abolished the inhibitory effect of AA on VEGF-A expression and NSCLC-induced angiogenesis. Finally, xenografts experiments also showed that oral administration of AA could significantly attenuate NSCLC angiogenesis, indicated by decreased micro-vessel density (MVD) and the MVD marker CD31 expression in xenografts tissues. Correspondingly, AA treatment also downregulated VEGF-A, STAT3 and increased miR-506 expression in xenografts samples, respectively. Taken together, these results suggested that AA could suppress NSCLC-induced angiogenesis via miR-506/STAT3/VEGF-A axis. .