Lung cancer is the leading cause of cancer-related deaths worldwide with poor prognosis. Programmed cell death (PCD) plays a crucial function in tumor progression and immunotherapy response in lung adenocarcinoma (LUAD). Integrative machine learning procedure including 10 methods was performed to develop a prognostic cell death signature (CDS) using TCGA, GSE30129, GSE31210, GSE37745, GSE42127, GSE50081, GSE68467, GSE68571, and GSE72094 dataset. The correlation between CDS and tumor immune microenvironment was evaluated using various methods and single cell analysis. qRT-PCR and CCK-8 assay were conducted to explore the biological functions of hub gene. The prognostic CDS developed by Lasso + survivalSVM method was regarded as the optimal prognostic model. The CDS had a stable and powerful performance in predicting the clinical outcome of LUAD and served as an independent risk factor in TCGA and 8 GEO datasets. The C-index of CDS was higher than that of clinical stage and many developed signatures for LUAD. LUAD patients with low CDS score had a higher PD1&CTLA4 immunophenoscore, higher TMB score, lower TIDE score and lower tumor escape score, indicating a better immunotherapy benefit. Single cell analysis revealed a strong and frequent communication between epithelial cells and cancer-related fibroblasts by specific ligand-receptor pairs, including COL1A2-SDC4 and COL1A2-SDC1. Vitro experiment showed that SLC7A5 was upregulated in LUAD and knockdown of SLC7A5 obviously suppressed tumor cell proliferation. Our study developed a novel CDS for LUAD. The CDS served as an indicator for predicting the prognosis and immunotherapy benefits of LAUD patients.

Lung cancer (LC) occupies an important position in the lethality of cancer patients. Acquired resistance to gefitinib in lung adenocarcinoma (LUAD) seriously affects the therapeutic efficacy of LC. Thus, it is of major scientific and clinical significance to probe the mechanism of gefitinib resistance in LUAD for ameliorating the prognosis of patients. The expression of miRNAs in gefitinib-resistant LUAD cells was validated using qRT-PCR. Cell viability was assessed through CCK-8, whereas cell death was examined through PI staining. Changes in the ferroptosis process were evaluated by detecting the intracellular Glutathione (GSH), Malondialdehyde (MDA), and Reactive Oxygen Species (ROS) levels. Downstream targets of miR-138-5p were verified via luciferase reporter and RNA pull-down assays. RIP and qRT-PCR were employed to evaluate pri-miR-138-5p binding to DiGeorge critical region 8 (DGCR8) and the pri-miR-138-5p m6A modification level. Additionally, the impact of fat mass and obesity-associated protein (FTO) on LUAD gefitinib sensitivity was assessed in vivo by constructing a xenograft model. We observed that miR-138-5p was notably diminished in gefitinib-resistant cells. Overexpression of miR-138-5p suppressed viability while facilitated cell death and intracellular ferroptosis in gefitinib-resistant cells. Moreover, lipocalin 2 (LCN2) was the downstream target of miR-138-5p. The biological functions of miR-138-5p on gefitinib-resistant cells was reversed by introduction of LCN2. FTO suppressed the binding of DGCR8 to pri-miR-138-5p through m6A modification, thereby restraining the processing of miR-138-5p. Meanwhile, silencing of FTO enhanced the sensitivity of LUAD to gefitinib treatment. FTO suppressed the processing of miR-138-5p and then modulated the proliferation, death, and ferroptosis of gefitinib-resistant cells through the miR-138-5p/LCN2 pathway, which may put forward novel insights for clinically ameliorating the therapeutic effect of gefitinib in LUAD.

Liver hepatocellular carcinoma (LIHC) is characterized by high morbidity, rapid progression and early metastasis. Although many efforts have been made to improve the prognosis of LIHC, the situation is still dismal. Inability to initiate anoikis process is closely associated with cancer proliferation and metastasis, affecting patients’ prognosis. In this study, a corresponding gene signature was constructed to comprehensively assess the prognostic value of anoikis-related genes (ARGs) in LIHC. Using TCGA-LIHC dataset, the mRNA levels of the differentially expressed ARGs in LIHC and normal tissues were compared by Student t test. And prognostic ARGs were identified through Cox regression analysis. Prognostic signature was established and then externally verified by ICGC-LIRI-JP dataset and GES14520 dataset via LASSO Cox regression model. Potential functions and mechanisms of ARGs in LIHC were evaluated by functional enrichment analyses. And the immune infiltration status in prognostic signature was analyzed by ESTIMATE algorithm and ssGSEA algorithm. Furthermore, ARGs expression in LIHC tissues was validated via qRT-PCR and IHC staining from the HPA website. A total of 97 differentially expressed ARGs were detected in LIHC tissues. Functional enrichment analysis revealed these genes were mainly involved in MAP kinase activity, apoptotic signaling pathway, anoikis and PI3K-Akt signaling pathway. Afterward, the prognostic signature consisting of BSG, ETV4, EZH2, NQO1, PLK1, PBK, and SPP1 had a moderate to high predictive accuracy and served as an independent prognostic indicator for LIHC. The prognostic signature was also applicable to patients with distinct clinical parameters in subgroup survival analysis. And it could reflect the specific immune microenvironment in LIHC, which indicated high-risk group tended to profit from ICI treatment. Moreover, qRT-PCR and IHC staining showed increasing expression of BSG, ETV4, EZH2, NQO1, PLK1, PBK and SPP1in LIHC tissues, which were consistent to the results from TCGA database. The current study developed a novel prognostic signature comprising of 7 ARGs, which could stratify the risk and effectively predict the prognosis of LIHC patients. Furthermore, it also offered a potential indicator for immunotherapy of LIHC.

Background Non-small cell lung cancer (NSCLC) is a common cancer in the United States. Previous studies have shown that circular RNAs (circRNAs) can affect NSCLC progression, but its regulatory mechanism is still indistinct. In this study, we unfold the roles of circular RNA_0007385 in NSCLC tissues and cells. Methods Expression levels of circ_0007385, microRNA-493-3p (miR-493-3p) and Ras-related protein Rab-22A (RAB22A) were detected by quantitative real-time polymerase chain reaction (qRT-PCR) in NSCLC tissues and cells. Cell proliferation, apoptosis and stemness were examined by cell counting kit 8 (CCK8) assay, 5-ethynyl-2′-deoxyuridine (EdU) assay, flow cytometry analysis and sphere-formation assay. The interaction between miR-493-3p and circ_0007385 or RAB22A was forecasted by bioinformatic analysis and detected by dual-luciferase reporter assay, RNA immunoprecipitation (RIP) and RNA pulldown assays. In vivo experiments were implemented to verify the effect of circ_0007385 in vivo. Results Expression of circ_0007385 and RAB22A increased, whereas miR-493-3p level was decreased in NSCLC tissues in contrast to that in normal tissues. For functional analysis, circ_0007385 deficiency inhibited cell proliferation and stemness, whereas it promoted cell apoptosis in NSCLC cells. Mechanically, circ_0007385 acted as a miR-493-3p sponge to modulate RAB22A expression. Moreover, circ_0007385 could regulate the development of NSCLC by sponging miR-493-3p to regulate the expression of RAB22A. In addition, circ_0007385 silence also attenuated tumor growth in vivo. Conclusions Circ_0007385 promoted NSCLC progression by sponging miR-493-3p to increase RAB22A expression, which also offered an underlying targeted therapy for NSCLC treatment.

Lung adenocarcinoma (LUAD) is one of the most common tumors with the highest cancer-related death rate worldwide. Early diagnosis of LUAD can improve survival. Abnormal expression of the Toll-like receptors (TLRs) is related to tumorigenesis and development, inflammation and immune infiltration. However, the role of TLRs as an immunotherapy target and prognostic marker in lung adenocarcinoma is not well understood and needs to be analyzed. Relevant data obtained from databases such as ONCOMINE, UALCAN, GEPIA, and the Kaplan–Meier plotter, GSCALite, GeneMANIA, DAVID 6.8, Metascape, LinkedOmics and TIMER, to compare transcriptional TLRs and survival data of patients with LUAD. The expression levels of TLR1/2/3/4/5/7/8 in LUAD tissues were significantly reduced while the expression levels of TLR6/9/10 were significantly elevated. LUAD patients having low expression of TLR1/2/3/5/8 and high expression of TLR9 had a poor overall survival while patients with low expression of TLR2/3/7 presented with worse first progress. TLR4, TLR7 and TLR8 are the 3 most frequently mutated genes in the TLR family. Correlation suggested a low to moderate correlation among TLR family. TLR family was also involved in the activation or inhibition of the famous cancer related pathways. Analysis of immune infiltrates analysis suggested that TLR1/2/7/8 levels significantly correlated with immune infiltration level. Enrichment analysis revealed that TLRs were involved in TLR signaling pathway, immune response, inflammatory response, primary immunodeficiency, regulation of IL-8 production and PI3K-Akt signaling pathway. Our results provided information on TLRs expression and potential regulatory networks in LUAD. Moreover, our results suggested TLR2/7/8 as a potential prognostic biomarker for lung adenocarcinoma.