Therapeutic Target For Lung Cancer Research Articles

Therapeutic targets for lung cancer: genome-wide Mendelian randomization and colocalization analyses.

Lung cancer, categorized into non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC), remains a significant global health challenge. The development of drug resistance and the heterogeneity of the disease necessitate the identification of novel therapeutic targets to improve patient outcomes. We conducted a genome-wide Mendelian randomization (MR) and colocalization analysis using a comprehensive dataset of 4,302 druggable genes and cis-expressed quantitative trait loci (cis-eQTLs) from 31,884 blood samples. The study integrated genomic analysis with eQTL data to identify key genes associated with lung cancer risk. The analysis revealed five actionable therapeutic targets for NSCLC, including LTB4R, LTBP4, MPI, PSMA4, and TCN2. Notably, PSMA4 demonstrated a strong association with both NSCLC and SCLC risks, with odds ratios of 3.168 and 3.183, respectively. Colocalization analysis indicated a shared genetic etiology between these gene expressions and lung cancer risk. Our findings contribute to precision medicine by identifying druggable targets that may be exploited for subtype-specific lung cancer therapies.

Research and Progress on the Association of Porphyromonas gingivalis with Lung Cancer

Porphyromonas gingivalis is a key pathogenic microorganism that triggers periodontitis. It is closely associated with oral diseases such as chronic periodontitis and recently found to have a significant correlation with the occurrence, progression, and prognosis of cancer. As the leading malignant tumor in terms of both incidence and mortality worldwide, lung cancer has always been a focus and hotspot of research. The causes of lung cancer are complex and involve multiple factors, including smoking, occupational factors, air pollution, ionizing radiation, diet and nutrition, genetic factors, etc. Researchers have also begun to pay attention to the relationship between oral microbiota and overall health, especially the link with lung cancer. The article summarizes the latest advancements in research on Porphyromonas gingivalis in lung cancer, primarily encompassing etiology and pathogenic mechanisms, and explores its potential as a therapeutic target for lung cancer, aiming to provide new insights and directions for lung cancer prevention and treatment strategies. .

Progress in the Study of Mechanisms Clinically Relevant to Insulin Resistance and Lung Cancer

At present, the incidence and mortality rates of lung cancer rank top among malignant tumors. The early diagnosis, treatment and drug resistance of lung cancer still remain as problems in the management of lung cancer. Researchers are dedicated to identifying reliable biomarkers as predictive indicators or effective therapeutic targets for lung cancer. Insulin resistance (IR), a disorder characterized by reduced biological activity of insulin, leads to increased insulin secretion. In recent years, more and more studies have revealed the association between IR and the occurrence and development of cancer, with the insulin/insulin-like growth factor signaling pathway possibly playing a crucial role. In this article, we will focus on the relationship between IR and lung cancer, explore the impact and mechanism of IR on the development, progression and drug resistance of lung cancer. It may guide the development of new predictive tools and therapeutic strategies, and provide new ideas for research dedicated to reducing the incidence and mortality of lung cancer. .

Cancer-associated fibroblast cell surface markers as potential biomarkers or therapeutic targets in lung cancer.

Cancer-associated fibroblasts (CAFs) are the vital constituent of the tumor microenvironment, and in communication with other cells, they contribute to tumor progression and metastasis. Fibroblasts are the proposed origin of CAFs, which are mediated by pro-inflammatory cytokines and the recruitment of immune cells akin to wound healing. Although various studies have identified different subpopulations of CAFs in lung cancer, the heterogeneity of CAFs, particularly in lung cancer, and their potential as a therapeutic target remain largely unknown. Notwithstanding CAFs were previously thought to have predominantly tumor-promoting features, their pro- or anti-tumorigenic properties may depend on various conditions and cell origins. The absence of distinct markers to identify CAF subpopulations presents obstacles to the successful therapeutic targeting and treatment of CAFs in cancer. Human clinical and animal studies targeting CAFs have shown that targeting CAFs exacerbates the disease progression, suggesting that subpopulations of CAFs may exert opposing functions in cancer progression. Therefore, it is essential to pinpoint specific markers capable of characterizing these subpopulations and revealing their mechanisms of function. The cell-specific surface markers of CAFs will serve as an initial step in investigating precise CAF subpopulations and their role in diagnosing and targeting therapy against cancer-promoting CAF subsets in lung cancer.

Exploring the Role of CBX3 as a Potential Therapeutic Target in Lung Cancer.

Epigenetic changes regulate gene expression through histone modifications, chromatin remodeling, and protein translation of these modifications. The PRC1 and PRC2 complexes shape gene repression via histone modifications. Specifically, the CBX protein family aids PRC1 recruitment to chromatin, impacting the progressive multistep process driving chromatin silencing. Among family members, CBX3 is a complex protein involved in aberrant epigenetic mechanisms that drive lung cancer progression. CBX3 promotes lung tumorigenesis by interacting with key pathways such as PI3K/AKT, Ras/KRAS, Wnt/β-catenin, MAPK, Notch, and p53, leading to increased proliferation, inhibition of apoptosis, and enhanced resistance to therapy. Given our current lack of knowledge, additional research is required to uncover the intricate mechanisms underlying CBX3 activity, as well as its involvement in molecular pathways and its potential biomarker evaluation. Specifically, the dissimilar roles of CBX3 could be reexamined to gain a greater insight into lung cancer pathogenesis. This review aims to provide a clear overview of the context-related molecular profile of CBX3, which could be useful for addressing clinical challenges and developing novel targeted therapies based on personalized medicine.

ATF1 promotes ferroptosis resistance in lung cancer through enhancing mRNA stability of PROM2

BackgroundFerroptotic proteins are promising therapeutic targets for lung cancer. The PROM2 is upregulated in lung cancer and known to suppress ferroptosis. This study examined the molecular mechanisms for PROM2-induced ferroptosis resistance in lung cancer. MethodsFerroptosis in lung cancer was assessed by iron kit, and transmission electron microscopy was applied to observe the changes in mitochondrial morphology. BODIPY™ was applied to test the lipid ROS, and MeRIP was performed to test the m6A modification of PROM2. RIP assay was employed for confirming the binding between METTL3 and PROM2. In addition, dual luciferase assay was employed for exploring the transcriptional regulation of ATF1 to METTL3, and the binding relation between ATF1 and METTL3 promoter region was explored by ChIP assay. ResultsExpression levels of PROM2 were significantly higher in lung cancer cell lines than a noncancerous control line, and PROM2 knockdown significantly reduced both cancer cell viability and proliferation rate. In addition, PROM2 knockdown reduced xenograft tumor growth and exacerbated erastin-induced ferroptosis. Compared to PROM2 mRNA from control cells, transcripts in lung cancer cells exhibited enhanced m6A levels, and showed greater binding with METTL3. Further, ATF1 upregulated METTL3 transcription, thereby stabilizing PROM2 mRNA and increasing ferroptosis resistance. ConclusionATF1 could promote ferroptosis resistance in lung cancer through enhancing mRNA stability of PROM2. Thus, our work might shed novel insights on discovering therapeutic strategy for lung cancer.

Development of a genome atlas for discriminating benign, preinvasive, and invasive lung nodules.

To tackle misdiagnosis in lung cancer screening with low-dose computed tomography (LDCT), we aimed to compile a genome atlas for differentiating benign, preinvasive, and invasive lung nodules and characterize their molecular pathogenesis. We collected 432 lung nodule tissue samples from Chinese patients, spanning benign, atypical adenomatous hyperplasia (AAH), adenocarcinoma in situ (AIS), minimally invasive adenocarcinoma (MIA), and invasive adenocarcinoma (IA). We performed comprehensive sequencing, examining somatic variants, gene expressions, and methylation levels. Our findings uncovered EGFR and TP53 mutations as key drivers in - early lung cancer development, with EGFR mutation frequency increasing with disease progression. Both EGFR mutations and EGF/EGFR hypo-methylation activated the EGFR pathway, fueling cancer growth. Transcriptome analysis identified four lung nodule subtypes (G1-4) with distinct molecular features and immune cell infiltrations: EGFR-driven G1, EGFR/TP53 co-mutation G2, inflamed G3, stem-like G4. Estrogen/androgen response was associated with the EGFR pathway, proposing a new therapy combining tyrosine kinase inhibitors with antiestrogens. Preinvasive nodules exhibited stem cell pathway enrichment, potentially hindering invasion. Epigenetic regulation of various genes was essential for lung cancer initiation and development. This study provides insights into the molecular mechanism of neoplastic progression and identifies potential diagnostic biomarkers and therapeutic targets for lung cancer.

SENP2-NDR2-p21 axis modulates lung cancer cell growth

Sentrin/small ubiquitin-like modifier (SUMO)-specific proteases (SENPs) perform pivotal roles in SUMO maturation and recycling, which modulate the balance of SUMOylation/de-SUMOylation and spatiotemporal functions of SUMOylation targets. The malfunction of SENPs often results in cellular dysfunction and various diseases. However, studies rarely investigated the correlation between SENP2 and lung cancer. This study revealed that SENP2 is a required contributor to lung cancer-cell growth and targets nuclear Dbf2-related 2 (NDR2, also known as serine/threonine kinase 38L or STK38L) for de-SUMOylation, which improves NDR2 kinase activity. This condition leads to the instability of downstream target p21 in accelerating the G1/S cell cycle transition and suggests SENP2 as a promising therapeutic target for lung cancer in the future. Specifically, astragaloside IV, an active ingredient of Jinfukang Oral Liquid (JOL, a clinical combination antilung cancer drug approved by the National Food and Drug Administration (FDA) of China), can repress lung cancer-cell growth via the SENP2–NDR2–p21 axis, which provides new insights into the molecular mechanism of JOL for lung cancer treatment.

Systematic druggable genome-wide Mendelian randomization identifies therapeutic targets for lung cancer

BackgroundDrug repurposing provides a cost-effective approach to address the need for lung cancer prevention and therapeutics. We aimed to identify actionable druggable targets using Mendelian randomization (MR).MethodsSummary-level data of gene expression quantitative trait loci (eQTLs) were sourced from the eQTLGen resource. We procured genetic associations with lung cancer and its subtypes from the TRICL, ILCCO studies (discovery) and the FinnGen study (replication). We implemented Summary-data-based Mendelian Randomization analysis to identify potential therapeutic targets for lung cancer. Colocalization analysis was further conducted to assess whether the identified signal pairs shared a causal genetic variant.FindingsIn the main analysis dataset, we identified 55 genes that demonstrate a causal relationship with lung cancer and its subtypes. However, in the replication cohort, only three genes were found to have such a causal association with lung cancer and its subtypes, and of these, HYKK (also known as AGPHD1) was consistently present in both the primary analysis dataset and the replication cohort. Following HEIDI tests and colocalization analyses, it was revealed that HYKK (AGPHD1) is associated with an increased risk of squamous cell carcinoma of the lung, with an odds ratio and confidence interval of OR = 1.28,95%CI = 1.24 to 1.33.InterpretationWe have found that the HYKK (AGPHD1) gene is associated with an increased risk of squamous cell carcinoma of the lung, suggesting that this gene may represent a potential therapeutic target for both the prevention and treatment of lung squamous cell carcinoma.

Pan-cancer analysis predict that FAT1 is a therapeutic target and immunotherapy biomarker for multiple cancer types including non-small cell lung cancer.

FAT1, a substantial transmembrane protein, plays a pivotal role in cellular adhesion and cell signaling. Numerous studies have documented frequent alterations in FAT1 across various cancer types, with its aberrant expression being linked to unfavorable survival rates and tumor progression. In the present investigation, we employed bioinformatic analyses, as well as in vitro and in vivo experiments to elucidate the functional significance of FAT1 in pan-cancer, with a primary focus on lung cancer. Our findings unveiled FAT1 overexpression in diverse cancer types, including lung cancer, concomitant with its association with an unfavorable prognosis. Furthermore, FAT1 is intricately involved in immune-related pathways and demonstrates a strong correlation with the expression of immune checkpoint genes. The suppression of FAT1 in lung cancer cells results in reduced cell proliferation, migration, and invasion. These collective findings suggest that FAT1 has potential utility both as a biomarker and as a therapeutic target for lung cancer.

Proteome-Wide Multicenter Mendelian Randomization Analysis to Identify Novel Therapeutic Targets for Lung Cancer

IntroductionLung cancer (LC) remains a leading cause of cancer mortality worldwide, underscoring the urgent need for novel therapeutic targets. The integration of Mendelian randomization (MR) with proteomic data presents a novel approach to identifying potential targets for LC treatment. MethodsThis study utilized a proteome-wide MR analysis, leveraging publicly available data from genome-wide association studies (GWAS) and protein quantitative trait loci (pQTL) studies. We analyzed genetic association data for LC from the TRICL-ILCCO Consortium and proteomic data from the Decode cohort. The MR framework was employed to estimate the causal effects of specific proteins on LC risk, supplemented by external validation, co-localization analyses, and exploration of protein–protein interaction (PPI) networks. ResultsOur analysis identified five proteins (TFPI, ICAM5, SFTPB, COL6A3, EPHB1) with significant associations to LC risk. External validation confirmed the potential therapeutic relevance of ICAM5 and SFTPB. Co-localization analyses and PPI network exploration provided further insights into the biological pathways involved and their potential mechanistic roles in LC pathogenesis. ConclusionThe study highlights the power of integrating genomic and proteomic data through MR analysis to uncover novel therapeutic targets for lung cancer. The identified proteins, particularly ICAM5 and SFTPB, offer promising directions for future research and development of targeted therapies, demonstrating the potential to advance personalized medicine in lung cancer treatment.

RACGAP1 promotes lung cancer cell proliferation through the PI3K/AKT signaling pathway

We aimed to investigate the expression and clinic significance of Rac GTPase Activating Protein 1 (RACGAP1) in human lung adenocarcinoma (LUAD). Online database analysis revealed a significant increase in RACGAP1 mRNA expression among 26 types of tumor tissues, including LUAD tissues. Online database and tissue microarray analyses indicated that RACGAP1 expression was significantly upregulated in LUAD tissues. Genetic variation analysis identified four different genetic variations of RACGAPs in LUAD. Moreover, online database analysis showed that RACGAP1 upregulation was correlated with shorter survival in patients with LUAD. After silencing RACGAP1 expression in A549 cells using siRNA and assessing its protein levels via Western blotting, we found that RACGAP1 knockdown inhibited cell growth and induced apoptosis determined using the Cell Counting Kit-8 assay, colony formation assay, and flow cytometry. Mechanistically, western blot analysis indicated that Bax expression increased, whereas Bcl-2 expression decreased. Moreover, RACGAP1 knockdown attenuated PI3K/AKT pathway activation in lung cancer cells. Taken together, our findings showed that RACGAP1 was overexpressed in LUAD tissues and played an important role in lung cancer by increasing cell growth through the PI3K/AKT signaling pathway. This study suggests recommends evaluating RACGAP1 in clinical settings as a novel biomarker and potential therapeutic target for lung cancer.

Pathogenic role of super-enhancers as potential therapeutic targets in lung cancer.

Lung cancer is still one of the deadliest malignancies today, and most patients with advanced lung cancer pass away from disease progression that is uncontrollable by medications. Super-enhancers (SEs) are large clusters of enhancers in the genome's non-coding sequences that actively trigger transcription. Although SEs have just been identified over the past 10years, their intricate structure and crucial role in determining cell identity and promoting tumorigenesis and progression are increasingly coming to light. Here, we review the structural composition of SEs, the auto-regulatory circuits, the control mechanisms of downstream genes and pathways, and the characterization of subgroups classified according to SEs in lung cancer. Additionally, we discuss the therapeutic targets, several small-molecule inhibitors, and available treatment options for SEs in lung cancer. Combination therapies have demonstrated considerable advantages in preclinical models, and we anticipate that these drugs will soon enter clinical studies and benefit patients.

Abstract LB299: Dihydrouridine synthase 2 sustains levels of tRNACys and prevents ferroptosis in lung cancer

Abstract Dihydrouridine is a universally conserved tRNA modification installed by enzymes that are important for human health. High expression of dihydrouridine synthase 2 (DUS2) predicts poor patient outcomes in lung adenocarcinoma (LUAD) for reasons that are not yet clear. Here, we show in human cells and mouse xenografts that DUS2 suppresses ferroptosis, a metal-dependent non-apoptotic form of cell death that is emerging as a therapeutic target in lung cancer. Elevated DUS2 correlates with resistance to ferroptosis inducers and loss of DUS2 causes increased sensitivity with concomitant accumulation of toxic lipid peroxides. Mechanistically, DUS2 is required to maintain tRNA CysGCA levels, supporting translation of cysteine-rich proteins including metallothioneins, key regulators of metal and redox homeostasis Notably, DUS2 KO cells cannot sustain normal levels of metallothioneins, a class of very cysteine rich proteins that serve as key regulators of both metal and redox homeostasis. Accordingly, DUS2 knockout cells are more susceptible to zinc intoxication and have lower levels of reduced glutathione, which partially explains their sensitivity to ferroptosis. Our findings demonstrate that DUS2 is required to support tRNACys levels and fend off ferroptosis in lung cancer cells. This highlights that individual tRNA substrates can play an outsized role in the biological functions of tRNA modifying enzymes, and demonstrates the therapeutic potential of targeting DUS2 in cancer. Citation Format: Austin Draycott, Matthew C. Wang, Diana Martínez Saucedo, Luisa Escobar-Hoyos, Wendy Gilbert. Dihydrouridine synthase 2 sustains levels of tRNACys and prevents ferroptosis in lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB299.

High CASC expression predicts poor prognosis of lung cancer: A systematic review with meta-analysis.

The long non-coding RNA cancer susceptibility candidate (CASC) has abnormal expression in lung cancer tissues and may correlate with lung cancer prognosis. This study aimed to comprehensively evaluate the association between CASC expression and the cancer prognosis. PubMed, Embase, Web of Science, Google Scholar, Cochrane Library, and China National Knowledge Infrastructure databases were searched until April 1, 2023, to obtain the relevant literature. Studies that met the predefined eligibility criteria were included, and their quality was independently assessed by 2 investigators according to the Newcastle-Ottawa Scale (NOS) score. Detailed information was obtained, such as first author, year of publication, and number of patients. Hazard ratio (HR) with a 95% confidence interval (CI) was extracted and grouped to assess the relationship between CASC expression and cancer prognosis. The dichotomous data was merged and shown as the odds ratio (OR) with a 95% CI was extracted to assess the relationship between CASC expression and clinicopathological parameters. A total of 12 studies with 746 patients with lung cancer were included in the meta-analysis. The expression levels of lncRNA CASC2 and CASC7 were decreased, while those of CASC9, 11, 15, and 19 were induced in lung cancer tissues compared with paracancerous tissues. In the population with low CASC expression (CASC2 and CASC7), high CASC expression indicated a good lung cancer prognosis (HR = 0.469; 95% CI, 0.271-0.668). Conversely, in the population with high CASC expression (CASC9, 11, 15, and 19), high CASC expression predicted a poor lung cancer outcome (HR = 1.910; 95% CI, 1.628-2.192). High CASC expression also predicted worse disease-free survival (DFS) (HR = 2.803; 95% CI, 1.804-6.319). Combined OR with 95% CI revealed an insignificant positive association between high CASC expression and advanced TNM stage (OR = 1.061; 95% CI, 0.775-1.454), LNM (OR = 0.962; 95% CI, 0.724-1.277), tumor size (OR = 0.942; 95% CI, 0.667-1.330), and histological grade (OR = 1.022; 95% CI, 0.689-1.517). The CASC expression levels negatively correlate with lung cancer prognosis. Therefore, CASC expression may serve as a prognostic marker and a potential therapeutic target for lung cancer.

Fat-soluble Vitamins and Lung Cancer: Where We Are?

Fat-soluble vitamins (vitamins A, D, E, and K) are vital substances for maintaining normal physiological functions in the body. In recent years, scholars have explored the relationship between fat-soluble vitamins and the wasting disease - lung cancer. In this paper, we review recent studies on fat-soluble vitamins and lung cancer to clarify the relevance and molecular mechanisms of various vitamins in lung cancer, and whether the levels of fat-soluble vitamins in the body and vitamin supplementation affect the development of lung cancer. Our review could facilitate the discovery of biomarkers, potential therapeutic targets in lung cancer, and anti-tumor adjuvant drugs, in addition to highlighting other new ideas in the prevention and treatment of lung cancer.

Rolapitant treats lung cancer by targeting deubiquitinase OTUD3

BackgroundLung cancer is cancer with the highest morbidity and mortality in the world and poses a serious threat to human health. Therefore, discovering new treatments is urgently needed to improve lung cancer prognosis. Small molecule inhibitors targeting the ubiquitin-proteasome system have achieved great success, in which deubiquitinase inhibitors have broad clinical applications. The deubiquitylase OTUD3 was reported to promote lung tumorigenesis by stabilizing oncoprotein GRP78, implying that inhibition of OTUD3 may be a therapeutic strategy for lung cancer.ResultsIn this study, we identified a small molecule inhibitor of OTUD3, Rolapitant, by computer-aided virtual screening and biological experimental verification from FDA-approved drugs library. Rolapitant inhibited the proliferation of lung cancer cells by inhibiting deubiquitinating activity of OTUD3. Quantitative proteomic profiling indicated that Rolapitant significantly upregulated the expression of death receptor 5 (DR5). Rolapitant also promoted lung cancer cell apoptosis through upregulating cell surface expression of DR5 and enhanced TRAIL-induced apoptosis. Mechanistically, Rolapitant directly targeted the OTUD3-GRP78 axis to trigger endoplasmic reticulum (ER) stress-C/EBP homologous protein (CHOP)-DR5 signaling, sensitizing lung cancer cells to TRAIL-induced apoptosis. In the vivo assays, Rolapitant suppressed the growth of lung cancer xenografts in immunocompromised mice at suitable dosages without apparent toxicity.ConclusionIn summary, the present study identifies Rolapitant as a novel inhibitor of deubiquitinase OTUD3 and establishes that the OTUD3-GRP78 axis is a potential therapeutic target for lung cancer.

Abstract 4379: RING1, a novel E3 ubiquitin ligase for CIP2A, negatively regulates smoking-induced lung tumorigenesis

Abstract Lung cancer is the second incidence rate of all new cancer diagnoses and the leading cause of cancer-related deaths globally. To develop novel diagnostic and therapeutic targets for lung cancer, there are emerging needs for molecular biological research on the occurrence and progression. Among the targets, CIP2A has been studied for promoting various cancer types, but detailed underlying mechanisms are needed to be further investigated. In this study, it was verified that CIP2A is overexpressed in lung cancer tissues, particularly amongst those with a smoking history, compared to adjacent normal tissues. CIP2A knockdown in lung cancer cells efficiently reduced cell proliferation and migration capacity. Through the mass spectrometry analysis on A549 cells overexpressing CIP2A, RING1 was identified as a candidate for E3 ligase of CIP2A. The interaction of the two proteins and ubiquitin chain regulation by RING1 was verified by immunoprecipitation. RING1 knockdown enhanced proliferation and migration of lung cancer cells, and these effects result from the upregulation of CIP2A and its downstream molecules, c-Myc and cyclin B1. To further study a trigger for RING1 expression changes in lung tumorigenesis, cigarette smoke extract (CSE) was applied for the following experiments. CSE treatment depleted RING1 mRNA, including protein expression. Decreased RING1 level led to upregulation of CIP2A and c-MYC. Collectively, these results reveal novel roles of the RING1 and CIP2A in lung cancer progression caused by smoking and propose a potential biomarker candidate for the therapeutic and diagnostic targets. Citation Format: In-ho Jeong, Chang-Whan Peter Lee, Hwan Jung Lim, Seong Jun Park, Ji Young Hyun. RING1, a novel E3 ubiquitin ligase for CIP2A, negatively regulates smoking-induced lung tumorigenesis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4379.

CircSCUBE3 promoted ferroptosis to inhibit lung adenocarcinoma progression.

CircRNAs can regulate ferroptosis and affect cancer development and are promising biomarkers and therapeutic targets in lung cancer. circSCUBE3 is expressed in lung adenocarcinoma (LUAD) tissues. In this study, our purpose was to study the role and regulatory mechanism of circSCUBE3 in LUAD ferroptosis. circSCUBE3 was identified to be significantly downregulated in LUAD samples and cell lines. The expression of biomarkers related to lipid oxidation (4-HNE) and ferroptosis (Ptgs2) was both downregulated in LUAD tissues, suggesting the ferroptosis resistance in LUAD. Erastin, a ferroptosis inducer, was used to stimulate the LUAD cells for 48 h. The cell viability, 4-HNE and Ptgs2 level of LUAD cells were decreased by exposure to erastin while the expression of circSCUBE3 was not significantly altered. We then overexpressed circSCUBE3 in LUAD cells and found it decreased the GSH level and GSH/GSSG ratio in LUAD cells. CircSCUBE3 might serve as an independent factor of ferroptosis and may induce ferroptosis in LUAD by inhibiting GSH synthesis. The loss-of-function experiments were conducted, and circSCUBE3 deficiency reversed the erastin-induced reduction in cell viability, GSH level, GSH/GSSG ratio, mitochondrial membrane potential and elevation in MDA content, Ptgs2, 4-HNE expression as well as lipid ROS production. CircSCUBE3 negatively regulated GPX4 expression in LUAD cells, and the silencing of GPX4 counteracted the impact of circSCUBE3 deficiency on LUAD cell viability as well as ferroptosis, suggesting that circSCUBE3 regulated the GPX4-mediated GSH synthesis in LUAD. CircSCUBE3 was to bind to CREB, which activated the transcription of GPX4. CircSCUBE3 negatively regulated GPX4 expression by competitively interacting with CREB. In the tumor-bearing mouse models, circSCUBE3 silencing promoted tumor growth and reversed the erastin treatment-induced inhibition on tumorigenesis in vivo. In conclusion, circSCUBE3 inhibited LUAD development by promoting ferroptosis via the CREB/GPX4/GSH axis, which might provide a novel option for the LUAD targeted therapy.

Silencing lncRNA-DARS-AS1 suppresses nonsmall cell lung cancer progression by stimulating miR-302a-3p to inhibit ACAT1 expression.

Long noncoding RNAs (LncRNAs) have been gaining attention as potential therapeutic targets for lung cancer. In this study, we investigated the expression and biological behavior of lncRNA DARS-AS1, its predicted interacting partner miR-302a-3p, and ACAT1 in nonsmall cell lung cancer (NSCLC). The transcript level of DARS-AS1, miR-302a-3p, and ACAT1 was analyzed using qRT-PCR. Endogenous expression of ACAT1 and the expression of-and changes in-AKT/ERK pathway-related proteins were determined using western blotting. MTS, Transwell, and apoptosis experiments were used to investigate the behavior of cells. The subcellular localization of DARS-AS1 was verified using FISH, and its binding site was verified using dual-luciferase reporter experiments. The binding of DARS-AS1 to miR-302a-3p was verified using RNA co-immunoprecipitation. In vivo experiments were performed using a xenograft model to determine the effect of DARS-AS1 knockout on ACAT1 and NSCLC. lncRNA DARS-AS1 was upregulated in NSCLC cell lines and tissues and the expression of lncRNA DARS-AS1 was negatively correlated with survival of patients with NSCLC. Knockdown of DARS-AS1 inhibited the malignant behaviors of NSCLC via upregulating miR-302a-3p. miR-302a-3p induced suppression of malignancy through regulating oncogene ACAT1. This study demonstrates that the DARS-AS1-miR-302a-3p-ACAT1 pathway plays a key role in NSCLC.