Lung Cancer Progression Research Articles

Abstract A015: Aging limits stemness and tumor development in the lung by reprogramming iron homeostasis

Abstract Aging is the most important and well-recognized risk factor for cancer. Aging leads to systemic decline of physical fitness, significantly changing the macroenvironment from the early tumor initiation to the terminal stage of metastasis. However, the underlying mechanisms only start to emerge. Here, using physiologically aged autochthonous genetically engineered mouse models (GEMMs) and primary cells, we demonstrate that aging suppresses lung cancer initiation and progression by degrading stemness of the alveolar cell of origin. Using single-cell transcriptomics, we uncover a distinct compositional landscape of cancer cell subsets in aged lung tumors, revealing a delay in the molecular progression of the lung lesions and an age-specific gene expression signature. Interestingly, key components of this gene signature were traced back to the aged cell of origin. Furthermore, the age-specific signature derived from GEMMs was predictive of patient age in human lung cancer, indicating conservation of the age-associated changes across species. Interestingly, our preliminary data suggested that tumor cells derived from aged tumor-bearing mice displayed higher metastatic potential, indicating that different mechanisms may govern tumor initiation and metastasis. Functional interrogation of the age-specific gene signature revealed that the loss of stemness and tumorigenic capacity is underpinned by aging-associated induction of the transcription factor NUPR1. We find that NUPR1 is induced in the cell of origin in aged mice and humans, which leads to a functional iron insufficiency in the aged cells. Genetic inactivation of the NUPR1 or iron supplementation restores stemness and promotes tumorigenic potential of aged alveolar cells. Conversely, targeting NUPR1 is detrimental to young alveolar cells by promoting ferroptosis. We find that aging-associated DNA hypomethylation at specific enhancer sites results in elevated NUPR1 expression, which is recapitulated in young cells by inhibition of DNA methylation. We uncover that, unlike the young, aged alveolar cells are functionally iron insufficient, which leads to loss of stemness and resistance to ferroptosis. Our results indicate that aging-associated reprogramming of the cell of origin determines tumor initiation potential, alters trajectory of tumor evolution and produces age-dependent vulnerabilities. These findings demonstrate that aging fundamentally changes the biology of lung cancer, shedding light on novel therapeutic modulation of cellular iron homeostasis or ferroptosis in regenerative medicine and in cancer prevention for the elderly population. Citation Format: Xueqian Zhuang, Qing Wang, Simon Joost, Alexander Ferrena, Melissa Blum, Klavdija Krause, Zhuxuan Li, Deyou Zheng, Emily S Wong, Tuomas Tammela. Aging limits stemness and tumor development in the lung by reprogramming iron homeostasis [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr A015.

Abstract PR013: A vagal sensory-to-sympathetic axis restrains anti-tumor immunity

Abstract Solid tumors are innervated by distinct branches of the peripheral nervous system, and increased tumor innervation has been associated with poor cancer outcomes. However, it remains unexplored whether different types of nerves function together to sense and respond to a tumor, and how neural networks shape cancer immunity. As a major interoceptive system, vagal nerves sense a large variety of body signals and are critical for maintaining physiological homeostasis of visceral organs including the lung. While distinct vagal sensory neuron (VSN) subtypes have been identified to differently regulate pulmonary functions, it is unknown whether these VSNs interact with lung tumors and how they influence cancer progression. Here, we uncover that sensory nerves act through the sympathetic circuit to restrain anti-cancer immunity. Mechanistically, our data suggest that lung tumors hijack the vagal interoceptive system to activate sympathetic efferent nerves in the tumor microenvironment (TME), which in turn drive immune suppression via β2-adrenergic signaling in alveolar macrophages. Our key findings include: By applying anterograde labeling, tissue-clearing and 3D imaging to genetically engineered mouse models, we found that lung adenocarcinoma is richly innervated by vagal sensory nerves. We also showed that neurotrophic factors produced by cancer cells directly promote vagal sensory innervation. Furthermore, scRNA-seq analysis revealed tumor-induced transcriptional reprogramming of lung-innervating VSNs. Using multiple genetic tools to selectively label and deplete different VSN subtypes, we found that Npy2r + /Trpv1 + VSNs but not P2ry1 + VSNs innervate lung tumors and control lung cancer progression by inhibiting anti- cancer immunity. At the organism level, we demonstrated that vagal NPY2R/TRPV1 neurons inhibit anti-cancer immunity via the sympathetic axis. Depletion of vagal NPY2R/TRPV1 neurons resulted in reduced sympathetic nerve activity and a decreased norepinephrine level in the lung TME, whereas pharmacological activation of the sympathetic pathway suppressed the anti-tumor immune responses and restored tumor growth in mice lacking Npy2r + /Trpv1 + VSNs. At the molecular and cellular level, we identified that the vagal-to-sympathetic axis predominantly functions through β2-adrenergic signaling in alveolar macrophages (AMs) to drive immune suppression. AM depletion or selective deletion of β2-adrenergic receptor (ADRB2) in AMs derepressed the anti-tumor immunity and abolished the tumor-inhibiting effect of Npy2r + /Trpv1 + VSN ablation. Taken together, our study establishes an essential role of the sensory-to-sympathetic circuit in controlling cancer immunosurveillance, supporting the notion that the functional integration of sensory and sympathetic nerves systemically regulates anti- cancer immunity. Translationally, our findings from the preclinical model suggest that targeted disruption of the vagal sensory-to-sympathetic axis may provide new treatments for visceral organ cancers by enhancing anti-tumor immunity. Citation Format: Haohan Wei, Chuyue Yu, Bo Hu, Xing Zeng, Hiroshi Ichise, Ronald N. Germain, Rui Chang, Chengcheng Jin. A vagal sensory-to-sympathetic axis restrains anti-tumor immunity [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr PR013.

Abstract C029: PM2.5-induced drug resistance in lung cancer

Abstract Long-term exposure to PM2.5 air pollution is a significant contributor to lung cancer incidence. Our previous studies have shown that such exposure promotes lung cancer progression by activating the EGFR (epidermal growth factor receptor) and AhR (aryl hydrocarbon Receptor) pathways. We observed that in lung cancer cells with EGFR mutations, prolonged PM2.5 exposure induces EGFR activation, resulting in accelerated tumor cell growth both in vitro and in vivo. This suggests that PM2.5 may play a role in the resistance to EGFR-TKI (tyrosine kinase inhibitor) therapies, raising concerns about treatment efficacy. To explore this, we exposed the EGFR-mutant lung cancer cell line to PM2.5 for 90 days. Our results revealed that long-term exposure not only reduced the therapeutic effect of EGFR-TKIs but also increased the expression of cMyc, a gene linked to poor prognosis and drug resistance. We further confirmed that PM2.5-induced EGFR-TKI resistance is driven by the AhR-cMyc pathway. AhR, activated by environmental toxins in PM2.5, increases cMyc expression, leading to drug resistance. When we administered cMyc inhibitors, the PM2.5-exposed cells regained sensitivity to EGFR-TKI therapy. These findings indicate that targeting the AhR-cMyc pathway could be a promising approach to overcome PM2.5-induced resistance in lung cancer treatment. Further research is needed to explore the broader implications of environmental pollution on cancer therapy and to develop strategies to counteract the effects of pollutants like PM2.5. Citation Format: Chi-Yuan Chen, Chieh-Wen Chan, Tong-Hong Wang. PM2.5-induced drug resistance in lung cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr C029.

Antagonism of the ATP-gated P2X7 receptor inhibits the proliferation of hepatocellular carcinoma cells.

The P2X7 receptor, an ATP-gated ion channel which belongs to the P2X receptor family, plays critical roles in recognizing extracellular adenosine 5'-triphosphate (ATP) and is widely expressed in most tumor cells as well as inflammatory cells. Previously, the P2X7 receptor has been demonstrated to modulate the progression of various malignancies, including glioblastoma, pancreatic cancer, lung cancer, leukemia, and lymphoma. However, the biological function and prognostic values of P2X7 receptor in hepatocellular carcinoma remain to be determined. Here, we investigated the expression level of P2X7 receptor in patients with hepatocellular carcinoma. Then MTS and EdU assays were carried out to study the role of P2X7 receptor blockade in the proliferation of hepatocellular carcinoma cells. In addition, the underlying mechanism was further elucidated by bulk RNAseq. Compared to the control group, the P2X7 receptor was significantly up-regulated in the hepatocellular carcinoma group. Interestingly, A740003 and A438079, two selective antagonists at P2X7 receptor, significantly blocked Ca2+ influx and decreased the proliferative rate of hepatocellular carcinoma cells. Furthermore, the expression level of chondroitin sulfate synthase 1 (CHSY1), an enzyme that mediates the polymerization step of chondroitin sulfate, was reduced by both A740003 and A438079. In conclusion, inhibition of the P2X7 receptor attenuated the proliferation of hepatocellular carcinoma cells, and this process was largely modulated by CHSY1. Thus, our findings reveal a previously unknown role for P2X7 receptor in the proliferation of hepatocellular carcinoma cells and imply that the P2X7 receptor may represent a new target for the treatment of hepatocellular carcinoma.

The Role of Ribonucleotide Reductase M2 in Lung Cancer Progression and Chemotherapy Resistance: A Bioinformatics Analysis and Review.

The Role of Ribonucleotide Reductase M2 in Lung Cancer Progression and Chemotherapy Resistance: A Bioinformatics Analysis and Review.

CSIG-12. YAP1-TEAD SIGNALING CONTRIBUTES TO LUNG CANCER COLONIZATION OF THE BRAIN

Abstract BACKGROUND Lung cancer is the most common primary tumor to metastasize to the brain. Poor understanding of the brain metastasis process limits therapeutic options. Despite emerging data on the role of YAP signaling pathway in the development of brain tumors, a gap in knowledge remains regarding its role in brain colonization. We hypothesize that YAP1 and the associated TEAD transcriptional factors are responsible for lung cancer progression and that intervention with YAP/TEAD-targeted therapy will prevent brain dissemination. METHODS Lung cancer cells at different stages of cancer progression (VMRC-LCD and NCI-H1975, lung cancer cell lines; NCI-H1915 and LN001, brain metastatic cancer cells) were genetically engineered to overexpress or silence/knockout YAP1 using lentiviral transduction of constructs expressing shRNA/sgRNA or YAP1. We tested several tumor cell capabilities using well-established in vitro assays, including invasion and migration assays, and an in vivo brain metastasis (BM) model to determine the biological effects of YAP1/TEAD suppression at different stages of lung cancer progression. Dose-response assays were performed to determine IC50 of the TEAD inhibitor, verteporfin. RESULTS YAP overexpression enhances the proliferative phenotype in metastatic and BM cell lines but not in non-metastatic cells. However, YAP overexpression only increases the migration ability of BM cell lines such as LN001 and NCI-H1915 compared to the metastatic NCI-H1975 and non-metastatic lung cancer cells. Moreover, we showed the efficacy of the YAP1/TEAD inhibitor in patient-derived lung BM cells. Finally, our in vivo preliminary data showed YAP1 involvement in lung cancer cell colonization of the brain but not in sustaining brain metastasis growth. CONCLUSIONS Our findings showed YAP1 involvement in lung cancer cell colonization of the brain, suggesting YAP1 inhibition is a clinically actionable target for preventing lung cancer dissemination and providing a strong rationale to further evaluate the benefit of a YAP1/TEAD-targeted therapy in in vivo models of BM.

BIOM-35. COMPREHENSIVE IDENTIFICATION OF MRNA ISOFORMS AND THEIR DIAGNOSTIC POTENTIAL IN GLIOMAS

Abstract Most genes generate multiple mRNA isoforms which may differ in their protein-coding capacity. Also, cancer and its prognosis are associated with the altered expression of specific isoforms of a variety of genes as cancer cells can manipulate regulatory mechanisms to express isoforms that provide a survival advantage and/or resistance to therapy. However, the underlying mechanisms behind their pathology are poorly understood. Fifty seven glioma samples that could be categorized unambiguously into Astrocytoma (n=17), Oligodendroglioma (n=16) and Glioblastoma (n=24) based on pathology reports and according to WHO standards were selected for this analysis. Total RNA-Sequencing (RNA-Seq) was performed on RNA isolated from these 57 samples. RNA-Seq data analysis was performed using the DRAGEN RNA application in Illumina BaseSpace and transcript counts were generated after alignment. From these counts, isoforms that were significantly differentially expressed in Astrocytoma (Astro) vs Oligodendroglioma (Oligo), and Astrocytoma vs Glioblastoma (GBM) were identified using the R package, IsoformSwitchAnalyzeR. Approximately 93,000 transcripts were screened in both comparisons of which 4388 and 44 transcript switches were identified as significant at FDR<0.05 in the Astro vs GBM and Astro vs Oligo comparisons, respectively. Applying an additional cut-off based on the difference in isoform fraction or dIF of a transcript between the two groups being compared (dIF>1.0 and dIF<-0.1), the most significant top switches were identified.. Similarly, in the Astro vs GBM comparison, the isoform switch in genes such as MDF1 and RER1 whose overexpression is known to be involved in tumorigenesis and metastasis were among the 155 top switches. Among the six top switches in the Astro vs. Oligo comparison were transcripts of the RENBP and GCNT2 genes which play an important role in the progression of melanoma, gastric and lung cancers. These results indicate that there may be isoform-specific dysregulation within gliomas, and further suggest that their biological significance and diagnostic potential can be explored.

CNSC-61. NEURONAL-ACTIVITY DEPENDENT MECHANISMS OF SMALL CELL LUNG CANCER PATHOGENESIS

Abstract Neural activity is increasingly recognized as a crucial regulator of cancer growth. In the brain, neuronal activity robustly influences glioma growth both through paracrine mechanisms and through electrochemical integration of malignant cells into neural circuitry via neuron-to-glioma synapses. Outside of the CNS, innervation of tumors such as prostate, breast, pancreatic, and gastrointestinal cancers by peripheral nerves similarly regulates cancer progression. However, the extent to which the nervous system regulates lung cancer progression, either in the lung or when metastatic to the brain, is less well understood. Small cell lung cancer (SCLC) is a lethal high-grade neuroendocrine tumor that exhibits a strong propensity to metastasize to the brain. Here we demonstrate that SCLC cells in the brain co-opt neuronal activity-regulated mechanisms to stimulate growth and progression. With in vivo optogenetic stimulation, we show that glutamatergic and GABAergic cortical neuronal activity each drive proliferation of SCLC through both paracrine and synaptic neuron-cancer interactions. In the brain, SCLC cells form bona fide neuron-to-SCLC synapses evident on immunoelectron microscopy for the first time for non-brain derived malignancy. Using electrophysiology and two-photon calcium imaging, we find that SCLC cells exhibit depolarizing currents with consequent calcium transients in response to neuronal activity. SCLC cell membrane depolarization is sufficient to promote the growth of intracranial tumors. We also demonstrate reciprocal effects of SCLC on neurons, manifesting as increased neuronal synaptogenesis and elevated field potentials in regions of the tumor. Finally, in the lung, vagus nerve transection markedly inhibits primary lung tumor formation and development and awards survival benefit in spontaneous genetic SCLC model, highlighting a critical role for innervation in overall SCLC growth. Taken together, these studies illustrate that neuronal activity plays a crucial role in dictating SCLC pathogenesis in both the lung and the brain.

RBM15 facilitates osimertinib resistance of lung adenocarcinoma through m6A-dependent epigenetic silencing of SPOCK1.

Lung cancer is the leading cause of cancer-related mortality globally. N6-methyladenosine (m6A) is the most abundant modification in mammalian mRNA and is involved in the biological regulation of tumors, including lung cancer. However, the role of m6A-related proteins, such as RNA-binding motif protein 15 (RBM15), in lung cancer progression remains largely unknown. Our study indicated that RBM15 is significantly overexpressed in lung adenocarcinoma, serving as an independent prognostic factor for poor outcomes and facilitating tumor cell proliferation and migration. RBM15 was markedly elevated in patients with EGFR mutations, correlating with a poorer prognosis, while it had negligible prognostic value in EGFR wild-type patients. As EGFR-tyrosine kinase inhibitors (TKIs) are the standard treatment for patients with EGFR mutations, we subsequently determined that RBM15 drives osimertinib resistance via a novel mechanism: enhancing m6A modification of cwcv- and kazal-like domains proteoglycan 1 (SPOCK1) mRNA, promoting epithelial-mesenchymal transition-mediated osimertinib resistance through a bypass activation pathway. These findings were validated in osimertinib-resistant H1975 cells and organoids from patients with osimertinib-resistant lung adenocarcinoma. Furthermore, the RBM15-SPOCK1 axis was activated in drug-tolerant persister cells, indicating that early targeting of RBM15 during EGFR-TKI treatment could dramatically extend the patient response and benefit from TKI therapy. Our results emphasize the critical role of RBM15 in reversing EGFR-TKI resistance and propose it as a promising therapeutic target for prolonging TKI treatment benefits in patients with lung adenocarcinoma.

A causal association between chemokines and the risk of lung cancer: a univariate and multivariate mendelian randomization study

BackgroundObservational studies and experimental evidence have shown that chemokines play important roles in lung cancer development, progression, and treatment. However, few studies have examined the causal association between them.MethodsSummary data of chemokines and lung cancer were obtained from genome-wide association studies. Mendelian randomization (MR) analyses were performed by five methods, Inverse variance weighted (IVW), Weighted median estimation, MR-Egger, Simple mode and Weighted, with IVW as the primary analysis method. Sensitivity analysis was used to assess the reliability of the MR results. Multivariate Mendelian randomization studies were used to infer whether causality was influenced by potential mediators. The expression levels of CCL21 were analyzed by quantitative real-time PCR.ResultsWe found that CCL21 was negatively associated with lung adenocarcinoma risk. CCL25 was positively associated with lung squamous cell carcinoma risk. CCL5 was negatively associated with small cell lung cancer risk. CCL21, CCL24, CCL27, and CCL28 was positively associated with small cell lung cancer risk. After multivariate Mendelian randomization adjustment for smoking behavior, it was found that the effect of CCL25 on lung squamous cell cancer disappeared, and the effect of CCL21 on small cell lung cancer was quite opposite to the univariate. The receiver operating characteristic curve indicated that chemokines had high accuracy in the diagnosis of lung cancer. CCL21 expression levels showed large differences in lung adenocarcinoma cells.ConclusionThese results highlighted the causal effects of chemokines on lung cancer and suggested a mediating role of smoking behavior in the association between chemokines and lung cancer.

Discovery of 4-(4-(3-(1-(2-(piperidin-1-yl)ethyl)-1H-benzo[d]imidazole-2-yl)isoxazol-5-yl)phenyl)morpholine as a novel c-Myc inhibitor against lung cancer in vitro and in vivo

The critical role of c-Myc as a driving factor in the development and progression of lung cancer establishes it as a pivotal target for anti-lung cancer therapeutic research. In our previous study, we reported on the discovery of D347–2761, a novel small-molecule inhibitor that specifically targets the unstable domain of c-Myc and disrupts the c-Myc/Max heterodimer. To enhance targeted therapies further, we conducted an extensive structural analysis and designed a series of innovative benzimidazole derivatives. The cytotoxic activities of these compounds were assessed using the CCK-8 assay, revealing that compound A1 displayed IC50 values of 6.32 μM and 11.39 μM against the A549 and NCI–H1299 lung cancer cell lines, respectively, while compound A5 exhibited IC50 values of 4.08 μM and 7.86 μM against the same cell lines. Our findings revealed that compounds A1 and A5 exhibited potent anticancer activity by disrupting the interaction between c-Myc and Max proteins, leading to the downregulation of c-Myc protein levels and induction of apoptosis through apoptotic pathways. Notably, compound A5 demonstrated superior inhibitory capacity compared to other compounds tested. Furthermore, in a syngeneic tumor model, compound A5 exhibited excellent efficacy with a tumor growth inhibition rate reaching up to 76.4 %, accompanied by a significant reduction in c-Myc protein expression levels. Therefore, compound A5 holds promise as a potential agent for targeting c-Myc in anti-lung cancer therapy.

Mechanisms of microRNA Regulation of the Epithelial–Mesenchymal Transition (EMT) in Lung Cancer

Lung cancer remains the cancer with the highest mortality worldwide, largely due to a limited understanding of the precise molecular mechanisms that drive its progression. microRNAs (miRNAs) have emerged as crucial regulators of lung cancer progression by influencing key cellular processes, notably the epithelial–mesenchymal transition (EMT). EMT is a complex and potentially reversible process where epithelial cells lose their polarity and adhesion, reorganize their cytoskeleton, and transition to a mesenchymal phenotype, enhancing their migratory and invasive capacities. While EMT plays an essential role in normal physiological contexts such as tissue development and wound healing, it is also a critical mechanism underlying the progression and metastasis of lung cancer. This review aims to summarize the latest research findings on the role of endogenous and exosome-derived microRNAs in regulating EMT in lung cancer, focusing on studies conducted over the past five years. It also provides an overview of EMT’s essential molecular mechanisms to better understand how miRNAs regulate EMT in lung cancer.

O-GlcNAcylation of hexokinase 2 modulates mitochondrial dynamics and enhances the progression of lung cancer.

Non-small cell lung cancer (NSCLC) stands as the prevailing manifestation of lung cancer, with current therapeutic modalities linked to a dismal prognosis, necessitating further advancements. Hexokinase 2 (HK2), a critical enzyme positioned on the mitochondrial membrane, exerts control over diverse biological pathways, thereby regulating cancer. Nevertheless, the precise role and mechanism of HK2 in NSCLC remain inadequately elucidated, warranting comprehensive investigation. HK2 expression in NSCLC tissues and cell lines was detected through immunohistochemistry and western blot analysis. Concurrently, shRNA assays were applied to scrutinize the impact of HK2 on cell proliferation, apoptosis, migration, and invasion processes in NSCLC cell lines, utilizing CCK8, flow cytometry, wound-healing assay, and transwell techniques. The involvement of HK2 in mitochondrial dynamics was probed through western blot analysis, mitochondrial membrane potential assay, and assessment of ROS generation. Next, the functional role of HK2 was assessed by examining its influence on xenograft tumor growth in nude mice in vivo. Further research has demonstrated that HK2 played a role in NSCLC through its O-GlcNAcylation process. The results of the study revealed that HK2 O-GlcNAcylation promoted the proliferation, migration, and invasive characteristics of NSCLC cells, while alleviating mitochondrial damage, whereas O-GlcNAcylation inactivation yielded the opposite effect. Furthermore, in vivo experiments in nude mice illustrated that HK2 O-GlcNAcylation could stimulate tumor growth in NSCLC. These results suggested that HK2 may impact mitochondrial dynamics in NSCLC through its O-GlcNAcylation, thereby contributing to the progression of NSCLC.

A subset of neutrophils activates anti-tumor immunity and inhibits non-small-cell lung cancer progression.

Neutrophils in the tumor microenvironment (TME) are heterogeneous populations associated with cancer prognosis and immunotherapy. However, the plasticity and function of heterogeneous neutrophils in the TME of non-small-cell lung cancer (NSCLC) remain unclear. Here, we show that neutrophils produce high levels of interleukin (IL)-8, which induce the differentiation of CD74highSiglecFlow neutrophils and suppress the generation of CD74lowSiglecFhigh neutrophils in the TME of IL-8-humanized NSCLC mice. The CD74highSiglecFlow neutrophils boost anti-tumor Tcell responses via antigen cross-presentation. Deleting CD74 in IL-8-humanized neutrophils impairs Tcell activation and exacerbates NSCLC progression, whereas a CD74 agonist enhances Tcell activation and the efficacy of anti-programmed cell death 1 (PD-1) or osimertinib therapies. Additionally, the CD74highCD63low neutrophils in the TME and peripheral blood of advanced NSCLC patients phenocopy the CD74highSiglecFlow neutrophils in the TME of NSCLC mice and correlate well with the responsiveness to anti-PD-1 plus chemotherapies. These findings demonstrate an IL-8-CD74high neutrophil axis that promotes anti-tumor immunity in NSCLC.

High mitochondrial DNA levels accelerate lung adenocarcinoma progression.

Lung adenocarcinoma is a common aggressive cancer and a leading cause of mortality worldwide. Here, we report an important in vivo role for mitochondrial DNA (mtDNA) copy number during lung adenocarcinoma progression in the mouse. We found that lung tumors induced by KRASG12D expression have increased mtDNA levels and enhanced mitochondrial respiration. To experimentally assess a possible causative role in tumor progression, we induced lung cancer in transgenic mice with a general increase in mtDNA copy number and found that they developed a larger tumor burden, whereas mtDNA depletion in tumor cells reduced tumor growth. Immune cell populations in the lung and cytokine levels in plasma were not affected by increased mtDNA levels. Analyses of large cancer databases indicate that mtDNA copy number is also important in human lung cancer. Our study thus reports experimental evidence for a tumor-intrinsic causative role for mtDNA in lung cancer progression, which could be exploited for development of future cancer therapies.

Neuronatin Promotes the Progression of Non-small Cell Lung Cancer by Activating the NF-κB Signaling.

Understanding the regulatory mechanisms involving neuronatin (NNAT) in non-small cell lung cancer (NSCLC) is an ongoing challenge. This study aimed to elucidate the impact of NNAT knockdown on NSCLC by employing both in vitro and in vivo approaches. To investigate the role of NNAT, its expression was silenced in NSCLC cell lines A549 and H226. Subsequently, various parameters, including cell proliferation, invasion, migration, and apoptosis, were assessed. Additionally, cell-derived xenograft models were established to evaluate the effect of NNAT knockdown on tumor growth. The expression of key molecules, including cyclin D1, B-cell leukemia/lymphoma 2 (Bcl-2), p65, matrix metalloproteinase (MMP) 2, and nerve growth factor (NGF) were examined both in vitro and in vivo. Nerve fiber density within tumor tissues was analyzed using silver staining. Upon NNAT knockdown, a remarkable reduction in NSCLC cell proliferation, invasion, and migration was observed, accompanied by elevated levels of apoptosis. Furthermore, the expression of cyclin D1, Bcl-2, MMP2, and phosphorylated p65 (p-p65) showed significant downregulation. In vivo, NNAT knockdown led to substantial inhibition of tumor growth and a concurrent decrease in cyclinD1, Bcl-2, MMP2, and p-p65 expression within tumor tissues. Importantly, NNAT knockdown also led to a decrease in nerve fiber density and downregulation of NGF expression within the xenograft tumor tissues. Collectively, these findings suggest that neuronatin plays a pivotal role in driving NSCLC progression, potentially through the activation of the nuclear factor-kappa B signaling cascade. Additionally, neuronatin may contribute to the modulation of tumor microenvironment innervation in NSCLC. Targeting neuronatin inhibition emerges as a promising strategy for potential anti-NSCLC therapeutic intervention.

Agrimonolide Inhibits the Malignant Progression of Non-small Cell Lung Cancer and Induces Ferroptosis through the mTOR Signaling Pathway.

Non-Small Cell Lung Cancer (NSCLC), a prevalent type of lung cancer, has a poor prognosis and contributes to a high mortality rate. Agrimonolide, which belongs to the Rosaceae family, possesses various biomedical activities. This study aimed to explore the efficacy and mechanism of agrimonolide in NSCLC. The viability, proliferation, and tumor-forming ability of A549 cells were detected using the Cell Counting Kit-8 assay (CCK-8) assay, EdU staining, and colony formation assay. The cell cycle was detected using flow cytometry. Cell migration and invasion were detected using wound healing and transwell assays. Western blot was used to detect Epithelial-Mesenchymal Transition (EMT)-, ferroptosis-, and mechanistic targets of rapamycin (mTOR) signaling pathway-related proteins. Lipid peroxidation was detected using the thiobarbituric acid reactive substances (TBARS) assay kit, while lipid Reactive Oxygen Species (ROS) was detected using a BODIPY 581/591 C11 kit. The level of Fe2+ was detected using corresponding assay kits. In this study, agrimonolide with varying concentrations (10, 20, and 40 μM] could inhibit the proliferation, induce cycle arrest, suppress metastasis, induce ferroptosis, and block the mTOR signaling pathway in NSCLC cells. To further reveal the mechanism of agrimonolide associated with the mTOR signaling pathway in NSCLC, mTOR agonist MHY1485 (10 μM) was used to pre-treat A549 cells, and functional experiments were conducted again. It was found that the protective effects of AM on NSCLC cells were all partially abolished by MHY1485 pre-treatment. Agrimonolide inhibited the malignant progression of NSCLC and induced ferroptosis by blocking the mTOR signaling pathway, thus indicating the potential of agrimonolide as a prospective candidate for treating NSCLC.

(-)-Epicatechin regulates endoplasmic reticulum stress and promotes ferroptosis in lung cancer cells via the PERK/eIF2α/ATF4 signaling pathway.

(-)-Epicatechin (EC) is an active ingredient of Fagopyrum dibtrys (D. Don) Hara and can regulate lung cancer progression. However, the specific regulatory mechanism is poorly understood. This study explored the specific mechanism of EC in the treatment of lung cancer. H460 cells were injected subcutaneously into the left dorsal sides of nude mice to establish an animal model of lung cancer. H460 and H1299 cells and nude mice were treated with different concentrations of EC. The expression levels of related proteins were detected by Western blotting. Cell proliferation, migration, and invasion were detected by CCK-8, colony formation, and Transwell assays. Flow cytometry was used to detect the Ca2+ level in lung cancer cells. Immunohistochemistry was used to detect the expression of Ki-67 in tumor tissues. This study revealed that ferroptosis in lung cancer cells was inhibited during lung cancer development. EC treatment promotes ferroptosis, inhibits the proliferation, migration and invasion of lung cancer cells, and inhibits the formation of tumors in vivo. Ferroptosis inhibitors (Fer-1) weaken the effects of EC on lung cancer cells, whereas a ferroptosis inducer (erastin) further promotes the effects of EC. In addition, endoplasmic reticulum (ER) stress is involved in the EC-induced ferroptosis of lung cancer cells, and treatment with GSK, an inhibitor of the ER stress protein PERK, can reverse the effect of EC. EC therapy activates the PERK-eIF2α-ATF4 signaling pathway to increase ER stress, thereby promoting ferroptosis in lung cancer cells and inhibiting the occurrence and development of lung cancer. Our research suggests that EC may become a drug candidate for treating lung cancer.

SLIT3 deficiency promotes non-small cell lung cancer progression by modulating UBE2C/WNT signaling.

In our prior research, it was noted that slit guidance ligand 3 (SLIT3), a member of the SLIT-secreted protein family, may play a potential role in tumorigenesis. In addition, our prior work has found that the SLIT3 gene is highly methylated, especially in advanced-stage lung cancer tissues. Herein, we propose the hypothesis that abnormal SLIT3 expression may be linked to lung cancer development. In this study, decreased SLIT3 at the transcriptome and proteome levels was observed in lung cancer tissues. Furthermore, the downregulation of SLIT3 was related to a higher tumor stage and poorer prognosis. Silencing SLIT3 expression enhanced cell proliferation and migration, indicating potential characteristics of a tumor suppressor gene of SLIT3 in non-small-cell lung cancer (NSCLC). Furthermore, SLIT3 deficiency stimulates UBE2C upregulation and regulates NSCLC progression through Wnt3A/β-catenin signaling. The activation of the WNT signaling pathway was highly correlated with chemoresistance development in lung cancer. In conclusion, SLIT3 deficiency promotes lung cancer onset and progression by modulating UBE2C/WNT signaling. SLIT3/UBE2C/WNT may serve as novel biomarkers and therapeutic targets in NSCLC.

CircSEC24A induces KLF8 expression to promote the malignant progression of non-small cell lung cancer by regulating miR-1253.

This study aimed to analyze the role of circSEC24A in non-small cell lung cancer (NSCLC) and its underlying mechanism. RNA levels of circSEC24A, microRNA-1253 (miR-1253), and KLF transcription factor 8 (KLF8) were detected by quantitative real-time polymerase chain reaction. Protein expression was analyzed by western blot or immunohistochemistry assay. Cell proliferation and apoptosis were investigated by colony formation assay, 5-ethynyl-2'-deoxyuridine assay, and flow cytometry analysis. Glycolysis was evaluated by commercial kits. Dual-luciferase reporter assay and RNA immunoprecipitation assay were conducted to identify the associations among circSEC24A, miR-1253, and KLF8. Xenograft mouse model assay was used to evaluate the effect of circSEC24A on tumor tumorigenesis. CircSEC24A and KLF8 were upregulated, while miR-1253 was downregulated in NSCLC. CircSEC24A knockdown inhibited proliferation and glycolysis but induced the apoptosis of NSCLC cells. CircSEC24A acted as a miR-1253 sponge and regulated NSCLC cell malignancy by targeting miR-1253. KLF8 was identified as a target of miR-1253, and its overexpression attenuated miR-1253-induced effects in NSCLC cells. Besides, circSEC24A upregulated KLF8 by sponging miR-1253. Further, circSEC24A knockdown suppressed NSCLC cell tumorigenesis in vivo. CircSEC24A silencing inhibited NSCLC cell malignancy through the miR-1253/KLF8 pathway, providing a potential therapeutic target for NSCLC.