Induced Lung Cancer Research Articles

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.

Asiatic acid induces lung cancer toxicity by triggering SRC-mediated ferroptosis

Ferroptosis is a recently discovered form of regulated cell death that shows promise as a novel approach for inducing tumor cell death in cancer treatment, with significant research potential. Asiatic acid (AA), a key component of the traditional Chinese medicine Centella asiatica, has been identified as having potential therapeutic benefits for various diseases, particularly cancer. Non-small cell lung cancer (NSCLC) is a challenging and prevalent form of cancer to treat. In our study, we utilized network pharmacology, molecular docking, and experimental methods to investigate the potential of AA in treating NSCLC and to elucidate its role in inhibiting cancer through the ferroptosis pathway. Through network pharmacology analysis, we identified that AA targets the core NSCLC protein SRC through the ferroptosis pathway. Our experiments demonstrated that treatment with AA led to increased iron accumulation, mitochondrial membrane potential, and expression of ferroptosis markers glutathione peroxidase 4 (GPX4), ferritin heavy chain 1 (FTH1), and acyl-CoA synthetase long chain family member 4 (ACSL4) in NSCLC cells, confirming the induction of ferroptosis. In conclusion, AA has the potential to target SRC and induce NSCLC cell death through the ferroptosis pathway, offering a promising approach for cancer treatment.

Targeted Positron Emission Tomography-Tracked Biomimetic Codelivery Synergistically Amplifies Ferroptosis and Pyroptosis for Inducing Lung Cancer Regression and Anti-PD-L1 Immunotherapy Efficacy.

The chemoresistance and systemic toxicity of cisplatin (CDDP) severely limit its application in the treatment of non-small cell lung cancer (NSCLC). Here, I-124 labeled cancer cell membrane biomimetic nanovesicles loading Polyphyllin VI (PPVI) and CDDP (termed 124I-P/C@CMLvs) were constructed to enhance the sensitivity and efficacy of CDDP. The radiochemical purity (RCP) of 124I-P/C@CMLvs reached more than 99% and maintained reliable stability in vitro. Micro-positron emission tomography (micro-PET) imaging of I-124 quantitatively revealed the distribution and specific homologous tumor targeting ability of 124I-P/C@CMLvs in vivo with superior diagnosis performance, beneficial for dynamically monitoring the efficacy against NSCLC. Loaded PPVI significantly strengthened the sensitivity of NSCLC to CDDP therapy and exerted synergistic anti-tumor effect in vitro and in vivo, which was achieved by PPVI promoting p53 deubiquitination and stimulating reactive oxygen species (ROS) production to trigger the crosstalk between the amplification of GPX4 signaling-mediated ferroptosis and NLRP3/GSDMD/Caspase-1 axis-mediated pyroptosis. 124I-P/C@CMLvs also significantly stimulated the infiltration of immune cells including dendritic cells, CD8+ T cells, and CD4+ T cells in tumor tissues (P < 0.05). The combination of 124I-P/C@CMLvs and anti-PD-L1 therapy further synergistically promoted NSCLC regression. Altogether, 124I-P/C@CMLvs provide a transformational solution to the challenge of improving CDDP sensitivity and realizing the integration of diagnosis, treatment, and monitoring of NSCLC.

Chia Seed (Salvia hispanica) Attenuates Chemically Induced Lung Carcinomas in Rats through Suppression of Proliferation and Angiogenesis.

In 2022, 2.5 million cases of lung cancer were diagnosed, resulting in 1.8 million deaths. These statistics have motivated us to introduce a new natural product which is feasible in lung cancer therapies. This comprehensive study was performed to study the effects of chia seed extracts (70% ethanol and petroleum ether) on lung cancer in vitro and in vivo models. The invitro cytotoxicity activity of the chia extracts was studied in lung cancer cell lines (A549 cells). After 48 h, chia alcohol and ether extracts showed more inhibitory influence (IC50, 16.08, and 14.8 µg/mL, respectively) on A549 cells compared to Dox (IC50, 13.6 µg/mL). In vivo, administration of chia alcohol and ether extracts (500 mg/kg/day, orally for 20 weeks) recovered 4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)-induced lung cancer, as a significant reduction in the lung cancer biomarkers, including the relative weight of the lung (20.0 and 13.33%), ICAM(31.73 and 15.66%), and c-MYC (80 and 96%) and MMP9(60 and 69%) expression genes, and improvement in these changes were observed by histopathological examinations of the lung tissues compared to the lung control. Chia seeds fought lung cancer via suppression of proliferation, angiogenesis, inflammation, and activation apoptosis. These activities may be attributed to the chemical composition of chia, which is identified by LC-Mass, such as caffeic acid, vanillic acid, kaempferol-3-O-glucuronide, and taxifolin. Finally, we can conclude that chia seeds have an anti-lung cancer effect with a good safety margin.

Mitochondrial VDAC1 Silencing in Urethane-Induced Lung Cancer Inhibits Tumor Growth and Alters Cancer Oncogenic Properties.

Alterations in cellular metabolism are vital for cancer cell growth and motility. Here, we focused on metabolic reprogramming and changes in tumor hallmarks in lung cancer by silencing the expression of the mitochondrial gatekeeper VDAC1. To better mimic the clinical situation of lung cancer, we induced lung cancer in A/J mice using the carcinogen urethane and examined the effectiveness of si-m/hVDAC1-B encapsulated in PLGA-PEI nanoparticles. si-m/hVDAC1-B, given intravenously, induced metabolism reprogramming and inhibited tumor growth as monitored using MRI. Mice treated with non-targeted (NT) PLGA-PEI-si-NT showed many large size tumors in the lungs, while in PLGA-PEI-si-m/hVDAC-B-treated mice, lung tumor number and area were markedly decreased. Immunofluorescence staining showed decreased expression of VDAC1 and metabolism-related proteins and altered expression of cancer stem cell markers. Morphological analysis showed two types of tumors differing in their morphology; cell size and organization within the tumor. Based on specific markers, the two tumor types were identified as small cell (SCLC) and non-small cell (NSCLC) lung cancer. These two types of tumors were found only in control tumors, suggesting that PLGA-PEI-si-m/hVDAC1-B also targeted SCLC. Indeed, using a xenograft mouse model of human-derived SCLC H69 cells, si-m/hVDAC1-B inhibited tumor growth and reduced the expression of VDAC1 and energy- and metabolism-related enzymes, and of cancer stem cells in the established xenograft. Additionally, intravenous treatment of urethane-induced lung cancer mice with the VDAC1-based peptide, Retro-Tf-D-LP4, showed inhibition of tumor growth, and decreased expression levels of metabolism- and cancer stem cells-related proteins. Thus, silencing VDAC1 targeting both NSCLC and SCLC points to si-VDAC1 as a possible therapeutic tool to treat these lung cancer types. This is important as target NSCLC tumors undergo transformation to SCLC.

Evaluation of Gemcitabine and Epigallocatechin-3-Gallate Loaded Solid Lipid Nanoparticles on Benzopyrene Induced Lung Cancer Model Via Intranasal Route: Improved Pharmacokinetics and Safety Profile.

The objective of this study was to create a new treatment for lung cancer using solid lipid nanoparticles (SLNs) loaded with gemcitabine (GEM) and epigallocatechin-3-gallate (EGCG) that can be administered through the nose. We analyzed the formulation for its effectiveness in terms of micromeritics, drug release, and anti-cancer activity in the benzopyrene-induced Swiss albino mice lung cancer model. We also assessed the pharmacokinetics, biodistribution, biocompatibility, and hemocompatibility of GEM-EGCG SLNs. The GEM-EGCG SLNs had an average particle size of 93.54 ± 11.02nm, a polydispersity index of 0.146 ± 0.05, and a zeta potential of -34.7 ± 0.4mV. The entrapment efficiency of GEM and EGCG was 93.39 ± 4.2% and 89.49 ± 5.1%, respectively, with a sustained release profile for both drugs. GEM-EGCG SLNs had better pharmacokinetics than other treatments, and a high drug targeting index value of 17.605 for GEM and 2.118 for EGCG, indicating their effectiveness in targeting the lungs. Blank SLNs showed no pathological lesions in the liver, kidney, and nasal region validating the safety of SLNs. GEM-EGCG SLNs also showed fewer pathological lesions than other treatments and a lower hemolysis rate of 1.62 ± 0.10%. These results suggest that GEM-EGCG SLNs could effectively treat lung cancer.

Asbestos-Related lung Cancer: An underappreciated oncological issue

Asbestos, a group of class I (WHO) carcinogenic fibers, is the main cause of mesothelioma. Asbestos inhalation also increases the risk to develop other solid tumours with lung cancer as the most prominent example [91]. The incidence of asbestos-related lung cancer (ARLC) is estimated to be to six times larger than the mesothelioma incidence thereby becoming an important health issue [86]. Although the pivotal role of asbestos in inducing lung cancer is well established, the precise causal relationships between exposures to asbestos, tobacco smoke, radon and ‘particulate’ (PM2.5) air pollution remain obscure and new knowledge is needed to establish appropriate preventive measures and to tailor existing screening practices[22,61,65]. We hypothesize that a part of the increasing numbers of lung cancer diagnoses in never-smokers can be explained by (historic and current) exposures to asbestos as well as combinations of different forms of air pollution (PM2.5, asbestos and silica).

Mitigating Effect of Matricin Against Benzo(a)pyrene-induced Lung Carcinogenesis in Experimental Mice Model.

Lung cancer is a life-threatening disease that is still prevalent worldwide. This study aims to evaluate the effects of matricin, a sesquiterpene, on the carcinogenic agent benzo(a)pyrene [B(a)P]-induced lung cancer in Swiss albino mice. Lung cancer was induced by oral administration of B(a)P at 50 mg/kg b. wt. in model Swiss-albino mice (group II) as well in experimental group III, and treated with matricin (100 mg/kg b. wt.) in group III. Upon completion of treatment for 18 weeks, the changes in body weight, tumor formation, enzymatic and non-enzymatic antioxidant levels (GSH, SOD, GPx, GR, QR, CAT), lipid peroxidation (LPO) level, pro-inflammatory cytokines (TNF-α, IL-6, IL-1β), immunoglobulin levels (IgG, IgM), apoptosis markers (Bax, Bcl-xL), tumor markers (carcinoembryogenic antigen (CEA), neuron-specific enolase (NSE)), and histopathological (H&E) alterations were determined. The results indicate that B(a)P caused a significant increase of tumor formation in the lungs, increased tumor markers and inflammatory cytokines in serum, and depletion of enzymatic/ non-enzymatic antioxidants and immunoglobulins, compared to the untreated control group. Matricin treatment significantly reversed the changes caused by B(a)P as evidenced by the biochemical and histopathological assays. The changes caused by matricin clearly indicate the cancer-preventive effects of matricin against B(a)P-induced lung cancer in animal models, which can be attributed to the antioxidant activity, immunomodulation, and mitigation of the NF-kβ pathway.

The Role and Efficacy of JNK Inhibition in Inducing Lung Cancer Cell Death Depend on the Concentration of Cisplatin.

Toxicity and the emergence of resistance are the main challenges in cancer treatment. The optimal dose of cisplatin, one of the most widely used chemotherapeutic anticancer drugs, is currently being widely debated. Furthermore, the dose-dependent molecular mechanisms of its action are poorly understood. To assess the role of protein kinase JNK (cJun N-terminal kinase) signaling in lung cancer treatment, we combined small-molecule JNK inhibitors and cisplatin. Wild-type p53 (tumor suppressor transcription factor TP53) and mutated RAS-bearing lung adenocarcinoma cell line A549 was used as a model in our studies. Here, we demonstrate cisplatin concentration-dependent opposing roles of JNK in killing cancer cells: a cell-protective role at low cisplatin concentrations and an apoptosis-promoting (or neutral) role at high concentrations. Time- and dose-dependent activation of pro-survival protein kinase AKT and TP53 was shown, with similar activation dynamics in cells exposed to different (low and high) cisplatin concentrations. Selective inhibition of AKT and activation of TP53 (expression and phosphorylation) led to a decrease in cell survival, indicating their involvement in cisplatin-induced cell death regulation. The activation levels of TP53 and AKT in cisplatin-treated A549 cells after cotreatment with the JNK inhibitor SP600125 correlated with their role in regulating cell death. TP53 and AKT were proposed as signaling proteins mediating the outcome of JNK inhibition in A549 cells exposed to different concentrations of cisplatin. Our findings suggest that a combination of stress kinase JNK inhibition and low-dose cisplatin, together with manipulation of drug-induced signaling, could be considered as a promising treatment strategy for certain lung cancers.

Acute particulate hexavalent chromium exposure induces DNA double-strand breaks and activates homologous recombination repair in rat lung tissue.

Hexavalent chromium [Cr(VI)] is an established human lung carcinogen, but the carcinogenesis mechanism is poorly understood. Chromosome instability, a hallmark of lung cancer, is considered a major driver of Cr(VI)-induced lung cancer. Unrepaired DNA double-strand breaks are the underlying cause, and homologous recombination repair is the primary mechanism preventing Cr(VI)-induced DNA breaks from causing chromosome instability. Cell culture studies show acute Cr(VI) exposure causes DNA double-strand breaks and increases homologous recombination repair activity. However, the ability of Cr(VI)-induced DNA breaks and repair impact has only been reported in cell culture studies. Therefore, we investigated whether acute Cr(VI) exposure could induce breaks and homologous recombination repair in rat lungs. Male and female Wistar rats were acutely exposed to either zinc chromate particles in a saline solution or saline alone by oropharyngeal aspiration. This exposure route resulted in increased Cr levels in each lobe of the lung. We found Cr(VI) induced DNA double-strand breaks in a concentration-dependent manner, with females being more susceptible than males, and induced homologous recombination repair at similar levels in both sexes. Thus, these data show this driving mechanism discovered in cell culture indeed translates to lung tissue in vivo.

A population level study on smoking and radon induced adenocarcinoma and small-cell carcinoma among males and females in Canada

ObjectiveTo assess if there is a relationship between residential radon exposure and two lung cancer histological types, small-cell carcinoma (diagnosed in people with a smoking history) and adenocarcinoma (the most commonly diagnosed histologic type in people who have never smoked) among males and females in Canada. MethodsWith survey data of long-term radon measurements in residential homes, long-term averaged tobacco consumption rates in the units of cigarettes per day per person and long-term averaged age-standardized lung cancer incidence rates at provincial level, simple linear fitting (ANOVA linear regression) was applied in this study to determine the effect on lung cancer induction by smoking and exposure to indoor radon, and to assess if there is a relationship between residential radon exposure and lung cancer histological types. ResultsLung cancer incidence rates correlate very well with the tobacco consumption rates (P ​< ​0.05). However, females appear to be more likely than males to develop lung cancer at a given amount of cigarette consumption. For both small-cell carcinoma and adenocarcinoma, a statistically significant correlation between incidence rate and mean radon concentration was observed for females, the correlation was much stronger for adenocarcinoma (P ​= ​0.0057) than small-cell carcinoma (P ​= ​0.0483). However, there was no such correlation for males. ConclusionIt is possible that female non-smokers are more susceptible to radon-induced lung cancer, and the joint effect of radon exposure and tobacco smoking may be worse in female smokers compared to males, such that higher incidence rate of adenocarcinoma among females compared to males were observed in recent decades, even though females never smoked more than males.

Country-specific differences in the lung tumour microbiome.

e20044 Background: Sputum examination for the early detection of lung cancer continues to be explored ( Thunnissen 2003 ), however has so far resulted in a low diagnostic yield. An increasing number of studies have evidenced a mechanistic role of the lung microbiome in the induction of lung cancer ( Liu et al., 2020 ), and the presence of bacterial biomarkers in bronchoalveolar lavage and sputum have been proposed ( Cheng et al., 2020 ). It is currently unknown whether the sputum microbiome can appropriately capture the lung tumour microbiome. Given that the lung microbiome may vary by geography, this analysis was considered over two populations: China and Italy. Methods: Microbiome analysis was performed using BioCorteX’s industry-leading knowledge graph and integrated proprietary engines v20240126_153156. Data from 9 studies was used. In total, 461 samples from lung cancer patients in China (250 sputum, 211 tumour) and 60 from Italy (34 sputum, 26 tumour) were considered. Shannon’s diversity was used to consider within-sample diversity, and dimensional scaling based (MDS) on Bray-Curtis diversity was used to consider between-sample diversity. Results: All sample were checked to have a library size greater than 100, and more than 10 unique species. Only those species present in over 1% of samples were considered to reduce noise. In both China and Italy, tumour samples had a lower diversity than sputum samples (p = 0.00016 and p &lt; 2.2e-16, respectively). Samples from Italy had a lower diversity than samples from China (p &lt; 2.22e-16). In the MDS analysis, the tumour samples from China and Italy formed two distinct, non-overlapping clusters. A third cluster was formed from the union of sputum samples from both countries. These results were independent of any study-specific effects. Conclusions: These results indicate that the sputum microbiome is not representative of the tumour microbiome, and that the divergence of the tumour microbiome away from the sputum microbiome is country specific. The results of this analysis highlight that further work into differences in the lung tumour microbiome by country is warranted, especially in light of the growing body of evidence suggesting a causative role of the microbiome in lung cancer. It is also possible that lung cancer treatments may be impacted by the country-specific nature of the lung tumour microbiome.

Hederagenin promotes lung cancer cell death by activating CHAC1-dependent ferroptosis pathway

Lung cancer poses a significant threat globally, especially in China. This puts higher demands on the treatment methods and drugs for lung cancer. Natural plants provide valuable resources for the development of anti-cancer drugs. Hederagenin (Hed) is a triterpenoid compound extracted from ivy leaves and has anti-tumor activity against multifarious cancers, including lung cancer. However, the regulatory mechanism of Hed in lung cancer remains unclear. In this study, we used Hed to treat lung cancer cells, and observed the effect of Hed on cell proliferation (including CCK-8 and colony formation experiments), apoptosis (including flow cytometry and apoptosis gene detection (BAX and Bcl-2)). The results showed that Hed induced lung cancer cell death (inhibiting proliferation and promoting apoptosis). Next, we performed bioinformatics analysis of the expression profile GSE186218 and found that Hed treatment significantly increased the expression of CHAC1 gene. CHAC1 is a ferroptosis-inducing gene. RT-qPCR detection of lung cancer clinical tissues and related cell lines also showed that CHAC1 was lowly expressed in lung cancer. Therefore, we knocked down and overexpressed CHAC1 in lung cancer cells, respectively. Subsequently, cell phenotype experiments showed that down-regulating CHAC1 expression inhibited lung cancer cell death (promoting proliferation and inhibiting apoptosis); on the contrary, up-regulating CHAC1 expression promoted lung cancer cell death. To further verify that Hed exerts anti-tumor effects in lung cancer by promoting CHAC1 expression, we performed functional rescue experiments. The results showed that down-regulating CHAC1 expression reversed the promoting effect of Hed on lung cancer cell death. Mechanistically, in vitro and in vivo experiments jointly demonstrated that Hed exerts anti-cancer effects by promoting CHAC1-induced ferroptosis. In summary, our study further enriches the regulatory mechanism of Hed in lung cancer.

P53 activation enhances the sensitivity of non-small cell lung cancer to the combination of SH003 and docetaxel by inhibiting de novo pyrimidine synthesis

BackgroundIdentifying molecular biomarkers for predicting responses to anti-cancer drugs can enhance treatment precision and minimize side effects. This study investigated the novel cancer-targeting mechanism of combining SH003, an herbal medicine, with docetaxel in non-small cell lung cancer (NSCLC) cells. Also, the present study aimed to identify the genetic characteristics of cancer cells susceptible to this combination.MethodsCell viability was analyzed by WST-8 assay. Apoptosis induction, BrdU incorporation, and cell cycle analysis were performed using flow cytometry. Metabolites were measured by LC–MS/MS analysis. Real-time PCR and western blotting evaluated RNA and protein expression. DNA damage was quantified through immunofluorescence. cBioPortal and GEPIA data were utilized to explore the mutual co-occurrence of TP53 and UMPS and UMPS gene expression in NSCLC.ResultsThe combination treatment suppressed de novo pyrimidine nucleotide biosynthesis by reducing the expression of related enzymes. This blockade of pyrimidine metabolism led to DNA damage and subsequent apoptosis, revealing a novel mechanism for inducing lung cancer cell death with this combination. However, some lung cancer cells exhibited distinct responses to the combination treatment that inhibited pyrimidine metabolism. The differences in sensitivity in lung cancer cells were determined by the TP53 gene status. TP53 wild-type lung cancer cells were effectively inhibited by the combination treatment through p53 activation, while TP53 mutant- or null-type cells exhibited lower sensitivity.ConclusionsThis study, for the first time, established a link between cancer cell genetic features and treatment response to simultaneous SH003 and docetaxel treatment. It highlights the significance of p53 as a predictive factor for susceptibility to this combination treatment. These findings also suggest that p53 status could serve as a crucial criterion in selecting appropriate therapeutic strategies for targeting pyrimidine metabolism in lung cancer.

QiDongNing induces lung cancer cell apoptosis via triggering P53/DRP1-mediated mitochondrial fission.

Non-small-cell lung cancer (NSCLC) is a major cause of worldwide cancer death, posing a challenge for effective treatment. Our previous findings showed that Chinese herbal medicine (CHM) QiDongNing (QDN) could upregulate the expression of p53 and trigger cell apoptosis in NSCLC. Here, our objective was to investigate the mechanisms of QDN-induced apoptosis enhancement. We chose A549 and NCI-H460 cells for validation invitro, and LLC cells were applied to form a subcutaneous transplantation tumour model for validation in more depth. Our findings indicated that QDN inhibited multiple biological behaviours, including cell proliferation, cloning, migration, invasion and induction of apoptosis. We further discovered that QDN increased the pro-apoptotic BAX while inhibiting the anti-apoptotic Bcl2. QDN therapy led to a decline in adenosine triphosphate (ATP) and a rise in reactive oxygen species (ROS). Furthermore, QDN elevated the levels of the tumour suppressor p53 and the mitochondrial division factor DRP1 and FIS1, and decreased the mitochondrial fusion molecules MFN1, MFN2, and OPA1. The results were further verified by rescue experiments, the p53 inhibitor Pifithrin-α and the mitochondrial division inhibitor Mdivi1 partially inhibited QDN-induced apoptosis and mitochondrial dysfunction, whereas overexpression of p53 rather increased the efficacy of the therapy. Additionally, QDN inhibited tumour growth with acceptable safety invivo. In conclusion, QDN induced apoptosis via triggering p53/DRP1-mediated mitochondrial fission in NSCLC cells.

Beta hydroxybutyrate induces lung cancer cell death, mitochondrial impairment and oxidative stress in a long term glucose-restricted condition.

Metabolic plasticity gives cancer cells the ability to shift between signaling pathways to facilitate their growth and survival. This study investigates the role of glucose deprivation in the presence and absence of beta-hydroxybutyrate (BHB) in growth, death, oxidative stress and the stemness features of lung cancer cells. A549 cells were exposed to various glucose conditions, both with and without beta-hydroxybutyrate (BHB), to evaluate their effects on apoptosis, mitochondrial membrane potential, reactive oxygen species (ROS) levels using flow cytometry, and the expression of CD133, CD44, SOX-9, and β-Catenin through Quantitative PCR. The activity of superoxide dismutase, glutathione peroxidase, and malondialdehyde was assessed using colorimetric assays. Treatment with therapeutic doses of BHB triggered apoptosis in A549 cells, particularly in cells adapted to glucose deprivation. The elevated ROS levels, combined with reduced levels of SOD and GPx, indicate that oxidative stress contributes to the cell arrest induced by BHB. Notably, BHB treatment under glucose-restricted conditions notably decreased CD133 expression, suggesting a potential inhibition of cell survival through the downregulation of CD133 levels. Additionally, the simultaneous decrease in mitochondrial membrane potential and increase in ROS levels indicate the potential for creating oxidative stress conditions to impede tumor cell growth in such environmental settings. The induced cell death, oxidative stress and mitochondria impairment beside attenuated levels of cancer stem cell markers following BHB administration emphasize on the distinctive role of metabolic plasticity of cancer cells and propose possible therapeutic approaches to control cancer cell growth through metabolic fuels.

Cymensifin A: a promising pharmaceutical candidate to defeat lung cancer via cellular reactive oxygen species-mediated apoptosis.

Background: The upgrade of natural products for cancer treatment is essential since current anticancer drugs still pose severe side effects. Cymensifin A (Cym A) isolated from an orchid Cymbidium ensifolium has shown its potential to induce the death of several cancer cells; however, its underlying molecular mechanisms are hitherto unknown. Methods: Here, we conducted a set of in vitro preliminary tests to assess the cytotoxic effects of Cym A on non-small-cell lung cancer (NSCLC) cells (A549, H23, H292, and H460). A flow cytometry system and Western blot analyses were employed to unveil molecular mechanisms underlying cancer cell apoptosis caused by Cym A. Results: Cym A at 25-50μM caused the death of all NSCLC cells tested, and its cytotoxicity was comparable to cisplatin, a currently used anticancer drug. The compound induced apoptosis of all NSCLC cells in a dose-dependent manner (5-50μM), proven by flow cytometry, but H460 cells showed more resistance compared to other cells tested. Cym A-treated H460 cells demonstrated increased reactive oxygen species (ROS) and downregulated antioxidants (catalase, superoxide dismutase, and thioredoxin). The compound also upregulated the tumor suppressor P53 and the pro-apoptotic protein BAX but downregulated pro-survival proteins (BCL-2 and MCL-1) and deactivated survival signals (AKT and ERK) in H460 cells. Cym A was proven to trigger cellular ROS formation, but P53 and BAX were 2-fold more activated by Cym A compared to those treated with hydrogen peroxide. Our findings also supported that Cym A exerted its roles in the downregulation of nuclear factor erythroid 2-related factor 2 (a regulator of cellular antioxidant activity) and the increased levels of cleaved poly (ADP-ribose) polymerase (PARP) and cleaved caspase 3/7 during apoptosis. Conclusion: We propose that Cym A induces lung cancer cell death via ROS-mediated apoptosis, while the modulation of cellular ROS/antioxidant activity, the upregulation of P53 and BAX, the downregulation or deactivation of BCL-2, MCL-1, AKT, and ERK, and the increased cleavage of PARP and caspase 3/7, were the elucidated underlying molecular mechanisms of this phytochemical. The compound can be a promising candidate for future anticancer drug development.

Abstract 3053: PTEN as a double-edged sword regulates EGFRL858R-induced lung cancer progression

Abstract Lung cancer is the major cause of death worldwide. Activation of oncogenes or inhibition of tumor suppressors causes cancer formation. Previous studies have indicated that Pten, as a tumor suppressor, inhibits cancer formation. In this study, we studied the role of Pten in EGFRL858R-induced lung cancer in vivo. Interestingly, loss of Pten increased bronchial cell hyperplasia but decreased alveolar cell hyperplasia in EGFRL858R*Pten−/−-induced lung cancer. Syatematic analysis of gene expression by RNA-seq showed that a number of genes related to ciliogenesis were upregulated in EGFRL858R*Pten−/−-induced lung cancer and subsequently showed that bronchial ciliated cells were hyperplastic. Several critical ciliogenesis-related genes, such as mucin5a, DNAI2 and DNAI3, were found to be regulated by NR2F1. Next, NR2F1 was found to be inhibited by overexpression of Pten, indicating that Pten negatively regulates NR2F1, thereby inhibiting the expression of ciliogenesis-related genes and leading to the inhibition of bronchial cell hyperplasia during EGFRL858R-induced lung cancer progression. In addition, we also found that Pten decreased Akt phosphorylation in A549, Kras mutant, and H1299 cells but increased Akt phosphorylation in PC9, EGFRL858R, and H1299L858R cells, suggesting that Pten may function as a tumor suppressor and an oncogene in lung cancers with Kras mutation and EGFR mutation, respectively. PTEN acts as a double-edged sword that differentially regulates EGFRL858R-induced lung cancer progression in different genomic backgrounds. Understanding the Pten in lung cancer with different genetic backgrounds will be beneficial for therapy in the future. Citation Format: Jan-Jong Hung. PTEN as a double-edged sword regulates EGFRL858R-induced lung cancer progression [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 3053.

Abstract 7062: CIP2A enhances mitochondrial respiratory electron transport chain complexes and induces lung cancer in vivo

Abstract Identification of oncogenes that can induce cancer in vivo is critical to elucidation of tumorigenesis and development of targeted therapies. Here, we reported for the first time that forced ectopic expression of CIP2A, the cancerous inhibitor of protein phosphatase 2A (PP2A), in lung tissues induced lung adenocarcinoma in mice. CIP2A upregulated the transcription and translation of mitochondrial DNA (mtDNA), and increases the enzymatic activity of mitochondrial electron transport chain (ETC) complex IV and V, thus enhancing the function of mitochondria and promoting the level of oxidative phosphorylation in tumors. CIP2A inhibited the binding of PP2A-B56α to FOXO3a, leading to the enhancement of the phosphorylation level of FOXO3a. The phosphorylated FOXO3a then translocated into the mitochondrion, and acted as a transcription factor to regulate CIP2A-mediated metabolic reprogramming in cancer cells. We found that oxidative phosphorylation inhibitors effectively inhibited CIP2A-induced cell proliferation. In non-small cell lung cancer, CIP2A level in tumor tissues was positively associated with the level of mtDNA. Our results indicated that CIP2A is able to induce lung adenocarcinoma in mice and has a critical role in mitochondrial oxidative phosphorylation, and represents a promising therapeutic target for non-small cell lung cancer. Competing interests: The authors declare no competing interests. Citation Format: Fu-Ying Yang, Di Wang, Li-Jun liang, Gui-Zhen Wang, Guang-Biao Zhou. CIP2A enhances mitochondrial respiratory electron transport chain complexes and induces lung cancer in vivo [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 7062.

PTEN decreases NR2F1 expression to inhibit ciliogenesis during EGFRL858R-induced lung cancer progression

Lung cancer is the major cause of death worldwide. Activation of oncogenes or inhibition of tumor suppressors causes cancer formation. Previous studies have indicated that PTEN, as a tumor suppressor, inhibits cancer formation. In this study, we studied the role of PTEN in EGFRL858R-induced lung cancer in vivo. Interestingly, loss of PTEN increased bronchial cell hyperplasia but decreased alveolar cell hyperplasia in EGFRL858R*PTEN-/--induced lung cancer. Systematic analysis of gene expression by RNA-seq showed that several genes related to ciliogenesis were upregulated in EGFRL858R*PTEN-/--induced lung cancer and subsequently showed that bronchial ciliated cells were hyperplastic. Several critical ciliogenesis-related genes, such as Mucin5A, DNAI2, and DNAI3, were found to be regulated by NR2F1. Next, NR2F1 was found to be inhibited by overexpression of PTEN, indicating that PTEN negatively regulates NR2F1, thereby inhibiting the expression of ciliogenesis-related genes and leading to the inhibition of bronchial cell hyperplasia during EGFRL858R-induced lung cancer progression. In addition, we also found that PTEN decreased AKT phosphorylation in A549, KRAS mutant, and H1299 cells but increased AKT phosphorylation in PC9, EGFRL858R, and H1299L858R cells, suggesting that PTEN may function as a tumor suppressor and an oncogene in lung cancers with KRAS mutation and EGFR mutation, respectively. PTEN acts as a double-edged sword that differentially regulates EGFRL858R-induced lung cancer progression in different genomic backgrounds. Understanding the PTEN in lung cancer with different genetic backgrounds will be beneficial for therapy in the future.