Apoptosis In Non-small Cell Lung Cancer Cells Research Articles

Xanthohumol overcomes osimertinib resistance via governing ubiquitination-modulated Ets-1 turnover

Non-small cell lung cancer (NSCLC) is a prevalent and fatal malignancy with a significant global impact. Recent advancements have introduced targeted therapies like tyrosine kinase inhibitors (TKIs) such as osimertinib, which have improved patient outcomes, particularly in those with EGFR mutations. Despite these advancements, acquired resistance to TKIs remains a significant challenge. Hence, one of the current research priorities is understanding the resistance mechanisms and identifying new therapeutic targets to improve therapeutic efficacy. Herein, we identified high expression of c-Met in osimertinib-resistant NSCLC cells, and depletion of c-Met significantly inhibited the proliferation of osimertinib-resistant cells and prolonged survival in mice, suggesting c-Met as an attractive therapeutic target. To identify effective anti-tumor agents targeting c-Met, we screened a compound library containing 641 natural products and found that only xanthohumol exhibited potent inhibitory effects against osimertinib-resistant NSCLC cells. Moreover, combination treatment with xanthohumol and osimertinib sensitized osimertinib-resistant NSCLC cells to osimertinib both in vitro and in vivo. Mechanistically, xanthohumol disrupted the interaction between USP9X and Ets-1, and inhibited the phosphorylation of Ets-1 at Thr38, promoting its degradation, thereby targeting the Ets-1/c-Met signaling axis and inducing intrinsic apoptosis in osimertinib-resistant NSCLC cells. Overall, the research highlights the critical role of targeting c-Met to address osimertinib resistance in NSCLC. By demonstrating the efficacy of xanthohumol in overcoming resistance and enhancing therapeutic outcomes, this study provides valuable insights and potential new strategies for improving the clinical management of 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.

Inhibition of Chk1 with Prexasertib Enhances the Anticancer Activity of Ciclopirox in Non-Small Cell Lung Cancer Cells

Lung cancer is a leading cause of cancer-related deaths worldwide. Non-small cell lung cancer (NSCLC) is the most prevalent lung cancer subtype. Ciclopirox olamine (CPX), an off-patent fungicide, has been identified as a new anticancer agent. Prexasertib (PRE), a Chk1 inhibitor, is in phase 1/2 clinical trials in various tumors. The anticancer effect of the combination of CPX with PRE on NSCLC cells is unknown. Here, we show that CPX is synergistic with PRE in inhibiting cell proliferation and inducing apoptosis of NSCLC (A549 and A427) cells. Combined treatment with CPX and PRE significantly increased the cell population in the G1/G0 and sub-G1 phases, compared to the single treatment with CPX or PRE. Concurrently, the combined treatment downregulated the protein levels of cyclins (A, B1), cyclin-dependent kinases 4, 6, 2 (CDK4, CDK6, CDK2), cell division cycle 25 B, C (Cdc25B, Cdc25C), and upregulated the protein levels of the CDK inhibitors p21 and p27, leading to decreased phosphorylation of Rb. In addition, the combined treatment increased DNA damage, evidenced by increased expression of γH2AX. In line with this, the combined treatment induced more apoptosis than either single treatment. This was associated with increased expression of DR4, DR5, Fas, and FADD and decreased expression of survivin, resulting in activation of caspase 8 and caspase 3 as well as cleavage of poly (ADP ribose) polymerase (PARP). Taken together, the results suggest that inhibition of Chk1 with PRE can enhance the anticancer activity of CPX at least partly by decreasing cell proliferation and increasing apoptosis in NSCLC cells.

Hypoxia drives estrogen receptor β-mediated cell growth via transcription activation in non-small cell lung cancer.

Non-small cell lung cancer (NSCLC) is a highly malignant tumor with a poor prognosis. Hypoxia conditions affect multiple cellular processes promoting the adaptation and progression of cancer cells via the activation of hypoxia-inducible factors (HIF) and subsequent transcription activation of their target genes. Preliminary studies have suggested that estrogen receptor β (ERβ) might play a promoting role in the progression of NSCLC. However, the precise mechanisms, particularly its connection to HIF-1α-mediated modulation under hypoxia, remain unclear. Our findings demonstrated that the overexpression of ERβ, not ERα, increased cell proliferation and inhibition of apoptosis in NSCLC cells and xenografts. Tissue microarray staining revealed a strong correlation between the protein expression of HIF-1α and ERβ. HIF-1α induced ERβ gene transcription and protein expression in CoCl2-induced hypoxia, 1% O2 incubation, or HIF-1α overexpressing cells. ChIP identified HIF-1α binding to a hypoxia response element in the ESR2 promoter. The suppression of HIF-1α and ERβ both in vitro and in vivo effectively reduced the tumor growth, thus emphasizing the promising prospects of targeting HIF-1α and ERβ as a therapeutic approach for the treatment of NSCLC. KEY MESSAGES: ERβ, not ERα, increases cell proliferation and inhibition of apoptosis in NSCLC cells and xenografts. A strong correlation exists between the protein expression of HIF-1α and ERβ. HIF-1α induced ERβ gene transcription and protein expression in hypoxic cells via binding to HRE in the ESR2 promoter. The suppression of HIF-1α and ERβ both in vitro and in vivo effectively reduced the NSCLC tumor growth.

EGCG enhances antitumor effect of apatinib in nonsmall cell lung cancer by targeting VEGF signaling to inhibit glycolysis.

Nonsmall cell lung cancer (NSCLC), one of the most aggressive malignancies globally, is characterized by poor prognosis and limited life expectancy. Epigallocatechin-3-gallate (EGCG), a natural polyphenol found in green tea, has emerged as a promising anticancer agent due to its potent antitumor properties. However, the role and the underlying mechanisms of EGCG in NSCLC remain poorly understood. Hence, this research aimed to explore the effect of EGCG on the antitumor effect of apatinib in NSCLC throughvascular endothelial growth factor(VEGF)-regulated glycolysis. Cell Counting Kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine staining, wound healing, transwell, terminal deoxynucleotidyl transferase dUTP nick-end labeling, and flow cytometry assays were carried out to evaluate the proliferation, migration, invasion, and apoptosis of H1299 cells, respectively. Furthermore, western blot analysis was used to detect the expressions of VEGF, p-vascular endothelial growth factor receptor-2, hypoxia-inducible factor 1α, neuropilin-1, phosphorylated-phosphatidylinositol 3-kinase, and phosphorylated-AKT. The transfection efficiency of H1299 cells with VEGF overexpression plasmid was also assessed by western blot analysis. Glycolysis was analyzed by estimating extracellular acidification rate, lactate concentration, glucose uptake, and the expressions of lactate dehydrogenase A, pyruvate kinase M2, and hexokinase 2. The results demonstrated that VEGF activated glycolysis in NSCLC cells. EGCG alone and apatinib alone or in combination inhibited cell viability, proliferation, invasion, migration, and glycolysis whereas promoted apoptosis in NSCLC cells. EGCG regulated glycolysis levels in NSCLC through VEGF overexpression, and enhanced the antitumor effect of apatinib in NSCLC through VEGF-regulated glycolysis. Taken together, EGCG strengthened the protective effects of apatinib in NSCLC through glycolysis mediated by VEGF.

Network Pharmacology and in vitro Experimental Verification on Intervention of Oridonin on Non-Small Cell Lung Cancer.

To explore the key target molecules and potential mechanisms of oridonin against non-small cell lung cancer (NSCLC). The target molecules of oridonin were retrieved from SEA, STITCH, SuperPred and TargetPred databases; target genes associated with the treatment of NSCLC were retrieved from GeneCards, DisGeNET and TTD databases. Then, the overlapping target molecules between the drug and the disease were identified. The protein-protein interaction (PPI) was constructed using the STRING database according to overlapping targets, and Cytoscape was used to screen for key targets. Molecular docking verification were performed using AutoDockTools and PyMOL software. Using the DAVID database, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were conducted. The impact of oridonin on the proliferation and apoptosis of NSCLC cells was assessed using cell counting kit-8, cell proliferation EdU image kit, and Annexin V-FITC/PI apoptosis kit respectively. Moreover, real-time quantitative PCR and Western blot were used to verify the potential mechanisms. Fifty-six target molecules and 12 key target molecules of oridonin involved in NSCLC treatment were identified, including tumor protein 53 (TP53), Caspase-3, signal transducer and activator of transcription 3 (STAT3), mitogen-activated protein kinase kinase 8 (MAPK8), and mammalian target of rapamycin (mTOR). Molecular docking showed that oridonin and its key target molecules bind spontaneously. GO and KEGG enrichment analyses revealed cancer, apoptosis, phosphoinositide-3 kinase/protein kinase B (PI3K/Akt), and other signaling pathways. In vitro experiments showed that oridonin inhibited the proliferation, induced apoptosis, downregulated the expression of Bcl-2 and Akt, and upregulated the expression of Caspase-3. Oridonin can act on multiple targets and pathways to exert its inhibitory effects on NSCLC, and its mechanism may be related to upregulating the expression of Caspase-3 and downregulating the expressions of Akt and Bcl-2.

Homoharringtonine promotes non-small-cell lung cancer cell death via modulating HIF-1α/ERβ/E2F1 feedforward loop.

Hypoxia conditions promote the adaptation and progression of non-small-cell lung cancer (NSCLC) via hypoxia-inducible factors (HIF). HIF-1α may regulate estrogen receptor β (ERβ) and promote the progression of NSCLC. The phytochemical homoharringtonine (HHT) exerts strong inhibitory potency on NSCLC, with molecular mechanism under hypoxia being elusive. The effects of HHT on NSCLC growth were determined by cell viability assay, colony formation, flow cytometry, and H460 xenograft models. Western blotting, molecular docking program, site-directed mutagenesis assay, immunohistochemical assay, and immunofluorescence assay were performed to explore the underlying mechanisms of HHT-induced growth inhibition in NSCLC. HIF-1α/ERβ signaling-related E2F1 is highly expressed and contributes to unfavorable survival and tumor growth. The findings in hypoxic cells, HIF-1α overexpressing cells, as well as ERβ- or E2F1-overexpressed and knockdown cells suggest that the HIF-1α/ERβ/E2F1 feedforward loop promotes NSCLC cell growth. HHT suppresses HIF-1α/ERβ/E2F1 signaling via the ubiquitin-proteasome pathway, which is dependent on the inhibition of the protein expression of HIF-1α and ERβ. Molecular docking and site-directed mutagenesis revealed that HHT binds to the GLU305 site of ERβ. HHT inhibits cell proliferation and colony formation and promotes apoptosis in both NSCLC cells and xenograft models. The formation of the HIF-1α/ERβ/E2F1 feedforward loop promotes NSCLC growth and reveals a novel molecular mechanism by which HHT induces cell death in NSCLC.

SLC12A8 promotes the migration and invasion of non-small cell lung cancer (NSCLC) cells.

This study aims to investigate the impacts of SLC12A8 on the invasion, migration, and epithelial-mesenchymal transition (EMT) of non-small cell lung cancer (NSCLC) cells. GEPIA database was employed to examine SLC12A8 expression pattern in lung cancer cells. Subsequently, qRT-PCR and Western blot analyses were conducted to assess SLC12A8 expression in NSCLC tissues and cell lines. The overall prognosis of NSCLC patients was evaluated using Kaplan-Meier plot and univariate and multivariate COX regression curves. The knockdown of SLC12A8 was established using lentivirus-mediated shRNA in A549 and H1299 cells. Cell proliferation, invasion, migration, and apoptosis were evaluated using CCK-8 assay, transwell, and flow cytometry techniques, respectively. Western blot analysis was performed to measure the expression levels of EMT-related proteins (E-cadherin and vimentin). The expression level of SLC12A8 was found to be significantly higher in both NSCLC cell lines and tissues. High SLC12A8 expression was correlated with a poor prognosis in NSCLC patients. Knocking down SLC12A8 led to a significant decrease in proliferation, migration, and invasion abilities, while promoting apoptosis in NSCLC cells. Additionally, SLC12A8 knockdown resulted in decreased levels of N-cadherin and vimentin, along with increased E-cadherin expression. The results indicate that reducing SLC12A8 expression may suppress the malignant phenotype of NSCLC cells, as well as the EMT. SLC12A8 may serve as a target for the clinical management of NSCLC progression.

SIRT1 silencing ameliorates malignancy of non-small cell lung cancer via activating FOXO1

Non-small cell lung cancer (NSCLC), being the most prevalent and lethal malignancy affecting the lungs, poses a significant threat to human health. This research aims at illustrating the precise role and related mechanisms of silent information regulator type-1 (SIRT1) in NSCLC progression. The expression pattern of SIRT1 in NSCLC cell lines was examined using quantitative real-time polymerase chain reaction and western blotting. Functional assays in NSCLC cell lines validated the biological capabilities of SIRT1 on malignant phenotypes, and its impact on tumorigenicity was further evaluated in vivo. In addition, the FOXO1 inhibitor AS1842856 was applied to verify the role of SIRT1 on FOXO pathway in vitro. SIRT1 expression was prominently elevated in NSCLC cell lines. The depletion of SIRT1 retarded the capabilities of proliferation, migration and invasion, while enhancing apoptosis in NSCLC cells. Furthermore, SIRT1 silencing restricted the tumorigenesis of NSCLC in vivo. Additionally, AS1842856 treatment ameliorated the inhibitory effect of SIRT1 deficiency on malignant phenotypes in NSCLC cells. SIRT1 deletion exerted an anti-oncogenic role in NSCLC via activation of FOXO1.

Inhibiting the Otub1/phosphorylated STAT3 axis for the treatment of non-small cell lung cancer.

The transcription factor STAT3 is a promising target for the treatment of non-small cell lung cancer (NSCLC). STAT3 activity is mainly dependent on phosphorylation at tyrosine 705 (pSTAT3-Y705), but the modulation on pSTAT3-Y705 is elusive. By screening a library of deubiquitinases (Dubs), we found that the Otub1 increasesSTAT3 transcriptional activity. As a Dub, Otub1 binds to pSTAT3-Y705 and specifically abolishes its K48-linked ubiquitination, therefore preventing its degradation and promoting NSCLC cell survival. The Otub1/pSTAT3-Y705 axis could be a potential target for the treatment of NSCLC. To explore this concept, we screen libraries of FDA-approved drugs and natural products based on STAT3-recognition element-driven luciferase assay, from which crizotinib is found to block pSTAT3-Y705 deubiquitination and promotes its degradation. Different from its known action to induce ALK positive NSCLC cell apoptosis, crizotinib suppresses ALK-intact NSCLC cell proliferation and colony formation but not apoptosis. Furthermore, crizotinib also suppresses NSCLC xenograft growth in mice. Taken together, these findings identify Otub1 as the first deubiquitinase of pSTAT3-Y705 and provide that the Otub1/pSTAT3-Y705 axis is a promising target for the treatment of NSCLC.

Distinct Amino Acid-Based PROTACs Target Oncogenic Kinases for Degradation in Non-Small Cell Lung Cancer (NSCLC).

Proteolysis-targeting chimeras (PROTACs) selectively eliminate detrimental proteins by exploiting the ubiquitin-proteasome system (UPS), representing a promising therapeutic strategy against various diseases. Effective adaptations of degradation signal sequences and E3 ligases for PROTACs remain limited. Here, we employed three amino acids─Gly, Pro, and Lys─as the ligand to recruit the corresponding E3 ligases: CRL2ZYG11B/ZER1, GID4, and UBRs, to degrade EML4-ALK and mutant EGFR, two oncogenic drivers in NSCLC. We found that the extent of EML4-ALK and EGFR reduction can be easily fine-tuned by using different degradation signals. These amino acid-based PROTACs, termed AATacs, hindered proliferation and induced cell cycle arrest and apoptosis of NSCLC cells in vitro. Compared to other PROTACs, AATacs are small, interchangeable but with different degradation efficiency. Our study further expands the repertoire of E3 ligases and their ligands for PROTAC application, improving the versatility and utility of targeted protein degradation for therapeutic purposes.

Circular RNA NFIX Functions as an Oncogene in Non-Small Cell Lung Cancer by Modulating the miR-214-3p/TRIAP1 Axis.

circRNA NFIX has been shown to exist as an oncogene in glioma. But its expression and role in NSCLC (non-small cell lung cancer) are still unclear. This research aimed to discover the expression and function of circRNA NFIX in NSCLC. In this research, qRT-PCR was utilized to investigate the expression levels of circRNA NFIX, miRNA-214-3p, and TRIAP1 in NSCLC tissues and cell lines. The binding sites between circRNA NFIX/TRIAP1 and miRNA-214-3p were predicted using the Starbase. These interactions were further validated using a double luciferase reporter assay. Cell proliferation and apoptosis were assessed through MTT and flow cytometry, respectively. The expression of apoptosis-related proteins was measured by western blot assay. miRNA-214-3p could link with circRNA NFIX. circRNA NFIX was upregulated, while miRNA-214-3p was downregulated in NSCLC cell lines and clinical samples. Besides, suppression of circRNA NFIX repressed cell proliferation and induced apoptosis in NSCLC cells by upregulating miRNA-214-3p expression. Besides, the data indicated that TRIAP1 was a target of miRNA-214-3p, and it was negatively regulated by miRNA-214-3p in NSCLC cells. The excessive expression of miRNA-214-3p suppressed NSCLC cell proliferation and increased apoptosis. In addition, overexpression of TRIAP1 significantly reversed the effects on NSCLC cells caused by miRNA-214-3p mimic. circRNA NFIX silencing repressed the proliferation of NSCLC cells and induced cell apoptosis by regulating the miR-214-3p/TRIAP1 axis, which was a potential diagnostic and therapeutic target for NSCLC.

METTL3/IGF2BP1 influences the development of non-small-cell lung cancer by mediating m6A methylation modification of TRPV1.

Methyltransferase 3 (METTL3) accelerates N6-methyladenosine (m6A) modifications and affects cancer progression, including non-small-cell lung cancer (NSCLC). In this study, we aimed to explore the regulatory mechanisms of METTL3 underling NSCLC. Immunohistochemical assay, quantitative real-time polymerase chain reaction (qRT-PCR)assay, and western blot assay were conducted for gene expression. MTT assay and colony formation assay were performed to explore cell proliferation capacity. Cell apoptosis and THP-1 cell polarization were estimated by flow cytometry analysis. Cell migration and invasion capacities were evaluated by transwell assay. Methylated RNA immunoprecipitation assay, dual-luciferase reporter assay, actinomycin D treatment and RIP assay were performed to analyze the relationships of METTL3, insulin-like growth factor 2 mRNA binding protein 1 (IGF2BP1), and transient receptor potential cation channel subfamily V member 1 (TRPV1). The functions of METTL3 and TRPV1 in vivo were investigated through establishing the murine xenograft model. TRPV1 expression was upregulated in NSCLC and related poor prognosis. TRPV1 silencing inhibited NSCLC cell growth and metastasis, induced NSCLC cell apoptosis, and repressed M2 macrophage polarization. The results showed that METTL3 and IGF2BP1 could regulate TRPV1 expression through m6A methylation modification. Moreover, METTL3 deficiency inhibited NSCLC cell growth, metastasis, and M2 macrophage polarization and facilitated NSCLC cell apoptosis, while TRPV1 overexpression restored the impacts. In addition, METTL3 knockdown restrained tumor growth in vivo via regulating TRPV1 expression. METTL3 bound to IGF2BP1 and enhanced IGF2BP1's m6A recognition of TRPV1 mRNA, thereby promoting NSCLC cell growth and metastasis, and inhibiting M2 macrophage polarization.

Role of SFRP5 in Non-Small Cell Lung Cancer and Its Correlation with SUV of 18F-FDG PET-CT

Aim: This study aimed to evaluate the relationship between secreted frizzled-related protein 5 (SFRP5) expression and fluorine 18-fluoro-deoxyglucose (18 F-FDG) uptake imaged with positron emission tomography/tomography (PET/CT) in patients with non-small cell lung cancer (NSCLC). In addition, we sought to elucidate the potential role and mechanism of action of SFRP5 in NSCLC.Materials and methods: The maximum standardized uptake value (SUVmax) of the lesions was calculated. SFRP5 expression was analyzed using quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). The correlation between SFRP5 expression and SUVmax was evaluated using Pearson’s correlation analysis. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), flow cytometry, wound healing, and transwell assays were used to analyze cell viability, apoptosis, migration, and invasion, respectively.Results and conclusion: The results indicated that the SUVmax was higher in patients with NSCLC than that in healthy volunteers. Moreover, SFRP5 expression was lower in tissues from the four types of NSCLC than that in the adjacent normal tissues. SUVmax negatively correlated with SFRP5 expression in the four types of NSCLC. In addition, up-regulation of SFRP5 decreased the viability, migration, and invasion abilities, and increased apoptosis of NSCLC cells. Furthermore, SFRP5 inhibited the Wnt/β-catenin pathway in NSCLC cells. In conclusion, SFRP5 modulates the biological behaviors of NSCLC through Wnt/β-catenin pathway.

Novel EGFR inhibitors against resistant L858R/T790M/C797S mutant for intervention of non-small cell lung cancer

To overcome C797S mutation, the latest and most common resistance mechanism in the clinical treatment of third-generation EGFR inhibitor, a novel series of substituted 6-(2-aminopyrimidine)-indole derivatives were designed and synthesized. Through the structure-activity relationship (SAR) study, compound 11eg was identified as a novel and potent EGFR L858R/T790M/C797S inhibitor (IC50 = 0.053 μM) but had a weak effect on EGFRWT (IC50 = 1.05 μM). 11eg significantly inhibited the proliferation of the non-small cell lung cancer (NSCLC) cells harboring EGFRL858R/T790M/C797S with an IC50 of 0.052 μM. 11eg also showed potent inhibitory activity against other NSCLC cell lines harboring main EGFR mutants. Furthermore, 11eg exhibited much superior activity in arresting cell cycle and inducing apoptosis of NSCLC cells with mutant EGFRC797S. It blocked cellular EGFR signaling. Importantly, 11eg markedly suppressed the tumor growth in in vivo xenograft mouse model with good safety. Additionally, 11eg displayed good microsomal stability. These results demonstrated the potential of 11eg with novel scaffold as a promising lead compound targeting EGFRC797S to guide in-depth structural optimization.

Hypoxia-enhanced YAP1-EIF4A3 interaction drives circ_0007386 circularization by competing with CRIM1 pre-mRNA linear splicing and promotes non-small cell lung cancer progression

BackgroundThe progression of non-small cell lung cancer (NSCLC) is significantly influenced by circular RNAs (circRNAs), especially in tumor hypoxia microenvironment. However, the precise functions and underlying mechanisms of dysregulated circRNAs in NSCLC remain largely unexplored.MethodsDifferentially expressed circRNAs in NSCLC tissues were identified through high-throughput RNA sequencing. The characteristics of circ_0007386 were rigorously confirmed via Sanger sequencing, RNase R treatment and actinomycin D treatment. The effects of circ_0007386 on proliferation and apoptosis were investigated using CCK8, cloning formation assays, TUNEL staining, and flow cytometry assays in vitro. In vivo, xenograft tumor models were used to evaluate its impact on proliferation. Mechanistically, the regulatory relationships of circ_0007386, miR-383-5p and CIRBP were examined through dual luciferase reporter assays and rescue experiments. Additionally, we detected the binding of EIF4A3 to CRIM1 pre-mRNA by RNA immunoprecipitation and the interaction between YAP1 and EIF4A3 under hypoxic conditions by co-immunoprecipitation.ResultsOur investigation revealed a novel circRNA, designated as circ_0007386, that was upregulated in NSCLC tissues and cell lines. Circ_0007386 modulated proliferation and apoptosis in NSCLC both in vitro and in vivo. Functionally, circ_0007386 acted as a sponge for miR-383-5p, targeting CIRBP, which influenced NSCLC cell proliferation and apoptosis via the PI3K/AKT signaling pathway. Furthermore, under hypoxic conditions, the interaction between YAP1 and EIF4A3 was enhanced, leading to the displacement of EIF4A4 from binding to CRIM1 pre-mRNA. This facilitated the back-splicing of CRIM1 pre-mRNA, increasing the formation of circ_0007386. The circ_0007386/miR-383-5p/CIRBP axis was significantly associated with the clinical features and prognosis of NSCLC patients.ConclusionsCirc_0007386, regulated by YAP1-EIF4A3 interaction under hypoxia conditions, plays an oncogenic role in NSCLC progression via the miR-383-5p/CIRBP axis.

LncRNA SH3PXD2A-AS1 facilitates cisplatin resistance in non-small cell lung cancer by regulating FOXM1 succinylation

BackgroundLong noncoding RNAs (lncRNAs) play vital regulatory functions in non-small cell lung cancer (NSCLC). Cisplatin (DDP) resistance has significantly decreased the effectiveness of DDP-based chemotherapy in NSCLC patients. This study aimed to investigate the effects of SH3PXD2A antisense RNA 1 (SH3PXD2A-AS1) on DDP resistance in NSCLC.MethodsProliferation and apoptosis of DDP-resistant NSCLC cells were detected using cell counting kit-8 and flow cytometry assays. The interaction between SH3PXD2A-AS1 and sirtuin 7 (SIRT7) was assessed using co-immunoprecipitation (Co-IP), RNA pull-down, RNA immunoprecipitation (RIP), RNA fluorescence in situ hybridization, and immunofluorescence assays, while succinylation (SUCC) of Forkhead Box M1 (FOXM1) was analyzed by IP and Western blot assays. The role of SH3PXD2A-AS1 in vivo was explored using a xenografted tumor model.ResultsExpression of SH3PXD2A-AS1 was found elevated in DDP-resistant NSCLC cells, while it’s knocking down translated into suppression of cell viability and promotion of apoptosis. Moreover, silencing of SH3PXD2A-AS1 resulted in decreased FOXM1 protein level and enhanced FOXM1-SUCC protein level. The SIRT7 was found to interact with FOXM1, translating into inhibition of FOXM1 SUCC at the K259 site in human embryonic kidney (HEK)-293T cells. Overexpressing of SIRT7 reversed the increase of FOXM1-SUCC protein level and apoptosis, and the decrease of cell viability induced by silencing of SH3PXD2A-AS1. In tumor-bearing mice, SH3PXD2A-AS1 inhibition suppressed tumor growth and the protein levels of Ki67, SIRT7, and FOXM1.ConclusionSH3PXD2A-AS1 promoted DDP resistance in NSCLC cells by regulating FOXM1 SUCC via SIRT7, offering a promising therapeutic approach for NSCLC.

YTH domain family protein 3 accelerates non-small cell lung cancer immune evasion through targeting CD8+ T lymphocytes

Immune evasion is one of the critical hallmarks of malignant tumors, especially non-small cell lung cancer (NSCLC). Emerging findings have illustrated the roles of N6-methyladenosine (m6A) on NSCLC immune evasion. Here, this study investigated the function and underlying mechanism of m6A reader YTH domain family protein 3 (YTHDF3) on NSCLC immune evasion. YTHDF3 was found to be highly expressed in NSCLC tissue and act as an independent prognostic factor for overall survival. Functionally, up-regulation of YTHDF3 impaired the CD8+ T antitumor activity to deteriorate NSCLC immune evasion, while YTHDF3 silencing recovered the CD8+ T antitumor activity to inhibit immune evasion. Besides, YTHDF3 up-regulation reduced the apoptosis of NSCLC cells. Mechanistically, PD-L1 acted as the downstream target for YTHDF3, and YTHDF3 could upregulate the transcription stability of PD-L1 mRNA. Overall, YTHDF3 targeted PD-L1 to promote NSCLC immune evasion partially through escaping effector cell cytotoxicity CD8+ T mediated killing and antitumor immunity. In summary, this study provides an essential insight for m6A modification on CD8+ T cell-mediated antitumor immunity in NSCLC, which might inspire an innovation for lung cancer tumor immunotherapy.

Incense-burning smoke ingredient Auramine enhances lincRNA-p21 expression for chemosensitization in p53-mutated non-small cell lung cancer

Incense-burning smoke is a deleterious air pollutant that initiates cytotoxic effects by inducing apoptosis in lung epithelial cells and also acts as a risk factor for lung cancers. Auramine, an ingredient of incense smoke, has been implicated in tumor progression and cellular sensitivity in non-small cell lung cancer (NSCLC) towards anti-cancer agents through unclear mechanisms. Tumor protein p53 (TP53)-activated long intergenic non-coding RNA-p21 (lincRNA-p21) undertakes a pivotal role in regulating cell apoptosis and chemosensitivity. TP53 mutations prevalent in 50% of NSCLC, contribute to diminished therapeutic efficacy. However, the influence of auramine on chemotherapy-induced lincRNA-p21 expression and apoptosis in NSCLC with different TP53 genetic statuses remains unexplored. This study disclosed that both wild-type p53 (wtp53) and mutant p53 (mutp53) mediate lincRNA-p21 expression, albeit through distinct promoter enhancers, p53-response element (p53RE) and non-B DNA structure G-quadruplex (GQ), respectively. Intriguingly, auramine functions as an effective stabilizer of the GQ structure, augmenting mutp53-mediated lincRNA-p21 expression and enhancing apoptosis and cellular sensitivity to chemotherapy in mutp53-expressing NSCLC cells. These findings suggest a mechanism by which mutp53, in the presence of auramine, is endowed with tumor-suppressing function akin to wtp53, thereby aiding in combating chemoresistance in NSCLC cells harboring TP53 mutations.

Sponge-derived alkaloid AP-7 as a sensitizer to cisplatin in the treatment of multidrug-resistant NSCLC via Chk1-dependent mechanisms.

Multidrug resistance is a substantial obstacle in treating non-small cell lung cancer (NSCLC) with therapies like cisplatin (DDP)-based adjuvant chemotherapy and EGFR-tyrosine kinase inhibitors (TKIs). Aaptamine-7 (AP-7), a benzonaphthyridine alkaloid extracted from Aaptos aaptos sponge, has been shown to exhibit a broad spectrum of anti-tumor activity. However, the anti-cancer activity of AP-7 in combination with DDP and its molecular mechanisms in multidrug-resistant NSCLC are not yet clear. Our research indicates that AP-7 bolsters the growth inhibition activity of DDP on multidrug-resistant NSCLC cells. AP-7 notably disrupts DDP-induced cell cycle arrest and amplifies DDP-induced DNA damage effects in these cells. Furthermore, the combination of AP-7 and DDP downregulates Chk1 activation, interrupts the DNA damage repair-dependent Chk1/CDK1 pathway, and helps to overcome drug resistance and boost apoptosis in multidrug-resistant NSCLC cells and a gefitinib-resistant xenograft mice model. In summary, AP-7 appears to enhance DDP-induced DNA damage by impeding the Chk1 signaling pathway in multidrug-resistant NSCLC, thereby augmenting growth inhibition, both in vitro and in vivo. These results indicate the potential use of AP-7 as a DDP sensitizer in the treatment of multidrug-resistant NSCLC.