Non-small Cell Lung Cancer Tissues Research Articles

Tumor-suppressive miR-4732-3p is sorted into fucosylated exosome by hnRNPK to avoid the inhibition of lung cancer progression

BackgroundAberrant fucosylation observed in cancer cells contributes to an augmented release of fucosylated exosomes into the bloodstream, where miRNAs including miR-4732-3p hold promise as potential tumor biomarkers in our pilot study. However, the mechanisms underlying the sorting of miR-4732-3p into fucosylated exosomes during lung cancer progression remain poorly understood.MethodsA fucose-captured strategy based on lentil lectin-magnetic beads was utilized to isolate fucosylated exosomes and evaluate the efficiency for capturing tumor-derived exosomes using nanoparticle tracking analysis (NTA). Fluorescence in situ hybridization (FISH) and qRT-PCR were performed to determine the levels of miR-4732-3p in non-small cell lung cancer (NSCLC) tissue samples. A co-culture system was established to assess the release of miRNA via exosomes from NSCLC cells. RNA immunoprecipitation (RIP) and miRNA pull-down were applied to validate the interaction between miR-4732-3p and heterogeneous nuclear ribonucleoprotein K (hnRNPK) protein. Cell functional assays, cell derived xenograft, dual-luciferase reporter experiments, and western blot were applied to examine the effects of miR-4732-3p on MFSD12 and its downstream signaling pathways, and the impact of hnRNPK in NSCLC.ResultsWe enriched exosomes derived from NSCLC cells using the fucose-captured strategy and detected a significant upregulation of miR-4732-3p in fucosylated exosomes present in the serum, while its expression declined in NSCLC tissues. miR-4732-3p functioned as a tumor suppressor in NSCLC by targeting 3'UTR of MFSD12, thereby inhibiting AKT/p21 signaling pathway to induce cell cycle arrest in G2/M phase. NSCLC cells preferentially released miR-4732-3p via exosomes instead of retaining them intracellularly, which was facilitated by the interaction of miR-4732-3p with hnRNPK protein for selective sorting into fucosylated exosomes. Moreover, knockdown of hnRNPK suppressed NSCLC cell proliferation, with the elevated levels of miR-4732-3p in NSCLC tissues but the decreased expression in serum fucosylated exosomes.ConclusionsNSCLC cells escape suppressive effects of miR-4732-3p through hnRNPK-mediated sorting of them into fucosylated exosomes, thus supporting cell malignant properties and promoting NSCLC progression. Our study provides a promising biomarker for NSCLC and opens a novel avenue for NSCLC therapy by targeting hnRNPK to prevent the "exosome escape" of tumor-suppressive miR-4732-3p from NSCLC cells.

Role of COX-2/PGE2/EP4 Axis-induced Macrophage Functional Activation in NSCLC Development

Tumor microenvironment (TME) is one of the important factors in tumorigenesis and progression, in which tumor-associated macrophages (TAMs) play an important role in non-small cell lung cancer (NSCLC) progression. However, the mechanism of TAMs in NSCLC progression remains unclear, so this study aimed to investigate the role of TAMs in NSCLC progression and to find potential therapeutic targets. Gene Expression Profiling Interactive Analysis (GEPIA) database was used to analyze the expression of prostaglandin E2 receptor 4 (EP4) mRNA in NSCLC and normal lung tissues; the protein expression levels of cyclooxygenase-2 (COX-2), EP4, cluster of differentiation 86 (CD86), CD163 and CD31 were detected by immunohistochemistry (IHC) in 120 NSCLC tissues and 24 paracancerous tissues specimens. The nude mouse lung adenocarcinoma cell A549 and macrophage RAW264.7 co-transplanted tumor model was established. And the samples were collected by gavage with EP4 inhibitor E7046, and then stained with hematoxylin-eosin (HE), IHC, and immunofluorescence (IF), and then detected by Western blot for the epithelial mesenchymal transformation (EMT) of the tumor tissues of the nude mice in each group. Western blot was used to detect the expressions of EMT related protiens in each group of nude mice; full-length transcriptome sequencing was used to screen the key genes causing liver metastasis and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis was performed. EP4 mRNA expression level in NSCLC tissues was generally lower than that in normal lung tissues (P<0.05); COX-2, EP4, CD163, CD31 proteins were differentially expressed in NSCLC tissues and adjacent tissues, and differences were observed in many clinicopathological parameters of NSCLC patients; RAW264.7 shortened the latency period of tumorigenesis of A549 and promoted the proliferation of tumors and liver metastasis of tumors, and E7046 could reduce tumor cell proliferation activity, tumor tissue vascular density and M2-type macrophage infiltration in nude mice; IF staining showed that macrophages were mainly distributed around the metastatic foci of tumors; Western blot results showed that compared with A549 alone transplantation group, the relative expression of E-cadherin protein in tumor tissues of mice in A549 and RAW264.7 co-transplantation group was significantly decreased, and the difference was statistically significant (P<0.05), while the relative expression of N-cadherin protein was up-regulated, but the difference was not statistically significant (P>0.05); the main pathways enriched in the differential genes of the full-length transcriptome were the PI3K-AKT and MAPK signaling pathways. During NSCLC development, the COX-2/PGE2/EP4 axis may promote tumor progression by inducing macrophage functional activation, and EP4 may be a potential new target for tumor immunotherapy. This study provides new perspectives and ideas for in-depth exploration of the mechanisms of NSCLC development, as well as a theoretical basis for the development of new therapeutic strategies for NSCLC.

BIRC3-HSP90B1 Interaction Inhibits Non-Small Cell Lung Cancer Progression through the Extracellular Signal-Regulated Kinase Pathway.

The long-term prognosis of nonsmall cell lung cancer (NSCLC) remains unsatisfactory, which is a major challenge in lung cancer treatment. BIRC3 is an inhibitor of apoptosis (IAP) protein that contributes to tumor regulation. However, the underlying regulatory mechanisms of BIRC3 in NSCLC remains unknown. We initiated an analysis of BIRC3 expression data in NSCLC tumors and adjacent tissues using the TCGA and GEO databases and examined the variations in prognosis. Further, we conducted overexpression (OE) and knockdown (KD) studies on BIRC3 to evaluate its effects on NSCLC cell proliferation, migration, and invasion. Additionally, through utilization of a nude mouse model, the regulatory effects of BIRC3 on NSCLC were verified in vivo. Co-immunoprecipitation (Co-IP) assay served to pinpoint the proteins with which BIRC3 interacts. The results indicated that BIRC3 is down-regulated in NSCLC tissues and that patients with high BIRC3 expression demonstrate a better prognosis. BIRC3 is a tumor suppressor, inhibiting the proliferation and metastasis of NSCLC. Co-IP results revealed that BIRC3 interacts with HSP90B1, leading to a decrease in HSP90B1 expression and subsequent negative regulation of the ERK signaling pathway. BIRC3 may serve as a prognostic biomarker for NSCLC. It directly interacts with HSP90B1 to negatively regulate the ERK signaling pathway, thereby hindering the progression of NSCLC.

Molecular characteristics of non-small cell lung cancer tissue based on quantitative indicators of progesterone receptors expression

Background. Progesterone receptors (PR) are regulators of cell proliferation and therefore can be considered as an aim for targeted medications in the treatment of oncological diseases. At the same time, a quantitative assessment of PR expression in the tissue of non-small cell lung cancer (NSCLC), which has not yet been carried out in other studies, will determine the possibility of using PR modulators for the treatment of this disease and identify the potential category of patients most susceptible to these drugs.Purpose. To characterize NSCLC by quantitative indicators of PR expression and to determine the correlation of clinically significant characteristics of patients and clinical and morphological parameters of a NSCLC tumor with the PR expression to assess the possibility of using PR modulators in the treatment of this disease.Methods. The PR expression in 130 surgical samples of NSCLC was quantified using an immunofluorescence method associated with flow cytometry. Primary antibodies to PR (NBP2-46388) and secondary antibodies conjugated with DyLight650 (ab98729) were used.Results. The expression of progesterone receptors was detected in all the studied tumors; an abnormal distribution of the marker expression level was noted (P=0.01). The mean expression level was 55.3±16.2%, and the median was 57% with a range of 70%, which indicates heterogeneity of PR expression in tumors of different patients. There were no statistically significant differences in the level of PR expression depending on the histotype and stage of NSCLC, as well as on the sex of patients. At the same time, the level of expression and the frequency of overexpression of PR (&gt;67%) in tumors in non-smoking patients are higher than in smokers (P⩽0.02).Conclusion. The high frequency of occurrence and level of PR expression in NSCLC indicate the possible effectiveness of the use of their modulators in the treatment of this disease, especially in non-smoking patients.

P300 reduces TUBB4B expression to facilitate the biological process of migration and invasion of non-small cell lung cancer cells

This article explored the mechanism of E1A binding protein p300 (P300) and beta-tubulin 4B isotype-encoding gene (TUBB4B) in regulating the migration and invasion of non-small cell lung cancer (NSCLC) cells. TUBB4B and P300 expression in NSCLC tissues and cells was monitored by real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and Western blot. TUBB4B function on NSCLC cell migration, invasion and epithelial-mesenchymal transition (EMT) was monitored by wound healing assay, Transwell experiment and Western blot. The regulation of P300 on TUBB4B was monitored by qRT-PCR and Western blot. Mechanism of P300 and TUBB4B in regulating NSCLC cell migration and invasion was explored by rescue experiment. A xenograft tumor model was established by using nude mouse. As a result, low TUBB4B expression and high P300 expression was discovered in NSCLC tissues and cells. TUBB4B and P300 expression showed a negative correlation in NSCLC tissues. Lower TUBB4B but higher P300 was observed in tumor tissues of NSCLC patients with metastasis. TUBB4B overexpression suppressed NSCLC cell migration, invasion and EMT. TUBB4B silencing had opposite results. P300 overexpression inhibited TUBB4B expression, and P300 silencing facilitated TUBB4B overexpression in NSCLC cells. TUBB4B overexpression counteracted the promotion of P300 overexpression on NSCLC cell invasion and migration. TUBB4B silencing abrogated the inhibition of P300 knockdown on NSCLC cell invasion and migration. TUBB4B overexpression suppressed NSCLC cell in vivo growth. Thus, TUBB4B could be reduced by P300 in NSCLC. It exerted suppression role on NSCLC cell migration, invasion and EMT. TUBB4B may be a novel target for NSCLC treatment.

Photodynamic therapy upregulates expression of HIF-1α and PD-L1 in related pathways and its clinical relevance in non-small-cell lung cancer

BackgroundPhotodynamic therapy (PDT) is a promising interventional treatment approach that contributes to antitumor immunity. It has been reported that PDT can enhance the effectiveness of immune checkpoint inhibitors (ICIs), but its mechanism is yet unclear. Herein, we implemented bioinformatics analysis to detect common pathways and potential biomarkers in non-small cell lung cancer (NSCLC), PDT, and NSCLC immunotherapy to investigate potential links between PDT, immunotherapy and NSCLC, and their clinical impact.MethodsDifferentially expressed genes in NSCLC- and NSCLC immunotherapy-related data in the GEO database were intersected with PDT-related genes in the GeneCards database to obtain candidate genes and shared pathways. Enrichment analysis and protein–protein interaction were established to identify key genes in functionally enriched pathways. The expression profiles and the prognostic significance of key genes were depicted.ResultsBioinformatics analysis showed that HIF-1α was screened as a prognostic gene in hypoxia, HIF-1, and PD-L1-related signaling pathways, which was associated with clinical response in NSCLC patients after PDT and immunotherapy. In vivo experiments showed that PDT could inhibit tumor growth and upregulate HIF-1α and PD-L1 expressions in NSCLC tissues with a positive correlation, which might influence the blocking activity of ICIs on the HIF-1, and PD-L1-related signaling pathways.ConclusionsPDT might improve the clinical response of ICIs by upregulating tumor HIF-1α and PD-L1 expressions in NSCLC.

CD146 Promotes EMT-Mediated Migration and Invasion of NSCLC via PI3K/Akt Signaling Pathway.

Recurrence and metastasis are the main causes of non-small cell lung cancer (NSCLC)-related death. CD146 has been identified as a potential risk factor for poor prognosis, closely related to the distant metastasis and drug resistance in various cancers. However, the clinical significance of CD146 in NSCLC requires further investigation. This study explored the correlation between CD146 expression and clinical variables using tumor tissue samples collected from our hospital. CD146 expression levels in NSCLC cell lines and tissues were assessed and compared using immunohistochemistry, real-time polymerase chain reaction (RT-qPCR), flow cytometry, and western blot analysis. The invasion and migration capabilities of tumor cells were determined using transwell and wound healing assays. The levels of proteins related to epithelial-mesenchymal transition (EMT) as well as the underlying PI3K/Akt signaling pathway was measured by western blotting. We discovered that CD146 expression is significantly associated with the EMT signaling pathway. High CD146 expression predicted lymph node metastasis, metastasis to distant organs, advanced Tumor, Node, Metastasis (TNM) staging, and poor survival in NSCLC patients. Wound healing and transwell assays showed that knocking down CD146 significantly suppressed cell migration along with cell invasion in NSCLC, whereas overexpressing CD146 notably enhanced these processes. Western blot analysis revealed significantly reduced levels of N-cadherin, vimentin, snail, twist, PI3K, and AKT phosphorylation in shCD146 H460 cells compared to vector control cells. Treatment with PI3K inhibitor PI3K-IN-1 increased E-cadherin expression levels but reduced N-cadherin, Twist, Vimentin, PI3K, and AKT phosphorylation levels in pcDNA3.1-CD146 A549 cells compared with the vector control cells. CD146 expression acts as a prognostic risk factor for adverse outcomes in NSCLC, promoting invasion and metastasis by activating the EMT through the PI3K/Akt signaling pathway. These findings underscore the potential therapeutic strategies targeting CD146, offering new treatment options for NSCLC patients, especially those at risk of metastasis.

A novel cancer-germline gene DAZL promotes progression and cisplatin resistance of non-small cell lung cancer by upregulating JAK2 and MCM8

Germline-specific genes are usually activated in cancer cells and drive cancer progression; such genes are called cancer-germline or cancer-testis genes. The RNA-binding protein DAZL is predominantly expressed in germ cells and plays a role in gametogenesis as a translational activator or repressor. However, its expression and role in non-small cell lung cancer (NSCLC) are unknown. Here, mining of RNA-sequencing data from public resources and immunohistochemical analysis of tissue microarrays showed that DAZL was expressed exclusively in testis among normal human tissues but ectopically expressed in NSCLC tissues. Testis and NSCLC cells expressed the shorter and longer transcript variants of the DAZL gene, respectively. Overexpression of the longer DAZL transcript promoted tumor growth in a mouse xenograft model. Silencing of DAZL suppressed cell proliferation, colony formation, migration, invasion, and cisplatin resistance in vitro and tumor growth in vivo. Quantitative proteomic analysis based on tandem mass tag and Western blot analysis showed that DAZL upregulated the expression of JAK2 and MCM8. RNA-binding protein immunoprecipitation assays showed that DAZL bound to the mRNA of JAK2 and MCM8. The JAK2 inhibitor fedratinib attenuated the oncogenic outcomes induced by DAZL overexpression, whereas silencing MCM8 counteracted the effects of DAZL overexpression on cisplatin-damaged DNA synthesis and half-maximal inhibitory concentration of cisplatin. In conclusion, DAZL was identified as a novel cancer-germline gene that enhances the translation of JAK2 and MCM8 to promote NSCLC progression and resistance to cisplatin, respectively. These findings suggest that DAZL is a potential therapeutic target in NSCLC.

Hedgehog ligand and receptor cooperatively regulate EGFR stability and activity in non-small cell lung cancer.

The hyperactivation of epidermal growth factor receptor (EGFR) plays a crucial role in non-small cell lung cancer (NSCLC). Hedgehog (Hh) signaling has been implicated in the tumorigenesis and progression of various cancers, however, its function in NSCLC cells remains controversial. Herein, we present a novel finding that challenges the current understanding of Hh signaling in tumor growth. Expression of Hh ligands and receptor were assessed using TCGA datasets, immunoblotting and immunohistochemical. Biological function of Hh ligands and receptor in NSCLC were tested using colony formation, cell count kit-8 (CCK-8) and xenograft assays. Biochemical effect of Hh ligands and receptor on regulating EGFR stability and activity were checked via immunoblotting. Expression of Hh ligands and receptor was suppressed in NSCLC tissues, and the lower expression levels of these genes were associated with poor prognosis. Ptch1 binds to EGFR and facilitates its poly-ubiquitylation and degradation independent of downstream transcriptional signaling. Moreover, Hh ligands cooperate with Ptch1 to regulate the protein stability and activity of EGFR. This unique mechanism leads to a suppressive effect on NSCLC tumor growth. Non-canonical Hh signaling pathway, involving cooperation between Hh ligands and their receptor Ptch1, facilitates the degradation of EGFR and attenuates its activity in NSCLC. These findings provide novel insights into the regulation of EGFR protein stability and activity, offer new diagnostic indicators for molecular typing of NSCLC and identify potential targets for targeted therapy of this challenging disease.

Knockdown of NCAPD3 inhibits the tumorigenesis of non-small cell lung cancer by regulation of the PI3K/Akt pathway

BackgroundAccumulating evidence indicates that aberrant non-SMC condensin II complex subunit D3 (NCAPD3) is associated with carcinogenesis of various cancers. Nevertheless, the biological role of NCAPD3 in the pathogenesis of non-small cell lung cancer (NSCLC) remains unclear.MethodsImmunohistochemistry and Western blot were performed to assess NCAPD3 expression in NSCLC tissues and cell lines. The ability of cell proliferation, invasion, and migration was evaluated by CCK-8 assays, EdU assays, Transwell assays, and scratch wound healing assays. Flow cytometry was performed to verify the cell cycle and apoptosis. RNA-sequence and rescue experiment were performed to reveal the underlying mechanisms.ResultsThe results showed that the expression of NCAPD3 was significantly elevated in NSCLC tissues. High NCAPD3 expression in NSCLC patients was substantially associated with a worse prognosis. Functionally, knockdown of NCAPD3 resulted in cell apoptosis and cell cycle arrest in NSCLC cells as well as a significant inhibition of proliferation, invasion, and migration. Furthermore, RNA-sequencing analysis suggested that NCAPD3 contributes to NSCLC carcinogenesis by regulating PI3K/Akt/FOXO4 pathway. Insulin-like growth factors-1 (IGF-1), an activator of PI3K/Akt signaling pathway, could reverse NCAPD3 silence-mediated proliferation inhibition and apoptosis in NSCLC cells.ConclusionNCAPD3 suppresses apoptosis and promotes cell proliferation via the PI3K/Akt/FOXO4 signaling pathway, suggesting a potential use for NCAPD3 inhibitors as NSCLC therapeutics.

LncRNA MRPL39 inhibits cell proliferation and migration by regulating miR-130/TSC1 axis in non-small cell lung cancer.

Currently, the effect of miR-130 on non-small cell lung cancer (NSCLC) remains controversial. In this study, the expression of miR-130 and lncRNA MRPL39 in tumor and non-tumor tissues of NSCLC patients was examined using real-time PCR (RT-PCR) and correlated with the prognosis of NSCLC. The phenotypic effects of miR-130 and MRPL39 on proliferation and migration of NSCLC cell line A549 cells were assessed through CCK-8 and Transwell assays with miR-130 mimic and MRPL39 (mitochondrial ribosomal protein L39) overexpressed plasmid transfection. StarBase/TargetScan analysis and dual-luciferase reporter gene assays were conducted to investigate the relationship between MRPL39, miR-130, and Tuberculosis sclerosis 1 (TSC1). MiR-130 was overexpressed, and MRPL39 was downregulated in NSCLC tissues and cells. Inhibition of miR-130 expression and overexpression of MRPL39 resulted in the inhibition of the viability and migration of A549 cells. MRPL39 is a potential upstream regulatory long non-coding RNA of miR-130, and its expression is negatively regulated by miR-130. TSC1 was identified as a target of miR-130, suppressing the antitumor effects of FGD5-AS1 silencing on GBM cells. After overexpression of MRPL39, the mRNA and protein levels of TSC1 in A549 cells significantly increased. However, after transfection with miR-130 mimic, the up-regulation of mRNA and protein was inhibited, leading to the suppression of cell proliferation and migration.

CircFTO from M2 macrophage-derived small extracellular vesicles (sEV) enhances NSCLC malignancy by regulation miR-148a-3pPDK4 axis

BackgroundAccumulation studies found that tumor-associated macrophages (TAMs) are a predominant cell in tumor microenvironment (TME), which function essentially during tumor progression. By releasing bioactive molecules, including circRNA, small extracellular vesicles (sEV) modulate immune cell functions in the TME, thereby affecting non-small cell lung cancer (NSCLC) progression. Nevertheless, biology functions and molecular mechanisms of M2 macrophage-derived sEV circRNAs in NSCLC are unclear.MethodsCellular experiments were conducted to verify the M2 macrophage-derived sEV (M2-EV) roles in NSCLC. Differential circRNA expression in M0 and M2-EV was validated by RNA sequencing. circFTO expression in NSCLC patients and cells was investigated via real-time PCR and FISH. The biological mechanism of circFTO in NSCLC was validated by experiments. Our team isolated sEV from M2 macrophages (M2Ms) and found that M2-EV treatment promoted NSCLC CP, migration, and glycolysis.ResultsHigh-throughput sequencing found that circFTO was highly enriched in M2-EV. FISH and RT-qPCR confirmed that circFTO expression incremented in NSCLC tissues and cell lines. Clinical studies confirmed that high circFTO expression correlated negatively with NSCLC patient survival. Luciferase reporter analysis confirmed that miR-148a-3p and PDK4 were downstream targets of circFTO. circFTO knockdown inhibited NSCLC cell growth and metastasis in in vivo experiments. Downregulating miR-148a-3p or overexpressing PDK4 restored the malignancy of NSCLC, including proliferation, migration, and aerobic glycolysis after circFTO silencing.ConclusionThe study found that circFTO from M2-EV promoted NSCLC cell progression and glycolysis through miR-148a-3p/PDK4 axis. circFTO is a promising prognostic and diagnostic NSCLC biomarker and has the potential to be a candidate NSCLC therapy target.

Oncogenic circ-SLC16A1 promotes progression of non-small cell lung cancer via regulation of the miR-1287-5p/profilin 2 axis

BackgroundCircular RNAs (circRNAs) are single-stranded RNAs with covalently closed structures that have been implicated in cancer progression. However, the regulatory mechanisms remain largely unclear. So, the aim of this study was to reveal the role and regulatory mechanisms of circ-SLC16A1.MethodsIn this study, next-generation sequencing was used to identify abnormally expressed circRNAs between cancerous and para-carcinoma tissues. Fluorescence in situ hybridization and quantitative reverse transcription polymerase chain reaction were performed to assess the expression patterns of circ-solute carrier family 16 member 1 (SLC16A1) in non-small cell lung cancer (NSCLC) cells and tissue specimens. The dual-luciferase reporter assay was utilized to identify downstream targets of circ-SLC16A1. Transwell migration, wound healing, 5-ethynyl-2′-deoxyuridine incorporation, cell counting, and colony formation assays were conducted to assess the proliferation and migration of NSCLC cells. A mouse tumor xenograft model was employed to determine the roles of circ-SLC16A1 in NSCLC progression and metastasis in vivo.ResultsThe results found that circ-SLC16A1 was upregulated in NSCLC cells and tissues. Downregulation of circ-SLC16A1 inhibited tumor growth by reducing proliferation, lung metastasis, and lymphatic metastasis of NSCLC cells, and arrested the cell cycle in the G1 phase. Also, silencing of circ-SLC16A1 promoted apoptosis of NSCLC cells. The results of bioinformatics analysis and the dual-luciferase reporter assay confirmed that microRNA (miR)-1287-5p and profilin 2 (PFN2) are downstream targets of circ-SLC16A1. PFN2 overexpression or circ-SLC16A1 inhibition restored proliferation and migration of NSCLC cells after silencing of circ-SLC16A1. PFN2 overexpression restored migration and proliferation of NSCLC cells post miR-1287-5p overexpression.ConclusionsCollectively, these findings show that miR-1287-5p/PFN2 signaling was associated with downregulation of circ-SLC16A1 and reduced invasion and proliferation of NSCLC cells. So, circ-SLC16A1 is identified as a mediator of multiple pro-oncogenic signaling pathways in NSCLC and can be targeted to suppress tumor progression.

Exosomal circ_0000735 contributes to non-small lung cancer malignant progression.

Circular RNA is an important regulator for non-small cell lung cancer (NSCLC). Circ_0000735 has been found to be significantly overexpressed in NSCLC tissues. Therefore, its role and mechanism in NSCLC progression need to be further explored. The expression levels of circ_0000735, miR-345-5p and A disintegrin and metalloprotease 19 (ADAM19) were determined using quantitative real-time PCR. EdU staining, wound healing and transwell assays were utilized to detect cell proliferation and metastasis. The protein levels of metastasis markers, exosome markers and ADAM19 were determined using western blot. Animal experiments were performed to confirm the role of circ_0000735 in NSCLC tumorigenesis. The exosomes from cells and serum were identified using transmission electron microscopy and nanoparticle tracking analysis. We found that circ_0000735 was upregulated in NSCLC, and its knockdown repressed NSCLC cell proliferation and metastasis. In terms of mechanism, circ_0000735 targeted miR-345-5p to regulate ADAM19. MiR-345-5p inhibitor reversed the suppressive effect of circ_0000735 knockdown on NSCLC progression, and ADAM19 overexpression abolished the inhibition effect of miR-345-5p on NSCLC progression. Also, animal experiments showed that silencing of circ_0000735 reduced NSCLC tumorigenesis. In addition, exosomes mediated the intercellular transmission of circ_0000735, and serum exosomal circ_0000735 might be an important indicator for the diagnosis of NSCLC. In conclusion, circ_0000735 facilitated NSCLC progression via miR-345-5p/ADAM19 pathway, and serum exosomal circ_0000735 might be a potential biomarker for NSCLC diagnosis.

Molecular subtypes of lung adenocarcinoma present distinct immune tumor microenvironments.

Overcoming resistance to immune checkpoint inhibitors is an important issue in patients with non-small-cell lung cancer (NSCLC). Transcriptome analysis shows that adenocarcinoma can be divided into three molecular subtypes: terminal respiratory unit (TRU), proximal proliferative (PP), and proximal inflammatory (PI), and squamous cell carcinoma (LUSQ) into four. However, the immunological characteristics of these subtypes are not fully understood. In this study, we investigated the immune landscape of NSCLC tissues in molecular subtypes using a multi-omics dataset, including tumor-infiltrating leukocytes (TILs) analyzed using flow cytometry, RNA sequences, whole exome sequences, metabolomic analysis, and clinicopathologic findings. In the PI subtype, the number of TILs increased and the immune response in the tumor microenvironment (TME) was activated, as indicated by high levels of tertiary lymphoid structures, and high cytotoxic marker levels. Patient prognosis was worse in the PP subtype than in other adenocarcinoma subtypes. Glucose transporter 1 (GLUT1) expression levels were upregulated and lactate accumulated in the TME of the PP subtype. This could lead to the formation of an immunosuppressive TME, including the inactivation of antigen-presenting cells. The TRU subtype had low biological malignancy and "cold" tumor-immune phenotypes. Squamous cell carcinoma (LUSQ) did not show distinct immunological characteristics in its respective subtypes. Elucidation of the immune characteristics of molecular subtypes could lead to the development of personalized immune therapy for lung cancer. Immune checkpoint inhibitors could be an effective treatment for the PI subtype. Glycolysis is a potential target for converting an immunosuppressive TME into an antitumorigenic TME in the PP subtype.

“Crosstalk between non-coding RNAs and transcription factor LRF in non-small cell lung cancer”

Epigenetic approaches in direct correlation with assessment of critical genetic mutations in non-small cell lung cancer (NSCLC) are currently very intensive, as the epigenetic components underlying NSCLC development and progression have attained high recognition. In this level of research, established human NSCLC cell lines as well as experimental animals are widely used to detect novel biomarkers and pharmacological targets to treat NSCLC. The epigenetic background holds a great potential for the identification of epi-biomarkers for treatment response however, it is highly complex and requires precise definition as these phenomena are variable between NSCLC subtypes and systems origin.We engaged an in-depth characterization of non-coding (nc)RNAs prevalent in human KRAS-mutant NSCLC cell lines A549 and H460 and mouse KRAS-mutant NSCLC tissue by Next Generation Sequencing (NGS) and quantitative Real Time PCRs (qPCRs). Also, the transcription factor (TF) LRF, a known epigenetic silencer, was examined as a modulator of non-coding RNAs expression. Finally, interacting networks underlying epigenetic variations in NSCLC subtypes were created. Data derived from our study highlights the divergent epigenetic profiles of NSCLC of human and mouse origin, as well as the significant contribution of 12qf1: 109,709,060–109,747,960 mouse chromosomal region to micro-RNA upregulated species. Furthermore, the novel epigenetic miR-148b-3p/lncPVT1/ZBTB7A axis was identified, which differentiates human cell line of lung adenocarcinoma from large cell lung carcinoma, two characteristic NSCLC subtypes.The detailed recording of epigenetic events in NSCLC and combinational studies including networking between ncRNAs and TFs validate the identification of significant epigenetic features, prevailing in NSCLC subtypes and among experimental models. Our results enrich knowledge in the field and empower research on the epigenetic prognostic biomarkers of the disease progression, NSCLC subtypes discrimination and advancement to patient-tailored treatments.

MicroRNA‑373‑3p inhibits the proliferation and invasion of non‑small‑cell lung cancer cells by targeting the GAB2/PI3K/AKT pathway.

MicroRNAs (miRNAs) were previously demonstrated to be involved in the pathogenesis of non-small-cell lung cancer (NSCLC); however, the roles of certain miRNAs in NSCLC remain to be elucidated. The present study aimed to investigate the functions of screened miRNAs in NSCLC and the potential mechanisms. First, expression profiles of miRNAs were downloaded from the Gene Expression Omnibus (dataset no. GSE29248) and the differentially expressed miRNAs were analyzed by bioinformatics methods. Reverse transcription-quantitative PCR was used to validate the differential expression of miR-373 in clinical samples. The association between miR-373 expression levels and clinicopathological characteristics was also investigated. To further examine how miR-373 mediates the emergence of NSCLC, western blot, Cell Counting Kit-8, cell invasion and wound-healing assays, as well as apoptosis detection and a luciferase assay were used. The results indicated significant downregulation of miR-373 in NSCLC tissues and its low expression was closely associated with the degree of differentiation, clinical stage and tumor size, and was indicative of an unfavorable prognosis for patients with NSCLC. A functional study indicated that overexpression of miR-373 inhibited the proliferation, promoted apoptosis, and suppressed invasion and migration of NSCLC cells. Bioinformatics prediction and functional assays suggested that Grb-associated binding protein 2 (GAB2) was a direct target of miR-373. In addition, GAB2 was found to be significantly upregulated in NSCLC tissues, and clinically, miR-373 was negatively associated with GAB2. Furthermore, overexpression of GAB2 blocked the tumor suppressive effects of miR-373 on NSCLC cells. Mechanistically, miR-373 mimics were able to reduce the expression of GAB2 and subsequently decrease the phosphorylation level of AKT and mTOR protein. The present results indicate that miR-373 exerts its anti-tumor effects in NSCLC cells by targeting the GAB2/PI3K/AKT pathway, suggesting that miR-373 may be a potential therapeutic target in NSCLC.

Abstract 1538: Impact of C-reactive protein on the efficacy of immune checkpoint inhibitors in non-small cell lung cancer

Abstract Background: Immune checkpoint inhibitors (ICIs) therapy has achieved remarkable success in the treatment of non-small cell lung cancer (NSCLC). Clinical studies have suggested a correlation between C-reactive protein (CRP) levels and treatment efficacy, but it remains unclear whether CRP can directly impact the efficacy. Therefore, we investigated the imapct of CRP on the efficacy of ICIs in NSCLC. Methods: The tumor growth model was established in CRP knockout and wildtype mice by injecting LLC cells to evaluate the effect of CRP on tumor proliferation. The frequencies and phenotypes of macrophages and T cells in mouse tumors were detected by flow cytometry. The impact of CRP on macrophage polarization was evaluated using flow cytometry and IF, while its impact on T cell chemokines CCL5, CXCL9, and CXCL10 was analyzed by ELISA and qRT-PCR. mCRP and α-PD-1 were implemented in C57/BL6 mice injected with LLC cells to evaluate the effect of mCRP on tumor immunotherapy. The frequencies of T cells in mouse tumors were detected by flow cytometry. Expression of mCRP and infiltration of immune cells in human NSCLC tissues were analyzed using IHC. Results: We found that tumor progression was enhanced and the proportion of tumor-infiltrated M1 macrophages was decreased in CRP knockout mice. Using human PBMC-derived macrophage and RAW264.7 cell lines, we demonstrated that the monomeric form of CRP, known as mCRP, induced M1 polarization of macrophages, leading to increased secretion of CCL5, CXCL9, and CXCL10. In tumor bearing mice, mCRP treatment enhanced anti-tumor immunity and suppressed tumor progression by increasing CD4+ and CD8+ T cell recruitment. Surprisingly, the combined treatment of mCRP and α-PD-1 induced more significant tumor regression than α-PD-1 treatment alone. Additionally, high level of mCRP in NSCLC tissues is correlated with a more inflamed tumor microenvironment phenotype. Conclusion: mCRP can enhance the efficacy of immune checkpoint inhibitors in NSCLC by activating anti-tumor immunity. Citation Format: Wenyuan Li, Hui Guo. Impact of C-reactive protein on the efficacy of immune checkpoint inhibitors in non-small cell lung cancer [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 1538.

Abstract 641: SCD1 upregulation due to STK11/KEAP1 loss upregulates SLC7A11 and causes deregulation of fatty acid metabolism leading to ferroptosis evasion

Abstract Introduction: Non-small cell lung cancer (NSCLC) with co-occurring loss-of-function (LOF) mutations in serine/threonine kinase 11 (STK11) and Kelch-like ECH-associated protein1 (KEAP1) (SK) are notably aggressive and unresponsive to chemo and immunotherapy, in current care standards. Novel therapeutic strategies are in demand to improve the outcomes for SK co-mutant NSCLC patients. We reported earlier that SK LOF mutations enhance cell proliferation and tumor growth in xenograft lung cancer models. We also found the ferroptosis evasion genes are enriched, and targeting ferroptosis regulators is a therapeutic opportunity in SK co-mutant NSCLC. Methods: We used CRISPR/Cas9 gene editing to create stable knockouts of STK11 (SKO), KEAP1 (KKO) or both (DKO), non-targeting control (NTC) in two NSCLC lines. We performed an in vitro druggable genome library CRISPR screening in the same NSCLC lines. We performed kinase profiling and RNA-seq in the cell lines to depict the transcriptomic and proteomic landscape, followed by western blotting and qRT-PCR validation. We also performed BODIPY/C11 assay and lipidomics to explore the ferroptosis and metabolic landscape of SK co-mutant NSCLC models. Results: Stearoyl CoA desaturase-1 (SCD1) was the top CRISPR screen hit, a critical modulator of fatty acid metabolism and ferroptosis evasion. SCD1 expression is significantly higher in NSCLC tissue than adjacent normal tissue (p&amp;lt;0.0001), and high SCD1 expression correlates with poorer prognosis in patients with NSCLC (p=0.027). GSEA from the bulk RNA sequencing in SK co-mutant cells pre-and post-SCD1 inhibitor treatment showed SCD1 inhibition leads to upregulation of the glutathione and glutamic acid pathways compared to NTC cells. Moreover, SK co-mutant cells have a significantly higher expression of SLC7A11, enabling cystine uptake and subsequent conversion to cysteine, essential for maintaining redox balance and cell survival. Hence, SK co-mutant cells are more resistant to cysteine depletion than NTC cells. SCD1 inhibition causes a decrease in SLC7A11 expression exclusively in DKO cells. Eventually, SCD1 inhibition leads to global metabolomic changes in SK co-mutant cells, including key pathways involved in lipid and glucose metabolism. Finally, genetic and pharmacological inhibition of SCD1 prevents tumor growth and sensitizes DKO cells to ferroptosis inducers like erastin. Conclusions: Our findings highlight the importance of the SCD1-SLC7A11 axis in regulating ferroptosis in SK co-mutant models. Current data impact our understanding of ferroptosis in NSCLC and its ability to target SCD1 or ferroptosis in cancer treatment. Compounds such as inhibitors of SLC7A11 (Erastin/IKE) are safe to use with acceptable toxicity and established doses. Hence, our study will facilitate the translation of ferroptosis inducers or SCD1 inhibitors in clinical trials. Citation Format: Utsav Sen, Charles Coleman, Dan Hasson, Triparna Sen. SCD1 upregulation due to STK11/KEAP1 loss upregulates SLC7A11 and causes deregulation of fatty acid metabolism leading to ferroptosis evasion [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 641.

Abstract 6568: PTCH1 loss-of-function alterations: Mutational landscape and therapeutic outcomes to hedgehog pathway inhibitors in non-canonical histologies

Abstract Background: Loss-of-function (LOF) alterations of the PTCH1 tumor suppressor gene represent canonical events involved in basal cell carcinoma (BCC) oncogenesis. Hedgehog pathway inhibitors (HPIs) are approved for the treatment of advanced BCC, but genomic characterization and therapeutic outcomes remain limited in tumor agnostic cohorts. Methods: Using the MSK Clinical Sequencing Cohort, we performed a mutational landscape analysis of PTCH1 LOF alterations in non-BCC histologies, including Fraction and Allele-Specific Copy Number Estimates from Tumor Sequencing (FACETS) annotation, and analyzed response and progression-free survival (PFS) with HPIs. Results: Out of 115,619 samples, 1972 samples from advanced solid tumors with PTCH1 LOF alterations were identified. Excluding 1306 variants of unknown significance (VUSs) using OncoKB knowledge base as well as 44 BCC samples, a total of 622 samples from 570 patients with oncogenic PTCH1 alterations were identified across histologies. In addition, 124 patients received ≥1 line(s) of HPI at our institution between 2013 and 2023, including 16 patients with non-BCC histologies presenting PTCH1 alterations. At the patient level (n=570), PTCH1 LOF alterations were present across 33 primary sites, including colorectal cancer (CRC; 34%; n=192), endometrial cancer (17%; n=98), gastroesophageal adenocarcinomas (ADC) (8%; n=46), non-small cell lung cancer (NSCLC; 6%; n=34) and soft tissue sarcomas (STS; 4%; n=25). At the sample level (n=622), TMB ≥10 was seen in 83% (n=516), including 324 samples with MSI-high status. PTCH1 alterations most frequently involved frameshift (fs) indels (69%; n=429), followed by nonsense mutations (18%; n=114), splice site mutations (8%; n=47) and fusions (5%; n=32). Recurrent fs events involved S1203Afs*52 (24%; n=150) and R1308Efs*64 (14%; n=89), among others. When comparing monoallelic (monoall) vs biallelic (biall) PTCH1 alterations through FACETS annotation, monoall showed a strong association with higher TMB (p&amp;lt;0.01) whereas biall were associated with higher loss of heterozygosity (LOH; p&amp;lt;0.01). In the 16 non-BCC patients treated with HPIs, histologies included lung squamous cell cancer (SCC; n=4), cutaneous SCC (n=2), medulloblastoma (n=2), carcinosarcoma (n=2), osteosarcoma, chondrosarcoma, chordoma, sebaceous ADC, anal SCC and CRC (each n=1). TMB ≥10 was seen in 31% (n=5), all of which were MSI-low. Tumor regressions on HPI were seen in 50% (n=8), including lung SCC, cutaneous SCC, sebaceous ADC and medulloblastoma, with median time to response of 3.6 months (mo). Median PFS on HPI was 3.9 mo and median OS was 22.7 mo. Median PFS was higher in patients with TMB ≥10 vs TMB &amp;lt;10 (11.8 vs. 1.8 mo, p=0.02). Conclusion: PTCH1 LOF alterations appear actionable in non-BCC cutaneous/adnexal primaries, lung SCC and medulloblastoma, including TMB-high tumors. Citation Format: Antoine Desilets, Matteo Repetto, Soo Ryum Yang, Monica Chen, Dazhi Liu, Nikhil Rizvi, Ezra Rosen, Alan L. Ho, Alexander Drilon, Yonina R. Murciano-Goroff. PTCH1 loss-of-function alterations: Mutational landscape and therapeutic outcomes to hedgehog pathway inhibitors in non-canonical histologies [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 6568.