Lung Adenocarcinoma Tumor Research Articles

EXO1 is a key gene for lung-resident memory T cells and has diagnostic and predictive values for lung adenocarcinoma

Lung adenocarcinoma (LUAD) is a very common and lethal kind of lung malignancy. An increasing number of studies indicated that tissue-resident memory T (TRM) cells played significant roles in anti-cancer immunity. In our previous study, EXO1 was found to be a core gene for TRM cells in the prognosis of LUAD. However, the roles of EXO1 in the tumor microenvironment, and its application in the diagnosis and prognosis prediction of LUAD are still inadequately explored. In this study, the RNA expression, DNA methylation, CNV, somatic mutation data of EXO1, and the corresponding patients’ clinical information from publicly available databases were analyzed using bioinformatic methods. The results were validated through immunohistochemical staining of EXO1 in LUAD samples. The results showed EXO1 was aberrantly highly expressed in LUAD tissues. High expression of EXO1 was a risky factor for LUAD patients. The expression level of EXO1 was associated with many clinical features such as TNM stages. It can also distinguish normal tissues and LUAD tumor tissues accurately. EXO1 expression was correlated with the infiltration of immune cells, and high expression of EXO1 was an adverse effect on LUAD patients receiving anti-PD-1/PD-L1 immunotherapy. Moreover, patients with EXO1 mutation had worse DSS, DFI and PFI.

Comparison of imaging-based single-cell resolution spatial transcriptomics profiling platforms using formalin-fixed, paraffin-embedded tumor samples.

Imaging-based spatial transcriptomics (ST) is evolving rapidly as a pivotal technology in studying the biology of tumors and their associated microenvironments. However, the strengths of the commercially available ST platforms in studying spatial biology have not been systematically evaluated using rigorously controlled experiments. In this study, we used serial 5-µm sections of formalin-fixed, paraffin-embedded surgically resected lung adenocarcinoma and pleural mesothelioma tumor samples in tissue microarrays to compare the performance of the single cell ST platforms CosMx, MERFISH, and Xenium (uni/multi-modal) platforms in reference to bulk RNA sequencing, multiplex immunofluorescence, GeoMx Digital Spatial Profiler, and hematoxylin and eosin staining data for the same samples. In addition to objective assessment of automatic cell segmentation and phenotyping, we performed pixel-resolution manual evaluation of phenotyping to carry out pathologically meaningful comparison between ST platforms. Our study detailed the intricate differences between the ST platforms, revealed the importance of parameters such as tissue age and probe design in determining the data quality, and suggested reliable workflows for accurate spatial profiling and molecular discovery.

Preoperative CT-based radiomics nomogram to predict the micropapillary pattern in lung adenocarcinoma of size 2 cm or less.

To develop and validate a radiomics nomogram model for predicting the micropapillary pattern (MPP) in lung adenocarcinoma (LUAD) tumors of ≤2 cm in size. In this study, 300 LUAD patients from our institution were randomly divided into the training cohort (n = 210) and an internal validation cohort (n = 90) at a ratio of 7:3, besides, we selected 65 patients from another hospital as the external validation cohort. The region of interest of the tumor was delineated on the computed tomography (CT) images, and radiomics features were extracted. A nomogram model was established using radiomics features, clinical features and conventional radiographic features. The nomogram model was compared with the radiomics model and the clinical model alone to test its diagnostic validity. Receiver operating characteristic (ROC) curves, areas under the ROC curves and decision curve analysis (DCA) results were plotted to evaluate the model performance and clinical application. The nomogram model exhibited superior performance, with an AUC of 0.905 (95% confidence interval [CI]: 0.857-0.951) in the training cohort, which decreased to 0.817 (95% CI: 0.698-0.936) in the external validation cohort. The clinical model had AUCs of 0.820 (95% CI: 0.753-0.886) and 0.730 (95% CI: 0.572-0.888) in the training and external validation cohorts, respectively. The radiomics model had AUCs of 0.895 (95% CI: 0.840-0.949) and 0.800 (95% CI: 0.675-0.924) for training and external validation, respectively. DCA confirmed that the nomogram model had the better clinical benefit. The nomogram model achieved promising prediction efficiency for identifying the presence of the MPP in LUAD tumors ≤2 cm, allowing clinicians to develop more rational and efficacious personalized treatment strategies.

Risk factors for brain metastasis in lung cancer: an umbrella review of systematic reviews and meta-analyses

ObjectivesTo conduct an umbrella review to extensively evaluate and summarise the evidence regarding the relationship between risk factors and the occurrence of brain metastasis in lung cancer.DesignUmbrella review of systematic...

Clinical Versus Pathological Staging in Patients with Resected Ground Glass Pulmonary Lesions.

A ground glass nodule (GGN) is a radiologically descriptive term for a lung parenchymal area with increased attenuation and preserved bronchial and vascular structures. GGNs are further divided into pure versus subsolid lesions. The differential diagnosis for GGNs is wide and contains a malignant possibility for a lung adenocarcinoma precursor or tumor. Clinical and pathological staging of GGNs is based on the lesions' solid component and falls into a specific classification including T0 for TIS, T1mi for minimally invasive adenocarcinoma (MIA) and T1abc for lepidic predominant adenocarcinoma (LPA) according to the eighth edition of the TNM classification of lung cancer. Correlation between solid parts seen on a CT scan and the tumor pathological invasive component is not absolute. This retrospective study collected the data of 68 GGNs that were operated upon in Carmel Medical Center. A comparison between preoperative clinical staging and post-surgery pathological staging was conducted. Over a third of the lesions, twenty-four (35.3%), were upstaged while only four (5.9%) lesions were downstaged. Another third of the lesions, twenty-three (33.8%), kept their stage. In three (4.4%) cases, premalignant lesion atypical adenomatous hyperplasia (AAH) was diagnosed. Ten (14.7%) cases were diagnosed as non-malignant on final pathology. These findings show an overall low agreement between the clinical and pathological stages of GGNs. The relatively high percentage of upstaging tumors detected in this study and the overall safe and short surgical procedure advocate for surgical resection even in the presence of a significant number of non-malignant lesions that retrospectively do not mandate intervention at all.

High expression of SLC2A1 inhibits ferroptosis and promotes proliferation and invasion of lung adenocarcinoma cells

To examine how the glucose transporter SLC2A1 influences the proliferation and migration of lung adenocarcinoma (LUAD) and explore the underlying molecular mechanisms. We examined the differential expression of SLC2A1 between normal and LUAD tissues in the TCGA database and its prognostic implications. Immunohistochemistry was used to detect SLC2A1 protein levels in clinical samples of LUAD and adjacent tissues, and the association of SLC2A1 expression levels with clinicopathological features of the patients was analyzed. In PC9 cells with stable SLC2A1 overexpression or knockdown, the effects of SLC2A1 expression level on cell proliferation and migration were assessed using CCK-8 and Transwell assays, and the changes in expressions of ferroptosis- and autophagy-related proteins were measured; the occurrence of ferroptosis was confirmed using ROS and Fe2+ fluorescence staining. SLC2A1 expression was significantly higher in LUAD tumor tissues than in normal lung tissues (P<0.05) and was associated with worse pathological parameters and prognosis of the patients (P<0.05). In PC9 cells, SLC2A1 overexpression significantly promoted cell proliferation, invasion and migration, and SLC2A1 knockdown significanty increased cell death and inhibited cell invasion and proliferation. SLC2A1 knockdown caused obvious activation of cell ferroptosis, reduced GPX4 and xCT expressions, and increased intracellular levels of ROS and Fe2+. SLC2A1 knockdown also resulted in increased cell autophagy shown by increased LC3B expression, which could be reversed by treatement with 3-MA. High SLC2A1 expression is correlated with poor prognosis of patients with LUAD, and inhibiting SLC2A1 can induce ferroptosis and autophagy of LUAD cells, suggesting the potential of SLC2A1 as a target for LUAD diagnosis and treatment.

TFAP2A Promotes Cell Progression and Suppresses Ferroptosis in Lung Adenocarcinoma via Activating Transcription of CST1.

Lung adenocarcinoma (LUAD) is a common type of lung cancer with complicated pathological mechanism. Transcription Factor AP-2 Alpha (TFAP2A) and Cysteine protease inhibitor 1 (CST1) are upregulated genes in LUAD samples, accordingly, we focused on clarifying the role of TFAP2A/CST1 axis in LUAD. Expression analysis was performed using real-time quantitative polymerase chain reaction and western blot. Cellular behaviors were detected by colony formation assay, EdU assay, wound healing assay and flow cytometry. Ferroptosis was assessed by oxidative indicators, Fe2+ level and related proteins. TFAP2A and CST1 interaction was analyzed via ChIP assay and dual-luciferase reporter assay. TFAP2A function in vivo was evaluated by xenograft tumor assay. CST1 was overexpressed in LUAD samples and cells. Downregulation of CST1 inhibited proliferation, migration but it promoted apoptosis and ferroptosis of LUAD cells. TFAP2A interacted with the promoter of CST1 to up-regulate CST1 expression. TFAP2A regulated the malignant behaviors and ferroptosis of LUAD cells by targeting CST1. TFAP2A affected LUAD tumor growth via mediating CST1. All these data proved that TFAP2A/CST1 axis contributed to proliferation, migration while it suppressed apoptosis and ferroptosis in LUAD.

IGF2BP2 promotes lung adenocarcinoma progression by regulating LOX1 and tumor-associated neutrophils.

Lung adenocarcinoma (LUAD) is the common form of lung cancer and is prone to distant metastasis. IGF2BP2, an m6A modification regulator, is upregulated in lung cancer tissue, but its specific role within the LUAD tumor microenvironment (TME) is unknown. We explored the role of IGF2BP2 in the progression of LUAD. IGF2BP2 expression in LUAD patient specimens and controls was evaluated through bioinformatics, Western blot, and immunohistochemistry. LUAD subcutaneous and orthotopic xenograft tumor models were established, alongside a co-culture system of tumor-associated neutrophils (TANs) and A549 cells. Functional assays assessed IGF2BP2's role under treatment with JX5, an IGF2BP2 inhibitor. Mechanistic assays explored the interaction between IGF2BP2 and LOX1 in 293T cells. IGF2BP2 was significantly upregulated in LUAD tissues, with higher expression levels predicting worse prognosis for patients (p < 0.001). In subcutaneous and orthotopic xenograft models, treatment with JX5, an IGF2BP2 inhibitor, reduced tumor size, volume, and weight (p < 0.001). JX5 also significantly reduced the concentrations of pro-inflammatory cytokines in peripheral blood (p < 0.01 and p < 0.001). Flow cytometry analysis indicated JX5 reduced CD11b+Ly6G+/CD45+ cells (TANs) in the TME (p < 0.001). Mechanistically, JX5 downregulated LOX1 expression in vivo, and co-culture experiments further demonstrated that IGF2BP2 promotes LUAD progression through LOX1-mediated regulation of TAN activity (p < 0.01 and p < 0.001). Overexpression of LOX1 reversed the inhibitory effects of JX5 on TAN infiltration, tumor cell viability, and apoptosis (p < 0.01 and p < 0.001). Additionally, RNA immunoprecipitation revealed that IGF2BP2 binds to LOX1 mRNA at its m6A modification site, stabilizing LOX1 and enhancing its function in the TME. Knockdown of IGF2BP2 accelerated LOX1 mRNA degradation, confirming its role in maintaining LOX1 stability (p < 0.01 and p < 0.001). IGF2BP2 recognizes and stabilizes LOX1 through m6A modification, contributing to TAN-mediated LUAD progression. Overall, these findings offer new insights into LUAD progression and demonstrate that IGF2BP2 is a key regulator that promotes tumor advancement, highlighting the IGF2BP2-LOX1 axis as a potential therapeutic target for LUAD.

Construction of a neutrophil extracellular trap formation-related gene model for predicting the survival of lung adenocarcinoma patients and their response to immunotherapy.

Lung adenocarcinoma (LUAD) is associated with high morbidity and mortality rates. Increasing evidence indicates that neutrophil extracellular traps (NETs) play a critical role in tumor progression, metastasis and immunosuppression in the LUAD tumor microenvironment (TME). Nevertheless, the use of NET formation-related genes (NFRGs) to predict LUAD patient survival and response to immunotherapy has not been explored. Therefore, this study aimed to construct a NFRGs-based prognostic signature for stratifying LUAD patients and informing individualized management strategies. The cell composition of the LUAD TME was investigated using the single-cell sequencing data in Single-Cell Lung Cancer Atlas (LuCA). NFRGs were identified to construct a prognostic signature based on The Cancer Genome Atlas (TCGA) cohort which was validated in the Gene Expression Omnibus (GEO) dataset. The univariate Cox and least absolute shrinkage and selection operator (LASSO) Cox regression models, receiver operating characteristic (ROC) and Brier Score were applied to assess the prognostic model. A nomogram was established to facilitate the clinical application of the risk score. The Estimation of STromal and Immune cells in MAlignant Tumor tissues (ESTIMATE) and Tumor Immune Dysfunction and Exclusion (TIDE) algorithm were utilized to assess the TME and predict immunotherapy response. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was applied to quantify the expression levels of four NFRGs in LUAD paired tissue samples. Single‑cell RNA sequence analysis showed the importance of neutrophils in LUAD TME. We developed and validated a 4-NFRG (CAT, CTSG, ENO1, TLR2) prognostic signature based on TCGA and GEO cohorts, which stratified patients into high-risk and low-risk groups. Univariate and multivariate analyses showed that our risk model could independently predict the survival of LUAD patients. Patients in the low-risk group exhibited a more active immune microenvironment, lower TIDE scores, lower half-maximal inhibitory concentration (IC50) values and higher immune checkpoint molecule expression. Our risk signature could serve as a biomarker for predicting immunotherapeutic benefits. We developed a novel prognostic signature for LUAD patients based on NFRGs and emphasized the critical role of this signature in predicting LUAD patient survival and immunotherapy response.

SSBP1 positively regulates RRM2, affecting epithelial mesenchymal transition and cell cycle arrest in human lung adenocarcinoma cells

Progression of lung adenocarcinoma (LUAD) is frequently associated with alterations in epithelial-mesenchymal transition (EMT) and cell cycle. Our study analyzed the Cancer Genome Atlas (TCGA) database and identified a positive correlation between high expression of SSBP1 in LUAD tumor tissues and poor prognosis (p < 0.05), with an AUC of 0.853, suggesting that SSBP1 could serve as a prognostic biomarker. In vitro experiments, including siRNA-mediated SSBP1 knockdown and subsequent cell cloning and Transwell assays, revealed significant inhibition of proliferation, migration, and cell cycle progression in LUAD cells (p < 0.05). In vivo mouse model experiments further confirmed that SSBP1 knockdown inhibits tumor burden (p < 0.05). Mechanistic investigations, integrating pathway enrichment analysis with molecular biology techniques, identified RRM2 as a downstream target of SSBP1, and RRM2 knockdown similarly suppressed LUAD cell proliferation, migration, and cell cycle progression (p < 0.05). These findings indicate that SSBP1 promotes EMT and cell cycle progression in LUAD cells by positively regulating RRM2, thereby accelerating disease progression. Collectively, our study not only confirms the potential role of SSBP1 in LUAD but also provides a theoretical foundation for therapeutic strategies targeting the SSBP1/RRM2 axis, potentially offering new therapeutic targets for LUAD patients.

Nucleolar casein kinase 2 alpha as a prognostic factor in patients with surgically resected early‑stage lung adenocarcinoma.

Lung cancer remains a leading cause of global cancer‑related deaths, therefore the identification of prognostic factors for lung cancer is critical. Casein kinase 2 alpha (CK2α) is one of the driver kinases in various cancers, and it was previously demonstrated that CK2α localization was associated with a poor prognosis in invasive breast cancer. In the present study, the importance of CK2α in the nucleolus was explored as a potential prognostic marker for surgically resected early‑stage lung adenocarcinoma. The present study included 118 patients who underwent pulmonary lobectomy between 2014 and 2018 in Fukushima Medical University Hospital (Fukushima, Japan), and in whom CK2α localization in tumor samples was assessed by immunohistochemistry. Patient and tumor characteristics, including pathological stage, histological type and histological grade, were analyzed. Recurrence‑free survival (RFS) and overall survival were evaluated in relation to nucleolar CK2α staining. CK2α staining in the nucleoli was observed in 50.8% of lung adenocarcinoma tumors. Positive nucleolar CK2α staining was independent of pathological stage, histological type and histological grade. Patients with positive nucleolar CK2α staining exhibited significantly worse RFS compared with patients with negative staining. Multivariate analysis identified nucleolar CK2α staining and lymph node metastasis as independent poor prognostic factors. The results of the present study suggested that nucleolar CK2α staining is a novel and independent prognostic factor in surgically resected early‑stage lung adenocarcinoma. These findings indicated the potential of nucleolar CK2α as a predictive biomarker for future recurrence, and a guide to treatment decisions. Further research is required, particularly in understanding the molecular mechanisms linking nucleolar CK2α to recurrence.

Oxidative phosphorylation related gene COA6 is a novel indicator for the prognosis and immune response in lung adenocarcinoma

Although the initial research focused on glycolysis, mitochondrial oxidative phosphorylation has become a major target of cancer cells. Cytochrome C oxidase assembly factor 6 (COA6) is a conserved assembly factor necessary for complex IV biogenesis. Nevertheless, the clinical predictive value of COA6, especially its correlation with immune cell infiltration in lung adenocarcinoma (LUAD), has not yet been elucidated. COA6 exhibited higher expression levels in LUAD cells and tumor tissues compared to normal tissues. Additionally, heightened COA6 expression was associated with reduced overall survival (OS) and advanced tumor stage. Apart from its role in mitochondrial respiratory processes, COA6 may be involved in the process of antigen binding, immunoglobulin receptor binding. Interestingly, we observed a positive correlation between COA6 expression and tumor mutational burden (TMB), as well as a significant association with decreased immune cell infiltration. COA6 was linked to resistance against gemcitabine and etoposide. We verified that COA6 was highly expressed in LUAD experimentally and cell proliferation was inhibited after COA6 knockdown. Thus, we conclude that the expression of COA6 was correlated with reduced immune cell infiltration. Additionally, COA6 functioned as a biomarker for drug sensitivity and the prognosis of lung adenocarcinoma.

BATF-Activated AIM2 Mediates Immune Escape in Lung Adenocarcinoma by Regulating PD-L1

Introduction: Immunotherapy has demonstrated encouraging outcomes in tackling lung adenocarcinoma (LUAD), but immune escape may bring negative impacts. Only a single study has demonstrated the function of AIM2 in LUAD and reported that NF-κB and STAT1 are the chief transcription factors, this study is designed to analyze the role of AIM2 and examine the transcription factor, BATF in LUAD immunotherapy. Methods: Bioinformatics methods to analyze the expression and binding sites of AIM2 and BATF in LUAD, as well as the correlation between AIM2 and PD-L1. Dual-luciferase and chromatin immunoprecipitation assays were used to verify the binding of AIM2 and BATF. qRT-PCR and Western blot assayed expression of AIM2, BATF, and PD-L1 in LUAD. MTT measured cell viability, flow cytometry detected cell apoptosis, cytotoxicity assays measured the toxicity of CD8+ T cells to cancer cells, and enzyme-linked immunosorbent assay measured the expression of related cytokines. Immunohistochemistry detected the protein expression levels of AIM2, BATF, PD-L1, and CD8 in tumor tissue. Results: AIM2 and BATF were both highly expressed in LUAD, and there was a targeted binding relationship. BATF promoted LUAD cell proliferation and inhibited apoptosis by affecting AIM2 expression. The downregulation of AIM2 and PD-L1 expression inhibited PD-L1 and activated CD8+ T cells. The rescue experiment manifested that increased BATF weakened repression of AIM2 silencing on LUAD tumor immune escape in vitro and in vivo. Conclusion: BATF promoted AIM2 expression, upregulated PD-L1, inhibited CD8+ T cell activity, and ultimately led to immune escape in LUAD. Our research uncovered an innovative outlook on the intricate regulation of immune checkpoint molecules and proposed a new approach to target the BATF/AIM2 axis in tumor immunotherapy.

Hsa_circ_0001492 regulates the hsa-miR-145-5p/ovarian carcinoma immunoreactive antigen domain 2 axis to promote the progression of lung adenocarcinoma.

Circular RNA (circRNA) has been proven to be a key regulator in a range of tumor illnesses, such as lung adenocarcinoma (LUAD); however, the regulatory mechanisms of circRNA remain unclear. In this study, circRNA (hsa_circ_0001492) in LUAD was examined for its regulatory and functional potential. qRT-PCR was used to assess the hsa_circ_0001492 level in LUAD. The RNAse R digestion test was employed to isolate hsa_circ_0001492. The primary location of hsa_circ_0001492 enrichment in LUAD cells was identified through a nucleoplasmic separation test. LUAD cell migration, proliferation, and spherogenicity were examined using wound healing, transwell, EdU, and cell spherogenicity assays. The association between miR-145-5p and hsa_circ_0001492/ovarian carcinoma immunoreactive antigen domain 2 (OCIAD2) was validated using a dual luciferase experiment. The interaction between sh-hsa_circ_0001492 and miR-145-5p was confirmed through an RNA pull-down assay. The effects of hsa_circ_0001492, miR-145-5p, and OCIAD2 on LUAD tumor development were examined using xenograft mouse models and immunohistochemistry tests. Results showed a higher amount of hsa_circ_0001492 in LUAD. The cytoplasm of LUAD cells was observed in the area where hsa_circ_0001492 mainly accumulated; hsa_circ_0001492 enhanced LUAD cell migration, proliferation, and sphere-forming ability. MiR-145-5p and OCIAD2 were identified as targets of hsa_circ_0001492 and miR-145-5p, respectively. The level of OCIAD2 was increased by hsa_circ_0001492 through targeted binding to miR-145-5p. In nude mice, tumor growth was inhibited by silencing hsa_circ_0001492, while knockdown of miR-145-5p and overexpression of OCIAD2 promoted the growth of LUAD tumors. In conclusion, hsa_circ_0001492 regulates the hsa-miR-145-5p/OCIAD2 axis to promote the progression of LUAD, and could be a useful target for the diagnosis and treatment of LUAD.

UBE2C promotes LUAD progression by ubiquitin-dependent degradation of p53 to inactivate the p53/p21 signaling pathway

Lung adenocarcinoma (LUAD) is one of the greatest causes of cancer death worldwide. As a novel potential tumor biomarker, ubiquitin-conjugating enzyme E2C (UBE2C) is a critical factor during the onset and development of human cancers. However, the mechanisms of UBE2C in LUAD are not well understood. In this study, increased expression level of UBE2C was observed in LUAD tumor tissues. High LUAD level portended a worse prognosis of LUAD patients. Down-regulation of UBE2C attenuated the cell proliferation and cycle, migration, and invasion. Consistently, the tumorigenic capacity of LUAD cells in nude mice was significantly suppressed by the knockdown of UBE2C. Knockdown of UBE2C inhibited the degradation of p53 protein via an ubiquitin-proteasome pathway, thereby increasing p53 and p21 protein expression. Moreover, the inhibition of LUAD cell malignant phenotypes caused by UBE2C knockdown was attenuated on account of the inactivation of p53/p21 signaling pathway. In conclusion, UBE2C facilitates cell malignant behaviour in LUAD by ubiquitin-dependent degradation of p53 to suppress the p53/p21 signaling pathway. UBE2C is potentially developed as a therapeutic target for patients with LUAD.

Unveiling ficolins: diagnostic and prognostic biomarkers linked to the Tumor Microenvironment in Lung Cancer

BackgroundFicolins (FCNs) are a family of proteins, comprising FCN1, FCN2 and FCN3, and integral to the immune system which have been implicated in the onset and progression of tumors. Despite their recognized roles, a comprehensive analysis of FCNs in lung cancer remains elusive.MethodsWe employed a variety of bioinformatics tools, including UCSC, SangerBox, Ualcan, cBioPortal, String, Metascape, GeneMANIA, TIDE, CTD, and CAMP databases to investigate the differential expression, diagnostic and prognostic significance, genetic alterations, functional enrichment, immune infiltration, and potential immunotherapeutic implications of FCN1, FCN2, and FCN3 in lung squamous cell carcinoma (LUSC) and lung adenocarcinoma (LUAD). Additionally, RT-qPCR and immunohistochemistry were utilized to validate the expressions of FCNs at the mRNA and protein levels in LUSC and LUAD.ResultsOur comprehensive bioinformatic analysis, supported by RT-qPCR and immunohistochemistry, revealed that the expressions of FCN1, FCN2 and FCN3 were consistently downregulated in both LUSC and LUAD tumor tissues. FCNs demonstrated significant diagnostic potential for LUSC and LUAD, with the area under the receiver operating characteristic curve (AUC) for FCN1 and FCN3 exceeding 0.90. Furthermore, FCN2 and FCN3 showed a strong negative correlation with overall survival (OS) in LUSC, whereas FCN1 and FCN2 were positively correlated with OS in LUAD, suggesting their prognostic value in lung cancer. Gene enrichment analysis indicated that FCNs were predominantly associated with the complement system and complement activation pathways. Immune infiltration analysis further revealed a significant positive correlation between FCNs and the presence of neutrophils and resting mast cells. Our analysis of immunotherapy outcomes revealed a significant disparity in the immunophenoscore (IPS) among lung cancer patients treated with immune checkpoint inhibitors (ICIs), distinguishing those with high FCN expression from those with low FCN expression. Additionally, we identified small molecule compounds related to FCNs and drugs pertinent to LUSC and LUAD.ConclusionFCNs held promise as diagnostic and prognostic biomarkers for LUSC and LUAD. This study also elucidated the relationship of FCNs with the tumor microenvironment, offering novel insights into the immunotherapeutic landscape for LUSC and LUAD.

Histopathologic pattern and molecular risk stratification are associated with prognosis in patients with stage IB lung adenocarcinoma.

The benefit of adjuvant therapy remains controversial in completely resected (R0) stage IB non-small cell lung cancer (NCLSC) patients. In this study, we aimed to explore potential prognostic factors in stage IB NSCLC patients. This study included 215 patients with R0 stage IB lung adenocarcinoma (LUAD) (tumor size: 3-4 cm). DNA sequencing was performed with surgical samples of 126 patients using a panel of 9 driver genes. The molecular risk stratification was assessed by a 14-gene quantitative polymerase chain reaction assay. Among the 215 patients, 67.9% had micropapillary/solid (MIP/SOL)-predominant tumors. Epidermal growth factor receptor (EGFR) mutations were detected in 75 of 126 patients (59.5%). MIP/SOL tumors harbored less common EGFR mutations than the other histologic patterns (50.6% vs. 79.5%, P=0.003). Molecular risk stratification was successfully assessed in 99 patients, of whom 37.4%, 26.3%, and 36.4% were high, intermediate, and low risk, respectively. The MIP/SOL pattern was associated with shorter disease-free survival (DFS) [hazard ratio (HR) =2.16, 95% confidence interval: 1.28-3.67; P=0.01]. The molecular high-risk patients had shorter DFS than the low- (HR =2.93, P=0.01) and intermediate-risk patients (HR =2.35, P=0.06). The prognostic value of molecular risk stratification was also significant in the MIP/SOL subset (median DFS high-risk: 45 months, low and intermediate risk: not reached; P=0.03). Our study showed that both the MIP/SOL pattern and molecular high-risk category were adverse prognostic factors in stage IB NSCLC patients. Our results suggest that combining histologic classification and molecular risk stratification may help to identify the subset of patients with poor prognosis.

Selective loss of Y chromosomes in lung adenocarcinoma modulates the tumor immune environment through cancer/testis antigens.

There is increasing recognition that the sex chromosomes, X and Y, play an important role in health and disease that goes beyond the determination of biological sex. Loss of the Y chromosome (LOY) in blood, which occurs naturally in aging men, has been found to be a driver of cardiac fibrosis and heart failure mortality. LOY also occurs in most solid tumors in males and is often associated with worse survival, suggesting that LOY may give tumor cells a growth or survival advantage. We analyzed LOY in lung adenocarcinoma (LUAD) using both bulk and single-cell expression data and found evidence suggesting that LOY affects the tumor immune environment by altering cancer/testis antigen expression and consequently facilitating tumor immune evasion. Analyzing immunotherapy data, we show that LOY and changes in expression of particular cancer/testis antigens are associated with response to pembrolizumab treatment and outcome, providing a new and powerful biomarker for predicting immunotherapy response in LUAD tumors in males.

Abstract PR-15: Identifying synergistic combinations with KRAS inhibition in PDAC

Abstract Background: To date, targeted therapies have largely failed in eliciting sustained responses in advanced pancreatic ductal adenocarcinoma (PDAC). KRAS-targeted therapies have the potential to drastically transform clinical management. Emerging data indicate that only a subset of patients respond, and that acquired resistance is common. Here, we used a combination of in vivo CRISPR activation (CRISPRa) screening and in vitro/preclinical models to identify synergistic combinations with KRAS inhibition (KRASi) in pancreatic and lung cancer. Material and Methods: We used our CRISPRa-competent PPKS (P53(F/F), Kras(LSL-G12D/+), R26(LSL-SAM)) model of adenocarcinoma to conduct targeted screening for drivers of resistance to MRTX133. Our library consisted of ∼450 frequently mutated and amplified putative oncogenes across human adenocarcinoma based on TCGA data. Mice were treated with 1e8 TU of lentiviral library through nasal instillation. After 6 weeks, treatment was initiated with 3 mg/kg MRTX1133 daily, 5 days/week (i.p.). Mice were sacrificed after 4 weeks of treatment and the guide distribution determined through bioinformatic analysis. Genes statistically significantly enriched (FDR&amp;lt;0.05) in the treatment group were determined. Cell lines with acquired resistance to MRTX1133 derived from the KPC PDAC model and the KPP lung adenocarcinoma (LUAD) model were generated using long-term, low-dose treatment. Resistance was confirmed with MTT drug response assays. In vitro combinatorial drug response was determined using a 72h, 96-well MTT assay, and clonogenic response using a 2 week, 384-well FACS assay. Mice were treated with 20 mg/kg MRTX1133 and/or 20mg/kg Temuterkib once daily, 7 days/week (i.p.) for 2 weeks. Results: We performed targeted in vivo CRISPRa screening for drivers of resistance to KRASi in an autochthons model of lung adenocarcinoma (LUAD) using a library targeting 452 genes commonly amplified or mutated in cancer. We identified a set of genes that were specifically enriched in at least 50% of tumors treated with MRTX1133, including MAPK1/ERK2. We also generated 16 cell lines with acquired resistance to MRTX1133, derived from KPC PDAC or KPP LUAD tumors. Transcriptomic analysis identified a large set of genes differentially expressed in cell with acquired resistance relative to controls. GSEA indicated that reactivation of the MAPK cascade as a common trait in resistant cells. To test if ERK inhibition synergizes with KRASi, we quantified the combinatorial response to MRTX1133 and Temuterkib, a specific inhibitor of ERK1 and ERK2, in a set of KPC and KPP derived cell lines, revealing significant synergy and reduced clonogenic potential in a majority of cell lines. A majority of cell lines with acquired resistance to MRTX1133 remained sensitive to Temuterkib. Finally, we tested combinatorial treatment of MRTX1133 and Temuterkib in a syngenetic subcutaneous model of PDAC, which showed at minimum additive effect. In conclusion we have identified ERK inhibition as a promising combination with KRAS inhibition in KRAS-mutant PDAC and LUAD. Citation Format: Fredrik I Thege, Amber Hoskins, Sonja M Woermann, Anirban Maitra. Identifying synergistic combinations with KRAS inhibition in PDAC [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr PR-15.

GABA(A) Receptor Activation Drives GABARAP-Nix Mediated Autophagy to Radiation-Sensitize Primary and Brain-Metastatic Lung Adenocarcinoma Tumors.

In non-small cell lung cancer (NSCLC) treatment, radiotherapy responses are not durable and toxicity limits therapy. We find that AM-101, a synthetic benzodiazepine activator of GABA(A) receptor, impairs the viability and clonogenicity of both primary and brain-metastatic NSCLC cells. Employing a human-relevant ex vivo 'chip', AM-101 is as efficacious as docetaxel, a chemotherapeutic used with radiotherapy for advanced-stage NSCLC. In vivo, AM-101 potentiates radiation, including conferring a significant survival benefit to mice bearing NSCLC intracranial tumors generated using a patient-derived metastatic line. GABA(A) receptor activation stimulates a selective-autophagic response via the multimerization of GABA(A) receptor-associated protein, GABARAP, the stabilization of mitochondrial receptor Nix, and the utilization of ubiquitin-binding protein p62. A high-affinity peptide disrupting Nix binding to GABARAP inhibits AM-101 cytotoxicity. This supports a model of GABA(A) receptor activation driving a GABARAP-Nix multimerization axis that triggers autophagy. In patients receiving radiotherapy, GABA(A) receptor activation may improve tumor control while allowing radiation dose de-intensification to reduce toxicity.