Poor Prognosis In Lung Adenocarcinoma Patients Research Articles

Integrin β8 Facilitates Macrophage Infiltration and Polarization by Regulating CCL5 to Promote LUAD Progression.

The tumor microenvironment (TME) influences cancer progression and metastasis. Integrin β8 (ITGβ8), a member of the integrin family, is upregulated in various cancers. In this study, it is determined as a key factor that mediates the interaction between lung adenocarcinoma (LUAD) cells and macrophages. Increased expression levels of ITGβ8 are associated with increased numbers of CD163+ macrophages and poor prognosis in LUAD patients. The overexpression of ITGβ8 in LUAD cells promotes the polarization of THP-1 macrophages toward the M2 phenotype. In contrast, TCM (conditioned medium from the co-culture system) from THP-1 macrophages and ITGβ8-overexpressing A549 cells promoted the proliferation and invasion of A549 cells. Mechanistically, chemokine (C-C motif) ligand 5 (CCL5) plays an important role in mediating ITGβ8-induced macrophage polarization, and the phosphoinositide 3-kinase (PI3K)/AKT serine/threonine kinase (AKT)/interferon regulatory factor 9 (IRF9) pathway is involved in this process. Moreover, interleukin 8 (IL8) and interleukin 10 (IL10) produced by M2-like macrophages regulate the expression of ITGβ8 in LUAD cells through the spi-1 proto-oncogene (SPI1). This study elucidates the feedback mechanism of ITGβ8 between LUAD cells and macrophages.

BCAR1 facilitates the survival of lung adenocarcinoma cells by augmenting the unfolded protein response, autophagy, and the formation of vasculogenic mimicry

BackgroundOur objective was to elucidate the pivotal roles of BCAR1 in unfolded protein response (UPR), autophagy and vasculogenic mimicry (VM) formation, processes that essential for the metastasis of lung adenocarcinoma (LUAD) cells. MethodsThe morphological assessment of endoplasmic reticulum (ER) status and autolysosomes in H1975 and H1299 LUAD cells following BCAR1 knockout (KO) was conducted using transmission electron microscope. The expression of markers and cellular functions related to the UPR, autophagy, and VM formation were examined in LUAD cells tissues. Additionally, proteomic analysis of LUAD cells was performed via mass spectrometry, and the pertinent signaling pathways were analyzed using bioinformatics tools. ResultsBCAR1-KO inhibited autophagy and UPR induced triggered starvation in LUAD cells. Cleaved-ATF6a-mediated UPR and subsequent autophagy, enhanced by BCAR1, were confirmed using the UPR stimulator and blocker. High BCAR1 expression, along with elevated UPR and autophagy, predicts poor prognosis in LUAD patients. BCAR1-KO reduced tube formation and VM markers expressions in LUAD cells. Additionally, BCAR1 expression positively correlated with VM formation in BALB/c-nu mice xenografts and LUAD patient tissues. ConclusionBCAR1 promotes LUAD metastasis by enhancing cancer cell survival in nutrient-poor environments through ATF6-mediated UPR activation and autophagy. As BCAR1 induces VM formation, metastatic lesions eventually colonize. Thus, BCAR1 is a promising anti-metastasis target.

Comprehensive analysis identifies YKT6 as a potential prognostic and diagnostic biomarker in lung adenocarcinoma

BackgroundLung cancer is the most common cause of cancer-related death worldwide. The most prevalent histological subtype of lung cancer is lung adenocarcinoma (LUAD), with incidence rising each year. Treating LUAD remains a significant issue due to a lack of early diagnosis and poor therapy outcomes. YKT6 is a member of the SNARE protein family, whose clinical value and biological function in LUAD has yet to be established.MethodsTCGA, HPA and UALCAN were used to analyze YKT6 mRNA and protein levels, the correlation between YKT6 expression and clinicopathological features and prognosis. YKT6 mRNA and protein expression were verified by qRT-PCR, immunohistochemistry (IHC) and tissue microarrays (TMA). Additionally, lung cancer cell lines were chosen for YKT6 silencing to explore the effects on cell proliferation and migration. The cBioPortal was used to select YKT6-related genes. Protein-protein interaction (PPI) network was created based on STRING database and hub genes were screened, with their expression levels and prognosis values in LUAD analyzed accordingly. YKT6-related genes were enriched by gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) analyses.ResultsIn LUAD, YKT6 was distinctly highly expressed with relation to clinical features of staging, smoking, lymph node metastasis, and TP53 mutation. Elevated YKT6 expression was linked to adverse prognosis, serving as an independent unfavorable prognostic factor. Moreover, YKT6 presented high diagnostic value in LUAD patients (AUC = 0.856). Experimental validation indicated that freshly collected LUAD tissues showed significantly high mRNA expression of YKT6. IHC and TMA verified increased YKT6 protein level in LUAD. Knockdown of YKT6 inhibited cell proliferation and promoted apoptosis, with mitigated capability of migration and invasion. The top ten hub genes screened by PPI network were highly expressed in LUAD, and significantly associated with poor prognosis. GO and KEGG analyses showed that YKT6-related genes were mainly involved in cell cycle.ConclusionElevated YKT6 expression is related to poor prognosis of LUAD patients. YKT6 can serve as a novel biomarker for LUAD diagnosis and prognosis. Cell proliferation, migration and invasion was impaired with increased apoptosis upon YKT6 silencing in lung cancer cells. In summary, this study comprehensively uncovered that YKT6 could be identified as a potential prognostic and diagnostic biomarker in LUAD.

PARD6A promotes lung adenocarcinoma cell proliferation and invasion through Serpina3.

Par6α encoded by PARD6A is a member of the PAR6 family and is reported to promote cancer initiation and progression. PARD6A is frequently upregulated in different types of cancers, but its regulatory role in lung cancer progression is yet to be established. In this study, we analyzed the PARD6A expression in biopsies from lung adenocarcinoma (LUAD) patients, and the survival probability using LUAD tissue microarray (TMA) and online datasets from TCGA and GEO. We conducted in vitro and in vivo assays to assess the role of PARD6A in regulating lung cancer progression, including proliferation, wound healing, transwell, RNA-seq, and subcutaneous tumor mice models. Our findings revealed that PARD6A is highly expressed in cancer tissues from LUAD patients and is associated with poor prognosis in LUAD patients. In vitro assays showed that PARD6A promoted cell proliferation, migration, and invasion. The transcriptome sequencing identified Serpina3 as one of the key downstream molecules of PARD6A. Ectopic expression of Serpina3 rescued impaired proliferation, migration, and invasion in PARD6A-knocking down H1299 cells, whereas silencing Serpina3 impeded enhanced proliferation, migration, and invasion in PARD6A-overexpressing H1975 cells. Our findings suggest that PARD6A promotes lung cancer progression by inducing Serpina3, which may be a promising therapeutic target.

6-Phosphogluconate dehydrogenase promotes glycolysis and fatty acid synthesis by inhibiting the AMPK pathway in lung adenocarcinoma cells

Abnormal metabolism has emerged as a prominent hallmark of cancer and plays a pivotal role in carcinogenesis and progression of lung adenocarcinoma (LUAD). In this study, single-cell sequencing revealed that the metabolic enzyme 6-phosphogluconate dehydrogenase (PGD), which is a critical regulator of the pentose phosphate pathway (PPP), is significantly upregulated in the malignant epithelial cell subpopulation during malignant progression. However, the precise functional significance of PGD in LUAD and its underlying mechanisms remain elusive. Through the integration of TCGA database analysis and LUAD tissue microarray data, it was found that PGD expression was significantly upregulated in LUAD and closely correlated with a poor prognosis in LUAD patients. Moreover, in vitro and in vivo analyses demonstrated that PGD knockout and inhibition of its activity mitigated the proliferation, migration, and invasion of LUAD cells. Mechanistically, immunoprecipitation-mass spectrometry (IP-MS) revealed for the first time that IQGAP1 is a robust novel interacting protein of PGD. PGD decreased p-AMPK levels by competitively interacting with the IQ domain of the known AMPKα binding partner IQGAP1, which promoted glycolysis and fatty acid synthesis in LUAD cells. Furthermore, we demonstrated that the combination of Physcion (a PGD-specific inhibitor) and metformin (an AMPK agonist) could inhibit tumor growth more effectively both in vivo and in vitro. Collectively, these findings suggest that PGD is a potential prognostic biomarker and therapeutic target for LUAD.

SGPP2 is activated by SP1 and promotes lung adenocarcinoma progression.

The late diagnosis and easy metastasis of lung adenocarcinoma (LADC) remains a challenge. SGPP2 is reported to modulate cell processes in many cancers. However, the roles and molecular mechanisms of SGPP2 in LADC are unclear. Online bioinformatics tools GEPIA, CPTAC, and K-M plotter were used to analyze the expression of SGPP2 and the prognosis in LADC. JASPAR and PROMO were used to predict the transcription factors of SGPP2. Real-time quantitative reverse transcription PCR and western blot were used to detect the levels of SGPP2 in LADC cell lines and tissues. Cell counting kit-8, colony formation, flow cytometry, and transwell assay were used to detect cell proliferation, apoptosis, and invasion. The anti-cancer effect of SGPP2 silence was evaluated in the LADC xenograft model. It was found that SGPP2 was highly expressed and related to the poor prognosis of LADC patients. Elevated SGPP2 expression was detected in LADC cell lines and tissues. The chi-square test indicated that the expression of SGPP2 was positively related to tumor, node, metastasis grades and lymph node metastasis. Knocking down SGPP2 significantly inhibited LADC cell viability, and invasion, but induced apoptosis. The anti-tumor effects of SGPP2 were verified in vivo. The upstream transcription factor of SGPP2 was predicted to be SP1, which was highly expressed in LADC tissues and cell lines. Overexpression of SP1 partly rescued the inhibition of SGPP2-shRNA in cell growth, colony formation, and invasion capabilities, and decreased apoptotic cell number in LADC cells. This study demonstrated that SGPP2, activated by SP1, promotes LADC cell proliferation and invasion, and suppresses apoptosis in LADC.

The deubiquitinating protein OTUD6B promotes lung adenocarcinoma progression by stabilizing RIPK1

BackgroundThere is growing evidence indicating that deubiquitinating enzymes may contribute to tumor progression and can serve as promising therapeutic targets.MethodsThe overexpression of deubiquitinase OTUD6B in lung adenocarcinoma (LUAD) and its adjacent tissues was analyzed by immunohistochemistry and TCGA/GO database. Survival analysis further supported OTUD6B as a potential target for LUAD treatment. We assessed the effect of OTUD6B on LUAD cell growth using cell viability assays and conducted TUNEL staining, migration, and invasion experiments to investigate the impact of OTUD6B on the apoptosis and metastasis of LUAD cells. Additionally, we established a transplanted tumor model in nude mice to validate our findings in vivo. Finally, using IP mass spectrometry and co-IP experiments, we screened and confirmed the influence of RIPK1 as a substrate of OTUD6B in LUAD.ResultsOTUD6B is highly overexpressed in human LUAD and predicts poor prognosis in LUAD patients. OTUD6B knockdown inhibited the proliferation of LUAD cells and enhanced apoptosis and inhibited metastasis in LUAD cells suppressed. A549 xenografts revealed that OTUD6B deletion can slow down tumour growth. Additionally, OTUD6B can bind to RIPK1, reduce its ubiquitination level and increase its protein stability.ConclusionsOur results suggest that OTUD6B is a promising clinical target for LUAD treatment and that targeting OTUD6B may constitute an effective anti-LUAD strategy.

Significance of Ribonucleoside-diphosphate Reductase Subunit M2 in Lung Adenocarcinoma.

The Ribonucleoside-diphosphate Reductase subunit M2 (RRM2) is known to be overexpressed in various cancers, though its specific functional implications remain unclear. This aims to elucidate the role of RRM2 in the progression of Lung Adenocarcinoma (LUAD) by exploring its involvement and potential impact. RRM2 data were sourced from multiple databases to assess its diagnostic and prognostic significance in LUAD. We evaluated the association between RRM2 expression and immune cell infiltration, analyzed its function, and explored the effects of modulating RRM2 expression on LUAD cell characteristics through laboratory experiments. RRM2 was significantly upregulated in LUAD tissues and cells compared to normal counterparts (p<0.05), with rare genetic alterations noted (approximately 2%). This overexpression clearly distinguished LUAD from normal tissue (area under the curve (AUC): 0.963, 95% confidence intervals (CI): 0.946-0.981). Elevated RRM2 expression was significantly associated with adverse clinicopathological characteristics and poor prognosis in LUAD patients. Furthermore, a positive association was observed between RRM2 expression and immune cell infiltration. Pathway analysis revealed a critical connection between RRM2 and the cell cycle signaling pathway within LUAD. Targeting RRM2 inhibition effectively suppressed LUAD cell proliferation, migration, and invasion while promoting apoptosis. This intervention also modified the expression of several crucial proteins, including the downregulation of CDC25A, CDC25C, RAD1, Bcl-2, and PPM1D and the upregulation of TP53 and Bax (p < 0.05). Our findings highlight the potential utility of RRM2 expression as a biomarker for diagnosing and predicting prognosis in LUAD, shedding new light on the role of RRM2 in this malignancy.

Downregulation of DIP2B as a prognostic marker inhibited cancer proliferation and migration and was associated with immune infiltration in lung adenocarcinoma via CCND1 and MMP2

BackgroundDIP2B is related to cancer progression. This study investigated the roles and pathways of DIP2B in lung adenocarcinoma (LUAD). MethodsDIP2B expression and the relationship between survival time of cancer patients and DIP2B expression were analyzed. The relationship between DIP2B expression and survival time in LUAD patients was evaluated by a meta-analysis. Cox and survival analyses were used to evaluate the prognostic factors and construct a prognostic nomogram. The mechanisms and effects of DIP2B and the relationship between DIP2B expression and the immune microenvironment were investigated using bioinformatics, CCK-8, western blotting, and transwell experiments. ResultsDIP2B was overexpressed in LUAD tissues. DIP2B overexpression was associated with shorter prognosis and was an unfavorable risk factor for prognosis in LUAD patients. DIP2B co-expressed genes were involved in cell division, DNA repair, cell cycle, and others. Inhibition of DIP2B expression could downregulate the proliferation, migration, and invasion of LUAD A549 and H1299 cells, which was related to the decrease in CCND1 and MMP2 protein expression. BRCA1 overexpression was associated with short prognosis, and the nomogram formed by DIP2B and BRCA1 was associated with a poor prognosis in LUAD patients. DIP2B expression correlated with immune cells (such as CD8 T cells, Tcm, and iDCs) and cell markers. ConclusionDIP2B is a potential biomarker of poor prognosis and the immune microenvironment in LUAD. Inhibition of DIP2B expression downregulated cancer cell proliferation, migration, and invasion, which might be related to the decrease in CCND1 and MMP2 protein expression. DIP2B-related nomograms might be useful tools for predicting the prognosis of LUAD patients.

Phosphorylation of LZTS2 by PLK1 activates the Wnt pathway

Lung adenocarcinoma (LUAD), responsible for nearly half of lung cancer cases, is one of the most prevalent and lethal malignant tumors globally. There is increasing evidence suggesting that the oncoprotein PLK1 plays a role in the onset and advancement of different types of cancer, including LUAD. Nonetheless, the precise mechanism by which PLK1 promotes tumorigenesis remains unclear. In this study, we demonstrate the upregulation of PLK1 in LUAD samples, which leads to a poor prognosis for LUAD patients. Intriguingly, PLK1 enables to bind to LZTS2 and promote its phosphorylation without affecting LZTS2 degradation. Furthermore, we identify that Ser451 is a key phosphorylation site in LZTS2 protein. LZTS2 exerts an anti-tumor effect by restricting the translocation of the transcription factor β-Catenin into the nucleus, thereby suppressing the Wnt pathway. PLK1 disrupts the interaction between LZTS2 and β-Catenin, resulting in the nuclear accumulation of β-Catenin and the activation of the Wnt pathway. Additionally, we reveal that LZTS2 inhibits the proliferation and migration of LUAD cells, which is rescued by PLK1. Finally, PLK1 inhibitors exhibit a dose-dependent suppression of LUAD cell proliferation and migration. Collectively, this study uncovers the pro-tumorigenic mechanism of PLK1, positioning it as a promising therapeutic target for Wnt-related LUAD.

TMEM9 promotes lung adenocarcinoma progression via activating the MEK/ERK/STAT3 pathway to induce VEGF expression

Abnormal Transmembrane protein 9 (TMEM9) expression has been identified in various human tumors. However, the prognostic potential and mechanistic role of TMEM9 in lung adenocarcinoma (LUAD) remain unclear. Here, we first found a significant upregulation of TMEM9 in LUAD tissues, and TMEM9 expression was positively correlated with microvessel density (MVD), T stage, and clinical stage. Survival analysis demonstrated TMEM9 was an independent indicator of poor prognosis in LUAD patients. In addition, downregulation of TMEM9 suppressed tumor growth and metastasis in vitro and in vivo models, and reduced HUVEC proliferation, migration, and tube formation in a cancer cell/HUVEC coculture model. Furthermore, TMEM9 upregulated VEGF expression, and VEGF-neutralizing antibodies reversed HUVEC angiogenesis and cancer cell migration ability caused by overexpression of TMEM9. In contrast, recombinant VEGF (rVEGF) abolished the inhibitory effect of TMEM9-knockdown LUAD cells on HUVEC angiogenesis and tumor cell migration. Moreover, we showed that TMEM9 upregulated VEGF expression by activating the mitogen-activated protein kinase/extracellular signal-regulated kinase/STAT3 (MEK/ERK/STAT3) pathway. Together, our study provides mechanistic insights into the role of TMEM9 in LUAD and highlights the potential of targeting the TMEM9/MEK/ERK/STAT3/VEGF pathway as a novel therapy for preventing LUAD progression.

FBXO32-mediated degradation of PTEN promotes lung adenocarcinoma progression.

FBXO32, a member of the F-box protein family, is known to play both oncogenic and tumor-suppressive roles in different cancers. However, the functions and the molecular mechanisms regulated by FBXO32 in lung adenocarcinoma (LUAD) remain unclear. Here, we report that FBXO32 is overexpressed in LUAD compared with normal lung tissues, and high expression of FBXO32 correlates with poor prognosis in LUAD patients. Firstly, we observed with a series of functional experiments that FBXO32 alters the cell cycle and promotes the invasion and metastasis of LUAD cells. We further corroborate our findings using in vivo mouse models of metastasis and confirmed that FBXO32 positively regulates LUAD tumor metastasis. Using a proteomic-based approach combined with computational analyses, we found a positive correlation between FBXO32 and the PI3K/AKT/mTOR pathway, and identified PTEN as a FBXO32 interactor. More important, FBXO32 binds PTEN via its C-terminal substrate binding domain and we also validated PTEN as a bona fide FBXO32 substrate. Finally, we demonstrated that FBXO32 promotes EMT and regulates the cell cycle by targeting PTEN for proteasomal-dependent degradation. In summary, our study highlights the role of FBXO32 in promoting the PI3K/AKT/mTOR pathway via PTEN degradation, thereby fostering lung adenocarcinoma progression.

Abstract 4372: Epithelial-to-mesenchymal transition-driven secretory program underlies vulnerabilities in lung cancer

Abstract Epithelial-to-mesenchymal transition (EMT) is a driving force behind lung adenocarcinoma (LUAD) progression. Although substantial evidence has been attained in the involvement of EMT and its regulatory mechanisms in cancer, few effective EMT-targeted therapies have been available in the clinic thus far. It is urgent to develop new therapeutic strategies for improving patient outcomes. We have identified RAB6A as a master regulator of EMT-driven secretory trafficking, which coordinates cancer cell invasion and immunosuppression in LUAD. We found that RAB6A expression was associated with a poor prognosis in LUAD patients and that RAB6A inhibition in our LUAD models reversed resistance to immune checkpoint inhibition with PD-L1 blockade, an emerging clinical problem. Thus, RAB6A machinery is a therapeutic target of interest in EMT-driven cancers. Screening approaches to identify selective RAB inhibitors are in their infancy, a challenge that can be overcome only by obtaining insights into the regulation of RAB6A. RAB6A is a small GTPase whose activity is controlled by guanine nucleotide exchange factors (GEFs) like RIC1 and RGP1, and GTPase activating proteins (GAPs) like RABGAP1, as well as other effector proteins. While these GEFs, GAPs, and effectors are all known regulators of RAB6A function and are frequently amplified in different cancer types, their specific functions in cancer progression are still unknown. To establish the causal relationship between these proteins and EMT-driven LUAD progression, we utilize human and murine LUAD cell lines that have been characterized with respect to EMT status. Our findings here show that the intervention of RAB6A activity via depletion of these regulators impairs the recruitment of RAB6A to the Golgi. We demonstrate that knocking down the GEFs, RIC1 and RGP1, significantly decreases invasion while having negligible effects on the migrative and proliferative abilities of these cells. RABGAP1 depletion, on the other hand, reduces cell proliferation but has no effects on the migration and invasion of the cells. Consistent with these results, inactivation of RAB6A abolishes the EMT-dependent pro-metastatic secretion. Mechanistically, the EMT activator, ZEB1, upregulates RGP1 via silencing miR-148a that targets this GEF to activate RAB6A. These findings elucidate the regulatory mechanisms underlying the EMT-driven secretory program, providing a foundation for therapeutic intervention to prevent the progression of LUAD. Citation Format: Kevin L. Fulp, Oluwafunminiyi E. Obaleye, Guan-Yu Xiao. Epithelial-to-mesenchymal transition-driven secretory program underlies vulnerabilities in 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 4372.

Abstract 205: Adaptive membrane trafficking activated by epithelial-to-mesenchymal transition drives lung adenocarcinoma progression

Abstract Cancer cells can become metastatic and develop resistance to targeted therapies through epithelial-to-mesenchymal transition (EMT), which is regulated by epigenetic factors. Our ultimate objective is to understand the molecular mechanisms behind EMT-driven cancer progression and identify potential targets for preventing cancer metastasis. Recently, we made groundbreaking discoveries indicating that EMT can modify membrane trafficking machinery to coordinate cancer cell invasion and immunosuppression in the tumor microenvironment (TME) of lung adenocarcinoma (LUAD). To dissect the “adaptive” membrane trafficking program, we initiated a CRISPRi in vivo screen to assess more than 2000 trafficking-related genes in syngeneic mouse LUAD models for their requirements for tumorigenesis both with and without immune selective pressure. We identified a panel of membrane trafficking regulators that specifically “dropped out” in immunocompetent mice, suggesting their essential roles in the immunosuppressive TME. Of particular interest is REEP2. REEPs are an evolutionarily conserved protein family that is critical to the endoplasmic reticulum (ER) function and potentially regulates secretory trafficking. We discovered that REEP2 is specifically linked to poor prognosis in LUAD patients and is highly correlated with a z-normalized, 16-gene EMT score (P = 1.32e-27) that was previously reported. Our previous studies demonstrated that the EMT activator, ZEB1, accelerates membrane trafficking dynamics by silencing a microRNA network that targets multiple membrane trafficking components. Analysis of REEP2 3’-untranslated regions (3’-UTRs) identified predicted binding sites for several microRNAs, which are silenced by ZEB1. Thus, we hypothesize that ZEB1 coordinates a microRNA network to activate REEP2-driven ER trafficking. We show that REEP2 depletion significantly reduces the invasion of cancer cells but does not affect their migration and proliferation. These findings suggest that REEP2 plays a significant role in extracellular matrix (ECM) modification to enhance the invasion of metastatic cells, conferring a vulnerability in EMT-driven LUAD metastasis. Citation Format: Oluwafunminiyi E. Obaleye, Kevin L. Fulp, Guan-Yu Xiao. Adaptive membrane trafficking activated by epithelial-to-mesenchymal transition drives lung adenocarcinoma progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 205.

JAM2 is a prognostic biomarker and inhibits proliferation, metastasis and epithelial-mesenchymal transition in lung adenocarcinoma.

Junctional adhesion molecule 2 (JAM2) plays a pivotal role in various biological processes, including proliferation, metastasis and angiogenesis, contributing to tumor progression. While previous studies have highlighted the polarizing functions of JAM2 in different cancer types, its specific role in lung adenocarcinoma (LUAD) remains unclear. In this study, we harnessed multiple public databases to analyze the expression and prognostic significance of JAM2 in LUAD. Using the Linkedomics database, Matescape database and R package, we explored the associated genes, the potential biological functions and the impact of JAM2 on the tumor microenvironment. Our findings from public databases were further validated using real-time quantitative PCR, western blot and immunohistochemistry. Additionally, in vitro experiments were conducted to assess the influence of JAM2 on LUAD cell proliferation, invasion, migration, apoptosis and epithelial-mesenchymal transition. Furthermore, we established a xenograft model to investigate the in vivo effects of JAM2 on tumorigenesis. Our results revealed a significant downregulation of JAM2 in LUAD, and patients with low JAM2 expression exhibited unfavorable overall survival outcomes. Functional enrichment analysis indicated that JAM2 may be associated with processes such as cell adhesion, extracellular matrix, cell junctions and regulation of proliferation. Notably, increased JAM2 expression correlated with higher tumor microenvironment scores and reduced immune cell abundance. Furthermore, overexpression of JAM2 induced apoptosis, suppressed tumor proliferation and exhibited potential inhibitory effects on tumor invasion and migration through the modulation of epithelial-mesenchymal transition. Additionally, in vivo experiments confirmed that JAM2 overexpression led to a reduction in tumor growth. Overall, our study highlights the clinical significance of low JAM2 expression as a predictor of poor prognosis in LUAD patients. Moreover, JAM2 was found to exert inhibitory effects on various aspects of tumor progression. Consequently, JAM2 emerges as a promising prognostic biomarker and a potential therapeutic target for LUAD patients.

TRIP13 Enhances Radioresistance of Lung Adenocarcinoma Cells through the Homologous Recombination Pathway

Radiation therapy is one of the most common treatments for non-small cell lung cancer (NSCLC). However, the insensitivity of some tumor cells to radiation is one of the major reasons for the poor efficacy of radiotherapy and the poor prognosis of patients, and exploring the underlying mechanisms behind radioresistance is the key to solving this clinical challenge. This study aimed to identify the molecules associated with radioresistance in lung adenocarcinoma (LUAD), identified thyroid hormone receptor interactor 13 (TRIP13) as the main target initially, and explored whether TRIP13 is related to radioresistance in LUAD and the specific mechanism, with the aim of providing theoretical basis and potential targets for the combination therapy of LUAD patients receiving radiotherapy in the clinic. Three datasets, GSE18842, GSE19188 and GSE33532, were selected from the Gene Expression Omnibus (GEO) database and screened for differentially expressed genes (|log FC|>1.5, P<0.05) in each of the three datasets using the R 4.1.3 software, and then Venn diagram was used to find out the differentially expressed genes common to the three datasets. The screened differential genes were then subjected to protein-protein interaction (PPI) analysis and module analysis with the help of STRING online tool and Cytoscape software, and survival prognosis analysis was performed for each gene with the help of Kaplan-Meier Plotter database, and the TRIP13 gene was identified as the main molecule for subsequent studies. Subsequently, the human LUAD cell line H292 was irradiated with multiple X-rays using a sub-lethal dose irradiation method to construct a radioresistant cell line, H292DR. The radioresistance of H292DR cells was verified using cell counting kit-8 (CCK-8) assay and clone formation assay. The expression levels of TRIP13 in H292 and H292DR cells were measured by Western blot. Small interfering RNA (siRNA) was used to silence the expression of TRIP13 in H292DR cells and Western blot assay was performed. The clone formation ability and migration ability of H292DR cells were observed after TRIP13 silencing, followed by the detection of changes in the expression levels of proteins closely related to homologous recombination, such as ataxia telangiectasia mutated (ATM) protein. Screening of multiple GEO datasets, validation of external datasets and survival analysis revealed that TRIP13 was highly expressed in LUAD and was associated with poor prognosis in LUAD patients who had received radiation therapy. And the results of gene set enrichment analysis (GSEA) of TRIP13 suggested that TRIP13 might be closely associated with LUAD radioresistance by promoting homologous recombination repair after radiation therapy. Experimentally, TRIP13 expression was found to be upregulated in H292DR, and silencing of TRIP13 was able to increase the sensitivity of H292DR cells to radiation. TRIP13 is associated with poor prognosis in LUAD patients treated with radiation, possibly by promoting a homologous recombination repair pathway to mediate resistance of LUAD cells to radiation.

Identification and Analysis of SND1 as an Oncogene and Prognostic Biomarker for Lung Adenocarcinoma

Transcription factor (TF) can bind specific sequences that either promotes or represses the transcription of target genes, and exerts important effects on tumorigenesis, migration, invasion. Staphylococcal nuclease-containing structural domain 1 (SND1), which is a transcriptional co-activator, is considered as a promising target for tumor therapy. However, its role in lung adenocarcinoma (LUAD) remains unclear. This study aims to explore the role of SND1 in LUAD. Data from The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO), Clinical Proteomic Tumor Analysis Consortium (CPTAC), and Human Protein Atlas (HPA) database was obtained to explore the association between SND1 and the prognosis, as well as the immune cell infiltration, and subcellular localization in LUAD tissues. Furthermore, the functional role of SND1 in LUAD was verified in vitro. EdU assay, CCK-8 assay, flow cytometry, scratch assay, Transwell assay and Western blot were performed. SND1 was found to be upregulated and high expression of SND1 is correlated with poor prognosis of LUAD patients. In addition, SND1 was predominantly present in the cytoplasm of LUAD cells. Enrichment analysis showed that SND1 was closely associated with the cell cycle, as well as DNA replication, and chromosome segregation. Immune infiltration analysis showed that SND1 was closely associated with various immune cell populations, including T cells, B cells, cytotoxic cells and dendritic cells. In vitro studies demonstrated that silencing of SND1 inhibited cell proliferation, invasion and migration of LUAD cells. Besides, cell cycle was blocked at G1 phase by down-regulating SND1. SND1 might be an important prognostic biomarker of LUAD and may promote LUAD cells proliferation and migration.

Acetyltransferase P300 Regulates Glucose Metabolic Reprogramming through Catalyzing Succinylation in Lung Cancer.

Aberrant protein post-translational modification is a hallmark of malignant tumors. Lysine succinylation (Ksucc) plays a vital role in cell energy metabolism in various cancers. However, whether succinylation can be catalyzed by acetyltransferase p300 remains unclear. In this study, we unveiled that p300 is a "writer" for succinylation, and p300-mediated Ksucc promotes cell glycometabolism in lung adenocarcinoma (LUAD). Specifically, our succinylome data revealed that EP300 deficiency leads to the systemic reduction of Ksucc, and 79.55% of the p300-succinylated proteins were found in the cytoplasm, which were primarily enriched in the carbohydrate metabolism process. Interestingly, deleting EP300 led to a notable decrease in Ksucc levels on several glycolytic enzymes, especially Phosphoglycerate Kinase 1 (PGK1). Mutation of the succinylated site of PGK1 notably hindered cell glycolysis and lactic acid excretion. Metabolomics in vivo indicated that p300-caused metabolic reprogramming was mainly attributed to the altered carbohydrate metabolism. In addition, 89.35% of LUAD patients exhibited cytoplasmic localization of p300, with higher levels in tumor tissues than adjacent normal tissues. High levels of p300 correlated with advanced tumor stages and poor prognosis of LUAD patients. Briefly, we disclose the activity of p300 to catalyze succinylation, which contributes to cell glucose metabolic reprogramming and malignant progression of lung cancer.

Construction of shared gene signature between rheumatoid arthritis and lung adenocarcinoma helps to predict the prognosis and tumor microenvironment of the LUAD patients.

Introduction: Rheumatoid arthritis (RA) is a common chronic autoimmune disease with high incidence rate and high disability rate. One of the top complications is cancer, especially lung adenocarcinoma (LUAD). However, the molecular mechanisms linking RA and LUAD are still not clear. Therefore, in this study, we tried to identify the shared genetic signatures and local immune microenvironment between RA and LUAD and construct a clinical model for survival prediction. Methods: We obtained gene expression profiles and clinical information of patients with RA and LUAD from GEO and TCGA datasets. We performed differential analysis and Weighted Gene Co-expression Network Analysis (WGCNA) to discover the shared genes between RA and LUAD. Then, COX regression and LASSO analysis were employed to figure out genes significantly associated with survival. qRT-PCR and Western blot were utilized to validate the expression level of candidate genes. For clinical application, we constructed a nomogram, and also explored the value of RALUADS in characterizing immune infiltration features by CIBERSORT and xCell. Finally, responses to different drug therapy were predicted according to different RALUADS. Results: Our analysis identified two gene sets from differentially expressed genes and WGCNA gene modules of RA and LUAD. Filtered by survival analysis, three most significant shared genes were selected, CCN6, CDCA4 and ERLIN1, which were all upregulated in tumors and associated with poor prognosis. The three genes constituted RA and LUAD score (RALUADS). Our results demonstrated that RALUADS was higher in tumor patients and predicted poor prognosis in LUAD patients. Clinical nomogram combining RALUADS and other clinicopathological parameters had superior performance in survival prediction (AUC = 0.722). We further explored tumor immune microenvironment (TME) affected by RALUADS and observed RALUADS was closely related to the sensitivity of multiple immune blockades, chemotherapy and targeted drugs. Conclusion: Our findings suggest that there are shared physiopathologic processes and molecular profiles between RA and LUAD. RALUADS represents an excellent prognosis predictor and immune-related biomarker, which can be applied to select potential effective drugs and for LUAD patients with RA.

The Interaction of Calcium-Sensing Receptor with KIF11 Enhances Cisplatin Resistance in Lung Adenocarcinoma via BRCA1/cyclin B1 pathway.

Cisplatin (DDP) is commonly used in the treatment of non-small cell lung cancer (NSCLC), including lung adenocarcinoma (LUAD), and the primary cause for its clinical inefficacy is chemoresistance. Here, we aimed to investigate a novel mechanism of chemoresistance in LUAD cells, focusing on the calcium-sensing receptor (CaSR). In this study, high CaSR expression was detected in DDP-resistant LUAD cells, and elevated CaSR expression is strongly correlated with poor prognosis in LUAD patients receiving chemotherapy. LUAD cells with high CaSR expression exhibited decreased sensitivity to cisplatin, and the growth of DDP-resistant LUAD cells was inhibited by cisplatin treatment in combination with CaSR suppression, accompanied by changes in BRCA1 and cyclin B1 protein expression both in vitro and in vivo. Additionally, an interaction between CaSR and KIF11 was identified. Importantly, suppressing KIF11 resulted in decreased protein levels of BRCA1 and cyclin B1, enhancing the sensitivity of DDP-resistant LUAD cells to cisplatin with no obvious decrease in CaSR. Here, our findings established the critical role of CaSR in promoting cisplatin resistance in LUAD cells by modulating cyclin B1 and BRCA1 and identified KIF11 as a mediator, highlighting the potential therapeutic value of targeting CaSR to overcome chemoresistance in LUAD.