Lung Adenocarcinoma Tumor Cells Research Articles

Analyzing the Spatial Distribution of Immune Cells in Lung Adenocarcinoma.

(1) Background: This study investigates the tumor immune microenvironment, focusing on immune cell distribution in lung adenocarcinoma. (2) Methods: We evaluated fifty cases of lung adenocarcinoma, and suitable areas for further studies were annotated on the histological slides. Two tumor cores per case were obtained, one from the tumor's center and another from its periphery, and introduced into three paraffin receptor blocks for optimized processing efficiency. The 4-micrometer-thick tissue microarray sections were stained for H&E and for CD68, CD163, CD8, CD4, and PD-L1; (3) Results: Our investigation revealed significant correlations between PD-L1 expression in tumor cells and the presence of CD163+ macrophages, between CD4+ cells and CD8+, CD68+, and CD163+ cells, and also between CD8+ T cells and CD163+ cells. Additionally, while we observed some differences in cellular components and densities between the tumor center and periphery, these differences were not statistically significant. However, distinct correlations between PD-L1 and immune cells in these regions were identified, suggesting spatial heterogeneity in the immune landscape. (4) Conclusions: These results emphasize the intricate interactions between immune cells and tumor cells in lung adenocarcinoma. Understanding patient spatial immune profile could improve patient selection for immunotherapy, ensuring that those most likely to benefit are identified.

Abstract 5338: Evaluation of checkpoint inhibitor efficacy in a humanized immune system mouse model lacking murine Fc gamma receptors

Abstract Humanized immune system (HIS) mice are critical immuno-oncology tools for evaluating antibody-based therapeutic target engagement and efficacy in a human-like context. Most antibody-based therapeutics have an IgG backbone and thus engage Fc gamma receptors. Traditional HIS mice retain murine immune cells such as neutrophils and macrophages which can interact with human IgG-based therapeutics and confound preclinical results. To determine whether knockout of murine Fc gamma receptors (FcγRs) in a super-immunodeficient mouse model would alter anti-PD1 efficacy compared to the parent strain, we studied tumor growth kinetics, human reconstitution, and tumor infiltrating leukocytes (TILs) in each strain engrafted with HCC827 lung adenocarcinoma tumor cells treated with pembrolizumab or vehicle. Methods: HIS NOG (huNOG) or HIS FcγR knockout NOG mice (FcResolv™ huNOG) were created using identical protocols with CD34+ cells from three human donors shared across both strains. Baseline reconstitution was evaluated in naïve animals via flow cytometry. HCC827 cells were inoculated in remaining animals. Animals were randomized on day 7 post-tumor implantation into 12 groups. Body weight, clinical observations, and tumor growth were measured. Mice received treatment from D7, dosed twice weekly for four weeks, and were then euthanized for FACS analysis, collecting blood, spleen, and tumor samples. Results: For a given donor, no significant differences were seen between strains in human immune reconstitution and kinetics. Pembrolizumab treatment showed significant tumor growth inhibition in one donor in FcResolv huNOG, but not in donor-matched huNOG mice. Evaluation of human TILs in pembrolizumab-treated animals showed significant differences between the strains across all donors, with FcResolv huNOG mice showing increased CD8+ T cells and decreased tumor-associated macrophages compared to vehicle-treated mice, and no significant differences in huNOG. Evaluation of murine TILs revealed differences in murine macrophage populations, regardless of treatment, with Ly6Clo dominant in FcResolv huNOG and Ly6Chi dominant in huNOG. In the presence of pembrolizumab, the murine myeloid and granulocyte population within the spleen is significantly decreased in FcResolv huNOG mice whereas no change was seen in huNOG. Conclusions: Our study demonstrates when treated with anti-PD1, FcResolv huNOG mice show expected pharmacodynamic changes and donor-dependent efficacy whereas, despite identical donors and creation protocols, pembrolizumab-treated huNOG mice showed neither. These differences are due to the presence or absence of murine FcγRs and their impact on antibody IgG-based therapeutics. Citation Format: Nicholas Smith, Monika Buczek, Megan MacBride, Esther Andino, Emily Sack, Debra Freer, Michelle Vedder, Kathleen Bott, Louise Baskin, Damien France, Francis Bichat, Caroline Mignard, Janell Richardson. Evaluation of checkpoint inhibitor efficacy in a humanized immune system mouse model lacking murine Fc gamma receptors [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 5338.

P1.09-04 Characterization of the Immunosuppressive Function of UPP1high Tumor Cells in Lung Adenocarcinoma and Its Association with Immunotherapy

P1.09-04 Characterization of the Immunosuppressive Function of UPP1high Tumor Cells in Lung Adenocarcinoma and Its Association with Immunotherapy

A novel signature predicts prognosis and immunotherapy in lung adenocarcinoma based on cancer-associated fibroblasts.

Extensive research has established the significant correlations between cancer-associated fibroblasts (CAFs) and various stages of cancer development, including initiation, angiogenesis, progression, and resistance to therapy. In this study, we aimed to investigate the characteristics of CAFs in lung adenocarcinoma (LUAD) and develop a risk signature to predict the prognosis of patients with LUAD. We obtained single-cell RNA sequencing (scRNA-seq) and bulk RNA-seq data from the public database. The Seurat R package was used to process the scRNA-seq data and identify CAF clusters based on several biomarkers. CAF-related prognostic genes were further identified using univariate Cox regression analysis. To reduce the number of genes, Lasso regression was performed, and a risk signature was established. A novel nomogram that incorporated the risk signature and clinicopathological features was developed to predict the clinical applicability of the model. Additionally, we conducted immune landscape and immunotherapy responsiveness analyses. Finally, we performed in vitro experiments to verify the functions of EXO1 in LUAD. We identified 5 CAF clusters in LUAD using scRNA-seq data, of which 3 clusters were significantly associated with prognosis in LUAD. A total of 492 genes were found to be significantly linked to CAF clusters from 1731 DEGs and were used to construct a risk signature. Moreover, our immune landscape exploration revealed that the risk signature was significantly related to immune scores, and its ability to predict responsiveness to immunotherapy was confirmed. Furthermore, a novel nomogram incorporating the risk signature and clinicopathological features showed excellent clinical applicability. Finally, we verified the functions of EXP1 in LUAD through in vitro experiments. The risk signature has proven to be an excellent predictor of LUAD prognosis, stratifying patients more appropriately and precisely predicting immunotherapy responsiveness. The comprehensive characterization of LUAD based on the CAF signature can predict the response of LUAD to immunotherapy, thus offering fresh perspectives into the management of LUAD patients. Our study ultimately confirms the role of EXP1 in facilitating the invasion and growth of tumor cells in LUAD. Nevertheless, further validation can be achieved by conducting in vivo experiments.

PCK2 inhibits lung adenocarcinoma tumor cell immune escape through oxidative stress-induced senescence as a potential therapeutic target.

Our research aimed to better understand how phosphoenolpyruvate carboxykinase 2 (PCK2) is linked to survival outcomes in lung cancer patients. We confirmed PCK2 expression and its association with the outcome of lung cancer patients using The Cancer Genome Atlas (TCGA) database. PCK2 and immune cell connections were investigated using data from the Tumor IMmune Estimation Resource (TIMER) and TCGA repositories. We used the CancerSEA database to examine the links between PCK2 expression and the efficiency of lung adenocarcinomas, and a T-distributed Stochastic Neighbor Embedding (T-SNE) map was constructed to show the expression profile of PCK2 in single cells in TCGA lung adenocarcinoma samples. The potential mechanism of action was finally investigated using Gene Set Enrichment Analysis (GSEA) enrichment analysis, Gene Ontology (GO) pathway enrichment analysis, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. The expression of PCK was lower in lung adenocarcinoma tumor tissues than in paracancerous tissues. Patients with lung adenocarcinoma who expressed PCK2 at high levels fared better in overall survival (OS), disease-specific survival (DSS), and progression free interval (PFI). PCK2 was positively correlated with programmed cell death 1 (PDCD1) expression, and its mutation rate in lung adenocarcinoma was 0.53%. CancerSEA research revealed that in lung adenocarcinoma, PCK2 was negatively correlated with epithelial-mesenchymal transition (EMT) and hypoxia. Gene ontology and KEGG enrichment analysis revealed PCK2-coexpressed genes influenced the onset and progression of lung adenocarcinoma by modulating the activity of DNA-binding transcriptional activators, the specificity of RNA polymerase II, the interaction between neuroactive ligands and their receptors, and the cAMP signaling pathway. The prognosis for lung adenocarcinoma was shown to vary according to whether PCK2 was involved in the response to oxidative stress-induced senescence, gene silencing, cell cycle, and other biological processes. An increased expression of PCK2 may be employed as a novel prognostic biomarker in patients with lung adenocarcinoma and has been shown to increase OS, DSS, and PFI. Improving the prognosis of lung adenocarcinoma by interference with PCK2 may be possible since it induces senescence through the oxidative stress response and blocks the immune escape of tumor cells. These results point to a probable target anticancer treatment development in lung adenocarcinoma.

Abstract 5935: Phenotype profiling of tumor microenvironment in EGFR mutant lung adenocarcinoma with multi-omics data

Abstract Introduction: EGFR mutations holds the major targets for drug in lung adenocarcinoma (LUAD). Despite the tremendous study of EGFR mutant (MT) LUAD, the comprehensive interpretation of the heterogeneous character of LUAD harboring EGFR MT remains a key challenge. Here, we investigated the heterogeneity of EGFR MT LUAD and explored the tumor microenvironment (TME) in EGFR MT LUAD. Method: We performed single-cell RNA sequencing (scRNA-seq) from 135 LUAD patients which consist of normal(n=24), EGFR wild (WT)(n=18), and MT(n=93). Also, we used whole genome sequencing and bulk-RNA sequencing to validate with scRNA-seq results. From 898,648 cells, main cell types were classified. To explore the various characteristics of MT LUAD tumor cells, we used two ways: i) We re-clustered epithelial cells populating the normal, WT, and MT. ii) We re-clustered only MT epithelial cells. In each analysis, we identified the tumor character in the clusters using differential expressed genes analysis, lineage tracing, clinical information, mutation, and trajectory analysis. Also, we extracted each main cell type except epithelial cells, and identified subtypes of main cell types. Finally, we revealed the interaction of cellular components in TME. Results: In the analysis of epithelial cells, we identified characteristics of specific EGFR MT by comparing of EGFR WT and MT tumors in clusters with similar biological features. The cluster represented by alveolar type 2 (AT2) known as initiation of LUAD was populating normal, WT, and MT. In this cluster, MT- and WT-associated pathway shared but differently significant between MT and WT in the pathway analysis. The cluster represented by proliferative is mostly comprised tumor cells and we found significantly increased the expression of MDK, CD24 in the MT of the cluster. In the analysis of only MT epithelial cells, 2 of clusters were stage-specific cluster: i) The cluster annotated as early stage cluster, ii) The cluster annotated as advanced stage cluster. Trajectory showed that there is a pseudotemporal continuum, following the stage from early stage cluster to advanced stage cluster. Also, based on the lineage tracing, 2 of clusters revealed lineage-specific clusters: i) The cluster annotated as AT2 was enriched from early stage cells, ii) The cluster annotated as basal cell known as origin of lung squamous cell carcinoma(LUSC) was enriched from advanced stage cells. Psedotemporal ordering of these cluster revealed AT2 cluster transdifferentiate into basal cell cluster which implied the possibility of LUAD to LUSC transition by drug resistance. In the interaction of MT and WT TME, the number of signaling received epithelial cells from myeloid cells, endothelial cells, and fibroblasts as sender increased compared with the interaction of normal. Conclusion: We shed light on the ecosystem of TME according to clinical and biological feature of tumor in EGFR mutant LUAD. Citation Format: You Won Lee, Eun Ji Lee, Seung Yeon Oh, Kyoung-Ho Pyo, Seong Gu Heo, YoungJoon Park, Su-Jin Choi, Kyumin Lim, Ju-hyeon Lee, Jae Hwan Kim, Jii Bum Lee, Ji Yoon Lee, Sun Min Lim, Chang Gon Kim, Min Hee Hong, Mi Ran Yun, Byoung Chul Cho. Phenotype profiling of tumor microenvironment in EGFR mutant lung adenocarcinoma with multi-omics data. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5935.

Expression Analysis of Ligand-Receptor Pairs Identifies Cell-to-Cell Crosstalk between Macrophages and Tumor Cells in Lung Adenocarcinoma.

Background Lung adenocarcinoma is one of the most commonly diagnosed malignancies worldwide. Macrophage plays crucial roles in the tumor microenvironment, but its autocrine network and communications with tumor cell are still unclear. Methods We acquired single-cell RNA sequencing (scRNA-seq) (n = 30) and bulk RNA sequencing (n = 1480) samples of lung adenocarcinoma patients from previous literatures and publicly available databases. Various cell subtypes were identified, including macrophages. Differentially expressed ligand-receptor gene pairs were obtained to explore cell-to-cell communications between macrophages and tumor cells. Furthermore, a machine-learning predictive model based on ligand-receptor interactions was built and validated. Results A total of 159,219 single cells (18,248 tumor cells and 29,520 macrophages) were selected in this study. We identified significantly correlated autocrine ligand-receptor gene pairs in tumor cells and macrophages, respectively. Furthermore, we explored the cell-to-cell communications between macrophages and tumor cells and detected significantly correlated ligand-receptor signaling pairs. We determined that some of the hub gene pairs were associated with patient prognosis and constructed a machine-learning model based on the intercellular interaction network. Conclusion We revealed significant cell-to-cell communications (both autocrine and paracrine network) within macrophages and tumor cells in lung adenocarcinoma. Hub genes with prognostic significance in the network were also identified.

Identification of Novel Multi-Omics Expression Landscapes and Meta-Analysis of Landscape-Based Competitive Endogenous RNA Networks in ALDH+ Lung Adenocarcinoma Stem Cells.

ALDH+ H1975 lung adenocarcinoma stem cells (LSCs) are a rare cell population identified in lung adenocarcinoma (LUAD). LSCs can self-renew, drive tumor initiation, growth, metastasis, and recurrence and are also the predominant cause of poor prognosis due to their intrinsic resistance to drugs and chemotherapy. Consequently, LSCs are a promising target for LUAD therapy. Noncoding RNAs (ncRNAs), including microRNAs (miRNAs), long noncoding RNAs (lncRNAs), and circular RNAs (circRNAs), exert many significant regulatory functions in the pathogenesis of human cancers, showing the necessity for a comprehensive understanding of the mechanisms that underlie lung carcinogenesis. Nonetheless, research on many known transcripts and messenger RNAs (mRNAs) has already generated new information. Unknown biomarkers in ncRNAs and systematic and comprehensive interrelation with unknown ncRNAs and mRNAs may provide further insights into the biology of LUAD. Herein, a set of novel ncRNAs that include miRNAs, lncRNAs, and circRNAs were identified, and differentially expressed patterns of ncRNAs and mRNAs in LSCs and ALDH-H1975 LUAD tumor cells (LTCs) were obtained using stringent bioinformatics pipelines. Through a meta-analysis of the identified landscapes, novel competitive endogenous RNA (ceRNA) networks were constructed to reveal the potential molecular mechanisms that regulate the hallmarks of LSCs and LTCs. This study presents a summary of novel ncRNAs and the fundamental roles of differentially expressed ncRNAs implicated in the activity of LSCs and LTCs. In addition, the study also provides a comprehensive resource for the future identification of diagnostic, therapeutic, and prognostic biomarkers in LUAD.

BCAR1 plays critical roles in the formation and immunoevasion of invasive circulating tumor cells in lung adenocarcinoma.

Background: We investigated the roles of breast cancer anti-estrogen resistance 1 (BCAR1/p130Cas) in the formation and immunoevasion of invasive circulating tumor cells (CTCs) in lung adenocarcinoma (LUAD).Methods: Biomarkers of CTCs including BCAR1 and CD274, were evaluated by the CanPatrol method. Proteomics analysis of LUAD cells and exosomes after BCAR1 overexpression (BCAR1-OE) was performed by mass spectrometry. Cell functions and relevant signaling pathways were investigated after BCAR1 knockdown (BCAR1-KO) or BCAR1-OE in LUAD cells. Lastly, in vitro and in vivo experiments were performed to confirm the roles of BCAR1 in the formation and immunoevasion of CTCs.Results:High expression of BCAR1 by CTCs correlated with CD274 expression and epithelial-to-mesenchymal transition (EMT). RAC1, together with BCAR1, was found to play an important role in the carcinogenesis of LUAD. RAC1 functioned with BCAR1 to induce EMT and to enhance cell proliferation, colony formation, cell invasion and migration, and anoikis resistance in LUAD cells. BCAR1 up-regulated CD274 expression probably by shuttling the short isoform of BRD4 (BRD4-S) into the nucleus. CTCs, as well as tumor formation, were prohibited in nude mice xenografted with BCAR1-KO cells. The co-expression of BCAR1/RAC1 and BCAR1/CD274 was confirmed in LUAD. BCAR1 expression in LUAD is an indicator of poor prognosis, and it associates with immunoevasion.Conclusion:BCAR1, as a new target for the treatment of LUAD, plays roles in the formation and immunoevasion of invasive CTCs. The mechanism includes triggering EMT via RAC1 signaling and up-regulating CD274 expression by shuttling BRD4-S into the nucleus.

Abstract 5752: Protumoral and pro-metastatic effects of TLR7 in lung cancer

Abstract TLR7 agonists are currently under investigations for their ability to enhance anti-tumor immune responses. However, in some tumor models, these agonists also stimulate tumor cells, which can express high levels of TLR7, a receptor for single-stranded RNA [1]. We have demonstrated that stimulation of lung tumor cell lines expressing TLR7 with synthetic TLR7 agonists led to upregulation of the antiapoptotic protein Bcl-2, tumor cell survival and chemoresistance [2]. In Non-Small-Cell Lung Carcinoma (NSCLC) cohorts of patients, we have observed high expression of TLR7 on tumor cells of 70% of patients, which conferred poor clinical outcome and was strongly associated with resistance to chemotherapy [3]. This pro-tumoral effect of TLR7 has been validated in murine models in which the injection of TLR7 agonists in NOD/SCID mice, in C57BL/6 wild-type or in TLR7-deficient mice grafted with lung adenocarcinoma tumor cells led to increased tumor progression, increased lung metastasis, and resistance to chemotherapy. On the contrary, we demonstrated that TLR7 antagonist injection led to antitumoral effect. Additionally, TLR7 stimulation resulted in a significant increase of Myeloid-Derived Suppressor Cells (MDSC) in the tumor microenvironment. Depletion experiments of MDSC indicated that these cells are involved in the pro-tumoral effect induced upon TLR7 stimulation. Finally, we have demonstrated that the pro-tumoral effect of TLR7 stimulation, mediated by the MDSC recruitment, was independent of TLR7 stimulation on immune cells. Our results reveal the mechanism by which TLR7 stimulation induce the pro-tumoral effect in mice, and open the way to the development of novel cancer therapeutics including TLR7 inhibitors, for NSCLC patients. This results demonstrate the important role of TLR7 in lung tumor progression. Knowing that natural ligands of TLR7 are ssRNA, we suppose that this effect could be linked to viral infections or RNA released in the tumor microenvironment. [1] Dajon, et al. Immunobiologie. 2016 [2] Cherfils-Vicini J, et al. J Clin Invest. 2010 [3] Chatterjee J, et al. Cancer Res. 2014 Citation Format: Marion Dajon, Kristina Iribarren, Marco Alifano, Diane Damotte, Isabelle Cremer. Protumoral and pro-metastatic effects of TLR7 in lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5752.

Polymer nanofiber-based microchips for EGFR mutation analysis of circulating tumor cells in lung adenocarcinoma.

BackgroundCirculating tumor cells (CTCs) detection, an approach considered to be “liquid biopsy”, is a potential alternative method in clinical use for early diagnosis of solid tumor progression.MethodsIn this study, we developed a poly (lactic-co-glycolic acid) (PLGA) – nanofiber (PN)-NanoVelcro chip as an efficient device for simple and rapid capture of CTCs from peripheral blood. We evaluated the device performance by assessing the capture efficiency and purity. Single CTC was isolated via laser microdissection system for subsequent genetic analysis, with an aim to find the concordance of epidermal growth factor receptor (EGFR) mutations between tumor tissue and CTCs.ResultsPN-NanoVelcro chip exhibits great performance in capture efficiency and high purity. The genetic analysis results showed that most EGFR mutation in tumor tissue could also be detected in CTCs.ConclusionCompared to computed tomography image results, CTC detection can be implemented throughout the course of diseases and provides an accurate and earlier diagnosis of tumor progression, which make it possible for patients to acquire suitable and timely treatment.

Abstract A124: Protumoral effects of TLR7 in lung tumors

Abstract TLR7 agonists are currently under investigations for their ability to enhance anti-tumor immune responses. However, in some tumor models, these agonists can also stimulate tumor cells, which express high levels of TLR7. In Non-Small-Cell Lung Carcinoma (NSCLC), we have demonstrated that high expression of TLR7 conferred poor clinical outcome and was strongly associated with resistance to chemotherapy. This protumorigenic effect of TLR7 has been validated in murine models in which the injection of TLR7 agonists in NOD/SCID mice, in C57BL/6 wild-type or in TLR7-deficient mice grafted with lung adenocarcinoma tumor cells led to increased tumor progression and chemotherapeutic resistance. TLR7 stimulation resulted in a significant increase of Myeloid-Derived Suppressor Cells (MDSC) in the tumor microenvironment. Depletion experiments of MDSC indicated that these cells appeared to be responsible to the in vivo pro-tumoral effect induced upon TLR7 stimulation. Finally, we have demonstrated that the pro-tumoral effect of TLR7 stimulation, mediated by the MDSC recruitment, was independent of stimulation of TLR7 of immune cells. Our results reveal the mechanism by which TLR7 stimulation induce the pro-tumoral effect in mice, and open the way to the development of novel cancer therapeutics including TLR7 inhibitors, for NSCLC patients. Citation Format: Marion Dajon, Kristina Iribarren, Isabelle Cremer. Protumoral effects of TLR7 in lung tumors [abstract]. In: Proceedings of the Second CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; 2016 Sept 25-28; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(11 Suppl):Abstract nr A124.

High expression levels of MAGE-A9 are correlated with unfavorable survival in lung adenocarcinoma.

A variety of melanoma-associated antigen-A (MAGE-A) protein are commonly detected in lung cancers. Their biological function is not well characterized but may involve cell cycle progression and the regulation of apoptosis. We hypothesized that MAGE-A9 is involved in the regulation of apoptosis. To test this hypothesis, we evaluated MAGE-A9 protein expression by immunohistochemical staining and we assessed the relationship between the expression of MAGE-A9 and clinical pathological parameters. In addition, we investigated the effect of MAGE-A9 down-regulation in lung adenocarcinoma. The results showed that a high expression level of MAGE-A9 protein in lung adenocarcinoma tumor cells was related to larger tumor diameter (P = 0.013) and poor differentiation (P = 0.029). Cox regression analysis revealed that the expression of MAGE-A9 in lung adenocarcinoma tumor cells (P < 0.001) is an independent prognostic factor in five-year survival rates. NSCLC cells with silenced MAGE-A9 had decreased cell proliferation, migration and invasion in cell culture compared to corresponding control cells. The NSCLC cells showing down-regulated MAGE-A9 induced the expression of apoptosis-associated proteins. In addition, MAGE-A9 was associated with resistance to conventional chemotherapeutic agents. Our findings provide evidence that MAGE-A9 could be a potential therapeutic target in NSCLC.

427. 3D Modeling of Lung Adenocarcinoma With a Hydrogel Scaffold

The contribution of the microenvironment to tumorigenesis is now widely recognized and encompasses both the 3D architectural structure and the interaction between malignant and normal stromal cells. This interactivity cannot be reproduced by conventional 2D cell culture systems. We have developed a fibrin-based hydrogel 3D lung cancer model that allows in vitro and in vivo modeling of tumor-stromal interaction under reproducible and tunable conditions. We engineered the model by culturing tumor cells (A549 or H1299), alone or in combination with fibroblasts (MRC5) and/or endothelial cells (HUVECs), within a PEG-fibrin hydrogel which is readily produced, biocompatible and stable (for up to 40 days). The hydrogel 3D culture can be monitored through microscopy and enables cells to acquire a more physiological ‘tumor-like’ morphology compared to 2D cultures. An enzymatic system (Nattokinase) enables efficient cell retrieval of almost 100% of the cells, which are >95% viable and retain their surface markers. Using this model we showed that A549 lung adenocarcinoma tumor cells organized into glandular clusters whose H&E structures and phenotype was modified by the accessory cells present. In the presence of the stromal cells, a more aggressive phenotype developed: more clusters of bigger size were revealed (cluster/10 hpf 6, 4 and 12, with sizes of 0.03-0.2 mm, 0.1-0.3 mm and 0.1-1.0 mm respectively in the A549, A549+MRC5 and A549+MRC5+HUVECs). Ki-67 staining confirmed a higher proliferation in the presence of both MRC5 and HUVECs (MIB1=15%), compared to MRC5 (MIB1=5%) or A549 only (MIB1=0%). We monitored A549 growth using the bioluminescence from transgenic Ff-luciferase and found significantly increased signal (log10) in the presence of MRC5, as early as D3 of culture (8.96±0.03 vs 8.66±0.08 of A549 only; p<0.0001). Having shown the feasibility of 3D-modeling a lung adenocarcinoma, we compared the response of these 3D tumors to the oncolytic adenovirus (OncAd) ICOVIR15 with the effects on 2D culture and compared both with the activity of the OncAd in vivo in a SCID-beige mice xenograft model by monitoring tumor bioluminescence. The 3D model more closely replicated the kinetics of tumor growth control in vivo than did the 2D model. Control required 14 days in vivo and in the3D model whereas in the 2D culture complete eradication was obtained by day 7 (fold increase in signal in untreated and treated groups respectively at day 14: in vivo, 14.56±7.81 and 6.50±5.24 vs 3D, 7.41±4.02 and 2.75±0.72 vs 2D, 328.3±72.71 and 0.01±0.01). To test the system in vivo, we injected the hydrogels (A549, A549 + MRC5 or A549+MRC5+HUVECs) i.p. into SCID-beige mice and let them grow for 2 weeks before retrieving and analyzing them. The tumor grew as islands and H&E confirmed a more aggressive phenotype, with larger tumor size and higher vascularization in the presence of MRC5 and HUVECs. In conclusion, we developed a 3D lung adenocarcinoma model with morphological and biological features of in vivo tumors. This model offers the opportunity to study, in vitro and in vivo, the role of human stroma in cancer progression and to more realistically predict tumor response to biological and other therapies including Onc Ad.

Spiculisporic acid analogues of the marine-derived fungus, Aspergillus candidus strain HDf2, and their antibacterial activity.

Two novel antibiotic spiculisporic acid analogues, named as spiculisporic acid F (1) and G (2), and two known compounds, (-)-spiculisporic acid (3) and secospiculisporic acid B (4), were isolated by bioactivity-guided fractionation from the fermentation broth of the sea urchin-derived Aspergillus candidus strain HDf2. Their structures were unambiguously established by comprehensive analysis of 1D and 2D NMR, and high-resolution MS spectra, and by comparison with known compounds. Biological experiments demonstrated that compounds 1 and 2 displayed antibacterial activity against Gram-negative Pseudomonas solanacearum and Gram-positive Staphylococcus aureus, but showed no cytotoxicity against SGC-7901 human gastric adenocarcinoma and SPC-A-1 human lung adenocarcinoma tumor cell lines. This is the first critical evidence identifying spiculisporic acid derivatives as a potential bio-control agent for the soil borne pathogen P. solanacearum (E. F. Smith) Smith. These findings provide further insight into the chemical and biological activity diversity of this class of compounds.

TLR7 promotes tumor progression, chemotherapy resistance, and poor clinical outcomes in non-small cell lung cancer.

Toll-like receptors (TLR) recognize pathogen molecules and danger-associated signals that stimulate inflammatory processes. TLRs have been studied mainly in antigen-presenting cells, where they exert important immune regulatory functions, but they are also expressed by epithelial tumor cells, where they have been implicated in tumor progression. In this study, we demonstrate that the injection of TLR7 agonist in NOD/SCID mice, in C57BL/6 wild-type, and TLR7-deficient mice grafted with lung adenocarcinoma tumor cells leads to increased tumor progression and chemotherapeutic resistance. In patients with non-small cell lung cancer, expression analyses revealed that high TLR7 expression was strongly associated with resistance to neoadjuvant chemotherapy and poor clinical outcomes. Our findings delineate a crucial role for TLR7 in lung cancer physiopathology. Cancer Res; 74(18); 5008-18. ©2014 AACR.

Newly identified biomarkers for detecting circulating tumor cells in lung adenocarcinoma.

Circulating tumor cells (CTCs) have been implicated in cancer prognosis and follow up. Detection of CTCs was considered significant in cancer evaluation. However, due to the heterogeneity and rareness of CTCs, detecting them with a single maker is usually challenged with low specificity and sensitivity. Previous studies concerning CTCs detection in lung cancer mainly focused on non-small cell lung carcinoma. Currently, there is no report yet describing the CTC detection with multiple markers in lung adenocarcinoma. In this study, by employing quantitative real-time PCR, we identified four candidate genes (mRNA) that were significantly elevated in peripheral blood mononuclear cells and biopsy tissue samples from patients with lung adenocarcinoma: cytokeratin 7 (CK7), Ca(2+)-activated chloride channel-2 (CLCA2), hyaluronan-mediated motility receptor (HMMR), and human telomerase catalytic subunit (hTERT). Then, the four markers were used for CTC detection; namely, positive detection was defined if at least one of the four markers was elevated. The positive CTC detection rate was 74.0% in patients with lung adenocarcinoma while 2.2% for healthy controls, 6.3% for benign lung disease, and 48.0% for non-adenocarcinoma non-small cell lung carcinoma. Furthermore, in a three-year follow-up study, patients with an increase in the detection markers of CTCs (CK7, CLCA2, HMMR or hTERT) on day 90 after first detection had shorter survival time compared to those with a decrease. These results demonstrate that the combination of the four markers with specificity and sensitivity is of great value in lung adenocarcinoma prognosis and follow up.

Antagonism of adenosine A2A receptor expressed by lung adenocarcinoma tumor cells and cancer associated fibroblasts inhibits their growth

Recently it has become clear that the cost associated with the Warburg effect, which is inefficient production of ATP, is offset by selective advantages that are produced by resultant intracellular metabolic alterations. In fact tumors may be addicted to the Warburg effect. In addition these alterations result in changes in the extracellular tumor microenvironment that can also produce selective advantages for tumor cell growth and survival. One such extracellular alteration is increased adenosine concentrations that have been shown to impair T cell mediated rejection and support angiogenesis. The expression of the A2A receptor in non-small cell cancer (NSCLC) tissues, cell lines and cancer associated fibroblasts (CAF) was determined by performing immunohistrochemistry and immunoblot analysis. The efficacy of the A2A receptor antagonists in vivo was evaluated in a PC9 xenograft model. To determine the mode of cell death induced by A2A receptor antagonists flow cytometry, immunoblot, and cytotoxic analysis were performed. We found that a significant number of lung adenocarcinomas express adenosine A2A receptors. Antagonism of these receptors impaired CAF and tumor cell growth in vitro and inhibited human tumor xenograft growth in mice. These observations add to the rationale for testing adenosine A2A receptor antagonists as anticancer therapeutics. Not only could there be prevention of negative signaling in T cells within the tumor microenvironment and inhibition of angiogenesis, but also an inhibitory effect on tumor-promoting, immunosuppressive CAFs and a direct inhibitory effect on the tumor cells themselves.

E2F1 induces apoptosis and sensitizes human lung adenocarcinoma cells to death-receptor-mediated apoptosis through specific downregulation of c-FLIPshort

E2F1 is a transcription factor that plays a well-documented role during S phase progression and apoptosis. We had previously postulated that the low level of E2F1 in primary lung adenocarcinoma contributes to their carcinogenesis. Here, we show that E2F1 triggers apoptosis in various lung adenocarcinoma cell lines by a mechanism involving the specific downregulation of the cellular FLICE-inhibitory protein short, leading to caspase-8 activation at the death-inducing signaling complex. Importantly, we also provide evidence that E2F1 sensitizes tumor as well as primary cells to apoptosis mediated by FAS ligand or tumor necrosis factor-related apoptosis-inducing ligand, and enhances the cytotoxic effect of T lymphocytes against tumor cells. Finally, we describe the specific overexpression of c-FLIP(S) in human lung adenocarcinomas with low level of E2F1. Overall, our data identify E2F1 as a critical determinant of the cellular response to death-receptor-mediated apoptosis, and suggest that its downregulation contributes to the immune escape of lung adenocarcinoma tumor cells.