Lung Cancer Metastasis Model Research Articles

Chitosan nanomedicine containing RGD peptide and PAD4 inhibitor based on phenyl boronate coupling inhibition of primary tumor growth and lung metastasis

Stimulus-responsive nanodrugs have been extensively studied and their structural changes in the cells are important for controlled intracellular drug release. Histone citrullination of peptidylarginine deiminase 4 (PAD4) regulates the expression of tumor suppressor genes. In our previous study, compounds such as YW3–56 (356) were developed as potent PAD4 inhibitors with excellent anti-tumor activity in vitro and in vivo. To enhance the antitumor activity and improve the bioavailability, we further optimized the structure by modifying the phenylboronic acid moiety to the PAD4 inhibitor (4B). Taking advantage of the oxidative stress responsiveness of the phenylboronic acid moiety, in this study, we covalently attached 4B to RGD sequence peptide modified chitosan (K-CRGDV) to construct this new oxidative stress responsive nanodrug (K-CRGDV-4B). The modification of RGD sequence peptide conferred the nanodrug the ability to actively target tumors. The release mechanism was verified by UV-Vis spectroscopy, NMR. The anti-tumor and anti-metastatic properties of K-CRGDV-4B were demonstrated by in vitro cytotoxicity assay and in vivo mouse Lewis lung cancer metastasis model. In addition, K-CRGDV-4B modulates the ratio of immune cells in LLC tumor-bearing mice. Immunosuppressive proteins such as PD1 were inhibited, while IFN-γ and IFN-β, which are stimulators of tumor immune responses, were upregulated. Overall, K-CRGDV-4B is a stimulus-responsive nanodrug that responds to the tumor microenvironment by inhibiting PAD4 activity, blocking the formation of neutrophil extracellular traps (NETs), and improving the tumor immune microenvironment.

YBX1 Enhances Metastasis and Stemness by Transcriptionally Regulating MUC1 in Lung Adenocarcinoma.

Abnormal expression of the transcription factor Y-box-binding protein-1 (YBX1) is associated with the proliferation, migration, aggressiveness, and stem-like properties of various cancers. These characteristics contribute to the tumorigenesis and metastasis of cancer. We found that the expression levels of Mucin-1 (MUC1) and YBX1 were positively correlated in lung adenocarcinoma cells and lung adenocarcinoma tissue. Our retrospective cohort study of 176 lung adenocarcinoma patients after surgery showed that low expression of both YBX1 and MUC1 was an independent predictor of the prognosis and recurrence of lung adenocarcinoma. In lung adenocarcinoma cells, the silencing/overexpression of YBX1 caused a simultaneous change in MUC1, and MUC1 overexpression partially reversed the decreased tumor cell migration, aggressiveness, and stemness caused by YBX1 silencing. Moreover, chromatin immunoprecipitation (ChIP) and dual-luciferase reporter assays proved that MUC1 was the downstream target of YBX1 and that YBX1 bound to the -1480~-1476 position in the promoter region of MUC1 to regulate its transcription. Furthermore, in mouse xenograft models and a lung cancer metastasis model, MUC1, which is downstream of YBX1, partially reversed the decreased number and size of tumors caused by YBX1 silencing. In conclusion, our findings indicated a novel mechanism by which YBX1 promotes the stemness and metastasis of lung adenocarcinoma by targeting MUC1 and provided a combination approach for diagnosis different from traditional single tumor biomarkers to predict patient prognosis and provide clinical treatment targets.

Endothelial Tpl2 regulates vascular barrier function via JNK-mediated degradation of claudin-5 promoting neuroinflammation or tumor metastasis.

Increased vascular permeability and leakage are hallmarks of several pathologies and determine disease progression and severity by facilitating inflammatory/metastatic cell infiltration. Using tissue-specific genetic ablation in endothelial cells, we have investigated invivo the role of Tumor progression locus 2 (Tpl2), a mitogen-activated protein kinase kinase kinase (MAP3K) member with pleiotropic effects in inflammation and cancer. In response to proinflammatory stimuli, endothelial Tpl2 deletion alters tight junction claudin-5 protein expression through inhibition of JNK signaling and lysosomal degradation activation, resulting in reduced vascular permeability and immune cell infiltration. This results in significantly attenuated disease scores in experimental autoimmune encephalomyelitis and fewer tumor nodules in a hematogenic lung cancer metastasis model. Accordingly, pharmacologic inhibition of Tpl2 or small interfering RNA (siRNA)-mediated Tpl2 knockdown recapitulates our findings and reduces lung metastatic tumor invasions. These results establish an endothelial-specific role for Tpl2 and highlight the therapeutic potential of blocking the endothelial-specific Tpl2 pathway in chronic inflammatory and metastatic diseases.

Leflunomide Suppresses the Growth of LKB1-Inactivated Tumors in the Immune-Competent Host and Attenuates Distant Cancer Metastasis.

Liver kinase B1 (LKB1)-inactivated tumors are vulnerable to the disruption of pyrimidine metabolism, and leflunomide emerges as a therapeutic candidate because its active metabolite, A77-1726, inhibits dihydroorotate dehydrogenase, which is essential for de novo pyrimidine biosynthesis. However, it is unclear whether leflunomide inhibits LKB1-inactivated tumors in vivo, and whether its inhibitory effect on the immune system will promote tumor growth. Here, we carried out a comprehensive analysis of leflunomide treatment in various LKB1-inactivated murine xenografts, patient-derived xenografts, and genetically engineered mouse models. We also generated a mouse tumor-derived cancer cell line, WRJ388, that could metastasize to the lung within a month after subcutaneous implantation in all animals. This model was used to assess the ability of leflunomide to control distant metastasis. Leflunomide treatment shrank a HeLa xenograft and attenuated the growth of an H460 xenograft, a patient-derived xenograft, and lung adenocarcinoma in the immune-competent genetically engineered mouse models. Interestingly, leflunomide suppressed tumor growth through at least three different mechanisms. It caused apoptosis in HeLa cells, induced G1 cell-cycle arrest in H460 cells, and promoted S-phase cell-cycle arrest in WRJ388 cells. Finally, leflunomide treatment prevented lung metastasis in 78% of the animals in our novel lung cancer metastasis model. In combination, these results demonstrated that leflunomide utilizes different pathways to suppress the growth of LKB1-inactivated tumors, and it also prevents cancer metastasis at distant sites. Therefore, leflunomide should be evaluated as a therapeutic agent for tumors with LKB1 inactivation.

Efficacy of Paclitaxel Combined with Kanglaite Injection in Treatment of Bone Metastases of Lung Cancer

We aimed to investigate the efficacy of paclitaxel combined with kanglaite injection in the treatment of bone metastases of lung cancer in mice. Human lung cancer cell line A549 was inoculated into 100 C57BL/6 mice to establish bone metastasis model of lung cancer. Eighty successful modeling mice were randomly divided into four groups: Kanglaite (group A), Paclitaxel (group B), Paclitaxel combined with kanglaite (group C) and 0.9% sodium chloride solution (control group), 20 in each group. The mice started taking drugs on the 5th day after inoculation. The treatment lasted for 21 days, and the changes of body weight were observed. Evaluation of the efficacy of drug therapy was performed by comparing the pain behavior of the treated mice with that of the control mice. The physical improvement rates in group A and group B were lower than that in group C (P<0.05). The bone metastasis area and tumor weight in group A, group B and group C were significantly lower than those in control group after 21 days of treatment (P<0.05). The tumor area and tumor weight in group C were significantly lower than those in group A and group B (P<0.05). Paclitaxel combined with kanglaite is more effective than paclitaxel or kanglaite alone in improving bone metastasis of lung cancer and has an important significance in clinical treatment of bone metastasis of lung cancer.

Endothelial Tpl2 Regulates Vascular Barrier Function Via Tight Junction Protein Claudin-5 Promoting CNS Cell Infiltration and Tumor Metastasis

Increased vascular permeability and leakage are hallmarks of several pathologies and determine disease progression and severity by facilitating inflammatory / metastatic cell infiltration. Using tissue-specific genetic ablation in endothelial cells, we have investigated in vivo the role of Tpl2, a MAP3 kinase with pleiotropic effects in inflammation and cancer. In response to pro-inflammatory stimuli, endothelial Tpl2 deletion alters Tight Junction (TJ) claudin-5 protein expression and attenuates the increase in vascular permeability, inflammatory cell infiltration and accumulation of plasma proteins. This results in significantly attenuated disease scores in Experimental Autoimmune Encephalomyelitis and significantly less tumor nodules in a haematogenic lung cancer metastasis model. Accordingly, pharmacologic inhibition of Tpl2 or siRNA-mediated Tpl2 knockdown recapitulates our findings and reduces lung metastatic tumor invasions. These results establish a novel endothelial-specific role for Tpl2 in the regulation of TJ-mediated endothelial permeability and highlight the therapeutic potential of Tpl2 blockade in chronic inflammatory and metastatic diseases.

Epithelial-mesenchymal Transition Phenotypes in Vertebral Metastases of Lung Cancer.

Vertebral metastases of non-small cell lung cancer (NSCLC) are frequently diagnosed in the metastatic setting and are commonly identified in the thoracic vertebrae in patients. Treatment of NSCLC bone metastases, which are often multiple, is palliative, and the median survival times are 3 to 6 months. We have characterized spontaneous vertebral metastases in a brain metastases model of NSCLC and correlated these findings with epithelial-mesenchymal transition (EMT). Brain metastases were established in athymic nude mice following intracardiac injection of brain-seeking adenocarcinoma NSCLC cells. Thirty-nine percent of mice (14/36) developed spontaneous vertebral metastases, spinal cord compression, and hind-limb paralysis. Vertebral metastases consisted of an adenocarcinoma phenotype with neoplastic epithelial cells arranged in cords or acini and a mesenchymal phenotype with spindloid neoplastic cells arranged in bundles and streams. Quantitative and qualitative immunohistochemical and immunofluorescence assays demonstrated an increase in vimentin expression compared to cytokeratin expression in vertebral metastases. A correlation with EMT was supported by an increase in CD44 in vertebral metastases and parenchymal metastases. These data demonstrate a translational lung cancer metastasis model with spontaneous vertebral metastasis. The mesenchymal and epithelial phenotype of these spontaneous metastases coupled with EMT provide a conduit to improve drug delivery and overall patient survival.

Zwitterionic Gadolinium(III)-Complexed Dendrimer-Entrapped Gold Nanoparticles for Enhanced Computed Tomography/Magnetic Resonance Imaging of Lung Cancer Metastasis.

Design of dual mode or multimode contrast agents or nanoplatforms with antifouling properties is crucial for improved cancer diagnosis since the antifouling materials are able to escape the clearance of the reticuloendothelial system with improved pharmacokinetics. Herein, we present the creation of zwitterionic gadolinium(III) (Gd(III))-complexed dendrimer-entrapped gold nanoparticles (Au DEN) for enhanced dual mode computed tomography (CT)/magnetic resonance (MR) imaging of lung cancer metastasis. In the present work, poly(amidoamine) (PAMAM) dendrimers of generation 5 were partially decorated with carboxybetanie acrylamide (CBAA), 2-methacryloyloxyethyl phosphorylcholine (MPC), and 1,3-propane sultone (1,3-PS), respectively at different degrees, then used to entrap Au NPs within their interiors, and finally acetylated to cover their remaining amine termini. Through protein resistance, macrophage cellular uptake, and pharmacokinetics assays, we show that zwitterionic Au DEN modified with 1,3-PS exhibit the best antifouling property with the longest half-decay time (37.07 h) when compared to the CBAA- and MPC-modified Au DEN. Furthermore, with the optimized zwitterion type, we then prepared zwitterionic Gd(III)-loaded Au DEN modified with arginine-glycine-aspartic acid peptide for targeted dual mode CT/MR imaging of a lung cancer metastasis model. We disclose that the designed multifunctional Au DEN having an Au core size of 2.7 nm and a surface potential of 7.6 ± 0.9 mV display a good X-ray attenuation property, relatively high r1 relaxivity (13.17 mM s-1), acceptable cytocompatibility, and targeting specificity to αvβ3 integrin-expressing cancer cells and enable effective dual mode CT/MR imaging of a lung cancer metastasis model in vivo. The developed multifunctional zwitterion-functionalized Au DEN may be potentially adopted as an effective nanoprobe for enhanced dual-modal CT/MR imaging of other cancer types.

Non‑invasive monitoring of cisplatin and erlotinib efficacy against lung cancer in orthotopic SCID mouse models by small animal FDG‑PET/CT and CT.

We established patient‑like models of lung cancer metastasis by orthotopically implanting human non‑small cell lung cancer cell lines into SCID mice. We evaluated the utilities of small‑animal computed tomography (CT) and positron‑emission tomography‑computed tomography (PET/CT) in these models to non‑invasively and repeatedly monitor the anticancer effects of cisplatin and erlotinib. We orthotopically implanted three non‑small cell lung cancer cell lines, A549, FT821 and PC‑9, into SCID mice. These mice were then divided into three groups: Control, cis‑diamminedichloroplatinum(II) (CDDP) (7‑mg/kg CDDP, single administration intraperitoneally), and erlotinib (25mg/kg erlotinib/day, oral administration 5days/week). After treatment initiation, we repeatedly performed PET/CT and CT measurements and assessed anticancer effects based on tumor volumes and FDG uptake. A549 tumors were not affected by CDDP or erlotinib. FT821 tumors were highly responsive to CDDP. PC‑9 tumors, which have an epidermal growth factor receptor mutation, were highly responsive to erlotinib. Histological results and metastatic rates correlated with the anticancer effects shown by CT. In our orthotopic SCID mouse lung cancer models, 18FDG‑PET/CT and CT imaging non‑invasively and repeatedly monitored the efficacies of cisplatin and erlotinib against not only implanted tumors, but also mediastinal lymph node metastases.

Abstract B22: Lymphocytes inhibits the tumor metastasis in 4D cellular lung model by reducing the number of live CTCs in circulation

Abstract Objective: Mouse lung cancer cell lines 393P and 344SQ are derived from KrasLA1/+ p53R172HΔG mice and have different metastatic potential in immunocompetent mice. 393P cells have local primary tumor growth but do not form metastatic lesions while344SQ cells form a primary tumor and metastatic lesions when injected into the subcutaneous space of 129 sv mice. We postulated that the presence of lymphocytes led to differential phenotype for these two cells. In order to test this hypothesis, we used novel cellular 4D ex vivo lung cancer metastasis model created using rat lung where we can determine the impact of lymphocytes on number of circulating tumor cells and formation of metastatic lesions. Methods: We grew GFP tagged 393p or 344SQ mice cells on cellular 4D lung model as control group and for treatment group we added activated lymphocytes on day 0, day 3 and day 5. These activated lymphocytes were obtained by harvesting spleen from mice injected with 393p and 344SQ (1Million) in 129Sv mice. Cellular model with GFP tagged CTCs were counted on day 6 and day 11 by Flow sorting instrument. Primary tumor was removed on day 7 and metastatic lesions were allowed to grow till day 14. Tissues were processed for H&amp;E and Immunohistochemistry and the pathologist determined the amount of tumor cells on the slides. Results: Primary tumor was well formed on cellular lung model by both 393p and 344SQ cells with peribronchiolar distribution. Lung matrix was intact in untreated as well as lymphocyte treated cellular models and tumor histology was more like non-small cell lung cancer. Lymphocyte treatment significantly reduces the presence of CTCs in circulation from 393p growing lung models (35172 vs 10592; p=0.02) while no effect was found on CTCs from 344SQ growing models (13841 vs 7072; p=0.27). Furthermore, there were significantly less metastatic lesions formed with 393p growing cellular model in the presence of lymphocytes (p=0.008), while there was no impact of lymphocytes on formation of metastatic lesion with 344SQ. Conclusion: Lymphocytes inhibit metastatic lesion formation in 393P cell lines but not 344SQ cell lines in cellular lung model. The cellular 4D lung recapitulates the phenomenon exhibited by in vivo in presence of activated lymphocytes. The model can be used to study the role of different components of a tumor’s microenvironment in tumor metastasis. Citation Format: Dhruva Kumar Mishra, Ross A. Miller, Min P. Kim. Lymphocytes inhibits the tumor metastasis in 4D cellular lung model by reducing the number of live CTCs in circulation [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2017 Oct 1-4; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2018;6(9 Suppl):Abstract nr B22.

Titanium dioxide nanoparticle stimulating pro-inflammatory responses in vitro and in vivo for inhibited cancer metastasis

The interaction of engineered nanoparticles (NPs) with the immune system and the possibility of inflammation induction are of particularly interest. Titanium dioxide nanoparticles (TiO2 NPs) are one of the most popular manufactured nanomaterials. In this study, we focused on the immune-modulatory effect of commercial P-25 TiO2 NPs in vivo and in vitro and their crucial role in cancer metastasis. The female C57BL/6 mice were injected into abdominal cavity with PBS or P-25 TiO2 to investigate the immune-modulatory function of P-25. And breast cancer cells were intravenously (i.v.) injected into mouse to establish the liver and lung cancer metastasis model. Peritoneal macrophage was used to investigate the macrophage polarization in vitro. Results showed us that peritoneal macrophage exposed to P-25 TiO2 NPs displayed activated M1 macrophage response, as evidenced by the increased mRNA expression of interleukin-1β (IL1β), IL6, TNFα, CCR7 and inducible nitric oxide synthase (iNOS). After exposure of TiO2 NPs in vivo for 21 days, the body weights of mice decreased significantly, which were accompanied by an infiltration of immune cells in liver and spleen in 20 mg/kg BW treated group. Importantly, the production of pro-inflammatory cytokines in liver, spleen and the serum were amplified, which indicated the tissue and systemic inflammation induced by TiO2 NPs. In addition, the activation of immune response induced by P-25 TiO2 NPs was correlated with their ability to inhibit cancer metastasis. Our results delineated the stimulating pro-inflammatory response induced by P-25 TiO2 NPs and their outcome in vivo for cancer metastasis.

CCL19-producing fibroblastic stromal cells restrain lung carcinoma growth by promoting local antitumor T-cell responses

A particular characteristic of non-small cell lung cancer is the composition of the tumor microenvironment with a very high proportion of fibroblastic stromal cells (FSCs). Lapses in our basic knowledge of fibroblast phenotype and function in the tumor microenvironment make it difficult to define whether FSC subsets exist that exhibit either tumor-promoting or tumor-suppressive properties. We used gene expression profiling of lung versus tumor FSCs from patients with non-small cell lung cancer. Moreover, CCL19-expressing FSCs were studied in transgenic mouse models by using a lung cancer metastasis model. CCL19 mRNA expression in human tumor FSCs correlates with immune cell infiltration and intratumoral accumulation of CD8+ T cells. Mechanistic dissection in murine lung carcinoma models revealed that CCL19-expressing FSCsform perivascular niches to promote accumulation of CD8+ T cells in the tumor. Targeted ablation of CCL19-expressing tumor FSCs reduced immune cell recruitment and resulted in unleashed tumor growth. These data suggest that a distinct population of CCL19-producing FSCs fosters the development of an immune-stimulating intratumoral niche for immune cells to control cancer growth.

Inactivation of Capicua drives cancer metastasis.

Metastasis is the leading cause of death in lung cancer patients, yet the molecular effectors underlying tumor dissemination remain poorly defined. Through development of an in vivo spontaneous lung cancer metastasis model, we show that the developmentally-regulated transcriptional repressor Capicua (CIC) suppresses invasion and metastasis. CIC inactivation relieves repression of its effector ETV4, driving ETV4-mediated upregulation of MMP24 that is necessary and sufficient for metastasis. Loss of CIC, or increased levels of its effectors ETV4 and MMP24, is a biomarker of tumor progression and worse outcomes in lung and gastric cancer patients. Our findings uncover CIC as a conserved metastasis suppressor, revealing new anti-metastatic strategies to improve patient outcomes.

Abstract B40: Lineage selective extracellular matrix interactions required for metastatic lung cancer

Abstract Background: Lung cancers are biological heterogeneous malignancies with poor prognosis. The underlying mechanisms of this heterogeneity and their biological consequences for metastasis are poorly understood. We previously examined the molecular relationship between epithelial differentiation states, airway regeneration, lung cancer subtypes, and clinical outcome. By integrating genomics, bioinformatic, and experimental models of lung cancer metastasis, we identified a subset of metastatic lung adenocarcinoma (LUAD) defined by its expression of a novel cell lineage gene expression program (Cheung et al., Cancer Cell 2013). Results: Here we further define the molecular characteristics of this aggressive LUAD subgroup and find that it is driven by epigenetic silencing of know tumor suppressive non-coding RNAs, including mir-34a-c. This in turn activates genes encoding for specific extracellular matrix (ECM) interacting proteins. These ECM proteins include proteoglycans abundant in the inflammatory stroma of human lung cancers and lung tissue from patients with pulmonary fibrosis. Over-expressions of these proteoglycans and their corresponding cell surface receptors are defining features of recognized LUAD histotypes. In an experimental mouse model, genetic perturbations of these ECM/cell surface interactions inhibits the metastasis re-initiating capacity of LUAD cells to distant organs such as the brain. Significantly, these ECM-tumor cell interactions may also be disrupted using targeted agents currently in clinical trials. Conclusions: Our data provide a mechanistic link between the effectors of airway homeostasis, pulmonary fibrosis, and metastasis initiation by specific lung cancers. Consequently, we provide rational strategies to re-position current therapies to target the tumor microenvironment of metastatic lung adenocarcinomas. Citation Format: Don X. Nguyen. Lineage selective extracellular matrix interactions required for metastatic lung cancer. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Metastasis; 2015 Nov 30-Dec 3; Austin, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(7 Suppl):Abstract nr B40.

Targeted Cancer Therapeutics: Biosynthetic and Energetic Pathways Characterized by Metabolomics and the Interplay with Key Cancer Regulatory Factors

Reprogramming of energy metabolism has recently been added to the list of hallmarks that define cancer. Cellular metabolism plays a central role in cancer initiation and progression to metastatic disease. Genotypic and phenotypic metabolic alterations are seen throughout tumourigenesis, allowing cancer cells to sustain increased rates of proliferation. Furthermore, this shift fuels necessary substrates for nucleotide, protein, and lipid synthesis to support cell growth. Beyond the 'Warburg effect', the widely observed increase in the glycolytic processing of glucose in cancer cells, numerous other metabolic changes have been characterized in cancer. Metabolomics provides a valuable platform for the investigation of the metabolic perturbations that occur in different disease states using a systems biology approach to determine metabolic profiles of biological samples. As cell metabolism is a complex network of interdependent pathways, local alterations will have an impact on overall tumor metabolism. In this review, we will highlight particular pathways, including glycolysis, nucleotide biosynthesis, lipid metabolism, and bioenergetics with an eye towards selected metabolic targets that may provide a novel approach to therapeutic development. Specific regulatory factors, including Myc, p53, HIF-1 and mTOR are briefly highlighted, as well as the key signaling pathways that can affect cellular metabolism. To demonstrate the powerful utility of high-throughput metabolite profiling techniques, we present a practical example of the metabolomic profiling of metastatic cells derived from a lung cancer metastasis model.

BRMS1 Suppresses Lung Cancer Metastases through an E3 Ligase Function on Histone Acetyltransferase p300

The mechanisms through which the metastasis suppressor gene BRMS1 functions are poorly understood. Herein, we report the identification of a previously undescribed E3 ligase function of BRMS1 on the histone acetyltransferase p300. BRMS1 induces polyubiquitination of p300, resulting in its proteasome-mediated degradation. We identify BRMS1 as the first eukaryote structural mimic of the bacterial IpaH E3 ligase family and establish that the evolutionarily conserved CXD motif located in BRMS1 is responsible for its E3 ligase function. Mutation of this E3 ligase motif not only abolishes BRMS1-induced p300 polyubiquitination and degradation, but importantly, dramatically reduces the metastasis suppressor function of BRMS1 in both in vitro and in vivo models of lung cancer metastasis.

Hyaluronan synthesis inhibitor supplements the inhibitory effects of zoledronic acid on bone metastasis of lung cancer

Hyaluronan is known to have pivotal roles in the growth, migration and invasion of malignant tumors. Bone metastases are critical lesions greatly impairing the quality of patients with malignancies. We investigated whether hyaluronan synthesis inhibitor supplements the inhibitory effects of zoledronic acid, which is a conventional therapeutic agent for bone metastasis. We examined the effects of methylumbelliferone, an inhibitor of hyaluronan synthesis and/or ZA on the tumorigenicity of one murine lung carcinoma and two human (A549, SK-MES-1) lung cancer cell lines in vitro. The interaction between methylumbelliferone and zoledronic acid was analyzed using Calcucyn software. With a murine bone metastasis model of lung cancer in vivo, we investigated the inhibitory effects and interaction of the two drugs on the progression of metastatic bone lesions. Methylumbelliferone or zoledronic acid treatment individually suppressed proliferation, migration and invasion of 3 cell lines, and combination treatment showed synergistic effects. Although methylumbelliferone as a single agent did not enhance apoptotic activity, it showed additive effects on apoptotic activity to those of zoledronic acid. Co-localization of CD44 and ezrin, which might be a pathway of hyaluronan signaling, was abrogated by methylumbelliferone treatment. Combination therapy showed additive inhibitory effects on metastatic bone lesions in vivo, which paralleled the inhibition of hyaluronan accumulation by methylumbelliferone, and inhibition of osteoclastogenesis. Although the detailed mechanisms underlying the synergistic or additive inhibitory effects of these two drugs should be further analyzed, inhibition of hyaluronan synthesis by methylumbelliferone is a promising novel therapeutic candidate for bone metastasis of lung cancer in addition to zoledronic acid.

Array-Based Sensing of Metastatic Cells and Tissues Using Nanoparticle–Fluorescent Protein Conjugates

Rapid and sensitive methods of discriminating between healthy tissue and metastases are critical for predicting disease course and designing therapeutic strategies. We report here the use of an array of gold nanoparticle-green fluorescent protein elements to rapidly detect metastatic cancer cells (in minutes), as well as to discriminate between organ-specific metastases and their corresponding normal tissues through their overall intracellular proteome signatures. Metastases established in a new preclinical non-small-cell lung cancer metastasis model in athymic mice were used to provide a challenging and realistic testbed for clinical cancer diagnosis. Full differentiation between the analyte cell/tissue was achieved with as little as 200 ng of intracellular protein (~1000 cells) for each nanoparticle, indicating high sensitivity of this sensor array. Notably, the sensor created a distinct fingerprint pattern for the normal and metastatic tumor tissues. Moreover, this array-based approach is unbiased, precluding the requirement of a priori knowledge of the disease biomarkers. Taken together, these studies demonstrate the utility of this sensor for creating fingerprints of cells and tissues in different states and present a generalizable platform for rapid screening amenable to microbiopsy samples.

Receptor of Activated Protein C Promotes Metastasis and Correlates with Clinical Outcome in Lung Adenocarcinoma

Efficient metastasis requires survival and adaptation of tumor cells to stringent conditions imposed by the extracellular milieu. Identification of critical survival signaling pathways in tumor cells might unveil novel targets relevant in disease progression. To investigate the contribution of activated protein C (APC) and its receptor (endothelial protein C receptor [EPCR]) in animal models of lung cancer metastasis and in patients with lung adenocarcinoma. Signaling pathway triggered by APC/EPCR and its relevance in apoptosis was studied in vitro. Functional significance was assessed by silencing and blocking antibodies in several in vivo models of lung cancer metastasis in athymic nude Foxn1(nu) mice. We examined EPCR levels using a microarray dataset of 107 patients. Immunohistochemical analysis was performed in an independent cohort of 295 patients with lung adenocarcinoma. The effects of APC binding to EPCR rapidly triggered Akt and extracellular signal-regulated kinase signaling pathways, leading to attenuated in vitro apoptosis. In vivo, silencing of EPCR expression or blocking APC/EPCR interaction reduced infiltration in the target organ, resulting in impaired prometastatic activity. Moreover, overexpression of EPCR induced an increased metastatic activity to target organs. Analysis of clinical samples showed a robust association between high EPCR levels and poor prognosis, particularly in stage I patients. EPCR and its ligand APC promote cell survival that contributes to tumor cell endurance to stress favoring prometastatic activity of lung adenocarcinoma. EPCR/APC is a novel target of relevance in the clinical outcome of early-stage lung cancer.

Activation of PPARγ in Myeloid Cells Promotes Lung Cancer Progression and Metastasis

Activation of peroxisome proliferator-activated receptor-γ (PPARγ) inhibits growth of cancer cells including non-small cell lung cancer (NSCLC). Clinically, use of thiazolidinediones, which are pharmacological activators of PPARγ is associated with a lower risk of developing lung cancer. However, the role of this pathway in lung cancer metastasis has not been examined well. The systemic effect of pioglitazone was examined in two models of lung cancer metastasis in immune-competent mice. In an orthotopic model, murine lung cancer cells implanted into the lungs of syngeneic mice metastasized to the liver and brain. As a second model, cancer cells injected subcutaneously metastasized to the lung. In both models systemic administration of pioglitazone increased the rate of metastasis. Examination of tissues from the orthotopic model demonstrated increased numbers of arginase I-positive macrophages in tumors from pioglitazone-treated animals. In co-culture experiments of cancer cells with bone marrow-derived macrophages, pioglitazone promoted arginase I expression in macrophages and this was dependent on the expression of PPARγ in the macrophages. To assess the contribution of PPARγ in macrophages to cancer progression, experiments were performed in bone marrow-transplanted animals receiving bone marrow from Lys-M-Cre+/PPARγflox/flox mice, in which PPARγ is deleted specifically in myeloid cells (PPARγ-Macneg), or control PPARγflox/flox mice. In both models, mice receiving PPARγ-Macneg bone marrow had a marked decrease in secondary tumors which was not significantly altered by treatment with pioglitazone. This was associated with decreased numbers of arginase I-positive cells in the lung. These data support a model in which activation of PPARγ may have opposing effects on tumor progression, with anti-tumorigenic effects on cancer cells, but pro-tumorigenic effects on cells of the microenvironment, specifically myeloid cells.