Mouse Lung Tumor Model Research Articles

Targeted inhibition of GRP78 by HA15 promotes apoptosis of lung cancer cells accompanied by ER stress and autophagy.

ABSTRACTThis study investigated the pathophysiological role of GRP78 in the survival of lung cancer cells. Lung cancer patient data from public databases were used to analyze the expression of GRP78 and its influence on prognoses. In vivo, GRP78 protein expression was analyzed in an established urethane-induced lung tumor mouse model. In vitro, the effects of targeted inhibition of GRP78 by HA15 in lung cancer cells were assessed, with cell viability analyzed using a CCK-8 assay, cell proliferation using an EdU assay, apoptosis and cell cycle using flow cytometry, subcellular structure using electron microscopy, and relative mRNA and protein expression using RT-PCR, western blotting or immunofluorescence assays. The results showed that GRP78 was highly expressed in the lung tissue of lung cancer mice model or patients, and was associated with a poor prognosis. After inhibition of GRP78 in lung cancer cells by HA15, cell viability was decreased in a dose- and time-dependent manner, proliferation was suppressed and apoptosis promoted. Unfolded protein response signaling pathway proteins were activated, and the autophagy-related proteins and mRNAs were upregulated. Therefore, targeted inhibition of GRP78 by HA15 promotes apoptosis of lung cancer cells accompanied by ER stress and autophagy.

IL15-Based Trifunctional Antibody-Fusion Proteins with Costimulatory TNF-Superfamily Ligands in the Single-Chain Format for Cancer Immunotherapy.

IL15 and costimulatory receptors of the tumor necrosis superfamily (TNFRSF) have shown great potential to support and drive an antitumor immune response. However, their efficacy as monotherapy is limited. Here, we present the development of a novel format for a trifunctional antibody-fusion protein that combines and focuses the activity of IL15/TNFSF-ligand in a targeting-mediated manner to the tumor site. The previously reported format consisted of a tumor-directed antibody (scFv), IL15 linked to an IL15Rα-fragment (RD), and the extracellular domain of 4-1BBL, where noncovalent trimerization of 4-1BBL into its functional unit led to a homotrimeric molecule with 3 antibody and 3 IL15-RD units. To reduce the size and complexity of the molecule, we have now designed a second format, where 4-1BBL is introduced as single-chain (sc), that is 3 consecutively linked 4-1BBL ectodomains. Thus, a monomeric trifunctional fusion protein presenting only 1 functional unit of each component was generated. Interestingly, the in vitro activity on T-cell stimulation was conserved or even enhanced for the soluble and target-bound molecule, respectively. Also, in a lung tumor mouse model, comparable antitumor effects were observed. Furthermore, corroborating the concept, OX40L and GITRL were also successfully incorporated into the novel single-chain format and the advantage of target-bound trifunctional versus corresponding combined bifunctional fusion proteins demonstrated by measuring T-cell proliferation and cytotoxic potential in vitro and antitumor effects of RD_IL15_scFv_scGITRL in a lung tumor mouse model in vivo Thus, the trifunctional antibody-fusion protein single-chain format constitutes a promising innovative platform for further therapeutic developments.

Abstract 2048: Stat3 downstream transthyretin stimulates tumor growth through regulation of tumor, immune and endothelial cells

Abstract Lung cancer is a very aggressive malignant form of cancer, and is one of the biggest public health challenges facing the United States and many other countries. Although incidence rates have been stabilized, an estimated 154,050 Americans are expected to die from lung & bronchus cancer in 2018, accounting for approximately 25.3 percent of all cancer deaths. Lung cancer is a difficult disease to detect in its early stages, with greater than 50% of patients diagnosed with lung cancer presenting with metastatic disease. Early detection of lung cancer is an important opportunity for decreasing mortality while it is still treatable and curable. The overall 5-year survival rate is ~15 percent. Thus, it is essential to better understand the mechanisms that initiate lung carcinogenesis and find easy-use biomarkers for more accurate lung cancer detection. Due to heterogeneity of lung cancers, a panel of biomarkers should be used for more accurate lung cancer detection and classification. Signal transducer and activator of transcription 3 (Stat3) is well known for its lung cancer-promoting activity. To assess the consequences of STAT3 persistent activation in the lung, a doxycycline-controlled CCSP-rtTA/(tetO)7-Stat3C bitransgenic mouse model was generated that over-expresses STAT3C (a constitutively active form of STAT3) in alveolar type II (AT II) epithelial cells. In sequential steps, Stat3C over-expression up-regulated pro-inflammatory molecules, increased inflammatory cell infiltration and caused adenocarcinomas in the lung. Using this lung tumor model, thirteen secretory proteins that are Stat3 downstream gene products were identified as a panel of biomarkers for lung cancer detection in human sera. This panel of biomarkers potentially differentiates different types of lung cancer for classification. Among them, the transthyretin (TTR) concentration was highly increased in human serum of lung cancer patients. TTR concentration was also induced in the serum, bronchoalveolar lavage fluid, alveolar type II epithelial cells and alveolar myeloid cells of the CCSP-rtTA/(tetO)7-Stat3C lung tumor mouse model. Recombinant TTR stimulated lung tumor cell proliferation and growth, which were mediated by activation of mitogenic and oncogenic molecules. TTR possesses cytokine functions to stimulate myeloid cell differentiation, which are known to play roles in tumor environment. TTR demonstrated a great influence on a wide spectrum of endothelial cell functions to control tumor and immune cell migration and infiltration. TTR-treated endothelial cells suppressed T cell proliferation. Taken together, Stat3 downstream inducible secretory protein biomarkers potentially can be used as clinical targets for lung cancer personalized treatment if their expression levels are increased in a given lung cancer patient in the blood. Citation Format: Xinchun Ding. Stat3 downstream transthyretin stimulates tumor growth through regulation of tumor, immune and endothelial cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2048.

Transthyretin Stimulates Tumor Growth through Regulation of Tumor, Immune, and Endothelial Cells.

Early detection of lung cancer offers an important opportunity to decrease mortality while it is still treatable and curable. Thirteen secretory proteins that are Stat3 downstream gene products were identified as a panel of biomarkers for lung cancer detection in human sera. This panel of biomarkers potentially differentiates different types of lung cancer for classification. Among them, the transthyretin (TTR) concentration was highly increased in human serum of lung cancer patients. TTR concentration was also induced in the serum, bronchoalveolar lavage fluid, alveolar type II epithelial cells, and alveolar myeloid cells of the CCSP-rtTA/(tetO)7-Stat3C lung tumor mouse model. Recombinant TTR stimulated lung tumor cell proliferation and growth, which were mediated by activation of mitogenic and oncogenic molecules. TTR possesses cytokine functions to stimulate myeloid cell differentiation, which are known to play roles in tumor environment. Further analyses showed that TTR treatment enhanced the reactive oxygen species production in myeloid cells and enabled them to become functional myeloid-derived suppressive cells. TTR demonstrated a great influence on a wide spectrum of endothelial cell functions to control tumor and immune cell migration and infiltration. TTR-treated endothelial cells suppressed T cell proliferation. Taken together, these 13 Stat3 downstream inducible secretory protein biomarkers potentially can be used for lung cancer diagnosis, classification, and as clinical targets for lung cancer personalized treatment if their expression levels are increased in a given lung cancer patient in the blood.

Human Biofield Therapy and the Growth of Mouse Lung Carcinoma.

Biofield therapies have gained popularity and are being explored as possible treatments for cancer. In some cases, devices have been developed that mimic the electromagnetic fields that are emitted from people delivering biofield therapies. However, there is limited research examining if humans could potentially inhibit the proliferation of cancer cells and suppress tumor growth through modification of inflammation and the immune system. We found that human NSCLC A549 lung cancer cells exposed to Sean L. Harribance, a purported healer, showed reduced viability and downregulation of pAkt. We further observed that the experimental exposure slowed growth of mouse Lewis lung carcinoma evidenced by significantly smaller tumor volume in the experimental mice (274.3 ± 188.9 mm3) than that of control mice (740.5 ± 460.2 mm3; P < .05). Exposure to the experimental condition markedly reduced tumoral expression of pS6, a cytosolic marker of cell proliferation, by 45% compared with that of the control group. Results of reversed phase proteomic array suggested that the experimental exposure downregulated the PD-L1 expression in the tumor tissues. Similarly, the serum levels of cytokines, especially MCP-1, were significantly reduced in the experimental group (P < .05). Furthermore, TILs profiling showed that CD8+/CD4− immune cell population was increased by almost 2-fold in the experimental condition whereas the number of intratumoral CD25+/CD4+ (T-reg cells) and CD68+ macrophages were 84% and 33%, respectively, lower than that of the control group. Together, these findings suggest that exposure to purported biofields from a human is capable of suppressing tumor growth, which might be in part mediated through modification of the tumor microenvironment, immune function, and anti-inflammatory activity in our mouse lung tumor model.

Lung cancer search and destroy

Cancer Like many cancer types, lung cancer is easier to treat when it is detected in its early stages. Scafoglio et al. discovered that a glucose transporter called sodium-dependent glucose transporter 2 is specifically found in early-stage lung tumors. They used a receptor-specific, radiolabeled tracer to perform positron emission tomography to identify early tumors. Furthermore, a class of diabetes drugs called gliflozins, which target the same receptor, effectively targeted these lung tumors in mouse models. Sci. Transl. Med. 10 , eaat5933 (2018).

Highlights from Recent Cancer Literature

Highlights from Recent Cancer Literature

Muc1 knockout potentiates murine lung carcinogenesis involving an epiregulin-mediated EGFR activation feedback loop.

Mucin 1 (MUC1) is a tumor antigen that is aberrantly overexpressed in various cancers, including lung cancer. Our previous in vitro studies showed that MUC1 facilitates carcinogen-induced EGFR activation and transformation in human lung bronchial epithelial cells (HBECs), which along with other reports suggests an oncogenic property for MUC1 in lung cancer. However, direct evidence for the role of MUC1 in lung carcinogenesis is lacking. In this study, we used the 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)-induced A/J mouse lung tumor model to investigate the effect of whole-body Muc1 knockout (KO) on carcinogen-induced lung carcinogenesis. Surprisingly, lung tumor multiplicity was significantly increased in Muc1 KO compared to wild-type (WT) mice. The EGFR/AKT pathway was unexpectedly activated, and expression of the EGFR ligand epiregulin (EREG) was increased in the lung tissues of the Muc1 KO compared to the WT mice. EREG stimulated proliferation and protected against cigarette smoke extract (CSE)-induced cytotoxicity in in vitro cultured human bronchial epithelial cells. Additionally, we determined that MUC1 was expressed in human fibroblast cell lines where it suppressed CSE-induced EREG production. Further, suppression of MUC1 cellular activity with GO-201 enhanced EREG production in lung cancer cells, which in turn protected cancer cells from GO-201-induced cell death. Moreover, an inverse association between MUC1 and EREG was detected in human lung cancer, and EREG expression was inversely associated with patient survival. Together, these results support a promiscuous role of MUC1 in lung cancer development that may be related to cell-type specific functions of MUC1 in the tumor microenvironment, and MUC1 deficiency in fibroblasts and malignant cells results in increased EREG production that activates the EGFR pathway for lung carcinogenesis.

Noninvasive Bioluminescence Imaging of AKT Kinase Activity in Subcutaneous and Orthotopic NSCLC Xenografts: Correlation of AKT Activity with Tumor Growth Kinetics

Aberrant signaling through the AKT kinase mediates oncogenic phenotypes including cell proliferation, survival, and therapeutic resistance. Here, we utilize a bioluminescence reporter for AKT kinase activity (BAR) to noninvasively assess the therapeutic efficacy of the EGFR inhibitor erlotinib in KRAS-mutated lung cancer therapy. A549 non–small cell lung cancer cell line, engineered to express BAR, enabled the evaluation of compounds targeting the EGFR/PI3K/AKT pathway in vitro as well as in mouse models. We found that erlotinib treatment of resistant A549 subcutaneous and orthotopic xenografts resulted in significant AKT inhibition as determined by an 8- to 13-fold (P < .0001) increase in reporter activity 3 hours after erlotinib (100 mg/kg) administration compared to the control. This was confirmed by a 25% (P < .0001) decrease in pAKT ex vivo and a decrease in tumor growth. Treatment of the orthotopic xenograft with varying doses of erlotinib (25, 50, and 100 mg/kg) revealed a dose- and time-dependent increase in reporter activity (10-, 12-, and 23-fold). Correspondingly, a decrease in phospho-AKT levels (0%, 16%, and 28%, respectively) and a decrease in the AKT dependent proliferation marker PCNA (0%, 50%, and 50%) were observed. We applied μ-CT imaging for noninvasive longitudinal quantification of lung tumor load which revealed a corresponding decrease in tumor growth in a dose-dependent manner. These findings demonstrate the utility of BAR to noninvasively monitor AKT activity in preclinical studies in response to AKT modulating agents. These results also demonstrate that BAR can be applied to study drug dosing, drug combinations, and treatment efficacy in orthotopic mouse lung tumor models.

SiRNA-Encapsulated Hybrid Nanoparticles Target Mutant K-ras and Inhibit Metastatic Tumor Burden in a Mouse Model of Lung Cancer.

There is an unmet need in the development of an effective therapy for mutant K-ras-expressing non-small-cell lung cancer (NSCLC). Although various small molecules have been evaluated, an effective therapy remains a dream. siRNAs have the potential to downregulate mutant K-ras both at the protein and mRNA levels. However, a safe and effective delivery of siRNAs to tumors remains a limitation to their translational application in the treatment of this highly debilitating disease. Here we developed a novel hybrid nanoparticle carrier for effective delivery of anti-mutant K-ras to NSCLC (AKSLHN). The ability of this treatment modality to regress lung tumors in mouse models was evaluated as a monotherapy or as a combination treatment with erlotinib. Further, the toxicity of this treatment modality to healthy tissues was evaluated, along with its ability to elicit immune/inflammatory reactions. The results suggest that this treatment modality is a promising prospect for the treatment of mutant K-ras-expressing NSCLC without any accompanying toxicity. However, further understanding of the cellular-level interaction between AHSLHN and erlotinib needs to be attained before this promising treatment modality can be brought to the bedside.

Efficacy of a Cancer Vaccine against ALK-Rearranged Lung Tumors.

Non-small cell lung cancer (NSCLC) harboring chromosomal rearrangements of the anaplastic lymphoma kinase (ALK) gene is treated with ALK tyrosine kinase inhibitors (TKI), but the treatment is successful for only a limited amount of time; most patients experience a relapse due to the development of drug resistance. Here, we show that a vaccine against ALK induced a strong and specific immune response that both prophylactically and therapeutically impaired the growth of ALK-positive lung tumors in mouse models. The ALK vaccine was efficacious also in combination with ALK TKI treatment and significantly delayed tumor relapses after TKI suspension. We found that lung tumors containing ALK rearrangements induced an immunosuppressive microenvironment, regulating the expression of PD-L1 on the surface of lung tumor cells. High PD-L1 expression reduced ALK vaccine efficacy, which could be restored by administration of anti-PD-1 immunotherapy. Thus, combinations of ALK vaccine with TKIs and immune checkpoint blockade therapies might represent a powerful strategy for the treatment of ALK-driven NSCLC.

Demethoxycurcumin-Carrying Chitosan–Antibody Core–Shell Nanoparticles with Multitherapeutic Efficacy toward Malignant A549 Lung Tumor: From in Vitro Characterization to in Vivo Evaluation

Targeting controlled release core-shell nanocarriers with the potential to overcome multidrug resistant (MDR) lung cancer were prepared based on demethoxycurcumin (DMC) loaded amphiphilic chitosan nanoparticles coated with an anti-EGFR antibody layer. The nanocarriers were characterized with regard to size with dynamic light scattering, SEM, and TEM. The characterization confirmed the nanocarriers to have a surface coating of the anti-EGFR antibody and a final size excellently suited for circulating targeting nanocarriers, i.e., <200 nm in diameter. In vitro drug release revealed extended quasi-Fickian release from the nanocarriers, with the anti-EGFR layer further reducing the release rate. Cell culture experiments using normoxic and MDR hypoxic cells overexpressing EGFR confirmed improved DMC delivery for anti-EGFR coated particles and revealed that the DMC was delivered to the cytoplasmic region of the cells, forming nanoprecipitates in lysosomes and endosomes. The effective endocytosis and targeting of the core-shell nanoparticles resulted in the nanocarriers achieving high cytotoxicity also against MDR cells. The therapeutic potential was further confirmed in an A549 xenograft lung tumor mouse model, where DMC loaded core-shell nanocarriers achieved about 8-fold reduction in tumor volume compared with control group over the 8 weeks of the investigation. Both in vitro and in vivo data suggest the anti-EGFR coated core-shell nanocarriers as highly promising for treatment of hypoxic MDR cancers, especially for non-small cell lung cancer.

Abstract 89: Development of preclinical lung adenocarcinoma model

Abstract Lung cancer is a leading cause of cancer death in worldwide. 85% of lung cancers are classified as non-small cell lung cancers (NSCLC), and adenocarcinoma (ADC) type is the most prevalent cancer in NSCLC. Approximately 50% of non-small cell lung cancer (NSCLC) patients have mutations in some oncogenes. The K-ras activation due to the mutant is notorious in many kinds of cancer types, including pancreatic cancer and lung adenocarcinoma, as is generally accepted as driving mutation for lung malignancy of lung adenocarcinoma. Another predominantly alternated gene in lung cancer is the EGFR that would hit the similar signaling with K-ras activation, to which small molecules and antibodies target to halt the tumor progression. The tumor suppressor p53 is also often altered in almost all kinds of cancers and lung cancer. In this reason, K-ras activated mouse is utilized as lung cancer mouse model. K-ras activated mouse eventually develops lung adenocarcinoma, which can be accelerated with mutated p53. Due to the gain-of-function, mutant p53 protein contributes to tumor metastasis and shortening the latency of tumor progression. Thereby activated K-ras/mutant p53 mouse is preferentially used as lung adenocarcinoma preclinical model. Here, we have used mouse tumor cells derived from activated K-ras/mutant p53 mouse to establish syngeneic lung cancer mouse model, allowing in vivo imaging. We asked whether the gain-of-function metastatic phenotype observed in the mouse is responsible for the formation of lung tumors when inoculated intravenously. Tumor cells from the mice could efficiently develop tumors in four weeks at the same genetic background. Tumors from the mice were histologically identical with original lung adenocarcinoma, suggesting that these cells are the efficient tools to generate preclinical lung tumor mouse model. We have examined this model for evaluating the efficiency of chemotherapeutics and signaling pathways involved in tumor growth regulation. Citation Format: Young-Ah Suh, Minsuh Kim, Sun-Hye Lee, Chae Lim Jung, Hye-Min Mun, Ju-Hee Oh, Eun Kyung Choi, Se Jin Jang. Development of preclinical lung adenocarcinoma model. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 89. doi:10.1158/1538-7445.AM2014-89

Targeting the insulin-like growth factor-1 receptor by picropodophyllin for lung cancer chemoprevention.

Insulin-like growth factor-1 receptor (IGF-1R) is a transmembrane heterotetramer that is activated by Insulin-like growth factor 1 and is crucial for tumor transformation and survival of malignant cells. Importantly, IGF-1R overexpression has been reported in many different cancers, implicating this receptor as a potential target for anticancer therapy. Picropodophyllin (PPP) is a potent inhibitor of IGF-1R and has antitumor efficacy in several cancer types. However, the chemopreventive effect of PPP in lung tumorigenesis has not been investigated. In this study, we investigated the chemopreventive activity of PPP in a mouse lung tumor model. Benzo(a)pyrene was used to induce lung tumors, and PPP was given by nasal inhalation to female A/J mice. Lung tumorigenesis was assessed by tumor multiplicity and tumor load. PPP significantly decreased tumor multiplicity and tumor load. Tumor multiplicity and load were decreased by 52% and 78% respectively by 4 mg/ml aerosolized PPP. Pharmacokinetics analysis showed good bioavailability of PPP in lung and plasma. Treatment with PPP increased staining for cleaved caspase-3 and decreased Ki-67 in lung tumors, suggesting that the lung tumor inhibitory effects of PPP were partially through inhibition of proliferation and induction of apoptosis. In human lung cancer cell lines, PPP inhibited cell proliferation, and also inhibited phosphorylation of IGF-1R downstream targets, AKT and MAPK, ultimately resulting in increased apoptosis. PPP also reduced cell invasion in lung cancer cell lines. In view of our data, PPP merits further investigation as a promising chemopreventive agent for human lung cancer.

DNA vaccine elicits an efficient antitumor response by targeting the mutant Kras in a transgenic mouse lung cancer model.

Mutant Kras (V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog) is observed in more than 20% of non-small-cell lung cancers; however, no effective Kras target therapy is available at present. The Kras DNA vaccine may represent as a novel immunotherapeutic agent in lung cancer. In this study, we investigated the antitumor efficacy of the Kras DNA vaccine in a genetically engineered inducible mouse lung tumor model driven by Kras(G12D). Lung tumors were induced by doxycycline, and the therapeutic effects of Kras DNA vaccine were evaluated with delivery of Kras(G12D) plasmids. Mutant Kras(G12D) DNA vaccine significantly decreased the tumor nodules. A dominant-negative mutant Kras(G12D)N17, devoid of oncogenic activity, achieved similar therapeutic effects. The T-helper 1 immune response was enhanced in mice treated with Kras DNA vaccine. Splenocytes from mice receiving Kras DNA vaccine presented an antigen-specific response by treatment with peptides of Kras but not Hras or OVA. The number of tumor-infiltrating CD8(+) T cells increased after Kras vaccination. In contrast, Kras DNA vaccine was not effective in the lung tumor in transgenic mice, which was induced by mutant L858R epidermal growth factor receptor. Overall, these results indicate that Kras DNA vaccine produces an effective antitumor response in transgenic mice, and may be useful in treating lung cancer-carrying Ras mutation.

Diverse cells at the origin of lung adenocarcinoma

Oncogenic mutations in Kirsten rat sarcoma viral oncogene homologue (K-RAS) are found in a broad range of aggressive cancers in many tissues and are common in the most prevalent form of lung cancer, adenocarcinoma (1). Despite knowledge of K-RAS mutations for many years, patients with K-RAS mutant tumors remain without an effective targeted therapy option. This has generated considerable interest in the mechanisms of oncogenesis and the cell types susceptible to this form of transformation. In PNAS, Mainardi et al. (2) and Sutherland et al. (3) take complementary approaches to interrogate the ability of different epithelial cell populations to give rise to proliferative lesions and tumors in the lung. Like earlier studies by Xu et al., also published in PNAS (4), the authors conclude that several distal lung epithelial cell types are potentially capable of hyperproliferation or tumor initiation in response to oncogenic K-Ras activation. Taken together with the first reports of K-Ras–induced lung tumors in mouse models (5, 6), the important take-home message is that the precise identity of cells that are transformed and the kind of tumors that are generated depend on multiple factors. These include the cell type in which K-Ras is activated, the developmental timing, the potential for inflammation by use of adenoviral vectors, and the specific genetic modifiers. These results will help to inform ideas about tumor initiation in the human lung.

Stat3 Downstream Gene Product Chitinase 3-Like 1 Is a Potential Biomarker of Inflammation-induced Lung Cancer in Multiple Mouse Lung Tumor Models and Humans

Over-activation of the signal transducers and activators of the transcription 3 (Stat3) pathway in lung alveolar type II (AT II) epithelial cells induces chronic inflammation and adenocarcinoma in the lung of CCSP-rtTA/(tetO)7-CMV-Stat3C bitransgenic mice. One of Stat3 downstream genes products, chitinase 3-like 1 (CHI3L1) protein, showed increased concentration in both bronchioalveolar lavage fluid (BALF) and blood of doxycycline-treated CCSP-rtTA/(tetO)7-CMV-Stat3C bitransgenic mice. When tested in other inflammation-induced lung cancer mouse models, the CHI3L1 protein concentration was also highly increased in BALF and blood of these models with tumors. Immunohistochemical staining showed strong staining of CHI3L1 protein around tumor areas in these mouse models. Analysis of normal objects and lung cancer patients revealed a significant elevation of CHI3L1 protein concentration in human serum samples from all categories of lung cancers. Furthermore, recombinant CHI3L protein stimulated proliferation and growth of Lewis lung cancer cells. Therefore, secretory CHI3L1 plays an important role in inflammation-induced lung cancer formation and potentially serve as a biomarker for lung cancer prediction. Based on our previous publication and this work, this is the first animal study linking overexpression of CHI3L1 to various lung tumor mouse models. These models will facilitate identification of additional biomarkers to predict and verify lung cancer under various pathogenic conditions, which normally cannot be done in humans.

Abstract 3983: Resuscitating immune surveillance in cancer.

Abstract Cancer growth interferes with the Notch signaling that plays diverse roles in lymphocyte commitment and differentiation, oncogenesis, and peripheral immune responses. Our studies show that the stimulation of hematopoietic Notch signaling following administration of a prototypic therapeutic agent clustered multivalent Delta-like Notch ligand (DLL1), in mouse lung tumor models can correct tumor-induced defects in lymphocyte differentiation and improve antitumor lymphocyte responses, without increasing tumor cell proliferation. Moreover, since the Notch signaling complex is inactivated via the proteasome, its inhibitor bortezomib, amongst its other potential effects, may sustain DLL1-mediated pharmacological activation of the Notch signaling. Our data demonstrate that the proteasome inhibitor bortezomib can selectively sensitize solid tumors to apoptotic signals by upregulating death receptors on tumor cells and amplifying caspase-8 activation in the extrinsic cell death pathway, without any adverse effect on the antigen-specific T cell proliferative or cytolytic functions in an in vivo setting. In the current study, we investigated the effects of bortezomib and DLL1 on Notch receptor/ligand system and its downstream signaling network with an aim to enhance cancer immunotherapy. Results show that bortezomib affects the expression of notch receptors and ligands differentially in lymphocytes and in a wide range of solid tumor cells: 4T1, PyMT, MDA-MB-231, C26, LLC, D459, and Renca-HA. Specifically, the expression of Notch 4 receptor and its ligand Jagged 1 was reduced in bortezomib-treated tumor cells. In addition, bortezomib treatment of tumor cells modulated Notch downstream targets Hes1, Hes3, Hey1, Deltex1 and Deltex3, which act as transcriptional regulators of tissue-specific differentiation. bortezomib also modulated the phosphorylation of Erk1/2 MAP kinases and AKT suggesting that bortezomib may mediate its effects through downstream phosphorylation of Erk targets, such as STATs and NFkB, or PI3K, which are key players in signaling cross-talk and intersect with Notch signaling. Noreover, bortezomib administration increased the expression of Notch target Hes1 in thymus, lymph node and spleen of tumor-bearing mice, suggesting a potential synergistic action of bortezomib and DLL1 activation of Notch signaling. These results suggest that tumor cell-death sensitizing bortezomib and pharmacological DLL1 cluster activating immunostimulatory Notch in tumor-bearing host follow common signal transduction pathways and can synergize in antitumor activity. These findings offer a novel three-pronged combinatorial therapeutic approach of immunostimulatory Notch ligand DLL1 and bortezomib to abrogate the immunosuppressive circuitries operating in the tumor microenvironment with a potential to reduce tumor burden and resuscitate tumor-specific immunity. Citation Format: Duafalia F. Dudimah, Roman V. Uzhachenko, Samuel T. Pellom, Asel K. Biktasova, Mikhail M. Dikov, David P. Carbone, Anil Shanker. Resuscitating immune surveillance in cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3983. doi:10.1158/1538-7445.AM2013-3983

Therapeutic Potential of Andrographolide Isolated from the Leaves ofAndrographis paniculataNees for Treating Lung Adenocarcinomas

Andrographolide is one of the major diterpene lactones found in Andrographis paniculata Nees and exhibits remarkable inhibitory effects on various cancers. In this study, the antipulmonary cancer effects of andrographolide were studied in a lung tumor mouse model induced by human vascular endothelial growth factor A 165 (hVEGF-A165). These results demonstrated that andrographolide significantly reduced the expression of hVEGF-A165 compared with a mock group in the Clara cells of the lungs. In addition, andrographolide also decreased tumor formation by reducing VEGF, EGFR, Cyclin A, and Cyclin B expression on the transcriptional and translational levels. These results indicated that andrographolide treatment on the overexpression of VEGF can arrest the cell cycle, which induced pulmonary tumors in transgenic mice. In conclusion, the antiangiogenesis and chemotherapeutic potential of andrographolide may provide a cure for pulmonary tumors in the future.

Abstract ED02-02: Notch defines the tumor initiating cell in non-small cell lung cancer

Abstract We investigated heterogeneity of tumorigenic capacity in KrasG12D and KrasG12D; Trp53 fl/fl mouse models of non-small cell lung cancer. Loss of Trp53 greatly enhances self-renewal in vitro and tumor propagating capacity in vivo. A conserved set of markers including CD24, ITGB4 and Notch enriches for a rare population of tumor initiating cells (TICs) in tumors driven by oncogenic Kras regardless of disease stage, or the presence or absence of Trp53. Notch marks TICs and Notch signaling is also required for their self-renewal and tumor propagating capacity. Using primary human NSCLC ex vivo cultures, we demonstrate a role for Notch signaling in the self-renewal of human tumor cells. Using multiple methods of Notch3 specific inhibition we demonstrate a Trp53-independent role for Notch3 in the maintenance of TICs in mouse lung tumor models. Citation Format: Yanyan Zheng, Cecile de la Cruz, Leanne C. Sayles, Chris Alleyn-Chin, Tim D. Knaak, Marty Bigos, Yue Xu, Chuong D Hoang, Joseph Shrager, E. Alejandro Sweet-Cordero, Erica L. Jackson,. Notch defines the tumor initiating cell in non-small cell lung cancer. [abstract]. In: Proceedings of the Eleventh Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2012 Oct 16-19; Anaheim, CA. Philadelphia (PA): AACR; Cancer Prev Res 2012;5(11 Suppl):Abstract nr ED02-02.