Citation Details

Journal Article

Aminoquinolines; Animals; B16-F10-luc-G5 cells; Bioware; Cell Line, Tumor; Cell Proliferation; Cell Survival; Culture Media, Conditioned; dendritic cells; Humans; Interferon Type I; Leukocytes, Mononuclear; Lung; Melanoma; Mice; Neoplasms; Oligodeoxyribonucleotides; Quinolines; Subcellular Fractions; Sulfonamides; Toll-Like Receptor 7

Antitumor effects of the toll-like receptor 7 (TLR7) agonist, 852A, were evaluated. Supernatants from human peripheral blood mononuclear cells (PBMC) stimulated with 852A inhibited the proliferation of tumor cell lines Hs294T and 769-P but had no effect on others (786-O and Caki-1). Because addition of 852A directly to the Hs294T cells did not inhibit their proliferation, the mechanism(s) of inhibition of tumor cell proliferation was investigated. Low nanomolar concentrations of 852A stimulated the production of interferon-alpha (IFN-alpha), IFN-inducible protein-10 (IP-10), interleukin-1 receptor antagonist (IL-1Ra), monocyte chemotactic protein-1 (MCP-1), and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) from human PBMCs. Cytokines stimulated by submicromolar concentrations of 852A were sufficient to inhibit Hs294T proliferation. At higher concentrations (3-30 microM), 852A induced the production of IL-12p70, IL-18, and IFN-gamma. PBMC cultures depleted of plasmacytoid dendritic cells (pDC) did not produce IFN-alpha, and their conditioned medium did not inhibit Hs294T proliferation. Anti-IFN-alpha/beta receptor (IFNAR) and anti-IFN-alpha antibodies partially abrogated Hs294T proliferation inhibition by 852A-stimulated PBMC supernatants, whereas separate neutralization of TRAIL, tumor necrosis factor-alpha (TNF-alpha, IFN-gamma, IFN-beta, or IFN-omega had no effect. In vivo, six doses of 852A administration significantly delayed the onset of lung colonies in a B16 melanoma model. Thus, the results demonstrate that the TLR7 agonist 852A inhibits in vitro proliferation of some tumor cells in a pDC-dependent and IFN-alpha-dependent manner and can delay tumor growth in vivo.

Journal Article

Xen14, Xen 14, E. coli Xen14, IVIS, Animals; Cell Line, Tumor; Female; Histocompatibility Antigens Class I/genetics/*immunology; Humans; Klebsiella Infections/*immunology/prevention & control; Klebsiella pneumoniae/*immunology; Male; Mice; Mice, Inbred C57BL; Mice, Knockout

As opposed to the well established role of MHC-linked, polymorphic, class I (MHC-I) genes in adaptive immunity, a universal role for non-conventional MHC-I is unknown, thus requiring a case-by-case study. The MHC unlinked, monomorphic, but beta(2)microglobulin (beta(2)m)-associated “MHC class I related” MR1 molecule interacts with a semi-invariant TCR. The pathophysiology of this interaction or more importantly of this peculiar MHC-I remains mostly unknown. Recently it was shown that beta(2)m deficient mice were more susceptible to infection by Klebsiella pneumoniae, a widely spread Gram-negative bacteria that causes diverse and often severe ailments in man. Here we demonstrate, using both an in vivo imaging system and survival tests, the increased susceptibility to K. pneumoniae (but not to several other Gram negative bacteria) of MR1 deficient mice. This is accompanied by a consequent change in body temperature and systemic cytokine profile. Hence MR1 controls K. pneumoniae infection in vivo.

Journal Article

A549-luc-C8, A549-luc, IVIS, Bioware, ATP Citrate (pro-S)-Lyase/*antagonists & inhibitors/genetics; Animals; Apoptosis; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Combined Modality Therapy; Epithelial-Mesenchymal Transition; Female; Gene Knockdown Techniques; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors/*therapeutic use; Lung Neoplasms/*drug therapy/enzymology/pathology/*therapy; MAP Kinase Signaling System/drug effects; Mice; Mutation; Phosphatidylinositol 3-Kinases/antagonists & inhibitors; Proto-Oncogene Proteins c-akt/antagonists & inhibitors; Receptor, Epidermal Growth Factor/genetics; Signal Transduction/drug effects; Xenograft Model Antitumor Assays

ATP citrate lyase (ACL) catalyzes the conversion of cytosolic citrate to acetyl-CoA and oxaloacetate. A definitive role for ACL in tumorigenesis has emerged from ACL RNAi and chemical inhibitor studies, showing that ACL inhibition limits tumor cell proliferation and survival and induces differentiation in vitro. In vivo, it reduces tumor growth leading to a cytostatic effect and induces differentiation. However, the underlying molecular mechanisms are poorly understood and agents that could enhance the efficacy of ACL inhibition have not been identified. Our studies focus on non-small cell lung cancer (NSCLC) lines, which show phosphatidylinositol 3-kinase (PI3K)/AKT activation secondary to a mutation in the K-Ras gene or the EGFR gene. Here we show that ACL knockdown promotes apoptosis and differentiation, leading to the inhibition of tumor growth in vivo. Moreover, in contrast to most studies, which elucidate how activation/suppression of signaling pathways can modify metabolism, we show that inhibition of a metabolic pathway “reverse signals” and attenuates PI3K/AKT signaling. Additionally, we find that statins, inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, which act downstream of ACL in the cholesterol synthesis pathway, dramatically enhance the anti-tumor effects of ACL inhibition, even regressing established tumors. With statin treatment, both PI3K/AKT and the MAPK pathways are affected. Moreover, this combined treatment is able to reduce the growth of EGF receptor resistant tumor cell types. Given the essential role of lipid synthesis in numerous cancers, this work may impact therapy in a broad range of tumors.

Journal Article

A549-luc-C8, A549-luc, IVIS, Bioware

Axl is a tyrosine kinase receptor that was first identified as a transforming gene in human myeloid leukemia. Recent converging evidence suggests its implication in cancer progression and invasion for several solid tumors, including lung, breast, brain, thyroid, and pancreas. In the last decade, Axl has thus become an attractive target for therapeutic development of more aggressive cancers. An emerging class of therapeutic inhibitors is now represented by short nucleic acid aptamers. These molecules act as high affinity ligands with several advantages over conventional antibodies for their use in vivo, including their small size and negligible immunogenicity. Furthermore, these molecules can easily form conjugates able to drive the specific delivery of interfering RNAs, nanoparticles, or chemotherapeutics. We have thus generated and characterized a selective RNA-based aptamer, GL21.T that binds the extracellular domain of Axl at high affinity (12 nmol/l) and inhibits its catalytic activity. GL21.T blocked Axl-dependent transducing events in vitro, including Erk and Akt phosphorylation, cell migration and invasion, as well as in vivo lung tumor formation in mice xenografts. In this respect, the GL21.T aptamer represents a promising therapeutic molecule for Axl-dependent cancers whose importance is highlighted by the paucity of available Axl-specific inhibitory molecules.

Journal Article

ProSense; AngioSense; AngioSpark; in vivo imaging; pancreatic cancer

BACKGROUND & AIMS: Surgical management of pancreatic cancer depends on tumor resectability and staging. This study evaluated a new in vivo technique, fiberoptic confocal fluorescence microscopy (FCFM), for detection and staging of pancreatic tumors in rats.

METHODS: FCFM was used with a protease-activated fluorescent marker (ProSense; VisEn Medical Inc, Woburn, MA) for in vivo imaging of solid organs (1.8-microm resolution) in a rat model of pancreatic ductal adenocarcinoma. A preliminary study described the FCFM rendering of normal and pathologic tissues. Subsequently, 2 double-blind studies compared FCFM to standard histology in (1) detection of tumors in rat models of cancer and controls and (2) detection of nodal involvement (splenic, celiac, mesenteric, and colic) 4, 5, and 6 weeks after tumor induction vs controls.

RESULTS: Tumor cells displayed a fluorescent ductal pattern compared with non-fluorescent normal pancreas or normal follicular pattern of lymph nodes (LNs). FCFM detected all the pancreatic tumors (1.7-mm mean diameter) and identified 23 LNs that contained metastases of 99 LNs examined. Standard histologic analyses resulted in 1 false-negative result in tumor detection and 2 false negatives in LN detection, whereas FCFM produced no false-negative results. Additional serial sectioning confirmed all tumors and 16 metastatic LNs; FCFM had a negative predictive value of 100% and a positive predictive value of 69.6%.

CONCLUSIONS: Real-time “virtual biopsy” using FCFM detects tumors and LN metastases with 100% sensitivity and 92.2% specificity in rats, making it a reliable technique for detection and staging of pancreatic cancer.