Citation Details

Journal Article

IVIS, 4T1-luc2

Heparan sulfate proteoglycans (HSPGs) play a key role in shaping the tumor microenvironment by presenting growth factors, cytokines, and other soluble factors that are critical for host cell recruitment and activation, as well as promoting tumor progression, metastasis, and survival. M402 is a rationally engineered, non-cytotoxic heparan sulfate (HS) mimetic, designed to inhibit multiple factors implicated in tumor-host cell interactions, including VEGF, FGF2, SDF-1alpha, P-selectin, and heparanase. A single s.c. dose of M402 effectively inhibited seeding of B16F10 murine melanoma cells to the lung in an experimental metastasis model. Fluorescent-labeled M402 demonstrated selective accumulation in the primary tumor. Immunohistological analyses of the primary tumor revealed a decrease in microvessel density in M402 treated animals, suggesting anti-angiogenesis to be one of the mechanisms involved in-vivo. M402 treatment also normalized circulating levels of myeloid derived suppressor cells in tumor bearing mice. Chronic administration of M402, alone or in combination with cisplatin or docetaxel, inhibited spontaneous metastasis and prolonged survival in an orthotopic 4T1 murine mammary carcinoma model. These data demonstrate that modulating HSPG biology represents a novel approach to target multiple factors involved in tumor progression and metastasis.

Journal Article

Animals; Bioware; Disease Susceptibility; DNA, Bacterial; Lung; Mannose-Binding Lectin; Mice; Mice, Knockout; Reference Values; Reverse Transcriptase Polymerase Chain Reaction; Spleen; Staphylococcal Infections; Xen8.1

Gram-positive organisms like Staphylococcus aureus are a major cause of morbidity and mortality worldwide. Humoral response molecules together with phagocytes play a role in host responses to S. aureus. The mannose-binding lectin (MBL, also known as mannose-binding protein) is an oligomeric serum molecule that recognizes carbohydrates decorating a broad range of infectious agents including S. aureus. Circumstantial evidence in vitro and in vivo suggests that MBL plays a key role in first line host defense. We tested this contention directly in vivo by generating mice that were devoid of all MBL activity. We found that 100% of MBL-null mice died 48 h after exposure to an intravenous inoculation of S. aureus compared with 45% mortality in wild-type mice. Furthermore, we demonstrated that neutrophils and MBL are required to limit intraperitoneal infection with S. aureus. Our study provides direct evidence that MBL plays a key role in restricting the complications associated with S. aureus infection in mice and raises the idea that the MBL gene may act as a disease susceptibility gene against staphylococci infections in humans.

Journal Article

matrix metalloproteinase; neuroendocrine; prostate cancer; metatasis

Prostate cancer is the leading form of cancer in men. Prostate tumors often contain neuroendocrine differentiation, which correlates with androgen-independent progression and poor prognosis. Matrix metalloproteinases (MMP), a family of enzymes that remodel the microenvironment, are associated with tumorigenesis and metastasis. To evaluate MMPs during metastatic prostatic neuroendocrine cancer development, we used transgenic mice expressing SV40 large T antigen in their prostatic neuroendocrine cells, under the control of transcriptional regulatory elements from the mouse cryptdin-2 gene (CR2-TAg). These mice have a stereotypical pattern of tumorigenesis and metastasis. MMP-2, MMP-7, and MMP-9 activities increased concurrently with the transition to invasive metastatic carcinoma, but they were expressed in different prostatic cell types: stromal, luminal epithelium, and macrophages, respectively. CR2-TAg mice treated with AG3340/Prinomastat, an MMP inhibitor that blocks activity of MMP-2, MMP-9, MMP-13, and MMP-14, had reduced tumor burden. CR2-TAg animals were crossed to mice homozygous for null alleles of MMP-2, MMP-7, or MMP-9 genes. At 24 weeks CR2-TAg; MMP-2-/- mice showed reduced tumor burden, prolonged survival, decreased lung metastasis, and decreased blood vessel density, whereas deficiencies in MMP-7 or MMP-9 did not influence tumor growth or survival. Mice deficient for MMP-7 had reduced endothelial area coverage and decreased vessel size, and mice lacking MMP-9 had increased numbers of invasive foci and increased perivascular invasion, as well as decreased tumor blood vessel size. Together, these results suggest distinct contributions by MMPs to the progression of aggressive prostate tumor and to helping tumors cleverly find alternative routes to malignant progression.

Journal Article

Administration, Intranasal; Animals; Bioware; Disease Models, Animal; Female; Humans; Immunohistochemistry; Intracellular Fluid; Lymphoid Tissue; Mice; Mice, Inbred BALB C; Nasal Mucosa; Nasopharynx; Palatine Tonsil; pXen-5; Streptococcal Infections; Streptococcus pyogenes

Human tonsils are suspected to be an antibiotic-impervious human reservoir for group A streptococcus. An intranasal infection model in mice and a bioluminescent-tagged strain were used to investigate this possibility. Viable streptococci were predominantly found both intra- and extracellularly in nasal-associated lymphoid tissue (NALT), a human tonsil homologue. Ulex europaeus-1, a membranous (M) cell-specific lectin, identified cells harboring streptococci at the epithelial surface of NALT and blocked bacterial colonization of this tissue. These results suggest that M cells in NALT transport this Gram-positive pathogen across the epithelial layers in a manner similar to those in Peyer's patches, which permit enteric pathogens to invade deeper tissues from the gastrointestinal tract.

Journal Article

IVIS, Xenogen, Xen7, Xen35

Streptococcus pneumoniae is a leading cause of invasive bacterial disease. This is the first study to examine the expression of S. pneumoniae genes in vivo by using whole-genome microarrays available from The Institute for Genomic Research. Total RNA was collected from pneumococci isolated from infected blood, infected cerebrospinal fluid, and bacteria attached to a pharyngeal epithelial cell line in vitro. Microarray analysis of pneumococcal genes expressed in these models identified body site-specific patterns of expression for virulence factors, transporters, transcription factors, translation-associated proteins, metabolism, and genes with unknown function. Contributions to virulence predicted for several unknown genes with enhanced expression in vivo were confirmed by insertion duplication mutagenesis and challenge of mice with the mutants. Finally, we cross-referenced our results with previous studies that used signature-tagged mutagenesis and differential fluorescence induction to identify genes that are potentially required by a broad range of pneumococcal strains for invasive disease.