Journal Article

Animals; Apoptosis; B16-F10-luc-G5 cells; Bioware; Blotting, Western; Cell Line, Tumor; Escherichia coli; Female; Flow Cytometry; Gene Therapy; Genetic Vectors; Humans; Immunohistochemistry; Mice; Mice, Inbred BALB C; Mice, Nude; NCI-H460-luc2; Neoplasms; Polymerase Chain Reaction; Survival Rate; TNF-Related Apoptosis-Inducing Ligand

The tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is a potent inducer of tumor cell apoptosis, but concerns of considerable liver toxicity limit its uses in human cancer therapy. Here, we show that i.v. injected Escherichia coli DH5alpha (E. coli DH5alpha) specifically replicates in solid tumors and metastases in live animals. E. coli DH5alpha does not enter tumor cells and suits for being the vector for soluble TRAIL (sTRAIL), which induces apoptosis by activating cell-surface death receptors. With the high 'tumor-targeting' nature, we demonstrate that intratumoral (i.t.) and intravenous injection of sTRAIL-expressing E. coli DH5alpha results in the tumor-targeted release of biologically active molecules, which leads to a dramatic reduction in the tumor growth rate and the prolonged survival of tumor-bearing mice. TRAIL delivery by E. coli DH5alpha did not cause any detectable toxicity to any organs, suggesting that E. coli DH5alpha-delivered sTRAIL protein therapy may provide a feasible and effective form of treatment for solid tumors.

Journal Article

Animals; Bioware; Chronic Disease; Disease Models, Animal; Immunity, Innate; Killer Cells, Natural; Macrophages; Mice; Mice, Inbred C3H; Mice, Inbred Strains; Monocytes; Neoplasms; Neovascularization, Pathologic; Osteomyelitis; Osteosarcoma; Staphylococcal Infections; Xen36

Clinical studies over the past several years have reported that metastasis-free survival times in humans and dogs with osteosarcoma are significantly increased in patients that develop chronic bacterial osteomyelitis at their surgical site. However, the immunological mechanism by which osteomyelitis may suppress tumor growth has not been investigated. Therefore, we used a mouse model of osteomyelitis to assess the effects of bone infection on innate immunity and tumor growth. A chronic Staphylococcal osteomyelitis model was established in C3H mice and the effects of infection on tumor growth of syngeneic DLM8 osteosarcoma were assessed. The effects of infection on tumor angiogenesis and innate immunity, including NK cell and monocyte responses, were assessed. We found that osteomyelitis significantly inhibited the growth of tumors in mice, and that the effect was independent of the infecting bacterial type, tumor type, or mouse strain. Depletion of NK cells or monocytes reversed the antitumor activity elicited by infection. Moreover, infected mice had a significant increase in circulating monocytes and numbers of tumor associated macrophages. Infection suppressed tumor angiogenesis but did not affect the numbers of circulating endothelial cells. Therefore, we concluded that chronic localized bacterial infection could elicit significant systemic antitumor activity dependent on NK cells and macrophages.

Journal Article

Proteomics; mass spectrometry; plasma proteome; colorectal cancer; mouse model; in vivo imaging; ProSense

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Journal Article

IVIS, B16-F10-luc-G5, B16F10-luc-G5, B16-F10-luc, B16F10-luc,

Tumor progression is associated with the release of signaling substances from the primary tumor into the bloodstream. Tumor-derived cytokines are known to promote the mobilization and the recruitment of cells from the bone marrow, including endothelial progenitor cells (EPC). Here, we examined whether such paracrine influence could also influence the capacity of EPC to interfere with circulating metastatic cells. We therefore consecutively injected EPC pre-stimulated by tumor conditioned medium (CM-EPC) and luciferase-expressing B16 melanoma cells to mice. A net decrease in metastases spreading (vs non-stimulated EPC) led us to carry out a 2D-DIGE proteomic study to identify possible mediators of EPC-driven protection. Among 33 proteins exhibiting significant changes in expression, SPARC presented the highest induction after EPC exposure to CM. We then showed that contrary to control EPC, SPARC-silenced EPC were not able to reduce the extent of metastases when injected with B16 melanoma cells. Using adhesion tests and the hanging drop assay, we further documented that cell-cell interactions between CM-EPC and melanoma cells were promoted in a SPARC-dependent manner. This interaction led to the engulfment of melanoma cells by CM-EPC, a process prevented by SPARC silencing and mimicked by recombinant SPARC. Finally, we showed that contrary to melanoma cells, the pro-metastatic human breast cancer cell line MDA-MB231-D3H2 reduced SPARC expression in human EPC and stimulated metastases spreading. Our findings unravel the influence of tumor cells on EPC phenotypes through a SPARC-driven accentuation of macrophagic capacity associated with limitations to metastatic spread.

Journal Article

Animals, B16-F10-luc2, B16F10-luc2; Coloring Agents/administration & dosage/*diagnostic use; Indocyanine Green/administration & dosage/*diagnostic use; Injections, Intradermal; Liposomes/administration & dosage; Lymphatic Metastasis; Lymphatic Vessels/metabolism/*pathology; Melanoma, Experimental/blood supply/metabolism/*pathology; Mice; Mice, Inbred C57BL; Vascular Endothelial Growth Factor C/biosynthesis

Lymphatic vessels play a major role in cancer progression and in postsurgical lymphedema, and several new therapeutic approaches targeting lymphatics are currently being developed. Thus, there is a critical need for quantitative imaging methods to measure lymphatic flow. Indocyanine green (ICG) has been used for optical imaging of the lymphatic system, but it is unstable in solution and may rapidly enter venous capillaries after local injection. We developed a novel liposomal formulation of ICG (LP-ICG), resulting in vastly improved stability in solution and an increased fluorescence signal with a shift toward longer wavelength absorption and emission. When injected intradermally to mice, LP-ICG was specifically taken up by lymphatic vessels and allowed improved visualization of deep lymph nodes. In a genetic mouse model of lymphatic dysfunction, injection of LP-ICG showed no enhancement of draining lymph nodes and slower clearance from the injection site. In mice bearing B16 luciferase-expressing melanomas expressing vascular endothelial growth factor-C (VEGF-C), sequential near-IR imaging of intradermally injected LP-ICG enabled quantification of lymphatic flow. Increased flow through draining lymph nodes was observed in mice bearing VEGF-C-expressing tumors without metastases, whereas a decreased flow pattern was seen in mice with a higher lymph node tumor burden. This new method will likely facilitate quantitative studies of lymphatic function in preclinical investigations and may also have potential for imaging of lymphedema or improved sentinel lymph detection in cancer.