Citation Details

Journal Article

HCT-116-luc2, IVIS, Bioware, HCT116-luc2, Animals; Antibodies, Monoclonal/*immunology; Antibody-Dependent Cell Cytotoxicity/immunology; Carcinoma, Non-Small-Cell Lung/drug therapy; Carcinoma, Squamous Cell/drug therapy; Cell Line, Tumor; Colorectal Neoplasms/drug therapy; Humans; Immediate-Early Proteins/*immunology; Killer Cells, Natural/*immunology; Lymphocyte Activation/immunology; Melanoma/drug therapy; Mice; Mice, Nude; Mice, SCID; Molecular Targeted Therapy/*methods; Protein Tyrosine Phosphatases/*immunology; Recombinant Fusion Proteins/immunology/pharmacology/therapeutic use

Antibodies are considered as 'magic bullets' because of their high specificity. It is believed that antibodies are too large to routinely enter the cytosol, thus antibody therapeutic approach has been limited to extracellular or secreted proteins expressed by cancer cells. However, many oncogenic proteins are localized within the cell. To explore the possibility of antibody therapies against intracellular targets, we generated a chimeric antibody targeting the intracellular PRL-3 oncoprotein to assess its antitumor activities in mice. Remarkably, we observed that the PRL-3 chimeric antibody could efficiently and specifically reduce the formation of PRL-3 expressing metastatic tumors. We further found that natural killer (NK) cells were important in mediating the therapeutic effect, which was only observed in a nude mouse model (T-cell deficient), but not in a Severe Combined Immunodeficiency' (scid ) mouse model (B- and T-cell deficient), indicating the anticancer effect also depends on host B-cell activity. Our study involving 377 nude and scid mice suggest that antibodies targeting intracellular proteins can be developed to treat cancer.

Journal Article

Sindbis virus; viral vector; vascular leakiness; molecular imaging; chemotherapy; cancer

Genetic instability of cancer cells generates resistance after initial responses to chemotherapeutic agents. Several oncolytic viruses have been designed to exploit specific signatures of cancer cells, such as important surface markers or pivotal signaling pathways for selective replication. It is less likely for cancer cells to develop resistance given that mutations in these cancer signatures would negatively impact tumor growth and survival. However, as oncolytic viral vectors are large particles, they suffer from inefficient extravasation from tumor blood vessels. Their ability to reach cancer cells is an important consideration in achieving specific oncolytic targeting and potential vector replication. Our previous studies indicated that the Sindbis viral vectors target tumor cells by the laminin receptor. Here, we present evidence that modulating tumor vascular leakiness, using VEGF and/or metronomic chemotherapy regimens, significantly enhances tumor vascular permeability and directly enhances oncolytic Sindbis vector targeting in tumor models. Because host-derived vascular endothelium cells are genetically stable and less likely to develop resistance to chemotherapeutics, a combined metronomic chemotherapeutics and oncolytic vector regimen should provide a new approach for cancer therapy. This mechanism could explain the synergistic treatment outcomes observed in clinical trials of combined therapies.

Journal Article

IntegriSense, Animals; Cell Line, Tumor; *Diagnostic Imaging; Female; Fluorescence; Fluorescent Dyes/*diagnostic use; Humans; Integrin alphaVbeta3/*metabolism; Luciferases/metabolism; Mammary Neoplasms, Experimental/*diagnosis/metabolism; Mice; Mice, Nude; Spectroscopy, Near-Infrared

BACKGROUND: This study was designed to improve the surgical procedure and outcome of cancer surgery by means of real-time molecular imaging feedback of tumor spread and margin delineation using targeted near-infrared fluorescent probes with specificity to tumor biomarkers. Surgical excision of cancer often is confronted with difficulties in the identification of cancer spread and the accurate delineation of tumor margins. Currently, the assessment of tumor borders is afforded by postoperative pathology or, less reliably, intraoperative frozen sectioning. Fluorescence imaging is a natural modality for intraoperative use by directly relating to the surgeon's vision and offers highly attractive characteristics, such as high-resolution, sensitivity, and portability. Via the use of targeted probes it also becomes highly tumor-specific and can lead to significant improvements in surgical procedures and outcome. METHODS: Mice bearing xenograft human tumors were injected with alphavbeta3-integrin receptor-targeted fluorescent probe and in vivo visualized by using a novel, real-time, multispectral fluorescence imaging system. Confirmatory ex vivo imaging, bioluminescence imaging, and histopathology were used to validate the in vivo findings. RESULTS: Fluorescence images were all in good correspondence with the confirming bioluminescence images in respect to signal colocalization. Fluorescence imaging detected all tumors and successfully guided total tumor excision by effectively detecting small tumor residuals, which occasionally were missed by the surgeon. Tumor tissue exhibited target-to-background ratio of ~4.0, which was significantly higher compared with white-light images representing the visual contrast. Histopathology confirmed the capability of the method to identify tumor negative margins with high specificity and better prediction rate compared with visual inspection. CONCLUSIONS: Real-time multispectral fluorescence imaging using tumor specific molecular probes is a promising modality for tumor excision by offering real time feedback to the surgeon in the operating room.

Journal Article

*Breast Cancer; *Chemotherapy; *Genes; *Luciferase; Anatomy and Physiology; Biochemistry; Bioware; Cells(Biology); Diseases; Drugs; Efficacy; Gel Polymers; Gels; Growth(Physiology); Humans; Image Processing; In Vitro Analysis.; In Vivo Analysis; Luciferase Genes; Medicine and Medical Research; Metastasis; Mouse Models; Paclitaxel Sensitivity; Poloxamer Polymers; Polymers; Preclinical Evaluations; surgery; Synergism; Toxicity; Tumor Cell Lines

This project evaluated paclitaxel chemotherapy delivery from a gel polymer system placed into a wound bed following conservative (marginal) surgical removal of human breast cancers grown in nude mice. This delivery method was shown to control local tumor disease as well as assist in control of systemic metastasis. We established 5 human breast cancer cell lines within our laboratory. We elected purchase and implement a unique (luciferase) imaging system which allows in vivo imaging of tumor growth and metastasis (and subsequently decrease animal use). Tumor cell lines were transfected with the luciferase gene. In vitro testing of cell lines established paclitaxel sensitivity and showed a synergistic effect of delivering paclitaxel by the poloxamer polymer, especially for the chemotherapy resistant cell line, MCF-7-ADR. We completed the simultaneous evaluation of local and systemic toxicity, local, regional and systemic distribution and local and systemic efficacy of locally delivered paclitaxel chemotherapy following tumor removal using the MCF-7-ADR cell line in nude mice. Intracavitary administration of taxol in poloxamer was well tolerated (locally and systemically) afld resulted in significantly improved control of local tumor regrowth and comparable control of metastasis following marginal tumor removal as compared to intravenous paclitaxel (parent drug) . Sustained drug levels (from polymer delivery) were seen in plasma and liver tissue at 60 days.

Journal Article

Bioware; pXen-13

BACKGROUND There is no safe, effective human vaccine against brucellosis. Live attenuated Brucella strains are widely used to vaccinate animals. However these live Brucella vaccines can cause disease and are unsafe for humans. Killed Brucella or subunit vaccines are not effective in eliciting long term protection. In this study, we evaluate an approach using a live, non-pathogenic bacteria (E. coli) genetically engineered to mimic the brucellae pathway of infection and present antigens for an appropriate cytolitic T cell response. METHODS E. coli was modified to express invasin of Yersinia and listerialysin O (LLO) of Listeria to impart the necessary infectivity and antigen releasing traits of the intracellular pathogen, Brucella. This modified E. coli was considered our vaccine delivery system and was engineered to express Green Fluorescent Protein (GFP) or Brucella antigens for in vitro and in vivo immunological studies including cytokine profiling and cytotoxicity assays. RESULTS The E. coli vaccine vector was able to infect all cells tested and efficiently deliver therapeutics to the host cell. Using GFP as antigen, we demonstrate that the E. coli vaccine vector elicits a Th1 cytokine profile in both primary and secondary immune responses. Additionally, using this vector to deliver a Brucella antigen, we demonstrate the ability of the E. coli vaccine vector to induce specific Cytotoxic T Lymphocytes (CTLs). CONCLUSION Protection against most intracellular bacterial pathogens can be obtained mostly through cell mediated immunity. Data presented here suggest modified E. coli can be used as a vaccine vector for delivery of antigens and therapeutics mimicking the infection of the pathogen and inducing cell mediated immunity to that pathogen.