Citation Details

Journal Article

IVIS, Xenogen, Xen20

C5a peptidase, also called SCPA (surface-bound C5a peptidase), is a surface-bound protein on group A streptococci (GAS), etiologic agents for a variety of human diseases including pharyngitis, impetigo, toxic shock, and necrotizing fasciitis, as well as the postinfection sequelae rheumatic fever and rheumatic heart disease. This protein is highly conserved among different serotypes and is also expressed in human isolates of group B, C, and G streptococci. Human tonsils are the primary reservoirs for GAS, maintaining endemic disease across the globe. We recently reported that GAS preferentially target nasal mucosa-associated lymphoid tissue (NALT) in mice, a tissue functionally analogous to human tonsils. Experiments using a C5a peptidase loss-of-function mutant and an intranasal infection model showed that this protease is required for efficient colonization of NALT. An effective vaccine should prevent infection of this secondary lymphoid tissue; therefore, the potential of anti-SCPA antibodies to protect against streptococcal infection of NALT was investigated. Experiments showed that GAS colonization of NALT was significantly reduced following intranasal immunization of mice with recombinant SCPA protein administered alone or with cholera toxin, whereas a high degree of GAS colonization of NALT was observed in control mice immunized with phosphate-buffered saline only. Moreover, administration of anti-SCPA serum by the intranasal route protected mice against streptococcal infection. These results suggest that intranasal immunization with SCPA would prevent colonization and infection of human tonsils, thereby eliminating potential reservoirs that maintain endemic disease.

Journal Article

IntegriSense

GTP cyclohydrolase (GCH1) is the key-enzyme to produce the essential enzyme cofactor, tetrahydrobiopterin. The byproduct, neopterin is increased in advanced human cancer and used as cancer-biomarker, suggesting that pathologically increased GCH1 activity may promote tumor growth. We found that inhibition or silencing of GCH1 reduced tumor cell proliferation and survival and the tube formation of human umbilical vein endothelial cells, which upon hypoxia increased GCH1 and endothelial NOS expression, the latter prevented by inhibition of GCH1. In nude mice xenografted with HT29-Luc colon cancer cells GCH1 inhibition reduced tumor growth and angiogenesis, determined by in vivo luciferase and near-infrared imaging of newly formed blood vessels. The treatment with the GCH1 inhibitor shifted the phenotype of tumor associated macrophages from the proangiogenic M2 towards M1, accompanied with a shift of plasma chemokine profiles towards tumor-attacking chemokines including CXCL10 and RANTES. GCH1 expression was increased in mouse AOM/DSS-induced colon tumors and in high grade human colon and skin cancer and oppositely, the growth of GCH1-deficient HT29-Luc tumor cells in mice was strongly reduced. The data suggest that GCH1 inhibition reduces tumor growth by (i) direct killing of tumor cells, (ii) by inhibiting angiogenesis, and (iii) by enhancing the antitumoral immune response.

Journal Article

HCT-116-luc2, IVIS, Bioware, HCT116-luc2

Non-thermal plasma (NTP) is generated by ionizing neutral gas molecules/atoms leading to a highly reactive gas at ambient temperature containing excited molecules, reactive species and generating transient electric fields. Given its potential to interact with tissue or cells without a significant temperature increase, NTP appears as a promising approach for the treatment of various diseases including cancer. The aim of our study was to evaluate the interest of NTP both in vitro and in vivo. To this end, we evaluated the antitumor activity of NTP in vitro on two human cancer cell lines (glioblastoma U87MG and colorectal carcinoma HCT-116). Our data showed that NTP generated a large amount of reactive oxygen species (ROS), leading to the formation of DNA damages. This resulted in a multiphase cell cycle arrest and a subsequent apoptosis induction. In addition, in vivo experiments on U87MG bearing mice showed that NTP induced a reduction of bioluminescence and tumor volume as compared to nontreated mice. An induction of apoptosis was also observed together with an accumulation of cells in S phase of the cell cycle suggesting an arrest of tumor proliferation. In conclusion, we demonstrated here that the potential of NTP to generate ROS renders this strategy particularly promising in the context of tumor treatment.

Journal Article

IntegriSense, Angiogenesis Inhibitors/therapeutic use; Animals; Diagnostic Imaging/*methods; Fluorescence; Humans; Luminescence/diagnostic use; Magnetic Resonance Angiography/methods; Magnetic Resonance Imaging/methods; Microscopy/methods; Neoplasms/*blood supply/therapy; *Neovascularization, Pathologic/pathology/ultrasonography; Positron-Emission Tomography/methods; Tomography/methods; Tomography, Emission-Computed, Single-Photon/methods; Tomography, X-Ray Computed/methods; X-Ray Microtomography/methods

Significant advances have been made in understanding the role of tumor angiogenesis and its influence on tumor progression in cancer. Based on this knowledge, a series of inhibitors of angiogenesis have been developed and evaluated in preclinical and clinical trials. Since detailed information of tumor progression in response to therapy is important to assess the efficacy of anti-tumor treatment in vivo, noninvasive imaging techniques emerge more and more as important tools to monitor alterations in tumor growth and vessel recruitment, as well as metastatic spread over time. So far, remarkable efforts have been made to improve the technical capability of these imaging modalities based on better resolution, as well as to implement multimodal approaches combining molecular with anatomical information. Advanced imaging techniques not only allow the detection and monitoring of tumor development, but also facilitate a broad understanding of the cellular and molecular events that propagate tumor angiogenesis, as well as those occurring in response to therapy. This review provides an overview of different imaging techniques in preclinical settings of oncological research and discusses their potential impact on clinical translation. Imaging modalities will be presented that have been implemented to address key biological issues by exploring tumor angiogenic processes and evaluating antiangiogenic therapy.

Journal Article

FMT, Prosense, CatB, Cathepsin B, fluorescence imaing, tomography, microCT

Inflammation as a core pathological event of atherosclerotic lesions is associated with the secretion of cathepsin proteases and the expression of alpha(v)beta(3) integrin. We employed fluorescence molecular tomographic (FMT) noninvasive imaging of these molecular activities using cathepsin sensing (ProSense, CatB FAST) and alpha(v)beta(3) integrin (IntegriSense) near-infrared fluorescence (NIRF) agents. A statistically significant increase in the ProSense and IntegriSense signal was observed within the chest region of apoE(-/-) mice (P < 0.05) versus C57BL/6 mice starting 25 and 22 weeks on high cholesterol diet, respectively. In a treatment study using ezetimibe (7 mg/kg), there was a statistically significant reduction in the ProSense and CatB FAST chest signal of treated (P < 0.05) versus untreated apoE(-/-) mice at 31 and 21 weeks on high cholesterol diet, respectively. The signal of ProSense and CatB FAST correlated with macrophage counts and was found associated with inflammatory cells by fluorescence microscopy and flow cytometry of cells dissociated from aortas. This report demonstrates that cathepsin and alpha(v)beta(3) integrin NIRF agents can be used as molecular imaging biomarkers for longitudinal detection of atherosclerosis, and cathepsin agents can monitor anti-inflammatory effects of ezetimibe with applications in preclinical testing of therapeutics and potentially for early diagnosis of atherosclerosis in patients.