Citation Details

Journal Article

IntegriSense, Animals; Antigens, CD31/metabolism; Capillaries/metabolism; Diagnostic Imaging/*methods; Femoral Artery/surgery; Fluorescent Dyes/*diagnostic use/metabolism; Hindlimb/*blood supply/metabolism/pathology; Integrin alphaV/metabolism; Integrin alphaVbeta3/antagonists & inhibitors/metabolism; Ischemia/*pathology; Ligation; Male; Mice; Mice, Inbred Strains; Microscopy, Fluorescence; *Neovascularization, Physiologic; Plant Lectins/metabolism; Sensitivity and Specificity

Optical agents targeting alpha(v)beta(3) are potential tools to image the angiogenic response to limb ischemia. The left (L) femoral artery was ligated in 17 mice and sham surgery performed on the contralateral right (R) hindlimb. Seven days later, IntegriSense (2 nmol) was injected into 11 mice and 6 were probe controls. Six hours later, mice underwent optical imaging. Ratios of photon flux in the L/R limbs were calculated. Tissue was stained for alpha(v) , CD31, and lectin. The signal was increased in the ischemic limbs compared to contralateral legs and ratio of photon flux in L/R limb averaged 2.37. Control probe showed no hindlimb signal. IntegriSense colocalized with CD31 by dual fluorescent staining. Ratios for L/R hindlimbs correlated with quantitative lectin staining (r = 0.88, p = 0.003). Optical imaging can identify and quantify angiogenic response to hindlimb ischemia.

Journal Article

IntegriSense, Animals; Blotting, Western; Cell Proliferation/drug effects; Cells, Cultured; Colitis/chemically induced/complications; Colonic Neoplasms/etiology/genetics/*metabolism; Dextran Sulfate; Endothelial Cells/metabolism; Epithelial Cells/metabolism; Gene Expression; Humans; Immunohistochemistry; Inflammatory Bowel Diseases/genetics/*metabolism; Mice; Mice, Inbred C57BL; Mice, Knockout; Mice, Transgenic; Microscopy, Confocal; Reverse Transcriptase Polymerase Chain Reaction; STAT3 Transcription Factor/genetics/metabolism; *Signal Transduction; Up-Regulation; Vascular Endothelial Growth Factor A/genetics/metabolism/pharmacology; Vascular Endothelial Growth Factor Receptor-1/genetics/metabolism; Vascular Endothelial Growth Factor Receptor-2/genetics/*metabolism

Whereas the inhibition of vascular endothelial growth factor (VEGF) has shown promising results in sporadic colon cancer, the role of VEGF signaling in colitis-associated cancer (CAC) has not been addressed. We found that, unlike sporadic colorectal cancer and control patients, patients with CAC show activated VEGFR2 on intestinal epithelial cells (IECs). We then explored the function of VEGFR2 in a murine model of colitis-associated colon cancer characterized by increased VEGFR2 expression. Epithelial cells in tumor tissue expressed VEGFR2 and responded to VEGF stimulation with augmented VEGFR2-mediated proliferation. Blockade of VEGF function via soluble decoy receptors suppressed tumor development, inhibited tumor angiogenesis, and blocked tumor cell proliferation. Functional studies revealed that chronic inflammation leads to an up-regulation of VEGFR2 on IECs. Studies in conditional STAT3 mutant mice showed that VEGFR signaling requires STAT3 to promote epithelial cell proliferation and tumor growth in vivo. Thus, VEGFR-signaling acts as a direct growth factor for tumor cells in CAC, providing a molecular link between inflammation and the development of colon cancer.

Journal Article

IntegriSense, Animals; Bone Neoplasms/radionuclide imaging/*secondary; Diagnostic Imaging/*methods; Forecasting; Optics and Photonics/*trends; Positron-Emission Tomography/methods; Tomography, Emission-Computed, Single-Photon/methods; X-Ray Microtomography/methods; X-Rays

Optical Imaging has evolved into one of the standard molecular imaging modalities used in pre-clinical cancer research. Bone research however, strongly depends on other imaging modalities such as SPECT, PET, x-ray and muCT. Each imaging modality has its own specific strengths and weaknesses concerning spatial resolution, sensitivity and the possibility to quantify the signal. An increasing number of bone specific optical imaging models and probes have been developed over the past years. This review gives an overview of optical imaging modalities, models and probes that can be used to study skeletal complications of cancer in small laboratory animals.

Journal Article

IntegriSense, Animals; Bronchoalveolar Lavage Fluid/chemistry; Ceramides/metabolism; Female; Gene Deletion; Gene Expression Regulation/physiology; Lung/*radiation effects; Lysophospholipids/*chemistry/*pharmacology; Mice; Mice, Inbred C57BL; Mice, Knockout; *Radiation Injuries, Experimental; Receptors, Lysosphingolipid/genetics/metabolism; Sphingolipids/*metabolism; Sphingosine/*analogs & derivatives/chemistry/pharmacology

Clinically significant radiation-induced lung injury (RILI) is a common toxicity in patients administered thoracic radiotherapy. Although the molecular etiology is poorly understood, we previously characterized a murine model of RILI in which alterations in lung barrier integrity surfaced as a potentially important pathobiological event and genome-wide lung gene mRNA levels identified dysregulation of sphingolipid metabolic pathway genes. We hypothesized that sphingolipid signaling components serve as modulators and novel therapeutic targets of RILI. Sphingolipid involvement in murine RILI was confirmed by radiation-induced increases in lung expression of sphingosine kinase (SphK) isoforms 1 and 2 and increases in the ratio of ceramide to sphingosine 1-phosphate (S1P) and dihydro-S1P (DHS1P) levels in plasma, bronchoalveolar lavage fluid, and lung tissue. Mice with a targeted deletion of SphK1 (SphK1(-/-)) or with reduced expression of S1P receptors (S1PR1(+/-), S1PR2(-/-), and S1PR3(-/-)) exhibited marked RILI susceptibility. Finally, studies of 3 potent vascular barrier-protective S1P analogs, FTY720, (S)-FTY720-phosphonate (fTyS), and SEW-2871, identified significant RILI attenuation and radiation-induced gene dysregulation by the phosphonate analog, fTyS (0.1 and 1 mg/kg i.p., 2x/wk) and to a lesser degree by SEW-2871 (1 mg/kg i.p., 2x/wk), compared with those in controls. These results support the targeting of S1P signaling as a novel therapeutic strategy in RILI.

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.