Whole-body Fluorescence Imaging Research Articles

Real-time GFP imaging of spontaneous HT-1080 fibrosarcoma lung metastases.

Metastasis to the lung is often a lethal event in sarcoma as well as other cancers. We report here a new animal model of sarcoma enabling the external real-time fluorescence imaging of spontaneous lung metastasis. The human fibrosarcoma cell line HT-1080 was transduced with the green fluorescent protein (GFP) gene. HT-1080-GFP cells were injected into the right hind footpad of severe combined immunodeficient (SCID) mice. The lung metastases were evaluated by whole-body fluorescence imaging as well as direct-view imaging in live animals through a skin-flap window over the chest wall. Spontaneous lung metastases were observed on the lungs of 11 of 12 mice. SCID mice well tolerated the skin-flap procedure enabling real-time imaging of spontaneous lung metastases with a resolution of approximately 50-100 microm. This procedure enabled external imaging at the micrometastasis level. Real-time evaluation of spontaneous lung metastasis in the same animals should allow drug evaluation and mechanistic studies not previously possible.

Whole-body fluorescence imaging with green fluorescence protein.

AbstractCurrent methods for external imaging of internally growing tumors include X-rays, magnetic resonance imaging (MRI), and ultrasonography. Although these methods are well suited for the noninvasive imaging of large-scale structures in the human body, they have limitations in the investigation of internal, actively growing tumors. In particular, monitoring growth and metastatic dissemination by these methods is impractical, since they either use potentially harmful irradiation, or require harsh contrast agents, and therefore cannot be repeated on a frequent or real-time basis.KeywordsGreen Fluorescent ProteinGreen Fluorescent Protein ExpressionGreen Fluorescent Protein FluorescenceSurgical SutureLewis Lung Carcinoma CellThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Visualizing gene expression by whole-body fluorescence imaging.

Transgene expression in intact animals now can be visualized by noninvasive techniques. However, the instruments and protocols developed so far have been formidable and expensive. We describe here a system for rapidly visualizing transgene expression in major organs of intact live mice that is simple, rapid, and eminently affordable. Green fluorescent protein (GFP) is expressed in the cells of brain, liver, pancreas, prostate, and bone, and its fluorescence is encoded in whole-body optical images. For low-magnification images, animals are illuminated atop a fluorescence light box and directly viewed with a thermoelectrically cooled color charge-coupled device camera. Higher-magnification images are made with the camera focused through an epi-fluorescence dissecting microscope. Both nude and normal mice were labeled by directly injecting 8 x 10(10) plaque-forming units/ml of adenoviral GFP in 20-100 microl PBS and 10% glycerol into either the brain, liver, pancreas, prostate, or bone marrow. Within 5-8 h after adenoviral GFP injection, the fluorescence of the expressed GFP in brain and liver became visible, and whole-body images were recorded at video rates. The GFP fluorescence continued to increase for at least 12 h and remained detectable in liver for up to 4 months. The system's rapidity of image acquisition makes it capable of real-time recording. It requires neither exogenous contrast agents, radioactive substrates, nor long processing times. The method requires only that the expressed gene or promoter be fused or operatively linked to GFP. A comparatively modest investment allows the study of the therapeutic and diagnostic potential of suitably tagged genes in relatively opaque organisms.

883. Device for evacuation of an ionic valve: E G Bobrov and V I Pakhomov, USSR Pat Cert No 164366, published Sept 1964, (in Russian)

The early detection of premalignant lesions and cancers are very important for improving the survival of patients with gastric malignancies. Confocal laser endomicroscopy (CLE) is a novel imaging tool for achieving real-time microscopy during the ongoing endoscopy at subcellular resolution. In the present study, to evaluate the feasibility of real-time molecular imaging of GEBP11 by CLE in gastric cancer, CLE was performed on two types of tumor-bearing mice models, as well as surgical specimens of patients with gastric cancer, after the application of GEBP11. A whole-body fluorescent imaging device was first used to screen for the strongest specific fluorescent signal in xenograft models. Next, the tumor sites, as well as human tissues, were scanned with CLE. After this, targeted specimens were obtained for fluorescence microscopy and histology. We confirmed that GEBP11 could specifically bind to co-HUVECs by means of CLE in cell experiments. Thereafter, a specific signal was observed in both subcutaneous and orthotopic xenograft models in vivo after the injection of FITC-GEBP11 via tail vein, whereas the group injected with FITC-URP showed no fluorescent signals. In human tissues, a specific signal of GEBP11 was observed in 26/28 neoplastic specimens and in 8/28 samples of non-neoplastic specimens from the patients (p < 0.01). The findings from ex vivo immunofluorescence microscopy of cryostat sections correlated well with that obtained by CLE. These findings indicate that the peptide, GEBP11, might be a potential candidate for the molecular imaging of gastric cancer.