Validity of Bioluminescence Measurements for Noninvasive in Vivo Imaging of Tumor Load in Small Animals

Abstract

A relatively new strategy to longitudinally monitor tumor load in intact animals and the effects of therapy is noninvasive bioluminescence imaging (BLI). The validity of BLI for quantitative assessment of tumor load in small animals is critically evaluated in the present review. Cancer cells are grafted in mice or rats after transfection with a luciferase gene—usually that of a firefly. To determine tumor load, animals receive the substrate agent luciferin intraperitoneally, which luciferase converts into oxyluciferin in an ATP-dependent manner. Light emitted by oxyluciferin in viable cancer cells is captured noninvasively with a highly sensitive charge-coupled device (CCD) camera. Validation studies indicate that BLI is useful to determine tumor load in the course of time, with each animal serving as its own reference. BLI is rapid, easy to perform, and sensitive. It can detect tumor load shortly after inoculation, even when relatively few cancer cells (2500–10,000) are used. BLI is less suited for the determination of absolute tumor mass in an animal because of quenching of bioluminescence by tissue components and the exact location of tumors because its spatial resolution is limited. Nevertheless, BLI is a powerful tool for high-throughput longitudinal monitoring of tumor load in small animals and allows the implementation of more advanced orthotopic tumor models in therapy intervention studies with almost the same simplicity as when measuring traditional ectopic subcutaneous models in combination with calipers.

Synthesis of site-specific antibody-drug conjugates using unnatural amino acids

“…The cells were stably transduced with Firefly luciferase (F-luc) so that tumor growth rates could be determined by longitudinal noninvasive bioluminescence imaging (IVIS 200; Caliper Life Science) (40)(41)(42)(43). Eight days after mammary fat pad implantation of 2.5 × 10 5 tumor cells, the lesions emitted 10 8 photons per cm 2 /s, and the mice were grouped into anti-Her2-IgG-nAF, unconjugated anti-Her2-IgG, and DPBS (Dulbecco's PBS) treatment arms (n = 8 each).…”

Orthotopic murine model of a primary malignant bone tumor in the spine: functional, bioluminescence, and histological correlations

“…14,16 We believe that addition of the bioluminescence testing capability is a valuable adjunct to our model, since tumor growth can be tracked in vivo without requiring the euthanization of the animal for histopathological analysis. 7 Therefore, we propose that our model can be used to test therapies in different stages of disease. Therapeutic interventions aiming at prevention of bone destruction or tumoral spread to adjacent levels could be started after confirmation of tumor engraftment with bioluminescence and before the development of tail dragging.…”

Differential effects of anticoagulants on tumor development of mouse cancer cell lines B16, K1735 and CT26 in lung

“…Fidler) were used. Preparation of cell cultures, transfection with the luciferase gene and inoculation of the cells in the tail vein of mice have been described previously [30,31].…”

“…Cells were washed twice with flow-activated cell sorter (FACS)-buffer (PBS supplemented with 0.5% bovine serum albumin, 0.01% NaN 3 , and 0. 35 For all experiments, cancer cell load in lungs was measured at day 1, 7, 15 and 21 after administration of the cancer cells using noninvasive BLI as previously described [30,31]. To generate BLI by luciferase, its substrate, luciferin (Xenogen, Alameda, CA) was given intraperitoneally to the mice (150 mg/kg body weight).…”