An In Vivo PET Imaging Technique to Detect Tumors in a Murine Model Using Radiolabeled Antibodies

Take prostate cancer cells and inject them subcutaneously into an anesthetized,  immunocompromised nude mouse.

The lack of an immune response allows the injected cells to survive and multiply, forming a tumor.

The tumor cells overexpress a prostate-specific membrane antigen or PSMA, a cell-surface protein.

Take PSMA-specific antibodies conjugated to a radiotracer and inject them intravenously into the tail of the tumor-bearing mouse.

Antibodies reach the tumor cells and bind to PSMA, labeling the tumor.

Place the anesthetized mouse in a positron-emission tomography or PET scanner and obtain a scan.

The produced image shows the distribution of the radiotracer, highlighting areas of high antibody uptake, which correspond to the tumor location.

In male athymic nude mice, subcutaneously implant 5 x 10⁶ LNCaP prostate cancer cells, allowing these to grow to a 100 to 150 millimeter-cubed xenograft. Three to four weeks after inoculation, the tumors should be ready.

For imaging, dilute the ⁸⁹Zr-DFO-J591 radio immunoconjugate to a concentration of 1 millicuries per milliliter in 0.9% sterile saline. Next, inject 200 microliters of the ⁸⁹Zr-DFO-J591 solution into the lateral tail vein of the