Real-Time In Vivo Confocal Fluorescence Imaging of Prostate Cancer Bone-Marrow Micrometastasis Development at the Cellular Level in Nude Mice

In the present report, we demonstrate in vivo fluorescence imaging of bone-marrow micrometastasis of prostate cancer at the cellular level in nude mice. PC-3 human prostate cancer cells labeled with green fluorescent protein (GFP) or red fluorescent protein (RFP) were injected into the left ventricle or intratibial bone marrow of nude mice. PC-3-GFP, as well as selected high metastatic variants of PC-3-GFP, PC-3-GFP-BM6 or PC-3-RFP were visualized by real-time fluorescence imaging, to traffic and grow in the bone marrow. Formation of bone marrow micrometastasis could be imaged at the single-cell level in live mice, using confocal microscopy. The ability to track bone marrow micrometastasis in real time at the cellular level provides a visual target for evaluating new therapeutics for this recalcitrant disease. J. Cell. Biochem. 117: 2533–2537, 2016.