Correlations between nuclear and fluorescent Imaging of mammary tumors in mice

Progress with new imaging technologies permits the study of biological processes both \textit{in vivo} and noninvasively. Two systems, a position-sensitive gamma camera and a cooled-CCD camera have been applied in this work. A C3H strain of mouse carrying the Mouse Mammary Tumor Virus (MMTV) was imaged using 800 nm Q-tracker fluorescent dots conjugated to a peptide targeting integrin $\alpha \upsilon \quad \beta$ \c{C} a mammary marker for angiogenesis. We subsequently imaged with the gamma camera to detect low levels of $^{125}$I distribution, and hence, the activity of a trans-membrane protein called the sodium iodide symporter (NIS) responsible for iodine transport. Preliminary results indicate that the biodistribution of the tagged Q-tracker dots and $^{125}$I co-localize very early in seemingly normal mammary glands of infected MMTV mice, while in larger palpable tumors the Q-dot signals are less apparent in comparison with the$^{125}$I signal.