An Au-Se Nanoprobe for Evaluation of the Invasive Potential of Breast Cancer Cells via Imaging the Sequential Activation of uPA and MMP-2
Urokinase-type plasminogen activator (uPA) has been shown to activate matrix metalloproteinase-2 (MMP-2) that leads to breast cancer cells’ migration and invasion. Overexpressed uPA and MMP-2 were regarded as signs of malignant tumor in clin-ical practice. Therefore, real-time monitoring the sequential activation of these two signal molecules may have important implications for evaluation of the invasive potential and tumor progression of breast cancer. However, due to the complicated intracellular environment, visualizing the dynamic changes of protein expression levels in living cells with a noninvasive method is still a great challenge. Here, a novel gold-selenium (Au-Se) fluorescent nanoprobe with excellent selectivity and strong anti-interference capability was designed for simultaneously in situ imaging of uPA and MMP-2 and real-time monitoring their changes in living cells. The imaging results demonstrates that the nanoprobe possessed better prevention of glutathione interference compared to the conventional Au-S nanoprobe, thus applying to actually reflect the the expression level of uPA and MMP-2 in different breast cancer cells. Furthermore, the Au-Se nanoprobe could visually present the activation process of the two signal molecules, which played as a dual role of insurance for invasiveness evaluation of breast bancer cells. Overall, our work offered a visual biomarker detection method for judgment of breast cancer malignancy degree, and also provided an effective strategy to investigate the relationships among signal molecules of other signaling pathway in the future.