P450 CYP1B1 mediated fluorescent tumor markers: A potentially useful approach for photodynamic therapy, diagnosis and establishing surgical margins

SummaryFluorescent tumor markers and other chemicals that concentrate in tumors and can be utilized in photodynamic therapy to yield cytotoxins in the form of reactive oxygen species have been of interest for a number of years. In addition, the use of fluorescent markers for the purpose of tumor tissue visualization continues to be of considerable interest. One of the challenges has been to achieve a high concentration of the marker or chemical in tumor tissues, ideally approaching 100% specificity, a goal that appears rarely realized. Furthermore, a high degree of localization would limit systemic side effects from general light exposure which is a problem with some photodynamic agents. It is suggested that the cytochrome P450 enzyme CYP1B1 may offer a novel solution to this problem, since it is overexpressed in tumor tissues independent of oncogenic origin, almost entirely absent in normal tissues, and through the metabolism of selected substrates may be able to generate compounds of interest in photodynamic therapy, and in addition fluorescence assisted diagnosis, tumor visualization and the establishment of margins during resection.