A label for a dying cell
Researchers from the University of Notre Dame and the Medical Institute at the University of Washington (USA) have demonstrated the possibility of selective binding of a synthetic fluorescent label with necrosis foci in prostate and breast tumors in live animals.
Biological objects and water transmit long-wave (near) infrared radiation more easily than light waves of other ranges, which makes it possible to visualize the glow at a depth of several centimeters in the tissues of living organisms. In a previous paper (Optical Imaging of Bacterial Infection in Living Mice Using a Fluorescent Near-Infrared Molecular Probe) by the same group of researchers working under the guidance of Professors Bradley D. Smith and Emil T. Hofman, a method for visualizing cells dying as a result of bacterial infection using a label was described, called PSS-794, containing a zinc(II)-dipicolylamine (Zn-DPA) complex.
In Bryan A. Smith et al. Optical Imaging of Mammary and Prostate Tumors in Living Animals using a Synthetic Near Infrared Zinc(II)-Dipicolylamine Probe for Anionic Cell Surfaces, published in the January issue of the Journal of the American Chemical Society, scientists demonstrated how PSS-794 binds to the anionic surfaces of dying and deceased cells in human xenografts – tumors, transplanted to rats and mice. Fluorophores introduced to control animals that were not associated with Zn-DPA complexes did not accumulate in tumors. Analysis of the distribution of the fluorescent label in prostate tumor samples on tissue sections of the studied rats showed that the label accumulated in the areas of tumor necrosis. These data confirmed the results of microscopic examination, which demonstrated the selective binding of PSS-794 with negatively charged surfaces of dead and necrotizing cells.
The presented study will allow in the near future to create optical tags, with the help of which it will be possible to noninvasively determine the number and type of cells dying inside tumors. Techniques based on the use of such labels will enable practitioners to accurately determine the condition of tumors, the stage of cancer development, as well as evaluate the effectiveness of therapy.
Portal "Eternal youth" http://vechnayamolodost.ru based on University of Notre Dame: New paper describes important advance in imaging of cell death01.02.2010