Buffalo, NY-- Research by University at Buffalo (UB) scientists demonstrates a biophotonic imaging approach capable of monitoring in real-time the transformations that cellular macromolecules undergo during apoptosis, or programmed cell death. The work could help realize the potential of customized molecular medicine, in which chemotherapy, for example, can be precisely targeted to cellular changes exhibited by individual patients. It can also be a valuable drug development tool for screening new compounds.
To capture the cellular images, the interdisciplinary UB team of biologists, chemists and physicists, led by study co-author Paras N. Prasad, Ph.D., executive director of the UB Institute for Lasers, Photonics and Biophotonics (ILPB) and SUNY Distinguished Professor in the departments of Chemistry, Physics, Electrical Engineering and Medicine, utilized an advanced biophotonic approach that combines coherent anti-Stokes Raman scattering (CARS); two-photon excited fluorescence (TPEF), which images living tissue and cells at deep penetration; and Fluorescence Recovery after Photobleaching to measure dynamics of proteins. The resulting composite image integrates in one picture the information on all four types of biomolecules, with each type of molecule represented by a different color: proteins in red, RNA in green, DNA in blue and lipids in grey.
"This new ability provides us with a dynamic mapping of the transformations occurring in the cell at the molecular level," says Prasad. "It provides us with a very clear visual picture of the dynamics of proteins, DNA, RNA and lipids during the cell's disintegration."
"For the first time, this approach allows us to monitor in a single scan, four different types of images, characterizing the distribution of proteins, DNA, RNA and lipids in the cell," says Aliaksandr V. Kachynski, PhD, research associate professor at the ILPB and co-author.
Before apoptosis was induced, the distribution of proteins was relatively uniform, but once apoptosis develops, nuclear structures disintegrate, the proteins become irregularly distributed and their diffusion rate slows down, says Artem Pliss, Ph.D., research assistant professor at the ILPB and co-author on the paper.
Such precise information will be especially useful for monitoring how specific cancer drugs affect individual cells. "For example, say drug therapy is being administered to a cancer patient; this system will allow for the monitoring of cellular changes throughout the treatment process," notes Kachynski. "Clinicians will be able to determine the optimal conditions to kill a cancer cell for the particular type of disease. An improved understanding of the drug-biomolecule interactions will help discover the optimal treatment doses so as to minimize side effects."
Andrey Kuzmin, Ph.D., research assistant professor at the ILPB and co-author, adds that a new paper from the UB team, forthcoming in Biophysical Journal, further extends this work, which was supported by a grant from the John R. Oishei Foundation of Buffalo, NY.