multiplexed ion beam imaging
Posted on by Dr. Francis Collins
The artistic masterpiece above, reminiscent of a stained glass window, is the work of Michael Angelo—no, not the famous 16th Century Italian artist, but a 21st Century physician-scientist who’s out to develop a better way of looking at what’s going on inside solid tumors. Called multiplexed ion beam imaging (MIBI), Angelo’s experimental method may someday give clinicians the power to analyze up to 100 different proteins in a single tumor sample.
In this image, Angelo used MIBI to analyze a human breast tumor sample for nine proteins simultaneously—each protein stained with an antibody tagged with a metal reporter. Six of the nine proteins are illustrated here. The subpopulation of cells that are positive for three proteins often used to guide breast cancer treatment (estrogen receptor a, progesterone receptor, Ki-67) have yellow nuclei, while aqua marks the nuclei of another group of cells that’s positive for only two of the proteins (estrogen receptor a, progesterone receptor). In the membrane and cytoplasmic regions of the cell, red indicates actin, blue indicates vimentin, which is a protein associated with highly aggressive tumors, and the green is E-cadherin, which is expressed at lower levels in rapidly growing tumors than in less aggressive ones. Taken together, such “multi-dimensional” information on the types and amounts of proteins in a patient’s tumor sample may give oncologists a clearer idea of how quickly that tumor is growing and which types of treatments may work best for that particular patient. It also shows dramatically how much heterogeneity is present in a group of breast cancer cells that would have appeared identical by less sophisticated methods.