The APS played a key role in the research. The particular APS beamline Finney and her colleagues used employs specialized optics to focus coherent X-rays to sub-micrometer spot sizes, through which the sample is raster scanned (scanning from side to side, top to bottom). By collecting emitted fluorescence spectra at each point using an energy-dispersive detector, the researchers obtained images displaying the concentration and spatial distribution of many elements, including phosphorous, sulfur, iron, copper and zinc. Overlaying these elemental maps onto optical images of the cells, Finney and her colleagues then correlated elemental content with cellular structures.
"Our findings were very clear," said Finney. "We observed a dramatic relocalization of between 80 and 90 percent of cellular copper to the tips of the tendril-like projections angiogenic cells send out between one another and across the cellular membrane within the first two hours." Copper did, indeed, appear to play a special role in angiogenesis, at least on the basis of this observation.
To extend these studies to a living organism, Finney and her colleagues then examined sections of breast tumor tissue that were rich in newly formed blood vessels. "Once again," said Finney, "we found that in contrast to both non-vascularized areas and areas of mature blood vessels, in areas of tissue where blood vessels were newly invading surrounding tissue, the cells showed copper localized at the periphery of the cells and in areas immediately outside of any apparent cellular structures."
What are the implications of this discovery?
According to Finney, "These findin
Source:DOE/Argonne National Laboratory