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By Kathryn Warden
U of S researchers are seeing cancer cells under a new light – synchrotron light.
Cell biologist Bernard Juurlink used to think the synchrotron was just a tool for physicists and material scientists. But after coming out to workshops, he’s begun to use synchrotron light in his own cancer and stroke research.
“The technology is so new and unexplored in respect to its potential that even a neophyte can come up with useful ideas,” he told more than 130 participants at a campus workshop last weekend on synchrotron applications in the life sciences.
“I’ve become very excited about synchrotron medical imaging.”
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| Bernard Juurlink |
Along with neurosurgeons Bob Griebel and Suzanne Hattingh, post-doctoral fellow Huse Kamencic and clinical research fellow Elisabeth Schultke, Juurlink is working on a project that could lead to improved survival rates for patients with highly malignant brain tumors called glioblastomas. (Funding is from the Health Services Utilization and Research Commission and the Royal University Hospital Foundation.)
The median survival rate for patients with this often inoperable class of brain cancers is only nine months.
Schultke was recently sent to a synchrotron in Daresbury, England to collect diffraction patterns from tumor tissue samples taken from glioblastoma patients. Working with Daresbury’s Rob Lewis, she found minute structural differences that couldn’t be detected with conventional techniques. Her data will be correlated with lab reports and information on patient outcomes to help determine why some patients treated with radiation or chemotherapy survive longer than others.
Ideally, scientists would like to develop a non-invasive treatment for these deadly brain tumors – one that would target the cancer cells and spare the surrounding tissue.
That’s the focus of synchrotron-based studies by Gelsomina (better known by her nickname “Pupa”) De Stasio, a University of Wisconsin-Madison physics professor. Her team is exploring a new way to destroy glioblastoma cancer cells and spare healthy brain cells.
The idea is to target cancer cells with a gadolinium compound and then bombard the skull with thermal neutrons – low-energy particles that deliver almost no radiation. She has likened this two-step treatment, which has not yet been tried on humans or animals, to “making a microscopic nuclear bomb explode in each cancer cell.”
Of course, this approach works only if the gadolinium can be selectively absorbed by the tumor cell nuclei and not by nearby healthy tissue. Previously it had been assumed that gadolinium did not reach the cell nuclei. But in a study published last year in Cancer Research, she and her team showed that gadolinium (a contrast agent used in MRI scans to get detailed pictures of brain tumors) penetrates the cell membrane and is concentrated in the cell nuclei.
The team also was able to use synchrotron light to determine which gadolinium compounds are most readily absorbed by tumor cells in culture. They’ve found that two gadolinium compounds have a greater than 90-per-cent uptake by cancer cell nuclei.
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| Gelsomina De Stasio |
De Stasio cautions that the work is “far from being a therapeutic technique,” adding she’s got another five years’ work before she’ll know whether this potential therapy can proceed to human trials.
She’s also been examining “the oldest thing we know of on Earth” – a tiny, 4.4-billion-year-old grain of sand from Western Australia that colleague John Valley discovered. It may hold clues to the type of surrounding rock that existed when the zircon crystal formed.
De Stasio is a native of Rome and her accomplishments were recognized last year by the president of Italy when he named her “Cavaliere della Repubblica” or “Official Knight of the Italian Republic.”
Other workshop speakers described cutting-edge synchrotron science that could have implications for diseases ranging from Alzheimer’s to osteoporosis.
For example, Helen Nichol, who will join the U of S department of anatomy and cell biology this fall, is studying iron deposits in mitochondria, the energy-producing compartments within cells. Iron-storing proteins have been associated with diseases such as Parkinson’s, multiple sclerosis, sideroblastic anemia and Friedriech’s Ataxia, a debilitating neurological disease.
In particular, Nichol is looking at iron-containing cells in the guts of fruit flies. She is currently a Visiting Scholar at the Stanford synchrotron, a training opportunity created for her by the U of S and the Saskatchewan government.
In one of the more unusual life sciences applications, researcher Lisa Miller of the Brookhaven National Laboratory in Upton, New York is using synchrotron light to study how bleaching and coloring affect hair structure – research of interest to the hair products industry.
Workshop participants were invited to get started on synchrotron work by using the Canadian beamlines at the University of Wisconsin or by making use of an arrangement with the Brookhaven facility where 20 per cent of the time on a particular beamline is available to Canadian Light Source users.
Juurlink has already taken advantage of the latter opportunity by collaborating with Kathy Gough of the University of Manitoba to analyze tissue samples related to his research into the role of diet in stroke prevention.
He describes the international synchrotron science community as “a friendly community that’s eager to embrace researchers new to this technology.”
