About half of all brain tumors diagnosed are gliomas. They usually begin in glial cells in the lobes of the upper part of the brain, but they can also grow in other areas, especially cells that surround and support nerve cells near the optic nerve, brain stem and the cerebellum.
Gliomas are tumors that contain a variety of cell types, and the distribution of each cell types varies with each tumor. The most common type of gliomas are astrocytomas. Glioblastoma multiforme, also called GBM or grade IV astrocytoma is the most malignant form of all astrocytomas. It usually occurs in adults and affects the brain more often than the spinal cord.
To diagnose GBM and depending on the patient’s symptoms, a neurologist performs a complete examination, which may include a magnetic resonance imaging (MRI) scan, a computed tomography (CT or CAT) scan or a chest X-ray to determine if the tumor has spread from another part of the body. Usually, an MRI scan finds low-grade astrocytomas earlier than a CT-scan.
Stopping a deadly brain cancer in its tracks
In diagnosing GBM and other brain tumors, molecular imaging technologies are playing an important role by providing a ?window? into the living brain. Where CT and conventional MR imaging provide important structural and anatomic information on the brain, molecular imaging (MI) technologies allow doctors to visualize and measure brain function. However, most molecular imaging techniques suffer from low resolution and difficulty in imaging through the skull.
For the first time, scientists can see pathways to stop a deadly brain cancer in its tracks. Researchers at Case Western Reserve University School of Medicine have imaged individual cancer cells and the routes they travel as the tumor spreads.
The researchers used a novel cryo-imaging technique to obtain the unprecedented look at a mouse model of glioblastoma multiforme, a particularly aggressive cancer that has no treatments to stop it from spreading.
A description of their work, and images, will be published Sept. 1 in the journal Cancer Research.
“We’re able to see things we couldn’t before, and we can use these images to understand how tumor cells invade and disperse,” said Susann M. Brady-Kalnay, a professor of molecular biology and microbiology at the Case Western Reserve School of Medicine, and senior author of the paper. “That information, in turn, can be used to help develop and test the effectiveness of drugs and other therapies used to treat the cancer,” she said.
To obtain the view, the scientists used a model that included four different cell lines of brain cancers at various stages of tumor development and dispersion. The cancer cells were modified with fluorescent markers and implanted in the model’s brain in collaboration with Biomedical Engineering Professor James Basilion’s lab.
The cryo-imaging system, developed by David Wilson, also a professor of biomedical engineering at Case Western Reserve, disassembles the brain layer by layer and reassembles the model into a color three-dimensional digital image.
Using software and algorithms designed by the researchers, they are able to differentiate the main tumor mass, the blood vessels that feed the cancer and dispersing cells. The imaging system enables them to peer at single cells and see exactly where they are in the brain.
LN229 and CNS-1
The researchers found that two cell lines, a human brain cancer LN229, and a rodent cancer CNS-1, best resemble the actions of glioblastoma multiforme in human patients.
Testing new drugs
Reconstructions of models of those two lines enabled the researchers to analyze the extent and patterns of cancer cell migration and dispersal from tumors along blood vessels and white matter tracts within the brain.
The ability to produce such clear and detailed images, the researchers say, will be invaluable when evaluating the potency of drugs and other therapies designed to block dispersal of glioblastoma multiforme cells.
For more information:
Burden-Gulley SM, Qutaish MQ, Sullivant KE, Lu H, Wang J, et al. Novel Cryo-Imaging of the Glioma Tumor MicroenvironmentReveals Migration and Dispersal Pathways in Vivid Three-Dimensional Detail. Cancer Res September 1, 2011 71; 5932 (doi: 10.1158/0008-5472.CAN-11-1553).