Breast cancer cells masquerade as neurons, allowing them to hide from the immune system, cross the blood-brain barrier and begin to form ultimately-deadly brain tumors, the researchers found.
“The most dreaded location for cancer to spread is the brain,” said Rahul Jandial, a City of Hope neurosurgeon who led the study, available online and slated for print publication in the Proceedings of the National Academy of Sciences in February. “As we have become better at keeping cancer at bay with drugs such as Herceptin, women are fortunately living longer. In this hard-fought life extension, brain metastastes are being unmasked as the next battleground for extending the lives of women with breast cancer.”
Jandial and other City of Hope scientists wanted to explore how breast cancer cells cross the blood-brain barrier — a separation of the blood circulating in the body from fluid in the brain — without being destroyed by the immune system.
“If, by chance, a malignant breast cancer cell swimming in the bloodstream crossed into the brain, how would it survive in a completely new, foreign habitat?”Jandial said. Jandial and his team’s hypothesis: Given that the brain is rich in many brain-specific types of chemicals and proteins, perhaps breast cancer cells exploit these resources by assuming similar properties. These cancer cells could potentially deceive the immune system by blending in with the neurons, neurotransmitters, other types of proteins, cells and chemicals.
The Study: Taking samples from brain tumors resulting from breast cancer, Jandial and his team found that the breast cancer cells were using the brain’s most abundant chemical as a fuel source. This chemical, GABA, is a neurotransmitter used for communication between neurons. When compared to cells from non-metastatic breast cancer, the metastasized cells expressed a receptor for GABA, as well as for a protein that draws the transmitter into cells. This allowed the cancer cells to essentially masquerade as neurons. Jandial offers:
“Breast cancer cells can be cellular chameleons (or masquerade as neurons) and spread to the brain.”
He says that further study is required to better understand the mechanisms that allow the cancer cells to achieve this disguise. He hopes that ultimately, unmasking these disguised invaders will result in new therapies. I’m Dr. Michael Hunter.
The small print: The material presented herein is informational only, and is not designed to provide specific guidance for an individual. Please check with a valued health care provider with any questions or concerns. As for me, I am a Harvard- , Yale- and UPenn-educated radiation oncologist, and I practice in the Seattle, WA (USA) area. I feel genuinely privileged to be able to share with you. If you enjoyed today’s offering, please consider clicking the follow button at the bottom of this page.
Available now: Understand Colon Cancer in 60 Minutes; Understand Brain Glioma in 60 Minutes. Both can be found at the Apple Ibooks store. Coming Soon for iPad: Understand Breast Cancer in 60 Minutes; Understand Colon Cancer in 60 Minute; Understand Colon Cancer in 60 Minutes; Understand Brain Glioma in 60 Minutes. Thank you.
Reference: J. Neman, J. Termini, S. Wilczynski, N. Vaidehi, C. Choy, C. M. Kowolik, H. Li, A. C. Hambrecht, E. Roberts, R. Jandial.Human breast cancer metastases to the brain display GABAergic properties in the neural niche. Proceedings of the National Academy of Sciences, 2014; DOI:10.1073/pnas.1322098111