Study finds blood-brain barrier can slow tumor growth by limiting nutrients

MELBOURNE, Nov. 24 (Xinhua) -- Scientists have uncovered how the brain's protective barrier can slow the growth of brain tumors by controlling their access to nutrients, pointing to potential new targets for therapy.

The study has found how the glial cells that form the brain's protective barrier can act as "gatekeepers" and slow down the growth of some brain tumors, according to a statement of Australia's Peter MacCallum Cancer Center on Monday.

Cancer cells need constant nutrients, such as sugars for energy, amino acids to build proteins, and fats for structure and support, to grow, making them vulnerable when nutrients are scarce, said the study highlighting how the tumor environment shapes cancer growth.

Published in PLoS (Public Library of Science) Biology, the study found that a brain tumor's response to nutrient restriction is controlled by the blood-brain barrier -- a layer of glial cells that protects the brain and regulates the flow of nutrients.

The surrounding glial cells which act like gatekeepers "influence how many nutrients reach the tumor, and this directly affects how the cancer behaves under nutrient-poor conditions," said Peter Mac Professor Louise Cheng, who led the study.

Cheng's team, in collaboration with scientists from Japan and Britain, discovered that a key protein called Path, which transports amino acids into the brain, behaves differently in healthy and tumor-affected glial cells.

Healthy glial cells increase Path levels when nutrients are low, but tumor-affected glial cells decrease Path levels, disrupting their function and slowing tumor growth by limiting the tumor's ability to divide, according to Cheng.

"This tells us that Path is a critical switch," she said, adding its levels at the blood-brain barrier determine how sensitive tumors are to changes in nutrient availability. Enditem