Options for treatment are limited when cancer spreads to the brain. The majority of medications made to fight metastases either cannot penetrate the blood-brain barrier or are ineffective against brain metastases.

"Understanding how cancer cells thrive or fail in the brain niche could help us develop new treatments targeting these molecular processes," said Sofia Merajver, M.D., PhD, the Greater Good Breast Cancer Research Professor at the University of Michigan Rogel Cancer Center.

Merajver and colleagues used two microfluidic chips to record cancer cell migration to the brain and examine what was occurring in the blood-brain niche in order to comprehend the molecular mechanisms that affect how cancer cells pass through the blood-brain barrier. The journal Advanced NanoBiomed Research publishes the findings.

Using breast cancer cell lines, they found that Dkk-1, a cytokine released by the astrocytes, triggers the cancer cells to migrate. Dkk-1 is known to play a role in Wnt signalling, a key signalling pathway linked to cancer progression.

"Crosstalk between brain niche cells and cancer cells allows invading cancer cells to permeate the blood-brain barrier. Reducing Dkk-1 levels near invading tumour cells might disrupt this crosstalk and prevent brain metastases," said corresponding author Christopher R. Oliver, PhD, a post-doctoral fellow in the Merajver Lab.