SR-BI is a receptor for high-density lipoproteins (HDL) that are commonly referred to as 'good cholesterol' because they help transport cholesterol out of the arteries and back to the liver for excretion.
Previous lab research had revealed that mice fed a high cholesterol diet develop more advanced tumours and their tumours produce more SR-BI.
The research team, including Christiane Danilo, of the Department Stem Cell Biology and Regenerative Medicine at Thomas Jefferson University, and Philippe G Frank, PhD, an assistant professor in the Department of Stem Cell Biology and Regenerative Medicine at Jefferson, manipulated levels of SR-BI in human breast cancer cell lines and examined its effect on tumour formation in a mouse model.
The results of this novel study show that depletion of SR-BI reduces cancer cell and tumour growth, suggesting that it could play an important role in breast cancer," said Dr Frank.
The mechanism of this effect appears to be dependent on endothelial SR-BI and may involve cholesterol efflux as a triggering mechanism (35).
Role of apoA-I, ABCA1, LCAT, and SR-BI in the biogenesis of HDL.
Macrophage ABCA1 and ABCG1, but not SR-BI, promote macrophage reverse cholesterol transport in vivo.