Findings from Fox Chase Cancer Center suggest doctors could one day block the protein's effects to boost the ability of drugs to kill tumors
Blocking a specific protein renders tumors more vulnerable to treatment in mice, suggesting new therapies could eventually achieve the same in humans, according to new research from Fox Chase Cancer Center to be presented at the 2012 CTRC-AACR San Antonio Breast Cancer Symposium on Friday, December 7, 2012.
"Hopefully, with further testing, this research could one day result in a new therapy that blocks the effect of this protein and, in turn, boosts the effects of cancer drugs," says study author Elizabeth Hopper-Borge, PhD, Assistant Professor at Fox Chase.
The protein in question is a type of ATP-binding cassette drug efflux pumps, known more simply as ABC proteins. These proteins sit on the membranes of cells, where they act just like pumps-removing cancer drugs from the cell, thereby making them less effective. The body contains close to 50 such proteins, explains Hopper-Borge, but only 3 appear capable of evading the effects of cancer drugs, including common types used to treat lung, ovarian, and breast cancers.
The current research, supported by the National Institutes of Health, focuses on the protein ABCC10, which has not been studied in as much detail as some other ABC proteins, says Hopper-Borge. Last year, she and her colleagues found that mice lacking ABCC10 experienced physiological changes after taking a cancer drug, suggesting the drug was having an effect.
As part of the latest project, the authors performed a similar experiment in mice engineered to develop breast cancer. They found that, 21 days after exposure to a cancer drug, the tumors that lacked ABCC10 were much smaller than the tumors that still carried the protein. "This is probably the first time it's been shown that removing this protein helps sensitize tumors to cancer drugs," says Hopper-Borge.