Protein that cuts malignancy of breast cancer discovered

23 april 2008--Researchers have discovered a protein which can reduce the malignancy of breast cancer tumors and also predict whether the cancer will metastasize, according to a study published Monday.
"This protein seems to be suppressing tumor growth," said study author Kent Hunter of the National Cancer Institute outside of Washington.
In studies on mice and in gene expression profiles of human cancer cells, Hunter and his team found that they could dramatically slow the growth of breast cancer tumors and prevent the cancer from spreading.
They did this by inserting extra copies of the gene that expresses the protein into the tumor, according to the study published in the Proceedings of the National Academy of Sciences.
While those tumors were not eliminated, they grew to one tenth of the size of those which had not been stimulated to overproduce the protein.
They also had molecular profiles of significantly less malignant tumors and did not spread.
"What we're interested in is looking at how this would be induced by other means... to find a drug that would turn this gene on in tumors," Hunter said. "That would reduce the malignancy of the tumor and prolong survival."
In the meantime, the presence, or lack thereof, of this protein could be used to predict which patients are at risk of metastasis, he said.
"We could hopefully spare those patients who will not benefit the rigors associated with adjuvant therapy," he explained.
While there are at least two gene expression profiles currently in clinical trials to test the risk of metastasis, researchers have not yet teased out the root cause of those gene expressions.
"We know what the root cause of this gene expression change: that is this protein," Hunter told AFP.
"That gives us a handle on how we can investigate what is causing all these particular gene expression signatures and allows us potentially to do molecular targeting down the line that might somehow affect the cancer."
Any type of clinical application is still far away, he cautioned.