Low levels of an iron-regulating protein are linked to the most aggressive and recurring cancers, according to a study published in the journal Science Translational Medicine (2010 Aug 4;2(43):43ra56).
To begin the study, researchers at Wake Forest University Baptist Medical Center (WFUBMC) looked at isolated human breast cancer cells and found that there was a significant reduction of ferroportin in the cancerous cells compared to normal breast cells. Then researchers artificially increased ferroportin to near normal levels in an aggressive breast cancer cell line to determine whether the reduction in ferroportin in cancer cells directly contributes to cancer growth. Using a mouse model, the researchers watched the growth of tumors formed by these cells, and reported that the ones in which the levels of ferroportin had been restored to normal grew more slowly than the tumors formed by cells with depleted levels of the protein.
As researchers continued their study, they looked at ferroportin levels in human breast cancer tissue and found that ferroportin levels were lowest in the most aggressive areas of cancer, confirming that the relationship dose not only occurs in cell cultures and isolated breast cancer cells but also in the actual tissue of women with cancer.
Finally, researchers explored four large study databases of breast cancer patients to determine if ferroportin levels in human breast cancer were associated with long-term outcomes.
“Uniformly, we found that ferroportin levels were a strong predictor of the propensity for a woman’s breast cancer to recur,” said Frank Torti, MD, MPH, director of the Comprehensive Cancer Center at WFUBMC, senior author on the paper, and co-lead investigator for the study. “It’s a striking prediction. This marker separates women into good and poor prognostic groups independently from any other factors such as tumor size, grade, lymph node status, or other condition.”