Cancer drugs of the new, molecular generation destroy malignant breast tumors in a targeted manner: They block characteristic molecules on tumor cells - receptors for the hormones estrogen or progesterone, or a co-receptor, called HER2, that binds to many growth factors. But about one in every six breast tumors has none of these receptors. Such cancers, called triple-negative, are particularly aggressive and notoriously difficult to treat.
Some of these therapy-resistant cancers have a potential molecular target for cancer drugs, a growth-factor receptor called EGFR, but an EGFR-blocking drug has proved ineffective in treating them. In a study published recently in the Proceedings of the National Academy of Sciences, Weizmann Institute researchers propose a potential solution: to simultaneously treat triple-negative breast cancer with two EGFR-blocking antibodies instead of one. In a study in mice, the scientists showed that a certain combination of two antibodies indeed prevented the growth and spread of triple-negative tumors. The research team, led by Prof. Yosef Yarden of the Biological Regulation Department and Prof. Michael Sela of the Immunology Department, included Drs. Daniela Ferraro, Nade`ge Gaborit, Ruth Maron, Hadas Cohen-Dvashi, Ziv Porat, Fresia Pareja, and Sara Lavi, Dr. Moshit Lindzen and Nir Ben-Chetrit.