Eps8, a cancer-causing adaptor protein that facilitates proliferation of colorectal and cervical cancer cells, could become a new target for treatment of the two types of cancer, a researcher at National Cheng Kung University in Tainan City said Wednesday. Eps8, which stands for 'EGF receptor pathway substrate number 8,' was first discovered in the 1990s but its role in cancer formation was unknown at the time, according to Leu Tzeng-horng, head of the southern Taiwan university's Institute of Pharmacology. In 2007, a research team headed by Leu linked Eps8 to colorectal cancer, and it confirmed a year later that it was also associated with cervical cancer. Eps8 is an adaptor protein and a common substrate for both epidermal growth factor (EGF) receptor and the enzyme Src tyrosine kinase. Src not only can phosphorylate, or 'activate' Eps8, but also influence its expression, Leu explained. The team's latest study found that Eps8, in turn, can spur the Src substrate focal adhesion kinase (FAK) , which is also associated with the progression of colorectal cancer. Through Eps8's role in this chain, its involvement in colon tumor formation and progression was confirmed. In experiments performed on animals, the team observed that lowering Eps8 resulted in decreased tumor growth of cancer cells, suggesting that reducing Eps8 could therefore inhibit the proliferation of cancerous cells. Citing analyses of cancer specimens, Leu noted that excessively high levels of Eps8 were seen in late-stage colorectal cancer patients, while patients with thyroid cancer, breast cancer and cervical cancer were found to have higher- than-normal levels of Eps8. Leu said that in the future, agents that attenuate Eps8 can be used to inhibit or annihilate tumor growth of cancer cells, but their effectiveness will have to be tested through medical experiments on people. 