Video from tecknowledge2000 explaining how Herceptin works

Herceptin a multi-modal approach targeting HER2-positive breast cancer

For some women effective treatment of breast cancer can start deep at the root of the disease, some of the most aggressive breast cancers are driven by a transmembrane receptor protein known as HER2, a member of the HER family of receptor tyrosine kinases, roughly 20,000 HER2 receptors are typically expressed on the surface of healthy breast cells. In approximately twenty-five percent of primary breast cancers the HER2 protein is overexpressed resulting in tumor cells with as many as two million receptors present on the surface of each cell. These cancers are called HER2 positive. The effect of HER2 overexpression is a tremendous increase in receptor-mediated intracellular signaling, directing the cell to proliferate uncontrollably. For this reason HER2 driven disease results in an aggressive form of breast cancer which if left untreated can progress rapidly.Herceptin is a monoclonal antibody, specifically designed to target the HER2receptor with an extended half-life that allows for constant exposure to tumor cells. Based on preclinical studies, Herceptin delivers continuous inhibition of HER2 activity by working on both the extracellular and intracellular domains of the receptor. Herceptin is the only approved therapy designed to bind to HER2 positive tumor cells extracellularly and flag them for destruction by the immune system. In addition bound Herceptin prevents HER2 receptor activity by blocking intercellular HER2 signaling and ultimately inhibiting cell proliferation along with its direct effects on theher2 receptor. Based on preclinical studies Herceptin enhances the effects of chemotherapy leading to cell stasis and death with several distinct mechanisms. Herceptin works both extracellularly and intracellularly to deliver a multi-modal attack against cells overexpressing HER2 receptor, a receptor linked to one of the most aggressive forms of breast cancer