How does trastuzumab control cell growth in breast cancer?

Trastuzumab is a targeted therapy specifically designed to inhibit the action of the HER-2 protein, which is overexpressed in some breast cancer cells. HER-2 (Human Epidermal growth factor Receptor 2) is a receptor that, when activated, promotes cell division and growth. By binding to this receptor, trastuzumab blocks the signaling pathways that would normally encourage tumor cell proliferation, leading to slowed growth or death of these cancerous cells.

The specificity of trastuzumab for HER-2 is crucial as it allows for a more targeted approach to treatment, minimizing effects on normal cells and reducing potential side effects compared to traditional chemotherapies. This mechanism is fundamental for its effectiveness in treating HER-2 positive breast cancers, making it a cornerstone therapy for patients whose tumors exhibit this particular protein overexpression.