In the context of cancer, what happens to cells when HER2 receptors are overexpressed?

When HER2 receptors are overexpressed, cells experience rapid tumor growth due to amplified signaling pathways that promote cell division. HER2 (Human Epidermal growth factor Receptor 2) is a member of the epidermal growth factor receptor family and plays a critical role in the regulation of cell growth and differentiation. Normally, HER2 is present at low levels, but its overexpression leads to increased signaling, which can cause uncontrolled proliferation of cells. This overactive signaling can contribute to the development and progression of certain aggressive types of breast cancer and other malignancies.

This amplified signaling results in enhanced survival and proliferation of the cancer cells. Rather than undergoing normal cellular processes such as apoptosis (programmed cell death) or differentiation into non-dividing cells, these overexpressing cells evade regulatory controls and continue to grow and divide, contributing to tumor growth and cancer development.