Human epidermal growth factor receptor 2

Human epidermal growth factor receptor 2 (HER2) is a protein that in humans is encoded by the ERBB2 gene. HER2 is a member of the human epidermal growth factor receptor (HER/EGFR/ERBB) family. Amplification or over-expression of this gene has been shown to play an important role in the development and progression of certain aggressive types of breast cancer.

Structure

The HER2 gene is a proto-oncogene located at the long arm of human chromosome 17 (17q12). The protein encoded by this gene is a transmembrane receptor tyrosine kinase. It is a glycoprotein with a molecular weight of approximately 185 kDa containing 1255 amino acids.

Function

HER2 is part of the biological pathway for the transduction of epidermal growth factor (EGF) signals from the cell surface to the nucleus. HER2 has been shown to form heterodimers with other members of the HER family, leading to the activation of several downstream signal transduction pathways.

Clinical significance

In about 30% of breast cancer patients, the HER2 gene is amplified, and the amplified HER2 gene is associated with aggressive disease and poor prognosis. HER2 is also overexpressed in other types of cancer, such as ovarian, stomach, and aggressive forms of uterine cancer.

Treatment

HER2 is the target of the monoclonal antibody trastuzumab (Herceptin), which is used in the treatment of HER2-positive breast cancer. Trastuzumab is an antibody that binds to the HER2 receptor and blocks its function, thereby inhibiting the growth of cancer cells.

See also

• Breast cancer
• Epidermal growth factor
• Trastuzumab

References

Human epidermal growth factor receptor 2 Resources
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