What is the HER2 pathway?
HER2 is a membrane tyrosine kinase and oncogene that is overexpressed and gene amplified in about 20% of breast cancers. When activated it provides the cell with potent proliferative and anti-apoptosis signals and it is the major driver of tumor development and progression for this subset of breast cancer.
What is the significance of HER2/neu over expression on the breast cancer Signalling pathway?
When HER2 is overexpressed multiple HER2 heterodimers are formed and cell signaling is stronger, resulting in enhanced responsiveness to growth factors and malignant growth. This explains why HER2 overexpression is an indicator of poor prognosis in breast tumors and may be predictive of response to treatment.
What is HER2/neu and what does it encode?
HER2/neu holds the greatest promise as a single biomarker that has both prognostic and predictive value. The human HER2 gene is located on chromosome 17 and encodes the transmembrane protein p185 with structural homology to the epidermal growth factor receptor.
What binds to HER2 receptor?
Trastuzumab as such is a humanized monoclonal antibody that targets the ECD of HER2. It acts by binding to the extracellular domain of HER2 and exhibits therapeutic efficacy in HER2 over-expressing metastatic and early stage breast cancer [94–95].
Where is HER2 normally expressed?
HER2 is normally expressed on cell membranes of epithelial cells of several organs like the breast and the skin, as well as gastrointestinal, respiratory, reproductive, and urinary tract [17].
Is chemo necessary for HER2 positive?
Trastuzumab and chemotherapy are even recommended for women with very small, HER2-positive breast cancers. Tumors as small as 0.5 cm often warrant such treatment. However, decisions must be individualized based on your own individual risk.
What is the function of HER2 neu?
The HER2 gene makes HER2 proteins (also sometimes referred to as HER2/neu proteins). HER2 proteins are receptors on breast cells. Normally, HER2 receptors help control how a healthy breast cell grows, divides, and repairs itself.
What type of receptor is HER2?
HER2 belongs to the human epidermal growth factor receptor family, which includes EGFR (alias HER1), HER3, and HER4. HER2 works as an oncogene in several cancers including breast cancers, manifesting its effect of carcinogenesis mainly by overexpression or due to gene amplification.
What is HER2 negative mean?
HER2-negative breast cancer means tests show no abnormality in the human epidermal growth factor receptor 2 gene. Normally present in breast tissue, HER2 receptors help control how breast cells grow and divide. When the gene stops functioning properly, breast cells begin to multiply in an uncontrolled way, states Breastcancer.org.
Is HER2 negative good?
HER2 is a protein that helps breast cancer cells grow quickly. Breast cancer cells with higher than normal levels of HER2 are called HER2-positive. These cancers tend to grow and spread faster than breast cancers that are HER2-negative, but are much more likely to respond to treatment with drugs that target the HER2 protein.
Is HER2 cancer aggressive?
HER2 protein overexpression may occur as a result of HER2 gene amplification and is often associated with aggressive disease and poor prognosis in breast cancer. 6 Approximately one in five cases of breast cancer are considered HER2 positive. The current
What is HER2 negative breast cancer prognosis?
When a breast cancer is HER2-negative, it means that the cancerous cells do not contain high levels of the protein HER2. There are many treatment options available for this type of breast cancer