Question

The HER2 gene has been implicated in invasive breast cancers. In those cancers, ________?

1) HER2 has been deleted from both homologous chromosomes.
2) HER2 has been duplicated, sometimes present in hundreds of copies.
3) HER2 has been deleted from one of the chromosomes.

Answer 1

In invasive breast cancers, the HER2 gene is often duplicated, leading to HER2 overexpression. Therapies such as Herceptin and Lapatinib target this overexpression to control tumor growth.

Step-by-step explanation:

The HER2 gene has been implicated in invasive breast cancers. In those cancers, HER2 has been duplicated, sometimes present in hundreds of copies. This gene duplication leads to HER2 overexpression, which is observed in about 20-30 percent of human breast cancer patients. HER2 is a receptor tyrosine kinase involved in cell signaling pathways that regulate cell division.

When overexpressed, HER2 is permanently activated, resulting in unregulated cell division and tumor growth. Therapies such as Herceptin (trastuzumab) and Lapatinib have been developed to specifically target HER2.

Herceptin is a monoclonal antibody that marks HER2 for removal by the immune system and helps to control HER2 signaling. Lapatinib is a drug that inhibits HER2 receptor tyrosine kinase autophosphorylation, reducing tumor growth by interfering with the cell signaling pathway.