The HER2 Receptor in Breast Cancer
The HER2 gene
What is HER2?
Function
HER2 in breast cancer
What is HER2 gene?
HER2 stands for “Human Epidermal growth factor 2”
It is part of the epidermal growth factor (EGF) family.
The family is made up of four main members: HER-1, HER-2, HER-3, and HER-4, also called ErbB1, ErbB2, ErbB3, and ErbB4
It is located at the long arm of human chromosome 17 (17q12)
It encodes a 185-kDa transmembrane protein.
HER2 is expressed in many tissues and its major role in these tissues is to facilitate excessive/uncontrolled cell growth and tumorigenesis.
HER2 activation
Function
HER2 overexpression in cancer
HER2 overexpression occurs in other forms of cancers also such as stomach, ovary, uterine serous endometrial carcinoma, colon, bladder, lung, uterine cervix, head and neck, and esophagus.
a therapeutic target
HER2 in breast cancer
HER2 is overexpressed in 15–30%of invasive breast cancers.
Breast cancers can have up to 25– 50 copies of the HER2 gene, and up to 40–100-fold increase in HER2 protein resulting in 2 million receptors expressed at the tumor cell surface.
It is associated with a more aggressive disease, higher recurrence rate, and shortened survival.
NF-KB SIGNALING PATHWAY
What is NF-KB?
Nuclear factor kappa-light chain-enhancer of activated B cells
Controls transcription of DNA
It is inactive in most cells
Immune and inflammatory responses, developmental processes, cellular growth and apoptosis
Dysregulation of this transcription factor can thus lead to inflammatory and autoimmune diseases
Activation of NF-KB
structure
It is composed of five related transcription factors: p50, p52, RelA (aka-p65), c-Rel and Rel-B.
NF-KB signaling pathway
classic
alternative
summary