question about her2

[CoachPlayWin]

Hi Ladies,
I read here everyday, and have learned so much. Thank you for all that you do. A quick question about Her2...is there a difference between over-expression and amplification? I have seen both descriptions in the literature, but not sure if they are the same, or not, and what the impact would be on treatment, etc.

Thanks!

[Lani]

whether the gene product (the receptor itself) is present in excessive numbers. (I think I mistyped in the subject line--by the former I am referring to gene amplficationk, by the latter to her2receptor overexpression.

Think of the gene as being the recipe book instructions on how to make the receptor, its product.


It is the latter, the receptor, being present in excessive amounts which causes the the excessive signalling which causes her2+ breast cancer to grow more quickly, metastasize more readily and widely and act more aggressively than her2- breast cancer.

For example...from a recent paper: "Amplification of the human epidermal growth factor receptor type 2 (HER2, also called HER2/neu) gene and overexpression of its product in breast-cancer cells may be associated with responsiveness to anthracycline-containing chemotherapy regimens"


If you watch the SABCS presentation I recommended a couple of days ago, there are nice illustrations of what the receptor looks like and what it does.

Hope this helps.