Question

Estrogen is a steroid hormone that has been shown to stimulate cell proliferation in some forms of breast cancer. Imagine you work in a research lab that wants to identify direct gene targets of the estrogen signaling in breast cancer cells. Which experimental method could you use to identify regulatory elements that are bound by the estrogen receptor?

A)PCR
B)Western Blot
C)Immunostaining
D)Bisulfite Mapping
E)Chromatin Immunoprecipitation (ChIP)

Answer 1

Chromatin Immunoprecipitation (ChIP) is the best method to identify regulatory elements that are bound by the estrogen receptor in breast cancer cells, as it isolates specific DNA sequences that interact with the protein.

Step-by-step explanation:

To identify direct gene targets of the estrogen signaling in breast cancer cells, the experimental method that could be used is Chromatin Immunoprecipitation (ChIP). ChIP enables the determination of the specific location on DNA where the estrogen receptor or any other protein of interest is bound. This method involves cross-linking proteins to DNA, fragmenting the DNA, and immunoprecipitation using an antibody to the protein of interest (such as the estrogen receptor). The precipitated DNA-protein complexes are then purified, the cross-links are reversed, and the DNA is analyzed by PCR, sequencing, or microarrays to identify the binding sequences.