ChIP analysis of AR binding on a regulatory enhancer of PSA genes in CRPC cells
ID: 85113 • Letter: C
Question
ChIP analysis of AR binding on a regulatory enhancer of PSA genes in CRPC cells that were treated with lapatinib (and/or DHT) for 4 hours. Use the data below to answer the questions. Why is immunoprecipitation of IgG performed in this experiment? Based on the figure, does inhibiting ErbB2 signaling have any influence on the chromatin binding of the AR protein? Explain your reasoning. What is your predication on the effect of treating AKT inhibitor on AR binding based on both this figure and previous fig Part 3?. Explain your reasoning. The scientists also want to study epigenetic change of PSA-enhancer in response to ErB2 inhibitor treatment in the future. Name two histone modifications that may be associated with PSA enhancer activation.Explanation / Answer
14. The IP with IgG is performed to neglect the background caused by the primary antibodies when pulling down with AR antibody. It will rule out the possibility of an effect of the IgG in the pulling down the specific region of the chromatin.
15. Inhibiting the Erb2 pathway using lapatinib has a significant change in the binding of AR to PSA enhancers compared to only DHT-treated cells. Treating the cells with lapatinib decreases the binding of AR to PSA enhancers.
17. Two of the histone modifications associated with enhancer activation include H3K27Ac and H3K4Me1.