You are studying the EGFR signaling pathway in a tumor cell line… 1 answer below »

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Choose one of the following. You may work individually or as a group of two. There will be a folder on Da to upload your file into, due one hour before your final.

1. You are studying the EGFR signaling pathway in a tumor cell line isolated from a melanoma. These cells have uncontrolled proliferation. They continue to grow in the absence of EGF or any other growth factor. Another group determined this was due to constitutive activation of the Ras-MAP kinases pathway.

A. You compare the levels of EGFR to wild type cells and see no difference. How would you experimentally compare EGFR levels? What could account for this difference in proliferation but not in overall receptor protein levels?

B. You hypothesize that the Raf kinase may be constitutively active. You are given purified MEK protein. How could you test the state of kinase activation in these cells?

C. You hypothesize that either Ras or MAK kinase must be constitutively active. Design experiments to prove which hypothesis is correct.

2. Human papillomaviruses (HPVs) are a family of DNA viruses that cause genital warts. HPVs have been predominantly associated with cervical cancer. One of the proteins encoded by the HPV virus is E5. E5 is a short transmembrane protein that forms a dimer or trimer.

A. E5 can form a stable complex with endogenous host PDGF receptor. Explain how this could lead to cell transformation.

HPV also encodes proteins E6 and E7. It has been shown that adding E6 and E7 to normal cells is sufficient to transform them and induce uncontrolled mitosis. Initially, it was not clear how E6 and E7 accomplished this, but recently it has been demonstrated that E6 binds and inhibits p53, while E7 is known to bind and inhibit Rb.

B. Explain how these findings show how HPV causes warts (which are benign tumors).

C. How does HPV infection increases one’s risk of developing_ cancer?

3. You have a mouse strain that is predisposed to developing skin cancer. Based on the literature in the cancer field, you come up with a list of 10 potential candidate genes that might be mutated in these mice. You are convinced that the mice of this strain must harbor one of these mutations.

A. Design an experiment to determine which candidate gene from the list was actually mutated in this mouse. You may not use DNA sequencing.

B. When you do the experiment, do you need to take tissue samples from the tumor itself, or can you take tissue from anywhere in the mouse? Why?


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