P53 in Cancer

Nicole Gilbert

P53 is arguably the most impactful protein in all of cancer. It appears in half of all tumors, and recent studies show that it may be a leading factor for a cure. Known as “The Guardian of the Genome,” it has the potential to destroy or save entire organisms from cancer.


What is P53?

P53 is a protein that has numerous different functions involving DNA damage. Firstly, it attaches itself to a piece of DNA and scans it to see how much damage the DNA has. Then it goes on to signal many different repair enzymes to fix these mistakes in DNA. The second function that P53 has is to send cells into apoptosis. This will only occur if the DNA damage is so overwhelming that the repair enzymes can’t fix it anymore. If this occurs, P53 will send out signals to other proteins that will activate apoptosis. The final function of P53 is to pause the cell cycle if the DNA isn’t correct. This is done during the G1/S phase checkpoint. While the cell cycle is paused the DNA will usually be repaired by other enzymes.


How is it involved in cancer?

P53 plays a major role in cancer because it has the power to prevent or cause tumors. When P53 functions properly, it fixes DNA damage or mutations. If the damage is extensive it may even kill the cells. This blocks cancer because the mistakes are being fixed and the cells will all have correctly functioning proteins. But, if P53 has a loss of function mutation then it can no longer prevent these mutated genes and cells from continuing through the cell cycle and proliferating (growing/dividing). This means that cells have the capability to completely change into cells that would result in tumors. For example if P53 was functioning correctly and the ras protein’s gene was mutated, it would either be repaired, or the cell itself would be destroyed. But if the P53 protein had a loss of function mutation, then the ras protein would never be fixed and the cell would grow and divide with that mutation leading to numerous problems, including cancer.


What are researchers doing?

Researchers have made huge amounts of progress learning about P53 and trying to find a cure. P53 was only discovered in 1979 and from then on scientists have made massive discoveries. For example until very recently, there was no way of looking clearly at p53 through any type of imaging tool because of its size and floppiness. But Rommie Amaro used the power of supercomputers to finally create a video of them. Now, people are able to see the actions of P53 much clearer. Although there are many subsections to the topic of P53, the main focus is on a cure. Some drug researchers are working binds to the DNA and fixes P53’s shape which in turn makes it function correctly. Another drug upregulates the expression of P53 in hopes that some of the proteins would be properly functioning and therefore would do their job. But overall this topic still has major progress to be made.


By Joe Beatty ’19



Service, Robert F. “This Protein Is Mutated in Half of All Cancers. New Drugs Aim to Fix It before It’s Too Late.” Science. American Association for the Advancement of Science, 16 Nov. 2016. Web. <http://www.sciencemag.org/news/2016/10/protein-mutated-half-all-cancers-new-drugs-aim-fix-it-it-s-too-late>.

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