Re-Blogging something I found yesterday which helps explain small arm 17p deletion; the chromosomal mutation I have which makes my CLL more sinister. Dr Sharman helps explain it well and explains why traditional chemotherapy regimens like FCR (Fludarabine,Cyclophosphamide & Rituxan) for CLL generally don’t work well for patients w/ 17p deletion.. Thanksfully, Ibrutinib is well on its way to approval by the FDA and the trial drug I am taking (ipi-145) also seems to be working for me. Here’s a snippet of his post. You can read his full post via Dr. Sharman’s CLL & Lymphoma Blog
When we say 17p deletion CLL, what we mean is that the short (petit) arm of chromosome 17 is missing. You have 23 pairs of chromosomes (46 total) and as you get higher in the numbering, the chromosomes get smaller and smaller. It is probably an excessive simplification to say that the biology of 17p is all about one particular protein called p53 – but for the time being that is most of the story.
P53 is affectionately called “the guardian of the genome.” Every time I read about p53 I discover some new function of the protein that I didn’t know about before. It has a tremendous number of different functions. One of the most important though is that it will bind to DNA in a bunch of places and turn on / off the genes at those locations. In this role it is known as a “transcription factor.” Many of the proteins that are regulated by p53 have to do with cell survival or cell death. When P53 decides it is time for a cell to die – very few things can stop that. The most important signal that turns on p53 is DNA damage (hence – guardian of the genome).