Thursday December 1  was the beginning of the 3rd phase of Sam’s leukemia clinical trial protocol called continuation. This phase lasts 100+ weeks so it’s a marathon within a marathon. He got a bone marrow biopsy as well as 3 doses of medicine: doxorubicin, PEG-aspariginase, and vincristine. All are heavy hitters so Friday he felt understandably crappy.  Also Saturday but somewhat less so.  The evenings (from 5-7:30 pm) seem to be down times. And he’s eating more at night now too, after waking up from his 2 hour evening nap.

I looked up more details about each of the 3 medicines: PEG asparaginase (derived from E. Coli bacteria) breaks down the amino acid asparagine. Intracellular asparagine levels regulate uptake of amino acids into the cell, so if there is no asparagine, cancer cells can’t synthesize proteins (of course, Sam’s healthy cells also need asparagine). Cancer cells appear to have a higher demand for asparagine, and this demand is what the medicine is exploiting (https://www.nature.com/articles/ncomms11457). Vincristine disrupts cell division by blocking the tubular protein that allows the chromosomes to separate during metaphase (remember the phases of cell division from Bio I: Interphase, Prophase, Metaphase, Anaphase, and Telophase). It can be obtained from the Madagascar periwinkle Catharanthus roseus. Doxorubicin is a DNA intercalator which means it binds to the DNA during replication and inhibits cell division (is more likely to affect rapidly multiplying cells like cancer cells but also hair cells, hence the hair loss that many cancer warriors have).  Doxorubicin is derived from streptomyces bacterium.

So how’s that for a biology lesson for today. Don’t you feel smarter now? 🤓You’re welcome 💪🏼

Sam's a true warrior as are all people fighting cancer. It’s a beast and the medicines are too. The only way is through. 

#FULeukemia

#TeamSam