Breaking Bad's Cancer

I’m sure many of you have at least heard of AMC’s hit show Breaking Bad. The show follows the story of Walter White, a high school chemistry teacher who was diagnosed with terminal lung cancer. In order to leave his family in a financially stable state when he dies, Walt starts synthesizing methamphetamine. Later on in the show, he starts his chemotherapy treatment. So, what exactly is chemotherapy?
Chemotherapy, generally, is a term for a treatment of any physical ailment with chemicals or drugs. Now, however, the term is almost always used to describe cancer treatment specifically.  Before we can outline and understand the treatment given to Walt, we need to understand lung cancer. Lung cancer is just that, cancer that starts in the lungs. It is an uncontrolled cellular growth in the lungs. There is a mishap in the cellular signaling that sends the cells on a division spree. This is caused by a mutation in epidermal growth factor receptors (EGFR). These receptors regulate the cell cycle, meaning it controls division, proliferation, and apoptosis of the cell. It can also be caused by mutations in the p53, tumor suppressor gene found on chromosome 17. (A great paper on lung cancer progression can be found here)
Now back to the question before, what is chemotherapy in the context of lung cancer?
The most common drugs used in treatment are cisplatin and carboplatin. Cisplatin works in a very interesting way. It crosses into the nucleus and interferes with DNA. It prefers to bond to guanine out of the bases. By binding to the guanine, it can cause crosslinking in DNA. This calls in DNA repair mechanisms, which in turn causes apoptosis to occur. Pretty cool stuff.
Carboplatin works in much the same way, but it just has a different chemical structure than cisplatin. It also has reduced side effects. Nausea and vomiting are not as severe and are easily controlled. It is also less toxic to the kidneys.
So, there you have it, now you can understand a little bit of what exactly Walt is going through when he receives his treatment. He may be on cisplatin with the way he throws up so often, but we won’t know for sure unless the show tells us! Thanks for reading.