Cancer is basically like a bunch of immigrants that invade your body and keep multiplying until it’s not your damn country anymore. I know, I know, sorry, whatever.
In cancer, cell-division goes apeshit. In a broad simplification,
Proto-Oncogenes = Cell Division On
Tumor-Suppressor Genes = Cell Division Off
If either of these genes gets fucked up then the cells divide out of control and you get cancerous growth. I recommend watching this short set of videos at the NIH, they’re really clear and I like the lady announcer.
The current method of treating cancer is chemotherapy. Chemotherapy is a bunch of drugs that target and kill fast-dividing cells, which unfortunately include hair, sperm, and keep-you-from-barfing cells. Chemo sucks because it’s general – it goes everywhere in your body – and there’s a lot of collateral damage.
Now, the promise of Nanotech is that we could mount a targeted response to cancer – pinpointing and destroying only cancer cells. This guy Ehud Shapiro from the Weizmann Institute of Science, Israel has been working on DNA computers for a while. I linked to an article about the Institute almost a year ago (New DNA Computer Functions Sans Fuel). For a quick overview of how DNA Computers work I recommend reading this Comic Book.
As a summary I will use the analogy that DNA is code that produces proteins. Proteins build everything in your body, from neurotransmitters to snot. The promise of DNA computers is that we can write code that will build proteins that do stuff – like kill cancer cells. What this computer does is produce antisense DNA, which basically muffle a certain part of DNA and prevent it from being read. It actually muffles mRNA, but that’s besides the point.
Instead of silicon chips and electrical circuits, the miniscule machine is made of DNA. And rather than being controlled by electrical signals, it senses changes in its environment and responds by releasing biological molecules.
The biocomputer senses messenger RNA, the DNA-like molecule that helps create proteins from the information in genes. In particular, it can detect the abnormal messenger RNAs produced by genes involved in certain types of lung and prostate cancer.
When the computer senses one of these RNAs it releases an anticancer drug, also made of DNA, which damps expression of the tumour-related gene, researchers report in Nature.
So basically, you could inject DNA computers in your body that monitor DNA transcription and serve to kill off cancer cells when they start dividing out of control. Right now the stuff only works in a highly controlled test tube, but it has a lot of promise.
I got a C+ in genetics (sorry Amma) so you should probably look this stuff up yourself.