Why Gene Sequences Don't Equal Cures

One of the major disappointments of the new millennium so far has been the failure of genomics to yield promising new medical treatments. This was supposed to save pharma, and, not incidentally, us, by letting us read the very molecules where things first went wrong.  Cures for cancer!  No more diabetes!  Take that, Cystic Fibrosis!

But cures have not really been forthcoming, and a post by Derek Lowe suggests some of the reasons why:

A new study, one of those things that could only be done with modern sequencing techniques, has given us the hardest data yet on the genomic basis of cancerous cells. This massive effort completely sequenced the tumors from 50 different breast cancer patients, along with nearby healthy cells as controls for each case. 

Over 1700 mutations were found - but only three of them showed up in as many as 10% of the patients. The great majority were unique to each patient, and they were all over the place: deletions, frame shifts, translocations, what have you. The lead author of the study told Nature News that the results were "complex and somewhat alarming", and I second that, only pausing to drop the "somewhat". I add that qualification because these patients were already more homogeneous than the normal run of breast cancer cases - they were all estrogen-receptor positive, picked for trials of an aromatase inhibitor.

In retrospect, it's easy to develop a healthy skepticism about the possibilities of genomics--at least, the early stages that we're now in.  Sequencing the human genome isn't really like being able to read the assembly instructions for the human body.  The instructions are in a nucleic acid code that gets acted on by lots of different agents to turn them into a final product like a protein, and we don't really know the code yet.  Sequencing the human genome was more like getting an instruction manual for something important--in a dead language for which we have no Rosetta Stone.

But I didn't have that skepticism at the time, and neither did a lot of people in the biosciences.  The human body keeps turning out to be way more complicated than we hope or expect.