Let me plug it again: the Scientific American July issue article, “Untangling the Roots of Cancer,” a must-read for anyone interested in the biological processes of cancer. The article describes three new hypotheses about processes that go on in the nuclei of cells that may be part of the genomic and chromosomal changes that lead to cancer and drug resistance.
And in the November issue…
It seems that, since the decoding of the human genome, some simple ideas about how genes are transformed into proteins and thence into our flesh and blood have come up short. First, the standard thinking was that one gene was transcribed into one protein and the protein did the work of constituting the organism. The problem was: there were ~30,000 genes identified and 100,000 proteins. Didn’t add up. It suggested that other processes must be going on that affect how genes contribute to proteins. This was a big disappointment to pharmaceutical companies who yearned for a similar formula: one gene = one protein = one drug = $1 billion.
Now part of the problem of adjusting the math between genes and proteins may be coming to light by knocking off another standard biological assumption: that ~98% of the DNA in the chromosomes is “junk” and plays no role in constituting the final form of the organism. Now it appears that isn’t so and this DNA “desert” has some role that does indeed affect gene expression as proteins, and the article, “The Unseen Genome: Gems among the Junk,” spells out these recent ideas.
They suggest two things:
- There are sections of DNA that are transcribed into RNAs that play a role in the regulation and interaction of the protein-coding genes. These “genes” don’t do proteins, but they do do RNAs that may affect the outcome of standard protein-coding processes.
- >There is essentially another layer of information swirling around chromosomes called the “epigenetic layer” (epi = besides, upon) comprised of proteins and chemicals that have sometimes transient affects on genetic machinery that may account for the great variety seen in genetic outcomes or phenotypes.
All this is pretty new and speculative, but it seems part of a trend: the complexity and nuance of genetic processes is more variable and intricate than imagined. The complexity of life processes gets deeper and subtler as we go. The animations we’ve all seen of the elegant, twisted DNA ladder untwisting, unzipping, and molecules fitting into DNA templates to be further translated into proteins is highly simplistic. The problem is that the mastery of cancer is going to require understanding this complexity and developing ways to treat the disease in the face of it.
If you’re a mystery buff, the article is even a two-parter. The second half will be in the December issue.