COMPLICATIONS MULTIPLY, THE NOBEL RECEDES. But, maybe good news.

Linda went to the Borrego hairdresser.  Once.

 

I thought I had securely wrapped my noticeably aging brain around the concept of nucleic acid.  There were, I rather smugly thought, two kinds – DNA and RNA*.  DNA carries the molecular code, thus assuring that when we humans reproduce our offspring are also human, and moreover somewhat resemble us.  We do not give birth to toads or lungfish, for instance.  RNA also has important functions, chief among which is to act as a “messenger”, relaying  the information stored on  DNA to the machinery for manufacturing proteins.    DNA was double-stranded (usually), RNA mostly single-stranded. Double-stranded  DNA was shaped  in the famous “double helix”, and consisted of a sugar-phosphate backbone to which were attached nucleic acids.  There were four nucleic acids: adenine (A), cytosine (C), guanine (G), and tyrosine (T).  These “nucleotides” occur in pairs – A always pairs with T, and G pairs with C.  Hydrogen bonds between these pairs hold the two strands of the double helix together.  RNA is nearly the same, except that it usually is single-stranded, and in the place of the base tyrosine (T) was the very similar base uracil (U).

And that was that.  End of story.

Imagine my consternation then when, during a really rotten breakfast (cheese melted over last night’s spinach, on toast) I read a 25-line article in the latest The Week news magazine, the title of which was “Shape-shifting DNA”.  It appears in the Feb 8 edition, page 21.  The gist of the article is that there is some hope of using the existence of something called “G-quadruplexs” to combat cancer!  What in hell is a G-quadruplex, you might ask. I certainly did.   It turns out to be  four-stranded DNA, held together by some sort of screwy chemical bond – between guanines.  Four of these Gs form a square with another kind of an atom – a “cation”, frequently potassium – in the middle. Furthermore, there are several  varieties of these G-complex things, each with different properties and structures.  They seem  to form in stretches of DNA where there are a plentitude of guanine – our famous telomeres, for instance.  They also are abnormally plentiful in cancer cells.  Which is why this is interesting.

G-quadruplexes have been know from the laboratory for some time, but the recent work of the rather unfortunately named Dr. Shankar Balasubramanian at the Cavendish Lab, Cambridge – yes, the  same place where Watson and Crick worked – has shown that they are fairly common in human cells.  Furthermore, Dr. B has discovered that he can somehow “disable” the things, using something called a “small-molecule ligand”.   Furthermore, when the G-things in telomeres are disabled, the cell dies.  This suggests that if it were possible to target cancer cells with this miraculous ligand, we might cause cancer cells to expire, to no one’s regret.   Dr. B and his lab are working on it**.  But, as someone said about this work, “it’s early days yet.”  So, get cracking.

*Even this turns out to be wrong.  There are four species of nucleic acid.  The two others are LNA and PNA.  Fortunately these other NAs exist only in the lab, so we can forget about them – for now.  No telling what smart people like Dr. B will come up with.

**I actually know quite a bit more about G-quadruplexes, but I have a hunch you've heard quite enough already.  Also - Carolyn and Florence are coming soon and I've got to clean house.