Turning Genes On and Off

The simplest way to control something is to turn it on or off. (Wish I could do that with my toddler.) A breakthrough in turning genes on or off at the chromosomal level has been made using synthetic peptide nucleic acid (PNA) and specifically designed RNA. (Medical News Today, August 1, 2005)

The central dogma of molecular biology, of which there are some exceptions, states that cellular machinery uses the information contained in DNA to make RNA; RNA is then used to make proteins. Currently, most techniques focus on blocking RNA before they can participate in making a protein, but this approach is far from perfect.

Researchers designed PNA and RNA to target specific DNA sequences before any RNA is made. They’ve been able to inhibit the expression of nine different genes in cancer cell cultures using these nucleic acids. Finding that genetically engineered RNA can turn off genes could mean that our own body is already using this particular method of controlling gene function. If so, it would be another point of attack for drug therapy.

“Virtually every disease starts at the level of malfunctioning gene expression, or viral or bacterial gene expression,” said Dr. David Corey, professor of pharmacology and biochemistry. “This is an approach that could theoretically produce a drug for the treatment or cure of almost any disease.”

As I’ve learned both in the lab and at home, being able to turn something on or off is just the beginning. More sophisticated ways of controlling genes would be to regulate when, where, and how much they are expressed. Now if only I could find the on-off switch. It must be around here somewhere.