The hype's losing steam: Gene research will not necessarily produce quick-fix cures for cancer and heart disease; biology is more complicated than that

Publisher: The Ottawa Citizen

Page: A17 Section: News Page Name: Arguments

Byline: Jacob Berkowitz

Source: Citizen Special

It's too soon to ring the death knell for the hype surrounding gene therapy and personalized genomic medicine, but for those watching closely, the inflated promises are beginning to develop a slow leak.

What that means for most of us is this: If you're waiting for a quick genetic fix for what ails you, forget it. Unless you have a single-gene disorder -- such as Huntington's disease or cystic fibrosis -- you've got a much better chance of enjoying retirement by hitting the treadmill or putting down that doughnut.

This notwithstanding recent front-page headlines announcing that an international team of molecular biologists has completed the next major step in organizing the data produced by the Human Genome Project.

The Haplo-type Map is a new reading of our genome that divides the three billion bits of DNA into larger, identifiable regions, making it easier to look for disease-related genes by narrowing the area of search. Breathless news stories on this technical achievement have suggested that this is the key to treating major killers such as heart disease and cancer.

Whoa. "Heart disease" and "cancer" are two broad classes of illness. The promise of genetic cures for them echoes those labels from 19th-century curative potions that claimed to treat conditions from gout to hair loss. In truth, the age of genomics has shown that, as with most else in life, the quick fix is very long in arriving -- if it ever comes at all.

To see why, we need to reach back across the last century. Without a doubt, genes were the 20th century's in-thing. With good reason. The last hundred years witnessed an impressive progression, from the hypothesis of a molecular basis for heredity to the identification of DNA as the blueprint code.

Then the century and millennium went out with a terrific genomic bang: The completion of the Human Genome Project (not to mention several other less-highly touted, and arguably more scientifically important genome sequences, including that of a lowly worm and the all-important lab mouse).

But the more we learn about genes, the more we're interested in other molecules. It turns out that peeling back the layers of the human genome is a little like getting into a major renovation project on a large, old house: Remove the plaster and you reveal a far more complex and time-consuming job than you ever could have imagined.

The Human Genome Project and other genome sequences have laid bare a staggering molecular complexity. Some biologists worried that the HGP would result in an era of biological reductionism, with people suddenly arguing, for example, that criminality is all in the genes.

Instead, just as with the home renovation, what has emerged is a renewed and more profound sense of the complexity of things. As geneticists, behavouralists and neurologists poke at genes in more detail, they arrive not at the answer to their questions but at more questions.

How is it that with identical twin brothers -- two men developed from the same egg and with identical genes -- one develops schizophrenia, but not the other? For those engaged in following the intricately tangled thread of biological complexity the answer to this question goes beyond the well-worn and intellectually befuddled nature-versus-nurture debate.

This genes-versus-environment dichotomy is about as logically salient today as a thoughtful discussion of who's more human, men or women?

What's being challenged today is the notion that genes ought to be the point of departure for molecular studies, that is, the idea of the genome as the immutable "blueprint" or "book of life." Like the Bible and its ecumenical readings there are, it appears, many interpretations of a single genetic book.

This not to say that there aren't many geneticists for whom the trees are the forest. In studying "genohype," Timothy Caulfield, the Canada Research Chair in Health Law and Policy at the University of Alberta, concluded that exaggerated claims are often coming from the scientists themselves, with journalists simply serving as willing public messengers.

But as the U.S. cell biologist turned philosopher of science Lenny Moss notes in his book What Genes Can't Do, "Biological order is distributed over several parallel and mutually dependent systems such that no one system, and certainly no one molecule, could reasonably be accorded the status of being a program, blueprint or set of instructions."

Indeed, researchers are finding that many genes are regulated by proteins. Enzymes and hormones form part of feedback mechanisms, some greatly influenced by environmental factors, that turn genes "on" or "off." And there are the revelatory prions, such as those that cause mad-cow disease, in which all of the life information is encoded in proteins.

So who's driving the car of life? While it's comforting to look for a single genetic switch, biologists are instead finding an ecology of gene-protein-cell-environment interactions that call for an understanding of their relationships in order to determine how best to tweak the system.

As a result, the human HapMap is one more guide on an incredible journey. But if you're waiting for the magic genetic bullet, hedge your bets with a salad and long walk after dinner.