How does a simple petri dish of DNA constitute the identity of a complex human being—from the way she laughs to her love of Cocoa Krispies? It turns out that the question of how biology determines identity interests not only the philosophically-inclined, but those in the drug and healthcare industry as well.
In a recent study published in Molecular Systems Biology, a computational biology team at Columbia explored the very questions that drive the current research on personalized care: How does a cell take a genotype and translate it into a phenotype? More specifically, how do genes determine our responses to medicine?
“The idea behind personalized care is that each of us is very different - we look different, we behave different, we have clearly different disease susceptibilities. All these things are genetically determined. Genetics also determines our responses to drugs,” Dr. Dana Pe’er, head of that computational biology research team, explained. Like many gadget lovers today, patients are clamoring for one-pill-fits-all cures. Tylenol, for instance, claims to relieve four different types of aches, fever, cold, cramps and arthritis. But with standardization comes the possibility of unpleasant side effects, such as, in the case of Tylenol, liver damage.
Medicines tailored to individuals would reduce the possibility of such side effects. But wouldn’t personalized care be much more expensive than the generic options we have now? “It would be cheaper!” Pe’er exclaims. “It would do away with the trial and error. A cancer patient has to pay $100,000 for chemotherapy. Won’t it be nice to tell them, ‘This won’t work for you because of your genes?’ Instead of getting it right on the third try, you can get it right on the first try.
”She also points out that avoiding all the adverse effects saves “tons of money and pain,” and that the “right meds put you back in the workforce in one day instead of three.”
A genotype scan currently costs a hefty $399, but patients only need it once in a lifetime. So what’s stopping personalized care from becoming an everyday reality? Part of the reason is that the science hasn’t yet come that far. According to Pe’er, the technology developed to investigate the connection between genotype and phenotype in terms of drug-responses is only a few years old, and the task it faces is gargantuan.
Pe’er analogizes: “Imagine there’s this huge cave, maze-like, with lots of passageways and everything’s pitch dark. Trying to do research on humans is like searching in this cave without even knowing what you’re looking for.”
To improve the search for the human genes that are related to drug resistance, Pe’er and her team focused on an easier subject: yeast, the common “workhorse” that scientists use to develop technology to apply to humans. By manipulating and testing 104 strains of yeast, they improved old search methods that traditionally relied on genetics by creating a new method that also harnesses gene expression (RNA), which indicates which genes are actively used. Their RNA-utilizing algorithm accurately predicted strain resistance for 87 of the 94 drugs tested, effectively narrowing down the number of genes related to drug resistance.
The main opponents of personalized care are not health insurers. For them, Pe’er believes, profits will rise with the reduction of the trial-and-error process which forces insurers to pay up with every treatment. Instead, pharmaceutical companies are the real antagonists: in order to maximize profit, they want standardized drugs to serve the whole population and not just a section of it. Recent pressure from the FDA—which has threatened to take drugs with adverse side effects off the shelves—has lead to heavy investment in a new field that combines pharmaceutical research and genetics: pharmocogenics. Pharmeceutical companies like Eli Lilly, who’ve been involved in legal disputes for marketing unapproved drugs, are now increasingly involved in studies on patient responses due to genetic variation.
But even if all pharmaceuticals participate to produce personalized medicine on a large scale, the truth is that we are not yet ready for personalized care. Patients and doctors are not adequately trained to interpret genotypes and translate them into appropriate treatments.
Specialized knowledge needs to be transferred from genetic-researchers to everyday medical practitioners. As Joel Burrill points out in an interview with Wired Science, unless medical schools adapt their training programs, there will be a shortage of DNA interpreters. Web sites like 23andme.com do a good job of explaining what the data means, but a large-scale implementation of personalized care would require more than Web sites.
Perhaps just as importantly, the legal infrastructure to protect the privacy of genetic information isn’t sufficiently established. It would be a veritable disaster if health insurers or workplaces got a hold of their clients’ or employees’ genetic predispositions to illnesses.Despite these obstacles, Pe’er believes that personalized care will be a reality within our lifetimes. Things are moving, even if slowly, in the right direction.
By Sarah Ngu
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