Recent drugs that have been created can help treat some of the toughest diseases out there—from Alzheimer's and Parkinson's to all types of cancers. The only problem: They kill some people. But new breakthroughs in cell engineering might usher in a new era of personalized medicine where drugs can be tested for side effects without having to test the drug in humans.
Scientists at San Francisco's Gladstone Institutes announced Thursday that they've successfully reprogrammed human skin cells into brain cells, and recently, a team turned skin cells into working heart cells.
The idea, according to Yadong Huang, head of the Gladstone study, is to scrape cells from an Alzheimer's patient's skin, turn it into a brain cell, and try out different therapies on the newly-created cells. If there's an adverse reaction, doctors will know not to give that drug to the patient.
"There are some drugs that can't be put on the market because some patients respond badly to a drug. If the drug kills 5 percent of the patients, the FDA won't approve it," Huang says. Instead of risking side effects, which range from pesky to deadly, doctors will know with better certainty if a drug is suited to a patient.
Because Huang's method would use a patient's cells, the newly-programmed cells would have the patient's DNA.
"If we make reprogrammed cells from an individual patient, we can test different types of drugs on those cells. A patient might not respond well to drug A, but will respond to drug B."
Huang's method also lets doctors dream of a day when they could regrow functioning organs—but that's much farther off.
"Hopefully someday, we can transplant those cells back into a patient," Huang says. But he says there are many hurdles to clear, such as figuring out how to functionally integrate new cells into the brain.
"There's a lot of general neuroscience knowledge we just don't have yet," he says.
That's why, for now, doctors are focusing on crafting personalized treatments for people suffering from disease. The process involves turning skin cells into what are known as iPS cells—a type of stem cell that can then be respecialized into other types of cells.
Clay Marsh, executive director for Ohio State University's Center for Personalized Health Care, says the process is getting easier every day and scientists may soon be able to turn skin cells into any type of cell.
But while testing drugs in a test tube seems like a good idea, it also raises problems for diseases that strike multiple body systems, such as cancer.
Testing drugs in a test tube "gives us a piece of the puzzle, but not the whole puzzle," he says.
"Even if a drug, in isolation, affected the derived cells in a positive way, that doesn't mean it'll affect that person in a positive way," he adds. "Issues like diet, exercise, a patient's mental state are all very important."
Still, a world where each treatment is specialized based on a patient's genetic makeup is just a few years away, both doctors say.
"Instead of treating every patient with the same drug and seeing what happens, we can start being much more precise about what we try," Marsh says.
Jason Koebler is a science and technology reporter for U.S. News & World Report. You can follow him on Twitter or reach him at firstname.lastname@example.org