Medicine has seen its equivalent of the splitting of the atom: the ability to take apart, reassemble, and release the incredible power locked in genes and cells. The breakthrough has resulted from the merger of interlocking fields—gene therapy and cell therapy—which are now spawning near-miraculous treatments and cures. But where atomic research had a single, explosive debut, gene- and cell-based treatments have emerged in fits, after many false starts.
One huge step forward came in 1985, when researchers began shuttling genes into mammalian cells by first transferring them to a virus. The genes hitched a ride inside the virus, ultimately entering the cell nucleus and working alongside native genes already in place. Then things went wrong. Not only did gene therapy fail to cure disease, but Jesse Gelsinger, a boy with a rare metabolic disorder, died in a clinical trial in 1999.
Only recently have cell and gene therapy begun to triumph, by borrowing from and blending into each other’s approaches. One stunning proof of principle occurred in 2007, when German researchers treated a 40-year-old patient for HIV and leukemia with stem cells lacking an HIV receptor, making them resistant to the virus. The patient was cured and, three years later, remains well. In another landmark success, scientists in Italy and the United States cured “bubble” babies who have a malfunctioning gene for the enzyme adenosine deaminase, which causes a buildup of toxic products that destroy immune cells. Doctors gave the patients stem cells containing copies of a properly functioning gene for the enzyme; the babies’ immune systems were then able to reconstitute themselves.
The combined therapy is assuming even greater power as scientists manipulate genes to wind ordinary cells back to an embryonic state. Embryonic cells could restore brain and immune function and regenerate organs. “The time is coming when we’ll repair heart tissue after a heart attack and restore blood flow to limbs that would otherwise be amputated,” says stem cell researcher Robert Lanza of Advanced Cell Technology in Massachusetts. “We’ll look back and say, ‘Can you believe how people used to suffer?’”
Jill Neimark also contributes to Psychology Today and Spirituality and Health. Her children's novel, The Secret Spiral is due out in June.
