When he was in kindergarten, Jason Pomerantz, MD, drew a self-portrait depicting a surgeon at work in an operating room. He told his mother, “I want to make people not get old.”
Now 38 and a craniofacial plastic surgeon at UCSF, he knows all too well that immortality is the stuff of science fiction. Yet Pomerantz, who splits his time between seeing patients and conducting research in the lab, has not completely given up on the promise science holds for solving seemingly outlandish problems.
“In some ways, regeneration is still science fiction,” Pomerantz says, “although we’re at a point where we have some pretty good leads and some logical approaches to work toward improving the ability to regenerate in people.”In his lab in the Craniofacial and Mesenchymal Biology (CMB) program, a joint venture of UCSF’s schools of dentistry and medicine, Pomerantz is researching questions such as why newts have the ability to regenerate lost limbs and humans don’t – and whether, by switching on or off the right gene combinations, humans could develop that ability as well.
Pomerantz works in UCSF’s sparkling, new CMB lab, which opened in October, one more milestone on the march toward translating scientific discoveries into therapies that can improve patients’ lives – a key goal of UCSF Chancellor Susan Desmond-Hellmann, MD, MPH.
“Our School of Dentistry celebrated a real milestone in October with the opening of the Craniofacial and Mesenchymal Biology Lab [in Health Sciences East 15],” Desmond-Hellmann said in her year-end video address. “This partnership with the School of Medicine enables our scientists to do research and make a big difference for patients with facial anomalies. It’s a great program.”
Pomerantz’s ambitious pursuit of tall orders – and his enthusiasm not only for research, but also for working with patients – inspired UCSF to woo him away from Stanford University in 2009. Nancy Ascher, MD, PhD, chair of the Department of Surgery, and Deborah Greenspan, BDS, DSc, chair of the Department of Orofacial Sciences, jointly recruited Pomerantz as part of the University’s push to build the CMB program into a world-class operation.
“The CMB program was really interested in Jason because he’s a one-of-a-kind clinician-scientist,” says Ophir Klein, MD, PhD, director of the CMB program. “There are very few surgeons in any field who do top-notch research, and in craniofacial plastic surgery, he’s one of the only ones, if not the only one of his caliber, in the world.”
The CMB program started nearly a decade ago, Klein says, but was relatively quiet until recently, when the University built the gleaming, new labs and gave the program some funding.
“The goal in the long run is to be a translational program that takes basic discoveries, thinks about which of those are clinically relevant and translates those that are appropriate into therapies,” Klein says.
A Surgeon-Scientist, New Father
Pomerantz earned his medical degree at the Albert Einstein College of Medicine in New York and completed a residency at UCSF, a postdoctoral research fellowship in regeneration biology at Stanford University and a fellowship in craniofacial surgery at the University of Washington.
He is sturdily built, and the mountain bike in his office – he occasionally rides to Parnassus Heights from his home across the Golden Gate Bridge – attests to his love of the physical fitness opportunities that life in the San Francisco Bay Area affords. He is also the father of a 10-month-old boy, who he says is teaching him biology lessons on a daily basis that he could never learn in a lab.
Pomerantz says he loves his dual role as a surgeon-scientist. Asked if he splits his time between the jobs 50-50, he jokes, “It’s 100-100.”
“Having one foot in both worlds gives you a unique perspective,” he says. “As a clinician, you have a good understanding of the important problems, and as a scientist, I have a way to start answering some of those questions.”
As a surgeon, Pomerantz focuses on reconstructive surgery for patients with physical defects, whether congenital or the result of trauma or disease. He is particularly interested in treating children, such as those with cleft lips or cleft palates. While modern medicine has developed many approaches that help restore normal form and function, nothing to Pomerantz feels like an ideal solution short of helping the body regenerate the malformed or injured part.
Pomerantz looks at the problem from an evolutionary standpoint. He notes that humans already have some regenerative ability. “If we lost a chunk of our liver, we could grow a lot of it back,” he says. “If a baby loses the tip of a finger, it will grow back. We can regrow our stomach lining and replenish our blood supply. But we can’t regrow a finger or a limb as an adult, or our heart after a heart attack.”
For inspiration, Pomerantz turns again to a fascination that developed in his childhood in suburban New City, New York: creepy, crawly things. As a boy, he had several pet reptiles, and when a local high school science teacher went on vacation, young Jason would care for a room full of snakes.
Now, as a surgeon-scientist, Pomerantz is interested in studying zebrafish, newts and salamanders, along with mammals. These are vertebrates, so their regenerative ability inspires more hope for humans than, say, earthworms or sea stars. With newts, he says, “If you chop out a piece of their heart, or a limb, they’ll grow it back.”
A regrown salamander leg will have muscles, nerves, bone, skin, a wrist, digits – “everything we have,” he says. “Why did we lose or never develop the ability that these animals have?”
His work has led him to a single gene that humans have, but newts and others don’t. This gene’s role is tumor suppression, he says; it blocks cell growth. “It’s essentially an emergency brake.”
Newts don’t have that gene, he surmises, because they have more pressing issues than the need to suppress tumors. For them, the ability to regrow a limb is more critical. Now, Pomerantz says, “What if we play with fire and see if what was lost in our system can be regained?”
Of course, perturbing those genes, he says, could interfere with the body’s ability to fight cancer, which is just one of the hurdles he faces. But he is already testing the theories on mice, inducing various forms of injury and seeing whether regeneration is affected if the gene is switched off. The experiments are in the early stages and he can’t report on results yet, but he says that if they prove promising, he’ll move forward with larger mammals.
As for the question of “playing with fire,” Pomerantz says all of medical science is fraught with similar risks. “All drugs are harmful,” he says. “Surgery is causing injury. It all comes down to the benefits. Can you do more good than harm?”