Chuck Chan, stem cell researcher who discovered how to regrow cartilage, dies at 48

The Stanford Medicine researcher was known for his groundbreaking work and his generous spirit as a mentor and colleague.

- By Jennifer Welsh

Chuck Chan on a road trip to Yellowstone National Park.
Wan-Jun Lu

Charles “Chuck” Kwok Fai Chan, PhD, an assistant professor of surgery at Stanford Medicine, died March 12 at Stanford Hospital surrounded by his wife, parents, siblings, and some of his dearest friends and colleagues. He was 48. 

“Chuck accomplished a great deal in the short time he had,” said Lloyd Minor, MD, dean of the Stanford School of Medicine and vice president for medical affairs at Stanford University. “He knew he was working against the clock, which drove him to persevere in his research. He leaves behind a wealth of foundational stem cell discoveries that will inform the future of rejuvenative medicine. Stanford Medicine mourns the loss of such a talented researcher at such an early age.”

A member of the Stanford Institute for Stem Cell Biology and Regenerative Medicine, Chan discovered the mouse and human stem cells that give rise to bone, cartilage and some types of cells that nurture blood-forming stem and progenitor cells. These stem cells are integral to developing new healing technologies for joints affected by osteoarthritis or skeletal injuries. 

​“Chan was an outstanding scientist with a prodigious intellect and curiosity. He was a giant in the field who we lost way too early,” said Michael Longaker, MD, a professor of plastic and reconstructive surgery and the Deane P. and Louise Mitchell Professor in the School of Medicine. “His work will have a long-lived impact. Decades from now, millions of people with arthritis may be benefiting from his discoveries, and I will say, ‘This work traces back to the Chan lab.’”

Chan trained many young scientists, including undergraduates, CIRM scholars and international students. His colleagues said he was generous with his time, ideas and the secret recipes used in his experiments. He believed there were always more discoveries to make and more Nature papers to write. 

“He was very confident that there was enough science to go around. He was so willing to share, to talk about science, to collaborate because he was confident that there was so much still to discover,” said his brother Ed Chan, a researcher in the plastic and reconstructive surgery department at Stanford Medicine. “He was very open with his science, pushing his teams to present their research and share what they discovered and the new tools they developed.”

Chan identified and isolated essential components needed to encourage the development of skeletal stem cells, which can make bone, cartilage and helper cells for blood-cell precursors. To bring these findings to the clinic, he dabbled in gene editing and even a project using microneedle-based technologies for repairing cartilage with his brother.

“He was a brilliant young scientist, unafraid to explore new technology,” said Irving Weissman, MD, founding director of the Stanford Institute of Stem Cell Biology and Regenerative Medicine, professor of pathology and developmental biology, and the Virginia and D.K. Ludwig Professor in Clinical Investigation in Cancer Research. “Though he didn’t treat patients, he was always thinking about how they’d benefit from his discoveries. We will miss his drive, his empathy, his deep intelligence. Sadly, generations of patients will miss his potential discoveries.”

Boundless curiosity, unrestrained imagination

When he applied to Stanford Medicine’s graduate program, Chan wrote in his personal statement, “If I cannot be a child, then let me be a scientist…scientists have boundless curiosity and an unrestrained imagination.” It was a definition Chan embodied his entire life, friends and family say. 

Though he didn’t treat patients, he was always thinking about how they’d benefit from his discoveries.

Born May 14, 1975, in Hong Kong, Chan moved to the U.S. in early 1982, landing in Anaheim, California, where he could see Disneyland’s famous fireworks displays from his living room window. He was the eldest of six siblings — he had four brothers and one sister. His mother is a homemaker, and his father was in the photographic equipment business during his youth.

“Chuck was the leader of our gang. He was No. 1,” Ed Chan said. “He was always into science — he had a big rock collection; he was into bugs and how the ecosystem works. As a family, we used to laugh at him a bit for his obsessions.”

He attended Alhambra High School, where he played clarinet in the marching band. He started his research career in high school, interning at university labs over the summer. 

He earned a bachelor’s degree in molecular biology from the University of California, Berkeley, in 1999, staying on for two years to complete a research project and publish his work. In 2002, he enrolled in the development biology program at Stanford Medicine, joining Weissman’s lab, where he focused on finding and defining interactions between stem cells that lead to regenerative growth. He earned his PhD in 2011. 

“He explored many things and proved himself to be absolutely fearless in terms of technologies that might advance the field,” Weissman said. 

As a graduate student, Chan was diagnosed with non-Hodgkin’s lymphoma and underwent extensive treatments. “During that time, he did not stop doing science,” said his wife, Wan-Jin Lu, PhD, a research scientist at the Stanford Institute for Stem Cell Biology and Regenerative Medicine. “He managed to publish a paper, defend his thesis, attend lab meetings and support his lab mates.”

Eventually, a bone marrow transplant from his sister gave him an eight-year remission. He was awarded with an independent Siebel Scholar position and built up his lab immediately after earning his PhD. His work focused on the stem cells that give rise to bones and cartilage. 

“Anyone else might have been demoralized by how hard these experiments were. But Chuck seemed like he couldn’t get enough of it,” Longaker said. “That’s what made him a unique and uber-successful scientist.”

Chan worked doggedly to identify the mouse skeletal stem cell, which gives rise to the spongy bone that supports blood, hard bone and cartilage.

“Irv said these experiments would not work, but Chuck did not listen. He went ahead and tried it anyway,” Lu said. Eventually, he grew a piece of bone with a spongey inside and cartilage at the ends. “He was so proud of himself that he brought the bone straight into Irv’s office — it was his once-in-a-lifetime ‘Eureka’ moment that every scientist dreams about.”

Weissman added, “One of the unique aspects of helping great graduate students is that they discover what you doubted.”

That work was published in the top journal Cell and immediately put him on the map as a “researcher to follow,” Longaker said. Very quickly after that, he identified the human skeletal stem cell, again publishing the finding in Cell.

“He became this iconic bone biology person early in his career — it was a testament to his vision for what’s possible,” Longaker said. “He went on to regenerate cartilage and reverse the slow healing of aging.”

When joint cartilage has worn away, bone painfully rubs against bone. Often, a patient’s only solution is pain medication or joint replacement surgery. Chan’s research may lead to ways to regrow cartilage.

“Because he had overcome so much with his health as a grad student, I think it gave him a sense of urgency in his work,” Longaker said. “He wasn’t on faculty long. But wow, his contributions will live forever.”

A lasting impression

Not only was Chan a dedicated scientist; he was an optimist inside and outside the lab — an upbeat person always happy to collaborate, colleagues said. He was also a well-known night owl, sending texts from the lab at all hours.

In the lab, Chuck was in his element. That was what he wanted to do with the people he wanted to do it with.

He took an unusual approach to picking his projects. He pursued the fundamental questions, pushing through ideas at an unusually fast rate. He conducted one experiment, focusing on one question, to decide if that project would work. If not, the next week, he would start a new project.

“He didn’t work on small projects. He wanted to make a difference,” Longaker said. “He was undaunted; no matter how complicated the experiment, he did whatever it took — that’s what made him unique.”

Chan was also a good mentor and group leader. “If someone was having a bad day, they would come to Chuck’s lab. They’d have a few beers, and he would help them through it. He would sit with you and inspire you,” Lu said.

Chan spent about 90% of his time talking about, thinking about or conducting lab work, Lu said.

“The idea of work-life balance wasn’t his focus. It’s work and life, they’re just together,” Ed Chan said. “In the lab, Chuck was in his element. That was what he wanted to do with the people he wanted to do it with.”

Outside the lab, Chuck found a profound connection with Hawaiian culture during a weeklong camping trip along the Maui coastline. This experience ignited a love for the Aloha spirit and the Hawaiian way of life. He was often seen in Hawaiian shirts, spending time at the beach and hiking the island trails. Chuck had a particular fondness for sea turtles, always seizing the chance to seek them out along the sandy shores.

When it came to his family, Chuck was the sterner older brother, Ed said. He pushed his younger siblings hard when they were younger, prepping them to take the SATs by having his siblings live with him for the summer and drilling them every day. “They hated it. But to this day, they all admit that they got into decent schools because Chuck was riding them so hard,”Ed Chan said.

Chan received a Siebel Scholarship Award from 2011 to 2013, a Prostate Cancer Foundation Young Investigator Award from 2013 to 2016, a National Institutes of Health Pathway to Independence Award from 2015 to 2020, and an American Federation for Aging Research and Arthritis National Foundation grant in 2018 and 2020. 

Chan is survived by his wife, Wan-Jin Lu, of Redwood City, California; parents Albert and Anna Chan; and his five siblings: Edward Chan, Andrew Chan, Marvin Chan, Brian Chan and Karen Haas. He has nine nephews and nieces.

About Stanford Medicine

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