Roger Tsien, a UC San Diego scientist who shared the 2008 Nobel Prize in chemistry for research that led to the development of fluorescent proteins used to illuminate tissue and track biological processes, has died, according to a statement from the university.
Tsien died on August 24 while bike-riding in Eugene, Oregon, a UCSD Health spokesman confirmed late Wednesday. Additional details about his death have not been revealed, however, and the circumstances remain unclear. He was 64, and had been a professor at the UC San Diego School of Medicine for 27 years.
The 2008 Nobel Prize in Chemistry was awarded to Tsien, Osamu Shimomura of the Marine Biological Laboratory in Woods Hole, MA, and Martin Chalfie, a biologist at Columbia University, “for the discovery and development of the green fluorescent protein, GFP.”
Shimomura showed how the jellyfish Aequorea victoria glowed bright green under ultraviolet light, and identified how a green fluorescent protein (GFP) made it possible. Chalfie showed how GFP could be used as a biological marker. Tsien found ways to make GFP glow more brightly and consistently, and went on to create fluorescent peptides in other colors, enabling scientists to track different cellular processes at the same time.
The fluorescing proteins they created made it possible for scientists to study changes in living cells and other organisms, illuminating cellular acidity and gene expression, among other things.
Tsien told Xconomy in a 2008 interview that he moved on to other areas of interest after developing some new applications for GFP in molecular biology. He compared himself to John C. Fremont, the 19th century explorer and mapmaker “who finds the pass but who is not the homesteading type.”
In the statement released by UC San Diego, chancellor Pradeep Khosla said, every honor Tsien received was “justly deserved, and always received with humility.”
In 2009, Tsien and Kevin Kinsella of Avalon Ventures founded San Diego’s Avelas Biosciences to develop fluorescent proteins that change color in the presence of cancer cells. The technology, which has advanced into early clinical trials for breast cancer, is meant to make it easier for surgeons to identify and remove tumors and metastatic tissue.
Avelas also has been developing a method to potentially deliver toxic chemotherapy drugs inside cancer cells.
After forming Avelas, Tsien went on at UC San Diego to develop an injectable fluorescent protein that illuminates hard-to-identify peripheral nerves in mice. The technique, if successful, could enable surgeons to avoid nerves when removing damaged or cancerous tissues.