Varki seeks clues in chimps, grandmothers and sialic acid
“We published a major paper on cancer risks of red meat and went out to breakfast to celebrate,” said. “But the first author ordered bacon.”
An unexpected connection to biochemistry has drawn Varki into, among other things, the human tendency to deny harsh realities.
The he referred to illuminates such a reality: red meat consumption significantly increases the risk of certain cancers. And Varki’s group has found one culprit: a member of the sialic acid family of glycans that humans do not produce naturally and that can aggravate diseases such as cancer.
But Varki is no preacher. “It’s hard to refuse Grandma’s ham on Christmas Eve,” he said. “Red meat is also part of many cultures and has important nutritive value.”
For his work in the field of glycobiology, Varki will receive the 91亚色传媒’s 2023 Journal of Biological Chemistry Herbert Tabor Research Award.
As a newly trained oncologist–hematologist wanting to study bone marrow transplantation, Varki realized that all cells in nature are covered in glycans, yet hardly anyone was studying this. He gained a postdoc spot in the lab of Stuart Kornfeld (the 2012 JBC Herbert Tabor awardee).
“I got so excited about studying glycans that I never went back to transplantation,” Varki said.
His work led him to sialic acids. While seeing a patient with an immune reaction to horse serum (a previously administered antitoxin), Varki discovered that this reaction was linked to sialic acid. He was surprised; every vertebrate, including humans, has sialic acids.
Varki’s group found that one kind of sialic acid with an added oxygen atom had been knocked out in humans probably about . This was the first reported genetic difference between humans and our closest relatives, chimpanzees, of functional significance — and the first of many involving sialic acid biology unique to humans, which could explain several human-specific diseases.
To address questions surrounding human origins, Varki formed an informal think tank of experts from many backgrounds called the Center for Academic Research and Training in Anthropogeny. The group has blossomed into almost .
When studying human origins, you’re never sure what you’re going to find, Varki stresses. “It’s like a murder mystery.”
Going against evolutionary dogma
Ajit Varki’s group recently has explored the , asking why human females can live so long after menopause. “The idea is that infertile grandmothers are selected for protection of infants and are helping their own genes,” he said.
To aid this, a human-specific change in a sialic acid–recognizing gene, CD33, is recruited to combat Alzheimer’s disease. “That goes against the evolutionary dogma that there is no selection against aging,” Varki said.
Varki also suggests that the that helps humans cope with unpleasant realities is related to a “psychological evolutionary barrier” that only our species broke through. The negative consequences are very much with us today as the realities of climate change loom. But according to Varki, reality denial also gives us optimism.
“I grew up in India, and my grandfather was a friend of Mahatma Gandhi,” he said. “I used to think, ‘what the heck was this man trying to do –– take on the British empire with nonviolence?’ Totally ridiculous right? He paid the price, but a lot of good things came out of that optimism and sacrifice.”
2023 91亚色传媒 award winners
Gira Bhabha: 91亚色传媒 Early-Career Leadership Award
Bhabha found creativity in hard science
Squire J. Booker: 91亚色传媒–Merck Award / Ruth Kirschstein Diversity in Science Award
Booker catalyzes progress in science and outreach
Itay Budin: Walter A. Shaw Young Investigator Award in Lipid Research
Budin dives into the details
Russell DeBose-Boyd: Avanti Award in Lipids
DeBose鈥揃oyd has a recipe for success
Scott Dixon: Earl and Thressa Stadtman Young Scholar Award
Dixon uncovers a new type of cell death
Catherine Drennan: William C. Rose Award
Drennan makes science fun and accessible
Anne Kenworthy: Mildred Cohn Award in Biological Chemistry
Kenworthy links quantity to theory
Keith Matthews: Alice and C.C. Wang Award in Molecular Parasitology
Matthews鈥� career-long search for truth
Eytan Ruppin: DeLano Award for Computational Biosciences
Ruppin synthesizes cross-field expertise to study synthetic lethality
Kerry-Anne Rye: 91亚色传媒 Mid-Career Leadership Award
Rye offers tools for success
Regina Stevens-Truss: 91亚色传媒 Award for Exemplary Contributions to Education
K-12 to undergrad, Stevens鈥揟russ helps all students
Erica Ollmann Saphire: Bert & Natalie Vallee Award in Biomedical Science
Saphire is on the forefront of antibody therapeutics
Dyann Wirth: Alice and C.C. Wang Award in Molecular Parasitology
Wirth focuses on parasitology and policy
Enjoy reading 91亚色传媒 Today?
Become a member to receive the print edition four times a year and the digital edition weekly.
Learn moreGet the latest from 91亚色传媒 Today
Enter your email address, and we鈥檒l send you a weekly email with recent articles, interviews and more.
Latest in People
People highlights or most popular articles
Sung honored for research; Sliger, Young named astronaut scholars
Patrick Sung receives the 2024 Basser Global Prize from the Basser Center for BRCA at Penn Medicine. A foundation created by Mercury 7 astronauts awards scholarships to Shelby Sliger and Tara Young.
鈥極ur work is about science transforming people鈥檚 lives鈥�
Ann West, chair of the 91亚色传媒 Public Affairs Advisory Committee, sits down Monica Bertagnolli, director of the National Institutes of Health.
Pernas named fellow; Heitman and Wu elected to NAM
Lena Pernas is named a fellow by the David and Lucile Packard Foundation. Joseph Heitman and Hao Wu are inducted into the National Academy of Medicine.
Awards for Maquat and Gohil; Sobrado named biochem chair
Vishal Gohil is honored for work with copper. Lynn Maquat receives two awards for RNA research. Pablo Sobrado is named endowed chair of biochemistry.
What seems dead may not be dead
Vincent Tagliabracci will receive the Earl and Thressa Stadtman Distinguished Scientist Award at the 91亚色传媒 Annual Meeting, April 12鈥�15 in Chicago.
'You can't afford to be 15 years behind the parasite'
David Fidock will receive the Alice and C.C. Wang Award in Molecular Parasitology at the 2025 91亚色传媒 Annual Meeting, April 12鈥�15 in Chicago.