US duo win Nobel for gene regulation breakthrough

US scientists Victor Ambros and Gary Ruvkun won the Nobel Prize in Medicine on Monday for their discovery of microRNA and its role in how genes are regulated, solving a decades-old mystery, the Nobel Assembly at Sweden's Karolinska Institute said.

If gene regulation goes awry, it can lead to serious diseases such as cancer, diabetes, or autoimmune illnesses.

"Their groundbreaking discovery revealed a completely new principle of gene regulation that turned out to be essential for multicellular organisms, including humans," the jury said.

Ruvkun said he was shocked to win the prestigious prize.

"It's quite a sea change," the 72-year-old professor at Harvard Medical School told AFP after receiving the news in a call from the prize committee in the early hours of Monday.

"I've won other awards in the past, but those were very quiet in comparison."

"There's already been TV crews and photographers, and 300 email messages from friends!" he said, as his dog barked at the front door with more reporters arriving.

Ruvkun shared that he and Ambros are "buddies" and had a congratulatory video call that morning.

"We just FaceTimed to high-five. We've been friends for years."

Ruvkun told AFP the pair would be "celebrating like crazy," praising Ambros as "always positive and wonderful." The Nobel committee failed to reach Ambros by telephone to give him the news. He heard it instead from an SR reporter who called.

"Wow, that's incredible! I didn't know that," the 70-year-old professor at the University of Massachusetts medical school said, adding: "Good. Wonderful."