The association, which publishes the prestigious journal Science, is among the largest scientific organizations in the world, with more than 10 million members.

John Rossi (Photo by Walter Urie)

AAAS Fellows are elected by their peers following nomination and extensive review by AAAS leadership. The AAAS will recognize Rossi and 538 other newly elected fellows for their contributions to science and technology during the AAAS Annual Meeting in Vancouver, Canada, on Feb. 18.

Rossi was elected for his scientific efforts in developing specialized molecules known as ribozymes, small interfering RNAs (siRNAs) and other small RNAs as therapeutic agents for the treatment of human immunodeficiency virus-1, or HIV-1, infection.

“Dr. Rossi is one of the most accomplished scientists in the field of small interfering RNA research,” said Michael A. Friedman, M.D., president, chief executive officer and Irell & Manella Cancer Center Director’s Distinguished Chair of City of Hope. “His insights and advances in RNA-based therapies for HIV/AIDS have opened important new avenues of research and brought new hope to patients living with the virus.”

RNA, short for ribonucleic acid, is closely related to DNA and can act as a messenger to help translate the genetic code into proteins. Ribozymes also are made of RNA but act as a sort of molecular scissors that cut messenger RNA, preventing the successful translation of the genetic code.

In 1990, Rossi and his City of Hope colleagues were the first to propose using ribozymes to arm human blood stem cells with the ability cut HIV RNA in the body, effectively blocking the virus from reproducing and spreading. Seven years later, the team launched the first clinical trial in the world studying this approach to overcoming HIV infection in patients with AIDS-related lymphoma.

Finding limited success with the early technology of the time, Rossi and his colleagues made a couple of key adjustments: They used a better method of delivering the therapy to human blood stem cells, and they added a new approach to the mix called RNA interference. The technique uses small interfering RNAs, or siRNAs, that guide a complex of enzymes within cells to chop up messenger RNA. Rossi and his team designed siRNAs that target key HIV genes, blocking the virus’ ability to replicate.

In 2008, the team opened the first-ever clinical trial combining siRNA, a ribozyme and third form of RNA, called a decoy, in an HIV-based viral vector to create a three-pronged approach to stopping HIV. The method arms blood stem cells with the ability to produce the three anti-HIV RNA molecules and aims to give HIV/AIDS patients lasting resistance to the virus. This trial is ongoing.

Rossi is the first holder of the Morgan and Helen Chu Dean’s Chair for the Irell & Manella Graduate School of Biological Sciences at City of Hope.