LEWISTON, Maine — Oscar-winning actor Robert De Niro received a doctorate of fine arts during the 146th commencement of Bates College.

During a 15-minute address Sunday that was by turns sincere and irreverent, De Niro drew a steady stream of laughter from the 463 graduating seniors and more than 2,000 guests who gathered at the Lewiston campus.

De Niro, who left high school when he was a teenager to pursue an acting career, was one of three high-profile guests who received honorary degrees at the Bates College commencement. PBS “Newshour” senior correspondent Gwen Ifill and Princeton University molecular biologist Bonnie Bassler also were honored.

De Niro won a best actor Academy Award for “Raging Bull” and best supporting actor Oscar for “The Godfather, Part II.” He earned four more Oscar nominations.