Kathleen Quinlan, currently starring opposite Kurt Russell in the hit “Breakdown,” has been cast to star opposite Billy Crystal in the Michael Lehmann-helmed comedy “My Giant” for Castle Rock Entertainment.Washington Bullets center Gheorghe Muresan plays the title character in the comedy about a sleazy agent (Crystal) who attempts to exploit a kind-hearted, big-boned man as his meal ticket. Quinlan will portray the agent’s estranged wife, who has moved to Chicago, where she works as a drama teacher. On the way to Vegas, Crystal’s character, with the “giant” in tow, stops to hit her up for money. She grows fond of the Muresan character and together they help the agent learn the importance of family. Crystal will also produce the pic, based on a screenplay by Crystal and David Seltzer. In addition to Paramount’s “Breakdown,” Quinlan appears in two other upcoming pics, Par’s sci-fi thriller “Event Horizon” and the indie “Lawn Dogs,” a family fantasy drama from Rank. Quinlan, whose acting debut came in “American Graffiti,” has also appeared in such films as “Apollo 13,” “The Doors” and “I Never Promised You a Rose Garden.” Quinlan is repped by manager Chuck Binder and her attorney, Nanette Klein, of Kleinberg, Lopez, Lange, Brisin & Cuddy.