In the Marvel comic, Uncle Ben and his wife Aunt May raise Peter Parker (The Social Network's Andrew Garfield). After Ben is killed by a burglar, Peter is inspired to become a hero with his new-found superpowers. Cliff Robertson played Uncle Ben in the 2002 film starring Tobey Maguire.
Sheen's casting follows that of Emma Stone (Superbad) as Peter's love interest, Gwen Stacy and Rhys Ifans as the film's unnamed villain. Sally Field is in early talks to play Aunt May, according to Reporter.
Sheen, perhaps best known for his work as President Josiah "Jed" Bartlet on The West Wing, most recently appeared in the films Imagine That and Love Happens.