TENS of thousands of pop culture fans descended on the Comic-Con International event this week in San Diego that in recent years has changed from a convention of comic book lovers to a Hollywood movie bazaar. Comic-Con began its 40th year on Wednesday night with a preview of new comic books, graphic novels, science-fiction and action movies, television shows and videogames. More than 125,000 people – many dressed as their favorite comic superheroes, “Star Wars” or “Star Trek” characters and even “Ghostbusters” - swarmed the convention that runs through July 26. “Years ago, when Comic-Con was in its infancy, the attendees were 99 percent teenage fans,” said comic book great Stan Lee, who will be showcasing a new Activision videogame “Marvel Ultimate Alliance 2” game at this year's convention. “The Con was all about comic books, their artists, writers and editors. Today, it's still about comic books, but the major emphasis is on movies, TV shows and videogames ... It has become a huge ‘entertainment' Con rather than just a comic book Con.” Several Hollywood movie studios will screen new films and host elaborate question-and-answer panels with actors and directors of major upcoming releases including Paramount Pictures' “Iron Man 2,” Walt Disney Pictures' “Alice in Wonderland” and 20th Century Fox's “Avatar.” “I make movies for the 14 year-old in me, and I know they're going to dig this stuff,” said “Titanic” director James Cameron, who unveils his highly anticipated new 3D sci-fi film, “Avatar” and Ubisoft's “James Cameron's Avatar” 3D videogame. Holly-Con? Starting in the 1990s, Hollywood began to see that their core, target audience - mostly teenagers and young adults - either turned out for “The Con” or followed it closely on the Internet. The studios learned they could utilize the event to promote films and generate ticket sales at box offices. Summit Entertainment, which will debut footage for “The Twilight Saga: New Moon” on Thursday, saw excitement from last year's “Twilight” panel generate early buzz that helped propel that movie to a $382 million global box office haul. Now, television networks are invading Comic-Con to find fans for shows like ABC's “FlashForward” and “The Middle,” starring Patricia Heaton, as well as Fox's comic book-based “Human Target” and its high school singing drama “Glee.”