08/05/2008 at 02:00 PM EDT
Christina Applegate, who announced on Aug. 2 that she has been diagnosed with breast cancer
, will find participating in Sept. 5's Stand Up To Cancer
telethon "comforting," the producer of the one-hour, televised fundraising event tells PEOPLE.
"We love her, and that's why we reached out to her, and she happily agreed to participate," the telethon's producer Laura Ziskin, herself a breast-cancer
survivor, tells PEOPLE, adding she reached out to the Samantha Who?
star before she announced her diagnosis.
"To be on the show and to hear other people, it's comforting to be around other people who've been through it," says Ziskin – adding that a sense of community among those whose lives are affected by cancer is key to the special event, which will air simultaneously on ABC, NBC and CBS.
"This is really the vibe of the show," says Ziskin, whose other producer credits include the Spider-Man
franchise, as well as the Oscars. “I hope [Applegate] feels it. We are all there for her now, and know what she's going through. We're all thinking of her and praying for her."
Regarding Applegate's role on the telethon, which will also feature
the likes of Jennifer Aniston
and Meryl Streep, Ziskin tells PEOPLE, "I'm in the midst of doing the script now, and obviously because of her diagnosis that may change, but I'm looking forward to talking to her about what she can do on the show."
Ziskin also says that all the guest stars, including Applegate, will also answer telephones from viewers calling in pledges.
As for words of encouragement to Applegate, 36, Ziskin, whose breast-cancer diagnosis was made four years ago, said, "She found it early. She's going to get through the treatment, and she'll be okay. She needs to say, 'I have an illness, I have to treat it, and be good to my body and not over-stress myself,' and then she'll get well."