On the run ... Roxanne Pallett is taking part in Race For Life - The Sun

Her treasured gran died from a brain tumour when the Waterloo Road star was just 16.

Now Roxanne is putting on her trainers to raise cash for Cancer Research UK — along with Sugababe singer Heidi Range and telly host Christine Bleakley.

Brunette beauty Roxy told TV Biz: "I will be thinking of my grandmother every step of the way. She was the most beautiful woman I have ever met."

Roxy recalled how her mum worked three jobs to make ends meet so her gran, Monica, brought her up.

But her childhood was shattered when Monica's tumour was diagnosed in 1999 at the age of 62. She died just months later.

Roxanne said: "My grandmother was like my second mum. When she was diagnosed, I had to become an adult overnight.

"This was the lady who taught me how to read and write, how to cut up my food. But by the end of it, it was a complete role reversal. I was cutting her food up and reading to her.

"It is beautiful in an ironic way as we changed places but I was devastated and if it hadn't been for my acting and aspirations, I definitely don't know what would have happened to me."It could have been a different story for me if I hadn't had acting as an outlet. I could have easily fallen by the wayside."

She added: "One minute we were a family around the dinner table, going to the cinema, having barbecues and then something like this completely turned the entire family's lives upside down. But I know she would be so proud of everything I have achieved in my career and how much I have tried to help charities."

Now the stunning actress — voted 40th sexiest woman in the world by Sun readers last month — is limbering up for Race For Live in BOLTON on July 1, with her mum and aunt.

Roxanne admitted: "I'm not really your typically sporting person. I spent my entire childhood trying to forge my mum's signature to get out of PE.

"But we have been training on the Wii and even doing zumba in the kitchen, to the shock of the window cleaners!

"I end up with the hiccups and my mum gets a stitch, so we make each other laugh.

"My grandma would love the fact we are doing this. We are dressing up in lots of pink and will probably look like Lady Gaga. But it's really fun and unites families — cancer can affect everyone."

Sugababe Heidi will be doing the Race For Life at AINTREE, Liverpool, with her mum on Sunday in memory of her grandfather Pop, who died of stomach cancer aged 61. The Dancing On Ice star — who is set to dress up for the occasion — said: "I lost Grandad Pop when I was 14.

"He was really young and unfortunately loads of people taking part in the race have been affected by cancer. I will be thinking of him on Sunday."

TV host Christine — engaged to Chelsea star Frank Lampard — will be running in BLACKHEATH, south-east London, on July 1. She said: "My good friend and one of the best producers I've worked with, Una O'Hanlon, passed away from breast cancer 12 years ago. She had two young boys.

"And just this week Frank lost a friend called Danny Fullbrook, who was only 40 years old."

Roxanne, Heidi and Christine have come together to encourage women to sign up to Vodafone's JustTextGiving service to boost their fundraising potential for UK's Race For Life.

Anyone who wants to sponsor the celebrity runners can text 70070, the name such as ROXY82, HEID83 or CHRS81 and the amount you would like to donate

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