Posts Tagged ‘national-cancer’

Research reveals mechanism behind cell protein remodeling

According to the National Cancer Institute, more than a third of all human cancers are driven by mutations in the Ras family of genes. When Ras is activated, it promotes tumor growth but also activates autophagy which helps to sustain that growth. These cancers remodel proteins using the cellular self-cannibalization process known as autophagy to capture and degrade intracellular proteins and protein-containing organelles. Since Ras-driven cancers often rely on autophagy for growth and survival, this raised the question: Is proteome remodeling by autophagy important, and if so, by what mechanism?

This question was answered in research published in the current online edition of Molecular Cell, by senior author Eileen White, PhD, associate director for basic science at the Cancer Institute of New Jersey, and colleagues. They compared the global proteome (all of the expressed proteins) of Ras-driven cancer cells where autophagy was present to those where autophagy was deficient.

In this latest study researchers found that autophagy affects a majority of the proteins in Ras-driven cancers, yet the process is highly selective as to which proteins are targeted. For instance, investigators found that autophagy eliminates proteins involved in non-essential pathways or those deemed toxic under stressful conditions. Meanwhile, autophagy-resistant proteins involved in pathways needed for stress survival and autophagy maintenance were spared. The authors say these sets of proteins can serve as biomarkers for monitoring autophagy in the clinical setting. The study also revealed that defects in the autophagy process caused accumulation of certain proteins that prompted activation of an immune response in cancer cells and led to cell death.

“This remodeling process of the cell proteome by autophagy is an important immune-suppressive survival mechanism for Ras-driven cancers, and inhibiting autophagy can provide a means to target these aggressive cancers,” notes White, who is also a distinguished professor of molecular biology and biochemistry at Rutgers School of Arts and Sciences.

source : http://www.sciencedaily.com/releases/2014/08/140828135240.htm

Scientists map risk of premature menopause after cancer treatment

The findings, set out in the Journal of the National Cancer Institute, are based on the experience of more than 2,000 young women in England and Wales treated for the cancer over a period of more than 40 years.

Previous research has suggested that women with Hodgkin lymphoma who receive certain types of chemotherapy or radiotherapy are at increased risk of going through the menopause early — but there was insufficient information to provide patients with detailed advice.

But the new study, led by scientists at The Institute of Cancer Research, London, provides precise estimates of risk for women depending on which treatment types and doses they received and at what age — allowing doctors to give them detailed advice about their risks of future infertility.

The research was largely funded by Breakthrough Breast Cancer and involved researchers from across the UK at more than 50 universities and hospitals.

The research team followed-up 2,127 women who had been treated for Hodgkin lymphoma in England and Wales between 1960 and 2004, and who had been aged under 36 at the time. All had received treatment with chest radiotherapy, sometimes alongside other treatments.

Some 605 of the women in the study underwent non-surgical menopause before the age of 40. This was a large enough number for the researchers to estimate accurate risks of menopause at different ages, depending on the mixture and doses of treatments they received and the age they received them.

The researchers produced a risk table which could help improve the advice that clinicians are able to give to women who have undergone treatment for the disease. Several of the treatments caused a sharp increase in premature menopause risk.

For example, a woman who had received six or more cycles of a standard chemotherapy regimen in her late 20s, but without receiving radiotherapy to the pelvic area, had a chance of around 18 per cent of undergoing menopause by the age of 30, or 58 per cent by age 40.

Overall, risk of premature menopause was more than 20-fold raised after ovarian radiotherapy, and also after some specific chemotherapy regimens. Risk of menopause by age 40 was 81 per cent after receiving ovarian radiotherapy at an overall dose of 5 or more Grays, and up to 75 per cent after chemotherapy, depending on the type, although only one per cent after receiving a chemotherapy regimen called ABVD.

Study leader Professor Anthony Swerdlow, Professor of Epidemiology at The Institute of Cancer Research, London, said:

“Hodgkin lymphoma often affects younger women, and although fortunately most survive the disease, treatments including certain types of chemotherapy and pelvic radiotherapy can lead to premature menopause.

“We hope our study will help women to understand better, in consultation with their doctors, their risks of future infertility following treatment for this malignancy. By looking in a much larger group of women than previous studies of this type, we were able to produce age and treatment specific risk estimates that we hope will be of practical use to individual women. I’m extremely grateful to the patients and doctors who made it possible for us to produce this information.”

source : http://www.sciencedaily.com/releases/2014/08/140822094148.htm