New tool to investigate the early stages of ovarian cancer

Cancer Research UK

Scientists in Japan may have found a way to unlock the 'black box' of early molecular changes that can lead to ovarian cancer.

The team's research, published today in the British Journal of Cancer, details the first human ovarian cell line capable of multiplying repeatedly in the laboratory without accumulating genetic damage.

The cell line will enable scientists to model the poorly understood initial stages of ovarian cancer more reliably. It is hoped this will help open up new avenues of research for the development of treatments and preventions. It may also offer clues that will help diagnose the disease earlier.

Ovarian cancer is one of the most difficult cancers to treat successfully, mainly because it is rarely caught early. There are no obvious symptoms and, unlike cervical, breast and bowel cancer, there is presently no proven effective screening programme that can catch the disease early or indicate pre-cancerous or early changes.

Each year in the UK 6,900 women are diagnosed with ovarian cancer. The majority of cases are diagnosed at a late stage, and five year survival rates are correspondingly low.

Until now, the human cell lines that researchers have used to model the progression of ovarian cancer in the laboratory have been of limited use because they quickly accumulate genetic damage that is unrepresentative of the development of the disease in patients.

To create the new cell line, the scientists injected healthy ovarian epithelial cells, with a virus containing proteins and an enzyme called telomerase. The proteins enabled the cells to divide repeatedly, giving the team five 'immortal' cell lines. When the lines were examined under the microscope, they found that, in the line called HOSE1-E7/hTERT, the telomerase had stabilised the cell chromosomes, preventing the accumulation of genetic damage.

One of the researchers, Professor Hidetaka Katabuchi, of the Faculty of Medical and Pharmaceutical Sciences, Kumamoto University, says: "Little is understood about the complicated molecular damage that takes place in the early stages of ovarian cancer because there hasn't been a reliable way to model the changes that occur.

"But our new cell line is like an aeroplane's flight recorder, or 'black box', recording all the damage for scientists to 'play back' and find out what has gone wrong."

Professor John Toy, Medical Director of Cancer Research UK, which owns the British Journal of Cancer, says: "It's heartening to make headway when investigating a disease like ovarian cancer which is difficult to treat successfully unless caught early. Hopefully, being able to model the progression of the disease in the laboratory more reliably will open up new avenues for earlier diagnosis and the development of more effective treatments."

ENDS

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Notes to Editor

British Journal of Cancer, Volume 93 Issue 1.

The healthy ovarian epithelial cells were removed, with consent, from a woman with endometrial cancer who had a hysterectomy.

A cell line is a supposedly genetically uniform population of cells derived from one individual, or it could be a clone (theoretically genetically identical descendants) of one original cell.

Screening for ovarian cancer in the general population - UKCTOCS

At the moment there is no screening programme for ovarian cancer in the general population. This is because the tests that are used in a screening programme have to be reliable and accurate. Doctors are not sure yet if the tests available at the moment are good enough to detect ovarian cancers early.

In the UKCTOCS trial, researchers are comparing 2 screening tests with no test at all. The women who have screening will either have a CA 125 blood test plus a transvaginal ultrasound scan, or a transvaginal ultrasound scan alone. These tests will be done on women who have been through the menopause.

The aim of the trial is to see if either of these tests will help doctors diagnose women with ovarian cancer when their cancer is at an early stage. If the tests work well enough it could mean that women with ovarian cancer may be diagnosed earlier, and their cancer treated more effectively.

Please note that it is not possible to volunteer to take part in this trial. Women are being chosen at random from Health Authority lists. If women are invited to take part, they will be contacted by post by the research team.

Ovarian Cancer

Ovarian cancer is the most common gynaecological cancer in UK women.

Each year almost 6,900 women in the UK are diagnosed with ovarian cancer, and more than 4,600 women die from it.

Ovarian cancer is the fourth most common cause of cancer death in women, accounting for 6% of all female cancer deaths.

Most cases of ovarian cancer are thought to arise from genetic damage to the layer of surface cells called ovarian surface epithelium (OSE).

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