Publications | Diamond News Autumn 2009

Diamond News Autumn 2009

The role of zinc in breast cancer

sample of breast tissue
Measuring 400x400 microns (0.4mm2), this shows high levels of zinc in tumour regions, as indicated by the darker areas. The noncancerous tissue shows normal zinc levels, as indicated by its lighter colour.
Synchrotrons are increasingly playing an important role in health related research as the number of experimental techniques that can be used to move medical science forward grows and researchers become more aware of what they can achieve on the beamlines at Diamond, and at other light sources around the world.

Cancer is clearly one of the top priorities for research as each year 10.9 million people worldwide are diagnosed with the disease. In the UK, the most common cancer is breast cancer and it is the leading cause of death for women aged 34 to 54.

A team of researchers from Canada and the UK has been using Diamond’s Microfocus Spectroscopy beamline (I18) and two synchrotrons in Germany (ANKA and DESY) to study the distribution of zinc in tissue samples from patients with breast cancer.

Prof. Farquharson, from McMaster University in Ontario, explains the background to the research.

“While zinc is an essential element for life, and has been established as being of significant importance in humans, an excess can be toxic to cells. Hence the regulation of cellular zinc levels is of great interest to medical scientists. Our experiments made use of microprobe X-ray fluorescence facilities and we studied 59 samples, which were prepared to enable high throughput and allow us to correlate the distribution of trace metals with tumour cell distribution and important biological variables.”

Prof. Farquharson, McMaster University, Ontario

Oestrogen is a primary female sex hormone that acts by binding and activating protein molecules called oestrogen receptors (ER). Oestrogen is important for the normal growth and development of the mammary gland, but it also influences breast cancer progression. The tissue samples in the study were divided into two classes, oestrogen receptor positive (ER+ve) and oestrogen receptor negative (ER-ve) and the mean levels of zinc in the ER+ve tumour areas were found to be approximately 80% higher than the mean ER-ve levels. However, the non-tumour tissue regions of the samples contained on average the same levels of zinc in both types of breast cancers.

So what conclusions can be drawn from this work? Prof. Farquharson says, “Our method and results show for the first time the relationship of zinc in breast tumours to breast tumour biology. It opens the way for further investigations of the mechanism of zinc uptake in clinical samples and assays to select and monitor zinc chelation therapy, which is a possible treatment for the subgroup of patients with high tumour zinc levels. It is clear from this, and previous research, that zinc plays an important role in the development of breast and possibly other cancers and it is an element that warrants further study.”

Prof. Farquharson and his colleague will be back at Diamond for a follow up study in November 2009.

Zinc presence in invasive ductal carcinoma of the breast and its correlation with oestrogen receptor status. M J Farquharson, A Al-Ebraheem, K Geraki, R Leek, A Jubb and A L Harris 2009 Phys. Med. Biol. 54 4213-4223 2009
DOI: 10.1088/0031-9155/54/13/016

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