Sugar in cells marks esophageal cancer

NYU (US) — Researchers say it may be possible to detect pre-cancerous cells in the esophagus by identifying changes in the patterns of sugar molecules that line the cells.

The discovery, reported in the journal Nature Medicine, could it much easier to detect and remove these cells before they develop into esophageal cancer—the fifth biggest cause of cancer death in the United Kingdom and the eighth leading cause of cancer deaths for men in the United States, with the number of people diagnosed increasing rapidly.
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People diagnosed with the pre-cancerous cells, a condition known as Barrett’s dysplasia, are at an increased risk of developing esophageal cancer and need to be closely monitored to make sure the disease is not progressing.

Dysplasia offers a stage at which cancer can be prevented by removing these cells. However correctly identifying these areas has proved to be problematic, as they can easily be missed during endoscopy and biopsy, which only take samples from a small part of the esophagus.

This can result in false reassurance for patients in whom their dysplasia has been missed.

For the study, Lara Mahal, associate professor of chemistry at New York University and Rebecca Fitzgerald at the Medical Research Council in the UK discovered a new mechanism for identifying Barrett’s dysplasia cells by spraying on a fluorescent probe that sticks to sugars and lights up any abnormal areas during endoscopy.

By analyzing the sugars present in human tissue samples taken from different stages on the pathway to cancer—using microarray technology developed by Mahal, the researchers found that there were different sugar molecules present on the surface of the pre-cancerous cells.

The technology uses sugar binding proteins, known as lectins, to identify changes in sugars and pinpointed carbohydrate binding wheat germ proteins as a potential diagnostic. When the wheat germ proteins, attached to a fluorescent tag that glows under a specific type of light, were sprayed onto tissue samples, it showed decreased binding in areas of dysplasia, and these cells were clearly marked compared with the glowing green background.

“The rise in cases of esophageal cancer both in the UK and throughout the Western world means that it is increasingly important to find ways of detecting it as early as possible,” Fitzgerald says. “Our work has many potential benefits for those with Barrett’s esophagus who have an increased risk of developing esophageal cancer.”

“We have demonstrated that binding of a wheat germ protein, which is cheap and non-toxic, can identify differences in surface sugars on pre-cancerous cells,” she adds.

“And when coupled with fluorescence imaging using an endoscopic camera, this technique offers a promising new way of finding and then treating patients with the highest risk of developing esophageal cancer, at the earliest stage.”

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