Protein that helps cancer spread identified: study

Toronto: Scientists have identified a protein that enables the spread of tumours by binding cancer cells together and allowing them to invade tissues, paving the way for new therapies to treat the deadly disease.

The groundbreaking study identified a protein, known as cadherin-22, as a potential factor in cancer metastasis, or spreading. It decreases the adhesion and invasion rate of breast and brain cancer cells by up to 90 percent.

“Cadherin-22 could be a powerful prognostic marker for advanced cancer stages and patient outcomes,” said Jim Uniacke, from the University of Guelph in Canada. The study, published in the journal Oncogene, looked specifically at hypoxia – low-oxygen conditions – in tumours.

Researchers found that it is precisely under conditions of low oxygen that cancer cells trigger the production of cadherin-22, putting in motion a kind of protein boost that helps bind cells together, enhancing cellular movement, invasion and likely metastasis. Cadherin-22 is located on cell surfaces, allowing hypoxic cancer cells to stick together and migrate collectively as a group, Uniacke said.

Studying breast and brain cancer cells in a hypoxia incubator, Uniacke and his team discovered that cadherin-22 is involved in this process to enable the spread of cancer cells. “We found that the more hypoxic a tumour was, the more cadherin-22 there was in the area of the hypoxia,” Uniacke said.

“Not only that but the more cadherin-22 that there is in a tumour, the more advanced the cancer stage and the worse the prognosis is for the patients,” he said. For both cancer types, the research team used molecular tools to reduce the amount of cadherin-22.

They placed the human cancer cells into the incubator and lowered the oxygen to a level comparable to that in a tumour. The cells failed to spread. “One very powerful and common tool in cell and molecular biology labs is, you can remove a protein from a cell and see how that cell behaves without it,” Uniacke said.

“We culture our cancer cells in this very low-oxygen environment, and they start behaving like they are inside a low-oxygen tumour,” Uniacke added.