Small vessels help cancer cells

Small blood vessels associated with brain tumours create a nurturing environment for self-renewing cancer stem cells, US researchers report.

They also found that antiangiogenic drugs that disrupt this environment reduce the number of cancer stem cells and halt tumour growth.

Cancer stem cells comprise only a small fraction of most brain tumours but play a critical role in tumour growth and survival, according to background information in the study, published in the January issue of the journal Cancer Cell.

Researchers at St. Jude's Children's Research Hospital in Memphis found that cancer stem cells in human brain tumours are associated with blood vessels and that, in culture, vascular cells interact with and help brain cancer stem cells survive. This kind of interaction was not seen in most kinds of non-cancer stem cell tumour cells.

The researchers also transplanted human brain tumours, with or without vascular cells, into mice. The mice that received the vascular cells showed an increase in cancer stem cells and increased tumour activity.

Tumour growth halted in mice
When the mice were given antiangiogenic drugs to diminish tumour blood vessels, the team saw a reduction in cancer stem cells. Tumour growth was also halted, the study authors said.

"Our data identify a possible role for niche microenvironments in the maintenance of CSCs (cancer stem cells) and identify a mechanism by which antiangiogenic drugs inhibit brain tumour growth," researcher Dr Richard J. Gilbertson said in a statement. "If the notion that niches protect CSCs proves correct, then targeting these microenvironments could prove highly effective treatments of cancer." – (HealthDayNews)

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A-Z of Brain tumour

January 2007