US researchers think they have found promising new molecular targets and treatment approaches for malignant brain tumours, suggesting a new therapy for anti-cancer drugs.
The research involved glioblastoma multiforme, the most common form of brain tumour and the least curable of all human cancers.
The first study identified a protein that seems to control the malignant features of brain tumour cells, suggesting a new treatment target for anti-cancer drugs. Researchers found that a little-known protein called Fra-1 was effective in controlling vascular endothelial growth factor D, a factor that promotes the growth of new blood vessels in most malignant brain tumours.
"This protein seems to be important in how tumours grow and how they may spread to healthy tissue," said Waldemar Debinski, director of the Brain Tumour Centre of Excellence at Wake Forest University Baptist Medical Centre. "It is a very powerful biological factor and may be an attractive target for anti-cancer therapy," he added.
The second study builds in earlier research by Debinski and colleagues that found that glioblastoma cells have a particular type of receptor for interleukin 13 (IL-13), a naturally occurring protein that regulates the immune system in the body. Normal cells do not have these same receptors. IL-13 is a very attractive target for molecular anti-brain tumour therapies and two clinical trials are currently ongoing.
The new study examined the role of proteins called cytokines in augmenting the amount of IL-13 receptor expressed by tumour cells. The use of these cytokines may improve treatment of glioblastoma cells by increasing the levels of IL-13 receptor in brain tumours and thus making them more accessible to drugs targeting the receptor.
The third research study focused on the search for novel specific molecular markers or targets in brain tumours. EphA2, a cell membrane-anchored protein-receptor, was shown to be uniformly over expressed in malignant brain tumours, but not in normal brain tissue.
"EphA2 represents a novel target for the development of molecular therapeutics for the imaging and treatment of patients with glioblastoma," said Debinski.