Experiments can lead to new treatments for neuroblastoma


17/08/2008

Neuroblastoma - one of the worst diagnoses that can deliver a baby. The average age of the victims of cancer is 2 years. At this age, most often detected in tumor abdominal child. But by the time the disease has time to develop to a stage at which death occurs in 50% of children, despite aggressive treatment with surgery, chemotherapy and radiation.

But scientists at the University of Texas Medical Branch at Galveston (University of Texas Medical Branch at Galveston) believe they have found a critical weakness of the deadly cancer - something that can lead to life-saving therapy.

A team of researchers led by Professor Chang Dai surgery (Dr. Dai H. Chung) conducted a series of animal experiments that demonstrate how shutting down a single biochemical signaling connection dramatically suppresses neuroblastoma tumor formation and slows the spread of cancer.

Their research focused on intercellular signaling molecule, known as gastrin-releasing peptide (gastrin-releasing peptide, GRP), and the receptor molecule with which it is docked on the cell surface. GRP activates the production of gastrin, a hormone that among other things controls the release of gastric acid in the stomach. Gastrin-releasing peptide is also produced neuroblastoma cells and acts as an accelerator of its proliferation (this discovery was made earlier by scientists at the University of the same).

"We have previously demonstrated that GRP stimulates the growth of this particular cancer - said Chung - At this time we wanted to demonstrate the opposite effect by acting on the GRP receptors in neuroblastoma. As a result, we wanted to see if it will help lead to the regression of cancer."

To "aim" in GRP, the researchers took a number of aggressive human neuroblastoma cells and added a short-hairpin RNA, tiny bits of genetic material specifically designed to prevent the cells to produce specific proteins, in this case - the receptor molecule GRP. Experiments with human neuroblastoma cells "plugged" receptors revealed that they grew much slower than the unmodified cells, and showed less activity in biochemical signaling pathway, which is associated with abnormal cell proliferation.

Scientists then cultured modified cells in soft agar, gelatin similar material in which cells can not attach to anything (the majority of cells to be fixed rigidly to multiply and form colonies, but neuroblastoma cells (such as cancer and other cells), live and multiply well in soft agar medium).

To grow and proliferate without being attached to the surface of cells in soft agar should have malignant properties as the original neuroblastoma cells. However, the cells with the "drowned" receptors behaved as benign cells, their growth was significantly inhibited, and they formed fewer new colonies.

To more thoroughly examine the effect of blocking receptor GRP, scientists conducted experiments with immuno-deficient mice. The researchers wanted to find out how these will behave neuroblastoma cells, whether they grow or metastasize. It was found that tumor growth was significantly reduced. In the control group of mice in which the cells were not changed, experienced rapid tumor growth and metastases in the liver aggressive. Most likely, the metastatic behavior of this type of cancer due to stimulation of gastrin-releasing peptide and its receptor.

Although researchers are still debating on the use of gene-modified cells as a potential treatment for patients with neuroblastoma and other cancers, a compound that blocks the receptor GRP, has been approved by the Food and Drug Administration (Food and Drug Administration, FDA, USA). Only the first news portal tells about the events of the day.

Original: Physorg.com


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