The Ohio State team wanted to see if the same occurred with other cancer cells.
They turned to cell lines Glaser had developed decades ago to study nasopharyngeal carcinoma (NPC), a serious, incurable head and neck cancer that occurs most frequently among people of Chinese descent.
They treated Glaser's cell line with norepinephrine and, as predicted, the cells all produced MMP-2, MMP-9 and VEGF. This showed that the receptors for this hormone were present on cells in Glaser's cell line, but that might have been just a laboratory aberration in the tissue cultures.
"We needed to see how relevant this finding was to what happened with actual tumors," he said. Glaser asked colleagues for samples of actual NPC tumors to look for the presence of similar receptors. They studied tumor samples which included different types of NPC tumors. All had the sought-after receptors.
"From this we can say that there is likelihood that all NPC tumors will have these receptors as well," he said.
"MMP-2 and MMP-9 contribute to the aggressiveness of these tumors," Yang said. "It isn't clear exactly how they are operating but they may work with VEGF to facilitate blood vessel growth in new tumors so that they can grow."
The target adrenergic receptors for these hormones are well-known to clinicians dealing with high-blood-pressure patients. Typically, such patients are given a class of drugs known as beta-blockers which lead to a lowering of blood pressure levels.
Glaser and Yang wanted to see how these same drugs affected these tumor cells. They added propanol, a beta-blocker, to the tumor cells and then exposed them to both norepinepherine and epinephrine. With the drug present, the levels of MMP-2, MMP-9 and VEGF didn't increase.
"This suggests a new approach to possibly fight some cancers ?the prescribing of beta-blocker-type drugs that would block these receptors and perhaps slow th
Source:Ohio State University