Protein found to control deadly cancer metastasis

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Researchers have found a critical element that may explain why some cancers spread farther and faster than others, a discovery that could lead to one of the Holy Grails of cancer treatment: containing the disease.

Scientists from the University of California, San Diego School of Medicine have identified a protein that seems to serve as a switch, regulating the spread of cancer from the primary tumor to distant spots in the body ? a process known as metastasis. The protein is used by embryo cells during early development, but then disappears from the body after an individual comes out of the womb.

According to the researchers, the protein was only found in people with metastatic cancer, leading them to belive that the regulation of this protein could potentially stop the dangerous progression of this killer disease.

?The protein seems to get turned off (after embryonic development), and we?ve only identified a small sub-population of cells that can turn it on,? lead investigator, Dr. Thomas Kipps, Evelyn and Edwin Tasch Chair in Cancer Research at UC San Diego, told FoxNews.com. ?By and large, we looked at the brain, lungs, heart, kidney and other organs, and it wasn?t there. Then we looked at a variety of cancers ? breast, ovarian, prostate ? and it seems to be a common theme to express this embryonic protein.?

Kipps said they stumbled upon this protein while conducting immunotherapy research on leukemia patients, in which they reengineered the patients? leukemia cells and injected them into their bodies. This technique is meant to enhance the body?s natural immune response to cancer.

?We did have patients respond to their leukemia cells, but part of the immune response was a cell that targeted (this protein),? Kipps said. ?Anecdotally, these patients did well. So we wanted to know (what) it is doing.?

The protein, called Receptor-tyrosine-kinase-like Orphan Receptor 1, or ROR1, is involved in a process known as epithelial mesenchymal transition (EMT), which occurs during early embryonic development. Throughout the EMT process, embryonic cells migrate and eventually grow into new organs.

Kipps explained that ROR1?s role during embryonic development may explain how it helps cancers to grow and spread.

?It?s a protein that sits on the surface of the cancer, so it has the ability to bind to other proteins outside of the cell and may have the ability to bind to other proteins on the cancer cell membrane,? Kipps said. ?Half of it sits outside the cell and half inside the cell. It?s like having an antenna sticking out, and then you have a transmitter below the surface. That transmitter conveys important signals to the cell, and it seems to allow itself to assume a better state of migration.?

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