Background: A cell that sloughs of the edge of a primary cancer in the breast has a tough road to survive. It has to break through the duct or lobule, cross breast tissue into a blood or lymph channel, swim, find a new organ in which to inject itself, and begin dividing (all while taking in sufficient nutrients and oxygen to stay alive).
Researchers from Howard Hughes Medical Institute found that loose cancer cells have a leg up on survival – genes they express to make them more likely to prosper in bone tissue. Whether the cancers cells turn on those genes depends on what their surroundings were like in breast tissue. If the breast tumor had molecular patterns similar to those found in the bone, it is more likely to survive.
My take: How exciting! This team previously found that by looking at breast cancer cell genetics, they could predict which ones were most likely to spread to bone. A set of genes called the Src response signature (SRS) was more often turned on in cells that metastasized to bone. But no one knew why the pathways got turned on in the first place. SRS didn’t help the cells to survive better in the primary site. Now biochemical experiments show that onlooker (mesenchymal) cells supporting a tumor have 2 genes activated (CYCL12 and IGF1) and produce a lot of cytokines (signalling molecules). The SRS gene signature makes cancer cells slightly more sensitive to these cytokines. Now, to make these findings actionable in the form of new drugs…
The bottom line? The environment of a primary tumor can give cancer cells varied abilities to lodge in other organs. This phenomenon might apply for other cancers and other sites of spread. Can we now develop drugs that affect the SRS pathway? I’m Dr. Michael Hunter, and that’s your science class for the day. Have a great one!
The small print: The material presented herein is informational only, and is not designed to provide specific guidance for an individual. Please check with a valued health care provider with any questions or concerns. As for me, I am a Harvard- , Yale- and UPenn-educated radiation oncologist, and I practice in the Seattle, WA (USA) area. I feel genuinely privileged to be able to share with you. If you enjoyed today’s offering, please consider clicking the follow button at the bottom of this page.
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References: http://www.sciencedaily.com/releases/2013/08/130829123439.htm; Cell (29 August 2013)