Exploit What Nature Has Provided
Scientists have known that all primary tumors do not metastasize, but no one knew what prevented cancer's spread in these "metastasis incompetent" tumors. This new study was conducted to uncover that very mechanism.
"The novel idea was that if we can learn why these certain cancers don't spread, and then we could leverage that knowledge to block metastatic tumors," says Dr. Mittal.
Scientists don't understand why some tumors wouldn't "want" to spread. It goes against their "job description," says Dr. Mittal. He theorizes that metastasis occurs when the barriers that the body throws up to protect itself against cancer fail. But there are some tumors in which some of the barriers may still be intact. "So that suggests those primary tumors will continue to grow, but that an innate protective barrier still exists that prevents them from spreading and invading other organs," says Dr. Mittal.
What the researchers found is that, like typical tumors, metastasis incompetent tumors also send out signaling molecules that establish what is known as the "pre-metastatic niche" in distant organs. These niches comprised of bone marrow cells and various growth factors have been described previously by others including Dr. Mittal as the fertile "soil" that the disseminated cancer cell "seeds" grow in.
Weill Cornell's Dr. Ral Catena, a postdoctoral fellow in Mittal's laboratory and lead author of the Cancer Discovery study, found an important difference between the tumor types. Metastatic-incompetent tumors systemically increased expression of Tsp-1, a molecule known to fight cancer growth. Importantly, increased Tsp-1 production was found specifically in the bone marrow myeloid cells that comprise the metastatic niche. These results were striking, because for the first time the bone marrow-derived my
|Contact: Lauren Woods|
Weill Cornell Medical College