Recorded: 03 Jun 2016
Well, there’s a lot of problems that really are not well resolved in the area of cancer metastasis. One question is ‘What is the precise nature of the cancer stem cells?’ We know they are connected somehow with the EMT program, we know that they lie somewhere halfway between the epithelial and mesenchymal state, but we don’t know exactly where they are. We’ve never been able to isolate pure populations of cancer stem cells, so we don’t know all of the characteristics and that’s an ongoing challenge. A major problem that we’re not working on is the following: I think in the case of carcinomas, I think in the case of carcinomas that the EMT program is powerful enough to empower the cell from a primary tumor to migrate to this tissue. It has all those traits that are required and ordered to disseminate - to spread. However, the big problem, the big unsolved problem - which I think is going to be very complicated to solve, is to figure out how cancer cells once they arrive at a distant tissue, figure out how to make a living. Because a breast cancer cell is poorly adapted to proliferate in the brain or the liver or the bone marrow or the lungs, because after all it knows how to grow in the mammary gland, why should it be able to grow in these distant tissues? And how that happens and what kind of adaptations the breast cancer cell needs to make after it makes that long voyage is something we don’t really understand - it’s an abiding mystery and it could be a very complicated one, in terms of its solution, which contrasts with what I’ve told you about the process of physical spreading, of dissemination because it seems to me that the problem of metastatic dissemination of carcinoma cells - how they move from one site to another can be solved and explained in the context of the EMT program that I’ve referred to. But, what we don’t know is the much more challenging problem of how cancer cells figure out to make a living after the EMT program has carried them to the distant tissue.
Robert "Bob" Weinberg is Daniel K. Ludwig Professor for Cancer Research and director of the Ludwig Cancer Center at MIT, an American Cancer Society Research Professor, and is a founding member of the Whitehead Institute for Biomedical Research.
In 1982 he was one of the scientists to discover the first human oncogene, Ras, which causes normal cells to form tumors, and his lab also isolated the first known tumor suppressor gene, Rb.
He co-authored with Douglas Hanahan the landmark "Hallmarks of Cancer" paper in 2000, which laid out the six requirements for a healthy cell to become cancerous.