The last few weeks have been hectic and I just haven’t had any energy at the end of the day to delve deep into science beyond what I’ve been writing for grants. The ebb and flow of work has been a lot of uphill ebbing lately, but all is well at the end of the day. I’m excited about a new project I am starting in lab looking at the role of some small RNA molecules in the metastasis of osteosarcoma. How fitting, since we are overdue to talk about another Hallmark of Cancer and we are up to Hallmark #6, which is “activating invasion and metastasis.” You can read about Hallmarks 1-5 in previous posts by clicking “Hallmarks of Cancer” in the categories or search for that term.
When I first explain the difference between cancer and not cancer to people, I generally explain that cancer has the biologic ability to spread to other places in the body, whereas things that are not cancer don’t have that ability. The overwhelming majority of deaths in cancer patients are due to disease that has spread elsewhere. For example, osteosarcoma, the bone cancer that I study, tends to spread to the lungs and respiratory failure is the number one cause of death in these patients. I know, it’s terrible stuff to talk about-but we have to do it so that we can figure out better treatment approaches. The real question is…how does a cell that started in the bone, escape its original space, bust into the blood stream, find its way to the lung and then know when and how to jump out of the blood stream, bust through the blood vessel and park itself in the lung? Further, once in the lung, a land as foreign as Mars to it…how does it thrive and grow to a point that it can overtake the lungs to the extent that the lungs can’t function? That whole process is what Hallmark #6 is about.
I’ve tried to think of multiple ways to explain this complicated process but have come up very short each time and it ends up being too technical. So here is my best attempt:
There are two major classifications of cells that make up tissues in our body. Epithelial cells are neat and orderly and tethered to each other. These types of cells make barriers in our body to protect it. The most obvious and largest epithelial tissue is skin. Mesenchymal (MEZ-INK-AH-MUL) cells are more loosely organized and can migrate throughout tissue and the body. Generally after development in a fetus, the only time cells like this are moving around are during wound healing…BUT..cancer cells have found a way to hijack the properties of mesenchymal cells and move around the body…but when they land in the lungs or elsewhere they switch back to a type of cell that doesn’t move! This Hallmark is an intense area of investigation and is highly complex. We have ideas of how this happens but there is so much more to learn. If we could figure this out for each cancer and then specifically target those cells that are moving around, then we would be able to cure a lot more patients.
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