One last stem cell related blog and I promise, I’ll move on to a new topic.
There have been some interesting articles in the science literature about the potential use of stem cells to treat cancer. This is based on basic research and is not yet used in any clinical trials or ready for prime time. It is an interesting idea that MAY show promise as a therapy someday but is NOT there yet. Therefore, I am not advocating that it should be sought out as a therapy now or that if this does exist anywhere it will be beneficial. Time will tell as more research is conducted if it is a good therapy or if some other therapy will come of out of this research.
Mesenchymal stem cells are cells found in the bone marrow. Actually, there are two types of bone morrow derived stem cells, hematopoetic (that go on to become white blood cells) and mesenchymal (that can differentiate into many cell types and are involved in wound/tissue repair). It also turns out that mesenchymal stem cells (MSC), because of their role in wound repair and tissue regeneration, migrate to cancer tumor sites. The current understanding is that tumor cells release agents called chemokines that attract MSCs to the site. The role of these MSCs within tumors is still largely unclear but it is thought that they may contribute to supporting tumor growth. Interestingly, scientists have been looking at how to use this migration capacity of MSCs to turn these cells into cells that deliver some form of therapy (aka a vector for cancer therapy). Basically, MSCs can be engineered to express a gene that will kill the tumor cells. For example, MSCs can be made to express the interferon beta protein and then used to target to melanoma tumors. Interferon beta has been shown to inhibit tumor growth by causing cells to stop growing and die.
The advantage of using MSCs instead of just injecting a drug or ingesting a pill is that MSCs could be better at targeting to a tumor site and reducing the unintended side effects by affecting non-tumor cells. This would be especially beneficial for tumors that are hard to access such a solid tumors in the breast, etc...
As I said at the beginning of this piece, this is a test of a theory that is being investigated. It is a very attractive idea, to use cells that preferentially go to tumor sites as a method to deliver therapy. There is still a lot that isn’t known yet, like will the MSCs themselves promote tumor growth? For now, it is a novel way to deliver therapy directly to the tumor site. Hopefully, this research will continue to progress.