While the lion's share of funding for regenerative medicine is in the realm of first generation stem cell therapies and old-school drug discovery - aiming to take advantage of newly discovered biochemical cues that spur stem cells to particular actions - the prospect of bringing salamander-like regeneration to mammals is now attracting real interest. As a rule, public funding is far more publicized than the larger movements of private funding, so take this press release as indicative of the general state of research and fundraising in this field:
To some extent, humans already have the capacity for regeneration. For instance, certain cells, such as liver cells and red blood cells, can self-renew; and during embryonic development mammals and birds can regenerate such diverse tissues and structures as their skin and spinal cord. However, humans can't perform the same trick of regrowing a severed limb like salamanders or newts can. That is because in humans the cells that respond to the site of injury form scar tissue, whereas in salamanders the responding cells are genetically programmed to become the cell types of the lost structure, with full limb growth complete by two months.
When a salamander loses a limb, the wound sends out molecular signals that prompt surrounding tissue to begin production of new progenitor cells, also referred to as precursor cells. These progenitor cells continue to divide and form a large pool of cells at the wound site, called a blastema, that will later specialize and mature to help form the bone, muscle, cartilage, nerves and skin of the regenerated limb.
The researchers aim to prove that mammals can form the required progenitor cells for regeneration just as a salamander does. By studying salamanders and MRL mice, the researchers hope to identify the specific types of cells, molecular signals, genes and cellular scaffolding required for regenerative cell growth. In essence, they seek as comprehensive an understanding as possible of the mechanisms and processes - to obtain the blueprint for regenerative growth.
This is, as noted, a form of stem cell research. It has a lot in common with efforts to understand the process of cellular differentiation, in that it is thought that salamanders are dedifferentiating their cells in some way to produce progenitor cells. This fits nicely in with the thought that cells are really finite state machines, and the right keys can unlock all sorts of transformations in any cell - this may or may not be the case, but it would be very good for the future of medicine (and all of us) should it be so.
As for the past decades of cancer research, one of the greatest long term benefits to come from stem cell research will be a greatly increased understanding of human cellular biochemistry. Once you have the map, all journeys become that much easier.