Over the past two weeks, there has been much talk on social media and via the air waves on stem cells and regenerative technology. This has given me an opportunity to update my knowledge base regarding this form of therapy as I endeavour to get a better understanding of the program’s strengths and weaknesses and the opportunities and threats that we must face.
Interestingly, two years ago, I did a lecture at the UWI Open Campus for the Ripple Institue on “The Secret to Healthy Ageing” in which stem cells was shown to be pivotal to the renewal of tissue that have been damaged by injury and are important for the maintenance of the integrity of the body.
All life as a matter of fact start off when a sperm fertilises an egg (oocyte) and the resulting product then starts to divide. Up to the eight cell stage, it is called a morula at which time if the collection of cells are separtated, each can form a total organism. It is when this happens that identical twins and triplets are formed. At the blastocyst stage, the cells differentiate and a collection of cells called the inner cell mass are able to differentiate into many tissues of the organism. The embryo’s continued development is usually sacrificed for these embryonic stem cells, and the issue of its use is surrounded by much controversy as ethical and moral issues abound.
After the organism is formed and begins to grow, then each organ has stem cells that are resident in the tissues themselves and also reserved in the bone marrow which are called upon when needed to differentiate during the normal turnover and maintenance of cells of the tissues and organs. These are called the adult stem cells, and because many are not differentiated, they can be coaxed to differentiate into different tissues if removed from one part of the body and injected into another part. For example, fat stem cells may be able to be removed, cultured with the different growth and differentiation factors outside of the body, and be able to be converted into a heart muscle, or cartilage tissue. This is the least controversial aspect of stem cell research and it has huge potential, and is able to remedy deficiencies in cases of organ and tissue transplant shortages which is chronically limiting. Also, it would obviate the need for lifelong anti-rejection drugs which are expensive and also carries with it some untoward side effects. Each organ has a different rate of turnover and each molecule and cell of the organ are totally renewed via different time scales as shown below.
Finally, there is umbilical cord blood which carries stem cells itself, called mesenchymal stem cells, but its plasma is also rich in growth and differentiation factors that can also stimulate the body’s own adult stem cells to grow and differentiate, and there are currently trials being performed to determine their efficacy and safety. Here is an example of one that is registered at ClinicalTrials.gov: Clinical Trial to Evaluate the Potential Efficacy and Safety of Human Umbilical Cord Blood and Plasma.
So stem cells are either used directly from embyos, adult tissues, umbilical cord blood, or indirectly from cord blood plasma where growth factors are used to stimulate the body’s own adult stem cells. This falls under the general category of stem cell therapy or regnerative medicine. (Please see: https://en.wikipedia.org/wiki/Regenerative_medicine)
As an aside, one of our own, the late Dr Allan Sommersal had been involved in stem cell research, but his research is based on finding natural substances that are able to release our own adult stem cells from our bone marrow (the factory of our blood cells and also other stem cells) and he focuses less on isolating stem cells and the growth factors and more on stem cell nutrition. (Please see: Dr. Allan Somersall’s amazing speech from the 2013 North America Convention, held in Long Beach, CA!) The following images were adopted from his company’s website at stemtech.com.
As is evident from above, there must be open channels of communication between the tissues and the bone marrow, and the integrity of the circulatory system is vital to ensure that signals can be sent from the administrative branch of the tissues at the top to the technocratic branch of the bone marrow below to release the stem cells, and also to direct the movement of the stem cells from the bone marrow so that they are able to home in to the right tissue that is in need of repair. Conditions like diabetes, hypertension, obesity and high cholesterol occlude the large and small vessels of the circulatory system and as a result compromise the integrity of the tissues in two ways: 1) by restricting the nutrition of the organs and hence causing injury, and 2) by preventing the mobilisation of the messengers from the injured tissues to the bone marrow that are respondible for releasing the stem cells and guiding them to where they need to go.
Also, we are exposed to many toxic persistent organic polutants that not only destroy our cells and comprimise our tissues but negatively affect the functioning of our stem cells. Since the diseases mentioned above are lifestyle and environmental diseases which fundamentally are socially, economically and politically determined, it behooves us to reexamine our social, economic and political rules of engagment to reduce and mitigate their negative impact on the integrity of our circulatory system and the ennvironment in which our cells, tissues and organs operate, and also the bone marrow within which our adult stem cells are able to to thrive and be mobilised when needed.
Finally, although we have dealt with our normal stem cells during growth and development, there is another category of stem cells that are deserving of attention that is very much underappreciated, and that is the cancer stem cells. A recent article in the New York Times highlight the risks of stem cell research without taking heed of this real and present danger. (Please see: A Cautionary Tale of ‘Stem Cell Tourism’ , Athletes’ Use of Unproven Stem Cell Therapies: Adding to Inappropriate Media Hype?, Don’t market stem-cell products ahead of proof.)
Fortunately, we have another system besides the circulatory system that is responsible for detecting cancer cells and other foreign invaders and are able to keep these rogue cells from doing damage to the politics of our body. The are trained to determine which of our cells belong to the self and which are foreign invaders, like bacteria, virus and fungi, and which are self-cells that have gone rogue, like cancer cells, identify them and rid them from our body. If they are not able to eliminate them, or keep them in equilibrium, then they are able to escape from the clutches of the immune system and do lots of harm as they progress. This constant battle between the immune system and cancer stem cells can be tipped towards escape if the growth factors used in, lets say, cryoprecipitate from umbilical cord plasma, tips the balance in favour of the cancer stem cells, than the normal stem cells that the growth factors were intended for in the first place.
Signaling Interactions in the Tumor Microenvironment during Malignant Progression
(Upper) The assembly and collective contributions of the assorted cell types constituting the tumor microenvironment are orchestrated and maintained by reciprocal heterotypic signaling interactions, of which only a few are illustrated.
(Lower) The intracellular signaling depicted in the upper panel within the tumor microenvironment is not static but instead changes during tumor progression as a result of reciprocal signaling interactions between cancer cells of the parenchyma and stromal cells that convey the increasingly aggressive phenotypes that underlie growth, invasion, and metastatic dissemination. Importantly, the predisposition to spawn metastatic lesions can begin early, being influenced by the differentiation program of the normal cell-of-origin or by initiating oncogenic lesions. Certain organ sites (sometimes referred to as “fertile soil” or “metastatic niches”) can be especially permissive for metastatic seeding and colonization by certain types of cancer cells, as a consequence of local properties that are either intrinsic to the normal tissue or induced at a distance by systemic actions of primary tumors. Cancer stem cells may be variably involved in some or all of the different stages of primary tumorigenesis and metastasis.
Hence it is important to preserve the integrity of this system of checks and balances, as if they are taken for granted, these anti-self cells, be they viruses, bacteria, fungi or cancer cells, can compromise the smooth functioning of the tissues and disable the life-capacity of the person. Hence it is important to steward as best as we can our lifestyle choices and environmental exposures to ensure that our channels of communication (our circulatroy system) and our surveillance system of checks and balances (immune system) are not compromised but optimised to enable life to its fullest. (Please see: What our immune system can teach us on how best to organise socially, Exposing and Staging the Social Cancer in our Midst, No longer taking for granted this most precious gift of life and FROM INTEGRITY IN PLUMBING LIFE TO FREEDOM OF BLOOD FLOW – REGAINING CONFIDENCE IN OUR CIRCULATORY SYSTEM).
I hope that you can read between the lines, and help turn a negative into a positive, and use the last two weeks as a teaching point to understand what stem cell and regnerative medicine is all about, raise the level of our discourse to a higher level and generate more light than heat, and take away form this exposition what stem cells can teach us about civic life.