The discovery of stem cells only in the larger salivary gland ducts could revolutionize head and neck cancer treatment.

Stem Cells in Head and Neck Cancer

Treating head and neck cancer with radiotherapy can lead to serious loss of salivary gland function with the only current method of reducing such adverse effects being the lowering of the dose of radiotoxic therapy given. The problem with such a method is that the dose has to be substantial enough to treat the cancer and so lowering the dose may not offer the best course of treatment for patients in the long-run. Instead, researchers are now looking at the use of precise targeting of radiotherapy in order to spare substructures in the salivary gland, especially as they have observed an uneven distribution of stem cells in the salivary gland tissue.

Stem Cells and Slaiva

Stem cells present in the salivary gland are responsible for regenerating damaged tissue but it turns out that they are clustered in the larger ducts of the gland and are not found in the general salivary gland tissue. This could allow physicians to apply radiotherapy treatment for head and neck cancer in such a way as to spare these larger ducts from the toxic damage and, therefore, allow more of the stem cells to remain in order to repair other areas of the gland.

Sparing Stem Cells for Xerostomia Reduction

The researchers first observed the uneven distribution of stem cells in animals, followed by studies on human tissue. Peter van Luijk, PhD, from University Medical Center Groningen in the Netherlands, noted that the concentration of the stem cells in the center of the ducts was twice as high with twice as much regenerative capacity. Animals used in stem cell research were found to have a generalized reduction in function of the salivary gland when radiotherapy was applied across this area. In contrast, those animals who had the stem cell-rich ducts spared during radiotoxic therapy had a loss of function only in the site of irradiation rather than across the whole gland.

3D-Modelling for Radiotherapy Treatment

Using CT scans of human patients with head and neck cancer, the scientists devised a 3D model for applying various doses of radiotherapy to correlate with those areas of the gland tissue responsible for most saliva production. Using the model to then create a way of sparing salivary gland stem cells rather than following the standard gland-sparing approach to radiotherapy meant that the scientists estimate that they could reduce by half the amount of radiotherapy the stem cell areas received. This also has the advantage of not needing to alter the dose to the rest of the gland or affect coverage of the cancerous area.

Xerostomia and Stem Cells

Projections suggest that this stem cell-sparing model could result in unaffected saliva production in head and neck cancer patients a year after radiation therapy, with the parotid gland spared. Such models are not proof of principle however and stem cell clinical trials would need carrying out on human patients to test the theory. The current technique of sparing the parotid gland entirely can create difficulties in achieving an optimum dose to the tumor itself, but this new understanding of the presence of stem cells in specific ducts in the salivary glands may significantly improve outcomes for head and neck cancer patients faced with the threat of xerostomia.

Reference

P. van Luijk, S. Pringle, J.O. Deasy, V.V. Moiseenko, H. Faber, H.P. van der Laan, S. Brandenburg, J.A. Langendijk, J. Wu, R.P. Coppes, ESTRO 31: European Society for Radiotherapy and Oncology 2012 Annual Conference: Abstract OC 167. Stem Cell Sparing Radiotherapy of Head and Neck Cancer to Preserve Salivary Gland Function, Presented May 10, 2012.

Radbod Darabi, MD, PhD. and Rita Perlingeiro, PhD. Stem cell researchers at the University of Minnesota.

iPSCs for Muscular Dystrophy

The stem cell researchers used induced pluripotent stem cells, rather than embryonic stem cells, derived from human skin cells and then manipulated these in the laboratory to form a rapidly dividing population of muscle-forming cells. This procedure would allow for the patient’s own cells to be used in the stem cell treatment, meaning that the stem cell transplant is unlikely to be rejected and that no embryos would be destroyed in the process of treatment.

Creating Skeletal Muscle with Stem Cells

This research is the first example of a stem cell study using human stem cells with a therapeutic purpose, previous research has always made use of mouse stem cells which led to questions over the applicability of the results to human patients. The University of Minnesota’s findings will likely lead to a number of clinical trials for muscular dystrophy using stem cell therapy as the latest research offers the proof-of-principle necessary to begin such a trial. Previous research has been obstructed by the difficulties faced by scientists in creating a large enough quantity of muscle progenitor cells to be therapeutic, leaving many muscular dystrophy sufferers with little hope of finding a stem cell treatment.

Animal Research to Human Research

The research, published in Cell Stem Cell, details a strategy for developing the requisite rapidly dividing population of skeletal myogenic progenitor cells from the iPSCs. Scientists at U of M were also the first to use embryonic stem cells from mice to treat muscular dystrophy but it is this new technique to produce muscle stem cells from skin cells that allows the researchers to look at moving into clinical trials for human patients with neuromuscular diseases.

Long-term Benefits of Stem Cell Transplants for Muscular Dystrophy

The stem cell transplants led to extensive muscle regeneration in the mice, with a resulting improvement in muscle function long-term. The mice with muscular dystrophy were given human skeletal myogenic progenitor cells developed using a process of genetic modification from two well-characterized human iPSC lines and an embryonic stem cell line with the PAX7 gene. The latter allowed the researchers to control the level of Pax7 protein needed to regenerate muscle tissue after damage. The study revealed a capacity to turn naive embryonic stem cells and the iPSCs into muscle-forming cells, giving them an efficient way to create sizeable populations of cells suitable for transplantation and treatment for muscular dystrophy using stem cells.

Restoring Muscle Tissue with Stem Cells

The stem cells transplanted into the mice appear to be much more effective in treating muscular dystrophy than human myoblasts previously used in such research and which did not persist after transplantation. The progressive degenerative nature of muscular dystrophy means that any stem cell therapy would need to address the underlying cause of the condition or be repeated time and again to regenerative damaged muscles. The long-term benefits of this latest stem cell therapy has many people feeling positive of a major breakthrough in muscular dystrophy treatment options. The technique currently uses a virus vector to bring about the genetic modification of the cells but the U of M researchers are looking into an alternative method prior to commencing human clinical trials for stem cell treatment of muscular dystrophy.

Stem cell-derived fibroids grew ten times bigger than those from main cell populations

Stem Cells ‘Go Wild’

Scientists working at Northwestern University Feinberg School of Medicine and Northwestern Memorial Hospital looked at human fibroid stem cells grafted into mice and observed a significant difference in the size of tumors resulting from the stem cell grafts and those of main cell populations. One of the researchers, Serdar Bulun, MD., who is the chair of obsetrics and gynaecology at the institutions, noted that the stem cell ‘loses its way and goes wild.’ Although stem cells only make up around 1.5% of the cells in the tumor but are the powerhouses behind the fibroids’ expansion.

Stem Cell Mutation and Tumor Growth

The specific stem cell mutation behind the fibroid growth is called MED12, with mutations of the MED12 gene recently noted in the majority of uterine fibroid tumors assessed by researchers. Knowing that this is the origin of the tumors, rather than a part of the process or an effect of tumor growth, could make a big difference in the treatments given to patients with uterine fibroid tumors. The tumors grow in response to steroid hormones such as progesterone, meaning that the hormonal changes of menopause play a role in the progression of these types of tumor.

Stem Cell Safety

In this study, the uterine fibroids originating from the stem cell population grew ten times larger than those tumors started from the main cell population, giving stem cell researchers an opportunity to see how the stem cells initiate and sustain tumor growth. Although the safety of stem cell therapy has been called into question many times, the pervading view of stem cells is as a force for good, the body’s healers, capable of regenerating damaged tissue. The discovery that stem cells cause uterine fibroid tumors may surprise many people but could, ultimately, lead to improved therapy for a widespread condition.

Reference

Masanori Ono, Wenan Qiang, Vanida Ann Serna, Ping Yin, John S. Coon, Antonia Navarro, Diana Monsivais, Toshiyuki Kakinuma, Matthew Dyson, Stacy Druschitz, Kenji Unno, Takeshi Kurita, Serdar E. Bulun, (2012), Role of Stem Cells in Human Uterine Leiomyoma Growth, PLoS ONE: Research Article, published 03 May 201210.1371/journal.pone.0036935

A quite peculiar use of embryonic stem cells has led some religious groups to urge a boycott of Pepsi, Coca Cola, and Campbell’s Soups products in recent months. Whilst rumors of there being embryonic stem cells in Pepsi remain unfounded it is being reported that these companies had employed a research group called Senomyx to conduct flavor-testing studies using cells derived from embryonic stem cell lines, thus angering pro-life groups and providing further fodder for those opposing stem cell research.

Why Use hESCs in Taste-Testing

The cells in question were allegedly used to test new drink ingredients in order to see if they produce particular protein reactions that would indicate favorable effects on the human palate. Such research could also be carried out using cells cultured from adult stem cells, cord blood stem cells, or other research methods, making it unclear as to why Semonyx would have opted for discarded human embryonic stem cells for the research. It is also unclear as to the degree of involvement that Pepsi and other companies had with the actual research methods used by the company they hired for the work.

Boycotting Pepsi – Right-to-Life Groups

A number of right-to-life groups have called for a full boycott of Pepsi’s products following the allegations about their research practices. The company has ended its contract with Semonyx however, but the public relations damage has already been done it seems and the religious right is talking up a storm about the companies involved. It could prove difficult for many to follow their lead however, as many Pepsi products are well-known and widely available brands that are seemingly unrelated to Pepsi itself. Boycotting Pepsi would mean no Mountain Dew, Sierra Mist, Gatorade, Propel, Pepsi and Diet Pepsi, Tropicana, Lipton Ice teas, Starbucks Frappucinos (bottled), and Aquafina water. The boycott is now looking at being extended to Kraft, Campbell’s, and Nestle, ironic given the existing boycott of many such major companies by liberals and democrats on the basis of their activities in developing countries and their perceived capitalist greed. For once, it may be that the left and right come together to boycott the same companies, just for different reasons.

Stem Cells in Food?

One of the unsettling things to come out of all this talk of stem cells in Pepsi’s food research is that some people have become convinced that the embryonic stem cells are actually in the food itself. There is absolutely no evidence of this occurring but that has not stopped Oklahoma considering a bill to outlaw the use of foetuses in food. The Oklahoma Senator, Ralph Storey proposed bill SB1418 banning the sale of products that are developed with or contain aborted foetal remains but this is yet to be passed into law.

Is Pepsi Using Stem Cells for Research?

Pepsi has issued a statement saying that they do not conduct or fund research using human tissue or cell lines derived from embryos or foetuses, but pro-life lobbyists are pointing to the use of a line of cells known as HEK-293 which originate from the kidneys of aborted foetuses in the 1970s. These cultured cell lines are made available to the National Institutes of Health, American Type Cell Culture, Corriel Labs, and so forth, meaning that they could be used by stem cell researchers for a variety of projects, including food research.

Embryonic Stem Cells in Food – Ordinary Business?

A Security and Exchange Commission report ruled that the use of these cells by Semonyx when conducting research for Pepsi would constitute ordinary business operations, further angering those opposed to the research. Pepsi Next is said to be performing well following its recent launch, and the possible use of the stem cell research in the development of the product has not had to be brought to the attention of shareholders due to the classification of the activity as ordinary business. It is doubtful whether many PepsiCo shareholders remain ignorant of the issue however, considering the degree of media coverage. Perhaps this is another example of how the everyday activities of a stem cell research scientist appear bewildering and frightening to those outside of the industry, whilst simply being a matter of routine to the researcher themselves.

Pepsi may have used embryonic stem cell-derived material to develop flavor enhancers in their products but it seems that no clear rebuttal or admittance is forthcoming. The nearly fifty year old cell lines are so far removed from the original aborted foetuses that much of the talk about boycotts, forced abortions, and the presence of foetal cells in Pepsi can probably be chalked up to fear-mongering rather than fact.

Stem cells could slow down or even reverse the degenerative processes of osteoarthritis in the knee.

The Royan Institute’s clinical trial (NCT01504464) into intra-articular injections of mesenchymal stem cells into the knee joints hopes to demonstrate the safety, and effectiveness, of stem cell treatment for arthritis of the knee, one of the most common causes of disability amongst the elderly.

Osteoarthritis Knee Pain

Osteoarthritis in the knee is the result of wear and tear over many years, rather than occurring due to an autoimmune reaction as is the case with rheumatoid arthritis. The cartilage in the knee degenerates and may thicken or tear, inflammation occurs, the joint becomes less stable and the body may respond by forming new bone or reshaping the bone in an attempt to restore stability. In some patients it is sufficient to reduce stress on the knees by limiting certain weight-bearing activities like jogging, along with the use of analgesics and anti-inflammatory medications to manage osteoarthritis pain. Where such conservative measures are insufficient to improve quality of life for arthritis patients, it may be that an artificial joint replacement surgery is considered, with a total knee replacement sometimes able to restore joint stability and slow down or halt degeneration of surrounding tissues.

How Stem Cells Could Help Osteoarthritis

Stem cell therapy for arthritis could provide an additional stage in treatment, allowing more people to avoid invasive knee surgery for longer. This Iranian stem cell research will use bone marrow-derived mesenchymal stem cells, injected into the knee joints of patients to try to lessen the pain and degeneration associated with severe knee osteoarthritis. Forty patients will be enrolled onto the study which is set to be completed by September this year, leaving a few weeks remaining for patients to enquire about being involved in the stem cell arthritis trial. Patients will have their own bone marrow harvested and the mesenchymal stem cells will be separated out, cultured in the laboratory, and then transplanted back into the patient at the site of the osteoarthritis.

The patients in the placebo group will receive a stem cell treatment injection six months after the first placebo injection, and the treated group will have a placebo injection six months after their first stem cell injection. Stem cells injected to the site of the damaged tissue are hoped to prompt the body’s own repair mechanisms to rebuild the degenerated cartilage, bone, and ligaments in the knee joint, restore the lubrication of the joint, and improve mobility whilst reducing inflammation and knee pain.

The Quality of the Trial Design

The trial is placebo-controlled, triple-blind, and randomized, offering the best kind of evidence of a treatment’s safety and merit. Patients, physicians, and those assessing the effects of treatment will remain unaware during the trial of the allocation of each patient into a treatment or placebo group. Patients will be assessed on physical function after two weeks, using the WOMAC osteoarthritis index to measure any changes from baseline (before the stem cell treatment). Pain experienced by the patients will also be measured using the Visual Analogue Scale two weeks after treatment, and secondary measures include an assessment at the three month mark of joint swelling, joint erythema, deterioration of joint function, and the incidence of allergic reactions. Patients will undergo radiological examination before treatment and at the six month mark, using MRI, as well as being physically assessed for joint function and mobility. An unfortunate consequence of the study design is that the long-term effects of the stem cell injections for knee osteoarthritis will not be able to be conclusively assessed as the control group also receives the stem cell therapy, making comparisons after six months mostly redundant.

Safety of Stem Cell Injections for Arthritis

Stem cell injections may offer an alternative to invasive knee surgery for arthritis.

Could bone marrow stem cells repair lost myelin in Multiple Sclerosis?

How the MS Stem Cell Trial Works

The patients in the study will all undergo brain and cervical MRI scans, along with a variety of other medical tests and quality of life questionnaires at one month, three months, six months, and twelve months after the stem cell treatment or placebo. Patients in the placebo group will also have their stem cells extracted but these will be frozen for six months and a sham cell medium without the cells injected instead. The trial design is double-blinded, removing the likelihood of either the participants or the investigators influencing the outcome based on perception. Patients in the control group will be given their stem cell injections six months after extraction with the stem cells frozen and stored during that time.

What is Multiple Sclerosis – and Why Might Stem Cells Help?

Multiple sclerosis is a multifocal inflammatory disease of the central nervous system, with a variety of proposed causes and mechanisms. Patients are often affected in their early to mid twenties although first signs of MS can be missed in otherwise healthy individuals. Depending on the type of MS, symptoms may progress slowly over time, may go into remission, or could lead to rapid loss of sensation, motor control, and cognitive deficits. An autoimmune reaction is the most commonly cited explanation for the symptoms of Multiple Sclerosis, with this dysfunction prompting a self-propelled destruction of the insulating myelin around nerve fibers.

Other theories as to the cause of MS symptoms include bacterial infection (with Lyme disease, for example), iron overload and free-radical damage, and chronic cerebrospinal venous insufficiency (CCSVI), although this has been largely discredited. A genetic predisposition to MS has been uncovered in recent years, which could help researchers target specific components of stem cell behavior in order to promote myelin repair. Once myelin has been stripped from the neurons it is almost always unable to regrow, making the loss of insulation and damage to nerve communication irreparable. The hope is that the regenerative powers of stem cells can prompt recovery of this lost myelin and reverse, or slow, symptom progression.

Current MS Treatments

Multiple sclerosis is a condition involving lesions or plaques in the brain itself and/or along the spinal cord. Inflammation around these lesions is thought to be responsible for the periodic symptoms associated with the disease, and some patients’ symptoms abate to some degree once inflammation is brought under control. As degeneration builds however, the disease progression can accelerate, with irreversible axon damage occurring. Immunosuppressant therapies can help reduce the severity of MS attacks, slow down disease progression, and even allow some patients to go into remission in terms of one or more symptoms. No treatment for MS exists however which effectively stops the progression altogether or restores the myelin lost to the disease.

Bone Marrow Stem Cells for Multiple Sclerosis

Bone marrow-derived stromal cells can affect the immune system (said to have an immunomodulatory effect) and aid neuroregeneration like neuronal stem cells, at least in the laboratory. This animal research involved the injection of such mesenchymal stem cells into animals with an induced MS-like disease (experimental autoimmune encephalomyelitis). The stem cells appeared to have a neuroprotective effect and their relative ease of availability, in comparison to neural stem cells, makes them an ideal candidate for stem cell therapy for MS. Mesenchymal stem cells are also unlikely to be rejected by the patient in receipt of their own cells, and they are thought to present a lower risk of malignant development upon implantation.

Expectations for the MS Stem Cell Therapy Trial

Patients will not only be assessed using diagnostic imagery to monitor lesion development, repair, or stasis, they will also undergo tests for cognitive effects of the treatment. Somewhere between 45% and 60% of patients with Multiple Sclerosis experience cognitive impairment, with memory deficits the most common such symptom. The Rao test is considered a good indicator of the cognitive status of patients with MS and this trial into stem cell therapy for MS will make use of such a test as a measure of secondary outcomes, after safety.

Eligibility for the MS Stem Cell Trial

Patients have been recruited for this clinical trial but the recruitment window remains open and the researchers are aiming to complete their active research by August 2012. To be eligible for the trial patients must be between 18-55 years of age, have had MS for two to ten years, and have experienced little benefit, if any, from immunomodulatory and cytotoxic drugs. As the clinical trial is the purview of the Royan Institute in the Islamic Republic of Iran, it is unlikely that US patients with MS will be involved in the research but the findings from the MS stem cell trial could help patients worldwide.

References

Connick, P., Kolappan, M., et al, Autologous mesenchymal stem cells for the treatment of secondary progressive multiple sclerosis: an open-label phase 2a proof-of-concept study, The Lancet Neurology, Volume 11, Issue 2, Pages 150 – 156, February 2012.

Royan Institute, Evaluation of Autologous Mesenchymal Stem Cell Transplantation (Effects and Side Effects) in Multiple Sclerosis, clinicaltrials.gov.

For many years it was thought that stem cells were found only in embryos and bone marrow but restrictions on research and scientific enthusiasm means that answering the question ‘where can you find stem cells?’ gives a vastly different response to just a decade ago. Stem cells are found in all multicellular organisms and are cells that can divide and differentiate into a variety of specialized cell-types. Stem cells can self-renew to produce further stem cells and are sometimes referred to as master cells. There are different types of stem cells, found in different tissues of the body, and the type of stem cell determines the degree to which the cells it creates can differ. The ‘potency’ of the stem cells can now be improved in the laboratory but in the body adult stem cells have a finite number of cell types that they can create, whereas embryonic stem cells are able to produce every type of cell needed to produce a living, functional being.

Embryonic Stem Cells

Embryonic stem cells are found in the inner mass of cells known as the blastocyst. It used to be that by extracting stem cells from this mass, the blastocyst would be destroyed. Methods of embryonic stem cell extraction that leave the blastocyst alive are now available, which has altered the way some stem cell research is conducted. Embryonic stem cells taken from the inner mass of the blastocyst are pluripotent, able to create all of the cell types in the human body. The cells found in the trophoblast, which is the outer layer of cells of the blastocyst, are totipotent, able to create all cell types including those that develop into the placenta and extraembryonic tissues. Embryonic stem cells were the focus of most stem cell research in the early years of this field of study, despite controversy over the use of discarded embryos. Now that stem cells have been found in adult tissue the debate has changed significantly.

Where Are Stem Cells in the Body?

Adult stem cells are found in a number of tissues in the body and there they act as a repair mechanism to replace damaged and dead cells and keep organs and tissues functional. Adult stem cells are found in many more tissues than previously thought, including in the brain and central nervous system, the heart, and in the liver, amongst other organs and tissues. The potency of the stem cells does vary between different cell populations with some being pluripotent (able to create many different types of cells), and some oligopotent, or unipotent, able to create a limited number of cell types, or just one type of cell, respectively.

Significant Stem Cell Sources in the Body

Bone marrow is, perhaps, the best known place that stem cells are found in the body and the types of stem cells located here are called haematopoietic stem cells as they can create specific types of cells. Harvesting stem cells from the bone marrow can be extremely painful and leave the donor open to infection, and it is likely that the use of bone marrow stem cells will decrease in the coming years as peripheral blood stem cells are easier to harvest and can be made to display similar characteristics to bone marrow stem cells. Fat cells are also a significant repository for stem cells in the body and extraction of these using liposuction is becoming a more common procedure.

Other Places You Can Find Stem Cells

Umbilical cord blood, placental tissues, teeth, skin, and even the eye are all places in which stem cells can be found. These stem cells display different properties and abilities to create divergent cell types and so the discovery of stem cell niches makes it easier for scientists to envisage stem cell therapy targeted at specific organs and tissues in the body. When neural stem cells were located, for example, this gave stem cell researchers a greater opportunity to study the behavior of such stem cells and consider extraction and use of these neural stem cells when, previously, other adult stem cells would have to have been turned into induced pluripotent stem cells (iPSCs) using complex laboratory techniques. Discovering stem cells in tissues usually regarded as medical waste, such as cord blood, the placenta, and extracted teeth, as well as tissues from living donors, means that the future of stem cell research and treatments based on stem cells looks bright.

Identifying stem cells has become easier as stem cell technologies have been developed over recent years. Answering the question ‘what is a stem cell?’ involves an understanding of the way that cells behave in the body, the laboratory, and after medical procedures. Simply, a stem cell is a cell with the potential to regenerate tissue over the course of a lifetime, be this new blood, bone, liver cells, neural cells, or other cell type, although the type of stem cell will define the spectrum of tissue types it can give rise to.

Haematopoietic Stem Cells

Haematopoietic stem cells are found in bone marrow and are able to produce new immune system cells and blood cells. Bone marrow transplants use the ability of these stem cells to repopulate the damaged immune system of patients with disease such as leukaemia. Stem cell treatments involve extraction of these bone marrow stem cells, followed by laboratory culture to increase the number of stem cells, and then injection into the recipient, often after they have had chemotherapy to destroy the dysfunctional cells in their own body. After a stem cell transplant it should still be possible, many years later, to isolate and identify the transplanted stem cells, showing that the stem cells were able to auto-renew over time.

Stem Cell Properties

Identifying stem cells can involve the use of clonogenic assays to uncover the stem cells’ ability to renew themselves and to differentiate into different cell types. Specific cell-surface markers have also been discovered that indicate the type of stem cells and their likely behavior in the body. However, the variation in environmental conditions in the laboratory and in the body, and even between different areas of the body, make it difficult to accurately predict the cells’ behavior. Laboratory techniques have been developed that allow physicians to take a stem cell programmed to produce just one or a limited number of cell types and induce pluripotency to allow it to give rise to any type of cell. Environmental cues can then be given to direct its differentiation, although the success of this signalling is still under investigation.

What Are Adult Stem Cells?

Adult stem cells are those found in the tissues and organs of the adult body and which are able to differentiate into other cell types to renew and regenerate bodily tissues. These undifferentiated cells can self-renew to maintain a stem cell niche out of which new cells are created to replace those damaged during ordinary metabolic processes or injury, disease, or other incident. This reparatory work is the primary role of adult stem cells and some scientists refer to these types of stem cells as somatic stem cells; where soma refers to the body, rather than eggs, sperm, or germ cells. Adult stem cells have been identified in a variety of tissues, many more than initially expected, and there is much excitement over the potential for adult stem cell treatments and research.

Bone Marrow Transplants and Stem Cells

The use of adult stem cells actually precedes much stem cell knowledge with physicians knowing that bone marrow transplants were successful in treating many cases of leukemia over the past forty years or so but unaware of the specific action of these types of stem cells in the transplant material. Stem cells have been found in the heart, lungs, brain, and liver, amongst other tissues and it is this ongoing discovery that makes many excited about the prospect of transplantation stem cell therapy for a variety of conditions.

There are an increasing number of potential stem cell treatments as we further understand what a stem cell is.

Other Types of Stem Cells

Embryonic stem cells are undifferentiated stem cells with the capacity to turn into all of the tissues of the body. This ability is what makes many researchers excited about their potential use in stem cell treatments and laboratory research. However, this very capability of divergence also prompts concerns over the development of unwanted cell types upon transplantation and so use of embryonic stem cells in a therapeutic capacity remains restricted in many countries at least until such time as the safety of emrbyonic stem cell transplants can be demonstrated sufficiently. Umbilical cord blood stem cells are haematopoietic stem cells similar to those found in bone marrow and offer a more readily available resource using material otherwise often considered simply to be medical waste. Concerns over cord colitis syndrome have emerged in recent months however, but many more people are receiving this type of stem cell transplant as part of clinical trials and for treatment of leukemia and other blood disorders. Stem cells taken from the placenta or Wharton’s Jelly in the umbilical cord are more akin to embryonic stem cells and so are able to differentiate into many more cell types than adult stem cells. Further research is being carried out into the potential uses of these stem cell sources. The question ‘what is a stem cell?’ continues to fascinate as stem cell researchers find out more about the potential of these cells to revolutionize modern medicine.

Trauma at birth, infection, or medications can cause hearing loss in children.

Cord Blood Stem Cells for Hearing Loss

A number of successful animal studies have been carried out using cord blood stem cells for hearing loss and scientists are now ready to move onto treating human patients with the experimental therapy. The animal trials showed that stem cells from cord blood, when transplanted into the inner ear of the subject, could improve inner ear function by promoting repair in the damaged tissue. Causes of hearing loss in infants can include direct trauma to the head during birth, viral infections, and even some medications given to mothers, or their babies, particularly when premature labor occurs. Sensorineural hearing impairment occurs as a result of structural damage to the inner ear or nerves connecting the ear to the brain. The cochlea, a snail-shell-shaped inner ear structure is the target of the stem cell therapy as this is where the tiny hair cells are found that are responsible for the electrical signals we process in the brain to perceive sound.

Who Can Take Part in the Stem Cell Trial?

Patients in the trial must have had their cord blood banked.

Stem Cell Procedures

The children included in the trial will have their own stem cells, taken from their stored umbilical cord blood, transplanted through an intravenous line as outpatients of the hospital. Otolaryngologist, Samer Fakhiri, who is leading the research, will conduct periodic assessments of the children to determine the extent, if any, of improvement in their hearing. The hope is that success in this stem cell trial will allow patients with hearing loss to avoid invasive surgical procedures and yet still recover a significant degree of hearing. A stem cell cure for hearing-loss is still in the distant future however, and this is just the first trial in children to be approved by the US FDA. In other countries, such as England, stem cell research into age-related hearing problems has looked at patients over sixty years of age in order to understand the mechanism behind loss of hearing. These researchers are now using stem cells to target the dysfunctional cells and it may be that international collaboration between stem cell scientists can help both young and old to recover hearing using stem cells.

Could Pluristem Therapeutics win the stem cell race to heart disease cure?

Stem Cells for Heart Attacks

The trial was carried out at the Center for Regenerative Therapies in Germany by Pluristem Therapeutics Ltd., and involved twenty mice being subjected to heart attacks before treatment. The company’s placental expanded cells (PLX) appear to have improved a number of cardiovascular parameters after acute myocardial infarction (MI) in the mice, with Professor Christof Stamm, the man leading the study, excited about the potential for heart disease treatment with stem cells.

Findings from the Pluristem Study

In order to assess the success of treatment, the mice were killed after four weeks and their heart tissue examined. Prior to their execution they had electrocardiograms (ECGs), as did five other mice who had a sham operation rather than the stem cell treatment or treatment with the cell-free medium. Unfortunately, the results from the study are not yet available except for the details given in the company’s press release and so scientists and patients alike are waiting for the researchers to write up their findings before assessing the likelihood of human clinical trials any time soon.

Stamm, et al, induced heart attacks in mice and then treated half with placental stem cells.

Promising Stem Cell Treatment for Heart Disease

Over 620,000 people suffer acute heart attacks each year in the United States, and the rise in diabetes, obesity, and the average age of citizens in the US all mean that this figure is likely to increase. Currently, once a person has suffered from one heart attack, the likelihood of another acute myocardial infarction is elevated and most patients are given medications to take daily along with lifestyle, and dietary modifications to lower their risks. Pluristem are all too aware that finding a successful treatment for ischaemic heart disease is a multi-billion dollar industry and that many pharmaceutical companies are looking for a piece of the market. The announcement of these results prompted a rise in the company’s share-price but it remains to be seen if human trials will go ahead and whether the success of the animal trials will be mirrored.

The Battle Over Stem Cell Therapy

Other researchers working on a protocol for stem cell treatment for ischaemic heart disease are viewed, in some circles, as having published their results prematurely, with the trial by Bolli, et al, only about half finished. These stem cell researchers consider it important however to publish their findings so far in order to expedite movement towards Phase II trials for cardiac stem cell treatment. They argue that, as their own trial will likely be completed, analyzed, and results published only in 2014, the length of time needed to set up another trial afterwards will only delay further the clinical application of stem cell treatments for heart attack patients. The danger is that, by publishing results halfway through a trial the long-term effects of the stem cell therapy are unable to be assessed and so costly pre-trial investigations may be made which then amount to nothing or send stem cell researchers in the wrong direction. It is certainly an exciting time for stem cell research into cardiovascular disease but the application of caution may be needed, especially considering the time, money, and lives involved.

References

Bolli, R., Chugh, A.R., et al, (2011), Cardiac stem cells in patients with ischaemic cardiomyopathy (SCIPIO): initial results of a randomised phase 1 trial, The Lancet, Volume 378, Issue 9806, Pages 1847 – 1857, 26 November 2011

Christof Stamm, Boris Nasseri, Roland Hetzer, Cardiac stem cells in patients with ischaemic cardiomyopathy, The Lancet, Vol 379, No. 9819, Mar 10th, 2012, pp.867-976, e34-35.