Stem Cell Research

Video: Drug Discovered That Destroys Human Cancer Stem Cells But Not Healthy Ones

The drug thioridazine apparently kills cancer stem cells in humans while avoiding the toxic side-effects of conventional cancer treatments.

"The unusual aspect of our finding is the way this human-ready drug actually kills cancer stem cells by changing them into cells that are non-cancerous," said Mick Bhatia, scientific director of McMaster University's Stem Cell and Cancer Research Institute in the Michael G. DeGroote School of Medicine.

Unlike chemotherapy and radiation, thioridazine appears to have no effect on normal stem cells. The research team has identified another dozen drugs that have good potential for the same response.

 

Successful Integration Of Embryonic Stem Cells Into Spinal Cord Reduces Neuropathic Pain

The findings suggest avenues for clinical strategies aimed at correcting the underlying disease pathology as opposed to treating the symptoms of chronic debilitating pain.

"Pharmacological approaches to managing neuropathic pain enhance GABA-mediated inhibition. However, some patients do not respond to these therapies and there are significant adverse side effects," said Dr. Allan Basbaum from the University of California, San Francisco.

There are two major classes of chronic pain: inflammatory pain that results from injury to tissue, such as muscle and bone, and neuropathic pain from injury to nerves, for example, in the limbs or face. Damage to nerves can occur after physical trauma and from chemotherapy drugs. With neuropathic pain, the pain occurs in the absence of stimulation, and there is hypersensitivity and exacerbated pain to stimuli that would not normally cause pain.

Single Stem Cell Mutation Triggers Fibroid Tumors

Researchers have identified the molecular trigger of the uterin fibroid tumor, a single stem cell that develops a mutation, starts to grow uncontrollably and activates other cells to join its expansion.

The stem cell initiating the tumor carries a mutation called MED12. Once the mutation kicks off the abnormal expansion, the tumors grow in response to steroid hormones, particularly progesterone.

"No one knew how these came about before," said Serdar Bulun, M.D., chair of obstetrics and gynecology at Northwestern University Feinberg School of Medicine and Northwestern Memorial Hospital. "These stem cells

Osiris Therapeutics Prochymal, A Mesenchymal Stem Cell Product Derived From Bone Marrow, Approved For Marketing In Canada In Graft vs. Host Disease (GvHD)

Prochymal has been authorized for therapy in children with GvHD under Health Canada's Notice of Compliance with conditions (NOC/c) pathway, which provides access to therapeutic products that address unmet medical conditions and which have demonstrated a favorable risk/benefit profile in clinical trials. Under the NOC/c pathway, the sponsor must agree to carry out confirmatory clinical testing.

Both Osiris (OSIR) with Prochymal and Athersys Inc. (ATHX) with Multistem are in clinical trials with allogeneic GvHD stem cell therapies in the United States. Osiris concentrated on children after some issues arrose in its phase II clinical trial and has been aided in data presentation to Canadian authorities by Joanne Kurtzberg of Duke University. Athersys has not yet begun Phase II but has completed Phase I with good results.

Video: UC Davis On The Research And Therapeutic Value Of Cord Blood Stem Cells

A good summary of the research and therapeutic possibilities of cord blood presented by UC Davis as part of its Stem Cell Dialogues series. Taking place in late June of last year it forms a solid basis for posts we will be including as advances take place. The presentation includes three UC Davis faculty members, including UC Davis Institute for Regenerative Cures Director, Jan Nolta, along with cord-blood experts Suzanne Pontow and Jon Walker. This presentation was to announce California legislation creating a state-wide public stem cell bank. As far as we can determine, the funding for this is currently being held up by budgetary concerns at the State level.

 

Dr. Joanne Kurtzberg of Duke University has been a pioneer in the therapeutic application of cord blood stem cells in childhood diseases, in particular Cerebral Palsey.

 

Gene-Modified, Transplanted Blood Stem Cells Protect Brain Cancer Patients From Toxic Side Effects of Chemotherapy

Initial  results of the ongoing, small clinical trial of three patients with  glioblastoma showed that two patients survived longer than predicted if they had not been given the transplants, and a third patient remains alive with no disease progression almost three years after treatment.

“We found that patients were able to tolerate the chemotherapy better and without negative side effects after transplantation of the gene-modified stem cells than patients in previous studies who received the same type of chemotherapy without a transplant of gene-modified stem cells,” said Hans-Peter Kiem, M.D., a member of the Clinical Research Division at the Fred Hutchinson Cancer Center.

A major barrier to effective use of chemotherapy to treat cancers like glioblastoma has been the toxicity of chemotherapy drugs to other organs, primarily bone marrow. This results in decreased blood cell counts, increased susceptibility to infections and other side effects. Discontinuing or delaying treatment or reducing the chemotherapy dose is generally required, but that often results in less effective treatment.

Communication Between Stem Cell Derived Motor Neurons, Muscle Cells Measured

Researchers have developed a novel system to measure communication between stem cell–derived motor neurons and muscle cells in a Petri dish.

In a proof of principle, they have shown that functional motor circuits can be created outside the body using stem cell–derived neurons and motor cells, and that the level of communication, or synaptic activity, between them can be accurately measured by stimulating the motor neurons with an electrode and then tracking the transfer of electrical activity into the muscle cells to which the neurons are connected.

When motor neurons are stimulated, they release neurotransmitters that depolarize the membranes of muscle cells. This allows calcium and other ions to enter the cells, causing them to contract. By measuring the strength of this activity, one can get a good estimation of the overall health of motor neurons.

The estimation could shed light on a variety of neurodegenerative diseases, such as spinal muscular atrophy and amyotrophic lateral sclerosis (Lou Gehrig's disease), in which communication between motor neurons and muscle cells is thought to unravel, said, Bennett G. Novitch, an assistant professor of neurobiology and a scientist with the Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research at UCLA.

Human Pluripotent Stem Cells Change During Expansion And Differentiation In Ways Not Easily Detected

Last year this research team reported recurrent changes in the genomes of human pluripotent stem cells as they are expanded in culture.

Now they have shown that these cells can also change their epigenomes, the patterns of DNA modifications that regulate the activity of specific genes—sometimes radically. These changes may influence the cells' abilities to serve as models of human disease and development.

"Our results show that human pluripotent stem cells change during expansion and differentiation in ways that are not easily detected, but that have important implications in using these cells for basic and clinical research," said Louise Laurent, assistant professor in the University of California San Diego School of Medicine.

Many avenues of stem cell research focus on determining how genes are turned on and off during the course of normal development or at the onset of a disease. It is widely accepted that gene activation and silencing play important roles in transforming all-purpose stem cells into the specific adult cell types that make up the specialized tissues of organs such as the heart and brain.

Here, Louise Laurent and Professor Jeanne Loring of Scripps Research focused on understanding gene silencing via DNA methylation, a process whereby bits of DNA are chemically marked with tags that prevent the genes from being expressed, effectively switching them off. Errors in gene silencing via DNA methylation are known contributors to serious developmental defects and cancer.

Specifically, they assessed the state of both DNA methylation and gene expression in the most comprehensive set of human stem cell samples to date, comprised of more than 200 human pluripotent stem cell samples from more than 100 cell lines, along with 80 adult cell samples representing 17 distinct tissue types.

How Embryonic Stem Cells Orchestrate Human Development

New research shows in detail how three genes within human embryonic stem cells regulate development.

Researchers have identified three genes active in early development — Nanog, Oct 4, and Sox 2 — as essential to maintaining the stem cell’s ability to self-renew and prevent premature differentiation into the “wrong” type of cells. Because of restrictions on the use of human embryonic stem cells, much of the investigation into how these genes work has been done in mice.

“It is difficult to deduce from the mouse how these cells work in humans,” said Natalia Ivanova, assistant professor of genetics in the Yale Stem Cell Center. “Human networks organize themselves quite differently.”

Video: Stem Cell Therapeutic Solutions For Non-Healing Bone Fractures

Perhaps the area with the most promise for economic stem cell therapies in the near term is the healing of difficult fractures, a market where existing procedures total around $100 billion per year in the U.S. alone. Severe bone fractures can lead to such massive bone loss that realigning and fixing the bone with implants is not enough to heal the bone. In these cases, the trauma victim is left with chronic pain and non-functioning limbs.

In this video, Dr. Mark Lee, an orthopedic surgeon at the UC Davis School of Medicine, discusses new stem cell based methods to overcome these current challenges in treating non-healing bone. Techniques discussed are based on the use of mesenchymal stem cells. This took place on March 21, 2012.

 

New Research Shows How Stem Cell Therapy Keeps the Immune System Under Control

Recent studies have shown the benefits of administering Mesenchymal Stem Cells (MSCs) to patients with immune-related disorders such as graft versus host disease, systemic lupus erythematosus, rheumatoid arthritis, and more.

The MSCs appeared to quell the production and function of overactive immune cells, including T- and B-lymphocytes. However, the specific mechanism behind how MSC get the immune cells under control hasn’t been fully understood.

New Method Found To Improve Stem Cell Delivery

It turns out that delivery of transplanted stem cells to a specific site in rodents is improved by increasing the presence of chemicals that attract the introduced cells.

Non-destructive pulsed and focused ultrasound interacts with tissue to elevate levels of naturally produced chemicals (such as cytokines, chemokines, and growth factors) on target tissues. Transplanted stem cells have receptors for these chemicals, so an increased presence attracts more of them to the desired site.

“It's like your circulatory system is a series of highways. What makes you want to get off at New York City? We're putting an attraction in the middle of nowhere so the transplant cells will want to go there, to the target site,” said Joseph A. Frank, M.D., chief of the NIH Clinical Center Radiology and Imaging Sciences Laboratory of Diagnostic Radiology Research.