August 1, 2007

Embyonic Stem Cell Reseach, Cloning, and the L.A. Times

Jared Bridges at FRC writes that when he read Los Angeles Times staff reporter Stephanie Simon's report this morning on the continuing fight in the states against embryonic stem cell research (even in states which have passed initiatives to support such research), his jaw nearly dropped when he read these lines:

Embryonic stem cell research typically begins with cloning. Scientists insert the genetic material from an adult human cell into a human egg that's been emptied of its own DNA. The cloned cell is then nurtured in the lab for several days, until it grows into a blastocyst, a microscopic clump of cells that could theoretically develop into a fetus if attached to a uterine wall.

As he reread the article, he noticed this rather peculiar correction ...

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July 6, 2007

Researchers Turn Stem Cells Taken From Fat Tissue Into 'Suicide genes' That Seek Out And Destroy Tumors

cel1.jpgScientists have developed a new gene therapy by using 'suicide genes' derived from mesenchymal stem cells, which search out and kill cancerous tumours.

Mesenchymal stem cells are a well-characterized population of adult stem cells, found in the bone marrow, which can form a variety of cell in the laboratory, including fat cells, cartilage, bone, tendon and ligaments, muscles cells, skin cells and even nerve cells. Mesenchymal stem cells have been studied in great detail and scientists have advanced knowledge about how to grow these cells in culture. Unlike most other human adult stem cells, mesenchymal stem cells can be obtained in quantities appropriate for clinical applications. In the study reported on here, the researchers used fat tissue as the source for mesenchymal stem cell - derived "suicide genes" to attack metastatic tumor cells, a novel way to attack small tumor metastases that evade current detection techniques and treatments:

... "These fat-derived stem cells could be exploited for personalized cell-based therapeutics," said the study's lead investigator, ...

... Mesenchymal stem cells help repair damaged tissue and organs by renewing injured cells. They are also found in the mass of normal cells that mix with cancer cells to make up a solid tumor. Researchers believe mesenchymal stem cells "see" a tumor as a damaged organ and migrate to it, and so might be utilized as a "vehicle" for treatment that can find both primary tumors and small metastases. These stem cells also have some plasticity, which means they can be converted by the micro environment of a given tissue into specialized cells ...

... After extracting the stem cells from human fat tissue the researchers worked to find a less toxic way to treat colon cancer than the standard-of-care chemotherapy agent, 5-fluorouracil (5-FU), which can produce toxic side effects in normal cells. They expanded the number of mesenchymal stem cells in the laboratory and then used a retrovirus vector to insert the gene cytosine deaminase into the cell. This gene can convert a less toxic drug, 5-fluorocytosine (5-FC), to 5-FU inside the stem cells, and the chemotherapy can then seep out into the tumor, producing a lethal by-stander effect.

In nude mice -- animals with an inhibited immune system -- engrafted with human colon cancer, the researchers first injected the engineered mesenchymal stem cells, then 5-FC. They found tumor growth was inhibited by up to 68.5 percent in the animals, and none of the mice exhibited any signs of toxic side effects.

However, none of the animals remained tumor-free. "The procedure was quite effective even though we applied the stem cells just once. Obviously, repeated treatment will increase the efficacy, as would using this strategy in combination with other treatments," Altaner said.

Continue reading ...

Related readings:
Adult Stem Cells
Mesenchymal Stem Cells: Isolation and Therapeutics
Stem Cells, Fat Tissue as Routes to Cell-Based Therapy
Stem Cell Review

Posted 9:45 PM | TrackBack (0)

July 2, 2007

Study Raises Troubling Questions About Stem Cell Trial Design

Bone%20marrow%20stem%20cells.jpgImage: Bone marrow stem cells: More work is needed to understand how the cells behave in the body.

Professor Harald Arnesen and colleagues from the Ullev?University Hospital, Oslo, Norway looked at studies published to date on the relatively new technique of using of autologous (derived or transferred from the same individual's body) stem cells derived from bone marrow cells to strengthen cardiac function. The authors refer to a trial done in 2002 in which the cells were administered into the heart with encouraging results. After reviewing the studies,
Professor Arnesen has called for a moratorium on the use of the stem cells to prevent heart attacks because he believes the design of the study that resulted in some apparently successful trials is flawed. Apparently, the outcome of the study that resulted in a conclusion that the treatment group showed improvement when compared with the control group could be explained by the control group doing particularly badly, with a six percent mortality:

"It is astonishing that it is driven by a very poor outcome in a placebo group. In the present setting this figure is unusually high, as is the incidence of reinfarctions also of 6 per cent reported in the placebo group in the Frankfurt study."

The team approached the company that made the substance that was injected into the heart as a control, instead of the stem cells. Prof Arnesen said: "We were really astonished to learn from the producer in Maryland, US, that this medium was never intended or accepted for use in humans at all."

"We are warning doctors about the dangers of introducing these protocols to thousands of new patients in large studies," he said. "We need more research."

Continue reading: Stem cell trial warning

Related:
Injecting Autologous Cells Could Relieve Urinary Incontinence
Clinical Trial Suggests Bone Marrow Stem Cells Are Useful for Spinal Cord Injury; PrimeCell Therapeutics Provided Pre-Clinical Study

Posted 10:41 PM | TrackBack (0)

June 30, 2007

Another Adult Stem Cell Success

U.S. researchers are developing a process that would allow a patient's own stem cells to be used for the development and production of new skin tissue.

Columbia University Medical Center said the tissue could be used for facial reconstruction following disfiguring injuries from war, cancer surgery or accidents.

more

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May 26, 2007

Adult Stem Cells Used to Produce Insulin

Researchers at the University of Texas Medical Branch at Galveston report a fundamental discovery that may someday help cure Type 1 Diabetes. The medical technology, based upon novel adult stem cell research, enables people to grown their own insulin-producing cells, which could be used to repair the diseased pancreas.

The findings were announced in the June 2007 medical journal Cell Proliferation in a paper titled "the first demonstration that human umbilical cord blood-derived stem cells can be engineered" to synthesize insulin.

Here's the amazing thing: for years we've been told by embryonic stem cell proponents that cures for diabetes are being prevented because the government does not fund their embryo destroying research. However, during this same perioed of time scientists have been developing potential cures, with tangible results, that actually bay do what ESC proponents dream.

Here's their press statement:

In a fundamental discovery that someday may help cure type 1 diabetes by allowing people to grow their own insulin-producing cells for a damaged or defective pancreas, medical researchers here have reported that they have engineered adult stem cells derived from human umbilical cord blood to produce insulin.

The researchers announced their laboratory finding, which caps nearly four years of research, in the June 2007 issue of the medical journal Cell Proliferation, posted online this week. Their paper calls it "the first demonstration that human umbilical cord blood-derived stem cells can be engineered" to synthesize insulin

"This discovery tells us that we have the potential to produce insulin from adult stem cells to help people with diabetes," said Dr. Randall J. Urban, senior author of the paper, professor and chair of internal medicine at the University of Texas Medical Branch at Galveston and director of UTMB's Nelda C. and Lutcher H. J. Stark Diabetes Center. Stressing that the reported discovery is extremely basic research, Urban cautioned: "It doesn't prove that we're going to be able to do this in people -- it's just the first step up the rung of the ladder."

The lead author of the paper, UTMB professor of internal medicine/endocrinology Larry Denner, said that by working with adult stem cells rather than embryonic stem cells, doctors practicing so-called regenerative medicine eventually might be able to extract stem cells from an individual's blood, then grow them in the laboratory to large numbers and tweak them so that they are directed to create a needed organ. In this way, he said, physicians might avoid the usual pitfall involved in transplanting cells or organs from other people -- organ rejection, which requires organ recipients to take immune-suppressing drugs for the rest of their lives.

Huge numbers of stem cells are thought to be required to create new organs. Researchers might remove thousands of donor cells from an individual and grow them in the laboratory into billions of cells, Denner explained. Then, for a person with type 1 diabetes, researchers might engineer these cells to become islets of Langerhans, the cellular masses that produce the hormone insulin, which allows the body to utilize sugar, synthesize proteins and store neutral fats, or lipids. "But we're a long way from that," Denner warned.

Denner said this research, which reflects a fruitful collaboration with co-authors Drs. Colin McGuckin and Nico Forraz at the University of Newcastle Upon Tyne in the United Kingdom, used human umbilical cord blood because it is an especially rich source of fresh adult stem cells and is easily available from donors undergoing Caesarian section deliveries in UTMB hospitals. "However," he added, "embryonic stem cell research was absolutely necessary to teach us how to do this."

Embryonic stem cells have been engineered to produce cardiac, neural, blood, lung and liver progenitor cells that perform many of the functions needed to help replace cells and tissues injured by many diseases, the paper notes. Among the insights into cell and tissue engineering gained from work with embryonic stem cells, it adds, are those "relevant to the engineering of functional equivalents of pancreatic, islet-like, glucose-responsive, insulin-producing cells to treat diabetes."

The researchers said they tested adult stem cells in the laboratory to ensure that they were predisposed to divide. Then they used a previously successful method in which complex signals produced by the embryonic mouse pancreas were used to direct adult stem cells to begin developing, or "differentiating," into islet-like cells.

As they grew these adult stem cells in the laboratory, the researchers conducted other tests in which the cells to be engineered showed evidence of a characteristic, or marker, known as SSEA-4 that was previously thought to exist only in embryonic cells. They also found that, just as embryonic cells have been shown to do, these adult stem cells produced both C-peptide, a part of the insulin precursor protein, and insulin itself. Confirming the presence of the C-peptide was especially crucial, the researchers suggested, because although insulin is often found in the growth media with which the cells are nurtured and is often taken up by such cells, the presence of the C-peptide proves that at least some of the insulin was produced, or synthesized, by the engineered cells.


Posted 10:34 AM

May 19, 2007

Stem Cell Treatment for Baldness

No, the treatment has not been developed for humans but studies show concrete results in animals:

IT could be the answer to the prayers of millions of bald men. Scientists have coaxed stem cells into growing hair for the first time.

Within a decade, advances in stem-cell science could help them to regrow their own hair where it has been lost.

The breakthrough could also lead to new treatments for other conditions, such as alopecia, in which hair is lost in patches.

Writing in the journal Nature, American scientists described how they had shown that adult mammals were able to grow new hair follicles.

It had been thought that follicles, the tiny structures responsible for hair growth, were always formed before birth, with their gradual death leading to baldness.


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March 7, 2006

South Korean scientist admits faking research

This is really big news:

Disgraced South Korean cloning expert Hwang Woo-Suk has for the first time admitted playing a key role in fabricating stem cell research, Yonhap news agency has said.

Hwang, under questioning for a fifth day by prosecutors, admitted telling a researcher working for him to fake key research that won him international acclaim in 2005, the agency said.

"Hwang was admitting that he directed Kwon Dae-kee, a senior researcher at his laboratory, to manipulate samples for DNA testing of stem cell lines numbers 4-11 in connection with Hwang's 2005 paper," the agency quoted an unidentified prosecution official as saying.

Prosecutors declined to comment on the report.

Hwang, 52, claimed in the landmark paper last year that he had created 11 patient-specific stem cells through cloning. But a panel of experts concluded last month that the claims were bogus.

The panel at Seoul National University also concluded that a 2004 paper by Hwang, in which he claimed to have produced a stem cell from a cloned human embryo, was also fabricated.

According to prosecutors, Hwang still insists that the data for the 2004 paper is genuine.

Prosecutors called Hwang for questioning on Thursday concerning his alleged misuse of millions of dollars in funds. They say the professor made donations to politicians and failed to account for 6.2 billion won (6.4 million dollars) in research funding.

Stem cells are master cells that have the potential to develop into any organ of the body. Scientists believe they could be used to fight a range of illnesses including cancer, diabetes and Alzheimer's disease.

Source: Channel News

Posted 1:12 PM | TrackBack (0)

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