Embryonic Stem Cell Therapy Causes Cancer in Teenage Boy

From Discover Blogs, 80 beats

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new study shows that teenage boy developed cancerous tumors because of the stem cell therapy he received years ago for a rare genetic condition. The boy, now 17, suffered from ataxia telangiectasia, or AT, a neurodegenerative disease that interferes with the part of the brain that controls movement and speech. AT patients do not usually live past their teens or 20s, and the Israeli boy, whose identity was not publicly revealed, was taken to Russia for experimental treatment. The first neural stem cells, taken from fetuses, were first injected into his brain and spinal cord when he was nine, and he received further injections at ages 10 and 12.
His condition deteriorated and he was using a wheelchair by age 13, when he also began to complain of headaches. Tests showed two growths, one pushing on his brain stem and the other on his spinal cord. The tumors were removed in 2006 and his health has since remained stable. But scientists at Tel Aviv University who wanted to determine the origin of the cancer have been in the lab ever since, and their findings have just been published in PLoS Medicine. The team found that the tumor could not have arisen from the boy, because he [has two disease-causing versions of the gene] that causes AT, while the DNA from the tumor cells carried only the normal version [The Scientist].The tumor studied was the one removed from the spinal cord; they could not test the growth that appeared in the brain, but believe it was also caused by the injected tissue. Donor-derived cells might have been able to spark tumours in this patient because people with ataxia telangiectasia often have a weakened immune system, say the researchers. It is not clear whether the stem cell therapy helped his genetic condition [BBC].
The case raises a number of ethical questions. For all the promise, researchers have long warned that they must learn to control newly injected stem cells so they don’t grow where they shouldn’t, and small studies in people are only just beginning [AP]. And, because the patient’s immune system was impaired, it’s not yet clear whether the increased risk of cancer is specific to patients with suppressed immune systems, something particular to the procedure done in Moscow, or a danger with neural stem cell transplantation in general, said Uri Tabori, a pediatric hematologist and oncologist…. “It’s a cautionary tale for studies currently being done in the US and elsewhere,” said [Arnold] Kriegstein [The Scientist], a U.S. stem cell researcher.

A piece of History – Watson and Crick’s paper on DNA

Watson, J.D. and Crick, F.H.D 1953 Molecular Structure of Nucleic Acids: A Struture for Deoxyribose Nucleic Acid Nature Vol: 171 737-738

PCR song

From a bunch of scientists…

The PCR Song

There was a time when to amplify DNA,
You had to grow tons and tons of tiny cells.

Then along came a guy named Dr. Kary Mullis,
Said you can amplify in vitro just as well.

Just mix your template with a buffer and some primers,
Nucleotides and polymerases, too.

Denaturing, annealing, and extending.
Well it’s amazing what heating and cooling and heating will do.

PCR, when you need to detect mutations.
PCR, when you need to recombine.
PCR, when you need to find out who the daddy is.
PCR, when you need to solve a crime.

(repeat chorus)

Menstrual cycle animations

Good resource on the Menstrual cycle.

From msnbc

From PBS

Clarifying cloning

This is a good summary from Genetics Policy Center on how cloning is achieved and its uses.

A lyrical view of life

View this amazing presentation with a nice cup of coffee and a cosy chair. Sit back and let life unfold before you.

Frans Lanting’s Lyrical View of Life

Height Gene Discovered – HMGA2

Scientists discover HMGA2. Gives one a good 1 cm more for homozygotes.

Scientists discover height gene

People who carry two copies of the “tall” version of the HMGA2 gene are up to 1cm taller than those who carry two copies of the “short” version.

The international team of researchers say the discovery could aid a greater understanding of the link between height and disease.

They predict in the journal Nature Genetics many other genes will now be uncovered that control height.

Although it has long been clear that genetics plays a key role in determining a person’s height, the genes involved have remained a mystery.

The latest study is a collaboration between Harvard University, the Children’s Hospital Boston, Oxford University and the Peninsula Medical School in Exeter.

They analysed the genomes of 5,000 white European patients, who gave DNA samples and details of their height and weight for medical studies into diabetes and heart disease.

They found just one tiny change in the HMGA2 gene had an impact on a person’s height.

The finding was confirmed by searching for the same two key versions of the gene in a further 30,000 patients.

Cancer link

Around 25% of white Europeans carry two copies of the “tall” version of the gene, while a similar proportion have two copies of the “short” version.

Carrying one copy of the “tall” version of the gene adds around 0.5cm to a person’s height, while two copies adds nearly a full centimetre.

Previous research has suggested that HMGA2 plays an important role in human growth.

Rare, severe mutations in the gene cause dramatic alterations of body size in mice and humans.

Researcher Dr Tim Frayling, of the Peninsula Medical School, said: “Height is a typical ‘polygenic’ trait, in other words many genes contribute towards making us taller or shorter.

“Clearly, our results do not explain why one person will be 6ft 5in (192 cms) and another only 4ft 10in (145cms).

“This is just the first of many that will be found, possibly as many as several hundred.”

A greater understanding of the genes behind height could also provide clues about risk of disease.

Taller people are statistically more likely to be at risk from prostate, bladder and lung cancer.

This suggests that the genes that regulate cell growth and division may also play a role in the uncontrolled cell proliferation characteristic of cancer.

Conversely, shorter people are known to have a higher risk of heart disease.

Professor Joel Hirschhorn, an expert in genetics at Harvard, said “This is the first convincing result that explains how DNA can affect normal variation in human height.

“Because height is a complex trait, involving a variety of genetic and non-genetic factors, it can teach us valuable lessons about the genetic framework of other complex traits, such as diabetes, cancer and other common human diseases.”

He added: “By defining the genes that normally affect stature, we might someday be able to better reassure parents that their child’s height is within the range predicted by their genes, rather than a consequence of disease.”

Five “Designer Babies” Created for Stem Cells

Five healthy babies have been born to provide stem cells for siblings with serious non-heritable conditions.

Read the article from New Scientist. Five “designer babies” created for stem cells

Phenylthiocarbamide – Stephen Wooding

A summary of the research done on this famous allele. Includes basis for selection of this trait both in humans and other apes.

Wooding S. 2006 Phenylthiocarbamide: A 75-Year Adventure in Genetics and Natural Selection. Genetics.172(4): 2015–2023.

restriction enzymes and gel electrophoresis

A good online tutorial on restriction enzymes and gel electrophoresis.

By Prentice Hall.

Molecular Biology Lab Bench Activity by ThereaKnapp Holtzclaw.