Epigenetic Changes in Cancer

Lung cancer close-up MOREDUN ANIMAL HEALTH LTD/SPL / Gettyimages

The study of how covalent marks on DNA and histones are involved in the origin and spread of cancer cells
is also leading to new therapeutic strategies.

Much of the current hype in epigenetics stems from the recognition of its role in human cancer. Yet, intriguingly, the first epigenetic change in human tumors—global genomic DNA hypomethylation—was reported way back in the early 1980s, at about the same time the first genetic mutation in an oncogene was discovered.1 So why the delay in recognizing the importance of epigenetics in cancer?

In the 1980s epigenetics was a fledgling discipline, hampered by methodological limitations, while genetic knowledge of Continue reading

The Skin Gun

Scientists have invented a ballistic new way to treat burns and skin abrasions – shoot them with a stem cell gun. The gun – a sterile syringe that loads into a spraying nozzle – releases a patient’s own stem cells, generated from a piece of healthy skin, which can immediately begin repairing the skin.

 

Largest animal genome discovered

Wikimedia commons, Paul Hebert

Scientists have sequenced the entire genome of Daphnia pulex, a small crustacean commonly used as a model organism for basic biological function studies, and revealed the largest number of genes of any animal genome. The paper, published last week in Science, reports that Daphnia has a total of 30,907 genes, significantly more than the 23,000 estimated human genes.

Pfizer cuts R&D

Pfizer announce last week that it will cut some 20 percent of its R&D expenditure, from $8.5 million to $7 million, sometime next year. The pharmaceutical company also plans to shut down a UK research facility that currently employs 2,400 people and to drastically reduce staff in its Connecticut research center, according to ScienceInsider, although it may increase its Massachusetts workforce by several hundred.

While the news has come as a surprise to many, GlaxoSmithKlein’s chief executive Andrew Witty indicated that Pfizer’s loss may be GSK’s gain. “We absolutely will look at… high calibre people, talented people there,” Witty told The Telegraph. “There may be some people who want to come here…and of course we’ll look at that.”

90 retractions coming?

Nearly 100 papers might be pulled from the literature because they didn’t receive proper institutional approval, according to Retraction Watch. Joachim Boldt, former head of anesthesia at the Klinikum Ludwigshafen in Germany, was fired last year after suspicions were raised about one 2009 Anesthesia & Analgesia paper that appeared to be based on research that hadn’t taken place. But last week an ongoing investigation by Klinikum Ludwigshafen and the German state medical association of Rheinland Pfalz announced that as many as 90 studies failed to get proper institutional approval — grounds for the immediate retraction of an article, according to a letter from the editors of 11 journals. (Hat tip to ScienceInsider)

News in a nutshell

Vaccines prevent cancer?

Some vaccinations routinely given to children, such as those for hepatitis B and polio, may lower the risk of certain cancers, like leukemia. Comparing 2,800 cases of childhood cancer in Texas to more than 10,000 healthy individuals, researchers found that children born in counties where the hep B vaccine was common were 20 percent less likely to develop cancer. Similarly, kids born in areas where children are typically vaccinated for both the polio and hep B were 30 to 40 percent less likely to contract the disease, according to a new study published last week in the Journal of Pediatrics. Though some parents choose against vaccinating their children because they believe the shots can cause autism, “people can take a step back and really look at the benefit that vaccines provide — not just for the infectious diseases they were intended to prevent,” study author Michael Scheurer of Baylor College of Medicine in Texas, told Reuters. (Hat tip to FierceVaccines)

Flickr, Blake Patterson

Q&A: Alzheimer’s trial disconnect

While preclinical studies identify ways to prevent Alzheimer’s disease in animals, human trials test these same therapies in symptomatic patients — long after they are most likely to be effective

Alzheimer’s disease (AD) is a growing threat that currently afflicts some 35 million people worldwide. Without the advent of preventive therapies, the neurodegenerative disease will strike as many as 100 million people by 2050. And while laboratory studies in animal models of AD continue to uncover promising avenues for disease prevention, clinical trials in humans target patients who are already showing signs of neural degeneration.

Image: Wikimedia commons, Alzheimer Forschung Initiative e.V.

Disease biologist Todd Golde of University of Florida College of Medicine talked to The Scientist about this disconnect, its consequences, and possible solutions to the problem — the topic of an opinion piece he co-authored, published online today (January 26) in Neuron.
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Mom’s blood carries fetus genome

A complete copy of the fetal genome exists in the mother’s blood, suggesting many prenatal diagnoses could be performed noninvasively

[Published 8th December 2010 07:00 PM GMT]

Circulating in the blood of pregnant women is the full genome of their unborn child, according to a study published online today (December 8) in Science Translational Medicine.

Image: Wikimedia commons, Swangerschaft

The results suggest that whole genome sequencing of fetuses may be possible without invasive procedures, and hold implications for the prenatal diagnoses of every genetic disease.

This study provides “a window into the fetal genome,” said reproductive geneticist Diana W. Bianchi of the Mother Infant Research Institute at the Tufts University School of Medicine, who was not involved in the research. “In principle, that means that you could noninvasively prenatally diagnose anything because the sequence is going to be there.”

In 1997, chemical pathologist Dennis Lo of The Chinese University of Hong Kong and his colleagues discovered the presence of fetal DNA in maternal blood. Scientists have since developed noninvasive procedures to prenatally diagnose certain diseases. Down syndrome, for example, results from an abnormal number of chromosomes, and can be detected by searching mother’s blood for disproportionate amounts of DNA from different chromosomes. And genetic diseases inherited from the father may also be detected by searching the mother’s blood for the paternal mutation.

It was unclear, however, if the entire fetal genome was present in the maternal plasma, which would give clinicians more confidence in the tests currently available by limiting the rate of false-negative results. Additionally, it might make it possible to screen for genetic diseases that are caused by genetic mutations inherited from the mother, as well as sequence the entire genome of the unborn child, without subjecting the mother to invasive procedures that carry a small risk of miscarriage.

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