Stem Cell Roundup: hESCs turn 20, tracking cancer stem cells, new ALS gene ID’d

Stem Cell Image of the Week

Picture1This week’s stunning stem cell image is brought to you by researchers in the Brivanlou Lab at Rockefeller University. What looks like the center of a sunflower is actual a ball of neural rosettes derived from human embryonic stem cells (ESCs). Neural rosettes are structures that contain neural stem and progenitor cells that can further specialize into mature brain cells like the stringy, blue-colored neurons in this photo.

This photo was part of a Nature News Feature highlighting how 20 years ago, human ESCs sparked a revolution in research that’s led to the development of ESC-based therapies that are now entering the clinic. It’s a great read, especially for those of you who aren’t familiar with the history of ESC research.

Increase in cancer stem cells tracked during one patient’s treatment
Cancer stem cells are nasty little things. They have the ability to evade surgery, chemotherapy and radiation and cause a cancer to return and spread through the body. Now a new study says they are also clever little things, learning how to mutate and evolve to be even better at evading treatment.

Researchers at the Colorado Cancer Center did three biopsies of tumors taken from a patient who underwent three surgeries for salivary gland cancer. They found that the number of cancer stem cells increased with each surgery. For example, in the first surgery the tumor contained 0.2 percent cancer stem cells. By the third surgery the number of cancer stem cells had risen to 4.5 percent.

Even scarier, the tumor in the third surgery had 50 percent more cancer-driving mutations meaning it was better able to resist attempts to kill it.

In a news release, Dr. Daniel Bowles, the lead investigator, said the tumor seemed to learn and become ever more aggressive:

Bowles headshot

Daniel Bowles

“People talk about molecular evolution of cancer and we were able to show it in this patient. With these three samples, we could see across time how the tumor developed resistance to treatment.”

 

The study is published in the journal Clinical Cancer Research.

New gene associated with ALS identified.
This week, researchers at UMass Medical School and the National Institute on Aging reported the identification of a new gene implicated in the development of amyotrophic lateral sclerosis (ALS). Also known as Lou Gehrig’s disease, ALS is a horrific neurodegenerative disorder that degrades the connection between nerve signals and the muscles. Sufferers are robbed of their ability to move and, ultimately, even to breathe. Life expectancy is just 3 to 5 years after diagnosis.

To identify the gene, called KIF5A, the team carried out the largest genetics effort in ALS research with support from the ALS Association, creators of the Ice Bucket Challenge that raised a $115 million for research. The study compared the genomes between a group of nearly 22,000 people with ALS versus a group of over 80,000 healthy controls. Two independent genetic analyses identified differences in the expression of the KIF5A gene between the two groups.

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Cartoon representing the role that KIF5A plays in neurons. (Image: UMass Medical School)

KIF5A is active in neurons where it plays a key role in transporting cell components across the cell’s axon, the long, narrow portion of the cell that allows neurons to send long-range signals to other cells. It carries out this transport by tethering cell components on the axon’s cytoskeleton, a structural protein matrix within the cells. Several mutations in KIF5A were found in the ALS group which corroborates previous studies showing that mutations in other cytoskeleton genes are associated with ALS.

One next step for the researchers is to further examine the KIF5A mutations using patient-derived induced pluripotent stem cells.

The study was published in Neuron and picked up by Eureka Alert!

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