Cells Weekly – October 12, 2014

by Alexey Bersenev on October 12, 2014 · 0 comments

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Cells Weekly is a digest of the most interesting news and events in stem cell research, cell therapy and regenerative medicine. Cells Weekly is posted every Sunday night!

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1. Stem Cell Person of the Year 2014
Paul Knoepfler runs annual contest Stem Cell Person of the Year. Please cast your vote!
I noticed that most nominee are keep doing a lot of good things for stem cell field persistently from year to year. So, in order to pick the best one, I propose to nominate candidates who blew your mind this particular year (2014)! This year I nominated JuuichiJigen – Japanese blogger who investigated and brought to the public problems with STAP papers. Importantly, his investigations demonstrated the role of social media and post-publication peer review in rapid self-correction of science. It was the most significant event for stem cell research and open science online this year so far. Yet another person, who “rock the boat” this year – Masayo Takahashi.

2. Long-term outcome of cell gene therapy of “bubble boy” disease
Gene therapy of inherited immunodeficiencies, such as X-linked severe combined immunodeficiency (SCID-X1) is effective method, which can provide recovery of normal immune system. However, previous trials unveiled serious adverse events – viral vector-induced leukemias in 25% of patients. The study, published this week, reports results of using new generation vector – self-inactivating γ-retrovirus:

After 12.1 to 38.7 months of follow-up, eight of the nine children were still alive. One patient died from an overwhelming adenoviral infection before reconstitution with genetically modified T cells. Of the remaining eight patients, seven had recovery of peripheral-blood T cells that were functional and led to resolution of infections.

Good results so far! patients will be monitored for 15 years. From press release:

“Our goal was to take the molecular data from the prior trial and use it to produce a vector that would remain effective and at the same time reduce the risk of leukemia,” said David A. Williams,

“The efficacy data from our study is clear: The vector does work to correct the disease. And by a surrogate endpoint, we have improved the treatment’s safety, although it’s too early to say that we’ve completely eliminated the long-term risk of leukemia.”

Also read: SCID-X1 Gene Therapy, Take 2 – DNA Science Blog by Ricki Lewis

3. Australian “stem cell therapeutic” company under fire
Sydney-based Regeneus recently made headlines with news about “approval by AFL” of use their commercial product HiQCell in athletes. Australian media outlet ABC reported this week that “company is under fire” for giving misleading information about their products and trials:

7.30 has also learned the AFL was displeased when Regeneus put out the press release because it felt was dressed up to look like an official AFL endorsement.
In fact, it was based on one discussion with the AFL chief medical officer about one player from one club.

However, the complaint letter obtained by 7.30 points out the statement left out some key information.
“It is misleading because the control (placebo) group in that trial also achieved the same reduction in pain and slowing of cartilage degeneration,” the letter said.

You can read company’s reply here.

4. Isolation of mesenchymal stromal cells by biophysical characteristics
A group of researchers identified biophysical characteristics of MSC, which could be used to isolate these cells via microfluidic device. From press release:

After measuring several other physical traits, the researchers found two that could be combined with size to completely distinguish MSCs from other stem cells: stiffness of the cell, and the degree of fluctuation in the cell’s nuclear membrane.
“You don’t need more than these three, but you also can’t use fewer than these three,” Van Vliet says. “We now have a triplet of characteristics that identifies populations of cells that are going to be multipotent versus populations of cells that are only going to be able to become bone or cartilage cells.”

Looks like great investment opportunity!

5. Risk of feeder-derived tumorigenesis in human iPS cell culture
Japanese researchers investigated potential risk of tumorigenesis, related to xenogenic feeder cells, routinely used for culture of human iPS cells:

We examined the genetic origin and characteristics of tumors, that were formed when 13 hiPSC lines, established by ourselves, and 201B7 hiPSC from Kyoto University were transplanted into severe combined immune-deficient (SCID) mice. Though teratomas formed in 58% of mice, five angiosarcomas, one malignant solitary fibrous tumor and one undifferentiated pleomorphic sarcoma formed in the remaining mice.
… hiPSCs grown on MMC-SNL feeder cells have a high risk of generating feeder-derived malignant tumors. The possible mechanism(s) of growth restoration and the formation of multiple tumor types are discussed with respect of the interactions between MMC-SNL and hiPSC.

What else should be said against using xeno-feeder for human pluripotent stem cell culture?

6. Exchange of membrane components between MSC and cardiac cells
Interesting phenomenon, related to MSC biology was recently described. In experimental model in vitro, MSC and cardiac cells actively exchanged membrane components:

This study clearly demonstrates for the first time that MSC and HL-1 cells exchange membrane components in a time-dependent manner when cocultured. We found that 100% of the MSC gained membrane from the HL-1 cells after 20 hours while 48% of the HL-1 cells gained membrane from the MSC.

This phenomenon can explain potential mechanism of action of MSC in cardiac diseases and “transdifferentiation magic”.

7. Using organotypic units for tissue engineering
A group of researchers used freshly isolated or cultured “esophageal organoid units” to engineer esophagus in vivo on simple degradable scaffold:

None have generated human TEE with mesenchymal components. We hypothesized that sufficient progenitor cells might only require basic support for successful generation of murine and human TEE.
Tissue-engineered esophagus forms after transplantation of mouse and human organ-specific stem/progenitor cells in vivo on a relatively simple biodegradable scaffold.

8. All about cell fate
EuroStemCell posted a great summary on cell fate decision and reprogramming. Also watch produced by EuroStemCell and freshly released documentary Cell Fate: Journeys to specialisation.

9. Stem cell culture advances
The Cell Culture Dish blog posted an overview of new stem cell culture tools, presented on ISSCR 2014 conference.

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