News bites: CIRM, anti-MSCs, & human eggs from stem cells

human eggs from stem cells; Saitou Lab
Human eggs from stem cells stained pink; Saitou Lab

Stem cells are always in the news so what’s up in the last week or two?

human eggs from stem cells; Saitou Lab
Human oogonia from stem cells stained pink; Saitou Lab

CIRM News

The dialogue over CIRM’s future is picking up a bit of steam. The San Francisco Chronicle did an in-depth piece on CIRM some weeks back and then opined that they didn’t feel supportive of another round of funding. I disagree. I think CIRM is a good future investment for California, but as a past CIRM grantee and stem cell advocate my opinion is probably not a surprise to readers.

Over at Science Translational Medicine, Derek Lowe expresses a pretty balanced view on the past and possible future of CIRM in a new blog post “Fighting It Out Over Stem Cells.”

MSCs = ???

It seems like MSCs are always in the news. Over at Nature, MSCs take a beating from Douglas Sipp, Pamela G. Robey and Leigh Turner. In their piece “Clear up this stem-cell mess”, they argue for abandoning the name MSC for stem cells altogether. They point out the explosion of pubs focused on MSCs (most commonly referring to “mesenchymal stem cells”) and also of clinics marketing MSCs. Another problem is that MSCs can refer to a whole bunch of different kinds of cells and probably most often to mixtures of different cells. MSC has come to be an umbrella term and is sometimes misused, which is also very problematic.

It’s probably not realistic to think that the term MSC can be fully jettisoned, but I agree it’s a messy area. Of the two main ideas for what MSC could stand for besides as a name for kinds of stem cells, I think “mesenchymal stromal cells” is way better than “medicinal signaling cells” since the latter is way too aspirational. Neither term has caught on though.

The other broader issue is that these “MSC” cells are not really mesenchymal in the strictest definition of the word which means a specific class of embryonic/fetal tissues. I guess it was originally used since MSCs are often derived from tissues that came from mesenchyme.
Maybe a better term would something like mesoderm-derived stromal cells or mesenchyme-derived stromal cells? These aren’t very catchy though. It’d mean giving up the MSC acronym, but something like “stromal precursor cells” or SPC would arguably be the best.

Stem cell eggs (oogonia) in a different basket

A team led by Mitinori Saitou has published a report in Science on the production of human eggs (oocytes) from pluripotent stem cells. This is a huge deal. The science here is very interesting as they used a xenograft system (that’s why I wrote a “different basket”) for the eggs involving mouse ovarian stromal cells. However, there are even big societal implications as the authors point out as they end their abstract this way, “These findings establish the germline competence of hPSCs and provide a critical step toward human in vitro gametogenesis.” When I think about in vitro human gametogenesis, Hank Greely’s book The End of Sex comes to mind. I also covered some possible future issues related to stem cell-produced gametes in my books Stem Cells: An Insiders Guide and GMO Sapiens too. You can see an image of the human oocytes above at the top of the post from the Saitou Lab.
What do you think was the big stem cells news of the past 1-2 weeks?

8 Comments

  1. FDA needs to stay out of this
    They are for vaccination and approve many pharmaceutical agents whose side effects are worse than the disease they treat
    They seem to focus on treatment NOT cure
    These stem cells give hope for actual cures
    Medicine doesn’t seem to look for that anymore and suppress anything that could cure
    No money in cures
    Allow adults to do their own research and choose…we don’t need parented

  2. Hi Paul! We were somewhat surprised not to see any mention in your recent news bites posts of the recent successful Phase 1 trial lead by Songtao Shi from UPenn School of Dental Medicine, involving the use of deciduous dental pulp stem cells to regenerate dental pulp in the fairly common childhood ‘dead tooth’. The results were Science Translational Medicine.

  3. I came here as it was the last MSC post and I have an MSC question.
    Is there any unequivocal evidence, i.e. proven, that MSCs injected into humans have transformed into other tissue types?

    • @Gerhard,
      Great question.
      But just to clarify, what do you mean by “other tissue types”? Do you mean fat MSCs turned into something other than fat, for instance? There have been reports of various adverse events like this, but only in some cases have they been well documented. One physician reported bone in the eye of a patient who got an injection of fat stem cells, but I never saw that published. I think it’s likely that fat stem cells injected into some patients’ eyes turned into scar tissue and led to retinal detachment. In some cases it may not be the MSCs differentiating but rather other cell types present like fibroblasts that do the damage.

      • Thanks Paul. My interest is threefold; firstly, I wanted to confirm that the dubious clinics, which offer new pancreases, lungs and brains, could not cite any evidence that MSCs (of any origin) have been shown to transform into the required tissues in humans – and certainly not in a controllable way; secondly, like you, I couldn´t find a reliable report on the “bone in the eye” story or other adverse events, although this would confirm that MSCs can differentiate in some fashion in vivo; thirdly, if there is any propensity for MSCs to form tissue in humans, why are we injecting them into patients in clinical trials, ostensibly as anti-inflammatories?

        This third aspect is close to home, as our clinic has performed several studies using MSCs for acute Graft-Versus-Host Disease after organ transplantation. I just wondered if I am unduly concerned or whether I will later read about the two or three patients that got something else with their new organ.

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