26 Feb 2014 04:03

Scientist: Let's not discredit acid-bath stem cell studies--yet


The news has swept the Internet that a potential stem cell breakthrough unveiled in January by a major Japanese research institution is now under investigation.

The allegations of irregularities in the research come less than a month after two high-profile papers were published in the journal Nature. The papers detailed a new method of creating embryonic-like stem cells by essentially shocking adult mouse stem cells with an acid bath. The work stunned stem cell researchers. The process seemed astoundingly simple--almost too simple.

On Feb. 14, the RIKEN Center for Developmental Biology in Kobe, Japan, said it was looking into claims made on several blogs purporting failed attempts to replicate the studies' results. The institution said it is also looking into allegations that biologist Haruko Obokata, the lead author of the two papers and a RIKEN employee, used duplicated images from different experiments in the studies. Nature is also conducting its own investigation.

Some say the allegations represent a larger problem of irreproducibility in early science research. But others, like Edward Ahn, managing director and chief science officer of Cambridge, MA-based MedCap Advisors, think we shouldn't jump to conclusions quite yet.

"I think it's par for the course of this sort of protocol," Ahn tells FierceBiotech Research.

He says it's common for some things to get left out of the methodology when a new paper is published, and it will likely take more time for other labs to figure out how to reproduce Obokata's work.

"Of course, we should consider the fact that it's a competitive field that these people are in. The researchers that developed this have a lot to gain. But given the nature of this work, people may cry foul a bit too early," says Ahn.

Ahn is a senior lecturer at Harvard University's School of Engineering and Applied Science and vice chairman of the MIT Enterprise Forum of Cambridge. He says if the acid-wash method can be reproduced, Obokata's work could have a huge impact on stem cell research.

First engineered by Shinya Yamanaka at Kyoto University in Japan in 2006, the original cell reprogramming method uses viruses to introduce the new DNA information into adult cells. One of the major drawbacks of using induced pluripotent stem (iPS) cells in therapies is that these viruses could conceivably introduce foreign DNA into the cells, prompting tumor growth instead of helping to grow healthy tissue.

Obokata and co-authors from Brigham and Women's Hospital and Harvard University detail a new way of creating embryonic-like stem cells by stressing adult cells close to death by exposing them to trauma, low oxygen levels and an acidic environment. A few days after exposure to these different stresses, the cells had not only survived but reverted back into a state equivalent to that of an embryonic stem cell. These cells were then able to redifferentiate into any type of cell, depending on the environment into which they were placed. The researchers tried the method again in blood cells in mice and found comparable results.

Not only does the method eliminate many of the concerns associated with embryonic and iPS cells, but Ahn says it also means that embryonic-like stem cells could be generated more quickly at a much higher yield than iPS cells, production of which is largely inefficient due to low cell-conversion rates.

"I think this new method of obtaining stem cells could result in a renaissance in stem cell research," Ahn says.

Ahn says further research on this method will have to address how long these acid-washed stem cells behave like stem cells and whether they have a finite life.

For now, Ahn is remaining hopeful that Obokata's method can be imitated and eventually used for disease modeling and, later down the road, experimental stem cell therapies.

"But if this protocol is that finicky and not that robust in its ability to translate into something more impactful for society, then you may as well stick with iPSC method," Ahn says. -- Emily Mullin (email | Twitter)

For more: Exposure to acid turns adult cells into stem cells