Limited access to human embryonic stem cell lines? Survey says...

Geoff Lomax is CIRM's Senior Officer to the Standards Working Group 

Is the ability to obtain embryonic stem cell lines hindering research, what factors influence access, and does availability vary by state? These questions have been the subject research and their answers are not entirely clear. A recent publication in Nature by Aaron Levine of the Georgia Institute of Technology suggests that access issues do impact research. In his paper, he writes:

“an inability to acquire certain hESC lines have likely hindered hESC science in the United States.”

This conclusion is based on a survey of stem cell scientists in the United States. Levine focused his discussion on the subset who reported using human embryonic stem cells. A sizable number of these scientists--38%--reported excessive delay in obtaining lines and 28% reported they were unable to acquire a stem cell line they wanted to study. Factors attributed to delays included problems with materials transfer agreements (MTAs) and an inability to obtain approval from an institutional oversight committee. Based on these findings, Levine writes:

“These results suggest scientists in the United States cannot conduct comparative studies with a diverse set of hESC lines and suggest that access issues have contributed to this situation.”

I found these results intriguing because in a recent study quantifying the use of hESC lines by CIRM researchers, my colleagues and I found that scientists had obtained a diverse array of embryonic cell lines – 138 unique lines including 17 newly derived hESC lines. I suspected the apparent discrepancy in findings may be related to the research environment in California and other states with policies designed to support access to and creation of human embryonic stem cell lines. The answer to the question of whether availability varies by state is not clear because Levine’s responses are not geography correlated.

Our findings suggest widespread access in California, but it is important to keep in mind we examined what lines researchers ultimately accessed, not what they were unable to obtain. To gain further insight, I did a quick survey of my Science Office colleagues. Many hadn’t heard of cases where access to cell lines had been a deterrent to research for our grantees. I also queried grantees who were carrying out comparative studies. Jeanne Loring of the Scripps Research Institute has a CIRM grant to compare cell lines. When I emailed her she said:

“We've had no trouble getting hESC lines from collaborators all over the world. There are hundreds of cell lines available, and most are of good quality.”

Another colleague did recall instances where there were delays in obtaining cell lines, so I emailed Steve Peckman, who is Associate Director of the UCLA Broad Stem Cell Research Center. He did offer specific examples where material transfer agreements were a source of delay. In addition, Peckman indicated the NIH restrictions on the use of certain popular lines, such as HUES 9, did impact approval by institutional oversight committees even in cases where no NIH funding was involved, so perhaps California researchers were not immune to access issues.

Peckman also said that a game changer at UCLA was the ability to study newly derived UCLA 1-6 hESC lines created with CIRM funding (here is a list of all cell lines considered "acceptably derived" by CIRM). He suggested new cell line derivation has been a tremendous benefit for researchers, potentially attenuating problems encountered elsewhere. He noted, however, that UCLA and others are not well equipped to distribute lines outside their home institution, which could explain Levine’s findings that certain individual researchers were having a hard time accessing lines. Peckman’s solution was to support the development of a banking and distribution network with uniform material transfer agreements.

Peckman’s observations are reassuring in light of the decision by CIRM’s board to move forward with CIRM’s Human Pluripotent Stem Cell Initiative. The initiative includes a “Bank Award”. The concept proposal for this award says:

“California researchers have already generated many disease‐specific human induced pluripotent stem cell (hiPSC) and human embryonic stem cell (hESC) lines, many with CIRM funds… CIRM intends to provide funds for the establishment of an hPSC repository located in California that will bank and distribute high quality, disease specific hiPSC and hESC lines generated in California for research use.”

The comparative ease of access in California, as evidenced by Loring’s work, may be attributed to our comprehensive scientific, regulatory and facilities programs designed to facilitate research. CIRM’s programmatic efforts are consistent with Levine’s suggestion that “funding agencies … encourage research using multiple diverse hESC lines.”

We are always interested in hearing more. If you have experience accessing and utilizing hESC lines, we encourage you to comment below or contact me glomax@cirm.ca.gov.

G.L.