By Agnes Soos

Amid the hustle and bustle of downtown Boston, nearly four thousand researchers and exhibitors gathered for the 15th Annual ISSCR Meeting. With presentations from over thirty plenary lectures, and dozens of others featured in concurrent sessions and the daily Innovation Showcases, there definitely was no shortage of exciting research to discover and discuss. There was a record number of exhibitors this year with over 150 companies set up in Exhibit Hall. Added to this, the always-busy Meet-Up Hubs, the job boards peppered with posted offerings, and the popular Meet-the-Experts luncheons and Junior Investigator Career Panel (both with full wait-lists) offered an array of networking opportunities that definitely did not disappoint!

Though the program broadly covered stem cells in development, disease, and their applications to human health, iPSC-related work featured prominently throughout the Meeting. Central to this focus on iPSC research – and quite popular among the attendees – was the plenary talk by Shinya Yamanaka. His lecture discussed the two major medical applications of iPSCs: cell therapy and disease model/drug development. Under the cell therapy topic, he relayed the high costs associated with autologous treatments and outlined the research that has gone into identifying HLA homozygous “super” donors to overcome the prohibitive nature of allogeneic therapies. Though a first transplant was successfully performed in March of this year, this work still faces some challenges. Namely, facility-dependent handling practices appear to impact the occurrence of mutations within cancer-driving genes of the iPSC clones, necessitating further study and perhaps tighter control of how these cultures are handled. On the topic of disease modeling and drug development, Yamanaka outlined early successes in using iPSCs to gain a better understanding of Fibrodysplasia Ossificans Progressiva and the effective use of patient-derived cultures to conduct in vitro drug screening.

Organoids and organogenesis was a hot topic at this year’s Meeting with dedicated plenary and concurrent sessions offering an array of excellent talks. Juergen Knoblich’s plenary lecture presented the advantages offered by 3D organoid cultures – namely, their ability to recapitulate features of brain development and disease which cannot be easily studied using animal model systems. For example, cerebral organoids have been developed using patient-specific iPSCs to model microcephaly. Knoblich also discussed some of the advantages of introducing bioengineered matrices to manipulate organoids, demonstrating improved organoid generation with specific scaffold materials. Although organoid ‘mini-brains’ to study neural development and disease were the topic of several talks, other areas of organoid research included intestinal epithelium (‘mini guts’), pancreas, kidney, liver, and lung.

Other highlights included talks from the recipients of the McEwen Award for Innovation, Elaine Fuchs, and the Dr. Susan Lim Award for Outstanding Young Investigator, Jayaraj Rajagopal. Fuchs expertly summarized four decades of research on skin stem cells in a mere 20 minutes, covering the current understanding of stem cell activity and function in normal tissue, with aging, and in cancer, using the skin as a model system, with focus on cells within the hair follicle niche. Rajagopal lectured on the topic of airway epithelium and the interactions of three constituent cell types – a stem cell, progenitor cell, and post-mitotic differentiated cell. He presented the value of this model in studying regeneration and outlined the complexity of cellular interactions in this relatively simple cellular ensemble. Both of these talks were presented as part of the plenary session on Tissue Regeneration and Homeostasis.

Unsurprisingly, lectures in all sessions presented some very exciting science. Topics covered in the other plenary talks included: Chromatin and RNA Biology in Stem Cells, Stem Cells and Cancer, Stem Cells and Stress, Senescence, and Aging, and the Frontiers of Cell Therapy.

In addition to the above, perhaps the most memorable talk of the Meeting was the address by Sanford Greenberg on his quest to end blindness. Greenberg discussed his own experiences, relaying the struggles he faced when he become blind at 19 years of age. He outlined the goals of the Greenberg Prize, a $3 million award (in gold), which has the intent of rallying the international research community to focus efforts towards ending blindness by year 2020.

Developing effective treatments – or perhaps even cures – through clinical applications of some of the research presented at the Meeting does appear promising. This was exemplified by the work presented in the final plenary session by Masayo Takahashi on the successful use of iPSC for retinal cell therapy. However, although the results of this work are cause for excitement, Takahashi emphasized the importance of being cautious in our optimism. Though there may be progress, she is often faced with the challenge of being unable to accommodate all patients seeking treatment. Thus, she emphasized, although we must promote our successes, we should avoid placing too much emphasis on champion cases and avoid hype, so that together we may see healthy progress within the stem cell field.