Overview of Yamanaka Talk at #ISSCR2015 by Heather Main

Heather_MainISSCR day one

By Heather Main

The day of plenary is the most enjoyable in my view. You don’t need to make the choice between sessions and the judgement on the viability of shifting sessions versus staying put and listening to the slightly less relevant.

ISSCR 2015 plenary was, as to be expected, full of the big names, the affectionately known Rusty (Fred Gage), Jonas Frisen (one of the smartest MD PhDs I have ever met) and of course Shinya Yamanaka. In deciding which talk I wanted to highlight it is somewhat cliché to go for the Nobel Prize winner but I just can’t help it, he is just such a great guy.

I first met Shinya at Karolinska Institutet, Stockholm, Sweden, when he was giving a presentation (no doubt an interview for his Nobel Prize). In association with this trip he was interviewed in our lab space where he divulged that he got into research as he didn’t think he was a very good orthopaedic surgeon, he wanted to do something where he could help people!

So, I was very pleased to see that his ISSCR 2015 talk was divided into 3 sections;

  • immune matching of pluripotent cells
  • differentiation and purification of desired cells types
  • pre-clinical testing of stem cell therapies

What this tells me is that Shinya is truly devoted to helping people. That he is not just thinking about the first step or the last step of stem cell therapies but the entire process, each step as important as the next and the previous. It is not enough that he has a Nobel Prize and could spend the rest of his career studying the mechanisms of reprogramming, he wants to drive his technology to the patients. What a star!

The first part of the talk outlined his work into HLA haplotype matching with regard to homozygous individuals. With a current Japanese focus, just one donor homozygous for the most common HLA haplotype would be sufficient to provide immune matched cells to 10% of the Japanese population. 10 homozygous donors with other common haplotypes would cover 50% of the population and 140 homozygous donors would cover 90%. With 1:1000 individuals showing a homozygous phenotype AT LEAST 140,000 individuals would need to be HLA screened, with this number falling drastically short on the fact that a specific repertoire of HLA haplotypes would be needed. So Shinya and his team are scanning the blood donor and cord blood bank stocks to find their golden donors. A huge task, with huge reward.

For differentiation and sorting Shinya’s team have developed a method called miRNA switch. The technique is mainly aimed at those cell types for which we do not have good cell surface markers for FACS sorting. Basically expression of two fluorescent proteins indicates transfected cells, which upon differentiation to the desired cell type, will lose expression of one of the fluorescent indicators under the control of a cell type specific miRNA. These single positive cells can then be sorted or selected with chemical resistance. Simple and elegant though may require significantly larger numbers of cells, dependant on transfection efficiency.

Finally, my favourite iPSC master showed data from a pre-clinical study into Parkinson’s Disease transplantation of Corin+ dopaminergic neurons. For this section Shinya was very careful to acknowledge his collaborator Professor Jun Takahashi, and continued through the section to present the work as ‘he did’ rather than ‘I did’ or ‘we did’. In the study they were able to show that sorted iPSC derived Corin+ dopaminergic neurons transplanted into monkey brain gave functional recovery of Parkinson’s Disease and survived for at least one year without a reduction in graft size and without tumor formation. Interestingly, whether the original iPSC were from diseased or non-affected individuals, similar rescue was seen, arguing for autologous therapies from the diseased individual. These results were setting up for the exciting step of testing these human cells in human clinical trials beginning within the next 2 years.

While Shinya may be the big name, his humility and genuine desire to make a change in the lives of patients is a great inspiration. His continued dedication to the cause in light of his earth shattering appearance onto the stem cell stage is a testament to a great guy. Japan is definitely the space to watch for a dedication to stem cell therapies (including liberal regulatory standards), and I’m sure along with Shinya they will continue to drive the field forwards both at the basic and clinical level.

Yamanaka Interview on Clinical Use of Pluripotent Stem Cells

Dr. Shinya Yamanaka

Dr. Shinya Yamanaka.                                           Photo from CiRA, Kyoto University

I invited Nobel Laureate Shinya Yamanaka to do an interview on the future of clinical translation of induced pluripotent stem cells (iPSC).

He provides some intriguing new insights into the iPSC field and the broader stem cell arena.

PK: The Takahashi Team’s active Clinical Study using iPSCs to make RPEs to treat Macular Degeneration has generated a great deal of excitement. Can you please share your perspectives on the importance of this work and the team involved? 

SY: This is the first study to apply iPSC technology to human care. This is a very important study, because if it succeeds it will show that iPSCs can be safely used in humans and also their potential for cell transplantation treatment. We collaborated with Dr. Masayo Takahashi of RIKEN CDB by evaluating the safety of the iPSCs and iPSC-derived cells that were used for the cell transplantation. She is an excellent researcher, and I am not surprised that her team is the first to have succeeded in this transplant.

PK: Any cutting edge investigational clinical work such as this has some risks. Could you please comment on the potential risks in this iPSC trial? Are there some elements here such as preclinical data, the number of cells used, or the target tissue of the eye that lower risks?

SY: One of the major concerns is whether transplanted cells such as the RPE sheets will cause tumors. In our collaboration with Dr. Masayo Takahashi’s team, we evaluated the safety of iPSCs and iPSC-derived cells by genome and epigenome analysis. While we minimized the risk to a level acceptable for clinical trials, we really cannot confirm how the cells will respond until we actually do experiments with humans, which is why this project is so important. One advantage of treating age-related macular degeneration is that it is easy to detect any abnormalities in the eyes, which is why the disease is a good starting model for iPSC-based treatment.

PK: As the inventor of iPSCs did you imagine 7-8 years ago that a patient in a clinical study in 2014 would already have received an iPSC-based treatment? How was this rapid translation from bench to bedside possible?

SY: I was surprised that after the announcement of human iPSCs in 2007, Dr. Takahashi told me that she would bring iPSC to the bedside within five years. I thought it possible technically speaking, but doubted it could be done so soon, since we needed to improve the technology and get government approval. It took 7 years, which is remarkable considering the work required. Both the accomplishment and the speed at which it was achieved are testaments to Dr. Takahashi’s leadership and her strong team.

The rapid transition is because many bright and passionate people are in the iPSC field. The funding and infrastructure provided by the Japanese government is also a major factor, as these have encouraged excellent scientists to enter the field.

PK: We are also starting to hear more about Dr. Jun Takahashi’s Team’s important work towards using iPSCs to treat Parkinson’s Disease. Can you please tell us more about that?

SY: Prof. Jun Takahashi’s team at CiRA is working on cell therapy for Parkinson’s disease, aiming to transplant iPSC-derived dopaminergic neural progenitor cells into PD patients’ brains. Early results suggest this treatment can be effective, and his team has established the protocol for transplantation. They are now focusing on validating its safety using monkey models. We hope his work will soon reach the operating room within the next few years.

PK: What other clinical applications of iPSC technology are in the works and that might begin clinical studies in the next few years?

SY: There are two major clinical applications of iPSCs, namely regenerative medicine and drug discovery. CiRA has a number of researchers working on either or both. For regenerative medicine, Prof. Koji Eto at CiRA is working on generating platelets via iPSCs, and we expect this will also proceed to clinical research in a few years. Besides work at CiRA, a team at Keio University has a plan to conduct clinical research on patients with acute spinal cord injury in four to five years, while Osaka University and Keio University hope to transplant iPSC-derived cardiac myocytes into patients with heart diseases within a few years. CiRA is collaborating with these teams as well.

Regarding drug discovery, you may have heard recently of CiRA’s Prof. Noriyuki Tsumaki’s paper about statins effects on bone growth, which was published online in Nature last month.

PK: Some in the media are taking about a certain tension between clinical iPSC work in Japan and clinical iPSC work in the US. Do you believe such a tension exists and if so, why? What does it mean for the iPSC field overall?

SY: I am not sure what “tension” means. I understand that both competition and collaboration exist between the US and Japan.

PK: How do you view hESCs today? Are there hESC clinical trials or potential applications that are of particular interest? What is your view of the argument by some that hESC are no longer needed?

SY: Human ESC was a great discovery for regenerative medicine and also instrumental to the discovery of iPSC and the type of medical treatments we are aiming to apply iPSC. At the same time, the ethical issues that hESC possess mean that as iPSC technology improves, hESC will be less needed. Still, iPSC is a new technology, and its safety and efficacy still needs to be confirmed. In addition, there may be some therapies for which hESC are better than iPSC. Thus, I think basic and clinical research of hESC is also important and should be done in parallel with iPSC research.

PK: What excites you most about the stem cell/regenerative medicine field right now today?

SY: I am excited about the possible number of people treated with iPSCs. This field has great potential to provide treatments for currently incurable diseases. Hopefully, within 5 years, we will refer to Dr. Masayo Takahashi’s AMD work as just one of many patient studies using iPSCs.

PK: Where do you see the iPSC field and the broader stem cell field in say 5-10 years?

SY: It is pretty amazing how much it has changed in the past years, so predicting the next 5-10 years is very difficult. I certainly hope we will see more diseases being treated with iPSC and related technologies such as direct reprogramming. I also hope that iPSC will be used more widely and routinely in drug development.

PK: What advice would you give to young scientists today who are excited about a career in stem cells/regenerative medicine?

SY: Through biomedical research, you could help thousands of patients in the future. Stem cells provide unprecedented opportunities in stem cell therapy and drug development. Biology of stem cells itself is extremely interesting. I hope many young scientists will enter to this field.

Human clinical studies of iPS cells to treat Parkinson’s Disease coming very soon

Jun TakahashiA Japanese team of researchers led by Dr. Jun Takahashi, professor at Kyoto University is reportedly aiming to start in human studies of an induced pluripotent stem (iPS) cell-based treatment for Parkinson’s Disease (PD) as early as fiscal year (FY) 2014.

In Japan the FY runs from April 1-March 31 so FY2014 would begin in about 10 months.

That is still remarkably fast and encouraging in the battle against PD.

It also more broadly is an indication of the accelerating pace with which Japan is aiming to translate iPS cell technology to patients. Jun Takahashi (pictured above in CIRA photo) is part of the larger team working to make iPS cell-based therapies a reality for helping patients.

The Asahi Shimbun article reads:

“We hope to confirm the effectiveness and safety over the coming year or two before proceeding to the stage of clinical research,” Takahashi said during a lecture in Tokyo on June 6.

At Scripps in La Jolla, CA, Jeanne Loring leads another team, this one working with PD patients, working to apply iPS cell technology to treat PD.

I asked Jeanne about this new report of Dr. Takahashi’s plan and have the following quote from her:

I met Dr. Takahashi a few months ago at a CIRM workshop on Parkinson’s disease, and saw some of his very convincing work.  His experiments with transplanting cells in non-human primates supports the idea that dopamine neurons from autologous iPSCs are more likely to be therapeutic.  Since our project plans to transplant patient-specific iPSC-derived dopamine neuron progenitors, this is great news for us. In this case, I don’t feel like this is a competition, and I’m happy to follow in Takahashi’s footsteps.

Dr. Takahashi has published quite a bit on PD’s more generally including treatment of a monkey PD model using a hESC approach that was encouraging from a safety and efficacy standpoint.

I hope we can soon see some of Takahashi’s pre-clinical data on iPS cells for PD published soon so we can get a sense of the safety and other information.

Overall this seems like very good news for the stem cell field and Parkinson’s Disease community.