Brain tumour following neural stem cell transplant
February 23, 2009
A disturbing case report was published this week in the journal PLOS Medicine. A boy afflicted with ataxia telangiectasia, a rare neurodegenerative condition that affects motor and speech control, had received multiple neural stem cell transplants in a Moscow hospital starting in the year 2001. The transplants involved taking fetal neural stem cells and injecting them into the patient’s brain and spinal cord, in the hope that the cells would integrate properly and alleviate some disease symptoms. By 2005 the boy was suffering from severe headaches with led doctors to investigate and identify abnormal growths in his brain and spinal cord. The spinal cord tumour was subsequently removed, and through a range of genetic tests it was conclusively shown that the tumour originated from the injected stem cells. The stem cells meant to alleviate his condition had in fact developed into life-threatening tumours.
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The Birth of Cancer Stem Cells
February 20, 2009
A little over a decade ago, something happened here at SickKids: the field of cancer stem cell biology was born. In 1994, John Dick’s group published a seminal study in the journal Nature, announcing the identification of human acute myeloid leukemia (AML)-initiating cells.
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Time to catch up on your stem cell reading
February 20, 2009
I read an interesting article in Time magazine today. The article “Stem Cell Research: The Quest Resumes” appeared in the February 9th issue of Time, and is freely available on-line. By focusing the story around one prominent researcher who is driven to help his two diabetic children through a stem cell-based therapy, the journalist does a nice job of capturing the very personal nature of research into human disease.
Although brief, the article manages to touch on a number of important topics in stem cell research; the political and scientific repercussions of the current funding restrictions on human ES research, the evolving research around induced pluripotent stem cells (iPS), and the methods by which these discoveries may be applied to help patients overcome disease. If you have a minute, check out the article, it’s a nice introduction to the topic of stem cell research for those who need it, yet still contains some interesting facts for those who follow the field a little closer.
The truth hurts
February 12, 2009
The truth often hurts….but everyone seems to prefer a painful truth over a happier, yet more deceptive statement or position. In current politics it seems that at least some of Obama’s popularity is due to the perception that he is presenting a more level, or truthful assessment of the current economic and political issues that are occurring world-wide. Indeed it seems to be part of the political strategy right now to separate the Obama team from past administrations by being completely candid and frank.
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Another stem cell first: Clinical trial using human embryonic stem cells is approved
January 27, 2009
A biotechnology company from the United States has recently announced that they have received approval to initiate the world’s first clinical trial involving human embryonic stem cells (hES). Geron announced on January 23rd that their application for the company’s Investigational New Drug (IND) application for the clinical trial of GRNOPC1 in patients with acute spinal cord injury had been accepted.
Breakthrough of 2008 - Reprogramming
January 26, 2009
In December 2008, the scientific journal Science, named the incredible process of stem cell reprogramming breakthrough of the year 2008. Reprogramming is the reversal of the state of a somatic cell (i.e. a differentiated cell or a cell that has become a skin cell or kidney cell) back to a state reminiscent to that of a pluripotent state (i.e. an embryonic stem cell).
A New Era for Disease Modeling and Drug Screening
December 29, 2008
Induced Pluripotent Stem (iPS) cells are cells that have been reprogrammed from skin fibroblasts back to a state reminiscent of Embryonic Stem (ES) cells. Human iPS cells were first discovered back in November 2007 by pioneer Dr. Shinya Yamanaka at Kyoto University (reported in scientific journal Cell in November 2007). iPS cells are thought to hold the same potential as ES cells in regenerative medicine such as disease modeling, drug screening, and cell replacement therapy, but with additional advantages as it bypasses the ethical issues relating to the use of human embryos.
Cancer Stem Cells: Fact or Fiction?
December 26, 2008
In the 1960s there was an unethical experiment where physicians took cancer cells from various types of malignancies and re-injected these cells back into the original cancer patient or another non-cancerous terminally ill patient.i The results from this experiment suggested that those with cancer lacked immunity to the disease while “healthy” individuals carried some immunity to the cancer cells. However, another interesting observation was made throughout the experiments: that it requires millions of cancer cells to initiate the growth of a tumor. It is this observation from which two theories emerged in the decades to come regarding tumor initiation and maintenance.
Returning home…
December 20, 2008
My blog this month is about returning home. I am an ex-pat Australian working in stem cell research at SickKids. I left Australia on Australia Day 2004 as a fresh-faced PhD graduate. Nearly 5 years have passed and I have returned this month for a brief trip in the capacity of both a mature researcher and as an aunty to see my kids for Christmas.
I won’t lie; the past few months have been interesting for me as I struggled to put all of my emotions in perspective. I have been full of joy and happiness, a little anxious and fearful, but proud as well, which has made for some very interesting internal dialogues! It took a little time to realise these feelings were not about my return home after so long away, but rather they are indelibly linked to life as a researcher, regardless of the stage at which we find ourselves in our careers.
I am at the point in my career where I am almost ready to strike out for independence, and I came home to look at research opportunities. My search started with giving a seminar to my home institution; that is to those responsible for giving me my foundations in science. This seminar was important to me as much for showcasing the stem cell research we are doing at SickKids with respect to childhood cancer as it was for showing that living abroad and working in an environment that fosters collaborative efforts, as SickKids does, has been a great developmental opportunity. I was able to illustrate that as a result of the information we have gained from the cancer stem cell research we are doing we could offer insight into why current therapies are not working, the mechanisms of responsible for patient relapse at distant metastatic sites, and how we might treat them in the future.
I was fortunate to give this seminar to a second children’s research institute and talk to more Australian scientists about the stem cell research being done at SickKids and to some other scientists interested in finding out what we are doing at SickKids. The response to my research in the role of cancer stem cells in children’s cancer was incredibly positive for both the application of stem cell research theories to children’s cancer, particularly a cancer where distant metastases are common and responsible for a majority of deaths, as well as the collaborative efforts of the team (the ward, pathology, surgery, clinic, and research) at SickKids as model system.
Stem cell research is an interesting research area in so many ways, but none more interesting for me at this stage in my career as I look for the right place to settle and establish myself as a stem cell researcher. SickKids have put me in the right place with respect to being competitive in attracting career offers and research funds to continue my efforts in trying to understand the role of cancer stem cells in childhood cancer.
I am happy about my experience of returning home to tell my very early career mentors about how I have developed as a scientist since I left them, and have made some really tough career and life decisions in this too short a trip. I’d like to continue this blog to tell you all about the process a young scientist goes through to make the decision to become an independent researcher and to tell you about the process of looking for the right job.
Talk to you next month and Merry Christmas!
Luck
December 16, 2008
I had a very lucky week; I was hit by a car.
Last Tuesday night I was walking along a busy downtown street. As I crossed the intersection, a car sped around the corner, struck me, and threw me to the ground. Just a moment before I was hit, I saw the headlights of the car only inches from my knee. Amazingly, the Hollywood clichés about time slowing down seem true. As I was hit, many thoughts went through my mind as if the impact was occurring in slow motion. I thought, “but the light isn’t even yellow, why is the car here in the crosswalk”? Then, “boy, it’s lucky this isn’t a big truck with those steel cages on the front”. I even thought, “damn, this is going to hurt”. But, part of my mind was still a stem cell biologist as I thought, “I hope I don’t snap my spine, because stem cell transplants are not ready yet."
Rett Syndrome and induced Pluripotent Stem cells goes “Green”
June 17, 2009 by Aaron Cheung
Stem cell researchers at The Hospital for Sick Children have now devised a method, reported in the scientific journal Nature Methods, that will facilitate the generation of induced Pluripotent Stem (iPS) cells. I have previously blogged about the promise of iPS cells (see related articles). iPS cells are cells which have been reprogrammed from a differentiated somatic cell (such as your skin cells) to a pluripotent stem cell (like an embryonic stem cell, only that you don’t need to use embryos!). The generation of iPS cells is inherently very rare which occurs at a frequency of about 0.01% meaning you can generate about one iPS cell line out of hundred thousand cells. Out of which, many lines fail to satisfy the different rigorous tests necessary to be given the prestigious name of “iPS cell”.
Continue reading Rett Syndrome and induced Pluripotent Stem cells goes “Green”
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Stem Cell Origins
Cancer stem cells
Stem Cells and the Nervous System
