Just to remind the world that the UK isn't behind in science (vis-a-vis the US), the British High Commission probably decided that this exhibition panel was important to remind everyone of the UK's key scientific achievements.
So, if you didn't already know or can't read the words in the picture, here's three that you might have confused as a US invention...
UK GREATS
1953: Discovery of structure of DNA
1978: Birth of first test-tube baby
1985: Discovery of hole in Ozone layer
1990: Invention of World Wide Web (bet you all thought this was from the US!)
Anyway, I mentioned in my last post that I'd tell you a bit about what I learned in the symposium. My apologies for the delayed write up.
The first lecture after lunch was by Professor Tariq Enver, Professor of Stem Cell Biology at Oxford and Director of Stem Cell Research at the MRC's Molecular Haematology Unit in the Weatherall Institute for Molecular Medicine.
Prof. Enver's talk was of interest to me for 2 reasons - inspiring content AND all the key ingredients of a good presentation:1. Clinical relevance (patient's photos to inspire the right emotional context)
2. Clear introductory statistics for the uninitiated
3. Direct genetic implications of the research
4. A happy conclusion (very important)
WHAT IT WAS ABOUT
The story begins with the introduction of stem cells and their existence in babies' blood. The first question he posed to the audience was whether anyone knew what a "Guthrie card" was (when a baby is born, a small heel prick is performed to obtain the baby's blood, which is stained on a filter paper- known as a Guthrie card- and used to test for inborn metabolic diseases). Prof. Enver suggests that Guthrie cards can be kept for extended periods of time so that if a child is later found to develop certain types of leukemia, it would be possible to identify whether the indications of leukemia were there at birth.
WHY IS THIS IMPORTANT?
The reason why it is useful to know whether the leukemic cells are present at birth, is because if the cells are present at birth, doctors may choose to treat the patient with different medications as leukemic cells (which behave like stem cells) have different chemo-sensitivities in children. Leukemic cells from birth may require more specific and less intensive drugs than adult patients.
At this point, I feel that it is important to point out the difference between "stem cells" and what is popularly termed "cancer stem cells".
Stem cells are cells which exist in the body and are responsible for continuous maintenance of the body and a controlled replacement of our cells and tissues. The stem cells are known to be "relatively immortal" (ie they live a far longer lifespan than our normal cells, which may die after 7-90days) and are key to our existence and survival of our blood and immune systems etc.
Cancer stem cells however, are like other cancers -cells gone wrong- except that the cell that has gone wrong is the stem cell. Hence, the cancer stem cell does not make other tissues and does not replace cells like it should. It merely makes more of itself, which isn't useful under the normal circumstances.
So, a pertinent question to ask is how do you know a stem cell from a cancer stem cell? Well, Prof Enver believes that there is a lot of talk about "markers" for stem cells, but there is no doubt that these markers have a long way to go in being defined and that the best way to know is to conduct functional studies (ie, to see how the cells really work in real life).
REAL LIFE SCENARIO
A pair of very beautiful twin girls from Bromley a city in Kent, were the subjects of the study. According to the news story, which was reported in January this year, Olivia Murphy developed acute lymphoblastic leukemia (ALL) when she was 2 years old, while her twin sister Isabella remained healthy. I'm not exactly sure how the case came to Prof. Enver's attention at the MRC (I wanted to ask him but didn't get a chance) but he and his group ended up researching why one of the twins developed the disease while the other remained healthy. Prof. Enver's team elucidated that both twins carried a gene that pre-disposes them to developing the ALL, but while Isabella only had one hit to her gene, Olivia had two hits which resulted in cancer development (cancer usually results from several mutations to certain genes which allow the cells to grow uncontrollably).
They proved to be the perfect research subjects to understand if genetics had a pivotal role in the stem cells, which could already be susceptible to chance changes after birth. The aim of the research, was to discover where the point of change was that resulted in the cancer, and whether it would be possible to design a method to protect the susceptible genes (prevention) or necessary drugs which would target the cancer cells.
There was a more detailed write up which describes how the twin's parents brought Olivia in for fever which the doctors had then thought was tonisilitis. The parents insisted on a blood test and were given the ALL diagnosis. Fortunately, Olivia's cancer responded well to the chemotherapy and was a success, but not without side effects.
The chemotherapy was so strong that her immune system was damaged and she suffered six attacks of shingles (chicken pox relative) which infected her eye and blinded it. In the course of research, Prof. Enver's team took regular samples of both the girls' blood and the doctors will screen Isabella regularly to monitor any signs of the 'second hit'.
OPTIMISM FOR TARGETING PRE-CANCER CELLS
According to Prof. Enver, as the total cancer relies on less than one per cent of the cancer generating cells to maintain the disease, this offers a unique opportunity to develop better drugs to kill off this one per cent of cells. He was quoted saying that there could be a day where the prevention of leukemia would be possible as the pre-leukemia cells could be eliminated at the source, potentially curing 90% of the cases detected.
However, no medical procedure is risk free and the strong chemotherapy may result in the death of 1-2% of cases treated. And for those couples with identical twins, you might like to know that nine out of ten children who have an identical twin with leukemia do not develop the disease.
That means that Isabella's chances of staying cancer free remains pretty high. :)
Posts
No comments:
Post a Comment