Cancer vaccine breakthrough using 'cold' virus
Scientists claim to have overcome a major hurdle in their work on finding a way to wipe out cancer with viruses.
Scientists suggest the reovirus, which usually causes mild colds or stomach upsets, has the power to shrink tumours.
They have created the viral vaccine that can be injected into the bloodstream, "hitching a ride" on blood cells and avoiding the immune system.
Previous research has focused on injecting the virus into tumours.
The reovirus treatment acts both like chemotherapy and a vaccine. It kills tumour cells while at the same time causing an anti – cancer immune response.
Dr Kevin Harrington, from the Institute of Cancer Research in London who co – led the study, said: ''Viral treatments like reovirus are showing real promise in patient trials."
''This study gives us the very good news that it should be possible to deliver these treatments with a simple injection into the bloodstream.
It would have been a significant barrier to their widespread use if they could only have been injected into the tumour, but the finding that they can hitch a ride on blood cells will potentially make them relevant to a broad range of cancers."
He added: ''We also confirmed that reovirus was specifically targeting cancer cells and leaving normal cells alone, which we hope should mean fewer sideeffects for patients.''
Scientists had feared that immune system antibodies in the blood would mop up the viral particles, preventing them from reaching their target.
Instead, the viruses evaded the immune system by hitching a ride on red blood cells. The discovery could pave the way to viral therapies one day becoming a standard form of cancer treatment.
Dr Julie Sharp, from the charity Cancer Research UK which part-funded the research, said: ''This promising study shows that reovirus can trick the body's defences to reach and kill cancer cells and suggests that it could be given to patients using a simple injection.
''We look forward to seeing how this research develops and if this could one day become part of standard cancer treatment.''
The research involved a small group of 10 patients with bowel cancer tumours that had spread to the liver. Patients were given up to five doses of reovirus over a period of a few weeks before they were due to have surgery.
Blood tests shortly after the treatment showed the active virus associated with blood cells. Tissue removed during surgery revealed ''viral factories'' in the tumour, but not normal liver tissue.
Reovirus is an extended family of viruses including rotavirus, which can cause stomach upsets.
The study was published in the journal Science Translational Medicine.
Adapted from: http://www.telegraph.co.uk/health/healthnews/9330265/Cancer-vaccine-breakthrough-using-cold-virus.html
Adapted from:http://www.uthscsa.edu/mission/ArticleData/2008-07/images/reovirus.jpg
Reflections
I feel very happy that there is finally a glimmer of hope in recovering for cancer patients. Cancer has always been a disease which signals death is approaching and rarely are there anyone who manages to fully recover from it. Even if they do, they must have went through tough chemotherapies and surgeries. However, now with this discovery, it could be as simple as just injecting the reovirus viral vaccine into cancer patients' bloodstreams, which acts both like a vaccine, killing the tumour cells and also, a chemotherapy, causing a anti-cancer immune response. Now, with this discovery, when it is placed into use in future, it would have lesser side effects than the treatment now, which means that this if put into use would be very beneficial to us in terms of helping us kill tumour cells. I would hope that this discovery would progress towards the better so that it can be confirmed for its effectiveness or improved on its effectiveness and put into use if it is proved to not do harm to our body instead.
However, since the virus can cause stomach upset and it is realised that they can hitch a ride on red blood cells and avoid the immune system, it would be possible that they may create mayhem in our body instead of helping us. Therefore, to a small extent, using the reovirus viral vaccine to kill tumour cells may not be the right choice to make.
Bacterium Transforms Into Weapon Against Sleeping Sickness
ScienceDaily (Aug. 30, 2012) —
Scientists of the Antwerp Institute of Tropical Medicine (ITG) opened a new front against the cause of sleeping sickness. This parasite is transmitted between humans by tsetse flies. The researchers learned a bacterium living in those flies how to produce antibodies against the parasite. Application in the field is still a long way of, but the technique shows quite some promise.
Sleeping sickness is caused by trypanosomes, parasites being transmitted by the bite of a tsetse fly.
The World Health Organization estimates the yearly death toll at between 10,000 and 20,000 people. On top of that, the parasite also infects cattle, causing considerable economic loss. Many small African farmers depend on their cattle.
Without treatment, an infection is irrevocably fatal. Unfortunately, many poor people present at the hospital only in a late stadium. At that time the Trypanosoma parasites have lodged themselves in the brain, behind the notorious blood-brain barrier that keeps most drugs out. Arsenic compounds can pass the barrier and kill the parasite, but they also kill five per cent of the patients. New drugs are not in the pipeline.
Besides the parasite, one may also attack its vector, the tsetse fly. But insecticides may be detrimental to the environment, certainly in the long run. Therefore scientists look for alternative strategies. For instance genetically modified insects that are incapable of being infected by the parasite, or do not transmit it. But germline transformation of tsetse flies is unfeasible. To do so, one must be able to handle the eggs, but tsetse flies do not lay eggs, they directly bring forth a larva.
Therefore, the Antwerp researchers took another road. Tsetse flies harbour, as is the case with many insects, resident bacteria. One of them, Sodalis glossinidius (literally: companion of the tsetse fly) exclusively lives in tsetse flies. And it can be cultivated in the lab. De Vooght was the first to genetically modify the bacterium so it produces, and excretes, a very efficient type of antibody, called a nanobody. She identified two different secretory pathways that transported the nanobodies out of the bacterium. She also demonstrated that the bacterium was not hampered by its modification, so it can stand its ground amidst non-modified, 'wild type' congeners inside the fly.
Next, with antibiotics she cleared tsetse flies of their wild type bacteria and replaced those by the modified bacteria. These successfully colonized the flies and started producing nanobodies. The nanobodies also were present in the midgut, where the sleeping sickness parasite also is to be found.
De Vooght demonstrated the feasibility of the technique, but it still needs some development before it can be used to control sleeping sickness in the field. For instance, the antibodies now produced by the bacteria, are directed against a form of the parasite occurring in humans, not in flies. This is simply because this antibody was available, while the one against the fly form still has to be developed. De Vooght: "We wanted to demonstrate first that the technique works in principle. Now we have achieved that, we can tackle the technical details."
To the scientists it is just as important that symbiotic bacteria producing all kinds of substances are a means to getting insight into the interactions between disease-causing organisms and their insect vectors. The Antwerp researchers already demonstrated that the sleeping sickness parasite interferes with the saliva production of tsetse flies, forcing them to bite more humans than they otherwise would do. Insight in that kind of interactions might be instrumental to opening new ways of attacking diseases.
Adapted from: http://64.19.142.12/upload.wikimedia.org/wikipedia/commons/thumb/5/54/Tsetsemeyers1880.jpg/220px-Tsetsemeyers1880.jpg
Reflections
When I went back to primary school last year's December, I came upon this signboard with the details of some creepy crawlies and bugs. It was my first encounter with this insect, the tsetse fly and I realised that it could deal large amount of damage, causing lots of people to die due to implications from the sleeping sickness. From then, I thought about the people staying at Africa, where the fly is found, who has contracted the disease and even died from it and when would their suffering end from this small tsetse fly that caused so much misery. Finally, with Science help, there is finally a way. I feel glad to know that they now would have a way to greatly reduce the threat posed by the tsetse fly.
I realised that with Science, almost nothing is impossible and if you have the will, you have the way. Kudos to the scientists!
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