Without a doubt one of the most important tasks set to medical scientists is the development of more efficacious treatments and even cures to common forms of cancer.
I've had me eye on breakthrough research for a while now, and this seems to me to be one of the most promising new developments for quite some time. It's still a ways from a final 'cure-for-all' cancers, but with a bit of luck and some more detailed research, we could be well on our way.
Hybrid virus may help fight cancer
Local scientists find that it shows promise as a way to target tumors
By ERIC BERGER
Copyright 2006 Houston Chronicle
Using the cell-invading prowess of viruses and the hybrid concepts driving up automobile fuel efficiency these days, local scientists have found a way to light up cancerous tumors in mice like fireflies in the night.
What sounds like a genetics parlor trick may be an important step toward identifying cancer cells and zapping them before they spread and smother healthy organs.
By creating a hybrid out of two dissimilar viruses, researchers hope to be able to illuminate tumor cells, making it easier for doctors to target cancers and monitor treatments.
It also could provide a kick-start to the unfulfilled promise of gene therapy.
"This really bridges a big gap," said Renata Pasqualini, a professor of medicine and cancer biology at The University of Texas M.D. Anderson Cancer Center, co-leader of a study published in Friday's issue of the journal Cell.
That gap — the successful delivery of genes into cells — has been the primary reason medical researchers have failed to get gene therapy to live up to its potential.
Genes, the carriers of hereditary information, signal a body's cells when it's time to manufacture certain proteins. These proteins carry out the basic biologic functions of life.
Scientists long have thought that inserting normal genes into cells to replace the function of defective genes, such as restoring insulin production in the case of diabetics, could treat diseases.
But they have struggled to capitalize on the trove of information on the 25,000 human genes accumulated in the past decade, largely because of the delivery problem.
Viruses by nature attack human cells to introduce their genes into the host cell for the purposes of replicating and spreading throughout the body. Scientists already have tapped that ability.
But viruses have proved to be imperfect carriers of "good" genes because they attack human cells indiscriminately, both the healthy and cancerous. Moreover, the body's immune system often is good at destroying these viruses before they reach their targets.
These shortcomings have led scientists to look a little further down the food chain to viruses that infect bacteria. Such viruses are found everywhere, from soil to the human gut.
Bacterial viruses can be targeted very specifically to different types of cells. But because they've evolved to infect bacteria, these viruses do a poor job delivering good genes into human cells.
What's a biologist to do? Combine the best features of both viruses into one.
The hybrid virus created by Pasqualini and her colleagues at M.D. Anderson infected nearly 100 percent of the targeted cancerous cells, and the genes they delivered functioned for weeks or even months, a stunning success. The delivered genes produced fluorescent proteins that the researchers could easily see with imaging equipment.
With the new technique, Pasqualini said, it could be possible for cancer doctors and their patients to know almost immediately whether chemotherapy and other treatments are having any effect on tumors.
It's worth noting, however, that there have been past successes with small animals that haven't translated into larger mammals or humans.
"This is only a proof-of-concept" cautioned Dr. Wadih Arap, a co-leader of the study along with Pasqualini.
Still, the research has garnered the attention of other cancer scientists. Not only does it appear to have solved the problems of targeting and delivery, but the hybrid virus seems to evade the body's immune system long enough to deliver its genetic payload.
"I have a lot of excitement for this new approach," said Dr. Steven Libutti, a senior investigator at the National Cancer Institute and head of its Tumor Angiogenesis Section.
Libutti and other researchers are testing the hybrid virus in dogs with cancerous tumors. In the study, Libutti has begun using the hybrid virus to transport genes that produce a protein-like material that's toxic to cells that line blood vessels leading to tumors. Kill the blood vessels and the tumor starves.
Performing the study in large animals is the final step before the hybrid virus can be tested in humans, possibly within a few years.
"We've treated the first dog in this study without any toxicity," Libutti said. "We should know soon whether the new approach works, but we're very hopeful."
Source: http://www.chron.com/disp/story.mpl/front/3811517.html
There are some potential problems, such as whether this protein attacks normal blood vessels or just focusses on angiogenesis (the development of new blood vessels to feed tumors), among others, but it's off to a good start.
If you want a copy of the journal paper published in The Cell, or a brief synopsis of their findings, let me know and I'll provide it for you. If you'd like to know more about how scientists use viruses to treat cancers, I'll give you a brief run-down on that too. If you don't care, atleast cross your fingers with me while we wait and see if this treatment lives up to its promise.
I've had me eye on breakthrough research for a while now, and this seems to me to be one of the most promising new developments for quite some time. It's still a ways from a final 'cure-for-all' cancers, but with a bit of luck and some more detailed research, we could be well on our way.
Hybrid virus may help fight cancer
Local scientists find that it shows promise as a way to target tumors
By ERIC BERGER
Copyright 2006 Houston Chronicle
Using the cell-invading prowess of viruses and the hybrid concepts driving up automobile fuel efficiency these days, local scientists have found a way to light up cancerous tumors in mice like fireflies in the night.
What sounds like a genetics parlor trick may be an important step toward identifying cancer cells and zapping them before they spread and smother healthy organs.
By creating a hybrid out of two dissimilar viruses, researchers hope to be able to illuminate tumor cells, making it easier for doctors to target cancers and monitor treatments.
It also could provide a kick-start to the unfulfilled promise of gene therapy.
"This really bridges a big gap," said Renata Pasqualini, a professor of medicine and cancer biology at The University of Texas M.D. Anderson Cancer Center, co-leader of a study published in Friday's issue of the journal Cell.
That gap — the successful delivery of genes into cells — has been the primary reason medical researchers have failed to get gene therapy to live up to its potential.
Genes, the carriers of hereditary information, signal a body's cells when it's time to manufacture certain proteins. These proteins carry out the basic biologic functions of life.
Scientists long have thought that inserting normal genes into cells to replace the function of defective genes, such as restoring insulin production in the case of diabetics, could treat diseases.
But they have struggled to capitalize on the trove of information on the 25,000 human genes accumulated in the past decade, largely because of the delivery problem.
Viruses by nature attack human cells to introduce their genes into the host cell for the purposes of replicating and spreading throughout the body. Scientists already have tapped that ability.
But viruses have proved to be imperfect carriers of "good" genes because they attack human cells indiscriminately, both the healthy and cancerous. Moreover, the body's immune system often is good at destroying these viruses before they reach their targets.
These shortcomings have led scientists to look a little further down the food chain to viruses that infect bacteria. Such viruses are found everywhere, from soil to the human gut.
Bacterial viruses can be targeted very specifically to different types of cells. But because they've evolved to infect bacteria, these viruses do a poor job delivering good genes into human cells.
What's a biologist to do? Combine the best features of both viruses into one.
The hybrid virus created by Pasqualini and her colleagues at M.D. Anderson infected nearly 100 percent of the targeted cancerous cells, and the genes they delivered functioned for weeks or even months, a stunning success. The delivered genes produced fluorescent proteins that the researchers could easily see with imaging equipment.
With the new technique, Pasqualini said, it could be possible for cancer doctors and their patients to know almost immediately whether chemotherapy and other treatments are having any effect on tumors.
It's worth noting, however, that there have been past successes with small animals that haven't translated into larger mammals or humans.
"This is only a proof-of-concept" cautioned Dr. Wadih Arap, a co-leader of the study along with Pasqualini.
Still, the research has garnered the attention of other cancer scientists. Not only does it appear to have solved the problems of targeting and delivery, but the hybrid virus seems to evade the body's immune system long enough to deliver its genetic payload.
"I have a lot of excitement for this new approach," said Dr. Steven Libutti, a senior investigator at the National Cancer Institute and head of its Tumor Angiogenesis Section.
Libutti and other researchers are testing the hybrid virus in dogs with cancerous tumors. In the study, Libutti has begun using the hybrid virus to transport genes that produce a protein-like material that's toxic to cells that line blood vessels leading to tumors. Kill the blood vessels and the tumor starves.
Performing the study in large animals is the final step before the hybrid virus can be tested in humans, possibly within a few years.
"We've treated the first dog in this study without any toxicity," Libutti said. "We should know soon whether the new approach works, but we're very hopeful."
Source: http://www.chron.com/disp/story.mpl/front/3811517.html
There are some potential problems, such as whether this protein attacks normal blood vessels or just focusses on angiogenesis (the development of new blood vessels to feed tumors), among others, but it's off to a good start.
If you want a copy of the journal paper published in The Cell, or a brief synopsis of their findings, let me know and I'll provide it for you. If you'd like to know more about how scientists use viruses to treat cancers, I'll give you a brief run-down on that too. If you don't care, atleast cross your fingers with me while we wait and see if this treatment lives up to its promise.
