Wednesday, July 25, 2007

Virus vs. Cancer: Reolysin Reovirus in Multiple Human Trials

Viruses are hardy pre-lifeforms, that have played a major role in the evolution of humans and other animals and plants. The articles featured in this posting deal with the reovirus labeled Reolysin, by Canadian company Oncolytics.
The novel anti-cancer therapy, REOLYSIN®, is a living virus, not a chemotherapy drug, that is toxic to cancer cells but not harmful to normal cells. This novel therapy, using a living virus, is the first of its kind available at CTRC.

...“This novel therapy has shown success because the reovirus replicates in and destroys the cancer cells within the patient’s body,” said Mita. “Cancer cells have several molecular and genetic abnormalities. In normal, healthy cells, the reovirus is unable to reproduce because of an enzyme named PKR. The enzyme is suppressed in cancer cells, and therefore the reovirus can replicate in the cancer cell and kill it.”

“REOLYSIN® typifies the true targeted therapy approach that seeks to use fundamental differences between cancer and normal cells as the basis for effective anti-cancer approaches and we are thus very excited about the this study,” said Francis Giles, MD, director of the CTRC Institute for Drug Development.
From article discussing human trials of Reolysin for metastatic sarcomas to the lung.

Another trial is ongoing in the UK:
The trial (REO 010) has two components. The first is an open-label, dose-escalating, non-randomized study of REOLYSIN(R) given intravenously with docetaxel every three weeks. A standard dosage of docetaxel will be delivered with escalating dosages of REOLYSIN(R) intravenously. A maximum of three cohorts will be enrolled in the REOLYSIN(R) dose escalation portion. The second component of the trial will immediately follow and will include the enrolment of a further 12 patients at the maximum dosage of REOLYSIN(R) in combination with a standard dosage of docetaxel.

Eligible patients include those who have been diagnosed with advanced or metastatic solid tumours such as bladder, prostate, lung or upper gastro-intestinal cancers that are refractory (have not responded) to standard therapy or for which no curative standard therapy exists. The primary objective of the trial is to determine the Maximum Tolerated Dose (MTD), Dose-Limiting Toxicity (DLT), recommended dose and dosing schedule and safety profile of REOLYSIN(R) when administered in combination with docetaxel. Secondary objectives include the evaluation of immune response to the drug combination, the body's response to the drug combination compared to chemotherapy alone and any evidence of anti-tumour activity. This is the third trial beginning in 2007 that is examining the role of REOLYSIN(R) in combination with standard chemotherapeutics.

An animal model study using childhood sarcoma cell lines demonstrated significant activity of Reolysin against childhood sarcomas.

Particular viruses can be very useful for treating human disease, and eventually for augmenting normal human function and lifespan. That is because viruses have evolved to be excellent gene therapy vectors, and clever cell sneaks. Viruses can slip into cells and into cell nuclei, and have their way with the cell and its transcriptional apparatus--before the cell is even aware that anything has changed.

Viral therapies have the potential to be misused or misdirected, just like any other revolutionary approach to medicine and life extension. But it is important to understand that the tools that viruses bring to the table are significant, and are the result of billions of years of viral/cellular co-evolution.

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Monday, July 23, 2007

More on Resveratrol

Scientists at Harvard and MIT have added to the "Resveratrol mystique." Their research adds weight to the Resveratrol::Sirt1 connection, and suggests that Resveratrol may be useful in preventing neurodegenerative diseases such as Alzheimer's.
The scientists have shown that a gene called SIRT1 and a plant compound found in red wine called resveratrol can protect against neuron degeneration in a mouse model of Alzheimer's disease and amyotrophic lateral sclerosis. The researchers demonstrated that activating SIRT1 and injecting resveratrol, which have both been previously associated with life-span extension in lower organisms, can also prevent cognitive problems in the mice.

The mice used in the study develop an approximation of human neurodegenerative disease over a period of weeks. As neurons in their brains die and lose connections, their spatial learning is impaired, and the mice develop difficulty associating cause and effect. Treatment with resveratrol reduced the death and degeneration of neurons in these mice and also restored their learning abilities to a level comparable to that of normal mice not suffering neurodegeneration. "Thus, resveratrol is not only neuroprotective, it also improves cognitive function after severe neurodegeneration," says Li-Huei Tsai, the professor of neuroscience at MIT who led the research with David Sinclair, a professor of pathology at Harvard. Tsai says this improvement in function suggests that resveratrol has potential for treating human neurodegenerative diseases.

....The study is the first to suggest that resveratrol could actually improve cognitive function in patients with neurodegenerative diseases. "Generally, SIRT1 has been observed to be neuroprotective," says Leonard Guarente, the professor of biology at MIT who uncovered the connection between life span and the yeast equivalent to SIRT1 about 10 years ago. What's new about Tsai and Sinclair's work, he says, is its demonstration that activating SIRT1 prevents cognitive decline in mice with neurodegenerative disease. The study shows that "resveratrol can protect against memory loss and learning decline," says Guarente, who was not involved with the research.

Guarente says the study suggests that compounds that can activate SIRT1 could be used to treat neurodegenerative disease in humans as long as they can pass through the blood-brain barrier. This membrane surrounding and protecting the brain from chemicals in the blood presents a major challenge to any researcher developing drugs that target the brain. Mice in the study received injections of resveratrol directly into blood vessels in their brains, which would not be practical in human patients.

This type of regenerative gene control via phyto-nutrients is particularly encouraging, given the most famous source of the nutrient is red wine.

Resveratrol and other phyto-nutrients have significant potential to benefit an aging population in the developed world--far beyond whatever in vivo anti-oxidant activity they may possess. The particular mechanisms of their beneficial potential is yet to be worked out.

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Wednesday, July 04, 2007

Care for a Brand New Thymus?

Japanese scientists have built an artificial "lymph node" from thymus tissue, and transplanted it into immunodeficient mice.
The researchers, from RIKEN's Research Center for Allergy and Immunology in Yokohama, constructed their mouse aLNs by impregnating a two- to three-millimeter-diameter scaffold of the fibrous structural protein collagen with connective tissue extracted from the thymus of newborn mice and dendritic cells. Earlier work suggests that it is the connective tissue stromal cells which organize the structure of lymph nodes.

The aLNs were initially implanted into mice with a normal, healthy immune system, which had previously been injected with a harmless antigen compound to trigger an immune response. So the aLNs became populated with immune system T-cells and B-cells which specifically recognize and counter germs or cancer cells expressing the injected antigen.

These primed aLNs were then transplanted into two sets of mice--a group with a normal immune system which had never been exposed to the antigen, and a group in which the immune system did not function. When then exposed to the antigen both groups responded immediately by making appropriate protective antibodies--and the response to the antigen lasted for longer than four weeks, which means immune cells which retained 'memory' of the antigen had been generated.

Further investigation of the immunodeficient mice showed that T- and B-cells from the aLNs migrated to their spleens and bone marrows and were there generating large numbers of antigen-specific antibody-forming cells. The results also revealed some of the compounds involved in directing this migration process.
This research has implications for the study of treatments for immune diseases, cancer, aging, and infectious disease such as AIDS. Thymosin is one of the several hormone levels that falls abruptly in the aging human. Growing an artificial thymus to boost thymosin levels appears within reach, if proven to be beneficial.

Also, here is a free collection of articles on Nanotechnology in Cancer.

And, here is more on an improved method for cervical cancer screening.

Better screening and better treatments. The two need to go hand in hand. Add better prevention to the mix and you are getting somewhere.

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