nos-trum. pronunciation: \nos'-trum\. noun. Etymology: Latin, neuter of noster our, ours.
1. a medicine of secret composition recommended by its preparer but usually without scientific proof of its effectiveness.
2. a usually questionable remedy or scheme.
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Monday, August 2, 2010

STUDY: Using Herpes To Treat Cancer

Interesting twist on cancer therapy:  use modified herpes virus to attack tumor cells.

I saw this note in the BBC News health blog (Aug 1) about some researchers who treat head and neck cancer.  So, I went to the original research  in the August issue of Clinical Cancer Research to see what the science was all about.

First, this is a work in progress.  More work needs to be done, but the idea is one that's rarely been tried:  take a infectious disease agent--one that normally causes a wide-spread infection in humans--modify the genetic code of the organism (in this case, a virus) so that it can no longer infect normal human cells, but can infect tumor cells.  Viruses infect cells by penetrating the cell membrane; the process requires that the virus have an intact mechanism to attach itself and open a gap into the cell to insert its genetic code.

If you damage or modify the virus's genes in such a way that the mechanism for infecting cells doesn't work any more, no infection can occur.  Why?  Because viruses can only reproduce from the interior of the cell they infect; viruses don't have all the resources to synthesize the components to reproduce themselves.  They have to steal from the cell they infect.  As they reproduce in the cell, they kill the cell.

So, unable to penetrate -> unable to multiply -> no infection.

In this study, they changed the herpes virus's ability to enter a cell so that it retained the ability to enter tumor cells only.  A neat trick.

This way the herpes virus kills the tumor cells they infect.  If you add standard chemotherapy to the treatment, theoretically it would improve the results...and maybe obtain more cures.

Caveat:  head and neck cancer are not common types.  So we're not going to see very large scale research.  In this study, it was only 17 patients.  But the results were encouraging:  82% survived more than 2yrs on average.  Normally, this type of cancer will be fatal for about 35%, because it is often detected late.

For Onion Peelers,
Fourteen patients (82.3%) showed tumor response ..., and pathologic complete remission was confirmed in 93% of patients at neck dissection. Herpes virus was detected in injected and adjacent uninjected tumors at levels higher than the input dose, indicating viral replication....disease-specific survival was 82.4% at a median follow-up of 29 months (range, 19-40 months).

I like the idea of turning the tables on a virus that has been such a scourge to humanity, enlisting it's abilities in treating cancer.

Doc D

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