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Nano treatments to target cancer cells

Published: 10/03/2009 - PDF Version (78 KB)

Cancer research UK scientists have for the first time developed a treatment that transports 'tumour busting' genes selectively to cancer cells, according to a study published online in Cancer Research.

Using nanotechnology, the researchers were able to package anti-cancer genes in very small particles that directed the treatment selectively to tumours in mice so that it was only taken up by cancer cells, leaving healthy cells unharmed.

Once taken up by cancer cells, the genes enclosed in the nanoparticles force the cell to produce proteins that can kill the cancer.

In this study the cells were forced to make a protein which was then visible in whole-body scans of the mice revealing that healthy cells were not affected by the treatment.

Previous studies showed that the type of gene therapy used in this study can shrink tumours and even cure around 80 per cent of the mice given the treatment.

This type of technology is particularly relevant for people with cancers that are inoperable because they are close to vital organs, like the brain or lungs. These cancers are often associated with poor survival.

Now scientists have found a particle that can be used to selectively target cancer cells, they hope nanotechnology can be extended to treat cancer that has spread.

Study author Cancer Research UK's Dr Andreas Schatzlein, based at the School of Pharmacy in London, said: "Gene therapy has a great potential to create safe and effective cancer treatments but getting the genes into cancer cells remains one of the big challenges in this area. This is the first time that nanoparticles have been shown to target tumours in such a selective way, and this is an exciting step forward in the field.

"Once inside the cell, the gene enclosed in the particle recognises the cancerous environment and switches on. The result is toxic, but only to the offending cells, leaving healthy tissue unaffected. We hope this therapy will be used to treat cancer patients in clinical trials in a couple of years."

Traditional chemotherapy indiscriminately kills cells in the affected area of the body, which can cause side effects like fatigue, hair loss or nausea. It is hoped that gene therapy will have fewer associated side effects by targeting cancer cells.

Dr Lesley Walker, Cancer Research UK's director of cancer information, said:
"These results are encouraging, and we look forward to seeing if this method can be used to treat cancer in people. Gene therapy is an exciting area of research, but targeting genetic changes to cancer cells has been a major challenge. This is the first time a solution has been proposed, so it's exciting news."

Article reference: Cancer-specific transgene expression mediated by systemic injection of nanoparticles. Chisholm et al. Cancer Research. March 2009.

Comments

10/04/2009 06:54:51
Comment by aliyaba

when drug media carry the antigen to cancer cell , i suppose that there will be more side effect speciall if we use the media like gold ?!

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10/04/2009 07:30:27
Comment by Dr. A. Naser Nourallah M.D: Syrian American Cancer Center

It is Interesting -- but why does the cancer cell "take up" the nanoparticle :That's the whole key?.

Researchers from the University of California, San Francisco and Georgia Institute of Technology have found a new way to kill cancer cells. Building on their previous work that used gold nanoparticles to detect cancer, they now are heating the particles and using them as agents to destroy malignant cells.

the paragraph below explains how they target cancer cells
Particle Sciences, Inc.
Drug Development Services Nanosystems, Formulation, Analytic
www.particlesciences.com

The researchers are a father and son, working together on opposite coasts. Their study findings are reported in the on-line edition of the journal Cancer Letters, found at Sciencedirect.com (quicksearch: El-Sayed nanoparticles).

"In an earlier study we showed how gold nanoparticles could be bound to malignant cells, making cancer detection easier. Now we have examined how the particles' ability to absorb light helps kill those cancer cells," said principal author Ivan El-Sayed, MD, assistant professor of otolaryngology at UCSF Medical Center.

Ivan conducted the study with his father, Mostafa El-Sayed, PhD, director of the Laser Dynamics Laboratory and chemistry professor at Georgia Tech.

We know that many cancer cells have a protein, known as epidermal growth factor receptor (EGFR), all over their surface, while healthy cells typically do not express the protein as strongly. By conjugating, or binding, the gold nanoparticles to an antibody for EGFR, suitably named anti-EGFR, the researchers were able to get the nanoparticles to specifically attach themselves to the cancer cells.

There's a number of drugs in trials (and one in commercial use for leukemia) in which a toxin is attached to a monoclonal antibody, thus delivering it to the cancer cell.

The fact that a gold nanoparticle was attached in this trial really doesn't change the basic reaction -- antibody binds to cell receptor, antibody is internalized, compound attached to antibody is injected into cell.

We already have targeted treatment whether EGFR: Tyrosine Kinase inhibitors or Monoclonal antibodies attached to to cancer cells(without gold nanoparticles). However, the breakthrough news was only in few malignacies: Glevic and CML or GIST,and few others.
Generally speaking,The outcome of treatment other malignacies was not so striking in comparision to Gleevic in CML or GIST . I mean there are undeniable advances in Oncology, yet, we have long way to go and I don't know if "gold nano" will make any difference.

Dean Koontz has a novel out about a crazed scientist who injects folks with nanoparticles to accomplish a number of outcomes--his personal human trials, but that's fiction. Only time will tell. For some reason, as luck may have it, I've had contact with a number of biomedical startups over the years as a consult and have seen some strange approaches in progress with surprisingly positive results. Some in phase-three clinical trials now. Who knows?