Group develops method of killing cancer cells with antibodies and light

November 7, 2011 by Bob Yirka, Medical Xpress report

(Medical Xpress) -- Traditionally, there are three major ways to combat cancer in people: surgical removal, radiation therapy and chemotherapy. And while all three have been proven to be effective in treating some types of cancer, all three also have unpleasant side effects. It’s for this reason that researchers continue to try to find other ways to kill cancer cells. Now, in a paper published in Nature Medicine, a team from the National Cancer Institute in the United States, says that it has developed a type of photoimmunotherapy that combines a light-sensitive dye that has a special chemical in it and antibodies to target and kill cancer cells when light is shined on them.

Photoimmunotherapy has been tried before, but not in this way, in previous research such antibodies were not nearly so target specific, meaning they tended to kill other cells as well. In this latest research, the team was able to use tumor specific antibodies that would attach themselves to the , but would remain dormant. It was only when the same cancer cells were also exposed to a chemical called IR700 and then exposed to light that the antibodies went to work killing the cancer cells.

In their lab studies, the team inserted a type of skin cancer into the skin on the back of a mouse; when given the drug and then exposed to light, the research team found that the size of the tumor in the mouse was significantly reduced compared to control mice. They also found that other cells around the tumor were unaffected and that there didn’t appear to be any toxic reactions to the treatment.

It’s not yet known if the procedure would work in humans, but further research is likely to be done in a lot of areas, likely including other types of animals before tests can be conducted with human volunteers. Also, research is continuing to see if it might be possible to use to deliver other sorts of cancer killing agents, such as radiation.

If such types of photoimmunotherapy prove workable, millions of people the world over might be spared the pain of surgery and/or the harmful side effects of radiation and .

Explore further: Pancreas betrayed by 'double agent'

More information: Cancer cell–selective in vivo near infrared photoimmunotherapy targeting specific membrane molecules, Nature Medicine (2011) doi:10.1038/nm.2554

Three major modes of cancer therapy (surgery, radiation and chemotherapy) are the mainstay of modern oncologic therapy. To minimize the side effects of these therapies, molecular-targeted cancer therapies, including armed antibody therapy, have been developed with limited success. In this study, we have developed a new type of molecular-targeted cancer therapy, photoimmunotherapy (PIT), that uses a target-specific photosensitizer based on a near-infrared (NIR) phthalocyanine dye, IR700, conjugated to monoclonal antibodies (mAbs) targeting epidermal growth factor receptors. Cell death was induced immediately after irradiating mAb-IR700–bound target cells with NIR light. We observed in vivo tumor shrinkage after irradiation with NIR light in target cells expressing the epidermal growth factor receptor. The mAb-IR700 conjugates were most effective when bound to the cell membrane and produced no phototoxicity when not bound, suggesting a different mechanism for PIT as compared to conventional photodynamic therapies. Target-selective PIT enables treatment of cancer based on mAb binding to the cell membrane.

Related Stories

Pancreas betrayed by 'double agent'

May 30, 2011
(Medical Xpress) -- Stellate cells, a type of cell in the pancreas which normally helps the body respond to damage or disease of the pancreas, can act as a double agent when it comes to cancer.

Stem cells, potential source of cancer-fighting T cells

September 20, 2011
Adult stem cells from mice converted to antigen-specific T cells -- the immune cells that fight cancer tumor cells -- show promise in cancer immunotherapy and may lead to a simpler, more efficient way to use the body's immune ...

Recommended for you

Boosting cancer therapy with cross-dressed immune cells

January 22, 2018
Researchers at EPFL have created artificial molecules that can help the immune system to recognize and attack cancer tumors. The study is published in Nature Methods.

Cancer patients who tell their life story find more peace, less depression

January 22, 2018
Fifteen years ago, University of Wisconsin–Madison researcher Meg Wise began interviewing cancer patients nearing the end of life about how they were living with their diagnosis. She was surprised to find that many asked ...

Workouts may boost life span after breast cancer

January 22, 2018
(HealthDay)—Longer survival after breast cancer may be as simple as staying fit, new research shows.

Single blood test screens for eight cancer types

January 18, 2018
Johns Hopkins Kimmel Cancer Center researchers developed a single blood test that screens for eight common cancer types and helps identify the location of the cancer.

Researchers find a way to 'starve' cancer

January 18, 2018
Researchers at Vanderbilt University Medical Center (VUMC) have demonstrated for the first time that it is possible to starve a tumor and stop its growth with a newly discovered small compound that blocks uptake of the vital ...

How cancer metastasis happens: Researchers reveal a key mechanism

January 18, 2018
Cancer metastasis, the migration of cells from a primary tumor to form distant tumors in the body, can be triggered by a chronic leakage of DNA within tumor cells, according to a team led by Weill Cornell Medicine and Memorial ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

not rated yet Nov 07, 2011
I love this story. Wonder if just visible light is the only activator however. How nice if terahertz radiation as opposed to visible light radiation could also be used. Reason being is that terahertz radiation could penetrate deeper than visible light with probably no damage to tissue...hey the Transport Security boys and girls use it to gawk at all the women and men airline passenger's 'soft parts' disrespectfully so this has the USDA mark of 'approval'. Then all kidding aside, two terahertz laser beams could be used to intersect in three dimensional space inside the patient's body at the precise intended treatment location; uniting with the antibodies there to destroy the cancers without surgery.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.