Drug/radiation combo may help shrink established tumors

August 25, 2008

Researchers may be closer to understanding why anti-cancer drugs such as Ipilimumab, which boost the tumor-killing power of immune cells, haven't fared well in clinical trials. The new study, which describes a way to enhance the ability of these drugs to shrink well-established tumors, will be published online on August 25th in the Journal of Experimental Medicine.

The immune system's tumor-fighting T cells work best when maximally activated. Scientists have achieved this by blocking molecules that dampen the cells' activation, or by removing a population of regulatory T cells that block the killing ability of tumor-specific T cells. But neither approach has worked well in patients with established tumors.

Combining these two approaches in mice, the new study shows, caused small tumors to shrink but had no effect on large tumors. This finding suggested that some quality of large tumors makes them resistant to T cell killing.

Indeed, the blood vessels around large tumors lacked proteins required for killer T cells to crawl out of the circulation and into the tumor. Combining the T cell-boosting treatment with radiation therapy--which has been shown to increase the expression of these vessel proteins--was effective in shrinking large tumors. It remains to be seen whether combining radiation therapy with T cell-boosting drugs will be effective in humans.
-end-


Journal of Experimental Medicine

Related Immune Cells Articles from Brightsurf:

Gut immune cells may help send MS into remission
An international research team led by UCSF scientists has shown, for the first time, that gut immune cells travel to the brain during multiple sclerosis (MS) flare-ups in patients.

Immune cells sculpt circuits in the brain
Brain immune cells, called microglia, protect the brain from infection and inflammation.

How tumor cells evade the immune defense
Scientists are increasingly trying to use the body's own immune system to fight cancer.

Breast cancer cells can reprogram immune cells to assist in metastasis
Johns Hopkins Kimmel Cancer Center investigators report they have uncovered a new mechanism by which invasive breast cancer cells evade the immune system to metastasize, or spread, to other areas of the body.

Breast cancer cells turn killer immune cells into allies
Researchers at Johns Hopkins University School of Medicine have discovered that breast cancer cells can alter the function of immune cells known as Natural killer (NK) cells so that instead of killing the cancer cells, they facilitate their spread to other parts of the body.

Engineered immune cells recognize, attack human and mouse solid-tumor cancer cells
CAR-T therapy has been used successfully in patients with blood cancers such as lymphoma and leukemia.

Mapping immune cells in brain tumors
It is not always possible to completely remove malignant brain tumors by surgery so that further treatment is necessary.

Nutrient deficiency in tumor cells attracts cells that suppress the immune system
A study led by IDIBELL researchers and published this week in the American journal PNAS shows that, by depriving tumor cells of glucose, they release a large number of signaling molecules.

Experience matters for immune cells
The discovery that immune T cells have a spectrum of responsiveness could shed light on how our immune system responds to infections and cancer, and what goes wrong in immune diseases.

Immune cells against Alzheimer's?
German researchers have developed a novel, experimental approach against Alzheimer's.

Read More: Immune Cells News and Immune Cells Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.