A new method for fighting ‘cold’ tumors

Source: www.eurekalert.org Author: news release University of Colorado Anschutz Medical Campus Not all cancerous tumors are created equal. Some tumors, known as "hot" tumors, show signs of inflammation, which means they are infiltrated with T cells working to fight the cancer. Those tumors are easier to treat, as immunotherapy drugs can then amp up the immune response. "Cold" tumors, on the other hand, have no T-cell infiltration, which means the immune system is not stepping in to help. With these tumors, immunotherapy is of little use. It's the latter type of tumor that researchers Michael Knitz and radiation oncologist and University of Colorado Cancer Center member Sana Karam, MD, PhD, address in new research published this week in the Journal for ImmunoTherapy of Cancer. Working with mouse models in Karam's specialty area of head and neck cancers, Knitz and Karam studied the role of T cells in tumor treatment. "What we found is that the cells that normally tell the T cell, 'Hey, here's a tumor -- come and attack it,' are being silenced," Karam says. She and her team found that regulatory T cells (Tregs), a specialized T cell type that suppresses immune response, are essentially telling the T cells to stop fighting the cancer. "Tregs normally serve as an important balance in a healthy immune system," Knitz says. "They prevent autoimmune disease and put the brakes on the T cells when needed. However, in many tumors, Tregs are too numerous or overly suppressive, bringing the T cell response [...]

Cancer ‘vaccine’ shown to be effective in small trial

Source: www.upi.com Author: Dennis Thompson, HealthDay News A new method of brewing a cancer vaccine inside a patient's tumor could harness the power of the immune system to destroy the disease, researchers report. Immune stimulants are injected directly into a tumor, which teaches the immune system to recognize and destroy all similar cancer cells throughout the body, said senior researcher Dr. Joshua Brody. He is director of the Lymphoma Immunotherapy Program at the Icahn School of Medicine at Mount Sinai in New York City. "We're injecting two immune stimulants right into one single tumor," Brody said. "We inject one tumor and we see all of the other tumors just melt away." Eight out of 11 lymphoma patients in a small, early clinical trial experienced partial or complete destruction of the tumor that received the initial injection, according to the report published April 8 in the journal Nature Medicine. The vaccine also halted overall cancer progression in six patients for three to 18 months, and caused significant regression or actual remission in three patients, the investigators found. The results were solid enough that the research team is expanding its next clinical trial to include lymphoma, breast, and head and neck cancer patients, Brody said. That trial started in March. Prior efforts at unleashing the immune system to fight cancer have focused on T-cells, which Brody calls the "soldiers" of the immune army because they directly attack harmful invaders in the body. Drugs called checkpoint inhibitors help T-cells identify cancer cells as [...]

Implant-based cancer vaccine is first to eliminate tumors in mice

Source: news.biocompare.com Authors: David J. Mooney et al. A cancer vaccine carried into the body on a carefully engineered, fingernail-sized implant is the first to successfully eliminate tumors in mammals, scientists report this week in the journal Science Translational Medicine. The new approach, pioneered by bioengineers and immunologists at Harvard University, uses plastic disks impregnated with tumor-specific antigens and implanted under the skin to reprogram the mammalian immune system to attack tumors. The new paper describes the use of such implants to eradicate melanoma tumors in mice. "This work shows the power of applying engineering approaches to immunology," says David J. Mooney, the Robert P. Pinkas Family Professor of Bioengineering in Harvard's School of Engineering and Applied Sciences and Wyss Institute for Biologically Inspired Engineering. "By marrying engineering and immunology through this collaboration with Glenn Dranoff at the Dana-Farber Cancer Institute, we've taken a major step toward the design of effective cancer vaccines." Most cancer cells easily skirt the immune system, which operates by recognizing and attacking invaders from outside the body. The approach developed by Mooney's group redirects the immune system to target tumors, and appears both more effective and less cumbersome than other cancer vaccines currently in clinical trials. Conventional cancer vaccinations remove immune cells from the body, reprogram them to attack malignant tissues, and return them to the body. However, more than 90 percent of reinjected cells have died before having any effect in experiments. The slender implants developed by Mooney's group are 8.5 millimeters in diameter [...]

2009-12-01T15:36:50-07:00December, 2009|Oral Cancer News|
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