Features | Partner Sites | Information | LinkXpress
Sign In
GLOBETECH PUBLISHING
JIB
BioConferenceLive

Brain Cancer Patient’s Own Immune Cells May Suppress Viral Therapy

By BiotechDaily International staff writers
Posted on 03 Dec 2012
Clinicians are now employing cancer-killing viruses to treat some patients with deadly, fast-growing brain tumors. Clinical trials have demonstrated that these therapeutic viruses are safe but less effective than once thought.

A new study led by researchers at the Ohio State University Comprehensive Cancer Center-Arthur G. James Cancer Hospital and Richard J. Solove Research Institute (OSUCCC-James; Columbus, USA) revealed that the reason for this is partly caused by the patient’s own immune system, which quickly works to eliminate the anticancer virus.

The findings, published November 25, 2012, in the journal Nature Medicine, demonstrate that the body responds to the anticancer virus the same as it does to an infection. Within hours, specialized immune cells called natural killer (NK) cells move in to eliminate the therapeutic virus in the brain.

The researchers discovered that the NK cells attack the viruses when they express specific molecules on their surface called NKp30 and NKp46. “These receptor molecules enable the NK cells to recognize and destroy the anticancer viruses before the viruses can destroy the tumor,” stated cosenior author Dr. Michael A. Caligiuri, director of Ohio State’s Comprehensive Cancer Center and CEO of the James Cancer Hospital and Solove Research Institute, and a senior author of the study. “When we blocked those receptors, the virus has more time to work, and mice with these brain tumors live longer. The next step is to block these molecules on NK cells in glioblastoma patients and see if we can improve their outcome,” said Dr. Caligiuri.

This study of cancer-cell-killing (oncolytic) viruses exemplifies the benefits of translational research, in which a problem observed during clinical trials is studied in the laboratory to devise a solution. “In this case, clinical trials of oncolytic viruses proved safe for use in the brain, but we noticed substantial numbers of immune cells in brain tumors after treatment,” remarked senior author and neurosurgeon Dr. E. Antonio Chiocca, who was professor and chair of neurological surgery while at Ohio State University. “To understand this process, we went back to the laboratory and showed that NK cells rapidly infiltrate tumors in mice that have been treated with the therapeutic virus. These NK cells also signal other inflammatory cells to come in and destroy the cancer-killing virus in the tumor.”

The study used an oncolytic herpes simplex virus, human glioblastoma tumor tissue and mouse models, one of which hosted both human glioblastoma cells and human NK cells. Key technical findings include: NK cells in tumors triggered other immune cells (i.e., microglia and macrophages) that have both antiviral and anticancer characteristics; replication of the therapeutic virus in tumor cells in an animal model quickly drew subsets of NK cells to the tumor site; depletion of NK cells improves the survival of tumor-bearing mice treated with the therapeutic virus; NK cells that kill virus-infected tumor cells express the NKp30 and NKp46 receptors molecules that recognize the virus.

“Once we identify the molecules on glioblastoma cells that these NK cell receptors bind with, we might be able to use them to identify patients who will be sensitive to this therapy,” Dr. Caligiuri concluded.

Related Links:

Ohio State University Comprehensive Cancer Center-Arthur G. James Cancer Hospital and Richard J. Solove Research Institute




comments powered by Disqus

Channels

Genomics/Proteomics

view channel
Image: In the liver tissue of obese animals with type II diabetes, unhealthy, fat-filled cells are prolific (small white cells, panel A). After chronic treatment through FGF1 injections, the liver cells successfully lose fat and absorb sugar from the bloodstream (small purple cells, panel B) and more closely resemble cells of normal, non-diabetic animals (Photo courtesy of the Salk Institute for Biological Studies).

Fibroblast Growth Factor 1 Treatment Restores Glucose Control in Mouse Diabetes Model

A "vaccine" based on the metabolic regulator fibroblast growth factor 1 (FGF1) removed the insulin resistance that characterizes type II diabetes and restored the body's natural ability to manage its glucose... Read more

Drug Discovery

view channel
Image: Molecular rendering of the crystal structure of parkin (Photo courtesy of Wikimedia Commons).

Cinnamon Feeding Blocks Development of Parkinson's Disease in Mouse Model

A team of neurological researchers has identified a molecular mechanism by which cinnamon acts to protect neurons from damage caused by Parkinson's disease (PD) in a mouse model of the syndrome.... Read more

Lab Technologies

view channel

Precise Ion Irradiation Dosing Method Developed for Cancer Therapy

Scientists are employing nuclear physics principles to provide more effective approaches to radiotherapy treatment for cancer patients. Radiation therapy using heavy ions is best suitable for cancer patients with tumors that are difficult to access, such as in the brain. These particles scarcely damage the penetrated... Read more

Business

view channel

Cancer Immunotherapy Sector Predicted to Surge to USD 9 Billion Across Major Pharma Through 2022

The immunotherapy market will experience substantial growth through 2022, increasing from USD 1.1 billion in 2012 to nearly USD 9 billion in 2022 (corresponding to 23.8% annual growth) in the United Kingdom, United States, France, Germany, Italy, Spain, and Japan, according to recent market research. This notable growth... Read more
 
Copyright © 2000-2014 Globetech Media. All rights reserved.