Navigation Links
Immune system changes may drive aggressiveness of recurrent tumors
Date:12/27/2012

PHILADELPHIA Nearly half of the 700,000 cancer patients who undergo surgical removal of a primary tumor each year suffer a recurrence of their disease at some point, and many of those patients will eventually die from their disease. The traditional view of recurrent tumors is that they are resistant to therapy because they've acquired additional genetic mutations that make them more aggressive and impervious to drugs. Now, however, researchers at the Perelman School of Medicine at the University of Pennsylvania show in an animal model that the enhanced aggressiveness of recurrent tumors may be due to changes in the body's immune response. The findings are published this week in the Proceedings of the National Academy of Sciences.

"Typically when a patient has a tumor recurrence, their oncologist treats them, much like they treated them for the primary tumor with drugs aimed at the tumor cells themselves. But we've found that it might be better to attack the tumor cells and knock down the bad immune cells that are protecting the tumor," says senior study author Sunil Singhal, MD, assistant professor of Surgery and director, Thoracic Surgery Research Laboratory at the Perelman School of Medicine.

To assess the impact of anti-cancer vaccines on primary and recurrent tumors, the researchers immunized mice that had a primary or a recurrent tumor in their flank. Although both groups of animals developed an immune response to the vaccine, only the primary-tumor animals showed tumor shrinkage in response to the vaccine. The recurrent tumors appeared unaffected by the vaccine response. Moreover, this pattern held for several different vaccines.

Despite the prevailing models of tumor recurrence which emphasize genetic changes in the tumor cells themselves Singhal and colleagues could not find substantial genetic or behavior differences in the recurrent versus primary tumors that might account for the pattern of response.

By contrast, when the team looked at the types of immune cells in and around the tumor, Singhal's team saw a big difference. The recurrent-tumor mice had a large increase in the number of regulatory T cells, compared with primary-tumor animals. That could be important, says Singhal, because T regulatory cells are responsible for holding other immune cells in check and blocking immune responses.

Additionally, macrophages that protect the tumor cells from immune system also increased in number and activity in the recurrent-tumor animals.

Remarkably, when the researchers treated recurrent-tumor animals with drugs that block macrophage activity, tumor growth slowed significantly. However, the same drugs had no effect on primary-tumor animals.

Singhal says it is not clear exactly what triggers the immune system changes, but whatever it is appears to happen at the time of surgery. His group has already started looking for alterations in signaling molecules.

In the meantime, though, he notes that there are newly approved drugs and experimental agents that block regulatory T cells. Given his team's new results, he thinks testing these agents in patients with recurrent disease in combination with drugs that attack the tumor cells themselves could be an important advance for patients.

"We could impact the outcomes of as many as 250,000 patients a year, if this strategy works," he said.


'/>"/>

Contact: Jessica Mikulski
jessica.mikulski@uphs.upenn.edu
215-349-8369
University of Pennsylvania School of Medicine
Source:Eurekalert

Related medicine news :

1. Bioforce AG Announces Doctors Comments Showing Efficacy of Echinaforce for Immune Support Now On You Tube
2. Auto-immune disease: The viral route is confirmed
3. The role of the innate immune cells in the development of type 1 diabetes
4. Cancer cells co-opt immune response to escape destruction
5. Immune System May Not Weaken With Age: Study
6. Blood levels of immune protein predict risk in Hodgkin disease
7. UT MD Anderson, GlaxoSmithKline to collaborate on new approach to cancer immune therapy
8. Immune system kill switch could be target for chemotherapy and infection recovery
9. Cocktail boosts immune cells in fighting cancer
10. Improving chemotherapy effectiveness by acting on the immune system
11. Patients own immune cells may blunt viral therapy for brain cancer
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:5/24/2017)... ... 24, 2017 , ... Altec Products, Inc., a leader in enterprise ... one-day technology conference in San Diego, CA. , At nVerge 2017, Altec will ... utilize and enhance their Sage ERP solutions by providing improved visibility and control to ...
(Date:5/24/2017)... ... ... Dr. Manju R. Kejriwal, a leading Ohio dentist, is now welcoming new ... Dr. Kejriwal understands the emotional and financial toll traditional orthodontics can take on patients’ ... longer need to feel the esthetic effects of wires and brackets when they can ...
(Date:5/24/2017)... ... 24, 2017 , ... Myers Jackson is well known for auctioning homes that ... homes anywhere on the planet. The luxury home market is alive and well and ... A quick search of “11 Spyglass Hill Auction will enlighten you on the dynamics ...
(Date:5/24/2017)... ... May 24, 2017 , ... Medic CE , a ... Truth about Pediatric Septic Shock” hosted by the Journal of Emergency Medical Services (JEMS). ... Eastern time, will be presented by Captain Rommie Duckworth, LP, a career fire captain ...
(Date:5/24/2017)... , ... May 24, 2017 , ... ... is offering holistic pediatric dentistry options for its patients on Long Island, New ... patient’s entire physical well being, and is one of the biggest trends in ...
Breaking Medicine News(10 mins):
(Date:5/8/2017)... -- MACRA replaces the outdated sustainable growth rate ... Black Book Research crowdsource-surveyed 8,845 physician practices from February ... for MIPS Compliance Technology is Booming ... or more clinicians seek to buy Merit-Based Incentive Payment ... of the changes, the hunt is on for the ...
(Date:5/6/2017)...  May is Stroke Awareness Month and Omron Healthcare ... methods to prevent a stroke: monitor and manage your ... and Prevention, undetected and uncontrolled hypertension is a leading ... leader in personal heart health technology, recently evolved its ... and stroke and is advancing a national public education ...
(Date:5/4/2017)... 4, 2017  A recent study published in ... Ultraviolet-C light as a means of disinfection anesthesia ... reduce bioburden on anesthesia workstations. In the study, ... complex medical equipment surfaces contaminated with three (3) ... "This study further validates the body of literature ...
Breaking Medicine Technology: