Navigation Links
St. Jude Finds Link Between Cellular Defense Processes, Showing How Cancer Cells Survive
Date:12/19/2007

A mechanism in cells that kills germs and destroys cancer drugs and antibiotics is enlisted by a second mechanism that ingests germs from the environment, a finding that could improve treatments for cancer and infections

MEMPHIS, Tenn., Dec. 19 /PRNewswire-USNewswire/ -- St. Jude Children's Research Hospital investigators have discovered that immune system cells that engulf and destroy germs in the body enlist help for this task from a common housekeeping mechanism that most cells use to keep their interiors healthy, a finding that is likely to help researchers understand how the body defends itself against infections and how cancer cells can resist chemotherapy drugs before they have a chance to work.

The discovery of this link between the two mechanisms --- phagocytosis (engulfing germs) and autophagy (housekeeping) --- suggests that a common mechanism that triggers both processes individually also links them together using a common set of signals. The processes of phagocytosis and autophagy enclose various cellular structures or germs within a sac that fuses with a bag of digestive enzymes called the lysosome. The lysosome then releases the digestive enzymes into the sac and the enzymes degrade its contents. A report on the discovery appears in the Dec. 20 issue of the journal "Nature."

The St. Jude team discovered that TLR, a protein on the surface of cells that phagocytize germs, is the link between this "outside job" of germ engulfment and the housekeeping "inside jobs" done by autophagy, such as destroying germs that have forced their way into the cell and breaking down defective molecules to obtain nutrients during times of stress. Specifically, TLR recruits special proteins that orchestrate autophagy and uses them to supervise phagocytosis and the formation of the digestive sac called the phagosome.

"Our findings strongly suggest that TLR recruits parts of the autophagy machinery to enable the phagosome to fully develop and fuse with the lysosome even if autophagy itself doesn't occur simultaneously," said Douglas Green, Ph.D., chair of the St. Jude Department of Immunology and senior author of the report.

"Now that we discovered that phagocytosis uses some of the same biochemical signals as autophagy does, we can use that information to solve the mystery of how autophagy works," said Miguel Sanjuan, Ph.D., a staff scientist in Green's laboratory and first author of the report.

Other authors of this paper include Christopher P. Dillon, Stephen W. G. Tait, Simon Moshiach, Samuel Connell and Sebo Withoff (St. Jude); Masaaki Komatsu and Keiji Tanaka (Tokyo Metropolitan Institute of Medical Science, Japan); Frank Dorsey and John L. Cleveland (The Scripps Research Institute, Jupiter, Florida).

This work was supported by the National Institutes of Health and ALSAC.

St. Jude Children's Research Hospital

St. Jude Children's Research Hospital is internationally recognized for its pioneering work in finding cures and saving children with cancer and other catastrophic diseases. Founded by late entertainer Danny Thomas and based in Memphis, Tenn., St. Jude freely shares its discoveries with scientific and medical communities around the world. No family ever pays for treatments not covered by insurance, and families without insurance are never asked to pay. St. Jude is financially supported by ALSAC, its fundraising organization. For more information, please visit http://www.stjude.org.


'/>"/>
SOURCE St. Jude Children's Research Hospital
Copyright©2007 PR Newswire.
All rights reserved

Related medicine news :

1. Penn study finds pro-death proteins required to regulate healthy immune function
2. MRI finds breast cancer before it becomes dangerous
3. RAND finds cases of undiagnosed diabetes drop sharply
4. Children of depressed moms do better when dad is involved, SLU researcher finds
5. Ability to cope with stress can increase good cholesterol in older white men, study finds
6. Pitt study finds inequality in tobacco advertising
7. Study finds some kids are being misdiagnosed with asthma
8. Investigational Agent Targeting Metabotropic Glutamate 2/3 Receptors Demonstrates Antipsychotic Activity in Humans, Study in Nature Medicine Finds
9. Parents perceptions can hamper kids asthma care, study finds
10. Study finds primary care depression treatment often does not follow quality guidelines
11. Study of Studies Finds No Risk to Children From Phthalates in Toys
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:2/5/2016)... ... February 05, 2016 , ... ... to funding innovative lymphoma research and serving the lymphoma community through a comprehensive ... once again host, Swirl, A Wine Tasting Event at the La Gorce Country ...
(Date:2/5/2016)... ... ... Give To Cure today announced that it is working with ... campaign that is crowdfunding clinical trials to help find cures faster for Alzheimer’s Disease. ... device. In 2015 alone, Venmo processed $7.5 billion in transactions among users. , Give ...
(Date:2/5/2016)... ... 05, 2016 , ... Stuart Bentkover, MD, FACS is thrilled to ... the most effective tattoo removal today, Dr. Bentkover is the only doctor in Central ... the PicoSure has been approved by the Food and Drug Administration (FDA) as a ...
(Date:2/5/2016)... ... February 05, 2016 , ... California Mobile Kitchens , ... of their latest mobile kitchen model, featuring customizable stainless steel interiors and a ... kitchens for use anywhere in the U.S. Many of their units can be ...
(Date:2/5/2016)... ... 2016 , ... Susan Polk Health Insurance Company recently released a ... see in 2016. To view the report, see below, or visit Susan Polk's ... Luis Obispo seniors who rely on Medicare health insurance and whose monthly income includes ...
Breaking Medicine News(10 mins):
(Date:2/5/2016)... -- France , Germany , ... Israel ). It includes a 10-year epidemiology forecast for ... by age and sex in these markets. GD epidemiology report is written ... high quality, transparent and market-driven, providing expert analysis of disease trends in ... , Italy , Spain , ...
(Date:2/4/2016)... -- The Senior Care Pharmacy Coalition (SCPC) today commended ... Jason Chaffetz (R-UT) and Ranking Member Elijah ... "Developments in the Prescription Drug Market," to examine ... abusive pharmacy benefit manager (PBM) pricing practices. ... Elijah Cummings (D-MD) are diligent, serious lawmakers committed ...
(Date:2/4/2016)... Wegener Polyangiitis - Pipeline Review, H2 ... Polyangiitis - Pipeline Review, H2 2015, provides an ... This report provides comprehensive information on the therapeutic ... at various stages, therapeutics assessment by drug target, ... and molecule type, along with latest updates, and ...
Breaking Medicine Technology: