Navigation Links
Researchers block pathway to cancer cell replication

Research suggests that patients with leukemia sometimes relapse because standard chemotherapy fails to kill the self-renewing leukemia initiating cells, often referred to as cancer stem cells. In such cancers, the cells lie dormant for a time, only to later begin cloning, resulting in a return and metastasis of the disease.

One such type of cancer is called pediatric T cell acute lymphoblastic leukemia, or T-ALL, often found in children, who have few treatment options beyond chemotherapy.

A team of researchers led by Catriona H. M. Jamieson, MD, PhD, associate professor of medicine at the University of California, San Diego School of Medicine and Director of Stem Cell Research at UC San Diego Moores Cancer Center studied these cells in mouse models that had been transplanted with human leukemia cells. They discovered that the leukemia initiating cells which clone, or replicate, themselves most robustly activate the NOTCH1 pathway, usually in the context of a mutation.

Earlier studies showed that as many as half of patients with T-ALL have mutations in the NOTCH1 pathway an evolutionarily conserved developmental pathway used during differentiation of many cell and tissue types. The new study shows that when NOTCH1 activation was inhibited in animal models using a monoclonal antibody, the leukemia initiating cells did not survive. In addition, the antibody treatment significantly reduced a subset of these cancer stem cells (identified by the presence of specific markers, CD2 and CD7, on the cell surface.)

"We were able to substantially reduce the potential of these cancer stem cells to self-renew," said Jamieson. "So we're not just getting rid of cancerous cells: we're getting to the root of their resistance to treatment leukemic stem cells that lie dormant."

The study results suggest that such therapy would also be effective in other types of cancer stem cells, such as those that cause breast cancer, that also rely on NOTCH1 for self-renewal.

"Therapies based on monoclonal antibodies that inhibit NOTCH 1 are much more selective than using gamma-secretase inhibitors, which also block other essential cellular functions in addition to the NOTCH1 signaling pathway," said contributor A. Thomas Look, MD of Dana-Farber/Children Hospital Cancer Center in Boston. "We are excited about the promise of NOTCH1-specific antibodies to counter resistance to therapy in T-ALL and possibly additional types of cancer."

In investigating the role of NOTCH1 activation in cancer cell cloning, the researchers showed that leukemia initiating cells possess enhanced survival and self-renewal potential in specific blood-cell, or hematopoietic, niches: the microenvironment of the body in which the cells live and self-renew.

The scientists studied the molecular characterization of CD34+ cells a protein that shows expression in early hematopoietic cells and that facilitates cell migration from a dozen T-ALL patient samples.

They found that mutations in NOTCH1 and other genes capable of promoting the survival of cancer stem cells co-existed in the CD34+ niche. Mice transplanted with CD34-enriched NOTCH1 mutated T-ALL cells demonstrated significantly greater leukemic cloning potential than did mice without the NOTCH1 mutation. The mutated cells were uniquely susceptible to targeted inhibition with a human monoclonal antibody, according to the scientists.


Contact: Debra Kain
University of California - San Diego

Related medicine news :

1. NIH awards $20 million over 5 years to train next generation of global health researchers
2. Researchers develop a new cell and animal model of inflammatory breast cancer
3. Researchers uncover a viable way for colorectal cancer patients to overcome drug resistance
4. Researchers Find Gene Mutations That May Be a Key to Autism
5. Researchers find evidence of banned antibiotics in poultry products
6. NJ stroke researchers report advances in spatial neglect research at AAN Conference
7. Autism by the numbers: Yale researchers examine impact of new diagnostic criteria
8. Researchers Map Brain Regions Linked to Intelligence
9. Researchers ID Genes That May Determine Mental Illness
10. Researchers Develop Blood Test for Depression
11. University of Cincinnati researchers win $3.7M grant from US Department of Defense
Post Your Comments:
(Date:10/13/2017)... ... October 13, 2017 , ... The Visiting Nurse Association (VNA) ... a collection of specialty vendors and unique items from across the nation, this holiday-themed ... and wellness services offered by the VNA. The boutique will be open Saturday, ...
(Date:10/13/2017)... ... 13, 2017 , ... Global Healthcare Management’s 4th Annual Kids Fun Run brought ... This free event, sponsored by Global Healthcare Management’s CEO, Jon Letko, is aimed at ... towards children of all ages; it is a non-competitive, non-timed event, which is all ...
(Date:10/13/2017)... ... October 13, 2017 , ... Talented ... the lowdown on sciatica in a new episode of "Success Files," which is ... events and innovation and investigates each subject in-depth with passion and integrity. , ...
(Date:10/13/2017)... ... ... “The Journey: From the Mountains to the Mission Field”: the story of ... Philippines. “The Journey: From the Mountains to the Mission Field” is the creation of ... taught all ages and currently teaches a class of ladies at her church, which ...
(Date:10/12/2017)... ... October 12, 2017 , ... First ... compliance program management, will showcase a range of technology and learning solutions at ... (NCAL) Convention and Expo to be held October 14–18, 2017 at the Mandalay ...
Breaking Medicine News(10 mins):
(Date:9/12/2017)... YORK , Sept. 12, 2017   EcoVadis , the leading ... has published the first annual edition of its Global CSR Risk and ... companies evaluated by EcoVadis, based on Scorecard Ratings that analyzed nearly 800,000 ... ... Index ...
(Date:9/12/2017)... Sept. 12, 2017  ValGenesis Inc., the global ... is pleased to announce the appointment of Dr. ... its Board of Directors and Chairman of Advisory ... life science companies to manage their entire validation ... paper in this process. Furthermore, ValGenesis VLMS enables ...
(Date:9/9/2017)... 2017 Dealmed Medical Supplies, New ... equipment, supplies, drugs, vaccines, and specialty medical products and ... agreement to acquire Vantage Medical Supplies, a major distributor ... Holtsville, New York . ... emerging medical practices, will operate under the Dealmed name ...
Breaking Medicine Technology: