Navigation Links
Researchers identify new pathway, enhancing tamoxifen to tame aggressive breast cancer
Date:4/23/2013

Tamoxifen is a time-honored breast cancer drug used to treat millions of women with early-stage and less-aggressive disease, and now a University of Rochester Medical Center team has shown how to exploit tamoxifen's secondary activities so that it might work on more aggressive breast cancer.

The research, published in the journal EMBO Molecular Medicine, is a promising development for women with basal-like breast cancer, sometimes known as triple-negative disease. This subtype has a poor prognosis because it is notoriously resistant to treatment. In fact, basal-like cancers lack the three most common breast cancer biomarkers the estrogen receptor, the progesterone receptor, and theHer2/neu receptor and without these receptors, the usual front-line treatments are not effective.

Until recently, tamoxifen was known primarily for its ability to block estrogen receptors on the outside of cancer cells. However, new studies have suggested that when tamoxifen is given in higher doses, it works through a second mechanism of action independent of the estrogen receptor. This second mechanism was the focus of the Rochester laboratory.

Led by doctoral student Hsing-Yu Chen and Mark Noble, Ph.D., professor of Biomedical Genetics at URMC, the team studied the molecular mechanism that allows basal-like breast cancer cells to escape the secondary effects of tamoxifen, and discovered that two proteins are critical in this escape. One protein, called c-Cbl, controls the levels of multiple receptors that are critical for cancer cell function. A second protein, Cdc42, can inhibit c-Cbl and is responsible for the tumor's underlying resistance.

The team also discovered that targeting Cdc42 and thus inhibiting the inhibitor - with an experimental drug compound known as ML141 restored c-Cbl's normal function. Through additional work in animal models and in human cell cultures, the team demonstrated that when ML141 is paired with tamoxifen, it enhances the ability of tamoxifen to induce cancer cell death and suppress the growth of new cancer cells. Neither drug alone had the same effect on basal-like breast cells.

Noble believes there is considerable value to targeting Cdc42, because elevated levels of the protein have been observed in multiple types of cancer. (In this context, scientists are also studying the potential for tamoxifen as a therapy for other cancers.)

The powerful ML141-tamoxifen drug combination looks like it has two more important features: It selectively targets cancer cells while sparing normal, healthy cells; and it appears to cripple cancer stem cells, the primitive cells responsible for initiating new tumors and for fueling the bulk of the tumor cell population.

"Our work is very exciting because our approach simultaneously addresses two of the most critical challenges in cancer research -- to increase the utility of existing therapies and to discover new vulnerabilities of cancer cells," said Noble, who also is a leader at UR's Stem Cell and Regenerative Medicine Institute. "Based on these discoveries, we are already pushing forward with new compounds and with new approaches that might make clinical translation of this discovery much more rapid than would occur with traditional drug-discovery approaches."


'/>"/>

Contact: Leslie Orr
leslie_orr@urmc.rochester.edu
University of Rochester Medical Center
Source:Eurekalert

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:
*Name:
*Comment:
*Email:
(Date:3/30/2021)... , ... March 29, 2021 , ... ... the 21st Century , A Virtual Workshop Presented by WCG FDAnews and Cerulean ... 4:30 pm EDT, https://wcg.swoogo.com/modern-sop-and-quality-systems , Are one’s SOPs written for the ...
(Date:3/30/2021)... ... March 29, 2021 , ... According to data released ... reproductive age (13-44) in need of publicly funded contraception live in counties impacted by ... Colorado’s 64 counties have lost some of their Title X resources. , The ...
(Date:3/30/2021)... ... March 29, 2021 , ... Health Literacy Innovations (HLI), a ... confusion due to low health literacy today announces a new partnership with the ... work with ACAP’s member Safety Net Health Plans, those that provide comprehensive health ...
(Date:3/30/2021)... ... ... Dr. Colin Campbell is proud to announce the 1 year anniversary in their new state ... internal medicine and is a primary care specialist who has been practicing for 23 years. ... keep South Jersey healthy one patient at a time. , “Over the past year, Dr. ...
(Date:3/30/2021)... ... March 30, 2021 , ... The COVID-19 ... and survivors; their families; and their caregivers. Crossroads4Hope is addressing the needs of ... emotional support system, MyGo2Support, which meets needs of people impacted by cancer, no ...
Breaking Medicine News(10 mins):
(Date:3/30/2021)... ... March 29, 2021 , ... The University of Texas Health Science Center ... San Antonio Multispecialty and Research Hospital, a destination center for research and treatment of ... In a nod to the COVID-19 pandemic, the ceremony was held virtually. , William ...
(Date:3/30/2021)... ... March 29, 2021 , ... Iora Health ... primary care, has partnered with Devoted Health , one of the fastest-growing ... across Maricopa County and provides seniors with the highest-quality care and experience possible, ...
(Date:3/30/2021)... CITY (PRWEB) , ... March 29, 2021 , ... ... has joined the Vaccine Credential Initiative (VCI), a group bringing together leading health ... record of vaccination status, based on open, interoperable standards. By joining the VCI ...
Breaking Medicine Technology: