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

Loss of Specific MicroRNA Spurs Drug Resistance in Breast Cancer Cells

By BiotechDaily International staff writers
Posted on 17 May 2012
A study determined that development of resistance to the chemotherapeutic drug tamoxifen by breast tumors was due to the disappearance of a specific microRNA.

MicroRNAs are snippets of about 20 nucleotides that block gene expression by attaching to molecules of messenger RNA (mRNA) in a fashion that prevents them from transmitting the protein synthesizing instructions they had received from the DNA.

In the study, investigators at the German Cancer Research Center (Heidelberg, Germany) related genome-wide miRNA microarray analyses of breast tumors to the appearance in the tumors of resistance to tazmoxifen.

They reported in the April 16, 2012, online edition of the journal Oncogene that the microRNA miRNA-375 was among the top downregulated miRNAs in resistant cells. Reexpression of miR-375 was sufficient to resensitize tumor cells to tamoxifen and partly reversed the epithelial–mesenchymal transition (EMT), which is characteristic of tumor cells.

A combination of mRNA profiling, bioinformatics analysis, and experimental validation identified the protein metadherin (MTDH) as a direct target of miR-375. Metadherin is an oncogenic protein that is normally blocked by miR-375. The importance of MTDH was confirmed in experiments with tumor cells that lacked the MTDH gene. In these tumors, even in the absence of miR-375, no resistance to tamoxifen arose.

“The analysis of microRNAs in breast cancer has put us on the track of metadherin. We will possibly be able to specifically influence the cancer-promoting properties of this protein in the future,” said coauthor Dr. Stefan Wiemann, associate professor of molecular genome analysis at the German Cancer Research Center. “Resistances to drugs are the main reason why therapies fail and disease progresses in many cancers. We want to understand what goes on in the cells when this happens so we can develop better therapies in the future.”

Related Links:

German Cancer Research Center



comments powered by Disqus

Channels

Drug Discovery

view channel

Ibuprofen May Restore Immune Function in Older Individuals

New research suggests that macrophages from the lungs of old mice respond differently to infections than those of young mice, and ibuprofen given to the mice reversed these changes. New research using lab mice suggests that the solution to more youthful immune function might already be a common over-the-counter pain reliever.... Read more

Therapeutics

view channel
Image: Hair follicle (blue) being attacked by T cells (green) (Photo courtesy of Christiano Lab/Columbia University Medical Center).

Hair Restoration Method Clones Patients’ Cells to Grow New Hair Follicles

Researchers have developed of a new hair restoration approach that uses a patient’s cells to grow new hair follicles. In addition, the [US] Food and Drugs Administration (FDA) recently approved a new drug... Read more

Lab Technologies

view channel
Image: Leica Microsystems launches the inverted research microscope platform Leica DMi8 (Photo courtesy of Leica Microsystems).

New Inverted Microscope Designed to Readily Adapt to Changing Research Demands

A new inverted microscope for biotech and other life science laboratories was designed to readily accommodate modifications and upgrades to allow it to keep current with changing research demands and interests.... Read more

Business

view channel

Partnership Established to Decode Bowel Disease

23andMe (Mountain View, CA,USA), a personal genetics company, is collaborating with Pfizer, Inc. (New York, NY, USA), in which the companies will seek to enroll 10,000 people with inflammatory bowel disease (IBD) in a research project designed to explore the genetic factors associated with the onset, progression, severity,... Read more
 
Copyright © 2000-2014 Globetech Media. All rights reserved.