Protein Found in Triple-Negative Breast Cancer May Lead to New Therapies

July 14, 2016

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Take-Home Message:

Researchers have discovered a protein involved in triple-negative breast cancer that may lead to development of new medications.

 

GSTP1 Is a Driver of Triple-Negative Breast Cancer Cell Metabolism and Pathogenicity

Authors: Louie et. al.
Source: Cell Chem Biol, 10.1016/j.chembiol.2016.03.017
www.ncbi.nlm.nih.gov/pubmed/27185638

There are several types of breast cancers, each of which depends on the category of cells that are growing and the various proteins involved in the metabolism of those cancer cells. One such type of breast cancer, triple-negative breast cancer (TNBC), infers a more aggressive cancer and poorer prognosis. TNBC does not respond to typical breast cancer therapies. Unfortunately, there are few medications that can be used to treat TNBC. This study looked at a variety of different proteins that could possibly interfere with the TNBC cells’ ability to grow and reproduce. One such protein, known as GSTP1, was found to affect the metabolism of TNBC cells in a way that could potentially be blocked by a medication.  While several GSTP1-blocking drugs have been studied, they have not been studied specifically for breast cancer.

The researchers tagged certain amino acids (the building blocks of proteins) in TNBC cells with markers that could be identified utilizing specialized procedures, such as immunohistochemistry. They found that GSPT1 levels were very high in these cells. Through various specialized laboratory procedures the researchers discovered that GSTP1 is not involved with any non-TNBC breast cancer cells, suggesting that GSTP1 is specific to TNBC cells. The investigators developed a substance (LAS17) that impairs GSTP1’s function. When GSTP1 was inactivated, the TNBC cells were not able to perform the essential cell function of using glucose as well. GSPT1 inactivation also resulted in increased levels of another protein (AMPK), which made the TNBC cells less able to grow and multiply. The findings of this study are important because it has highlighted a specific protein that may be targeted by medications in the future to help fight triple-negative breast cancer.