The RhoA pathway mediates MMP-2 and MMP-9-independent invasive behavior in a triple-negative breast cancer cell line
Breast cancer is a heterogeneous disease that varies in its biology and response to therapy. A foremost threat to patients is tumor invasion and metastasis, with the greatest risk among patients diagnosed with triple‐negative and/or basal‐like breast cancers. A greater understanding of the molecular...
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Published in | Journal of cellular biochemistry Vol. 114; no. 6; pp. 1385 - 1394 |
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Main Authors | , , , , , , |
Format | Journal Article |
Language | English |
Published |
Hoboken
Wiley Subscription Services, Inc., A Wiley Company
01.06.2013
Wiley Subscription Services, Inc |
Subjects | |
Online Access | Get full text |
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Summary: | Breast cancer is a heterogeneous disease that varies in its biology and response to therapy. A foremost threat to patients is tumor invasion and metastasis, with the greatest risk among patients diagnosed with triple‐negative and/or basal‐like breast cancers. A greater understanding of the molecular mechanisms underlying cancer cell spreading is needed as 90% of cancer‐associated deaths result from metastasis. We previously demonstrated that the Tamoxifen‐selected, MCF‐7 derivative, TMX2‐28, lacks expression of estrogen receptor α (ERα) and is highly invasive, yet maintains an epithelial morphology. The present study was designed to further characterize TMX2‐28 cells and elucidate their invasion mechanism. We found that TMX2‐28 cells do not express human epidermal growth factor receptor 2 (HER2) and progesterone receptor (PR), in addition to lacking ERα, making the cells triple‐negative. We then determined that TMX2‐28 cells lack expression of active matrix metalloproteinases (MMPs)‐1, MMP‐2, MMP‐9, and other genes involved in epithelial–mesenchymal transition (EMT) suggesting that TMX2‐28 may not utilize mesenchymal invasion. In contrast, TMX2‐28 cells have high expression of Ras Homolog Gene Family Member, A (RhoA), a protein known to play a critical role in amoeboid invasion. Blocking RhoA activity with the RhoA pathway specific inhibitor H‐1152, or a RhoA specific siRNA, resulted in inhibition of invasive behavior. Collectively, these results suggest that TMX2‐28 breast cancer cells exploit a RhoA‐dependent, proteolytic‐independent invasion mechanism. Targeting the RhoA pathway in triple‐negative, basal‐like breast cancers that have a proteolytic‐independent invasion mechanism may provide therapeutic strategies for the treatment of patients with increased risk of metastasis. J. Cell. Biochem. 114: 1385–1394, 2013. © 2013 Wiley Periodicals, Inc. |
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Bibliography: | ark:/67375/WNG-9XCLKZ7P-D ArticleID:JCB24480 Rays of Hope Foundation Predoctoral Traineeship Award, DoD Breast Cancer Research Program - No. W81XWH-09-1-0345 The authors declare that they have no conflict of interest or competing financial interests. istex:C823ECC4B55FFDFD0BCDDDAE04F838F129D904DF ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0730-2312 1097-4644 |
DOI: | 10.1002/jcb.24480 |