Diagnosis of metastatic breast cancer is associated with a very poor prognosis. New therapeutic targets are urgently needed, but their development is hampered by a lack of understanding of the mechanisms leading to tumor metastasis. Exemplifying this is the fact that the approximately 30% of all breast cancers overexpressing the receptor tyrosine kinase ErbB-2 are characterized by high metastatic potential and poor prognosis, but the signaling events downstream of ErbB-2 that drive cancer cell invasion and metastasis remain incompletely understood. Here we show that overexpression of ErbB-2 in human breast cancer cell lines leads to phosphorylation and activation of the semaphorin receptor Plexin-B1. This was required for ErbB-2–dependent activation of the pro-metastatic small GTPases RhoA and RhoC and promoted invasive behavior of human breast cancer cells. In a mouse model of ErbB-2–overexpressing breast cancer, ablation of the gene encoding Plexin-B1 strongly reduced the occurrence of metastases. Moreover, in human patients with ErbB-2–overexpressing breast cancer, low levels of Plexin-B1 expression correlated with good prognosis. Our data suggest that Plexin-B1 represents a new candidate therapeutic target for treating patients with ErbB-2–positive breast cancer.
Thomas Worzfeld, Jakub M. Swiercz, Mario Looso, Beate K. Straub, Kishor K. Sivaraj, Stefan Offermanns
Usage data is cumulative from April 2023 through April 2024.
Usage | JCI | PMC |
---|---|---|
Text version | 642 | 92 |
99 | 40 | |
Figure | 77 | 5 |
Supplemental data | 13 | 1 |
Citation downloads | 15 | 0 |
Totals | 846 | 138 |
Total Views | 984 |
Usage information is collected from two different sources: this site (JCI) and Pubmed Central (PMC). JCI information (compiled daily) shows human readership based on methods we employ to screen out robotic usage. PMC information (aggregated monthly) is also similarly screened of robotic usage.
Various methods are used to distinguish robotic usage. For example, Google automatically scans articles to add to its search index and identifies itself as robotic; other services might not clearly identify themselves as robotic, or they are new or unknown as robotic. Because this activity can be misinterpreted as human readership, data may be re-processed periodically to reflect an improved understanding of robotic activity. Because of these factors, readers should consider usage information illustrative but subject to change.