Vimentin 3 and endothelin in prostate cancer.

Abstract

349 Background: An upregulation of vimentin 3, a truncated version of the full length vimentin, with an unknown function, was previously described by our group, in a direct dependency of increased ET-1 levels. We analyzed now vimentin 3 in further genitourinary cancers. Here, we describe our findings how vimentin 3 is part of the signaling pathways from Endothelin-1 (ET-1) and the Endothelin-A-Receptor (ETAR) and how it correlates with aggressive tumor behavior in a PCa cell culture and in human tissue and serum samples from PCa patients. Methods: DU145 cells were cultured. We stimulated with ET-1 with and without artificial downregulation of the ETAR, the ETBR or both receptors. A scratch assay was performed to demonstrate the influence of ET-1. Proteins were then extracted and WB for vimentin full length and vimentin 3 was performed. Additionally we analyzed ET-1 and vimentin 3 in serum from prostate cancer patients using ELISA and we did IF and IHC staining for vimentin 3 in human prostate cancer tissue. Results: Treatment with ET-1 and downregulation of the ETBR lead to a significant increased migration of DU145 cells after 3 and 6 h. The corresponding WB showed increased vimentin 3. ELISA showed increased levels of ET-1 in samples of prostate cancer patients compared to patients with no cancer history. ELISA could also demonstrate elevated levels of vimentin 3 in serum of patients with local disease and significantly elevated values in metastatic prostate cancer patients compared to patients with no cancer history. Conclusions: The data presented shows that ET-1 stimulation leads to overexpression of vimentin 3 in prostate cancer cell cultures and a concomitant aggressive biological behavior. Here we previously described the direct interaction of Vimentin 3 in prostate cancer and the activation mechanism via ET-1 and the ETAR. IHC, IF show an upregulation of the truncated variant Vimentin3 in tissue samples. In an Vimentin 3 ELISA we could show that this truncated variant is increased and therefore represents a potential biomarker. Highest values of vimentin 3 were measured using ELISA in serum of patients with recurrent and metastatic disease also suggesting that vimentin 3 correlates with aggressive tumor behavior.