Identification of novel vascular markers through gene expression profiling of tumor-derived endothelium

Carmen Ghilardi¹ , Giovanna Chiorino² , Romina Dossi¹ , Zsuzsanna Nagy³ , Raffaella Giavazzi¹ and MariaRosa Bani¹

¹Laboratory of Biology and Treatment of Metastases, Mario Negri Institute for Pharmacological Research, Milano, Italy

²Laboratory of Cancer Genomics, Fondo "Edo Tempia", Biella, Italy

³Neuroscience Division, Medical School, University of Birmingham, Birmingham, B15 2TT, UK

author email corresponding author email

BMC Genomics 2008, 9:201doi:10.1186/1471-2164-9-201


Published:	30 April 2008

Abstract

Background

Targeting tumor angiogenesis and vasculature is a promising strategy for the inhibition of tumor growth and dissemination. Evidence suggests that tumor vasculature expresses unique markers that distinguish it from normal vasculature. Our efforts focused on the molecular characterization of endothelial cells (EC) in the search for selective markers of tumor vasculature that might be helpful for the development of effective therapeutic approaches.

Results

We investigated by microarray analysis the gene expression profiles of EC purified and cultured from tumor (ovarian carcinoma [HOC-EC]) and normal (human adrenal gland [HA-EC]) tissue specimens. We found distinct transcriptional features characterizing the EC of different origin, and identified 158 transcripts highly expressed by HOC-EC. We analyzed four of these genes, ADAM23, FAP, GPNMB and PRSS3, which were not previously known to be expressed by endothelium. In vitro experiments confirmed the higher expression of the selected genes in tumor-derived endothelium with no expression in tumor cells. In vivo investigation by in situ hybridization established that ADAM23, GPNMB and PRSS3 expression is localized on blood vessels of human cancer specimens.

Conclusion

These findings elucidate some of the molecular features of the tumor endothelium. Comparative transcriptomic analysis allowed us to determine molecular differences of tumor and normal tissue-derived endothelium and to identify novel markers that might be exploited to selectively target tumor vasculature.