Endothelin receptor blockade inhibits proliferation of Kaposi's sarcoma cells

Anna Bagnato, Laura Rosanò, Valeriana Di Castro, Adriana Albini, Debora Salani, Marco Varmi, Maria Rita Nicotra, Pier Giorgio Natali

Research output: Contribution to journalArticlepeer-review

Abstract

Endothelin-1 (ET-1) has been shown to be mitogenic for endothelial and several tumor cells through an autocrine mechanism. In this study we evaluated whether the tumorigenic KS IMM cell line deriving from Kaposi's sarcoma (KS), a highly angiogenic tumor, is susceptible to ET-1 mitogenic activity. By reverse transcriptase-polymerase chain reaction, we detected ET-1 mRNA expression and both ETA receptor (ETAR) and ETBR mRNA transcripts in the KS IMM cells. High concentrations of ET-1 are released from the KS IMM cells and competition-binding studies demonstrated that these cells also express functional ETAR and ETBR with high affinity for ET-1 and ET-1/ET-3, respectively. Expression of ET-1 and cognate receptors could be detected by immunohistochemical method in vitro, in KS IMM xenograft, and in tissue sections of a human KS lesion. Furthermore ET-1 induces a marked and dose-dependent increase in [3H]thymidine incorporation comparable to that elicited by vascular endothelial growth factor. Addition of both selective ETBR antagonist (BQ 788) and ETAR antagonist (BQ 123), completely blocked ET-1-induced mitogenic response and reduced the basal growth rate of unstimulated cells, suggesting that both receptors mediated the proliferative signal. Such findings demonstrate that ET-1 participates on KS pathogenesis acting as an autocrine growth factor and that ET-1 receptor antagonists may thus be novel candidates for therapeutic intervention.

Original languageEnglish
Pages (from-to)841-847
Number of pages7
JournalAmerican Journal of Pathology
Volume158
Issue number3
Publication statusPublished - 2001

ASJC Scopus subject areas

  • Pathology and Forensic Medicine

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