Novel role of thromboxane receptors beta isoform in bladder cancer pathogenesis

Cancer Res. 2008 Jun 1;68(11):4097-104. doi: 10.1158/0008-5472.CAN-07-6560.

Abstract

These studies were undertaken to determine the potential role of thromboxane receptors (TP) in bladder cancer. The data reported herein show that expression of the TP-beta receptor protein is increased in tissue obtained from patients with bladder cancer and associated with a significantly poorer prognosis (P < 0.005). Bladder cancer cell lines express the TP-beta isoform, unlike immortalized nontransformed urothelial cells (SV-HUC) that express only the TP-alpha isoform. TP-beta receptor expression, but not TP-alpha, promoted cell proliferation, migration, and invasion in vitro, and also resulted in malignant transformation of SV-HUC cells in vivo. Agonist-mediated phosphorylation of extracellular signal-regulated kinase and FAK was dependent on the expression of TP-beta. Furthermore, TP-beta mediated multiple biological effects by signaling through either G-protein alpha subunit 12 or beta-arrestin 2. Treatment of mice with the TP receptor antagonist GR32191, alone or in combination with cisplatin, significantly delayed tumor onset and prolonged survival of mice transplanted with TCC-SUP bladder cancer cells compared with vehicle or cisplatin alone. These results support the model that the TP-beta receptor isoform plays a unique role in bladder cancer progression and its expression may have predictive value and provide a novel therapeutic target.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Base Sequence
  • Cell Division
  • Cell Line, Tumor
  • Cell Movement
  • DNA Primers
  • Humans
  • Mice
  • Neoplasm Invasiveness
  • Protein Isoforms / physiology*
  • Receptors, Thromboxane / antagonists & inhibitors
  • Receptors, Thromboxane / metabolism
  • Receptors, Thromboxane / physiology*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Urinary Bladder Neoplasms / metabolism
  • Urinary Bladder Neoplasms / pathology
  • Urinary Bladder Neoplasms / physiopathology*

Substances

  • DNA Primers
  • Protein Isoforms
  • Receptors, Thromboxane