title: Antiproliferative and apoptotic effects of telmisartan in human colon cancer cells.
abstract: Telmisartan is an angiotensin I (AT1) receptor blocker used in the treatment of essential hypertension, with partial peroxisome proliferator-activated receptor γ (PPARγ) agonism. In prior studies, PPARγ activation led to apoptosis and cell cycle inhibition in various cancer cells. The aim of the present study was to investigate the potential antiproliferative and apoptotic effects of telmisartan by partially activating PPARγ. HT-29, SW-480 and SW-620 cells were incubated with telmisartan (0.2-5 μM) or the full agonist, pioglitazone (0.2-5.0 μM). The antiproliferative and apoptotic effects of telmisartan in the human colon cancer cells were significant at therapeutic serum concentrations, and telmisartan exhibited a potency at least equivalent to the full PPARγ agonist, pioglitazone. The antiproliferative and apoptotic effects of pioglitazone in the human colon cancer cells were not completely deregulated by PPARγ blockade with GW9662. In the telmisartan-treated cells, PPARγ blockade resulted in an increased antiproliferative and apoptotic effect. These effects are not entirely explained by PPARγ activation, however, possible hypotheses that require further experimental investigation are as follows: i) Ligand-independent PPARγ activation through the activation-function 1 domain; ii) a PPARγ-independent mechanism; or iii) independent antiproliferative and apoptotic effects through GW9662.
authors.affiliation: Department of General, Visceral and Vascular Surgery, Campus Benjamin Franklin, Charité-University of Medicine Berlin, Berlin D-12203, Germany.
authors.forename: Lucas D
authors.initials: LD
authors.lastname: Lee
authors.affiliation: Department of General, Visceral and Vascular Surgery, Campus Benjamin Franklin, Charité-University of Medicine Berlin, Berlin D-12203, Germany.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Mafura
authors.affiliation: Department of General, Visceral and Vascular Surgery, Campus Benjamin Franklin, Charité-University of Medicine Berlin, Berlin D-12203, Germany.
authors.forename: Johannes C
authors.initials: JC
authors.lastname: Lauscher
authors.affiliation: Department of General, Visceral and Vascular Surgery, Campus Benjamin Franklin, Charité-University of Medicine Berlin, Berlin D-12203, Germany.
authors.forename: Hendrik
authors.initials: H
authors.lastname: Seeliger
authors.affiliation: Department of General, Visceral and Vascular Surgery, Campus Benjamin Franklin, Charité-University of Medicine Berlin, Berlin D-12203, Germany.
authors.forename: Martin E
authors.initials: ME
authors.lastname: Kreis
authors.affiliation: Department of General, Visceral and Vascular Surgery, Campus Benjamin Franklin, Charité-University of Medicine Berlin, Berlin D-12203, Germany.
authors.forename: Jörn
authors.initials: J
authors.lastname: Gröne
keywords: angiotensin I receptor blocker; antiproliferative; apoptosis; colon cancer; peroxisome proliferator-activated receptor γ; telmisartan