¹Instituto de Investigaciones Biomédicas 'Alberto Sols', Arturo Duperier, 4, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, E-28029 Madrid, Spain

Correspondence: Professor A Muñoz, E-mail: amunoz@iib.uam.es

Received 3 December 2004; Revised 31 January 2005; Accepted 1 February 2005; Published online 15 March 2005.

Abstract

Vitamin D analogues with reduced hypercalcemic activity are under clinical investigation for use against colon cancer and other neoplasias. However, only a subset of patients responds to this therapy, most probably due to loss of vitamin D receptor (VDR) expression during tumour progression. Recent data show that SNAIL transcription factor represses VDR expression, and thus abolishes the antiproliferative and prodifferentiation effects of VDR ligands in cultured cancer cells and their antitumour action in xenografted mice. Accordingly, upregulation of SNAIL in human colon tumours associates with downregulation of VDR. These findings suggest that SNAIL may be associated with loss of responsiveness to vitamin D analogues and may thus be used as an indicator of patients who are unlikely to respond to this therapy.