1. ¹Institut de Pharmacologie Moléculaire et Cellulaire, CNRS-UNSA UMR6097, Sophia Antipolis, Valbonne, France
2. ²INSERM-UMR S538, Université Pierre et Marie Curie – Paris6, Paris, France
3. ³AP-HP, Hôpital Saint-Antoine, Service d'Anatomie Pathologique, Paris, France
4. ⁴Center for Molecular Medicine, University of Connecticut Health Center, Farmington, CT, USA

Correspondence: Dr G Lambeau, Institut de Pharmacologie Moléculaire et Cellulaire, CNRS-UNSA UMR6097, 660 route des Lucioles, Sophia Antipolis, 06560 Valbonne, France. E-mail: lambeau@ipmc.cnrs.fr

Received 2 October 2007; Revised 12 December 2007; Accepted 12 December 2007; Published online 22 January 2008.

Abstract

Recent studies suggest that secreted phospholipases A₂ (sPLA₂s) represent attractive potential tumour biomarkers and therapeutic targets for various cancers. As a first step to address this issue in human colorectal cancer, we examined the expression of the full set of sPLA₂s in sporadic adenocarcinomas and normal matched mucosa from 21 patients by quantitative PCR and immunohistochemistry. In normal colon, PLA2G2A and PLA2G12A were expressed at high levels, PLA2G2D, PLA2G5, PLA2G10 and PLA2G12B at moderate levels, and PLA2G1B, PLA2G2F and PLA2G3 at low levels. In adenocarcinomas from left and right colon, the expression of PLA2G3 was increased by up to 40-fold, while that of PLA2G2D and PLA2G5 was decreased by up to 23- and 14-fold. The variations of expression for sPLA₂-IID, sPLA₂-III and sPLA₂-V were confirmed at the protein level. The expression pattern of these sPLA₂s appeared to be linked respectively to the overexpression of interleukin-8, defensin 6, survivin and matrilysin, and downregulation of SFRP-1 and RLPA-1, all these genes being associated to colon cancer. This original sPLA₂ profile observed in adenocarcinomas highlights the potential role of certain sPLA₂s in colon cancer and suggests that sPLA₂-III might be a good candidate as a novel biomarker for both left and right colon cancers.