Heat-shock protein 27 (Hsp27) as a target of methylglyoxal in gastrointestinal cancer

Tomoko Oya-Ito (1, 2) , Yuji Naito (2) , Tomohisa Takagi (2) , Osamu Handa (2) , Hirofumi Matsui (3) , Masaki Yamada , Keisuke Shima , Toshikazu Yoshikawa (1, 2)

1 Department of Medical Proteomics
2 Department of Molecular Gastroenterology and Hepatology
3 Division of Gastroenterology

The molecular mechanisms underlying the posttranslational modification of proteins in gastrointestinal cancer are still unknown. Here, we investigated the role of methylglyoxal (MG) modifications in gastrointestinal tumors. MG is a reactive dicarbonyl compound produced from cellular glycolytic intermediates that reacts non-enzymatically with proteins. By using a monoclonal antibody to MG-modified proteins, we found that murine heat-shock protein 25 (Hsp25) and human Hsp27 were the major adducted proteins in rat gastric carcinoma mucosal cell line and human colon cancer cell line, respectively. Furthermore, we found that Hsp27 was modified by MG in ascending colon and rectum of patients with cancer. However, MG-modified Hsp25/Hsp27 was not detected in non cancerous cell lines or in normal subject. MALDI-MS/MS analysis of peptide fragments identified Arg-75, Arg-79, Arg-89, Arg-94, Arg-127, Arg-136, Arg-140, Arg-188, and Lys-123 as MG modification sites in Hsp27 and in phosphorylated Hsp27. The transfer of MG-modified Hsp27 into rat intestinal epithelial cell line RIE was even more effective in preventing apoptotic cell death than that of native control Hsp27. Furthermore, MG modification of Hsp27 protected the cells against the both hydrogen peroxide- and cytochrome -mediated caspase activation, and the hydrogen peroxide-induced production of intracellular reactive oxygen species. The levels of lactate converted from MG were increased in carcinoma mucosal cell lines. Our results suggest that posttranslational modification of Hsp27 by MG may have important implications for epithelial cell injury in gastrointestinal cancer.

Mots clés: MG; Hsp25; Hsp27; AGEs; RGM; RIE; YAMC; MG-Hsp27; ROS; MALDI-MS; APF; FACS; posttranslational modification; glycation; proteomics; heat-shock protein 27; methylglyoxal; apoptosis; phosphorylation; cancer

Domaines: Biochimie, Biologie Moléculaire

Tomoko Oya-Ito, Yuji Naito, Tomohisa Takagi, Osamu Handa, Hirofumi Matsui, et al.. Heat-shock protein 27 (Hsp27) as a target of methylglyoxal in gastrointestinal cancer. Biochimica et Biophysica Acta - Molecular Basis of Disease, 2011, ⟨10.1016/j.bbadis.2011.03.017⟩. ⟨hal-00694726⟩