title: Co-localization of GSTP1 and JNK in transitional cell carcinoma of urinary bladder.
abstract: Transitional cell carcinoma (TCC) of urinary bladder belongs to glutathione S-transferase P1 (GSTP1) overexpressing tumors. Upregulated GSTP1 in TCC is related to apoptosis inhibition. This antiapoptotic effects of GSTP1 might be mediated through protein:protein interaction with c-Jun NH(2) -terminal kinase (JNK). Herein, we analyzed whether a direct link between GSTP1 and JNK exists in TCC. The presence of GSTP1/JNK complexes was analyzed by immunoprecipitation and Western blotting in 20 TCC specimens, obtained after surgery. Co-localization of GSTP1 and JNK was also investigated in the 5637 TCC cell line by immunofluorescence confocal microscopy. By means of immunoprecipitation we show for the first time the presence of GSTP1/JNK complexes in all TCC samples studied. A co-localization of GSTP1 and JNK was also demonstrated in the 5637 TCC cell line by means of confocal microscopy. Protein-protein interactions, together with co-localization between GSTP1 and JNK provide evidence that GSTP1 most probably inhibits apoptosis in TCC cells by non-covalent binding to JNK.
authors.affiliation: Faculty of Medicine, Institute of Medical and Clinical Biochemistry, University of Belgrade, Belgrade Serbia.
authors.forename: Marija
authors.initials: M
authors.lastname: Pljesa-Ercegovac
authors.forename: Ana
authors.initials: A
authors.lastname: Savic-Radojevic
authors.forename: Tamara
authors.initials: T
authors.lastname: Kravic-Stevovic
authors.forename: Vladimir
authors.initials: V
authors.lastname: Bumbasirevic
authors.forename: Jasmina
authors.initials: J
authors.lastname: Mimic-Oka
authors.forename: Tatjana
authors.initials: T
authors.lastname: Simic