Abstract 2498: Detection of S-nitrosylated heat shock protein 90 in renal cell cancer

Purpose: Nitric oxide (NO) is a versatile signaling molecule. Its roles in a variety of physiological functions in mammals are beginning to be understood. It has been demonstrated that NO up-regulates the expression of the Fas receptor on human tumor cells via specific inactivation of transcription repressor YY1 DNA binding activity to the silencer region of the Fas promoter (Hermes G., et al. 2001). We also showed that inactivation of YY1 via protein S-nitrosylated by NO in prostatic cancer could be identified (Hongo F., et al. 2005). This post-translational modification, known as S-nitrosylation, has emerged as a highly conserved and spatiotemporally specific signaling mechanism. The objective of our study was to examine the effect of NO donor treatment on renal cell cancer. Methods: We examined the effect of the NO donor DETA-NONOate (100-500uM) on the following renal cell cancer cell lines; CAKI-1, NC65, and ACHN. Anti-S-nitroso-Cysteine antibody in the rabbit (SIGMA-ALDRICH) was applied as a primary antibody for immunohistochemistry. The biotin-switch technique was applied to detect specific S-nitrosylated proteins. Whole cell lysates were extracted from ACHN cells employed with DETA-NONOate. Using an S-nitrosylated detection kit (Cayman Chemical Company), S-NO was replaced by Biotin. Cell lysates were incubated at 4 oC with 30 μL of Dynabeads M-280 Streptavidin (Invitrogen) for 3 hrs. After five washes with wash buffer (S-Nitrosylation Wash buffer), the protein complex was eluted from anti-biotin dynabeads by incubation with 1x volume of elution buffer (0.1M glycine (pH2.0)) twice for 15 min. Each sample was added to an SDS-polyacrylamide gel for mass spectrometry. Results: Significant up-regulation of S-nitrosylated proteins employed with DETA-NONOate was observed by immunohistochemistry. Specific S-nitrosylated proteins in ACHN cells were detected by the biotin-switch technique and included HSP90 (heat shock protein 90), GRP78 (HSP70 family), HSP70, and pyruvate kinase M2. In ACNH cells, Significant up regulation of S-nitrosylated HSP90 by western blot. Conclusions: Our data showed that NO treatment significantly increased S-nitrosylation of several proteins. S-nitrosylation should be considered as one of the mechanisms by which NO acts on cancer cells. Citation Format: Fumiya Hongo, Takashi Ueda, Saya Ito-Ueda, Masakatsu Oishi, Terukazu Nakamura, Yoshio Naya, Tsuneharu Miki. Detection of S-nitrosylated heat shock protein 90 in renal cell cancer. [