Serum protein kinase Cα as a diagnostic biomarker of cancers

Article type: Research Article

Authors: Kang, Jeong-Hun^{a; 1; 2; *} | Mori, Takeshi^{a; b; 1} | Kitazaki, Hirotaro^{c; 1} | Niidome, Takuro^{a; b} | Takayama, Koichi^d | Nakanishi, Yoichi^d | Katayama, Yoshiki^{a; b; c; e; *}

Affiliations: [a] Department of Applied Chemistry, Kyushu University, Fukuoka, Japan | [b] Center for Future Chemistry, Kyushu University, Fukuoka, Japan | [c] Graduate School of Systems Life Sciences, Kyushu University, Fukuoka, Japan | [d] Research Institute for Diseases of the Chest, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan | [e] International Research Center for Molecular Systems, Fukuoka, Japan

Correspondence: [*] Corresponding authors: Jeong-Hun Kang and Yoshiki Katayama, Department of Applied Chemistry, Faculty of Engineering, Kyushu University, 744 Motooka, Nishi-Ku, Fukuoka 819-0395, Japan. Tel.: +81 92 802 2850; Fax: +81 92 802 2850; E-mail: jrjhkang@ncvc.go.jp; ykatatcm@mail.cstm.kyushu-u.ac.jp.

Note: [1] These authors contributed equally to this work.

Note: [2] Present address: Department of Biomedical Engineering, National Cerebral and Cardiovascular Center Research Institute, 5-7-1 Fujishiro-dai, Suita, Osaka 565-8565, Japan.

Abstract: Background:Several serum biomarkers such as antigens, soluble proteins, metabolites, and genes have been identified for the diagnosis of cancers and for monitoring the recurrence after cancer treatment. Methods:In the present study, a protein kinase C (PKC) α-specific peptide substrate was phosphorylated with serum samples collected from cancer-bearing mice (U87, A431, HepG2, and A549) and the phosphorylation ratio was detected by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS). Results:The phosphorylation ratio for peptide substrates significantly increased in the serum of cancer-bearing mice compared with the ratio found in control mice. The addition of a PKCα inhibitor induced a concentration-dependent decrease in phosphorylation ratios, but the non-PKCα inhibitors, rottlerin and H-89, did not significantly effect phosphorylation ratios. Conclusions:These results suggest that serum activated PKCα is a good biomarker applicable to cancer diagnosis.

Keywords: Diagnosis, protein kinase, serum, peptide substrate, phosphorylation

DOI: 10.3233/CBM-130340

Journal: Cancer Biomarkers, vol. 13, no. 2, pp. 99-103, 2013