More precise prediction in Chinese patients with penile squamous cell carcinoma: protein kinase CK2α catalytic subunit (CK2α) as a poor prognosticator

// Zai-Shang Li 1, 2, 3, * , Chuang-Zhong Deng 1, 2, 3, * , Yun-Lin Ye 1, 2, 3, * , Kai Yao 1, 2, 3 , Sheng-Jie Guo 1, 2, 3 , Jie-Ping Chen 1, 2, 3 , Yong-Hong Li 1, 2, 3 , Zi-Ke Qin 1, 2, 3 , Zhuo-Wei Liu 1, 2, 3 , Bin Wang 4 , Qi Zhao 1, 2, 5 , Peng Chen 6 , Qi-Wu Mi 7 , Xiao-Feng Chen 8 , Hui Han 1, 2, 3 and Fang-Jian Zhou 1, 2, 3 1 Department of Urology, Sun Yat-sen University Cancer Center, Guangzhou, P. R. China 2 State Key Laboratory of Oncology in Southern China, Guangzhou, P. R. China 3 Collaborative Innovation Center of Cancer Medicine, Guangzhou, P. R. China 4 Department of Urology, Cancer Center of Guangzhou Medical University, Guangzhou, P. R. China 5 School of Life Science, Sun Yat-sen University, Guangzhou, P. R. China 6 Department of Urology, Affiliated Tumor Hospital of Xinjiang Medical University, Urumchi, P. R. China 7 Department of Urology, Dong Guan People’s Hospital, Guang Dong, P. R. China 8 Department of Urology, The First People's Hospital of Chenzhou, Chenzhou, P. R. China * First authors, they contributed equally to this research Correspondence to: Hui Han, email: hanhui@sysucc.org.cn Fang-Jian Zhou, email: zhoufj@sysucc.org.cn Keywords: casein kinase 2α, penile neoplasm, squamous cell carcinoma Received: September 13, 2016      Accepted: February 21, 2017      Published: May 16, 2017 ABSTRACT Purpose: In this study, we assess the CK2α expression in human penile squamous cell carcinoma (SCC) and its clinical significance. Methods: A total of 157 human penile SCC tissue samples were immunohistochemically analyzed. In addition, 12 human penile SCC and adjacent normal tissues were examined for CK2α protein and mRNA expression by Western blotting and real-time quantitative PCR, respectively. Survival was analyzed using the Kaplan-Meier test and the log-rank test. Multivariate Cox proportional hazard regression analysis was performed to determine the impacts of CK2α expression and the clinicopathological features on patient disease-specific survival (DSS). Likelihood ratios (LRs), Akaike information criterion (AIC) values, and concordance indexes (C-indexes) were investigated to evaluate the accuracies of the factors. Bootstrap-corrected C-indexes were used for internal validation (with sampling 1000 times). Results: A significant difference in the distribution of CK2α was observed between the normal and penile carcinoma tissues ( P <0.001). CK2α expression was associated with the pathological T and N stages in the penile cancer tissues ( P <0.001). High CK2α expression was with significantly poorer DSS compared with low expression one ( P <0.001). Western blotting and real-time quantitative PCR also confirmed that CK2α expression was increased in the penile cancer tissues. In multivariate Cox regression analysis, CK2α overexpression still was one of independent prognostic factors for penile SCC ( P =0.005). The predictive accuracy of CK2α was verified by analysis of the C-indexes. Conclusion: High protein kinase CK2α expression is associated with several prognostic factors and is thus a significant indicator of poor prognosis for penile cancer.