Nuclear localization of protein kinase CK2 catalytic subunit (CK2α) is associated with poor prognostic factors in human prostate cancer

Many genomic abnormalities have been identified in various subsets of prostate cancer, but until now, few genes have been associated with the progression of this cancer. High activity of protein serine/threonine kinase CK2 has been observed in various solid tumours and this alteration has been linked both to growth-related functions and to suppression of cellular apoptosis. Here, we provide the first evidence for a strong association between a nuclear localization of CK2α, evaluated by immunohistochemistry, and poor prognostic factors in a retrospective cohort of 131 human prostate adenocarcinomas. Nuclear CK2α localization is significantly correlated with higher Gleason score, more locally advanced disease (cT3-T4) and more perineural or lymphatic invasion (p < 0.0019 to 0.046). In contrast, despite a strong trend, no significant relationship was found between higher initial PSA and nuclear CK2α localization. Thus, this previously undescribed molecular heterogeneity is the first step in defining CK2 as both a potential biomarker and a promising target in human prostate cancer.