German investigators have reported that Karyopherin a2 (KPNA2) appears to be involved in the carcinogenesis of renal cell carcinoma (RCC) and may function as a novel prognostic indicator. Tim Müller, of the Institute of Pathology at the University Hospital Bonn, Bonn, Germany and colleagues, reported in Clinical Genitourinary Cancer that higher tumor stage and higher tumor grade may be correlated with high KPNA2 expression.1The researchers theorize that KPNA2 expression could be used in the future to stratify risk groups among patients with RCC.

The authors note that KPNA2 is involved in carcinogenesis through translocation of cancer-associated cargo proteins. Müller and colleagues investigated the protein expression of KPNA2 in cancerous and healthy renal tissues to determine its prognostic value in patients with RCC. They used a quantitative image analysis software to examine KPNA2 protein expression via immunohistochemistry in 240 patients with RCC. As part of their investigation, they also analyzed gene expression data from The Cancer Genome Atlas (TCGA).

The team found KPNA2 expression is elevated in a subset of clear cell RCC (ccRCC) and papillary RCC (pRCC) patients. High KPNA2 protein expression was associated with higher tumor stage and International Society of Urologic Pathology grade in ccRCC. They also found a correlation between high KPNA2 protein expression and shorter overall survival (OS) in ccRCC. However, the prognostic value of KPNA2 was not confirmed by multivariate Cox regression analysis in which the researchers tested it in conjunction with strong prognostic factors (tumor stage, lymph node metastasis, International Society of Urologic Pathology grade, and resection status). 

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  1. Müller T, Tolkach Y, Stahl D, et al. Karyopherin Alpha 2 Is an Adverse Prognostic Factor in Clear-Cell and Papillary Renal-Cell Carcinoma [published online October 23, 2018]Clin Genitourin Cancer. doi: 10.1016/j.clgc.2018.10.008