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BACKGROUND Prognostic markers of bone metastatic clear cell renal cell cancer (ccRCC) are poorly established. We tested prognostic value of HIF1α/HIF2α and their selected target genes in primary tumors and corresponding bone metastases. RESULTS Expression of HIF2α was lower in mRCC both at mRNA and protein levels (p/mRNA/=0.011, p/protein/=0.001) while HIF1α was similar to nmRCC. At the protein level, CAIX, GAPDH and GLUT1 were increased in mRCC. In all primary RCCs, low HIF2α and high HIF1α as well as CAIX, GAPDH and GLUT1 expressions correlated with adverse prognosis, while VEGFR2 and EPOR gene expressions were associated with favorable prognosis. Multivariate analysis confirmed high HIF2α protein expression as an independent risk factor. Prognostic validation of HIFs, LDH, EPOR and VEGFR2 in RNA-Seq data confirmed higher HIF1α gene expression in primary RCC as an adverse (p=0.07), whereas higher HIF2α and VEGFR2 expressions as favorable prognostic factors. HIF1α/HIF2α-index (HIF-index) proved to be an independent prognostic factor in both the discovery and the TCGA cohort. PATIENTS AND METHODS Expressions of HIF1α and HIF2α as well as their 7 target genes were analysed on the mRNA and protein level in 59 non-metastatic ccRCCs (nmRCC), 40 bone metastatic primary ccRCCs (mRCC) and 55 corresponding bone metastases. Results were validated in 399 ccRCCs from the TCGA project. CONCLUSIONS We identified HIF2α protein as an independent marker of the metastatic potential of ccRCC, however, unlike HIF1α, increased HIF2α expression is a favorable prognostic factor. The HIF-index incorporated these two markers into a strong prognostic biomarker of ccRCC.

Objective: To investigate the patterns of expression of the junctional proteins beta-catenin and claudins in different prognostic groups of patients with prostatic cancer, to determine their value as prognostic markers., Patients and Methods: We evaluated the samples of 30 patients who had a radical prostatectomy for organ-confined cancer (pT2N0M0), men with clinically advanced cancer, and a control group with benign prostatic hyperplasia. Using immunohistochemistry applied to tissue microarrays, each group was evaluated for claudin-1, -2, -3, -4, -5, -7, -8 and -10, and beta-catenin expression., Results: There were differences among the three groups in the expression of claudin-1 (P = 0.001), -2 (P = 0.014), -3 (P = 0.027), -4 (P = 0.001), -8 (P = 0.001) and beta-catenin (P = 0.002), regardless of Gleason score. By contrast, claudin-5, -7 and -10 patterns were not significantly different among the groups. Furthermore, claudin-1 (P = 0.014) and -4 (P = 0.004) could be used to distinguish between those patients who had metastases and those who did not., Conclusions: The pattern of claudin expression could be a novel diagnostic marker in re-classifying adenocarcinomas, and an additional sensitive predictive factor for a clinically poor prognosis. Our results suggest that patients with organ-confined and advanced cancer are subsets with distinct claudin expression profiles, and that claudin-4 is related to cellular differentiation in prostate cancer, which is not only the receptor molecule for the Clostridium perfringens enterotoxin, and thus a theoretical future therapeutic target for prostate cancer, but also a marker of progression.