Otoferlin is a prognostic biomarker in patients with clear cell renal cell carcinoma: A systematic expression analysis

Objectives: To comprehensively investigate the role of otoferlin as a prognostic and diagnostic biomarker in clear cell renal cell carcinoma. Methods: Three independent cohorts were used to study otoferlin in clear cell renal cell carcinoma: The Cancer Genome Atlas cohort (messenger ribonucleic acid expression; clear cell renal cell carcinoma n = 514, normal renal tissue n = 81); study validation cohort (messenger ribonucleic acid expression; clear cell renal cell carcinoma n = 79, normal renal tissue n = 44); and immunohistochemistry cohort (protein expression; clear cell renal cell carcinoma n = 142, normal renal tissue n = 30). Otoferlin gene expressions were extracted from The Cancer Genome Atlas database or determined using quantitative real-time polymerase chain reaction, respectively. Protein expression was assessed using immunohistochemistry staining against otoferlin on tissue microarrays. Correlations between otoferlin messenger ribonucleic acid/protein expression and clinicopathological data/patient survival were statistically tested. Results: Otoferlin messenger ribonucleic acid expression was significantly upregulated in clear cell renal cell carcinoma compared with normal renal tissue. High expression levels correlated with advanced stage, higher grade and metastatic tumors, accompanied by independent prognostic significance for overall and cancer-specific survival. In contrast, otoferlin protein expression was downregulated in tumor tissue. Although, high otoferlin expression in clear cell renal cell carcinoma was positively correlated with histological grading and independently predictive of a shortened progression-free survival. Conclusion: Our data suggest otoferlin as an indicator of tumor aggressiveness and as a prognostic biomarker for patients with clear cell renal cell carcinoma, leading to the conclusion that otoferlin could promote the malignancy of clear cell renal cell carcinoma

RNA Sequencing Reveals Alterations and Similarities in Cell Metabolism, Hypoxia and Immune Evasion in Primary Cell Cultures of Clear Cell Renal Cell Carcinoma

The treatment of advanced renal cell carcinoma remains a challenge. To develop novel therapeutic approaches, primary cell cultures as an in vitro model are considered more representative than commercial cell lines. In this study, we analyzed the gene expression of previously established primary cell cultures of clear cell renal cell carcinoma by bulk (3'm)RNA sequencing and compared it to the tissue of origin. The objectives were the identification of dysregulated pathways under cell culture conditions. Furthermore, we assessed the suitability of primary cell cultures for studying crucial biological pathways, including hypoxia, growth receptor signaling and immune evasion. RNA sequencing of primary cell cultures of renal cell carcinoma and a following Enrichr database analysis revealed multiple dysregulated pathways under cell culture conditions. 444 genes were significantly upregulated and 888 genes downregulated compared to the tissue of origin. The upregulated genes are crucial in DNA repair, cell cycle, hypoxia and metabolic shift towards aerobic glycolysis. A downregulation was observed for genes involved in pathways of immune cell differentiation and cell adhesion. We furthermore observed that 7275 genes have a similar mRNA expression in cell cultures and in tumor tissue, including genes involved in the immune checkpoint signaling or in pathways responsible for tyrosine kinase receptor resistance. Our findings confirm that primary cell cultures are a representative tool for specified experimental approaches. The results presented in this study give further valuable insights into the complex adaptation of patient-derived cells to a new microenvironment, hypoxia and other cell culture conditions, which are often neglected in daily research, and allow new translational and therapeutic approaches

N-6-Methyladenosine (m(6)A) readers are dysregulated in renal cell carcinoma

N-6-Methyladenosine (m(6)A) is the most common modification of messenger RNA (mRNA) in mammals. It critically influences RNA metabolism and plays an essential role in virtually all types of bioprocesses including gene expression, tissue development, self-renewal and differentiation of stem cells, stress response and circadian clock control. It plays a crucial role in carcinogenesis and could be used as a prognostic and a diagnostic tool and as a target for new anticancer therapies. m(6)A modification is dynamically and reversibly regulated by three types of proteins. Methyltransferases, so-called writers add a methyl group to the adenosine, which can be removed by demethylases, also called erasers. m(6)A-specific RNA-binding proteins, from here on referred to as readers, preferentially bind to the m(6)A site and mediate biological functions, such as translation, splicing or decay of RNA. In this study, we examined the expression of the six m(6)A readers HNRNPA2B1, HNRNPC, YTHDC1 and YTHDF1-3 in clear cell renal carcinoma (ccRCC). We show that on mRNA level the expression of all six m(6)A readers is significantly downregulated compared to normal renal tissue and on protein level five out of six readers are dysregulated. Lower levels of some m(6)A readers are correlated with advanced stage and grade as well as associated with a shorter overall, progression-free and cancer-specific survival. In summary, we could show that m(6)A readers are dysregulated in ccRCC and might therefore act as a tumor marker, could give further information on the individual prognosis and be a target of innovative cancer therapy

KDM5C Is Overexpressed in Prostate Cancer and Is a Prognostic Marker for Prostate-Specific Antigen-Relapse Following Radical Prostatectomy

Currently, few prognostic factors are available to predict the emergence of castration-resistant prostate cancer and no curative options are available. Epigenetic gene regulation has been shown to trigger prostate cancer metastasis and androgen independence. Histone lysine demethylases (KDMs) are epigenetic enzymes that can remove both repressive and activating histone marks. KDM5 family members are capable of removing the histone H3 Lysine 4 dimethylation-activating mark, rendering them potential players in the down-regulation of tumor suppressors and suggesting that their activity could repress oncogenes. Here, we systematically investigated KDM5C expression patterns in two independent radical prostatectomy cohorts (822 prostate tumors in total) by immunohistochemistry. Positive nuclear KDM5C staining was significantly associated with a reduced prostate-specific antigen relapse-free survival. Our study confirmed that nuclear KDM5C expression is an independent prognostic parameter. Most strikingly, the prognostic value of nuclear KDM5C expression for progression-free survival was exclusively pronounced for the Gleason group 7. In addition, KDM5C knockdown resulted in growth retardation of prostate cancer cells in vitro and induced regulation of several proliferation-associated genes. Our data indicate that KDM5C is functionally involved in proliferation control of prostate cancer cells and might represent a novel attractive therapy target. Moreover, overexpression of KDM5C is an independent new predictive marker for therapy failure as determined by biochemical recurrence in patients after prostatectomy