Isabella Syring

Circulating Serum miRNA (miR-367-3p, miR-371a-3p, miR-372-3p and miR-373-3p) as Biomarkers in Patients with Testicular Germ Cell Cancer

PURPOSE Classic serum tumor markers (human chorionic gonadotropin, α1-fetoprotein and lactate dehydrogenase) have an important role in managing testicular germ cell tumor. Since only 60% of all patients with testicular germ cell tumor have elevations of these markers, there is a need for new biomarkers with greater sensitivity/specificity. miRNAs are deregulated in cancer and could serve as noninvasive serum biomarkers. We explored the role of serum miRNAs as a novel biomarker in patients with testicular germ cell tumor. MATERIALS AND METHODS Total RNA was isolated from serum. miRNA levels were quantified by quantitative real-time polymerase chain reaction. We assessed the miRNAs miR-302a-3p, 302b-3p, 302c-3p, 367-3p, 371a-3p, 372-3p and 373-3p in a subcohort of 30 patients with testicular germ cell tumor and 18 healthy subjects. Validation was performed in 76 patients treated with inguinal exploration due to suspicion of testicular germ cell tumor, of whom 59 had cancer and 17 had benign disease, and in 84 healthy male subjects. RESULTS Serum miR-367-3p, 371a-3p, 372-3p and 373-3p levels were significantly increased in patients with testicular germ cell tumor compared to healthy individuals and patients with nonmalignant testicular disease. In particular miR-371a-3p allowed for sensitive (84.7%) and specific (99%) identification of patients with testicular germ cell tumor, thus, outperforming human chorionic gonadotropin or α1-fetoprotein testing. Furthermore, miR-367-3p was increased in nonseminoma compared to seminoma cases. Serum miRNA levels were increased in patients with advanced local stage and metastasis. In 9 patients with localized (clinical stage 1A) testicular germ cell tumor serum miR-371a-3p levels decreased postoperatively, indicating tumor specific release. CONCLUSIONS miR-371a-3p allows for better identification of testicular germ cell tumor than α1-fetoprotein and human chorionic gonadotropin. It could be helpful for clinically managing testicular germ cell tumor, especially for monitoring surveillance therapy and residual disease after chemotherapy.

Pan-Cancer Analysis of the Mediator Complex Transcriptome Identifies CDK19 and CDK8 as Therapeutic Targets in Advanced Prostate Cancer

Purpose: The Mediator complex is a multiprotein assembly, which serves as a hub for diverse signaling pathways to regulate gene expression. Because gene expression is frequently altered in cancer, a systematic understanding of the Mediator complex in malignancies could foster the development of novel targeted therapeutic approaches. Experimental Design: We performed a systematic deconvolution of the Mediator subunit expression profiles across 23 cancer entities (n = 8,568) using data from The Cancer Genome Atlas (TCGA). Prostate cancer–specific findings were validated in two publicly available gene expression cohorts and a large cohort of primary and advanced prostate cancer (n = 622) stained by immunohistochemistry. The role of CDK19 and CDK8 was evaluated by siRNA-mediated gene knockdown and inhibitor treatment in prostate cancer cell lines with functional assays and gene expression analysis by RNAseq. Results: Cluster analysis of TCGA expression data segregated tumor entities, indicating tumor-type–specific Mediator complex compositions. Only prostate cancer was marked by high expression of CDK19. In primary prostate cancer, CDK19 was associated with increased aggressiveness and shorter disease-free survival. During cancer progression, highest levels of CDK19 and of its paralog CDK8 were present in metastases. In vitro, inhibition of CDK19 and CDK8 by knockdown or treatment with a selective CDK8/CDK19 inhibitor significantly decreased migration and invasion. Conclusions: Our analysis revealed distinct transcriptional expression profiles of the Mediator complex across cancer entities indicating differential modes of transcriptional regulation. Moreover, it identified CDK19 and CDK8 to be specifically overexpressed during prostate cancer progression, highlighting their potential as novel therapeutic targets in advanced prostate cancer. Clin Cancer Res; 23(7); 1829–40. ©2016 AACR.

MED12 overexpression is a frequent event in castration-resistant prostate cancer

In a recent effort to unravel the molecular basis of prostate cancer (PCa), Barbieri and colleagues using whole-exome sequencing identified a novel recurrently mutated gene, MED12, in 5.4% of primary PCa. MED12, encoding a subunit of the Mediator complex, is a transducer of Wnt/β-catenin signaling, linked to modulation of hedgehog signaling and to the regulation of transforming growth factor beta (TGFβ)-receptor signaling. Therefore, these studies prompted us to investigate the relevance of MED12 in PCa. Expression of MED12, SMAD3 phosphorylation, and proliferation markers was assessed by immunohistochemistry on tissue microarrays from 633 patients. siRNA-mediated knockdown of MED12 was carried out on PCa cell lines followed by cellular proliferation assays, cell cycle analysis, apoptosis assays, and treatments with recombinant TGFβ3. We found nuclear overexpression of MED12 in 40% (28/70) of distant metastatic castration-resistant prostate cancer (CRPC(MET)) and 21% (19/90) of local-recurrent CRPC (CRPC(LOC)) in comparison with frequencies of less than 11% in androgen-sensitive PCa, and no overexpression in benign prostatic tissues. MED12 expression was significantly correlated with high proliferative activity in PCa tissues, whereas knockdown of MED12 decreased proliferation, reduced G1- to S-phase transition, and increased the expression of the cell cycle inhibitor p27. TGFβ signaling activation associates with MED12 nuclear overexpression in tissues and results in a strong increase in MED12 nuclear expression in cell lines. Furthermore, MED12 knockdown reduced the expression of the TGFβ target gene vimentin. Our findings show that MED12 nuclear overexpression is a frequent event in CRPC in comparison with androgen-sensitive PCa and is directly implicated in TGFβ signaling.

Comprehensive analysis of the transcriptional profile of the Mediator complex across human cancer types

The Mediator complex is a key regulator of gene transcription and several studies demonstrated altered expressions of particular subunits in diverse human diseases, especially cancer. However a systematic study deciphering the transcriptional expression of the Mediator across different cancer entities is still lacking. We therefore performed a comprehensive in silico cancer vs. benign analysis of the Mediator complex subunits (MEDs) for 20 tumor entities using Oncomine datasets. The transcriptional expression profiles across almost all cancer entities showed differentially expressed MEDs as compared to benign tissue. Differential expression of MED8 in renal cell carcinoma (RCC) and MED12 in lung cancer (LCa) were validated and further investigated by immunohistochemical staining on tissue microarrays containing large numbers of specimen. MED8 in clear cell RCC (ccRCC) associated with shorter survival and advanced TNM stage and showed higher expression in metastatic than primary tumors. In vitro, siRNA mediated MED8 knockdown significantly impaired proliferation and motility in ccRCC cell lines, hinting at a role for MED8 to serve as a novel therapeutic target in ccRCC. Taken together, our Mediator complex transcriptome proved to be a valid tool for identifying cancer-related shifts in Mediator complex composition, revealing that MEDs do exhibit cancer specific transcriptional expression profiles.

MED15 overexpression in prostate cancer arises during androgen deprivation therapy via PI3K/mTOR signaling

Androgen deprivation therapy (ADT) is the main therapeutic option for advanced prostate cancer (PCa). After initial regression, most tumors develop into castration-resistant PCa (CRPC). Previously, we found the Mediator complex subunit MED15 to be overexpressed in CRPC and to correlate with clinical outcome. Therefore, we investigated whether MED15 is implicated in the signaling changes taking place during progression to CRPC. Immunohistochemistry (IHC) for MED15 on matched samples from the same patients before and after ADT reveals significantly increased MED15 expression after ADT in 72%. A validation cohort comprising samples before and after therapy confirmed our observations. Protein analysis for pAKT and pSMAD3 shows that MED15 correlates with PI3K and TGFß activities, respectively, and that hyper-activation of both pathways simultaneously correlates with highest levels of MED15. We further show that MED15 protein expression increases in LNCaP cells under androgen deprivation, and via EGF mediated PI3K activation. PI3K/mTOR and TGFß-receptor inhibition results in decreased MED15 expression. MED15 knockdown reduces LNCaP cell viability and induces apoptosis during androgen deprivation, while cell cycle is not affected. Collectively, MED15 overexpression arises during ADT via hyper-activation of PI3K/mTOR signaling, thus MED15 may serve as a predictive marker for response to PI3K/mTOR inhibitors. Furthermore, MED15 is potentially a therapeutic target for the treatment of CRPC.

Mediator Complex Subunit MED1 Protein Expression Is Decreased during Bladder Cancer Progression

Introduction Bladder cancer (BCa) is among the most frequent cancer entities and relevantly contributes to cancer-associated deaths worldwide. The multi-protein Mediator complex is a central regulator of the transcriptional machinery of protein-coding genes and has been described to be altered in several malignancies. MED1, a subunit of the tail module, was described to negatively modulate expression of metastasis-related genes and to be downregulated in melanoma and lung cancer. In contrast, MED1 hyperactivity was described in breast and prostate cancer, likely due its function as a hub for nuclear hormone receptors. So far, only little is known about the function of the Mediator complex in BCa. The aim of this study was therefore to investigate the role of MED1 in BCa as a prognostic biomarker and a biomarker of disease progression. Methods The protein expression of MED1 was assessed by immunohistochemistry (IHC) on tissue microarrays from 224 patients: benign urothelium n = 31, non-muscle invasive BCa (pTis, pT1) n = 72, and muscle invasive BCa (pT2–T4) n = 121. Comprehensive clinicopathological information including follow-up were available. Quantification of MED1 protein expression was evaluated by the semiquantitative image analysis program Definiens. Results MED1 expression significantly decreased during BCa progression from benign urothelium to advanced BCa. Muscle invasion, the crucial step in BCa progression, was associated with low MED1 protein expression. Accordingly, decreased MED1 expression was found in primary BCa samples with positive lymphonodal status and distant metastases. Furthermore, cancer-specific survival was significantly worse in the group of low MED1 expression. Conclusion Our findings show that the downregulation of MED1 is associated with muscle invasion, metastatic spread, and shorter overall survival in BCa.

Influence of Body Mass Index on Clinical Outcome Parameters, Complication Rate and Survival after Radical Cystectomy: Evidence from a Prospective European Multicentre Study

Background/Aims/Objectives: To evaluate the influence of body mass index (BMI) on complications and oncological outcomes in patients undergoing radical cystectomy (RC). Methods: Clinical and histopathological parameters of patients have been prospectively collected within the “PROspective MulticEnTer RadIcal Cystectomy Series 2011”. BMI was categorized as normal weight (<25 kg/m2), overweight (≥25–29.9 kg/m2) and obesity (≥30 kg/m2). The association between BMI and clinical and histopathological endpoints was examined. Ordinal logistic regression models were applied to assess the influence of BMI on complication rate and survival. Results: Data of 671 patients were eligible for final analysis. Of these patients, 26% (n = 175) showed obesity. No significant association of obesity on tumour stage, grade, lymph node metastasis, blood loss, type of urinary diversion and 90-day mortality rate was found. According to the American Society of Anesthesiologists score, local lymph node (NT) stage and operative case load patients with higher BMI had significantly higher probabilities of severe complications 30 days after RC (p = 0.037). The overall survival rate of obese patients was superior to normal weight patients (p = 0.019). Conclusions: There is no evidence of correlation between obesity and worse oncological outcomes after RC. While obesity should not be a parameter to exclude patients from cystectomy, surgical settings need to be aware of higher short-term complication risks and obese patients should be counselled accordingly.

The knockdown of the Mediator complex subunit MED15 restrains urothelial bladder cancer cells' malignancy

The Mediator complex, a multi-subunit protein complex, plays an integral role in regulating transcription. Genetic alterations of the mediator subunit 15 (MED15) in separate tumor entities have been described previously. However, till now, not much is known about the role of MED15 in urothelial bladder cancer (BCa). Using cBioPortal, database analysis was executed for the mRNA expression and survival analysis of MED15 in BCa. Immunohistochemistry (IHC) analysis against MED15 was performed on tissue microarrays with 18 benign, 126 BCa, and 38 metastases samples. The intensity evaluation was performed using a staining intensity score from 0 to 3 and associated with clinicopathological data. The BCa cell lines T24 and TCCSUP were used for the functional investigation. After the MED15 knockdown by small interfering (si)RNA, cell proliferation, migration and invasion were investigated. On the mRNA level, only a low number of alterations (2%) was found for MED15 in BCa. Due to the small count of events, there were no significant differences or tendencies in survival. For IHC, MED15 was found to have a higher expression in non-muscle invasive BCa compared with benign and muscle invasive BCa. For survival analysis, no significant differences between samples with or without overexpression of MED15 were found. In the functional analysis, proliferation, migration, and invasion were significantly reduced in BCa-cells following the transient siRNA-mediated MED15 knockdown. In summary, MED15 appears to play a role in the tumor parameters proliferation, migration, and invasion in BCa, but further investigations are necessary.

The knockdown of the mediator complex subunit MED30 suppresses the proliferation and migration of renal cell carcinoma cells

BACKGROUND The mediator complex consists of 33 subunits and plays a central role in transcription. Studies have already described the involvement of individual subunits, especially in carcinogenesis. With regard to the subunit MED30, this has, so far, only been confirmed in gastric and breast carcinoma. The role of MED30 in urological tumours is unknown. MATERIALS AND METHODS First, a database analysis using cBioPortal was performed for the mRNA expression and survival analysis of MED30 in clear cell renal cell carcinoma (ccRCC) and papillary RCC (pRCC). The immunohistochemical analysis (IHC) against MED30 was performed on tissue microarrays (TMA), with benign, ccRCC, pRCC samples, and ccRCC-metastases. Intensity evaluation was performed using the IRS (Immunoreactive Score). The ccRCC cell lines ACHN and A-498 were used for the functional investigation of proliferation, migration, and invasion after the knockdown of MED30 by siRNA. RESULTS In a database analysis by cBioPortal, it was shown that mRNA overexpression of MED30 in the pRCC was significantly associated with a poorer overall survival and progression-free survival. In the IHC, pRCC showed the highest level of MED30 expression, unfortunately without significant results in the survival analysis. The knockdown of MED30 resulted in a significant decrease in proliferation, migration, and invasion in ccRCC. CONCLUSION In summary, MED30 seems to be involved in the progression of the RCC.

756 The Mediator complex subunit MED12 is implicated in the progression of urothelial cell carcinoma of the urinary bladder

INTRODUCTION AND OBJECTIVES: Epigenetic changes, including promoter CpG island hypermethylation, occur frequently in bladder cancer (BC) and may be exploited as a means for BC detection and distinction between high-grade (HG) and low-grade (LG) disease. METHODS: To determine epigenetic differences between LG and HG BC we performed genome-wide methylation analysis with Agilent Human CpG Island Microarrays on a panel of fresh frozen BC tissue samples. Using Linear Models for Microarray Data (LIMMA) and local-pooled-error (LPE) approaches and unsupervised hierarchical clustering we identified 990 probes comprising a 32-gene panel that completely distinguished LG from HG BC based on methylation status. We selected five representative differentially methylated genes (DMGs) from our 32-gene panel for methylation validation by real-time PCRbased MethyLight in a series of 40 LG cases ageand sex-matched to 40 HG cases. RESULTS: Among the DMGs tested, including EOMES, GP5, PAX6, TCF4, and ZSCAN12, we identified that EOMES, GP5, and ZSCAN12 methylation significantly differs between normal, LG, and HG disease. GP5 and ZSCAN12, two novel methylated genes in BC, are significantly hypermethylated in HG versus LG BC (p1⁄40.006 and 0.028, respectively). Pathway enrichment analysis and functional annotation determined the most frequently methylated pathways in HG BC were enriched for anterior/posterior pattern specification, embryonic skeletal system development, and neuron fate commitment. The molecular functions of the most enriched genes were involved in DNA binding and transcription factor activity. CONCLUSIONS: These results indicate the ability to distinguish normal tissue from cancer, as well as LG from HG tumours, and reveal important pathways dysregulated in HG BC. Ultimately, the creation of a methylation panel able to distinguish between disease phenotypes will improve disease management and patient outcomes.