The Oncogenic Protein Kinase/ATPase RIOK1 Is Up-Regulated via the c-myc/E2F Transcription Factor Axis in Prostate Cancer.

The atypical protein kinase/ATPase RIO kinase (RIOK)-1 is involved in pre-40S ribosomal subunit production, cell-cycle progression, and protein arginine N-methyltransferase 5 methylosome substrate recruitment. RIOK1 overexpression is a characteristic of several malignancies and is correlated with cancer stage, therapy resistance, poor patient survival, and other prognostic factors. However, its role in prostate cancer (PCa) is unknown. In this study, the expression, regulation, and therapeutic potential of RIOK1 in PCa were examined. RIOK1 mRNA and protein expression were elevated in PCa tissue samples and correlated with proliferative and protein homeostasis-related pathways. RIOK1 was identified as a downstream target gene of the c-myc/E2F transcription factors. Proliferation of PCa cells was significantly reduced with RIOK1 knockdown and overexpression of the dominant-negative RIOK1-D324A mutant. Biochemical inhibition of RIOK1 with toyocamycin led to strong antiproliferative effects in androgen receptor-negative and -positive PCa cell lines with EC50 values of 3.5 to 8.8 nmol/L. Rapid decreases in RIOK1 protein expression and total rRNA content, and a shift in the 28S/18S rRNA ratio, were found with toyocamycin treatment. Apoptosis was induced with toyocamycin treatment at a level similar to that with the chemotherapeutic drug docetaxel used in clinical practice. In summary, the current study indicates that RIOK1 is a part of the MYC oncogene network, and as such, could be considered for future treatment of patients with PCa.

STAT3/LKB1 controls metastatic prostate cancer by regulating mTORC1/CREB pathway.

Prostate cancer (PCa) is a common and fatal type of cancer in men. Metastatic PCa (mPCa) is a major factor contributing to its lethality, although the mechanisms remain poorly understood. PTEN is one of the most frequently deleted genes in mPCa. Here we show a frequent genomic co-deletion of PTEN and STAT3 in liquid biopsies of patients with mPCa. Loss of Stat3 in a Pten-null mouse prostate model leads to a reduction of LKB1/pAMPK with simultaneous activation of mTOR/CREB, resulting in metastatic disease. However, constitutive activation of Stat3 led to high LKB1/pAMPK levels and suppressed mTORC1/CREB pathway, preventing mPCa development. Metformin, one of the most widely prescribed therapeutics against type 2 diabetes, inhibits mTORC1 in liver and requires LKB1 to mediate glucose homeostasis. We find that metformin treatment of STAT3/AR-expressing PCa xenografts resulted in significantly reduced tumor growth accompanied by diminished mTORC1/CREB, AR and PSA levels. PCa xenografts with deletion of STAT3/AR nearly completely abrogated mTORC1/CREB inhibition mediated by metformin. Moreover, metformin treatment of PCa patients with high Gleason grade and type 2 diabetes resulted in undetectable mTORC1 levels and upregulated STAT3 expression. Furthermore, PCa patients with high CREB expression have worse clinical outcomes and a significantly increased risk of PCa relapse and metastatic recurrence. In summary, we have shown that STAT3 controls mPCa via LKB1/pAMPK/mTORC1/CREB signaling, which we have identified as a promising novel downstream target for the treatment of lethal mPCa.

Comprehensive characterization of the prostate tumor microenvironment identifies CXCR4/CXCL12 crosstalk as a novel antiangiogenic therapeutic target in prostate cancer.

BACKGROUND: Crosstalk between neoplastic and stromal cells fosters prostate cancer (PCa) progression and dissemination. Insight in cell-to-cell communication networks provides new therapeutic avenues to mold processes that contribute to PCa tumor microenvironment (TME) alterations. Here we performed a detailed characterization of PCa tumor endothelial cells (TEC) to delineate intercellular crosstalk between TEC and the PCa TME. METHODS: TEC isolated from 67 fresh radical prostatectomy (RP) specimens underwent multi-omic ex vivo characterization as well as orthogonal validation of both TEC functions and key markers by immunohistochemistry (IHC) and immunofluorescence (IF). To identify cell-cell interaction targets in TEC, we performed single-cell RNA sequencing (scRNA-seq) in four PCa patients who underwent a RP to catalogue cellular TME composition. Targets were cross-validated using IHC, publicly available datasets, cell culture expriments as well as a PCa xenograft mouse model. RESULTS: Compared to adjacent normal endothelial cells (NEC) bulk RNA-seq analysis revealed upregulation of genes associated with tumor vasculature, collagen modification and extracellular matrix remodeling in TEC. PTGIR, PLAC9, CXCL12 and VDR were identified as TEC markers and confirmed by IF and IHC in an independent patient cohort. By scRNA-seq we identified 27 cell (sub)types, including endothelial cells (EC) with arterial, venous and immature signatures, as well as angiogenic tip EC. A focused molecular analysis revealed that arterial TEC displayed highest CXCL12 mRNA expression levels when compared to all other TME cell (sub)populations and showed a negative prognostic role. Receptor-ligand interaction analysis predicted interactions between arterial TEC derived CXCL12 and its cognate receptor CXCR4 on angiogenic tip EC. CXCL12 was in vitro and in vivo validated as actionable TEC target by highlighting the vessel number- and density- reducing activity of the CXCR4-inhibitor AMD3100 in murine PCa as well as by inhibition of TEC proliferation and migration in vitro. CONCLUSIONS: Overall, our comprehensive analysis identified novel PCa TEC targets and highlights CXCR4/CXCL12 interaction as a potential novel target to interfere with tumor angiogenesis in PCa.

Amplification of 7p12 Is Associated with Pathologic Nonresponse to Neoadjuvant Chemotherapy in Muscle-Invasive Bladder Cancer.

Pathologic downstaging (pDS) to neoadjuvant chemotherapy (NAC) is one of the most important predictors of survival in muscle-invasive bladder cancer (MIBC). The use of NAC is limited as pDS is only achieved in 30% to 40% of cases and predictive biomarkers are still lacking. We performed a comprehensive immunomolecular biomarker analysis to characterize the role of immune cells and inhibitory checkpoints, genome-wide frequencies of copy number alterations, mutational signatures in whole exome, and tumor mutational burden in predicting NAC response. Our retrospective study included 23 primary MIBC patients who underwent NAC, followed by radical cystectomy. pDS to NAC was a significant prognostic factor for better recurrence-free survival (P < 0.001), with a median time to recurrence of 41.2 versus 5.5 months in nonresponders. DNA damage repair alterations were noticed in 38.1% (n = 8), confirming a positive correlation with high tumor mutational burden (P = 0.007). Chromosomal 7p12 amplification, including the genes HUS1, EGFR, ABCA13, and IKZF1, predicted nonresponse in patients with a sensitivity, a negative predictive value, and a specificity of 71.4%, 87.5%, and 100%, respectively. Total count of CD3+ T cells/mm2 tumor was a significant predictor of NAC response. In conclusion, 7p12 amplification may predict nonresponse to NAC and worse survival in MIBC. Multicenter, prospective trials with sufficient statistical power may further fortify these findings.

Robo 4 - the double-edged sword in prostate cancer: impact on cancer cell aggressiveness and tumor vasculature.

Background: The magic roundabout receptor 4 (Robo 4) is a tumor endothelial marker expressed in the vascular network of various tumor entities. However, the role of Robo 4 in prostate cancer (PCa), the second common cause of cancer death among men in -developed countries, has not been described yet. Thus, the present study investigates for the first time the impact of Robo 4 in PCa both in the clinical setting and in vitro. Methods and Results: Immunohistochemical analyses of benign and malignant prostate tissue samples of 95 PCa patients, who underwent radical prostatectomy (RPE), revealed a significant elevated expression of Robo 4 as well as its ligand Slit 2 protein in cancerous tissue compared to benign. Moreover, increased Robo 4 expression was associated with higher Gleason score and pT stage. In advanced stage we observed a hypothesis-generating trend that high Robo 4 and Slit 2 expression is associated with delayed development of tumor recurrence compared to patients with low Robo 4 and Slit 2 expression, respectively. In contrast to so far described exclusive expression of Robo 4 in the tumor vascular network, our analyses showed that in PCa Robo 4 is not only expressed in the tumor stroma but also in cancer epithelial cells. This finding was also confirmed in vitro as PC3 PCa cells express Robo 4 on mRNA as well as protein level. Overexpression of Robo 4 in PC3 as well as in Robo 4 negative DU145 and LNCaP PCa cells was associated with a significant decrease in cell-proliferation and cell-viability. Conclusion: In summary we observed that Robo 4 plays a considerable role in PCa development as it is expressed in cancer epithelial cells as well as in the surrounding tumor stroma. Moreover, higher histological tumor grade was associated with increased Robo 4 expression; controversially patients with high Robo 4 tend to exert lower biochemical recurrence possibly reflecting a protective role of Robo 4.

Inhibition of Nox4-dependent ROS signaling attenuates prostate fibroblast activation and abrogates stromal-mediated protumorigenic interactions.

Carcinoma-associated fibroblasts (CAFs) play a key onco-supportive role during prostate cancer (PCa) development and progression. We previously reported that the reactive oxygen species (ROS)-producing enzyme NADPH oxidase 4 (Nox4) is essential for TGFß1-mediated activation of primary prostate human fibroblasts to a CAF-like phenotype. This study aimed to further investigate the functional relevance of prostatic Nox4 and determine whether pharmacological inhibition of stromal Nox4 abrogates paracrine-mediated PCa-relevant processes. RNA in situ hybridization revealed significantly elevated Nox4 mRNA levels predominantly in the peri-tumoral stroma of clinical PCa with intense stromal Nox4 staining adjacent to tumor foci expressing abundant TGFß protein levels. At pharmacologically relevant concentrations, the Nox1/Nox4 inhibitor GKT137831 attenuated ROS production, CAF-associated marker expression and migration of TGFß1-activated but not nonactivated primary human prostate fibroblasts. Similar effects were obtained upon shRNA-mediated silencing of Nox4 but not Nox1 indicating that GKT137831 primarily abrogates TGFß1-driven fibroblast activation via Nox4 inhibition. Moreover, inhibiting stromal Nox4 abrogated the enhanced proliferation and migration of PCa cell lines induced by TGFß1-activated prostate fibroblast conditioned media. These effects were not restricted to recombinant TGFß1 as conditioned media from PCa cell lines endogenously secreting high TGFß1 levels induced fibroblast activation in a stromal Nox4- and TGFß receptor-dependent manner. Importantly, GKT137831 also attenuated PCa cell-driven fibroblast activation. Collectively, these findings suggest the TGFß-Nox4 signaling axis is a key interface to dysregulated reciprocal stromal-epithelial interactions in PCa pathophysiology and provide a strong rationale for further investigating the applicability of Nox4 inhibition as a stromal-targeted approach to complement current PCa treatment modalities.

Performance of PI-RADS version 1 versus version 2 regarding the relation with histopathological results.

PURPOSE: Aim of this study was to compare the diagnostic performance of PI-RADS version 1 (v1) and version 2 (v2) in the detection of prostate cancer (PCa). METHODS: Multiparametric MRIs (mpMRI) of 50 consecutive patients with biopsy proven PCa, which had originally been evaluated according to PIRADS v1, were now retrospectively re-evaluated, comparing PI-RADS v1 and v2. MpMRI data were evaluated in comparison with histopathological whole-mount step-section slides. MRI examinations included T2-weighted, diffusion-weighted, and dynamic contrast-enhanced MRI. RESULTS: Overall PI-RADS v1 showed a significantly larger discriminative ability of tumor detection: PI-RADS v1 AUC 0.96 (95 % CI 0.94-0.98) and v2 AUC 0.90 (95 % CI 0.86-0.94). For peripheral zone lesions, PI-RADS v1 showed a significantly larger ability of PCa discrimination: v1 AUC 0.97 (95 % CI 0.95-0.99) and v2 AUC 0.92 (95 % CI 0.88-0.96). For transition zone lesions, PI-RADS v1 showed more discrimination: v1 AUC 0.96 (95 % CI 0.92-1.00) and v2 0.90 (95 % CI 0.83-0.97), but the difference was not significant. PI-RADS v2 resulted in significantly more false negative results (3 % in v1, 14 % in v2) and a comparable number of true positive results (82 % in v1, 80 % in v2). CONCLUSION: PI-RADS v2 uses a simplified approach, but shows a lower diagnostic accuracy. This could lead to a higher rate of false negative results with the risk of missing tumors within low PI-RADS score levels. Therefore, its use cannot be recommended unconditionally, and further improvement should be considered.

Putative Prostate Cancer Risk SNP in an Androgen Receptor-Binding Site of the Melanophilin Gene Illustrates Enrichment of Risk SNPs in Androgen Receptor Target Sites.

Genome-wide association studies have identified genomic loci, whose single-nucleotide polymorphisms (SNPs) predispose to prostate cancer (PCa). However, the mechanisms of most of these variants are largely unknown. We integrated chromatin-immunoprecipitation-coupled sequencing and microarray expression profiling in TMPRSS2-ERG gene rearrangement positive DUCaP cells with the GWAS PCa risk SNPs catalog to identify disease susceptibility SNPs localized within functional androgen receptor-binding sites (ARBSs). Among the 48 GWAS index risk SNPs and 3,917 linked SNPs, 80 were found located in ARBSs. Of these, rs11891426:T>G in an intron of the melanophilin gene (MLPH) was within a novel putative auxiliary AR-binding motif, which is enriched in the neighborhood of canonical androgen-responsive elements. T→G exchange attenuated the transcriptional activity of the ARBS in an AR reporter gene assay. The expression of MLPH in primary prostate tumors was significantly lower in those with the G compared with the T allele and correlated significantly with AR protein. Higher melanophilin level in prostate tissue of patients with a favorable PCa risk profile points out a tumor-suppressive effect. These results unravel a hidden link between AR and a functional putative PCa risk SNP, whose allele alteration affects androgen regulation of its host gene MLPH.

ROS signaling by NADPH oxidase 5 modulates the proliferation and survival of prostate carcinoma cells.

Prostate cancer (PCa) is the most commonly diagnosed cancer and second leading cause of male cancer death in Western nations. Thus, new treatment modalities are urgently needed. Elevated production of reactive oxygen species (ROS) by NADPH oxidase (Nox) enzymes is implicated in tumorigenesis of the prostate and other tissues. However, the identity of the Nox enzyme(s) involved in prostate carcinogenesis remains largely unknown. Analysis of radical prostatectomy tissue samples and benign and malignant prostate epithelial cell lines identified Nox5 as an abundantly expressed Nox isoform. Consistently, immunohistochemical staining of a human PCa tissue microarray revealed distinct Nox5 expression in epithelial cells of benign and malignant prostatic glands. shRNA-mediated knockdown of Nox5 impaired proliferation of Nox5-expressing (PC-3, LNCaP) but not Nox5-negative (DU145) PCa cell lines. Similar effects were observed upon ROS ablation via the antioxidant N-acetylcysteine confirming ROS as the mediators. In addition, Nox5 silencing increased apoptosis of PC-3 cells. Concomitantly, protein kinase C zeta (PKCζ) protein levels and c-Jun N-terminal kinase (JNK) phosphorylation were reduced. Moreover, the effect of Nox5 knockdown on PC-3 cell proliferation could be mimicked by pharmacological inhibition of JNK. Collectively, these data indicate that Nox5 is expressed at functionally relevant levels in the human prostate and clinical PCa. Moreover, findings herein suggest that Nox5-derived ROS and subsequent depletion of PKCζ and JNK inactivation play a critical role in modulating intracellular signaling cascades involved in the proliferation and survival of PCa cells. © 2014 The Authors. Molecular Carcinogenesis published by Wiley Periodicals, Inc.

Evaluation of the 'Prostate Interdisciplinary Communication and Mapping Algorithm for Biopsy and Pathology' (PIC-MABP).

INTRODUCTION: Experience from interdisciplinary cooperation revealed the need for a prostate mapping scheme to communicate multiparametric MRI (mpMRI) findings between radiologists, urologists, and pathologists, which should be detailed, yet easy to memorize. For this purpose, the 'Prostate interdisciplinary communication and mapping algorithm for biopsy and pathology' (PIC-MABP) was developed. This study evaluated the accuracy of the PIC-MABP system. METHODS: PIC-MABP was tested and validated in findings of 10 randomly selected patients from routine clinical practise with 18 histologically proven cancer lesions. Patients received an mpMRI of the prostate prior to prostatectomy. After surgery the prostates were prepared as whole-mount step sections. Cancer lesions, which were found suspicious on mpMRI, were assigned to the according PIC-MABP sectors by a radiologist. MpMRI slides were masked and sent to seven urologists from different centres, providing only the PIC-MABP location of each lesion. Urologists marked the accordant regions. Then mpMRI slides were unmasked, and the correctness of each mark was evaluated. RESULTS: One hundred and seventeen of the 126 marks (93%) were correctly assigned. Detection rates differed for lesions >0.5 cc compared with lesions <0.5 cc (p < 0.005): 3/7 (43%) marks were correctly assigned in lesions <0.3 cc, 16/21 (76%) in lesions with 0.3-0.5 cc, and 98/98 (100%) in lesions >0.5 cc. Interobserver agreement was good for lesions >0.5 cc and poor for lesions <0.3 cc (Fleiss Kappa 1 vs. 0.0175). CONCLUSION: PIC-MABP seems to be a reliable system to communicate the location of mpMRI findings >0.5 cc between different disciplines and can be a useful guidance for cognitive mpMRI/TRUS fusion biopsy.

Low prevalence of HPV detection and genotyping in non-muscle invasive bladder cancer using single-step PCR followed by reverse line blot.

PURPOSE: To clarify the role of human papillomavirus (HPV) in non-muscle invasive bladder cancer, HPV-DNA was scrutinized in formalin-fixed, paraffin-embedded (FFPE) bladder cancer tissue using single-step PCR (HPV L1) for HPV detection, followed by reverse line blot (RLB) for genotyping. METHODS: A total of 186 patients who underwent transurethral resection of the bladder due to primary, non-muscle invasive bladder cancer from 2006 to 2009 were reviewed. A positive control group of 22 cervical tissues with cervical carcinoma was included. RESULTS: Histology confirmed urothelial carcinoma in all patients: primary CIS, pTa, pT1 and pTa + pT1 in 14 (7.5 %), 134 (72 %), 36 (19.4 %) and two (1.1 %) patients, respectively. A total of 119 (63.9 %) of them were classified as low-risk, while 67 (36.1 %) were high-risk cancers. Tumor recurrence and progression (≥pT2) were seen in 79 and 11 patients (mean follow-up 45 months). The presence of HPV-DNA by single-step PCR was detected in four (2.2 %) patients. HPV 16 and HPV 6 were positive in two (1.1 %) and one (0.6 %) patient, respectively In one case, no HPV genotype listed on the RLB assay could be identified. In the control group, the HPV infection rate was 100 %: HPV 16 in 12 (54.6 %) patients, HPV 16/18 in four (18.3 %) patients, HPV 18 in two (9.1 %) patients, HPV 16/45 in one patient (4.5 %), HPV 18/33 in one (4.5 %) patient, HPV 16/33 in one (4.5 %) patient and HPV 33 in one (4.5 %) patient. CONCLUSIONS: Our study demonstrates low prevalence of HPV infection in FFPE bladder cancer tissue, arguing against the etiological role of HPV in non-muscle urothelial carcinogenesis.

Multiparametric magnetic resonance imaging/transrectal ultrasound fusion targeted biopsy of the prostate: preliminary results of a prospective single-centre study.

PURPOSE: To evaluate multiparametric magnetic resonance imaging/transrectal ultrasound (mpMRI/TRUS) fusion targeted biopsy (TB) of the prostate for prostate cancer (PCa) diagnosis. PATIENTS AND METHODS: From April 2013 to January 2014, 53 men were included in this prospective single-centre study. The degree of PCa suspicion from mpMRI findings was classified according to the PI-RADS scoring system. Of these, 50 patients underwent both an mpMRI/TRUS fusion TB and a 10-core systematic biopsy (SB) of the prostate and were eligible for analysis. RESULTS: 225 targeted and 500 systematic cores were included in this study. PCa was histologically confirmed in 52.0% of patients (26/50), whereas TB revealed PCa in 46.0% (23/50) and SB in 36.0% (18/50). TB identified PCa in 16.0% of all patients (8/50) that were missed by SB. All told, the targeted core was 2.8 times more likely to be PCa-positive than the systematic core (29.3 vs. 10.4%). CONCLUSIONS: mpMRI/TRUS fusion TB of the prostate is safe, practicable and may improve PCa diagnosis using fewer biopsy cores compared to SB.

Comparison of real-time elastography and multiparametric MRI for prostate cancer detection: a whole-mount step-section analysis.

OBJECTIVE: The purpose of this study was to compare prostate cancer detection rate of real-time elastography (RTE) with that of multiparametric MRI to evaluate the advantages and disadvantages of the two methods. SUBJECTS AND METHODS: Thirty-nine patients with biopsy-proven prostate cancer underwent both RTE and multiparametric MRI to localize prostate cancer before radical prostatectomy. RTE was performed to assess prostate tissue elasticity, and hard lesions were considered suspicious for prostate cancer. Multiparametric MRI included T2-weighted MRI, diffusion-weighted MRI (DWI), and contrast-enhanced MRI (CE-MRI) with an endorectal coil at 1.5 T. After radical prostatectomy, whole-mount step sections of the prostate were generated, and the prostate cancer detection rates with both modalities were analyzed for cancer lesions measuring 0.2 cm3 or larger. RESULTS: Histopathologic examination revealed 61 cancer lesions. RTE depicted 39 of 50 cancer lesions (78.0%) in the peripheral zone and 2 of 11 (18.2%) in the transitional zone. Multiparametric MRI depicted 45 of 50 cancer lesions (90.0%) in the peripheral zone and 8 of 11 (72.7%) in the transitional zone. Significant differences between the two modalities were found for the transitional zone and anterior part in prostates with volumes greater than 40 cm3 (p<0.05). Detection rates for high-risk prostate cancer (Gleason score≥4 and 3) and cancer lesions with volumes greater than 0.5 cm3 were high for both methods (93.8% and 80.5% for RTE, 87.5% and 92.7% for multiparametric MRI). Volumetric measurements of prostate cancer were more reliable with T2-weighted MRI than with RTE (Spearman rank correlation, 0.72 and 0.46). CONCLUSION: RTE and multiparametric MRI depicted high-risk prostate cancer with high sensitivity. However, multiparametric MRI seems to have advantages in tumor volume assessment and for the detection of prostate cancer in the transitional zone and anterior part within prostates larger than 40 cm3.

Unrecognized paraganglioma of the urinary bladder as a cause for basilar-type migraine.

Extra-adrenal paraganglioma with isolated localization in the urinary bladder is a rare neuroendocrine tumor. Although the typical symptoms like headache, nausea, weight loss, flushing, heart palpitation or paroxysmal hypertension during micturition are well established, we present an unusual case of bladder paraganglioma, 'misdiagnosed' with basilar-type migraine due to headache for the past 8 years. As urologists linked the presence of a tumor (by CT) and symptoms connected with micturition, no cystoscopy and no transurethral resection of the bladder was performed prior to detailed diagnostic workup. After diagnosis of an extra-adrenal paraganglioma, the patient was scheduled for open partial cystectomy. In consideration of the fact that bladder paraganglioma is an infrequent genitourinary cancer, this case report clearly points out the importance of an exact anamnesis and clinical examination to minimize the probability of misdiagnosis with possible fatal consequences in any case with clinical suspicion of bladder paraganglioma.

De novo renal cell carcinoma in a kidney allograft with focus on contrast-enhanced ultrasound.

The development of de novo renal cell carcinoma (RCC) in a transplanted kidney is a rare condition. Currently, this is the second case report of a 41-year-old man in whom carcinoma of a renal allograft was detected by contrast-enhanced ultrasound (CEUS). An abdominal CT scan was not conclusive enough to differentiate between septal enhancement of a cyst and a low vascularized tumor. CEUS confirmed a solid, homogeneously enhancing but hypoechoic and hypovascular lesion compared to the surrounding kidney parenchyma without septal enhancement. Therefore, the patient underwent nephron-sparing surgery (NSS), affirming papillary RCC type 2. Graft function remained unchanged postoperatively; 12 months after NSS, no local recurrence or distant metastasis was described. CEUS seems to be a minimally invasive and efficient imaging option if other diagnostic tools cannot clearly exclude RCC, with the advantage of wide-ranging use, especially in cases of impaired renal function.

Long-term follow up of renal anastomosing hemangioma mimicking renal angiosarcoma.

Anastomosing hemangioma of the kidney is a very rare neoplasm, currently 19 cases have been reported in the literature. First described in 2009, histopathologically anastomosing hemangioma is similar to aggressive angiosarcoma. No long-term follow-up data of anastomosing hemangioma have been described yet. Here, we present the case of a healthy 56-year-old man diagnosed in 2002 with a 7 × 5-cm anastomosing hemangioma mimicking an aggressive renal angiosarcoma. The patient underwent nephrectomy and has been followed up disease free for 13 years.

Glucocorticoid treatment influences prostate cancer cell growth and the tumor microenvironment via altered glucocorticoid receptor signaling in prostate fibroblasts.

Despite significant therapeutic advances in recent years, treatment of metastatic prostate cancer (PCa) remains palliative, owing to the inevitable occurrence of drug resistance. There is increasing evidence that epithelial glucocorticoid receptor (GR) signaling and changes in the tumor-microenvironment (TME) play important roles in this process. Since glucocorticoids (GCs) are used as concomitant medications in the course of PCa treatment, it is essential to investigate the impact of GCs on stromal GR signaling in the TME. Therefore, general GR mRNA and protein expression was assessed in radical prostatectomy specimens and metastatic lesions. Elevated stromal GR signaling after GC treatment resulted in altered GR-target gene, soluble protein expression, and in a morphology change of immortalized and primary isolated cancer-associated fibroblasts (CAFs). Subsequently, these changes affected proliferation, colony formation, and 3D-spheroid growth of multiple epithelial PCa cell models. Altered expression of extra-cellular matrix (ECM) and adhesion-related proteins led to an ECM remodeling. Notably, androgen receptor pathway inhibitor treatments did not affect CAF viability. Our findings demonstrate that GC-mediated elevated GR signaling has a major impact on the CAF secretome and the ECM architecture. GC-treated fibroblasts significantly influence epithelial tumor cell growth and must be considered in future therapeutic strategies.

Comparative analysis of 10X Chromium vs. BD Rhapsody whole transcriptome single-cell sequencing technologies in complex human tissues.

The development of single-cell omics tools has enabled scientists to study the tumor microenvironment (TME) in unprecedented detail. However, each of the different techniques may have its unique strengths and limitations. Here we directly compared two commercially available high-throughput single-cell RNA sequencing (scRNA-seq) technologies - droplet-based 10X Chromium vs. microwell-based BD Rhapsody - using paired samples from patients with localized prostate cancer (PCa) undergoing a radical prostatectomy. Although high technical consistency was observed in unraveling the whole transcriptome, the relative abundance of cell populations differed. Cells with low mRNA content such as T cells were underrepresented in the droplet-based system, at least partly due to lower RNA capture rates. In contrast, microwell-based scRNA-seq recovered less cells of epithelial origin. Moreover, we discovered platform-dependent variabilities in mRNA quantification and cell-type marker annotation. Overall, our study provides important information for selection of the appropriate scRNA-seq platform and for the interpretation of published results.

Metformin Overcomes the Consequences of NKX3.1 Loss to Suppress Prostate Cancer Progression.

BACKGROUND: The antidiabetic drug metformin has known anticancer effects related to its antioxidant activity; however, its clinical benefit for prostate cancer (PCa) has thus far been inconclusive. Here, we investigate whether the efficacy of metformin in PCa is related to the expression status of NKX3.1, a prostate-specific homeobox gene that functions in mitochondria to protect the prostate from aberrant oxidative stress. OBJECTIVE: To investigate the relationship of NKX3.1 expression and metformin efficacy in PCa. DESIGN, SETTING, AND PARTICIPANTS: Functional studies were performed in vivo and in vitro in genetically engineered mouse models and human LNCaP cells, and organotypic cultures having normal or reduced/absent levels of NKX3.1. Correlative studies were performed using two independent retrospective tissue microarray cohorts of radical prostatectomies and a retrospective cohort of prostate biopsies from patients on active surveillance. INTERVENTION: Metformin was administered before or after the induction of oxidative stress by treatment with paraquat. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Functional endpoints included analyses of histopathology, tumorigenicity, and mitochondrial function. Correlative endpoints include Kaplan-Meier curves and Cox proportional hazard regression models. RESULTS AND LIMITATIONS: Metformin reversed the adverse consequences of NKX3.1 deficiency following oxidative stress in vivo and in vitro, as evident by reduced tumorigenicity and restored mitochondrial function. Patients with low NKX3.1 expression showed a significant clinical benefit from taking metformin. CONCLUSIONS: Metformin can overcome the adverse consequences of NKX3.1 loss for PCa progression by protecting against oxidative stress and promoting normal mitochondrial function. These functional activities and clinical correlates were observed only with low NKX3.1 expression. Thus, the clinical benefit of metformin in PCa may depend on the status of NKX3.1 expression. PATIENT SUMMARY: Prostate cancer patients with low NKX3.1 are likely to benefit most from metformin treatment to delay disease progression in a precision interception paradigm.