Johannes Breyer

HIF-1α activation results in actin cytoskeleton reorganization and modulation of Rac-1 signaling in endothelial cells

BackgroundHypoxia is a major driving force in vascularization and vascular remodeling. Pharmacological inhibition of prolyl hydroxylases (PHDs) leads to an oxygen-independent and long-lasting activation of hypoxia-inducible factors (HIFs). Whereas effects of HIF-stabilization on transcriptional responses have been thoroughly investigated in endothelial cells, the molecular details of cytoskeletal changes elicited by PHD-inhibition remain largely unknown. To investigate this important aspect of PHD-inhibition, we used a spheroid-on-matrix cell culture model.ResultsMicrovascular endothelial cells (glEND.2) were organized into spheroids. Migration of cells from the spheroids was quantified and analyzed by immunocytochemistry. The PHD inhibitor dimethyloxalyl glycine (DMOG) induced F-actin stress fiber formation in migrating cells, but only weakly affected microvascular endothelial cells firmly attached in a monolayer. Compared to control spheroids, the residual spheroids were larger upon PHD inhibition and contained more cells with tight VE-cadherin positive cell-cell contacts. Morphological alterations were dependent on stabilization of HIF-1α and not HIF-2α as shown in cells with stable knockdown of HIF-α isoforms. DMOG-treated endothelial cells exhibited a reduction of immunoreactive Rac-1 at the migrating front, concomitant with a diminished Rac-1 activity, whereas total Rac-1 protein remained unchanged. Two chemically distinct Rac-1 inhibitors mimicked the effects of DMOG in terms of F-actin fiber formation and orientation, as well as stabilization of residual spheroids. Furthermore, phosphorylation of p21-activated kinase PAK downstream of Rac-1 was reduced by DMOG in a HIF-1α-dependent manner. Stabilization of cell-cell contacts associated with decreased Rac-1 activity was also confirmed in human umbilical vein endothelial cells.ConclusionsOur data demonstrates that PHD inhibition induces HIF-1α-dependent cytoskeletal remodeling in endothelial cells, which is mediated essentially by a reduction in Rac-1 signaling.

Inhibition of Rho kinases increases directional motility of microvascular endothelial cells

Rho kinases are major regulators of actin cytoskeletal organization and cell motility. Depending on the model system, inhibitors of Rho kinases (ROCK) have been reported to increase or decrease endothelial cell migration. In the present study we investigated the effect of Rho kinase inhibitors on microvascular endothelial cell migration with a special focus on the isoform ROCK2. Migration of microvascular endothelial cells was analyzed in a wound-healing, a spheroid-on-collagen migration assay and in cells embedded in collagen-1 gels. The non-selective Rho kinase inhibitor H1152 was compared to the selective ROCK2 inhibitor SLX2119 and to siRNA knock down. Non-selective inhibition of Rho kinases decreased cell-spanning F-actin fibers, loosened cell-cell contacts visualized by VE cadherin staining, and reduced cell-matrix interactions as shown by reduced Hic-5 expression in focal contacts. Rho kinase inhibitors facilitated directed migration of endothelial cells away from spheroids on fibronectin-coated plates and in collagen-1 gels. By contrast, migration of firmly attached endothelial cells, resembling intact vessels, was not promoted by Rho kinase inhibition. Selective inhibition of ROCK2 mimicked the cytoskeletal effects of H1152 and also increased cell motility, although to a lesser extent. In summary, Rho kinase inhibition enhanced the migration and cytoskeletal restructuring preferentially in freshly attached endothelial cells. ROCK2 may be a potential target to manipulate endothelial cell migration after vessel injury.

Outcome of patients with pathological tumor stage T3 urothelial carcinoma of the bladder following radical cystectomy in a single-center series with 116 patients.

Objective: Outcome prediction of pT3 urothelial carcinoma of the bladder (UCB) after radical cystectomy (RC) remains challenging. The objective of our study was to determine high-risk patients with poor survival outcome in a heterogeneous group substaged pT3 who might profit from early adjuvant chemotherapy. Materials and Methods: We compiled clinicopathological and immunohistochemical data of E-cadherin (E-cad) expression in 116 patients with pT3 UCB after RC in our single-center series. Multivariable Cox regression models including substaged pT3 established clinicopathological features, and the expression of the predictive immunohistochemical feature E-cad was used to identify independent predictors on progression-free (PFS), cancer-specific (CSS) and overall survival (OS), respectively. Results: No significant differences were found addressing clinicopathological data and substaged pT3. In multivariable Cox regression models, lymph node involvement was an independent predictor for PFS (p < 0.001), CSS (p < 0.001) and OS (p = 0.002), respectively. Lymphovascular invasion (LVI) significantly influenced PFS (p = 0.016). ASA score 3/4 independently predicted CSS (p = 0.049) and OS (p = 0.032). Neither pT3 substages nor E-cad expression were significant prognosticators for survival. Conclusions: In pT3 UCB patients with ASA 3/4, positive lymph node status and/or presence of LVI, administration of chemotherapy should be considered due to the high risk of poor oncological outcome. The immunohistochemical marker E-cad was not an independent predictor.

ERBB2 Expression as Potential Risk-Stratification for Early Cystectomy in Patients with pT1 Bladder Cancer and Concomitant Carcinoma in situ

Background/Aims/Objectives: It is difficult to identify patients with a non-muscle-invasive bladder cancer (NMIBC) at stage pT1 with concomitant carcinoma in situ (Cis) who will benefit from an early cystectomy. Methods: We retrospectively analyzed clinical data and formalin-fixed paraffin-embedded tissues of patients with NMIBC. Messenger ribonucleic acid (mRNA) expression of progesterone receptor (PGR), estrogen receptor (ESR1), ERBB2, and marker of proliferation Ki-67 (MKI67) was measured by single-step reverse transcription quantitative real-time polymerase chain reaction using RNA-specific TaqMan assays. Relative gene expression was determined by the normalization of 2 reference genes (CALM2, B2M) using the 40 ΔΔCT method and relative gene expression was correlated to the histopathological stage and oncological outcome. Results: Of 302 patients with pT1 NMIBC in the initial transurethral resection of the bladder, 65 had a concomitant Cis. Elevated ERBB2 expression (>40.1) significantly correlated with progress in patients with and without concomitant Cis (p = 0.020 and p = 0.049, respectively). For the subgroup of pT1 with concomitant Cis, elevated ERBB2 expression significantly discriminated between a high-risk group of 55% progression-free survival (PFS) and a low-risk group of 90% PFS after a 5-year follow-up (p = 0.020). Cox-regression analysis revealed ERBB2 expression as the only independent prognostic factor for PFS (p = 0.0037). Conclusions: High mRNA expression of ERBB2 can identify patients with pT1 NMIBC with concomitant Cis, who have a high risk of progression and might benefit from an early cystectomy.

High Androgen Receptor mRNA Expression Is Independently Associated with Prolonged Cancer-Specific and Recurrence-Free Survival in Stage T1 Bladder Cancer

INTRODUCTION: High-risk non–muscle-invasive bladder cancer (NMIBC) remains challenging given the high probability of progression. Given that the androgen receptor (AR) has been discussed as a possible factor in the development and progression of bladder cancer, we investigated the predictive value of AR in stage pT1 NMIBC. MATERIALS AND METHODS: We retrospectively analyzed the clinical data and AR mRNA expression in 296 patients with stage pT1 NMIBC who underwent a transurethral resection of the bladder. The mRNA expression of the AR transcript variants 1 (AR1) and 2 (AR2) was measured by reverse transcription quantitative real-time polymerase chain reaction. AR expression was also correlated to KRT5 and KRT20 mRNA expression. RESULTS: Kaplan-Meier analysis indicated that high AR1 mRNA expression ≥35.47 is associated with statistically significant better recurrence-free survival (RFS) (P = .0007), progression-free survival (PFS) (P = .0420), and cancer-specific survival (CSS) (P = .0050). Multivariate Cox regression analysis revealed that high AR1 mRNA expression is an independent prognostic marker for RFS (P = .0029) and CSS (P = .0119). Spearman rank correlation revealed a significant positive association between mRNA expression of AR1 and KRT5 (rs: 0.3171, P < .0001) as well as a negative association with multifocal tumors (rs: 0.1478, P < .0109). No association was noted between AR1 expression and tumor grade, concomitant CIS, gender, tumor size, and KRT20 in patients with stage T1 NMIBC. CONCLUSIONS: AR mRNA expression can predict RFS and CSS in patients with stage T1 NMIBC. Further studies are necessary to refine the relevance of AR mRNA expression compared with immunohistochemically detectable AR expression.

Predictive value of molecular subtyping in NMIBC by RT-qPCR of ERBB2, ESR1, PGR and MKI67 from formalin fixed TUR biopsies

Expression of ESR1, PGR, HER2 and Ki67 is important for risk stratification and therapy in breast cancer. Hormone receptor expression can also be found in MIBC, reflecting luminal and basal subtypes of breast cancer. Thus the purpose was to investigate on the mRNA expression of the aforementioned markers and their prognostic value in pT1 bladder cancer. Retrospective analysis of clinical data and Formalin-Fixed Paraffin-Embedded tissues (FFPE) of patients with stage pT1 NMIBC who underwent transurethral resection of the bladder was performed. mRNA expression was measured by single step RT-qPCR. Relative gene expression was determined by normalization to two housekeeping genes (CALM2, B2M) using the 40-ΔΔCT method. Correlation of mRNA expression with outcome was assessed using Kaplan-Meier analysis and multivariate Cox regression analysis. From overall 302 patients, 255 samples could be analyzed with valid measurements. Subtype distribution was Luminal-A in 11.4%, Luminal-B in 38.8%, triple negative in 36.9% and ERBB2 in 12.9%, respectively. Kaplan-Meier analysis revealed molecular subtyping being statistical significant for RFS (p=0.0408) and PFS (p=0.0039). Luminal-A patients did have the best RFS and PFS. Multivariate analysis revealed molecular subtyping to be significant for PFS (L-R Chi2 of 11.89, p=0.0078). Elevated expression of HER2 was statistically significant for PFS (p=0.0025) and discriminated among G3 tumors a high risk group (60% PFS) from a low risk risk group (90% PFS) after 5 year follow-up (p<0.001). Expression of ESR1, PGR and HER2 has predictive value in stage pT1 NMIBC and reveals potential therapeutic targets.Expression of ESR1, PGR, HER2 and Ki67 is important for risk stratification and therapy in breast cancer. Hormone receptor expression can also be found in MIBC, reflecting luminal and basal subtypes of breast cancer. Thus the purpose was to investigate on the mRNA expression of the aforementioned markers and their prognostic value in pT1 bladder cancer. Retrospective analysis of clinical data and Formalin-Fixed Paraffin-Embedded tissues (FFPE) of patients with stage pT1 NMIBC who underwent transurethral resection of the bladder was performed. mRNA expression was measured by single step RT-qPCR. Relative gene expression was determined by normalization to two housekeeping genes (CALM2, B2M) using the 40-ΔΔCT method. Correlation of mRNA expression with outcome was assessed using Kaplan-Meier analysis and multivariate Cox regression analysis. From overall 302 patients, 255 samples could be analyzed with valid measurements. Subtype distribution was Luminal-A in 11.4%, Luminal-B in 38.8%, triple negative in 36.9% and ERBB2 in 12.9%, respectively. Kaplan-Meier analysis revealed molecular subtyping being statistical significant for RFS (p=0.0408) and PFS (p=0.0039). Luminal-A patients did have the best RFS and PFS. Multivariate analysis revealed molecular subtyping to be significant for PFS (L-R Chi2 of 11.89, p=0.0078). Elevated expression of HER2 was statistically significant for PFS (p=0.0025) and discriminated among G3 tumors a high risk group (60% PFS) from a low risk risk group (90% PFS) after 5 year follow-up (p<0.001). Expression of ESR1, PGR and HER2 has predictive value in stage pT1 NMIBC and reveals potential therapeutic targets.

FOXM1 predicts overall and disease specific survival in muscle-invasive urothelial carcinoma and presents a differential expression between bladder cancer subtypes

Forkhead box M1 (FOXM1) is a late cell cycle gene that plays a crucial role in carcinogenesis and chemotherapeutic drug resistance. In this study, the impact of FOXM1 expression on patient outcome was investigated for the first time in formalin fixed and paraffin embedded (FFPE) samples of chemotherapy naïve muscle-invasive bladder cancer (MIBC) patients. Expression analyses were performed on the Mannheim cohort (n=84) and validated on the independent Chungbuk cohort (n=61). In a Cox’ proportional hazards model, a distinct FOXM1 expression cut-off dividing both cohorts in a ‘high-risk’ and ‘low-risk’ group has been determined. Multivariate analyses showed that FOXM1 is an independent risk factor for outcome prediction superior to the TNM system. The FOXM1 ‘high-risk’ group had a 4- to 7-fold increased risk of death (p<0.03) and presented further an overexpression of MKI67. Recent studies showed that MIBCs can be subclassified in breast cancer-like subtypes: basal, luminal and p53-like. Here we demonstrated that FOXM1 was differentially expressed between MIBC subtypes concordant to its subtype specific expression in breast cancer. Since the proto-oncogene FOXM1 is known to play an important role in cisplatin resistance and to be a promising drug target, this study supports FOXM1 as a crucial biomarker in the personalization of MIBC therapy and urges prospective translational studies.

Prognostic Value of Molecular Breast Cancer Subtypes based on Her2, ESR1, PGR and Ki67 mRNA-Expression in Muscle Invasive Bladder Cancer

INTRODUCTION: Gene expression analyses have identified similarities between bladder and breast cancer, where clinical risk stratification is based on Her2, ESR1, PGR and Ki67 expression. The aim of the study was to assess the respective marker gene expression in patients treated with radical cystectomy for muscle-invasive bladder cancer (MIBC) and to evaluate the applicability of breast cancer subtypes for MIBC risk stratification. MATERIALS & METHODS: 102 patients treated with radical cystectomy for MIBC were assessed. Using routine FFPE tissue and an IVD validated kit, mRNA expression was measured by single step RT-qPCR. Partition test were employed to define cut-off values for high or low marker gene expression. Association of expression with outcome was assessed using Kaplan-Meier analysis and multivariate cox regression analysis. Finally, we performed validation of our results in the MD-Anderson cohort (n = 57). RESULTS: Cancer specific survival (CSS) was impaired in patients with high gene expression of Her2 (P = 0.0009) and ESR1 (P = 0.04). In the multivariate regression model Her2 expression remained significant for the prediction of CSS (HR = 2.11, CI 1.11-4.21, P = 0.024). Furthermore, molecular stratification by breast cancer subgroups was significant (P = 0.023) for CSS prediction. Especially the differentiation between Her2-positive and Luminal A (HR = 4.41, CI 1.53-18.71, P = 0.004) and Luminal B (HR = 1.96, CI 0.99-4.08, P = 0.053) respectively was an independent prognostic parameter for CSS. External validation resulted in comparable risk stratification with differences in fractional subgroups distribution. CONCLUSION: Gene expression of Her2, ESR1, PGR, Ki67 and corresponding breast cancer subtypes allow a risk-stratification in MIBC, whereby Her2 overexpressing tumors reveal a particularly poor prognosis.

A multicenter round robin test of PD-L1 expression assessment in urothelial bladder cancer by immunohistochemistry and RT-qPCR with emphasis on prognosis prediction after radical cystectomy

Background Immunohistochemical PD-L1 assessment is currently used to identify responders towards checkpoint inhibitors although it is limited by inter-observer effects. Here, we conducted a multi-center round robin test to prove the possibility of assessing the PD-L1 status by gene expression to avoid inter-observer effects. Patients and methods Gene expression of PD-L1 was analyzed in a total of 294 samples (14 cases non-muscle invasive and muscle-invasive bladder cancer; MIBC) in seven centers by a RT-qPCR kit and compared with immunohistochemical scoring of three pathologists (DAKO, 22c3). Both assays were compared towards prognosis prediction in a cohort of 88 patients with MIBC. Results PD-L1 gene expression revealed very high inter center correlation (centrally extracted RNA: r = 0.68–0.98, p ≤ 0.0076; locally extracted RNA: r = 0.81–0.98, p ≤ 0.0014). IHC Inter-observer concordance was moderate to substantial for immune cells (IC), fair for combined IC/ tumor cell (TC) (IC: κ = 0.50–0.61; IC + TC: κ = 0.50), and fair for TC scoring (κ = 0.26–0.35). Gene expression assessment resulted in more positive cases (9/14 cases positive vs. 6/14 cases [IHC]) which could be validated in the independent cohort. Positive mRNA status was associated with significantly better overall and disease-specific survival (5-year OS: 50% vs. 26%, p = 0.0042, HR = 0.48; 5 year DSS: 65% vs. 40%, p = 0.012, HR = 0.49). The 1% IHC IC cut-off also revealed significant better OS (5 year OS: 58% vs. 31%, p = 0.036, HR = 0.62). Conclusion Gene expression showed very high inter-center agreement. Gene expression assessment also resulted in more positive cases and revealed better prognosis prediction. PD-L1 mRNA expression seems to be a reproducible and robust tool for PD-L1 assessment.

High CDKN2A/p16 and Low FGFR3 Expression Predict Progressive Potential of Stage pT1 Urothelial Bladder Carcinoma

Micro‐Abstract Identifying pT1 bladder cancer with high risk for progression remains a challenge. Aberrations in cyclin‐dependent kinase inhibitor 2A (CDKN2A)/p16 and fibroblast growth factor receptor 3 (FGFR3) expression are the most common in urothelial bladder cancer. In the study at hand, we could show that high CDKN2A/p16 mRNA expression is associated with the luminal subtype and high CDKN2A/p16 as well as low FGFR3 mRNA expression are associated with worse progression‐free survival. Background: A recent study on the comprehensive genomic profile of advanced urothelial bladder cancer (UBC) showed cyclin‐dependent kinase inhibitor 2A (CDKN2A) and fibroblast growth factor receptor 3 (FGFR3) as the most often clinically relevant genomic alterations. Therefore, the prognostic role of FGFR3 and CDKN2A/p16 for pT1 UBC was studied. Patients and Methods: Clinical data and formalin‐fixed paraffin‐embedded tissues of pT1 UBC treated with an organ‐preserving approach was analyzed retrospectively. Total RNA was isolated using commercial RNA extraction kits and mRNA expression of CDKN2A/p16 and FGFR3 was measured using single step reverse transcription quantitative real time polymerase chain reaction using RNA‐specific TaqMan assays. Results: Data from 296 patients (79.4% male; median age: 72 years) could be used for the final evaluation. Spearman correlation revealed a statistically significant negative correlation between mRNA expression of CDKN2A/p16 and FGFR3. There was a positive correlation between CDKN2A/p16 and G3 tumors (&rgr; = 0.1875; P = .0012) and associated carcinoma in situ (&rgr; = 0.1703, P = .0033) and a negative correlation between FGFR3 and these factors (&rgr; = −0.2791, P < .0001 and &rgr; = −0.2182, P = .0002). High CDKN2A/p16 expression (≥38.04) and low FGFR3 expression (<39.14) were statistically significantly associated with worse progression‐free survival (PFS; P = .0194 and P = .0089). Multivariate Cox regression analysis could identify patients with low FGFR3 and high CDKN2A/p16 expression (log rank (LR) χ2 = 10.69; P = .0048) as well as tumor size ≥3 cm (LR χ2 = 6.03; P = .0141) as independent predictors for PFS. Conclusion: High expression of CDKN2A/p16 and low expression of FGFR3 show a correlation with established prognostic features for non–muscle‐invasive bladder cancer and can predict progression of stage pT1 UBC.