Nivolumab + Ipilimumab as Immunotherapeutic Boost in Metastatic Urothelial Carcinoma: A Nonrandomized Clinical Trial

Importance

Studies with nivolumab, an approved therapy for metastatic urothelial carcinoma (mUC) after platinum-based chemotherapy, demonstrate improved outcomes with added high-dose ipilimumab.

Objective

To assess efficacy and safety of a tailored approach using nivolumab + ipilimumab as an immunotherapeutic boost for mUC.

Design, Setting, and Participants

In this phase 2 nonrandomized trial, patients with mUC composed 2 cohorts. Cohort 1 received first-line or second-/third-line nivolumab with escalating doses of ipilimumab, and cohort 2 received second-/third-line nivolumab with high-dose ipilimumab. Recruitment spanned 26 sites in Germany and Austria from August 8, 2017, to February 18, 2021. All patients had a 70% or higher Karnofsky Performance Score and measurable disease per Response Evaluation Criteria in Solid Tumours, version 1.1.

Interventions

All patients initiated 4 doses of 240-mg nivolumab (1× every 2 wk). Week 8 nonresponders received nivolumab + ipilimumab (1× every 3 wk). Cohort 1 received 2 doses of 3-mg/kg nivolumab + 1-mg/kg ipilimumab followed by 2 doses of 1-mg/kg nivolumab + 3-mg/kg ipilimumab if no response. Due to safety concerns, cohort 1 treatment was halted, and first-line cohort 2 treatment was not pursued. Cohort 2 received 2 to 4 doses of 1-mg/kg nivolumab + 3-mg/kg ipilimumab. Responders continued with nivolumab maintenance but could receive nivolumab + ipilimumab for later progression.

Main Outcomes and Measures

The primary end point was objective response rate.

Results

The study comprised 169 patients (118 [69.8%] men; median [range] age, 68 [37-84] years): 86 in cohort 1 (42 first-line; 44 second-/third-line) and 83 in cohort 2. The median (IQR) follow-up times were 10.4 (4.2-23.5) months (first-line cohort 1), 7.5 (3.1-23.8) months (second-/third-line cohort 1), and 6.2 (3.2-22.7) months (cohort 2). Response rates to nivolumab induction were 12/42 (29%, first-line cohort 1), 10/44 (23%, second-/third-line cohort 1), and 17/83 (20%, cohort 2). Response rates to a tailored approach were 20/42 (48% [90% CI, 34%-61%], first-line cohort 1), 12/44 (27% [90% CI, 17%-40%], second-/third-line cohort 1), and 27/83 (33% [90% CI, 23%-42%], cohort 2). Three-year overall survival rates for first-line cohort 1, second-/third-line cohort 1, and cohort 2 using the Kaplan-Meier method were 32% (95% CI, 17%-49%), 19% (95% CI, 8%-33%), and 34% (95% CI, 23%-44%), respectively.

Conclusions and Relevance

In this nonrandomized trial, although first-line cohort 1 treatment improved objective response rates, considerable progression events urge caution with this as a first-line therapy. Second-/third-line cohort 1 treatment did not improve response rates compared with nivolumab monotherapy. However, added high-dose ipilimumab may improve tumor response and survival in patients with mUC.

Trial Registration

ClinicalTrials.gov Identifier: NCT03219775.

Die EU-Verordnung für In-vitro-Diagnostika (IVDR) in der Praxis: Umsetzung und Anwendung - Ergebnisse einer öffentlichen Veranstaltung der Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften (AWMF) im März 2023

In order to discuss first experiences with the implementation of the EU Regulation on In Vitro Diagnostic Medical Devices (IVDR) about one year after its entry into force, the German Association of the Scientific Medical Societies (AWMF e.V.) organized a full-day public webinar. Overall, it became clear that the implementation of the IVDR still poses significant challenges for laboratory medicine and pathology. Corrections at the political level and implementation with a sense of proportion are required. Before the long-term goal of the IVDR, i.e. the increase in patient safety, can be realized, the prevention of disadvantages for patients due to gaps in care must be strived for in the medium term by all parties involved.

Non-invasive medical gas plasma augments bladder cancer cell toxicity in preclinical models and patient-derived tumor tissues

INTRODUCTION

Medical gas plasma therapy has been successfully applied to several types of cancer in preclinical models. First palliative tumor patients suffering from advanced head and neck cancer benefited from this novel therapeutic modality. The gas plasma-induced biological effects of reactive oxygen and nitrogen species (ROS/RNS) generated in the plasma gas phase result in oxidation-induced lethal damage to tumor cells.

OBJECTIVES

This study aimed to verify these anti-tumor effects of gas plasma exposure on urinary bladder cancer.

METHODS

2D cell culture models, 3D tumor spheroids, 3D vascularized tumors grown on the chicken chorion-allantois-membrane (CAM) in ovo, and patient-derived primary cancer tissue gas plasma-treated ex vivo were used.

RESULTS

Gas plasma treatment led to oxidation, growth retardation, motility inhibition, and cell death in 2D and 3D tumor models. A marked decline in tumor growth was also observed in the tumors grown in ovo. In addition, results of gas plasma treatment on primary urothelial carcinoma tissues ex vivo highlighted the selective tumor-toxic effects as non-malignant tissue exposed to gas plasma was less affected. Whole-transcriptome gene expression analysis revealed downregulation of tumor-promoting fibroblast growth factor receptor 3 (FGFR3) accompanied by upregulation of apoptosis-inducing factor 2 (AIFm2), which plays a central role in caspase-independent cell death signaling.

CONCLUSION

Gas plasma treatment induced cytotoxicity in patient-derived cancer tissue and slowed tumor growth in an organoid model of urinary bladder carcinoma, along with less severe effects in non-malignant tissues. Studies on the potential clinical benefits of this local and safe ROS therapy are awaited.

Tailored Immunotherapy Approach With Nivolumab in Advanced Transitional Cell Carcinoma

PURPOSE

Several anti-programmed cell death (ligand)-1 (PD-[L]1) immune checkpoint inhibitors are approved in advanced/metastatic urothelial carcinoma (mUC). Recently, improved activity of an anti-PD-1/anticytotoxic T-cell lymphocyte-4 (CTLA-4) combination versus anti-PD-1 monotherapy has been reported. We report a response-based approach starting treatment with nivolumab monotherapy with nivolumab/ipilimumab as immunotherapeutic boost.

METHODS

After four doses of nivolumab induction, responders continued with nivolumab maintenance therapy. Patients with stable/progressive disease received nivolumab 3 mg/kg plus ipilimumab 1 mg/kg once every 3 weeks for 2 doses followed by nivolumab 1 mg/kg plus ipilimumab 3 mg/kg once every 3 weeks for 2 doses, if not responding to the initial boost. Responders to boosts continued with nivolumab maintenance. Between July 2017 and April 2019, 86 patients were enrolled. The median follow-up is 7.7 months. The primary end point is objective response rate (ORR) per RECIST1.1. Secondary end points include efficacy of nivolumab induction, remission rate with nivolumab/ipilimumab boosts, overall survival, and safety.

RESULTS

Of all patients, 42, 39, and five were first- (1L), second- (2L), and third-line (3L), respectively. The median age was 68 years. The ORR with nivolumab monotherapy (assessed at week 8) was 29% in 1L and 23% in 2/3L, respectively. Forty-one patients received early (week 8) and 11 received later nivolumab/ipilimumab boosts. ORRs with nivolumab with or without nivolumab/ipilimumab (best overall response) were 45% and 27% in 1L and 2/3L, respectively. In 1L, 7 of 17 patients receiving boosts at week 8 improved, compared with 2 of 24 in 2/3L.

CONCLUSION

The tailored approach of TITAN-TCC shows meaningful clinical activity supporting dual checkpoint inhibition in 1L mUC. However, starting therapy with nivolumab exclusively appears inadequate given the aggressive nature of mUC. In 2/3L, nivolumab/ipilimumab boosts with escalating ipilimumab dose did not improve efficacy outcomes versus nivolumab monotherapy. An independent 2L cohort of TITAN-TCC receiving nivolumab 1 mg/kg plus ipilimumab 3 mg/kg once every 3 weeks for 4 doses is ongoing.

ScoMorphoFISH: A deep learning enabled toolbox for single-cell single-mRNA quantification and correlative (ultra-)morphometry

Increasing the information depth of single kidney biopsies can improve diagnostic precision, personalized medicine and accelerate basic kidney research. Until now, information on mRNA abundance and morphologic analysis has been obtained from different samples, missing out on the spatial context and single‐cell correlation of findings. Herein, we present scoMorphoFISH, a modular toolbox to obtain spatial single‐cell single‐mRNA expression data from routinely generated kidney biopsies. Deep learning was used to virtually dissect tissue sections in tissue compartments and cell types to which single‐cell expression data were assigned. Furthermore, we show correlative and spatial single‐cell expression quantification with super‐resolved podocyte foot process morphometry. In contrast to bulk analysis methods, this approach will help to identify local transcription changes even in less frequent kidney cell types on a spatial single‐cell level with single‐mRNA resolution. Using this method, we demonstrate that ACE2 can be locally upregulated in podocytes upon injury. In a patient suffering from COVID‐19‐associated collapsing FSGS, ACE2 expression levels were correlated with intracellular SARS‐CoV‐2 abundance. As this method performs well with standard formalin‐fixed paraffin‐embedded samples and we provide pretrained deep learning networks embedded in a comprehensive image analysis workflow, this method can be applied immediately in a variety of settings.

Efficacy and safety of erdafitinib in patients with locally advanced or metastatic urothelial carcinoma: long-term follow-up of a phase 2 study

BACKGROUND

Erdafitinib, a pan-fibroblast growth factor receptor (FGFR) tyrosine kinase inhibitor, was shown to be clinically active and tolerable in patients with advanced urothelial carcinoma and prespecified FGFR alterations in the primary analysis of the BLC2001 study at median 11 months of follow-up. We aimed to assess the long-term efficacy and safety of the selected regimen of erdafitinib determined in the initial part of the study.

METHODS

The open-label, non-comparator, phase 2, BLC2001 study was done at 126 medical centres in 14 countries across Asia, Europe, and North America. Eligible patients were aged 18 years or older with locally advanced and unresectable or metastatic urothelial carcinoma, at least one prespecified FGFR alteration, an Eastern Cooperative Oncology Group performance status of 0-2, and progressive disease after receiving at least one systemic chemotherapy or within 12 months of neoadjuvant or adjuvant chemotherapy or were ineligible for cisplatin. The selected regimen determined in the initial part of the study was continuous once daily 8 mg/day oral erdafitinib in 28-day cycles, with provision for pharmacodynamically guided uptitration to 9 mg/day (8 mg/day UpT). The primary endpoint was investigator-assessed confirmed objective response rate according to Response Evaluation Criteria In Solid Tumors version 1.1. Efficacy and safety were analysed in all treated patients who received at least one dose of erdafitinib. This is the final analysis of this study. This study is registered with ClinicalTrials.gov, NCT02365597.

FINDINGS

Between May 25, 2015, and Aug 9, 2018, 2328 patients were screened, of whom 212 were enrolled and 101 were treated with the selected erdafitinib 8 mg/day UpT regimen. The data cutoff date for this analysis was Aug 9, 2019. Median efficacy follow-up was 24·0 months (IQR 22·7-26·6). The investigator-assessed objective response rate for patients treated with the selected erdafitinib regimen was 40 (40%; 95% CI 30-49) of 101 patients. The safety profile remained similar to that in the primary analysis, with no new safety signals reported with longer follow-up. Grade 3-4 treatment-emergent adverse events of any causality occurred in 72 (71%) of 101 patients. The most common grade 3-4 treatment-emergent adverse events of any cause were stomatitis (in 14 [14%] of 101 patients) and hyponatraemia (in 11 [11%]). There were no treatment-related deaths.

INTERPRETATION

With longer follow-up, treatment with the selected regimen of erdafitinib showed consistent activity and a manageable safety profile in patients with locally advanced or metastatic urothelial carcinoma and prespecified FGFR alterations.

FUNDING

Janssen Research & Development.

Gelsolin Governs the Neuroendocrine Transdifferentiation of Prostate Cancer Cells and Suppresses the Apoptotic Machinery

BACKGROUND/AIM

Interleukin 6 (IL6) is increased in patients with progressive prostate cancer and induces its transdifferentiation to neuroendocrine prostate cancer. Neuroendocrine prostate cancer has become one of the greatest challenges in treating castration-resistant disease and is linked to poor prognosis. It is necessary to understand better the cellular events associated with IL6-mediated neuroendocrine differentiation to prevent it and identify potential new therapeutic targets.

MATERIALS AND METHODS

In the present study, an IL6-inducible neuroendocrine differentiation model established specifically for this purpose was applied using LNCaP cells. Proteomics and western blot analyses were used to identify proteins involved in neuroendocrine differentiation. Subsequently, the role of gelsolin (GSN) in the neuroendocrine differentiation model was characterized (knock-down analyses, microscopic co-localization analyses, apoptosis assay) and GSN expression levels in patient material were investigated.

RESULTS

This study revealed that GSN is a crucial factor in the neuroendocrine differentiation process.

CONCLUSION

It was shown that siRNA-mediated knock-down of GSN can inhibit neuroendocrine differentiation, making it a valid target for preventing IL6-mediated neuroendocrine differentiation.

Super-resolved local recruitment of CLDN5 to filtration slits implicates a direct relationship with podocyte foot process effacement

Under healthy conditions, foot processes of neighbouring podocytes are interdigitating and connected by an electron‐dense slit diaphragm. Besides slit diaphragm proteins, typical adherens junction proteins are also found to be expressed at this cell‐cell junction. It is therefore considered as a highly specialized type of adherens junction. During podocyte injury, podocyte foot processes lose their characteristic 3D structure and the filtration slits typical meandering structure gets linearized. It is still under debate how this change of structure leads to the phenomenon of proteinuria. Using super‐resolution 3D‐structured illumination microscopy, we observed a spatially restricted up‐regulation of the tight junction protein claudin‐5 (CLDN5) in areas where podocyte processes of patients suffering from minimal change disease (MCD), focal and segmental glomerulosclerosis (FSGS) as well as in murine nephrotoxic serum (NTS) nephritis and uninephrectomy DOCA‐salt hypertension models, were locally injured. CLDN5/nephrin ratios in human glomerulopathies and NTS‐treated mice were significantly higher compared to controls. In patients, the CLDN5/nephrin ratio is significantly correlated with the filtration slit density as a foot process effacement marker, confirming a direct association of local CLDN5 up‐regulation in injured foot processes. Moreover, CLDN5 up‐regulation was observed in some areas of high filtration slit density, suggesting that CLND5 up‐regulation preceded the changes of foot processes. Therefore, CLDN5 could serve as a biomarker predicting early foot process effacement.

FC 017DEEP-LEARNING ENABLED QUANTIFICATION OF SINGLE-CELL SINGLE-MRNA TRANSCRIPTS AND CORRELATIVE SUPER-RESOLVED PODOCYTE FOOT PROCESS MORPHOMETRY IN ROUTINE KIDNEY BIOPSY SPECIMEN

Background and Aims

Although high-throughput single-cell transcriptomic analysis, super-resolution light microscopy and deep-learning methods are broadly used, the gold-standard to evaluate kidney biopsies is still the histologic assessment of formalin-fixed and paraffin embedded (FFPE) samples with parallel ultrastructural evaluation. Recently, we and others have shown that super-resolution fluorescence microscopy can be used to study glomerular ultrastructure in human biopsy samples. Additionally, in the last years mRNA in situ hybridization techniques have been improved to increase specificity and sensitivity to enable transcriptomic analysis with single-mRNA resolution (smFISH).

Method

For smFISH, we used the fluorescent multiplex RNAscope kit with probes targeting ACE2, WT1, PPIB, UBC and POLR2A. To find an on-slide reference gene, the normfinder algorithm was used. The smFISH protocol was combined with a single-step anti-podocin immunofluorescence enabled by VHH nanobodies. Podocytes were labeled by tyramide-signal amplified immunofluorescence using recombinant anti-WT1 antibodies. Slides were imaged using confocal laser scanning, as well as 3D structured illumination microscopy. Deep-learning networks to segment glomeruli and cell nuclei (UNet and StarDist) were trained using the ZeroCostDL4Mic approach. Scripts to automate analysis were developed in the ImageJ1 macro language.

Results

First, we show robust functionality of threeplex smFISH in archived routine FFPE kidney biopsy samples with single-mRNA resolution. As variations in sample preparation can negatively influence mRNA-abundance, we established PPIB as an ideal on-slide reference gene to account for different RNA-integrities present in biopsy samples. PPIB was chosen for its most stable expression in microarray dataset of various glomerular diseases determined by the Normfinder algorithm as well as its smFISH performance.

To segment glomeruli and to label glomerular and tubulointerstitial cell subsets, we established a combination of smFISH and immunofluorescence. As smFISH requires intense tissue digestion to liberate cross-linked RNAs, immunofluorescence protocols had to be adapted: For podocin, a small-sized single-step label approach enabled by small nanobodies and for WT1, tyramide signal amplification was used.

For enhanced segmentation performance, we used deep learning: First, a network was customized to recognize DAPI+ cell nuclei and WT1/DAPI+ podocyte nuclei. Second, a UNet was trained to segment glomeruli in podocin-stained tissue sections. Using these segmentation masks, we could annotate PPIB-normalized single mRNA transcripts to individual cells. We established an ImageJ script to automatize transcript quantification.

As a proof-of-principle, we demonstrate inverse expression of WT1 and ACE2 in glomerular vs. tubulointerstitial single cells. Furthermore, in the podocyte subset, WT1 highly clustered whereas no significant ACE2 expression was found under baseline conditions.

Additionally, when imaged with super-resolution microscopy, podocyte filtration slit morphology could be visualized The optical resolution was around 125 nm and therefore small enough to resolve individual foot processes. The filtration slit density as a podocyte-integrity marker did not differ significantly from undigested tissue sections proving the suitability for correlative podocyte foot process morphometry with single-podocyte transcript analysis.

Conclusion

Here we present a modular toolbox which combines algorithms for multiplexed, normalized single-cell gene expression with single mRNA resolution in cellular subsets (glomerular, tubulointerstitial and podocytes). Additionally, this approach enables correlation with podocyte filtration slit ultrastructure and gross glomerular morphometry.

Tailored immunotherapy approach with nivolumab in advanced transitional cell carcinoma (TITAN-TCC)

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Background: Several PD-1 immune-checkpoint inhibitors including Nivolumab (Nivo) are approved in urothelial cancer. Recently, in the front line setting, improved activity of combined PD-L1 and CTLA4 immune-checkpoint inhibition has been reported and a phase III trial with Nivolumab + Ipilimumab (Nivo+Ipi) is ongoing. Here we report a response-based tailored approach starting treatment with Nivo monotherapy using Nivo+Ipi as immunotherapeutic “boost”. Methods: Between July 2017 and April 2019 86 patients were enrolled and treated according to protocol version 3 (cohort 1). Patients started with Nivo 240 mg Q2W induction. After 4 dosings and tumor assessment at week 8 (i) responders (PR/CR) to Nivo monotherapy continued with maintenance while (ii) patients with stable (SD) or progressive disease (PD) received 2 cycles Nivo3+Ipi1 followed by another 2 cycles Nivo1+Ipi3 if not responding. Median follow-up is 8.7 months. The primary endpoint is confirmed investigator-assessed objective response rate (ORR) per RECIST1.1. Secondary endpoints include activity of Nivo monotherapy at week 8, remission rate with Nivo+Ipi “boosts”, safety, overall survival and quality of life. Results: Of the patients 42, 39 and 5 were first, second and third line, respectively. Median age was 67 years (range 45-84), 61 patients (71 %) were male and 25 female. ORR with Nivo monotherapy at first assessment (week 8) was 29 % and 23 % in first and second/third line, respectively. Of the patients 41 received Nivo+Ipi “boosts” after week 8 while 12 received later “boosts”. Best overall response (BOR) rate with Nivo induction ± Nivo+Ipi “boosts” was 48 % and 27 % in first and second/third line, respectively. In first line 7/17 (41 %) patients receiving Nivo+Ipi after week 8 had an improved response compared to 2/24 (8.3 %) in second/third line. Of the patients who continued with Nivo maintenance after week 8 and received later “boosts” 2/12 (17 %) had a PR and 2/12 (17 %) improved to SD. Treatment-related AEs will be presented. Conclusions: TITAN–TCC explores a response-driven use of Nivo+Ipi as an immunotherapeutic “boost”. In first line, this significantly improved ORR compared to the expected response rate of Nivo monotherapy, providing further evidence to the added value of Ipi in combination with Nivo. Further follow-up is ongoing to characterize duration and depth of response. Clinical trial information: NCT03219775 . Research Sponsor: Bristol-Myers Squibb[Table: see text]

BK virus-induced nephritis and cystitis after matched unrelated donor stem cell transplantation: A case report

Currently, there is no standard therapy for a BK virus infection of the urogenital tract in immunocompromised, stem cell transplanted patients, so that early diagnosis and introduction of supportive measures have the highest response rates to date.

Standardization in biobanking – between cooperation and competition

This article presents the current situation of German biobanks and shows future fields of action in the European and international context on the basis of upcoming legal and normative challenges. It gives an overview of the development of the international biobank standard ISO 20387 and the commitment of German biobank experts in the ISO committee TC276. Less attention than the biobank standard per se has so far been paid to the basic mechanisms by which standards are developed and the potential of their application and accreditation. In this sense, this article deals with the motivation for active participation in standardization projects. We discuss the status of ISO 20387 as a conformity assessment standard and the consequence of accreditation as a performance monitor.

Nicotinamide N-Methyltransferase and Its Precursor Substrate Methionine Directly and Indirectly Control Malignant Metabolism During Progression of Renal Cell Carcinoma

BACKGROUND/AIM

Renal cell carcinoma (RCC) is one of the most common tumor diseases in adults, and new specific biomarkers are urgently needed to define diagnosis and prognosis of patients with RCC as well as monitor the outcome of therapeutic interventions. The enzyme nicotinamide N-methyltransferase (NNMT) is believed to represent such a marker molecule in RCC therapy.

MATERIALS AND METHODS

NNMT expression was examined by western blotting in samples from patients with RCC and in RCC cell lines. Effects of NNMT on cell growth and metabolism were assessed using the Hoechst 33342 reagent assay and Vita-Orange cell viability assay. Incubation experiments were performed to study the influence of methionine and interleukin-6 (IL6) on expression of NNMT.

RESULTS

In patient samples, NNMT was up-regulated depending on the stage of progression. Investigations in an RCC cell culture model showed that after modulation of NNMT expression, cellular metabolism, but not cell growth was affected. This regulatory function was also dependent on the presence of the NNMT precursor substrate methionine and IL6.

CONCLUSION

The metabolism-regulatory activity of NNMT depends on the precursor substrate methionine and the presence of IL6. The function of methionine appears to be dependent on the stage of progression, since in individual RCC cell lines, opposing effects on metabolism were demonstrated. This, in turn, reflects the thoroughly complex situation in the clinic.

The androgen receptor antagonist enzalutamide induces apoptosis, dysregulates the heat shock protein system, and diminishes the androgen receptor and estrogen receptor β1 expression in prostate cancer cells

Enzalutamide's accepted mode of action is by targeting the androgen receptor's (AR) activity. In clinical practice, enzalutamide demonstrates a good benefit-risk profile for the treatment of advanced prostate cancer (PC), even after poor response to standard antihormonal treatment. However, since both, well-established antiandrogens and enzalutamide, target AR functionality, we hypothesized that additional unknown mechanisms might be responsible for enzalutamide's superior anticancer activity. In the current study, PC cells were incubated with enzalutamide and enzalutamide-dependent modulation of apoptotic mechanisms were assessed via Western blot analysis, TDT-mediated dUTP-biotin nick end-labeling assay, and nuclear morphology assay. Alterations of heat shock protein (HSP), AR, and estrogen receptor (ER) expression were examined by Western blot analysis. Enzalutamide attenuated the proliferation of PC cells in a time- and dose-dependent manner. In the presence of enzalutamide, apoptosis occurred which was shown by increased BAX expression, decreased Bcl-2 expression, nuclear pyknosis, and genomic DNA fragmentation. Moreover, enzalutamide inhibited the expression of HSPs primarily involved in steroid receptor stabilization and suppressed AR and ERβ1 expression. This study demonstrates for the first time that enzalutamide treatment of PC cells triggers varying molecular mechanisms resulting in antiproliferative effects of the drug. In addition to the well-characterized antagonistic inhibition of AR functionality, we have shown that enzalutamide also affects the intracellular synthesis of steroid receptor-associated HSPs, thereby diminishing the expression of AR and ERβ1 proteins and inducing apoptotic pathways. According to an indirect attenuation of HSP-associated factors such as steroid receptors, endometrial carcinoma, uterine leiomyosarcoma, and mamma carcinoma cells also demonstrated inhibited cell growth in the presence of enzalutamide. Our data, therefore, suggest that enzalutamide's high efficacy is at least partially independent of AR and p53 protein expression, which are frequently lost in advanced PC.

Cabazitaxel inhibits prostate cancer cell growth by inhibition of androgen receptor and heat shock protein expression

PURPOSE

Cabazitaxel, a semi-synthetic taxane of the third generation, inhibits prostate cancer (PC) cell growth by affecting the microtubule architecture. Since cabazitaxel has also been demonstrated to inhibit androgen receptor (AR) functionality, AR and AR-associated heat shock protein (HSP) expressions in the presence of cabazitaxel were characterized.

METHODS

AR and HSP expressions were assessed via Western blotting utilizing a PC-cell-line in vitro system incubated with cabazitaxel.

RESULTS

Incubation experiments with 0.3 nM cabazitaxel exhibited significantly reduced levels of AR and the AR-associated factors HSP90α, HSP40, and HSP70/HSP90 organising protein. Furthermore, expression of the anti-apoptotic factor HSP60 was suppressed. In contrast to other anticancer compounds, cabazitaxel did not alter the cytoprotective chemoresistance factor HSP27.

CONCLUSIONS

Despite the deregulation of microtubule organisation, cabazitaxel has been shown to suppress the expression of HSP. Very notably, and may be as a result of down-regulated HSP, cabazitaxel additionally inhibits the expression of the AR in AR-positive PC cells. Thus, cabazitaxel bears an additional anti-proliferative activity which is at least in part specific for PC cells.

SWITCH II: Phase III randomized, sequential, open-label study to evaluate the efficacy and safety of sorafenib-pazopanib versus pazopanib-sorafenib in the treatment of advanced or metastatic renal cell carcinoma (AUO AN 33/11)

PURPOSE

This trial compared the sequential therapy with the multikinase inhibitor sorafenib (So) followed by pazopanib (Pa) or vice versa in advanced/metastatic renal cell carcinoma (mRCC) patients.

METHODS

This multicenter, randomized phase 3 study assessed the sequential use of So-Pa versus Pa-So in patients with mRCC without prior systemic therapy. Pts were randomized to So 2 × 400 mg/day followed by Pa 1 × 800 mg/day in case of progression or intolerable toxicity or vice versa. Primary endpoint was total PFS (tPFS), defined as time from randomization to progression, or death during second-line therapy. Key secondary endpoints included overall survival (OS), first-line PFS, disease control rate (DCR) and safety.

RESULTS

A total of 377 pts were randomized (So-Pa, n = 189; Pa-So, n = 188). Recruitment of a total 544 pts was calculated, but actual accrual rate turned out to be lower than expected. The primary endpoint median tPFS was 8.6 mo (95% CI 7.7-10.2) for So-Pa and 12.9 mo (95% CI 10.8-15.2) for Pa-So with a hazard ratio (HR) of 1.36 (upper limit of one-sided 95% CI 1.68), which exceeded a predefined HR <1.225 as a one-sided 95% confidence interval. Non-inferiority of So-Pa regarding tPFS was not met. Secondary endpoints displayed marked statistical differences in favor of Pa-So in first-line PFS and DCR but not for OS and 2nd-line PFS. Side effect profiles were consistent with known toxicities of the respective multikinase-inhibitor including diarrhea, fatigue, hand-foot skin reaction and hypertension.

CONCLUSIONS

Non-inferiority of the primary endpoint tPFS could not be demonstrated for So-Pa. The results for first-line PFS and DCR favored the Pa-So sequence.

TRIAL REGISTRATION

NCT01613846, www.clinicaltrials.gov.

Enemy recognition is linked to soldier size in a polymorphic stingless bee

Many ant and termite colonies are defended by soldiers with powerful mandibles or chemical weaponry. Recently, it was reported that several stingless bee species also have soldiers for colony defence. These soldiers are larger than foragers, but otherwise lack obvious morphological adaptations for defence. Thus, how these soldiers improve colony fitness is not well understood. Robbing is common in stingless bees and we hypothesized that increased body size improves the ability to recognize intruders based on chemosensory cues. We studied the Neotropical species Tetragonisca angustula and found that large soldiers were better than small soldiers at recognizing potential intruders. Larger soldiers also had more olfactory pore plates on their antennae, which is likely to increase their chemosensory sensitivity. Our results suggest that improved enemy recognition might select for increased guard size in stingless bees.

BDNF: mRNA expression in urine cells of patients with chronic kidney disease and its role in kidney function

Podocyte loss and changes to the complex morphology are major causes of chronic kidney disease (CKD). As the incidence is continuously increasing over the last decades without sufficient treatment, it is important to find predicting biomarkers. Therefore, we measured urinary mRNA levels of podocyte genes NPHS1, NPHS2, PODXL and BDNF, KIM‐1, CTSL by qRT‐PCR of 120 CKD patients. We showed a strong correlation between BDNF and the kidney injury marker KIM‐1, which were also correlated with NPHS1, suggesting podocytes as a contributing source. In human biopsies, BDNF was localized in the cell body and major processes of podocytes. In glomeruli of diabetic nephropathy patients, we found a strong BDNF signal in the remaining podocytes. An inhibition of the BDNF receptor TrkB resulted in enhanced podocyte dedifferentiation. The knockdown of the orthologue resulted in pericardial oedema formation and lowered viability of zebrafish larvae. We found an enlarged Bowman's space, dilated glomerular capillaries, podocyte loss and an impaired glomerular filtration. We demonstrated that BDNF is essential for glomerular development, morphology and function and the expression of BDNF and KIM‐1 is highly correlated in urine cells of CKD patients. Therefore, BDNF mRNA in urine cells could serve as a potential CKD biomarker.

MicroRNA-1 and MicroRNA-21 Individually Regulate Cellular Growth of Non-malignant and Malignant Renal Cells

BACKGROUND/AIM

Due to its poor prognosis, it is increasingly necessary to understand the biology of renal cell cancer (RCC). Therefore, we investigated the role of microRNAs miR-1 and miR-21 in the growth of RCC cells compared to that of non-malignant renal cells.

MATERIALS AND METHODS

Four malignant cell lines (Caki-1, 786-O, RCC4, A498) were examined regarding their cell growth, microRNA and telomerase expression, and were compared to non-malignant RC-124 renal cells.

RESULTS

Inconsistencies appeared in the panel of RCC cells regarding antiproliferative and proliferative properties of miR-1 and miR-21, respectively. Notably, and most likely due to immortaliziation, non-malignant RC-124 cells exhibited telomerase expression and activity.

CONCLUSION

miR-1 and miR-21 functionality in cancer progression, particularly in tumor growth, may be more dependent on the individual cellular context and may reflect RCC heterogeneity. Thus, both microRNAs, in combination with other stratifying biomarkers, may be useful in terms of RCC diagnosis, prognosis, or treatment response.

Transplantation of Free and Microencapsulated Islets in Rats: Evidence for the Requirement of An Increased Islet Mass for Transplantation into the Peritoneal Site

Microencapsulation of islets of Langerhans may avoid the necessity of a permanent immunosuppressive drug therapy and opens up new perspectives for xenotransplantation in the treatment of insulin dependent diabetes. In a mouse model we recently showed long-term normoglycemia after microencapsulated xenotransplantation. Since the acceptance of mice to any kind of foreign material is quite high we assume that the rat model better reflects the situation of higher mammalians or even humans. Due to the volume of the transplanted material (i.e. islets + alginate-capsule) only the peritoneal cavity can be used up to now. The quantity of islets necessary to normalize the non-fasting blood glucose level was much higher than expected and free transplants needed even a higher amount of islets than encapsulated ones (3000 encapsulated vs. 2 x 3000 non-encapsulated). Transplantation beneath the kidney capsule was successful with only 1200-1500 islets per rat proving the metabolic potency of the islets. Implantation of empty capsules did not alter the diabetic state. We conclude that the alginate matrix may act as a “spacer” creating a distance between the consuments of a lacking substrate esp. oxygen in an unfavourable environment and perhaps protect it from unspecific mediators released during the postoperative period. Our findings underline the necessity for smaller capsules that would enable us to use other transplantation sites.