Early kinetics of C-reactive protein as prognosticator for survival in a real-world cohort of patients with metastatic renal cell cancer under first-line therapy with immune checkpoint inhibitors

PURPOSE

This study investigated the prognostic potential of baseline C-reactive protein (CRP) levels and early CRP kinetics in a real-world cohort of patients with metastatic renal cell carcinoma (mRCC) under first-line (1L) therapy with immune checkpoint inhibitors (CPI).

METHODS/PATIENTS

Analyses were performed retrospectively in a cohort of 61 mRCC patients under CPI-based 1L therapy. Patients were stratified based on baseline CRP (< 10 vs ≥ 10 mg/l) and CRP change within the initial three months of CPI therapy (normal: baseline < 10 mg/l, normalized: baseline ≥ 10 mg/l and nadir < 10 mg/l, non-normalized: baseline and nadir ≥ 10 mg/l). Finally, the association of baseline CRP and CRP change with progression-free (PFS) and overall survival (OS) was evaluated.

RESULTS

Baseline CRP was not significantly associated with both PFS (p = 0.666) and OS (p = 0.143). Following stratification according to early CRP kinetics, 23, 25 and 13 patients exhibited normal, normalized and non-normalized CRP levels, respectively. Patients with normal and normalized CRP had a markedly prolonged PFS (p = 0.091) and OS (p = 0.008) compared to patients with non-normalized CRP. Consequently, significantly better PFS (p = 0.031) and OS (p = 0.002) were observed for the combined normal-normalized group. In multivariate analysis including ECOG and IMDC risk, normalized CRP kinetics alone or in combination with the normal group was identified as significant independent risk factor for OS, whereas a statistical trend was observed for PFS.

CONCLUSIONS

The present study emphasizes the prognostic potential of early CRP kinetics in CPI-treated mRCC. As a standard laboratory parameter, CRP can be easily implemented into clinical routine to facilitate therapy monitoring.

Early CRP kinetics to predict long-term efficacy of first-line immune-checkpoint inhibition combination therapies in metastatic renal cell carcinoma: an updated multicentre real-world experience applying different CRP kinetics definitions

Objectives

Although biomarkers predicting therapy response in first-line metastatic renal carcinoma (mRCC) therapy remain to be defined, C-reactive protein (CRP) kinetics have recently been associated with immunotherapy (IO) response. Here, we aimed to assess the predictive and prognostic power of two contemporary CRP kinetics definitions in a large, real-world first-line mRCC cohort.

Methods

Metastatic renal carcinoma patients treated with IO-based first-line therapy within 5 years were retrospectively included in this multicentre study. According to Fukuda et al., patients were defined as 'CRP flare-responder', 'CRP responder' and 'non-CRP responder'; according to Ishihara et al., patients were defined as 'normal', 'normalised' and 'non-normalised' based on their early CRP kinetics. Patient and tumor characteristics were compared, and treatment outcome was measured by overall (OS) and progression-free survival (PFS), including multivariable Cox regression analyses.

Results

Out of 316 mRCC patients, 227 (72%) were assigned to CRP groups according to Fukuda. Both CRP flare- (HR [Hazard ratio]: 0.59) and CRP responders (HR: 0.52) had a longer PFS, but not OS, than non-CRP responders. According to Ishihara, 276 (87%) patients were assigned to the respective groups, and both normal and normalised patients had a significantly longer PFS and OS, compared with non-normalised group.

Conclusion

Different early CRP kinetics may predict therapy response in first-line mRCC therapy in a large real-world cohort. However, further research regarding the optimal timing and frequency of measurement is needed.

Comprehensive Evaluation of Multiple Approaches Targeting ABCB1 to Resensitize Docetaxel-Resistant Prostate Cancer Cell Lines

Docetaxel (DTX) is a mainstay in the treatment of metastatic prostate cancer. Failure of DTX therapy is often associated with multidrug resistance caused by overexpression of efflux membrane transporters of the ABC family such as the glycoprotein ABCB1. This study investigated multiple approaches targeting ABCB1 to resensitize DTX-resistant (DTXR) prostate cancer cell lines. In DU145 DTXR and PC-3 DTXR cells as well as age-matched parental controls, the expression of selected ABC transporters was analyzed by quantitative PCR, Western blot, flow cytometry and immunofluorescence. ABCB1 effluxing activity was studied using the fluorescent ABCB1 substrate rhodamine 123. The influence of ABCB1 inhibitors (elacridar, tariquidar), ABCB1-specific siRNA and inhibition of post-translational glycosylation on DTX tolerance was assessed by cell viability and colony formation assays. In DTXR cells, only ABCB1 was highly upregulated, which was accompanied by a strong effluxing activity and additional post-translational glycosylation of ABCB1. Pharmacological inhibition and siRNA-mediated knockdown of ABCB1 completely resensitized DTXR cells to DTX. Inhibition of glycosylation with tunicamycin affected DTX resistance partially in DU145 DTXR cells, which was accompanied by a slight intracellular accumulation and decreased effluxing activity of ABCB1. In conclusion, DTX resistance can be reversed by various strategies with small molecule inhibitors representing the most promising and feasible approach.

Bevacizumab May Differentially Improve Prognosis of Advanced Ovarian Cancer Patients with Low Expression of VEGF-A165b, an Antiangiogenic VEGF-A Splice Variant

PURPOSE

The identification of a robust IHC marker to predict the response to antiangiogenic bevacizumab in ovarian cancer is of high clinical interest. VEGF-A, the molecular target of bevacizumab, is expressed as multiple isoforms with pro- or antiangiogenic properties, of which VEGF-A165b is the most dominant antiangiogenic isoform. The balance of VEGF-A isoforms is closely related to the angiogenic capacity of a tumor and may define its vulnerability to antiangiogenic therapy. We investigated whether the expression of VEGF-A165b could be related to the effect of bevacizumab in advanced ovarian cancer patients.

EXPERIMENTAL DESIGN

Formalin-fixed paraffin-embedded tissues from 413 patients of the ICON7 multicenter phase III trial, treated with standard platinum-based chemotherapy with or without bevacizumab, were probed for VEGF-A165b expression by IHC.

RESULTS

In patients with low VEGF-A165b expression, the addition of bevacizumab to standard platinum-based chemotherapy significantly improved progression-free (HR: 0.727; 95% CI, 0.538-0.984; P = 0.039) and overall survival (HR: 0.662; 95% CI, 0.458-0.958; P = 0.029). Multivariate analysis showed that the addition of bevacizumab in low VEGF-A165b-expressing patients conferred significant improvements in progression-free survival (HR: 0.610; 95% CI, 0.446-0.834; P = 0.002) and overall survival (HR: 0.527; 95% CI, 0.359-0.775; P = 0.001), independently from established risk factors.

CONCLUSIONS

We demonstrate for the first time that bevacizumab may differentially improve the prognosis of advanced ovarian cancer patients with low expression of VEGF-A165b, an antiangiogenic VEGF-A splice variant. We envision that this novel biomarker could be implemented into routine diagnostics and may have direct clinical implications for guiding bevacizumab-related treatment decisions in advanced ovarian cancer patients.

Acquired resistance to irradiation or docetaxel is not associated with cross-resistance to cisplatin in prostate cancer cell lines

PURPOSE

Platinum chemotherapy can be considered to treat metastatic castration-resistant prostate cancer (mCRPC) with features of neuroendocrine differentiation. However, platinum compounds are generally only applied after the failure of multiple prior-line treatment options. This study investigated whether acquired resistance against ionizing radiation or docetaxel chemotherapy-two commonly applied treatment modalities in prostate cancer-influences the cisplatin (CDDP) tolerance in mCRPC cell line models.

METHODS

Age-matched parental as well as radio- or docetaxel-resistant DU145 and PC-3 cell lines were treated with CDDP and their sensitivity was assessed by measurements of growth rates, viability, apoptosis, metabolic activity and colony formation ability.

RESULTS

The data suggest that docetaxel resistance does not influence CDDP tolerance in all tested docetaxel-resistant cell lines. Radio-resistance was associated with sensitization to CDDP in PC-3, but not in DU145 cells. In general, DU145 cells tolerated higher CDDP concentrations than PC-3 cells regardless of acquired resistances. Furthermore, non-age-matched treatment-naïve PC-3 cells exhibited significantly different CDDP tolerances.

CONCLUSION

Like patients, different mCRPC cell lines exhibit significant variability regarding CDDP tolerance. The presented in vitro data suggest that previous radiation treatment may be associated with a moderate sensitization to CDDP in an isogenic and age-matched setting. Therefore, previous radiotherapy or docetaxel chemotherapy might be no contraindication against initiation of platinum chemotherapy in selected mCRPC patients.

Serum miRNAs Support the Indication for MRI-Ultrasound Fusion-Guided Biopsy of the Prostate in Patients with Low-PI-RADS Lesions

Multiparametric MRI (mpMRI) and targeted biopsy of the prostate enhance the tumor detection rate. However, the prediction of clinically significant prostate cancer (PCa) is still limited. Our study tested the additional value of serum levels of selected miRNAs in combination with clinical and mpMRI information for PCa prediction and classification. A total of 289 patients underwent targeted mpMRI-ultrasound fusion-guided prostate biopsy complemented by systematic biopsy. Serum miRNA levels of miRNAs (miR-141, miR-375, miR-21-5p, miR-320b, miR-210-3p, let-7c, and miR-486) were determined by quantitative PCR. Detection of any PCa and of significant PCa were the outcome variables. The patient age, pre-biopsy PSA level, previous biopsy procedure, PI-RADS score, and serum miRNA levels were covariates for regularized binary logistic regression models. The addition of miRNA expression of miR-486 and let-7c to the baseline model, containing only clinical parameters, increased the predictive accuracy. Particularly in patients with PI-RADS ≤3, we determined a sensitivity for detecting significant PCa (Gleason score ≥ 7a corresponding to Grade group ≥2) of 95.2%, and an NPV for absence of significant PCa of 97.1%. This accuracy could be useful to support patient counseling in selected cases.

Soluble Neuropilin-1 is an independent marker of poor prognosis in early breast cancer

Background

Neuropilin-1 (NRP-1) is a transmembrane protein that acts as a multifunctional non-tyrosine kinase receptor with an established role in development and immunity. NRP-1 also regulates tumor biology, and high expression levels of tissue NRP-1 have been associated with a poor prognosis. Recently, ELISA-based quantification of soluble NRP-1 (sNRP-1) has become available, but little is known about the prognostic value of sNRP-1 in malignancies.

Materials and methods

We measured sNRP-1 in the serum of 509 patients with primary early breast cancer (BC) at the time of diagnosis using ELISA.

Results

Mean serum values of sNRP-1 were 1.88 ± 0.52 nmol/l (= 130.83 ± 36.24 ng/ml). SNRP-1 levels weakly correlated with age, and were higher in peri- and postmenopausal patients compared to premenopausal patients, respectively (p < 0.0001). Low levels of sNRP-1 were associated with a significant survival benefit compared to high sNRP-1 levels at baseline (p = 0.005; HR 1.94; 95%CI 1.23–3.06). These findings remained significant after adjustment for tumor stage including lymph node involvement, grading, hormone receptor, HER2 status, and age (p = 0.022; HR 1.78; 95%CI 1.09–2.91).

Conclusion

Our findings warrant further investigations into the prognostic and therapeutic potential of sNRP-1 in BC.

Evaluation of MicroRNAs as Non-Invasive Diagnostic Markers in Urinary Cells from Patients with Suspected Prostate Cancer

Currently used tumor markers for early diagnosis of prostate cancer (PCa) are often lacking sufficient specificity and sensitivity. Therefore, the diagnostic potential of selected microRNAs in comparison to serum PSA levels and PSA density (PSAD) was explored. A panel of 12 PCa-associated microRNAs was quantified by qPCR in urinary sediments from 50 patients with suspected PCa undergoing prostate biopsy, whereupon PCa was detected in 26 patients. Receiver operating characteristic (ROC) curve analyses revealed a potential for non-invasive urine-based PCa detection for miR-16 (AUC = 0.744, p = 0.012; accuracy = 76%) and miR-195 (AUC = 0.729, p = 0.017; accuracy = 70%). While serum PSA showed an insufficient diagnostic value (AUC = 0.564, p = 0.656; accuracy = 50%) in the present cohort, PSAD displayed an adequate diagnostic performance (AUC = 0.708, p = 0.031; accuracy = 70%). Noteworthy, the combination of PSAD with the best candidates miR-16 and miR-195 either individually or simultaneously improved the diagnostic power (AUC = 0.801–0.849, p < 0.05; accuracy = 76–90%). In the sub-group of patients with PSA ≤ 10 ng/mL (n = 34), an inadequate diagnostic power of PSAD alone (AUC = 0.595, p = 0.524; accuracy = 68%) was markedly surpassed by miR-16 and miR-195 individually as well as by their combination with PSAD (AUC = 0.772–0.882, p < 0.05; accuracy = 74–85%). These findings further highlight the potential of urinary microRNAs as molecular markers with high clinical performance. Overall, these results need to be validated in a larger patient cohort.

ProstaTrend-A Multivariable Prognostic RNA Expression Score for Aggressive Prostate Cancer

BACKGROUND

Prostate cancer (PCa) is the most prevalent solid cancer among men in Western Countries. The clinical behavior of localized PCa is highly variable. Some cancers are aggressive leading to death, while others can even be monitored safely. Hence, there is a high clinical need for precise biomarkers for identification of aggressive disease in addition to established clinical parameters.

OBJECTIVE

To develop an RNA expression-based score for the prediction of PCa prognosis that facilitates clinical decision making.

DESIGN, SETTING, AND PARTICIPANTS

We assessed 233 tissue specimens of PCa patients with long-term follow-up data from fresh-frozen radical prostatectomies (RPs), from formalin-fixed and paraffin-embedded RP specimens and biopsies by transcriptome-wide next-generation sequencing and customized expression microarrays.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

We applied Cox proportional hazard models to the cohorts from different platforms and specimen types. Evidence from these models was combined by fixed-effect meta-analysis to identify genes predictive of the time to death of disease (DoD). Genes were combined by a weighted median approach into a prognostic score called ProstaTrend and transferred for the prediction of biochemical recurrence (BCR) after RP in an independent cohort of The Cancer Genome Atlas (TCGA).

RESULTS AND LIMITATIONS

ProstaTrend comprising ∼1400 genes was significantly associated with DoD in the training cohort of PCa patients treated by RP (leave-one-out cross-validation, Cox regression: p=2e-09) and with BCR in the TCGA validation cohort (Cox regression: p=3e-06). The prognostic impact persisted after multivariable Cox regression analysis adjusting for Gleason grading group (GG) ≥3 and resection status (p=0.001; DoD, training cohort) and for GG≥3, pathological stage ≥T3, and resection state (p=0.037; BCR, validation cohort).

CONCLUSIONS

ProstaTrend is a transcriptome-based score that predicts DoD and BCR in cohorts of PCa patients treated with RP.

PATIENT SUMMARY

ProstaTrend provides molecular patient risk stratification after radical prostatectomy.

Urinary MicroRNAs as Potential Markers for Non-Invasive Diagnosis of Bladder Cancer

Currently, voided urine cytology (VUC) serves as the gold standard for the detection of bladder cancer (BCa) in urine. Despite its high specificity, VUC has shortcomings in terms of sensitivity. Therefore, alternative biomarkers are being searched, which might overcome these disadvantages as a useful adjunct to VUC. The aim of this study was to evaluate the diagnostic potential of the urinary levels of selected microRNAs (miRs), which might represent such alternative biomarkers due to their BCa-specific expression. Expression levels of nine BCa-associated microRNAs (miR-21, -96, -125b, -126, -145, -183, -205, -210, -221) were assessed by quantitative PCR in urine sediments from 104 patients with primary BCa and 46 control subjects. Receiver operating characteristic (ROC) curve analyses revealed a diagnostic potential for miR-96, -125b, -126, -145, -183, and -221 with area under the curve (AUC) values between 0.605 and 0.772. The combination of the four best candidates resulted in sensitivity, specificity, positive and negative predictive values (NPV), and accuracy of 73.1%, 95.7%, 97.4%, 61.1%, and 80.0%, respectively. Combined with VUC, sensitivity and NPV could be increased by nearly 8%, each surpassing the performance of VUC alone. The present findings suggested a diagnostic potential of miR-125b, -145, -183, and -221 in combination with VUC for non-invasive detection of BCa in urine.

Diphenhydramine increases the therapeutic window for platinum drugs by simultaneously sensitizing tumor cells and protecting normal cells

Platinum-based compounds remain a well-established chemotherapy for cancer treatment despite their adverse effects which substantially restrict the therapeutic windows of the drugs. Both the cell type-specific toxicity and the clinical responsiveness of tumors have been associated with mechanisms that alter drug entry and export. We sought to identify pharmacological agents that promote cisplatin (CP) efficacy by augmenting the levels of drug-induced DNA lesions in malignant cells and simultaneously protecting normal tissues from accumulating such damage and from functional loss. Formation and persistence of platination products in the DNA of individual nuclei were measured in drug-exposed cell lines, in primary human tumor cells and in tissue sections using an immunocytochemical method. Using a mouse model of CP-induced toxicity, the antihistaminic drug diphenhydramine (DIPH) and two methylated derivatives decreased DNA platination in normal tissues and also ameliorated nephrotoxicity, ototoxicity, and neurotoxicity. In addition, DIPH sensitized multiple cancer cell types, particularly ovarian cancer cells, to CP by increasing intracellular uptake, DNA platination, and/or apoptosis in cell lines and in patient-derived primary tumor cells. Mechanistically, DIPH diminished transport capacity of CP efflux pumps MRP2, MRP3, and MRP5 particularly in its C2+C6 bimethylated form. Overall, we demonstrate that DIPH reduces side effects of platinum-based chemotherapy and simultaneously inhibits key mechanisms of platinum resistance. We propose that measuring DNA platination after ex vivo exposure may predict the responsiveness of individual tumors to DIPH-like modulators.

High serum levels of periostin are associated with a poor survival in breast cancer

PURPOSE

Periostin is a secreted extracellular matrix protein, which was originally described in osteoblasts. It supports osteoblastic differentiation and bone formation and has been implicated in the pathogenesis of several human malignancies, including breast cancer. However, little is known about the prognostic value of serum periostin levels in breast cancer.

METHODS

In this study, we analyzed serum levels of periostin in a cohort of 509 primary, non-metastatic breast cancer patients. Disseminated tumor cell (DTC) status was determined using bone marrow aspirates obtained from the anterior iliac crests. Periostin levels were stratified according to several clinical parameters and Pearson correlation analyses were performed. Kaplan-Meier survival curves were assessed by using the log-rank (Mantel-Cox) test. To identify prognostic factors, multivariate Cox regression analyses were used.

RESULTS

Mean serum levels of periostin were 505 ± 179 pmol/l. In older patients (> 60 years), periostin serum levels were significantly increased compared to younger patients (540 ± 184 pmol/l vs. 469 ± 167 pmol/l; p < 0.0001) and age was positively correlated with periostin expression (p < 0.0001). When stratifying the cohort according to periostin serum concentrations, the overall and breast cancer-specific mortality were significantly higher in those patients with high serum periostin (above median) compared to those with low periostin during a mean follow-up of 8.5 years (17.7% vs. 11.4% breast cancer-specific death; p = 0.03; hazard ratio 1.65). Periostin was confirmed to be an independent prognostic marker for breast cancer-specific survival (p = 0.017; hazard ratio 1.79). No significant differences in serum periostin were observed when stratifying the patients according to their DTC status.

CONCLUSIONS

Our findings emphasize the relevance of periostin in breast cancer and reveal serum periostin as a potential marker for disease prediction, independent on the presence of micrometastases.

Linking NRP2 With EMT and Chemoradioresistance in Bladder Cancer

Neuropilin-2 (NRP2) is a prognostic indicator for reduced survival in bladder cancer (BCa) patients. Together with its major ligand, vascular endothelial growth factor (VEGF)-C, NRP2 expression is a predictive factor for treatment outcome in response to radiochemotherapy in BCa patients who underwent transurethral resection. Therefore, we investigated the benefit of combining cisplatin-based chemotherapy with irradiation treatment in the BCa cell line RT112 exhibiting or lacking endogenous NRP2 expression in order to evaluate NRP2 as potential therapeutic target. We have identified a high correlation of NRP2 and the glioma-associated oncogene family zinc finger 2 (GLI2) transcripts in the cancer genome atlas (TCGA) cohort of BCa patients and a panel of 15 human BCa cell lines. Furthermore, we used in vitro BCa models to show the transforming growth factor-beta 1 (TGFβ1)-dependent regulation of NRP2 and GLI2 expression levels. Since NRP2 was shown to bind TGFβ1, associate with TGFβ receptors, and enhance TGFβ1 signaling, we evaluated downstream signaling pathways using an epithelial-to-mesenchymal transition (EMT)-assay in combination with a PCR profiling array containing 84 genes related to EMT. Subsequent target validation in NRP2 knockout and knockdown models revealed secreted phosphoprotein 1 (SPP1/OPN/Osteopontin) as a downstream target positively regulated by NRP2.

Prognostic Value of RANKL/OPG Serum Levels and Disseminated Tumor Cells in Nonmetastatic Breast Cancer

PURPOSE

We assessed serum concentrations of the receptor activator of NFκB ligand (RANKL) and its decoy receptor, osteoprotegerin (OPG), two proteins implicated in the development and progression of breast cancer, in 509 patients with primary, nonmetastatic breast cancer. Then the results were evaluated with regards to the occurrence of bone metastases, the presence of disseminated tumor cells (DTC) in the bone marrow, survival, and risk of developing metastatic disease.

EXPERIMENTAL DESIGN

Before surgery, two bone marrow aspirates were analyzed for DTC using density centrifugation followed by immunocytochemistry (pan-cytokeratin antibody A45-B/B3). RANKL and OPG levels in the serum were measured by ELISA.

RESULTS

RANKL levels were significantly lower in women >60 years (P < 0.0001) and RANKL/OPG ratios higher in lymph node-positive patients (P < 0.05). High OPG serum levels were associated with a higher risk of death from breast cancer [HR 1.94; 95% confidence interval (CI) 1.23-3.07; P = 0.005] and OPG was an independent prognostic marker for breast cancer-specific survival (BCSS; multivariate analyses, P = 0.035). RANKL levels were 33% higher (P < 0.0001) in DTC^pos patients (41%), whereas high levels were associated with a significantly better BCSS in DTC^neg patients as compared with low levels (HR 0.524; 95% CI 0.30-0.95; P = 0.04). RANKL serum levels were significantly increased in patients who developed bone metastases (P = 0.01) and patients within the highest quartile of RANKL had a significantly increased risk of developing bone metastases compared with those in the lowest (HR 4.62; 95% CI 1.49-14.34; P = 0.03).

CONCLUSIONS

These findings warrant further investigation as they provide a rationale for novel diagnostic or therapeutic approaches.

Quantification of MicroRNAs in Urine-Derived Specimens

MicroRNAs are small noncoding RNAs which regulate the expression of genes involved in a multitude of cellular processes. Dysregulation of microRNAs and-in consequence-of the affected pathways is frequently observed in numerous pathologies including cancers. Therefore, tumor-related alterations in microRNA expression and function can reflect molecular processes of tumor onset and progression qualifying microRNAs as potential diagnostic and prognostic biomarkers.In particular, microRNAs with differential expression in bladder cancer (BCa) might represent promising tools for noninvasive tumor detection in urine. This would be helpful not only for diagnostic and monitoring purposes but also for therapeutic decisions. Detection and quantification of BCa-associated microRNAs in urine can be performed using the cellular sediment, which also contains BCa cells, or in exosomes originating from those cells. Methods for isolation of exosomes from urine, extraction of total RNA from cells and exosomes as well as techniques for RNA quantification, reverse transcription, and qPCR-based quantification of microRNA expression levels are described herein.

Systematic evaluation of oligodeoxynucleotide binding and hybridization to modified multi-walled carbon nanotubes

BACKGROUND

In addition to conventional chemotherapeutics, nucleic acid-based therapeutics like antisense oligodeoxynucleotides (AS-ODN) represent a novel approach for the treatment of bladder cancer (BCa). An efficient delivery of AS-ODN to the urothelium and then into cancer cells might be achieved by the local application of multi-walled carbon nanotubes (MWCNT). In the present study, pristine MWCNT and MWCNT functionalized with hydrophilic moieties were synthesized and then investigated regarding their physicochemical characteristics, dispersibility, biocompatibility, cellular uptake and mucoadhesive properties. Finally, their binding capacity for AS-ODN via hybridization to carrier strand oligodeoxynucleotides (CS-ODN), which were either non-covalently adsorbed or covalently bound to the different MWCNT types, was evaluated.

RESULTS

Pristine MWCNT were successfully functionalized with hydrophilic moieties (MWCNT-OH, -COOH, -NH2, -SH), which led to an improved dispersibility and an enhanced dispersion stability. A viability assay revealed that MWCNT-OH, MWCNT-NH2 and MWCNT-SH were most biocompatible. All MWCNT were internalized by BCa cells, whereupon the highest uptake was observed for MWCNT-OH with 40% of the cells showing an engulfment. Furthermore, all types of MWCNT could adhere to the urothelium of explanted mouse bladders, but the amount of the covered urothelial area was with 2-7% rather low. As indicated by fluorescence measurements, it was possible to attach CS-ODN by adsorption and covalent binding to functionalized MWCNT. Adsorption of CS-ODN to pristine MWCNT, MWCNT-COOH and MWCNT-NH2 as well as covalent coupling to MWCNT-NH2 and MWCNT-SH resulted in the best binding capacity and stability. Subsequently, therapeutic AS-ODN could be hybridized to and reversibly released from the CS-ODN coupled via both strategies to the functionalized MWCNT. The release of AS-ODN at experimental conditions (80 °C, buffer) was most effective from CS-ODN adsorbed to MWCNT-OH and MWCNT-NH2 as well as from CS-ODN covalently attached to MWCNT-COOH, MWCNT-NH2 and MWCNT-SH. Furthermore, we could exemplarily demonstrate that AS-ODN could be released following hybridization to CS-ODN adsorbed to MWCNT-OH at physiological settings (37 °C, urine).

CONCLUSIONS

In conclusion, functionalized MWCNT might be used as nanotransporters in antisense therapy for the local treatment of BCa.

Carbon nanomaterials sensitize prostate cancer cells to docetaxel and mitomycin C via induction of apoptosis and inhibition of proliferation

We have previously shown that carbon nanofibers (CNFs) and carbon nanotubes (CNTs) can sensitize prostate cancer (PCa) cells to platinum-based chemotherapeutics. In order to further verify this concept and to avoid a bias, the present study investigates the chemosensitizing potential of CNFs and CNTs to the conventional chemotherapeutics docetaxel (DTX) and mitomycin C (MMC), which have different molecular structures and mechanisms of action than platinum-based chemotherapeutics. DU-145 PCa cells were treated with DTX and MMC alone or in combination with the carbon nanomaterials. The impact of the monotreatments and the combinatory treatments on cellular function was then systematically analyzed by using different experimental approaches (viability, short-term and long-term proliferation, cell death rate). DTX and MMC alone reduced the viability of PCa cells to 94% and 68%, respectively, whereas a combined treatment with CNFs led to less than 30% remaining viable cells. Up to 17- and 7-fold higher DTX and MMC concentrations were needed in order to evoke a similar inhibition of viability as mediated by the combinatory treatments. In contrast, the dose of platinum-based chemotherapeutics could only be reduced by up to 3-fold by combination with carbon nanomaterials. Furthermore, combinatory treatments with CNFs led mostly to an additive inhibition of short- and long-term proliferation compared to the individual treatments. Also, higher cell death rates were observed in combinatory treatments than in monotreatments, e.g., a combination of MMC and CNFs more than doubled the cell death rate mediated by apoptosis. Combinations with CNTs showed a similar, but less pronounced impact on cellular functions. In summary, carbon nanomaterials in combination with DTX and MMC evoked additive to partly synergistic anti-tumor effects. CNFs and CNTs possess the ability to sensitize cancer cells to a wide range of structurally diverse chemotherapeutics and thus represent an interesting option for the development of multimodal cancer therapies. Co-administration of chemotherapeutics with carbon nanomaterials could result in a reduction of the chemotherapeutic dosage and thus limit systemic side effects.

MiR-26a and miR-138 block the G1/S transition by targeting the cell cycle regulating network in prostate cancer cells

PURPOSE

The tumor-suppressive microRNAs miR-26a and miR-138 are significantly down-regulated in prostate cancer (PCa) and have been identified as direct regulators of enhancer of zeste homolog 2 (EZH2), which is a known oncogene in PCa. In the present study, the influence of miR-26a and miR-138 on EZH2 and cellular function including the impact on the cell cycle regulating network was evaluated in PCa cells.

METHODS

PC-3 and DU-145 PCa cells were transfected with 100 nM of miRNA mimics, siRNA against EZH2 (siR-EZH2) or control constructs for 4 h. Analyses of gene expression and cellular function were conducted 48 h after transfection.

RESULTS

Both miRNAs influenced the EZH2 expression and activity only marginally, whereas siR-EZH2 led to a notable decrease of the EZH2 expression and activity. Both miRNAs inhibited short- and/or long-term proliferation of PCa cells but showed no effect on viability and apoptosis. In PC-3 cells, miR-26a and miR-138 caused a significant surplus of cells in the G0/G1 phase of 6 and 12 %, respectively, thus blocking the G1/S-phase transition. Treatment with siR-EZH2 was without substantial influence on cellular function and cell cycle. Therefore, alternative target genes involved in cell cycle regulation were identified in silico. MiR-26a significantly diminished the expression of its targets CCNE1, CCNE2 and CDK6, whereas CCND1, CCND3 and CDK6 were suppressed by their regulator miR-138.

CONCLUSIONS

The present findings suggest an anti-proliferative role for miR-26a and miR-138 in PCa by blocking the G1/S-phase transition independent of EZH2 but via a concerted inhibition of crucial cell cycle regulators.

Abstract 1278: Accumulation of tolerogenic human 6-sulfo LacNAc+ dendritic cells in renal cell carcinoma is associated with poor prognosis

6-sulfo LacNAc+ (slan) DCs, representing a myeloid human blood DC subset, produce various proinflammatory cytokines, display cytotoxic activity and efficiently stimulate natural killer (NK) cells and T lymphocytes. Recent studies demonstrated that slanDCs accumulate in metastatic tumor-draining lymph nodes from cancer patients, indicating that slanDCs may contribute to antitumor immunity.

We constructed tissue microarrays from primary clear-cell renal cell carcinomas (ccRCC) and paired non-neoplastic renal tissues from 265 patients who underwent radical/partial nephrectomy in the Department of Urology, University Clinic, TU Dresden. The slanDCs were identified by immunohistochemistry using a DD2 antibody, developed in the Institute of Immunology, TU Dresden. Freshly prepared tumor-infiltrating cells from 10 specimens were used for phenotypic characterization by flow cytometry. The effects of slanDCs and T-lymphocytes isolated from freshly prepared peripheral blood mononuclear cells on ACHN, CAKI-1 and on two native ccRCC cell lines were assessed by flow-cytomtery, proliferation assays. The frequency of slanDCs in ccRCC and paired non-neoplastic renal tissues were correlated with the clinico-pathological characteristics of patients. SlanDCs were detectable in the majority of primary tumors (93.2%), metastatic lymph nodes (87.5%) and distant metastases (85.1%). A significantly (p&lt;0.001) higher number of slanDCs were detected in primary ccRCC tissues (mean: 3.74 slanDC/mm2, range: 0-19.82 slanDC/mm2) compared to tumor-free tissues (mean: 1.19 slanDC/mm2, range: 0-9.9 slanDC/mm2). A higher density of slanDCs in ccRCC tissues was significantly correlated with a higher grading and stage of the primary tumor (p = 0.001 and p = 0.006 respectively), as well as with lymph node- or distant metastases (p = 0.039 and p&lt;0.001, respectively). Remarkably, a higher density of slanDCs was significantly correlated with a reduced progression-free, tumor-specific or overall survival of ccRCC patients. Freshly prepared ccRCC-infiltrating slanDCs expressed HLA-DR and low densities of CD86, but CD40, CD80, CD83 and CCR7 could not be detected. Whereas the proinflammatory cytokines TNF-α and IL-12 were not found, a proportion of slanDCs showed expression of the anti-inflammatory cytokine IL-10. Further studies revealed that primary ccRCC cells efficiently impair the capacity of slanDCs to stimulate CD4+ and CD8+ T-cell proliferation and Th1 programming. In addition, ccRCC cells significantly inhibited slanDC-mediated NK cell activation.

These findings indicate that higher slanDC numbers in ccRCC tissues are associated with poor prognosis. The induction of a tolerogenic phenotype in slanDCs leading to an insufficient activation of innate and adaptive antitumor immunity may represent a novel immune escape mechanism of ccRCC.

Citation Format: Marieta I. Toma, Rebekka Wehner, Anja Kloß, Kati Erdmann, Susanne Fuessel, Barbara Seliger, Dorothee Brech, Elfriede Noessner, Knut Schaekel, Manfred Wirth, Gustavo Baretton, Marc Schmitz. Accumulation of tolerogenic human 6-sulfo LacNAc+ dendritic cells in renal cell carcinoma is associated with poor prognosis. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1278. doi:10.1158/1538-7445.AM2015-1278

Accumulation of tolerogenic human 6-sulfo LacNAc dendritic cells in renal cell carcinoma is associated with poor prognosis

Dendritic cells (DCs) essentially contribute to the induction and regulation of innate and adaptive immunity. Based on these important properties, DCs may profoundly influence tumor progression in patients. However, little is known about the role of distinct human DC subsets in primary tumors and their impact on clinical outcome. In the present study, we investigated the characteristics of human 6-sulfo LacNAc (slan) DCs in clear cell renal cell carcinoma (ccRCC). slanDCs have been shown to display various tumor-directed properties and to accumulate in tumor-draining lymph nodes from patients. When evaluating 263 ccRCC and 227 tumor-free tissue samples, we found increased frequencies of slanDCs in ccRCC tissues compared to tumor-free tissues. slanDCs were also detectable in the majority of 24 metastatic lymph nodes and 67 distant metastases from ccRCC patients. Remarkably, a higher density of slanDCs was significantly associated with a reduced progression-free, tumor-specific or overall survival of ccRCC patients. Tumor-infiltrating slanDCs displayed an immature phenotype expressing interleukin-10. ccRCC cells efficiently impaired slanDC-induced T-cell proliferation and programming as well as natural killer (NK) cell activation. In conclusion, these findings indicate that higher slanDC numbers in ccRCC tissues are associated with poor prognosis. The induction of a tolerogenic phenotype in slanDCs leading to an insufficient activation of innate and adaptive antitumor immunity may represent a novel immune escape mechanism of ccRCC. These observations may have implications for the design of therapeutic strategies that harness tumor-directed functional properties of DCs against ccRCC.

Aldehyde Dehydrogenase Is Regulated by β-Catenin/TCF and Promotes Radioresistance in Prostate Cancer Progenitor Cells

Radiotherapy is a curative treatment option in prostate cancer. Nevertheless, patients with high-risk prostate cancer are prone to relapse. Identification of the predictive biomarkers and molecular mechanisms of radioresistance bears promise to improve cancer therapies. In this study, we show that aldehyde dehydrogenase (ALDH) activity is indicative of radioresistant prostate progenitor cells with an enhanced DNA repair capacity and activation of epithelial-mesenchymal transition (EMT). Gene expression profiling of prostate cancer cells, their radioresistant derivatives, ALDH(+) and ALDH(-) cell populations revealed the mechanisms, which link tumor progenitors to radioresistance, including activation of the WNT/β-catenin signaling pathway. We found that expression of the ALDH1A1 gene is regulated by the WNT signaling pathway and co-occurs with expression of β-catenin in prostate tumor specimens. Inhibition of the WNT pathway led to a decrease in ALDH(+) tumor progenitor population and to radiosensitization of cancer cells. Taken together, our results indicate that ALDH(+) cells contribute to tumor radioresistance and their molecular targeting may enhance the effectiveness of radiotherapy.

Characterization of different carbon nanotubes for the development of a mucoadhesive drug delivery system for intravesical treatment of bladder cancer

In order to increase the effectiveness of therapeutics for bladder carcinoma (BCa) treatment, alternative strategies for intravesical applications are needed. The use of carbon nanotubes (CNTs) as basis for a multifunctional drug transporter is a promising possibility to combine traditional chemotherapeutics with innovative therapeutic agents such as antisense oligodeoxynucleotides or small interfering RNA. In the current study four CNT types varying in length and diameter (CNT-1, CNT-2, CNT-3, CNT-4) were synthesized and then characterized with different spectroscopic techniques. Compared to the pristine CNT-1 and CNT-3, the shortened CNT-2 and CNT-4 exhibited more defects and lower aspect ratios. To analyze their mucoadhesive properties, CNTs were exposed to mouse bladders ex vivo by using Franz diffusion cells. All four tested CNT types were able to adhere to the urothelium with a mean covering area of 5-10%. In vitro studies on UM-UC-3 and EJ28 BCa cells were conducted to evaluate the toxic potential of these CNTs. Viability and cytotoxicity assays revealed that the shortened CNT-2 and CNT-4 induced stronger inhibitory effects on BCa cells than CNT-1 and CNT-3. In conclusion, CNT-1 and CNT-3 showed the most promising properties for further optimization of a multifunctional drug transporter.

Prognostic impact of urokinase-type plasminogen activator system components in clear cell renal cell carcinoma patients without distant metastasis

Background

Members of the urokinase-type plasminogen activator (uPA) system including uPA, its receptor uPAR and the plasminogen activator inhibitor 1 (PAI-1) play an important role in tumour invasion and progression in a variety of tumour types. Since the majority of clear cell renal cell carcinoma (ccRCC) shows distant metastasis at time of diagnosis or later, the interplay of uPA, uPAR and PAI-1 might be of importance in this process determining the patients’ outcome.

Methods

Corresponding pairs of malignant and non-malignant renal tissue specimens were obtained from 112 ccRCC patients without distant metastasis who underwent tumour nephrectomy. Tissue extracts prepared from fresh-frozen tissue samples by detergent extraction were used for the determination of antigen levels of uPA, uPAR and PAI-1 by ELISA. Antigen levels were normalised to protein concentrations and expressed as ng per mg of total protein.

Results

Antigen levels of uPA, uPAR, and PAI-1 correlated with each other in the malignant tissue specimens (r_s=0.51-0.65; all P<0.001). Antigen levels of uPA system components were significantly higher in tissue extracts of non-organ confined tumours (pT3+4) compared to organ-confined tumours (pT1+2; all P<0.05). Significantly elevated levels of uPAR and PAI-1 were also observed in high grade ccRCC. When using median antigen levels as cut-off points, all three uPA system factors were significant predictors for disease-specific survival (DSS) in univariate Cox’s regression analyses. High levels of uPA and uPAR remained independent predictors for DSS with HR=2.86 (95% CI 1.07-7.67, P=0.037) and HR=4.70 (95% CI 1.51-14.6, P=0.008), respectively, in multivariate Cox’s regression analyses. A combination of high antigen levels of uPA and/or uPAR further improved the prediction of DSS in multivariate analysis (HR=14.5, 95% CI 1.88-111.1, P=0.010). Moreover, high uPA and/or uPAR levels defined a patient subgroup of high risk for tumour-related death in ccRCC patients with organ-confined disease (pT1+2) (HR=9.83, 95% CI 1.21-79.6, P=0.032).

Conclusions

High levels of uPA and uPAR in tumour tissue extracts are associated with a significantly shorter DSS of ccRCC patients without distant metastases.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2407-14-974) contains supplementary material, which is available to authorized users.

Chemosensitizing effects of carbon-based nanomaterials in cancer cells: enhanced apoptosis and inhibition of proliferation as underlying mechanisms

Recent studies have shown that carbon nanomaterials such as carbon nanofibres (CNFs) and multi-walled carbon nanotubes (CNTs) can exert antitumor activities themselves and sensitize cancer cells to conventional chemotherapeutics such as carboplatin and cisplatin. In the present study, the chemosensitizing effect of CNFs and CNTs on cancer cells of urological origin was investigated regarding the underlying mechanisms. Prostate cancer (DU-145, PC-3) and bladder cancer (EJ28) cells were treated with carbon nanomaterials (CNFs, CNTs) and chemotherapeutics (carboplatin, cisplatin) alone as well as in combination for 24 h. Forty-eight(EJ28) or 72 h (DU-145, PC-3) after the end of treatment the effects on cellular proliferation,clonogenic survival, cell death rate and cell cycle distribution were evaluated. Depending on the cell line, simultaneous administration of chemotherapeutics and carbon nanomaterials produced an additional inhibition of cellular proliferation and clonogenic survival of up to 77% and 98%, respectively, compared to the inhibitory effects of the chemotherapeutics alone. These strongly enhanced antiproliferative effects were accompanied by an elevated cell death rate, which was predominantly mediated via apoptosis and not by necrosis. The antitumor effects of combinations with CNTs were less pronounced than those with CNFs. The enhanced effects of the combinatory treatments on cellular function were mostly of additive to partly synergistic nature. Furthermore, cell cycle analysis demonstrated an arrest at the G2/M phase mediated by a monotreatment with chemotherapeutics. Following combinatory treatments, mostly less than or nearly additive increases of cell fractions in the G2/M phase could be observed. In conclusion,the pronounced chemosensitizing effects of CNFs and CNTs were mediated by an enhanced apoptosis and inhibition of proliferation. The combination of carbon-based nanomaterials and conventional chemotherapeutics represents a novel approach in cancer therapy to bypass chemoresistance by minimizing the chemotherapeutic dosing.

Abstract 39: Expression of uPA-system members correlate with the clinico-pathological parameters of PCa patients

Background: Members of the urokinase-type plasminogen activator (uPA) system play an important role in tumor progression and angiogenesis in different human malignancies including breast, kidney, colon, stomach and prostate cancer (PCa). The objective of this study was to determine the mRNA expression and protein levels of uPA system components in tissue specimens and serum samples, respectively, from patients with PCa, and to assess their potential association with clinic-pathological parameters and overall survival (OS).

Material and methods: mRNA levels of uPA, its receptor (uPAR) and its inhibitor type 1 (PAI-1) were analyzed in corresponding malignant and adjacent non-malignant prostate tissue specimens from 132 PCa patients. Relative mRNA expression levels were determined by quantitative PCR and normalized to the reference gene TATA-box-binding protein. Pre-operative serum samples from 81 of the 132 PCa patients and 36 patients with benign prostatic hyperplasia (BPH) were analyzed for antigen levels of uPA system members by ELISA.

Results: mRNA levels of the uPA system components displayed significant correlations with each other in the tumor tissues (uPA vs. uPAR: rs = 0.550; uPA vs. PAI-1: rs = 0.552; uPAR vs. PAI-1: rs = 0.643; all P &lt; 0.001). A significantly decreased uPA mRNA expression in PCa tissue compared to the corresponding non-malignant tissue specimens was detected (data not shown). High mRNA expression of uPA and PAI-1 was significantly associated with a high Gleason score (P = 0.001 and P = 0.007, respectively; Fig. 2). Antigen levels of uPA and soluble uPAR (suPAR) in serum correlated weakly, but significantly, with each other (rs = 0.382, P &lt; 0.001). A significant association was found between elevated suPAR concentrations in serum and poor OS of PCa patients (P = 0.022, log rank test). In multivariate Cox's regression analysis (adj. for age, lymph node status, tumor stage and Gleason sum) a high suPAR level was associated with a 7.12-fold increased risk of death (P=0.027).

Conclusion: The observed association of high suPAR levels with poor survival of PCa patients is consistent with published data on patients afflicted with other types of solid cancer and strongly suggests a general prognostic impact of uPAR antigen levels in serum of cancer patients.

Citation Format: Omar Al-Janabi, Helge Taubert, Andrea Lohse-Fischer, Michael Fröhner, Sven Wach, Robert Stöhr, Bastian Keck, Max Burger, Wolf Wieland, Kati Erdmann, Manfred P. Wirth, Bernd Wullich, Gustavo Baretton, Viktor Magdolen, Matthias Kotzsch, Susanne Füssel. Expression of uPA-system members correlate with the clinico-pathological parameters of PCa patients. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 39. doi:10.1158/1538-7445.AM2014-39

High serum levels of Dickkopf-1 are associated with a poor prognosis in prostate cancer patients

Background

The Wnt inhibitor Dickkopf-1 (DKK-1) has been linked to the progression of malignant bone disease by impairing osteoblast activity. In addition, there is increasing data to suggest direct tumor promoting effects of DKK-1. The prognostic role of DKK-1 expression in prostate cancer remains unclear.

Methods

A prostate cancer tissue microarray (n = 400) was stained for DKK-1 and DKK-1 serum levels were measured in 80 patients with prostate cancer. The independent prognostic value of DKK-1 expression was assessed using multivariate analyses.

Results

DKK-1 tissue expression was significantly increased in prostate cancer compared to benign disease, but was not correlated with survival. However, high DKK-1 serum levels at the time of the diagnosis were associated with a significantly shorter overall and disease-specific survival. Multivariate analyses defined high serum levels of DKK-1 as an independent prognostic marker in prostate cancer (HR 3.73; 95%CI 1.44-9.66, p = 0.007).

Conclusion

High DKK-1 serum levels are associated with a poor survival in patients with prostate cancer. In light of current clinical trials evaluating the efficacy of anti-DKK-1 antibody therapies in multiple myeloma and solid malignancies, the measurement of DKK-1 in prostate cancer may gain clinical relevance.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2407-14-649) contains supplementary material, which is available to authorized users.

Lack of ephrin receptor A1 is a favorable independent prognostic factor in clear cell renal cell carcinoma

The EPH receptor tyrosine kinases and their cell-bound ligands, the ephrins, have been shown to be associated with cancer development and progression. In this study, mRNA and protein expression of the receptors EPHA1 and EPHA2 as well as of their ligand EFNA1 and their prognostic relevance in clear cell renal cell carcinoma was evaluated. Gene expression was measured in 75 cryo-preserved primary tumors and matched non-malignant renal specimens by quantitative PCR. Protein expression was analyzed by immunohistochemistry on tissue microarrays comprising non-malignant, primary tumors and metastatic renal tissues of 241 patients. Gene and protein expression of all three factors was altered in tumor specimens with EPHA1 and EPHA2 being generally diminished in tumors compared to normal renal tissue, whereas EFNA1 was commonly elevated. A positive EPHA1 and EPHA2 protein staining as well as a low EFNA1 protein level were significantly linked to more aggressive tumor features, but only a positive EPHA1 immunoreactivity was significantly associated with poor survival. In subgroup analyses, EPHA1 and EPHA2 protein levels were significantly higher in metastatic than in primary lesions. Patients with EPHA1/EPHA2-positive tumors or with tumors with positive EPHA1 and low EFNA1 immunoreactivity had the shortest survival rates compared to the respective other combinations. In a multivariate model, EPHA1 was an independent prognostic marker for different survival endpoints. In conclusion, an impaired EPH-ephrin signaling could contribute to the pathogenesis and progression of clear cell renal cell carcinoma.

Carbon nanofibers and carbon nanotubes sensitize prostate and bladder cancer cells to platinum-based chemotherapeutics

Recent data suggest that carbon nanomaterials can act as antitumor agents themselves by increasing the efficiency of cytotoxic agents when applied in combination. Here, carbon nanofibers (CNFs) and multi-walled carbon nanotubes (CNTs) were investigated regarding their impact on cellular function, cellular uptake and ability to sensitize cancer cells of urological origin to the conventional chemotherapeutics cisplatin and carboplatin. CNFs and CNTs (1-200 microg/ml) showed a low to moderate impairment of cellular function with CNFs being more deleterious than CNTs. Inhibition of cellular viability by the nanomaterials was about 20% at most. In combinatory treatments, CNFs and CNTs markedly enhanced the effects of cisplatin and carboplatin on cellular viability by 1.2- to 2.8-fold in prostate, bladder and cisplatin-resistant prostate cancer cells in comparison to the individual effects of the chemotherapeutics. Particularly the cell viability-diminishing effect of CNFs alone and in combination with the chemotherapeutics was more pronounced with dispersions prepared with human serum albumin than with phospholipid-polyethylene glycol. Albumin might mediate the cellular uptake of carbon nanomaterials which was underlined by the co-localization of albumin and carbon nanomaterials along the cellular surface as evidenced by fluorescence microscopy. Transmission electron microscopy revealed that both carbon nanomaterials were internalized by cancer cells, thereby possibly leading to an enhanced accumulation of the chemotherapeutic drugs. In fact, CNFs enhanced the cellular accumulation of carboplatin by 28% as compared to the single treatment with carboplatin. In conclusion, carbon nanomaterial-based applications could present a new strategy to overcome chemoresistance by sensitizing cancer cells to conventional chemotherapeutics.

Stage-dependent prognostic impact of molecular signatures in clear cell renal cell carcinoma

Purpose

To enhance prognostic information of protein biomarkers for clear cell renal cell carcinomas (ccRCCs), we analyzed them within prognostic groups of ccRCC harboring different tumor characteristics of this clinically and molecularly heterogeneous tumor entity.

Methods

Tissue microarrays from 145 patients with primary ccRCC were immunohistochemically analyzed for VHL (von Hippel-Lindau tumor suppressor), Ki67 (marker of proliferation 1), p53 (tumor protein p53), p21 (cyclin-dependent kinase inhibitor 1A), survivin (baculoviral IAP repeat containing 5), and UEA-1 (Ulex europaeus agglutinin I) to assess microvessel-density.

Results

When analyzing all patients, nuclear staining of Ki67 (hazard ratio [HR] 1.08, 95% confidence interval [CI] 1.04–1.12) and nuclear survivin (nS; HR 1.04, 95% CI 1.01–1.08) were significantly associated with disease-specific survival (DSS). In the cohort of patients with advanced localized or metastasized ccRCC, high staining of Ki67, p53 and nS predicted shorter DSS (Ki67: HR 1.07, 95% CI 1.02–1.11; p53: HR 1.05, 95% CI 1.01–1.09; nS: HR 1.08, 95% CI 1.02–1.14). In organ-confined ccRCC, patients with high p21-staining had a longer DSS (HR 0.96, 95% CI 0.92–0.99). In a multivariate model with stepwise backward elimination, tumor size and p21-staining showed a significant association with DSS in patients with “organ-confined” ccRCCs. The p21-staining increased the concordance index of tumor size from 0.75 to 0.78. In patients with “organ-confined” ccRCC, no disease-related deaths occurred in the group with p21-expression below the threshold of 32.5% p21-positive cells (log rank test: P=0.002).

Conclusion

The prognostic information of the studied protein biomarkers depended on anatomic tumor stages, which displayed different acquired biological tumor characteristics. Analysis of prognostic factors within different clinical ccRCC groups could help to enhance their prognostic power. The p21-staining was an independent prognostic factor and increased prognostic accuracy in a predictive model in “organ-confined” ccRCC.

Analyses of potential predictive markers and survival data for a response to sunitinib in patients with metastatic renal cell carcinoma

BACKGROUND

Patients with metastatic clear cell renal cell carcinoma (ccRCC) are frequently treated with tyrosine kinase inhibitors (TKI) such as sunitinib. It inhibits angiogenic pathways by mainly targeting the receptors of VEGF and PDGF. In ccRCC, angiogenesis is characterized by the inactivation of the von Hippel-Lindau gene (VHL) which in turn leads to the induction of HIF1α target genes such as CA9 and VEGF. Furthermore, the angiogenic phenotype of ccRCC is also reflected by endothelial markers (CD31, CD34) or other tumor-promoting factors like Ki67 or survivin.

METHODS

Tissue microarrays from primary tumor specimens of 42 patients with metastatic ccRCC under sunitinib therapy were immunohistochemically stained for selected markers related to angiogenesis. The prognostic and predictive potential of theses markers was assessed on the basis of the objective response rate which was evaluated according to the RECIST criteria after 3, 6, 9 months and after last report (12-54 months) of sunitinib treatment. Additionally, VHL copy number and mutation analyses were performed on DNA from cryo-preserved tumor tissues of 20 ccRCC patients.

RESULTS

Immunostaining of HIF-1α, CA9, Ki67, CD31, pVEGFR1, VEGFR1 and -2, pPDGFRα and -β was significantly associated with the sunitinib response after 6 and 9 months as well as last report under therapy. Furthermore, HIF-1α, CA9, CD34, VEGFR1 and -3 and PDGRFα showed significant associations with progression-free survival (PFS) and overall survival (OS). In multivariate Cox proportional hazards regression analyses high CA9 membrane staining and a response after 9 months were independent prognostic factors for longer OS. Frequently observed copy number loss and mutation of VHL gene lead to altered expression of VHL, HIF-1α, CA9, and VEGF.

CONCLUSIONS

Immunoexpression of HIF-1α, CA9, Ki67, CD31, pVEGFR1, VEGFR1 and -2, pPDGFRα and -β in the primary tumors of metastatic ccRCC patients might support the prediction of a good response to sunitinib treatment.

Enhanced inhibition of bladder cancer cell growth by simultaneous knockdown of antiapoptotic Bcl-xL and survivin in combination with chemotherapy

The overexpression of antiapoptotic genes, such as Bcl-xL and survivin, contributes to the increased survival of tumor cells and to the development of treatment resistances. In the bladder cancer cell lines EJ28 and J82, the siRNA-mediated knockdown of survivin reduces cell proliferation and the inhibition of Bcl-xL sensitizes these cells towards subsequent chemotherapy with mitomycin C and cisplatin. Therefore, the aim of this study was to analyze if the simultaneous knockdown of Bcl-xL and survivin might represent a more powerful treatment option for bladder cancer than the single inhibition of one of these target genes. At 96 h after transfection, reduction in cell viability was stronger after simultaneous inhibition of Bcl-xL and survivin (decrease of 40%-48%) in comparison to the single target treatments (decrease of 29% at best). Furthermore, simultaneous knockdown of Bcl-xL and survivin considerably increased the efficacy of subsequent chemotherapy. For example, cellular viability of EJ28 cells decreased to 6% in consequence of Bcl-xL and survivin inhibition plus cisplatin treatment whereas single target siRNA plus chemotherapy treatments mediated reductions down to 15%-36% only. In conclusion, the combination of simultaneous siRNA-mediated knockdown of antiapoptotic Bcl-xL and survivin-a multitarget molecular-based therapy-and conventional chemotherapy shows great potential for improving bladder cancer treatment.

siRNA-mediated inhibition of antiapoptotic genes enhances chemotherapy efficacy in bladder cancer cells

BACKGROUND

The up-regulation of antiapoptotic B-cell CLL/lymphoma 2 (BCL2), BCL2-like 1 (BCLXL), X-linked inhibitor of apoptosis (XIAP) and survivin is one mechanism by which cancer cells develop resistance towards chemotherapeutics. Therefore, the knockdown of these four genes could sensitise bladder cancer (BCa) cells towards chemotherapy.

MATERIALS AND METHODS

BCL2, BCLXL, XIAP and survivin were inhibited using siRNAs--either one target-alone or all four targets simultaneously--in EJ28 and J82 BCa cells. After 24 h, cells were treated with mitomycin C or cisplatin. Treatment effects were analysed regarding cell viability, cell count and apoptosis induction.

RESULTS

Knockdown of BCLXL and survivin, as well as the simultaneous inhibition of all four antiapoptotic genes, sensitised EJ28 and J82 cells towards mitomycin C and cisplatin.

CONCLUSION

Since the contribution of one antiapoptotic gene to chemotherapy response can vary between BCa cell lines, the simultaneous knockdown of multiple inhibitors of apoptosis might represent a more promising option for enhancing chemotherapy efficacy in BCa treatment.

Simultaneous siRNA-mediated knockdown of antiapoptotic BCL2, Bcl-xL, XIAP and survivin in bladder cancer cells

Bladder cancer (BCa) represents the ninth most common malignancy worldwide. Despite intensive treatment with surgery and chemotherapy the prognosis for BCa patients particularly at advanced stages is poor. The ability to evade apoptosis is a hallmark of cancer cells. Since the antiapoptotic genes BCL2, Bcl-xL, XIAP and survivin are frequently upregulated in BCa tissues, their combined siRNA-mediated knockdown might be more potent in decreasing BCa growth than the single inhibition of one target. Against each target two siRNAs were selected that specifically reduced the mRNA and protein levels of their appropriate target in EJ28 and J82 BCa cells. Inhibition of survivin provoked the strongest antiproliferative effect of all single target treatments, for example cell counts decreased by 50%. Simultaneous targeting of all four antiapoptotic genes downregulated expression levels of all targets and mediated significant reductions in cell viability and cell counts as well as induction of apoptosis. In EJ28 cells, combined knockdown of BCL2, Bcl-xL, XIAP and survivin caused a 2.5-fold enhancement in apoptosis rate and reduced cellular viability by 40%. Therefore, simultaneous knockdown of antiapoptotic BCL2, Bcl-xL, XIAP and survivin may represent a promising treatment option for bladder cancer.

Expression profile of WNT molecules in prostate cancer and its regulation by aminobisphosphonates

Skeletal metastases represent a frequent complication in patients with advanced prostate cancer (PCa) and often require bisphosphonate treatment to limit skeletal-related events. Metastasized PCa cells disturb bone remodeling. Since the WNT signaling pathway regulates bone remodeling and has been implicated in tumor progression and osteomimicry, we analyzed the WNT profile of primary PCa tissues and PCa cell lines and assessed its regulation by bisphosphonates. Prostate tissue (n = 18) was obtained from patients with benign prostate hyperplasia (BPH) and PCa patients with different disease stages. Serum samples were collected from 62 patients. Skeletal metastases were present in 17 patients of whom 6 had been treated with zoledronic acid. The WNT profile and its regulation by bisphoshonates were analyzed in tissue RNA extracts and serum samples as well as in osteotropic (PC3) and non-osteotropic (DU145, LNCaP) PCa cell lines. Several members of the WNT pathway, including WNT5A, FZD5, and DKK1 were highly up-regulated in PCa tissue from patients with advanced PCa. Interestingly, osteotropic cells showed a distinct WNT profile compared to non-osteotropic cells. While WNT5A, FZD5, and DKK1 were highly expressed in PC3 cells, WNT1 and SFRP1 mRNA levels were higher in DU145 cells. Moreover, zoledronic acid down-regulated mRNA levels of WNT5A (-34%), FZD5 (-60%), and DKK1 (-46%) in PC3 cells. Interestingly, patients with skeletal metastases who received zoledronic acid had twofold higher DKK1 serum levels compared to bisphosphonate-naive patients. The WNT signaling pathway is up-regulated in advanced PCa, differentially expressed in osteotropic versus non-osteotropic cells, and is regulated by zoledronic acid.