A panel of systemic inflammatory response biomarkers for outcome prediction in patients treated with radical cystectomy for urothelial carcinoma.

OBJECTIVES: To determine the predictive and prognostic value of a panel of systemic inflammatory response (SIR) biomarkers relative to established clinicopathological variables in order to improve patient selection and facilitate more efficient delivery of peri-operative systemic therapy. MATERIALS AND METHODS: The preoperative serum levels of a panel of SIR biomarkers, including albumin-globulin ratio, neutrophil-lymphocyte ratio, De Ritis ratio, monocyte-lymphocyte ratio and modified Glasgow prognostic score were assessed in 4199 patients treated with radical cystectomy for clinically non-metastatic urothelial carcinoma of the bladder. Patients were randomly divided into a training and a testing cohort. A machine-learning-based variable selection approach (least absolute shrinkage and selection operator regression) was used for the fitting of several multivariable predictive and prognostic models. The outcomes of interest included prediction of upstaging to carcinoma invading bladder muscle (MIBC), lymph node involvement, pT3/4 disease, cancer-specific survival (CSS) and recurrence-free survival (RFS). The discriminatory ability of each model was either quantified by area under the receiver-operating curves or by the C-index. After validation and calibration of each model, a nomogram was created and decision-curve analysis was used to evaluate the clinical net benefit. RESULTS: For all outcome variables, at least one SIR biomarker was selected by the machine-learning process to be of high discriminative power during the fitting of the models. In the testing cohort, model performance evaluation for preoperative prediction of lymph node metastasis, ≥pT3 disease and upstaging to MIBC showed a 200-fold bootstrap-corrected area under the curve of 67.3%, 73% and 65.8%, respectively. For postoperative prognosis of CSS and RFS, a 200-fold bootstrap corrected C-index of 73.3% and 72.2%, respectively, was found. However, even the most predictive combinations of SIR biomarkers only marginally increased the discriminative ability of the respective model in comparison to established clinicopathological variables. CONCLUSION: While our machine-learning approach for fitting of the models with the highest discriminative ability incorporated several previously validated SIR biomarkers, these failed to improve the discriminative ability of the models to a clinically meaningful degree. While the prognostic and predictive value of such cheap and readily available biomarkers warrants further evaluation in the age of immunotherapy, additional novel biomarkers are still needed to improve risk stratification.

Preoperative plasma level of endoglin as a predictor for disease outcomes after radical cystectomy for nonmetastatic urothelial carcinoma of the bladder.

Elevated preoperative plasma level of endoglin has been associated with worse oncologic outcomes in various malignancies. The present large-scale study aimed to determine the predictive and prognostic values of preoperative endoglin with regard to clinicopathologic and survival outcomes in patients treated with radical cystectomy (RC) for nonmetastatic urothelial carcinoma of the bladder (UCB). We prospectively collected preoperative blood samples from 1036 consecutive patients treated with RC for UCB. Logistic and Cox regression analyses were undertaken to assess the correlation of endoglin levels with pathologic and survival outcomes, respectively. The AUC and C-index were used to assess the discrimination. Patients with adverse pathologic features had significantly higher median preoperative endoglin plasma levels than their counterparts. Higher preoperative endoglin level was independently associated with an increased risk for lymph node metastasis, ≥pT3 disease, and nonorgan confined disease (NOCD; all p < 0.001). Plasma endoglin level was also independently associated with cancer-specific and overall survival in both pre- and postoperative models (all p < 0.05), as well as with recurrence-free survival (RFS) in the preoperative model (p < 0.001). The addition of endoglin to the preoperative standard model improved its discrimination for prediction of lymph node metastasis, ≥pT3 disease, NOCD, and RFS (differential increases in C-indices: 10%, 5%, 5.8%, and 4%, respectively). Preoperative plasma endoglin is associated with features of biologically and clinically aggressive UCB as well as survival outcomes. Therefore, it seems to hold the potential of identifying UCB patients who may benefit from intensified therapy in addition to RC such as extended lymphadenectomy or/and preoperative systemic therapy.

Impact of the preoperative modified Glasgow Prognostic Score on disease outcome after radical cystectomy for urothelial carcinoma of the bladder.

BACKGROUND: To investigate the predictive and prognostic value of the preoperative modified Glasgow Prognostic Score (mGPS) in patients with urothelial carcinoma of the bladder (UCB) treated with radical cystectomy (RC). METHODS: We conducted a retrospective analysis of an established multicenter database consisting of 4335 patients who were treated with RC±adjuvant chemotherapy for UCB between 1979 and 2012. The mGPS of each patient was calculated on the basis of preoperative serum C-reactive protein and albumin. Uni- and multivariable logistic and Cox regression analyses were performed. The discriminatory ability of the models was assessed by calculating the area under receiver operating characteristics curves (AUC) and concordance-indices (C-Index). The additional clinical net-benefit was assessed using the decision curve analysis (DCA). RESULTS: A mGPS of 0, 1, and 2 was observed in 3,158 (72.8%), 1,020 (23.5%), and 157 (3.6%) patients, respectively. On multivariable logistic regression analyses, mGPS of 1 or 2 were associated with an increased risk of pT3/4 disease at RC (OR 1.25, P=0.004 and OR 2.58, SP<0.001, respectively) and/or lymph node metastasis (OR 1.7, P<0.001 and OR 3.9, P<0.001, respectively). Addition of the mGPS to a predictive model based on preoperatively available variables improved its accuracy for prediction of lymph node metastasis (change of AUC +3.7%, P<0.001). On multivariable Cox regression analyses, mGPS of 1 or 2 remained associated with worse recurrence-free survival (HR 1.14, P=0.03 and HR 1.89 P<0.001, respectively), cancer-specific survival (HR 1.16, P=0.032 and HR 2.1, P<0.001, respectively) and overall survival (HR 1.5, P=0.007 and HR 1.92 P<0.001, respectively) compared to mGPS of 0. The additional discriminatory ability of the mGPS for prognosis of survival outcomes in separate models that included either established pre- or postoperative variables did not improve the C-Index by a prognostically relevant degree (change of C-Index <2% for all models). On DCA, the inclusion of the mGPS did not meaningfully improve the net-benefit for clinical decision-making regarding survival outcomes. CONCLUSIONS: We confirmed that an elevated mGPS is an independent risk factor for non-organ confined disease and poor survival outcomes in patients with UCB undergoing RC. However, the mGPS showed little value in improving the discriminatory ability of predictive and prognostic models that relied on either pre- or postoperative clinicopathological variables. The discriminatory ability of this biomarker in the age of immunotherapy warrants further evaluation.

Accuracy of Frozen Section Analysis of Urethral and Ureteral Margins During Radical Cystectomy for Bladder Cancer: A Systematic Review and Diagnostic Meta-Analysis.

CONTEXT: The question of the ability of frozen section analysis (FSA) to accurately detect malignant pathology intraoperatively has been discussed for many decades. OBJECTIVE: We aimed to conduct a systematic review and meta-analysis assessing the diagnostic estimates of FSA of the urethral and ureteral margins in patients treated with radical cystectomy (RC) for bladder cancer (BCa). EVIDENCE ACQUISITION: The MEDLINE and EMBASE databases were searched in February 2021 for studies analyzing the association between FSA and the final urethral and ureteral margin status in patients treated with RC for BCa. The primary endpoint was the value of pathologic detection of urethral and ureteral malignant involvement with FSA during RC compared with the final margin status. We included studies that provided true positive, true negative, false positive, and false negative values for FSA, which allowed us to calculate the diagnostic estimates. EVIDENCE SYNTHESIS: Fourteen studies, comprising 8208 patients, were included in the quantitative synthesis. Forest plots revealed that the pooled sensitivity and specificity for FSA of urethral margins during RC were 0.83 (95% confidence interval [CI] 0.38-0.97) and 0.95 (95% CI 0.91-0.97), respectively. While for the FSA of ureteral margins, the pooled sensitivity and specificity were 0.77 (95% CI 0.67-0.84) and 0.97 (95% CI 0.95-0.98), respectively. Calculated diagnostic odds ratios indicated high FSA effectiveness, and patients with a positive urethral or ureteral margin at final pathology are over 100 times more likely to have positive FSA than patients without margin involvement at final pathology. Area under the curves of 96.6% and 96.7% were reached for FSA detection of urethral and ureteral tumor involvement, respectively. CONCLUSIONS: Intraoperative FSA demonstrated high diagnostic performance in detecting both urethral and ureteral malignant involvement at the time of RC for BCa. FSA of both urethral and ureteral margins during RC is accurate enough to be of great value in the routine management of BCa patients treated with RC. While its specificity was great to guide intraoperative decision-making, its sensitivity remains suboptimal yet. PATIENT SUMMARY: We believe that the frozen section analysis of both urethral and ureteral margins during radical cystectomy should be considered more often in urologic practice, until quality of life-based cost-effectiveness studies can identify patients within each institution who are unlikely to benefit from it.

Discordance Between Clinical and Pathological Staging and Grading in Upper Tract Urothelial Carcinoma.

INTRODUCTION: This study aimed to evaluate the concordance in tumor stage and grade between ureteroscopic (URS) biopsy and radical nephroureterectomy (RNU) in patients with upper tract urothelial carcinoma (UTUC). PATIENTS AND METHODS: Records of 1,214 UTUC patients who had undergone URS biopsy followed by RNU were included. Univariable and multivariable logistic regression analyses were performed to identify factors contributing to the pathological upstaging. RESULTS: The concordance between URS biopsy-based clinical and RNU pathological staging was 34.5%. Clinical understaging occurred in 59.5% patients. Upstaging to muscle-invasive disease occurred in 240 (41.7%) of 575 patients diagnosed with ≤cT1 disease. Of those diagnosed with muscle-invasive disease on final pathology, 89.6% had been clinically diagnosed with ≤cT1 disease. In the univariable analyses, computed tomography urography (CTU)-based invasion, ureter location, hydronephrosis, high-grade cytology, high-grade biopsy, sessile architecture, age, and women sex were significantly associated with pathological upstaging (P < .05). In the multivariable analyses, CTU-based invasion and hydronephrosis remained associated with pathological upstaging (P < .05). URS biopsy-based clinical and pathological gradings were concordant in 634 (54.2%) patients. Clinical undergrading occurred in 496 (42.4%) patients. CONCLUSIONS: Clinical understaging/undergrading and upstaging to muscle-invasive disease occurred in a high proportion of UTUC patients undergoing RNU. Despite the inherent selection bias, these data underline the challenges of accurate UTUC staging and grading. In daily clinical practice, URS biopsy and CTU offer the most accurate preoperative information albeit with limited predictive value when used alone. These findings should be considered when utilizing preoperative, risk-adapted strategies.

Impact of preoperative systemic immune-inflammation Index on oncologic outcomes in bladder cancer patients treated with radical cystectomy.

PURPOSE: To investigate the predictive and prognostic value of the preoperative systemic immune-inflammation index (SII) in patients undergoing radical cystectomy (RC) for clinically non-metastatic urothelial cancer of the bladder (UCB). METHODS: Overall, 4,335 patients were included, and the cohort was stratified in two groups according to SII using an optimal cut-off determined by the Youden index. Uni- and multivariable logistic and Cox regression analyses were performed, and the discriminatory ability by adding SII to a reference model based on available clinicopathologic variables was assessed by area under receiver operating characteristics curves (AUC) and concordance-indices. The additional clinical net-benefit was assessed using decision curve analysis (DCA). RESULTS: High SII was observed in 1879 (43%) patients. On multivariable preoperative logistic regression, high SII was associated with lymph node involvement (LNI; P = 0.004), pT3/4 disease (P <0.001), and non-organ confined disease (NOCD; P <0.001) with improvement of AUCs for predicting LNI (P = 0.01) and pT3/4 disease (P = 0.01). On multivariable Cox regression including preoperative available clinicopathologic values, high SII was associated with recurrence-free survival (P = 0.028), cancer-specific survival (P = 0.005), and overall survival (P = 0.006), without improvement of concordance-indices. On DCAs, the inclusion of SII did not meaningfully improve the net-benefit for clinical decision-making in all models. CONCLUSION: High preoperative SII is independently associated with pathologic features of aggressive disease and worse survival outcomes. However, it did not improve the discriminatory margin of a prediction model beyond established clinicopathologic features and failed to add clinical benefit for decision making. The implementation of SII as a part of a panel of biomarkers in future studies might improve decision-making.

Incidence, risk factors and outcomes of urethral recurrence after radical cystectomy for bladder cancer: A systematic review and meta-analysis.

We aimed to conduct a systematic review and meta-analysis assessing the incidence and risk factors of urethral recurrence (UR) as well as summarizing data on survival outcomes in patients with UR after radical cystectomy (RC) for bladder cancer. The MEDLINE and EMBASE databases were searched in February 2021 for studies of patients with UR after RC. Incidence and risk factors of UR were the primary endpoints. The secondary endpoint was survival outcomes in patients who experienced UR. Twenty-one studies, comprising 9,435 patients, were included in the quantitative synthesis. Orthotopic neobladder (ONB) diversion was associated with a decreased probability of UR compared to non-ONB (pooled OR: 0.44, 95% CI: 0.31-0.61, P < 0.001) and male patients had a significantly higher risk of UR compared to female patients (pooled OR: 3.16, 95% CI: 1.83-5.47, P < 0.001). Among risk factors, prostatic urethral or prostatic stromal involvement (pooled HR: 5.44, 95% CI: 3.58-8.26, P < 0.001; pooled HR: 5.90, 95% CI: 1.82-19.17, P = 0.003, respectively) and tumor multifocality (pooled HR: 2.97, 95% CI: 2.05-4.29, P < 0.001) were associated with worse urethral recurrence-free survival. Neither tumor stage (P = 0.63) nor CIS (P = 0.72) were associated with worse urethral recurrence-free survival. Patients with UR had a 5-year CSS that varied from 47% to 63% and an OS - from 40% to 74%; UR did not appear to be related to worse survival outcomes. Male patients treated with non-ONB diversion as well as patients with prostatic involvement and tumor multifocality seem to be at the highest risk of UR after RC. Risk-adjusted standardized surveillance protocols should be developed into clinical practice after RC.

Psychometric validation of the European Organisation for Research and Treatment of Cancer-Quality of Life Questionnaire Sexual Health (EORTC QLQ-SH22).

BACKGROUND: The European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Group developed a questionnaire to assess sexual health in patients with cancer and cancer survivors. This study evaluates the psychometric properties of the questionnaire. METHODS: The 22-item EORTC sexual health questionnaire (EORTC QLQ-SH22) was administered with the EORTC QLQ-C30 to 444 patients with cancer. The hypothesised scale structure, reliability and validity were evaluated through standardised psychometric procedures. RESULTS: The cross-cultural field study showed that the majority of patients (94.7%) were able to complete the QLQ-SH22 in less than 20 min; 89% of the study participants did not need any help to fill in the questionnaire. Multi-item multi-trait scaling analysis confirmed the hypothesised scale structure with two multi-item scales (sexual satisfaction, sexual pain) and 11 single items (including five conditional items and four gender-specific items). The internal consistency yielded acceptable Cronbach's alpha coefficients (.90 for the sexual satisfaction scale, .80 for the sexual pain scale). The test-retest correlations (Pearson's r) ranged from .70 to .93 except for the scale communication with professionals (.67) and male body image (.69). The QLQ-SH22 discriminates well between subgroups of patients differing in terms of their performance and treatment status. CONCLUSION: The study supports the reliability, the content and construct validity of the QLQ-SH22. The newly developed questionnaire is clinically applicable to assess sexual health of patients with cancer at different treatment stages and during survivorship for clinical trials and for clinical practice.

Health-related quality of life in bladder cancer patients: general and cancer-specific instruments. Part 1.

PURPOSE OF REVIEW: Although survival outcomes are the primary outcomes to determine the effectiveness of treatment options, quality of life (QoL) is gaining in importance in addition to classic oncological outcomes. The present review aims to state and critically assess the challenges in health-related QoL (HRQoL) assessment especially in bladder cancer (BC) patients. RECENT FINDINGS: General QoL-instruments do not address concerns specific to cancer patients or BC patients. Domains, such as sexual functioning, embarrassment, self-consciousness, psychological distress, and urinary incontinence, are not adequately covered by any of the available instruments. With these QoL-instruments becoming increasingly specialized, the general aspects of QoL and possible unanticipated adverse effects are no longer likely to be accurately assessed. Sex-specific requirements have not been properly addressed by these QoL-instruments. HRQoL is reported to be lower in the elderly population, which may be due to their associated comorbidities and limitations, rather than treatment-related issues. SUMMARY: Due to their specifications, BC-specific instruments need to be used together with general QoL instruments to assess overall well being and disease- and treatment-specific QoL. Assessment of age-specific HRQoL is essential to understanding the QoL burden in each age group. QoL assessment calls for more detailed sex-specific questions to accurately address the HRQoL dimensions in men and women alike.

Health-related quality of life in bladder cancer patients: bladder cancer-specific instruments and domains. Part 2.

PURPOSE OF REVIEW: Several instruments have been designed to evaluate health-related quality of life (HRQoL) in patients with bladder cancer (BC). However, they vary in purpose, domains, and quality. To identify QoL instruments that have been validated for BC patients and to critically assess their domains and limitations. RECENT FINDINGS: Of the 11 instruments identified, seven have been externally validated. Of these, four can be used across all disease states; two are available for QoL assessment in patients with non-muscle invasive bladder cancer (NMIBC); and the European Organisation for Research and Treatment of Cancer (EORTC) module is intended for use together with a generic cancer-specific tool. Of the three instruments available to assess QoL in patients with muscle invasive bladder cancer (MIBC), EORTC Quality of Life Questionnaire-Bladder Cancer Muscle Invasive30 (QLQ-BLM30) and Functional Assessment of Cancer Therapy-Bladder-Cystectomy (FACT-Bl-Cys) need to be used each with their respective generic core questionnaire, whereas Ileal Orthotopic Neobladder-Pro Questionnaire is intended only to evaluate patients who have received an orthotopic neobladder.The core domains assessed by these instruments include social functioning, mental health, physical function, urinary function and sexual function. SUMMARY: No optimal BC-specific QoL instruments exist. Multiple cancer- and BC-specific instruments are required to cover each of the relevant domains. Selected tools should be reviewed within the context of specific research objectives.

Role of systemic immune-inflammation index in patients treated with salvage radical prostatectomy.

PURPOSE: To examine the predictive and prognostic value of preoperative Systemic Immune-inflammation Index (SII) in patients with radio-recurrent prostate cancer (PCa) treated with salvage radical prostatectomy (SRP). MATERIALS AND METHODS: This multicenter retrospective study included 214 patients with radio-recurrent PCa, treated with SRP between 2007 and 2015. SII was measured preoperatively (neutrophils × platelets/lymphocytes) and the cohort was stratified using optimal cut-off. Uni- and multivariable logistic and Cox regression analyses were performed to evaluate the predictive and prognostic value of SII as a preoperative biomarker. RESULTS: A total of 81 patients had high preoperative SII (≥ 730). On multivariable logistic regression modeling, high SII was predictive for lymph node metastases (OR 3.32, 95% CI 1.45-7.90, p = 0.005), and non-organ confined disease (OR 2.55, 95% CI 1.33-4.97, p = 0.005). In preoperative regression analysis, high preoperative SII was an independent prognostic factor for cancer-specific survival (CSS; HR 10.7, 95% CI 1.12-103, p = 0.039) and overall survival (OS; HR 8.57, 95% CI 2.70-27.2, p < 0.001). Similarly, in postoperative multivariable models, SII was associated with worse CSS (HR 22.11, 95% CI 1.23-398.12, p = 0.036) and OS (HR 5.98, 95% CI 1.67-21.44, p = 0.006). Notably, the addition of SII to preoperative reference models improved the C-index for the prognosis of CSS (89.5 vs. 80.5) and OS (85.1 vs 77.1). CONCLUSIONS: In radio-recurrent PCa patients, high SII was associated with adverse pathological features at SRP and survival after SRP. Preoperative SII could help identify patients who might benefit from novel imaging modalities, multimodal therapy or a closer posttreatment surveillance.

Activation of the Nrf2-ARE pathway by the Alternaria alternata mycotoxins altertoxin I and II.

The mycotoxins altertoxin I and II (ATX I and II) are secondary metabolites produced by Alternaria alternata fungi and may occur as food and feed contaminants, especially after long storage periods. Although the toxic potential of altertoxins has been previously investigated, little is known about the pathways that play a role in their intracellular metabolism. In order to identify potential targets of ATX I and ATX II, the two toxins were tested for interaction with the nuclear factor erythroid-derived 2-like 2/antioxidant response element (Nrf2/ARE) pathway in mammalian cells. This pathway can be activated by various stressors resulting in the expression of enzymes important for metabolism and detoxification. In the present study, only ATX II triggered a concentration-dependent increase in Nrf2-ARE-dependent luciferase expression. Consistently, confocal microscopy revealed an ATX II-induced increase in Nrf2 signal in HT29 intestinal cells. In agreement with these data, ATX II induced the transcription of γ-glutamate cysteine ligase, the key enzyme in catalyzing GSH synthesis of the cells and which is regulated by Nrf2. Further investigations demonstrated that ATX II induced a concentration-dependent depletion of the cellular GSH levels after short incubation time (3 h) and an increase after longer incubation time (24 h). In conclusion, it was demonstrated that ATX II can interact at several levels of the Nrf2-ARE pathway in mammalian cells and that ATX I does not share the same mechanism of action.

Impact of phase I metabolism on uptake, oxidative stress and genotoxicity of the emerging mycotoxin alternariol and its monomethyl ether in esophageal cells.

Studies on the genotoxicity of Alternaria mycotoxins focus primarily on the native compounds. Alternariol (AOH) and its methyl ether (AME) have been reported to represent substrates for cytochrome P450 enzymes, generating hydroxylated metabolites. The impact of these phase I metabolites on genotoxicity remains unknown. In the present study, the synthesis and the toxicological effects of the metabolites 4-hydroxy alternariol (4-OH-AOH) and 4-hydroxy alternariol monomethyl ether (4-OH-AME) are presented and compared to the effects of the parent molecules. Although the two phase I metabolites contain a catecholic structure, which is expected to be involved in redox cycling, only 4-OH-AOH increased reactive oxygen species (ROS) in human esophageal cells (KYSE510), 4 times more pronounced than AOH. No ROS induction was observed for 4-OH-AME, although the parent compound showed some minor impact. Under cell-free conditions, both metabolites inhibited topoisomerase II activity comparable to their parent compounds. In KYSE510 cells, both metabolites were found to enhance the level of transient DNA-topoisomerase complexes in the ICE assay. Although the level of ROS was significantly increased by 4-OH-AOH, neither DNA strand breaks nor enhanced levels of formamidopyrimidine-DNA-glycosylase (FPG)-sensitive sites were observed. In contrast, AOH induced significant DNA damage in KYSE510 cells. Less pronounced or even absent effects of hydroxylated metabolites compared to the parent compounds might at least partly be explained by their poor cellular uptake. Glucuronidation as well as sulfation appear to have only a minor influence. Instead, methylation of 4-OH-AOH seems to be the preferred way of metabolism in KYSE510 cells, whereby the toxicological relevance of the methylation product remains to be clarified.

Plumericin inhibits proliferation of vascular smooth muscle cells by blocking STAT3 signaling via S-glutathionylation.

The etiology of atherosclerosis and restenosis involves aberrant inflammation and proliferation, rendering compounds with both anti-inflammatory and anti-mitogenic properties as promising candidates for combatting vascular diseases. A recent study identified the iridoid plumericin as a new scaffold inhibitor of the pro-inflammatory NF-κB pathway in endothelial cells. We here examined the impact of plumericin on the proliferation of primary vascular smooth muscle cells (VSMC). Plumericin inhibited serum-stimulated proliferation of rat VSMC. It arrested VSMC in the G1/G0-phase of the cell cycle accompanied by abrogated cyclin D1 expression and hindered Ser 807/811-phosphorylation of retinoblastoma protein. Transient depletion of glutathione by the electrophilic plumericin led to S-glutathionylation as well as hampered Tyr705-phosphorylation and activation of the transcription factor signal transducer and activator of transcription 3 (Stat3). Exogenous addition of glutathione markedly prevented this inhibitory effect of plumericin on Stat3. It also overcame downregulation of cyclin D1 expression and the reduction of biomass increase upon serum exposure. This study revealed an anti-proliferative property of plumericin towards VSMC which depends on plumericin's thiol reactivity and S-glutathionylation of Stat3. Hence, plumericin, by targeting at least two culprits of vascular dysfunction -inflammation and smooth muscle cell proliferation -might become a promising electrophilic lead compound for vascular disease therapy.

Glucose availability is a decisive factor for Nrf2-mediated gene expression.

Activation of the transcription factor Nrf2 (nuclear factor-erythroid 2-related factor 2) is one of the major cellular defense lines against oxidative and xenobiotic stress, but also influences genes involved in lipid and glucose metabolism. It is unresolved whether the cytoprotective and metabolic responses mediated by Nrf2 are connected or separable events in non-malignant cells. In this study we show that activation of Nrf2, either by the small molecule sulforaphane or knockout of the Nrf2 inhibitor Keap1, leads to increased cellular glucose uptake and increased glucose addiction in fibroblasts. Upon Nrf2 activation glucose is preferentially metabolized through the pentose phosphate pathway with increased production of NADPH. Interference with the supply of glucose or the pentose phosphate pathway and NADPH generation not only hampers Nrf2-mediated detoxification of reactive oxygen species on the enzyme level but also Nrf2-initiated expression of antioxidant defense proteins, such as glutathione reductase and heme-oxygenase1. We conclude that the Nrf2-dependent protection against oxidative stress relies on an intact pentose phosphate pathway and that there is crosstalk between metabolism and detoxification already at the level of gene expression in mammalian cells.

Modulation of Nrf2-dependent gene transcription by bilberry anthocyanins in vivo.

In a human pilot intervention study (healthy + ileostomy probands), the questions were addressed whether in vivo consumption of an anthocyanin-rich bilberry (Vaccinium myrtillius L.) pomace extract (BE) affects (i) the transcription of Nrf2-dependent genes in peripheral blood mononuclear cells (PBMC), indicative for systemic effects, and (ii) the level of oxidative DNA damage in these cells. In healthy test subjects transcripts of NAD(P)H quinone oxidoreductase 1 (NQO1) were significantly elevated throughout the observation period (1-8 h), whereas transcription of heme oxygenase 1 (HO-1) and Nrf2 was significantly decreased. NQO1 and HO-1 transcription remained unchanged in the ileostomy probands, whereas Nrf2-transcription was suppressed in both groups. Decrease in oxidative DNA damage was observed 2 h after BE consumption again only in healthy subjects. In vitro studies using a reporter gene approach (CHO) and qPCR (HT29) indicate that not the intact anthocyanins/anthocyanidins are the activating constituents but the intestinal degradation product phloroglucinol aldehyde (PGA). Taken together, consumption of anthocyanin-rich BE was found to modulate Nrf2-dependent gene expression in PBMCs indicative for systemic activity. Limitation of the effect to healthy test subjects suggests a role of colonic processes for bioactivity, supported by the results on Nrf2-activating properties of the intestinal anthocyanin degradation product PGA.