Pharmacological Activation of Nrf2 Enhances Functional Liver Regeneration.

BACKGROUND AND AIMS: The transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) regulates an array of cytoprotective genes, yet studies in transgenic mice have led to conflicting reports on its role in liver regeneration. We aimed to test the hypothesis that pharmacological activation of Nrf2 would enhance liver regeneration. APPROACH AND RESULTS: Wild-type and Nrf2 null mice were administered bardoxolone methyl (CDDO-Me), a potent activator of Nrf2 that has entered clinical development, and then subjected to two-thirds partial hepatectomy. Using translational noninvasive imaging techniques, CDDO-Me was shown to enhance the rate of restoration of liver volume (MRI) and improve liver function (multispectral optoacoustic imaging of indocyanine green clearance) in wild-type, but not Nrf2 null, mice following partial hepatectomy. Using immunofluorescence imaging and whole transcriptome analysis, these effects were found to be associated with an increase in hepatocyte hypertrophy and proliferation, the suppression of immune and inflammatory signals, and metabolic adaptation in the remnant liver tissue. Similar processes were modulated following exposure of primary human hepatocytes to CDDO-Me, highlighting the potential relevance of our findings to patients. CONCLUSIONS: Our results indicate that pharmacological activation of Nrf2 is a promising strategy for enhancing functional liver regeneration. Such an approach could therefore aid the recovery of patients undergoing liver surgery and support the treatment of acute and chronic liver disease.

Primary Tumor Resection is Associated with Improved Disease-Specific Mortality in Patients with Stage IV Small Intestinal Neuroendocrine Tumors (NETs): A Comparison of Upfront Surgical Resection Versus a Watch and Wait Strategy in Two Specialist NET Centers.

INTRODUCTION: Small intestinal neuroendocrine tumors (SI-NETs) often present with metastatic disease. An ongoing debate exists on whether to perform primary tumor resection (PTR) in patients with stage IV SI-NETs, without symptoms of the primary tumor and inoperable metastatic disease. OBJECTIVE: The aim of this study was to compare a treatment strategy of upfront surgical resection versus a surveillance strategy of watch and wait. METHODS: This was a retrospective cohort study of patients with stage IV SI-NETs at diagnosis, between 2000 and 2018, from two tertiary referral centers (Netherlands Cancer Institute [NKI] and Aintree University Hospital [AUH]) who had adopted contrasting treatment approaches: upfront surgical resection and watch and wait, respectively. Patients without symptoms related to the primary tumor were included. Multivariable intention-to-treat (ITT), per-protocol (PP), and instrumental variable (IV) analyses using 'institute' as an IV were performed to assess the influence of PTR on disease-specific mortality (DSM). RESULTS: A total of 557 patients were identified, with 145 patients remaining after exclusion of stage I-III disease or symptoms of the primary tumor (93 from the NKI and 52 from AUH). The cohorts differed in performance status (PS; p = 0.006) and tumor grade (p < 0.001). PTR was independently associated with reduced DSM irrespective of statistical methods employed: ITT hazard ratio [HR] 0.60, p = 0.005; PP HR 0.58, p < 0.001; and IV HR 0.07, p = 0.019. Other factors associated with DSM were age, PS, high chromogranin A, and somatostatin analog treatment. CONCLUSION: Taking advantage of contrasting institutional treatment strategies, this study identified PTR as an independent predictor of DSM. Future prospective studies should aim to validate these results.

Surgical management of suspected gallbladder cancer: The role of intraoperative frozen section for diagnostic confirmation.

BACKGROUND: Preoperative diagnosis for suspected gallbladder cancers is challenging, with a risk of overtreating benign disease, for example, xanthogranulomatous cholecystitis, with radical cholecystectomies. We retrospectively evaluated the surgeon's intraoperative assessment alone, and with the addition of intraoperative frozen sections, for suspected gallbladder cancers from a tertiary hepatobiliary multidisciplinary team (MDT). METHODS: MDT patients with complex gallbladder disease were included. Collated data included demographics, MDT discussion, operative details, and patient outcomes. RESULTS: A total of 454 patients with complex gallbladder disease were reviewed, 48 (10.6%) were offered radical surgery for suspected cancer. Twenty-five underwent frozen section that led to radical surgery in 6 (25%). All frozen sections were congruent with final histopathology but doubled the operating time (p < 0.0001). Both the surgeon's subjective and additional frozen section's objective assessment, allowed for de-escalation of unnecessary radical surgery, comparing favourably to a 13.0% cancer diagnosis among radical surgery historically. CONCLUSIONS: The MDT process was highly sensitive in identifying gallbladder cancers but lacked specificity. The surgeon's intraoperative assessment is paramount in suspected cancers, and deescalated unnecessary radical surgery. Intraoperative frozen section was a safe and viable adjunct at a cost of resources and operative time.

Prognosis and Circumferential Margin in Patients with Resected Hilar Cholangiocarcinoma.

BACKGROUND: Resection margin status is a known prognosticator in patients who undergo resection for hilar cholangiocarcinoma. However, the influence of an isolated positive circumferential margin on clinical outcome is unclear. METHODS: Patients with resected de novo hilar cholangiocarcinoma from two European hepatobiliary centres (Medical University of Vienna and Aintree University Hospital, 2006-2016) were classified according to resection margin status (negative, surgically positive, isolated circumferentially positive) and investigated with respect to overall survival (OS), recurrence-free survival (RFS) and recurrence pattern. RESULTS: Eighty-three (48 male/35 female) patients were enrolled. The median age was 64 years (range 33-80). The median follow-up was 21.7 months (range 0.3-92.4). Forty (48%) patients had negative resection margins, 25 (30%) had an isolated positive circumferential margin and 18 (22%) had a positive surgical margin. The 5-year OS rates in patients with negative, isolated positive circumferential and positive surgical resection margins were 47%, 33% and 0%, respectively. Median OS was 45.6, 32.7 and 14.5 months, respectively (log rank, P = 0.011). Upon multivariable Cox regression analysis, resection margin status and lymph node status remained statistically significant (P < 0.05). No difference with respect to RFS and recurrence pattern was found between the groups (P > 0.05). CONCLUSION: Our data show that these three resection margin types were associated with different clinical outcomes. Circumferential margin status may therefore serve as a novel prognostic biomarker.

Preoperative Leucocyte-Based Inflammatory Scores in Patients with Colorectal Liver Metastases: Can We Count on Them?

BACKGROUND: Neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR) and lymphocyte-to-monocyte ratio (LMR) have been identified as potential prognostic factors for overall survival (OS) in primary colorectal cancer, and there is a growing interest in their use in colorectal liver metastases (CLMs). However, optimal cut-off values for these ratios have not been defined by making comparison between series difficult. This study aimed to confirm the prognostic value of inflammatory scores in patients undergoing resection for CLM. METHODS: We retrospectively analysed data from 376 consecutive patients who underwent liver surgery for CLM between June 2010 and August 2015. We assessed the reproducibility of previously published ratios and determined new cut-off values using the Cut-off Finder web-based tool. Relations between cut-off values and OS were analysed with Kaplan-Meier log-rank survival analysis and multivariate Cox models. RESULTS: Three hundred and forty-three patients had full preoperative blood tests for calculation of NLR, PLR and LMR. The number of cut-off values which showed a significant discrimination for OS was 49/249 (19.7%) for NLR, 28/316 (8.9%) for PLR and 22/214 (10.3%) for LMR, all with a scattered nonlinear distribution. CONCLUSIONS: This study showed that inflammatory scores expressed as ratios do not seem to be consistently reliable prognostic markers in patients with resectable CLM.

Characterisation of the NRF2 transcriptional network and its response to chemical insult in primary human hepatocytes: implications for prediction of drug-induced liver injury.

The transcription factor NRF2, governed by its repressor KEAP1, protects cells against oxidative stress. There is interest in modelling the NRF2 response to improve the prediction of clinical toxicities such as drug-induced liver injury (DILI). However, very little is known about the makeup of the NRF2 transcriptional network and its response to chemical perturbation in primary human hepatocytes (PHH), which are often used as a translational model for investigating DILI. Here, microarray analysis identified 108 transcripts (including several putative novel NRF2-regulated genes) that were both downregulated by siRNA targeting NRF2 and upregulated by siRNA targeting KEAP1 in PHH. Applying weighted gene co-expression network analysis (WGCNA) to transcriptomic data from the Open TG-GATES toxicogenomics repository (representing PHH exposed to 158 compounds) revealed four co-expressed gene sets or 'modules' enriched for these and other NRF2-associated genes. By classifying the 158 TG-GATES compounds based on published evidence, and employing the four modules as network perturbation metrics, we found that the activation of NRF2 is a very good indicator of the intrinsic biochemical reactivity of a compound (i.e. its propensity to cause direct chemical stress), with relatively high sensitivity, specificity, accuracy and positive/negative predictive values. We also found that NRF2 activation has lower sensitivity for the prediction of clinical DILI risk, although relatively high specificity and positive predictive values indicate that false positive detection rates are likely to be low in this setting. Underpinned by our comprehensive analysis, activation of the NRF2 network is one of several mechanism-based components that can be incorporated into holistic systems toxicology models to improve mechanistic understanding and preclinical prediction of DILI in man.

Critical research gaps and recommendations to inform research prioritisation for more effective prevention and improved outcomes in colorectal cancer.

OBJECTIVE: Colorectal cancer (CRC) leads to significant morbidity/mortality worldwide. Defining critical research gaps (RG), their prioritisation and resolution, could improve patient outcomes. DESIGN: RG analysis was conducted by a multidisciplinary panel of patients, clinicians and researchers (n=71). Eight working groups (WG) were constituted: discovery science; risk; prevention; early diagnosis and screening; pathology; curative treatment; stage IV disease; and living with and beyond CRC. A series of discussions led to development of draft papers by each WG, which were evaluated by a 20-strong patient panel. A final list of RGs and research recommendations (RR) was endorsed by all participants. RESULTS: Fifteen critical RGs are summarised below: RG1: Lack of realistic models that recapitulate tumour/tumour micro/macroenvironment; RG2: Insufficient evidence on precise contributions of genetic/environmental/lifestyle factors to CRC risk; RG3: Pressing need for prevention trials; RG4: Lack of integration of different prevention approaches; RG5: Lack of optimal strategies for CRC screening; RG6: Lack of effective triage systems for invasive investigations; RG7: Imprecise pathological assessment of CRC; RG8: Lack of qualified personnel in genomics, data sciences and digital pathology; RG9: Inadequate assessment/communication of risk, benefit and uncertainty of treatment choices; RG10: Need for novel technologies/interventions to improve curative outcomes; RG11: Lack of approaches that recognise molecular interplay between metastasising tumours and their microenvironment; RG12: Lack of reliable biomarkers to guide stage IV treatment; RG13: Need to increase understanding of health related quality of life (HRQOL) and promote residual symptom resolution; RG14: Lack of coordination of CRC research/funding; RG15: Lack of effective communication between relevant stakeholders. CONCLUSION: Prioritising research activity and funding could have a significant impact on reducing CRC disease burden over the next 5 years.

Validation of clinical prognostic scores for patients treated with curative-intent for recurrent colorectal liver metastases.

BACKGROUND: Scoring systems were developed to stratify patients with colorectal liver metastases considered for liver resection into different risk groups. Such scores have never been evaluated in recurrent liver metastases. The aim of this study was to evaluate whether these scores are applicable to patients with recurrent colorectal liver metastases and treated with curative intent. METHODS: We retrospectively analyzed data from 375 consecutive patients who underwent liver surgery for colorectal liver metastases between June 2010 and August 2015. Seventy-three patients developed liver-limited recurrence treated with curative intent. The predictive value of 6 scores (Fong, Sofocleous, Nagashima, Nordlinger, Konopke, and the Basingstoke index) was assessed in this set of patients. RESULTS: Median follow-up was 36.2 months. Overall survival and progression-free survival were 33.6 and 5.6 months, respectively. When scores were applied for OS, none showed a significant stratification between patients, although Nagashima's score showed a significant difference in overall survival between patients from the low-risk group and those from the intermediate- and high-risk groups (40.8 vs 30.5 months, P = 0.039). For PFS, only Fong's score showed a statistically significant stratification (6.6 vs 4.7 months, P = 0.027). CONCLUSION: Scoring systems are of limited-value in stratifying patients operated on for recurrent colorectal liver metastases.

Phenotypic and functional analyses show stem cell-derived hepatocyte-like cells better mimic fetal rather than adult hepatocytes.

BACKGROUND & AIMS: Hepatocyte-like cells (HLCs), differentiated from pluripotent stem cells by the use of soluble factors, can model human liver function and toxicity. However, at present HLC maturity and whether any deficit represents a true fetal state or aberrant differentiation is unclear and compounded by comparison to potentially deteriorated adult hepatocytes. Therefore, we generated HLCs from multiple lineages, using two different protocols, for direct comparison with fresh fetal and adult hepatocytes. METHODS: Protocols were developed for robust differentiation. Multiple transcript, protein and functional analyses compared HLCs to fresh human fetal and adult hepatocytes. RESULTS: HLCs were comparable to those of other laboratories by multiple parameters. Transcriptional changes during differentiation mimicked human embryogenesis and showed more similarity to pericentral than periportal hepatocytes. Unbiased proteomics demonstrated greater proximity to liver than 30 other human organs or tissues. However, by comparison to fresh material, HLC maturity was proven by transcript, protein and function to be fetal-like and short of the adult phenotype. The expression of 81% phase 1 enzymes in HLCs was significantly upregulated and half were statistically not different from fetal hepatocytes. HLCs secreted albumin and metabolized testosterone (CYP3A) and dextrorphan (CYP2D6) like fetal hepatocytes. In seven bespoke tests, devised by principal components analysis to distinguish fetal from adult hepatocytes, HLCs from two different source laboratories consistently demonstrated fetal characteristics. CONCLUSIONS: HLCs from different sources are broadly comparable with unbiased proteomic evidence for faithful differentiation down the liver lineage. This current phenotype mimics human fetal rather than adult hepatocytes.