Reply to: ''Network-based discovery of gene signature for vascular invasion prediction in HCC''

To the Editor:Liu and colleagues raise some issues regarding our recently pub-lished study [1] to which we would like to make the followingcomments. We acknowledge the limitations that a gene-expres-sion-based biomarker could have, and that our signature is notunique. Certainly, previous attempts to find such a signature havebeen published in the past [2]. We also know that, as in othergene expression studies, potential bias could occur. In fact,reported prognostic signatures are often not reproducible, inmost of the cases due to suboptimal study design, small samplesizes, and also because many of them have been based on retro-spectively collected tissue samples [3]. Even after taking intoaccount these sources of bias or inconsistencies, it so happensthat only a small minority of the reported signatures truly retainprognostic significance. In fact, our recent outcome analysisincluding 22 gene signatures with prognostic significance inHCC (18 from the tumor, and four from the non-tumoral adjacenttissue) showed that only two signatures retained independentprognostic value [4].In our work, we select a training cohort based upon a homo-geneous etiology to minimize the risk of molecular heterogene-ity and to identify a clean and distinct signature. Patients withHCV-related HCC were selected, since this is the most commonetiology in the Western countries. Then, we validate the signa-ture in an independent multi-etiologic cohort of patients andthe accuracy remained stable when an etiology-dependent sub-group analysis was performed [1]. The study was aimed at pro-viding a gene-set to ease the preoperative diagnosis of vascularinvasion, but was not designed for defining outcome prediction.Nonetheless, we have data indicating that the presence of a vas-cular invasion signature correlates with poor outcome, since thesignature was found to be associated with early recurrence(p = 0.057), and was enriched in patients sharing signatures ofpoor prognosis [4].Even considering that the question posed is simple (to identifya gene-signature capturing vascular invasion) the characteristicsof patients, sample collection, sampling issues, technical varia-tion, validation of results, and bioinformatics approaches are cer-tainly heterogeneous, and thus the results might vary. In mostinstances, however, the different signatures seem to be able tocapture common oncogenic mechanisms, as reflected by theircapacity to adequately allocate patients into a poor or good prog-nosis group [5]. By applying a different methodological approach(weighted gene co-expression network analysis) to our data, Liuet al. provide a 9-gene signature with similar accuracy and nooverlap with our 35-gene signature. The method applied is basedon systems biology to find clusters of highly correlated genesacross microarray samples, identify hubs of each module and cor-relate them with clinical traits [6]. This analysis is based on thehypothesis that information on signaling pathways is crucial tounderstand how genes are connected to each other and how theyinfluence cellular functions in both normal and cancer conditions.This result further underlines the need for integrating the vastamount of available data and the development of powerful bioin-formatics resources (annotation, methodologies, technical plat-forms, etc.).A more relevant question is when can our signature-alone orin combination with tumor size- be translated into clinical prac-tice. Strict rules have been proposed recently by Simon and col-leagues [7]. Following this proposal, the EASL-EORTC guidelineson management of HCC have outlined a list of requirements inorder to adopt molecular signatures in the clinical practice [8],which are as follows:1. First, the signature should be generated in the setting of ran-domized studies or in case of cohort studies, it should followthe training/validation approach.2. The signature should retain independent prognostic valuewhen tested along known clinico-pathological variables.3. The results should be confirmed by independent investigatorsin a separate set of samples.Thus, according to these rules, in order to implement our sig-nature in the decision-making process, for instance in the waitinglist of liver transplantation, it should be validated by independentinvestigators in a novel set of samples. Ideally, the signature hasto be reproduced in a device, which should give similar results.Only then, data is ready for acceptance in guidelines. It is a longpath, but the only one for translation of genomic results into ourpractice.Conflict of interestThe authors declared that they do not have anything to discloseregarding funding or conflict of interest with respect to thismanuscript.Reference

Foreword

Viral hepatitis; Liver cirrhosisHepatitis viral; Cirrosis del hígadoHepatitis viral; Cirrosi del fetg

Molecular function of the novel α7β2 nicotinic receptor

The α7 nicotinic receptor is a promising drug target for neurological and inflammatory disorders. Although it is the homomeric member of the family, a novel α7β2 heteromeric receptor has been discovered. To decipher the functional contribution of the β2 subunit, we generated heteromeric receptors with fixed stoichiometry by two different approaches comprising concatenated and unlinked subunits. Receptors containing up to three β2 subunits are functional. As the number of β2 subunits increases in the pentameric arrangement, the durations of channel openings and activation episodes increase progressively probably due to decreased desensitization. The prolonged activation episodes conform the kinetic signature of α7β2 and may have an impact on neuronal excitability. For activation of α7β2 receptors, an α7/α7 binding-site interface is required, thus indicating that the three β2 subunits are located consecutively in the pentameric arrangement. α7 positive allosteric modulators (PAMs) are emerging as novel therapeutic drugs. The presence of β2 in the pentamer affects neither type II PAM potentiation nor activation by an allosteric agonist whereas it impairs type I PAM potentiation. This first single-channel study provides fundamental basis required to decipher the role and function of the novel α7β2 receptor and opens doors to develop selective therapeutic drugs

Survival and adverse events of elderly patients treated with sorafenib for hepatocellular carcinoma

Elderly patients; Hepatocellular carcinoma; SorafenibPacientes ancianos; Carcinoma hepatocelular; SorafenibPacients grans; Carcinoma hepatocel·lular; SorafenibIntroduction: The first-line treatment for advanced hepatocellular carcinoma (HCC) is atezolizumab plus bevacizumab, but its availability is not universal and elderly patients are underrepresented in clinical trials. There is little evidence of efficacy and tolerability in elderly patients under systemic treatment. The aims of this study were to characterize the profile of elderly patients treated with sorafenib, assess their survival and safety profile in order to extrapolate their eligibility for systemic treatment. Methods: Retrospective multicentre study of HCC patients aged ≥75 years old treated with sorafenib from January 2008 to December 2019. Demographic data, baseline characteristics, and variables related to HCC and sorafenib were recorded. Overall survival (OS) and safety were analyzed. Results: The study included 206 patients from 11 hospitals, median age 77.9 years; 71.4% men and 62.6% stage Barcelona Clinic Liver Cancer- C (BCLC-C). The main causes of cirrhosis were hepatitis C (60.7%) and alcohol (14.7%). Most patients (84.5%) started with sorafenib 800mg and 15.5% at lower dosage. Arterial hypertension (AHT) (74.2 vs 62.2%; standardized mean differences (STD): 26) and baseline ECOG-PS>0 (45.3 vs 34.7%; STD: 38.2) differed significantly between patients receiving low and full doses. Median OS was 15.4 months (18.2 in BCLC-B vs 13.6 in BCLC-C). OS was not modified by comorbidities, age or period with more expertise. Conclusions: Sorafenib appears to be safe in elderly patients with HCC. This is the first study to characterize the profile of elderly patients to be considered for systemic treatment. These findings could be used as the reference profile for elderly candidates for atezolizumab-bevacizumab.AS: Travel grants from Tillots, Ferring, Norgine, Alfasigma, Jansen, Abbvie. MC: None. ZV: None. SM-M: None. VS: Travel grants from Bayer. Consultancy LEO Pharma. MP: None. LC: None. RG: None. AG: None. BM: Consultancy: Bayer-Shering Pharma, Eisai-Merck. Conferences/lectures: Eisai, MSD, Roche. Research grant: Lab Viñas. Funding: BM is funded by grants PI18/00961 and PI21/00714 from Instituto de Salud Carlos III. DH. None. AC. None. SM. Conferences/lectures: Bayer. Travel grants: Bayer, and Eisai. MRo. None. MRe. Consultancy: Bayer-Shering Pharma, BMS, Roche, Ipsen, AstraZeneca, Lilly. BTG/Paid conferences: Bayer-Shering Pharma, BMS, Gilead, Lilly. Research Grants: Bayer-Shering Pharma, Ipsen. MV. Travel grants: Gilead, MSD, Bayer, Abvie. Conferences/lectures: MSD, Gilead, Abvie, Eisai

Trans-arterial chemoembolization as a loco-regional inducer of immunogenic cell death in hepatocellular carcinoma: implications for immunotherapy

Immunotherapy; Liver neoplasmsInmunoterapia; Neoplasias hepáticasImmunoteràpia; Neoplàsies hepàtiquesBackground Modulation of adaptive immunity may underscore the efficacy of trans-arterial chemoembolization (TACE). We evaluated the influence of TACE on T-cell function by phenotypic lymphocyte characterization in samples of patients undergoing surgery with (T+) or without (T-) prior-TACE treatment. Methods We profiled intratumoral (IT), peritumoral (PT) and non-tumoral (NT) background tissue to evaluate regulatory CD4+/FOXP3+ (T-reg) and immune-exhausted CD8+/PD-1+ T-cells across T+ (n=58) and T− (n=61). We performed targeted transcriptomics and T-cell receptor sequencing in a restricted subset of samples (n=24) evaluated in relationship with the expression of actionable drivers of anti-cancer immunity including PD-L1, indoleamine 2,3 dehydrogenase (IDO-1), cytotoxic T-lymphocyte associated protein 4 (CTLA-4), Lag-3, Tim-3 and CD163. Results We analyzed 119 patients resected (n=25, 21%) or transplanted (n=94, 79%) for Child-Pugh A (n=65, 55%) and Barcelona Clinic Liver Cancer stage A (n=92, 77%) hepatocellular carcinoma. T+ samples displayed lower IT CD4+/FOXP3+ (p=0.006), CD8+ (p=0.002) and CD8+/PD-1+ and NT CD8+/PD-1+ (p<0.001) compared with T−. Lower IT (p=0.005) and NT CD4+/FOXP3+ (p=0.03) predicted for improved recurrence-free survival. In a subset of samples (n=24), transcriptomic analysis revealed upregulation of a pro-inflammatory response in T+. T+ samples were enriched for IRF2 expression (p=0.01), an interferon-regulated transcription factor implicated in cancer immune-evasion. T-cell clonality and expression of PD-L1, IDO-1, CTLA-4, Lag-3, Tim-3 and CD163 was similar in T+ versus T−. Conclusions TACE is associated with lower IT density of immune-exhausted effector cytotoxic and T-regs, with significant upregulation of pro-inflammatory pathways. This highlights the pleiotropic effects of TACE in modulating the tumor microenvironment and strengthens the rationale for developing immunotherapy alongside TACE.DJP is supported by grant funding from the Wellcome Trust Strategic Fund (PS3416) and by the Cancer Research UK Postdoctoral bursary (C57701/A26137). AF is supported by grant from Instituto de Salud Carlos III (PI18/00542)

Assessing the impact of COVID-19 on liver cancer management (CERO-19)

Coronavirus SARS-CoV-2; COVID-19; 2019-nCoV; Assaigs clínics; Càncer de fetgeCoronavirus SARS-CoV-2; COVID-19; 2019-nCoV; Ensayos clínicos; Cáncer de hígadoCoronavirus SARS-CoV-2; COVID-19; 2019-nCoV; Clinical trials; Liver cancerBackground & aims: The coronavirus disease 2019 (COVID-19) pandemic has posed unprecedented challenges to healthcare systems and it may have heavily impacted patients with liver cancer (LC). Herein, we evaluated whether the schedule of LC screening or procedures has been interrupted or delayed because of the COVID-19 pandemic. Methods: An international survey evaluated the impact of the COVID-19 pandemic on clinical practice and clinical trials from March 2020 to June 2020, as the first phase of a multicentre, international, and observational project. The focus was on patients with hepatocellular carcinoma or intrahepatic cholangiocarcinoma, cared for around the world during the first COVID-19 pandemic wave. Results: Ninety-one centres expressed interest to participate and 76 were included in the analysis, from Europe, South America, North America, Asia, and Africa (73.7%, 17.1%, 5.3%, 2.6%, and 1.3% per continent, respectively). Eighty-seven percent of the centres modified their clinical practice: 40.8% the diagnostic procedures, 80.9% the screening programme, 50% cancelled curative and/or palliative treatments for LC, and 41.7% modified the liver transplantation programme. Forty-five out of 69 (65.2%) centres in which clinical trials were running modified their treatments in that setting, but 58.1% were able to recruit new patients. The phone call service was modified in 51.4% of centres which had this service before the COVID-19 pandemic (n = 19/37). Conclusions: The first wave of the COVID-19 pandemic had a tremendous impact on the routine care of patients with liver cancer. Modifications in screening, diagnostic, and treatment algorithms may have significantly impaired the outcome of patients. Ongoing data collection and future analyses will report the benefits and disadvantages of the strategies implemented, aiding future decision-making. Lay summary: The coronavirus disease 2019 (COVID-19) pandemic has posed unprecedented challenges to healthcare systems globally. Herein, we assessed the impact of the first wave pandemic on patients with liver cancer and found that routine care for these patients has been majorly disrupted, which could have a significant impact on outcomes.There was no funding for this study

A conserved arginine with non-conserved function is a key determinant of agonist selectivity in α7 nicotinic ACh receptors

The α7 and α4β2* (“*” denotes possibly assembly with another subunit) nicotinic acetylcholine receptors (nAChRs) are the most abundant nAChRs in the mammalian brain. These receptors are the most targeted nAChRs in drug discovery programmes for brain disorders. However, the development of subtype-specific agonists remains challenging due to the high degree of sequence homology and conservation of function in nAChRs. We have developed C(10) variants of cytisine, a partial agonist of α4β2 nAChR that has been used for smoking cessation. The C(10) methyl analogue used in this study displays negligible affinity for α7 nAChR, while retaining high affinity for α4β2 nAChR.Fil: Minguez Viñas, Teresa. Oxford Brookes University; Reino UnidoFil: Nielsen, Beatriz Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; ArgentinaFil: Shoemark, Deborah K.. University Of Bristol; Reino UnidoFil: Gotti, Cecilia. Università degli Studi di Milano; ItaliaFil: Sessions, Richard B.. University Of Bristol; Reino UnidoFil: Mulholland, Adrian J.. University Of Bristol; Reino UnidoFil: Bouzat, Cecilia Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; ArgentinaFil: Wonnacott, Susan. University of Bath; Reino UnidoFil: Gallagher, Timothy. University Of Bristol; Reino UnidoFil: Bermudez, Isabel. University of Oxford; Reino UnidoFil: Oliveira, Ana Sofia. University Of Bristol; Reino Unid

A conserved arginine with non-conserved function is a key determinant of agonist selectivity in α7 nicotinic ACh receptors

Background and Purpose: The α7 and α4β2* (“*” denotes possibly assembly with another subunit) nicotinic acetylcholine receptors (nAChRs) are the most abundant nAChRs in the mammalian brain. These receptors are the most targeted nAChRs in drug discovery programmes for brain disorders. However, the development of subtype-specific agonists remains challenging due to the high degree of sequence homology and conservation of function in nAChRs. We have developed C(10) variants of cytisine, a partial agonist of α4β2 nAChR that has been used for smoking cessation. The C(10) methyl analogue used in this study displays negligible affinity for α7 nAChR, while retaining high affinity for α4β2 nAChR. Experimental Approach: The structural underpinning of the selectivity of 10-methylcytisine for α7 and α4β2 nAChRs was investigated using molecular dynamic simulations, mutagenesis and whole-cell and single-channel current recordings. Key Results: We identified a conserved arginine in the β3 strand that exhibits a non-conserved function in nAChRs. In α4β2 nAChR, the arginine forms a salt bridge with an aspartate residue in loop B that is necessary for receptor expression, whereas in α7 nAChR, this residue is not stabilised by electrostatic interactions, making its side chain highly mobile. This lack of constrain produces steric clashes with agonists and affects the dynamics of residues involved in agonist binding and the coupling network. Conclusion and Implications: We conclude that the high mobility of the β3-strand arginine in the α7 nAChR influences agonist binding and possibly gating network and desensitisation. The findings have implications for rational design of subtype-selective nAChR agents.</p

Loss of glutathione redox homeostasis impairs proteostasis by inhibiting autophagy-dependent protein degradation

In the presence of aggregation-prone proteins, the cytosol and endoplasmic reticulum (ER) undergo a dramatic shift in their respective redox status, with the cytosol becoming more oxidized and the ER more reducing. However, whether and how changes in the cellular redox status may affect protein aggregation is unknown. Here, we show that C. elegans loss-of-function mutants for the glutathione reductase gsr-1 gene enhance the deleterious phenotypes of heterologous human, as well as endogenous worm aggregation-prone proteins. These effects are phenocopied by the GSH-depleting agent diethyl maleate. Additionally, gsr-1 mutants abolish the nuclear translocation of HLH-30/TFEB transcription factor, a key inducer of autophagy, and strongly impair the degradation of the autophagy substrate p62/SQST-1::GFP, revealing glutathione reductase may have a role in the clearance of protein aggregates by autophagy. Blocking autophagy in gsr-1 worms expressing aggregation-prone proteins results in strong synthetic developmental phenotypes and lethality, supporting the physiological importance of glutathione reductase in the regulation of misfolded protein clearance. Furthermore, impairing redox homeostasis in both yeast and mammalian cells induces toxicity phenotypes associated with protein aggregation. Together, our data reveal that glutathione redox homeostasis may be central to proteostasis maintenance through autophagy regulation.Ministerio de Economía y Competitividad BFU2016–78265-P, BFU2016– 79313-P, MDM-2016–0687, BFU2015–64408-PInstituto de Salud Carlos III PI11/ 00072, CPII16/00004, PI14/00949, PI17/0001

Exploring plasma coenzyme Q10 status in paediatric dyslipidaemia

Coenzyme Q10 (CoQ) is a ubiquitous lipid with different biological functions. In blood, there is a close relationship between CoQ status and cholesterol, which strongly supports the study of both molecules simultaneously. The objective of this study was to evaluate plasma CoQ, lipoprotein concentrations and CoQ/Chol ratio in a cohort of paediatric patients with different types of dyslipidaemias. A total of 60 paediatric patients were recruited (age range: 7 months–18 years), including 52 with different types of hypercholesterolemia, 2 with isolated hypertriglyceridemia and 6 with hypobetalipoproteinemia. Plasma CoQ was analysed by HPLC with electrochemical detection, and lipoprotein and cholesterol concentrations by standard automated methods. The lowest CoQ values were detected in patients with hypobetalipoproteinemia and in two cases of liver cirrhosis. Mean CoQ values were significantly higher in hypercholesterolemic patients compared to controls (average values 1.07 µmol/L and 0.63 µmol/L) while the CoQ/cholesterol ratio did not show differences (170 vs. 163, respectively). Mean CoQ values were significantly lower in the group of patients with hypobetalipoproteinemia compared to controls (mean CoQ values of 0.22 µmol/L vs. 0.63 µmol/L, respectively), while those of CoQ/cholesterol did not show differences. Pearson’s correlation test showed a positive correlation between the CoQ and cholesterol values (r = 0.565, p < 0.001) and between the CoQ and the LDL cholesterol values (r = 0.610, p < 0.001). Our results suggest that it is advisable to analyse plasma CoQ and cholesterol concentrations in patients with hypobetalipoproteinemia and hypercholesterolemia associated with liver damage.Peer ReviewedPostprint (published version