Fibroblast-Derived Lysyl Oxidase Increases Oxidative Phosphorylation and Stemness in Cholangiocarcinoma.

BACKGROUND & AIMS: Metabolic and transcriptional programs respond to extracellular matrix-derived cues in complex environments, such as the tumor microenvironment. Here, we demonstrate how lysyl oxidase (LOX), a known factor in collagen crosslinking, contributes to the development and progression of cholangiocarcinoma (CCA). METHODS: Transcriptomes of 209 human CCA tumors, 143 surrounding tissues, and single-cell data from 30 patients were analyzed. The recombinant protein and a small molecule inhibitor of the LOX activity were used on primary patient-derived CCA cultures to establish the role of LOX in migration, proliferation, colony formation, metabolic fitness, and the LOX interactome. The oncogenic role of LOX was further investigated by RNAscope and in vivo using the AKT/NICD genetically engineered murine CCA model. RESULTS: We traced LOX expression to hepatic stellate cells and specifically hepatic stellate cell-derived inflammatory cancer-associated fibroblasts and found that cancer-associated fibroblast-driven LOX increases oxidative phosphorylation and metabolic fitness of CCA, and regulates mitochondrial function through transcription factor A, mitochondrial. Inhibiting LOX activity in vivo impedes CCA development and progression. Our work highlights that LOX alters tumor microenvironment-directed transcriptional reprogramming of CCA cells by facilitating the expression of the oxidative phosphorylation pathway and by increasing stemness and mobility. CONCLUSIONS: Increased LOX is driven by stromal inflammatory cancer-associated fibroblasts and correlates with diminished survival of patients with CCA. Modulating the LOX activity can serve as a novel tumor microenvironment-directed therapeutic strategy in bile duct pathologies.

PARP-1 selectively impairs KRAS-driven phenotypic and molecular features in intrahepatic cholangiocarcinoma.

OBJECTIVE: Intrahepatic cholangiocarcinoma (iCCA) is the second most common primary liver cancer with limited therapeutic options. KRAS mutations are among the most abundant genetic alterations in iCCA associated with poor clinical outcome and treatment response. Recent findings indicate that Poly(ADP-ribose)polymerase1 (PARP-1) is implicated in KRAS-driven cancers, but its exact role in cholangiocarcinogenesis remains undefined. DESIGN: PARP-1 inhibition was performed in patient-derived and established iCCA cells using RNAi, CRISPR/Cas9 and pharmacological inhibition in KRAS-mutant, non-mutant cells. In addition, Parp-1 knockout mice were combined with iCCA induction by hydrodynamic tail vein injection to evaluate an impact on phenotypic and molecular features of Kras-driven and Kras-wildtype iCCA. Clinical implications were confirmed in authentic human iCCA. RESULTS: PARP-1 was significantly enhanced in KRAS-mutant human iCCA. PARP-1-based interventions preferentially impaired cell viability and tumourigenicity in human KRAS-mutant cell lines. Consistently, loss of Parp-1 provoked distinct phenotype in Kras/Tp53-induced versus Akt/Nicd-induced iCCA and abolished Kras-dependent cholangiocarcinogenesis. Transcriptome analyses confirmed preferential impairment of DNA damage response pathways and replicative stress response mediated by CHK1. Consistently, inhibition of CHK1 effectively reversed PARP-1 mediated effects. Finally, Parp-1 depletion induced molecular switch of KRAS-mutant iCCA recapitulating good prognostic human iCCA patients. CONCLUSION: Our findings identify the novel prognostic and therapeutic role of PARP-1 in iCCA patients with activation of oncogenic KRAS signalling.

Lower uromodulin serum levels are associated with poorer prognosis in patients with cirrhosis and hepatorenal syndrome type 2.

Hepatorenal syndrome (HRS) is associated with a dismal prognosis in patients with cirrhosis, and therapeutic options are limited. Biomarkers to identify patients with poor response to therapy are urgently needed. This study aimed to evaluate the predictive value of serum levels of uromodulin (sUMOD) in patients with cirrhosis and HRS treated with terlipressin and albumin (T/A). In total, 156 patients [81 patients with HRS treated with T/A, 42 patients with cirrhosis without kidney injury, and 33 patients with cirrhosis with prerenal acute kidney injury (AKI)] were included. sUMOD levels were analyzed by ELISA. Patients with HRS were prospectively followed for the composite endpoint of hemodialysis-/liver transplantation-free survival (HD/LTx-free survival). Of the 81 patients with HRS, 40 had HRS type 1 and 41 type 2. In the cohort of patients with HRS treated with T/A, median sUMOD level was 100 ng/mL (IQR 64; 144). sUMOD differed significantly between patients with HRS compared with patients without AKI (P = 0.001) but not between patients with HRS and prerenal AKI (P = 0.9). In multivariable analyses, sUMOD levels in the lowest quartile were independently associated with a lower rate of complete response to T/A (OR 0.042, P = 0.008) and a higher risk for reaching the composite endpoint of HD/LTX-free survival (HR 2.706, P = 0.013) in patients with HRS type 2 treated with T/A. In contrast, sUMOD was not significantly associated with these outcomes in patients with HRS type 1. sUMOD may be a valuable biomarker for identifying patients with HRS type 2 treated with T/A to predict response and prognosis.NEW & NOTEWORTHY Biomarkers identifying patients with hepatorenal syndrome (HRS) and poor response to therapy are urgently needed. In this study, lower serum uromodulin (sUMOD) levels were associated with poorer response to therapy with terlipressin and albumin and consequently with poorer prognosis in patients with HRS type 2. In patients with HRS type 1, there was no association between sUMOD and poorer prognosis.

Molecular Markers of Response to Anti-PD1 Therapy in Advanced Hepatocellular Carcinoma.

BACKGROUND & AIMS: Single-agent anti-PD1 checkpoint inhibitors convey outstanding clinical benefits in a small fraction (∼20%) of patients with advanced hepatocellular carcinoma (aHCC) but the molecular mechanisms determining response are unknown. To fill this gap, we herein analyze the molecular and immune traits of aHCC in patients treated with anti-PD1. METHODS: Overall, 111 tumor samples from patients with aHCC were obtained from 13 centers before systemic therapies. We performed molecular analysis and immune deconvolution using whole-genome expression data (n = 83), mutational analysis (n = 72), and histologic evaluation with an endpoint of objective response. RESULTS: Among 83 patients with transcriptomic data, 28 were treated in frontline, whereas 55 patients were treated after tyrosine kinase inhibitors (TKI) either in second or third line. Responders treated in frontline showed upregulated interferon-γ signaling and major histocompatibility complex II-related antigen presentation. We generated an 11-gene signature (IFNAP), capturing these molecular features, which predicts response and survival in patients treated with anti-PD1 in frontline. The signature was validated in a separate cohort of aHCC and >240 patients with other solid cancer types where it also predicted response and survival. Of note, the same signature was unable to predict response in archival tissue of patients treated with frontline TKIs, highlighting the need for fresh biopsies before immunotherapy. CONCLUSION: Interferon signaling and major histocompatibility complex-related genes are key molecular features of HCCs responding to anti-PD1. A novel 11-gene signature predicts response in frontline aHCC, but not in patients pretreated with TKIs. These results must be confirmed in prospective studies and highlights the need for biopsies before immunotherapy to identify biomarkers of response.

Minimal hepatic encephalopathy is associated with a higher risk of overt hepatic encephalopathy and poorer survival.

BACKGROUND AND AIMS: Minimal hepatic encephalopathy (MHE) is a frequent complication in patients with liver cirrhosis. Its impact on predicting the development of overt hepatic encephalopathy (OHE) and survival has not been studied in large multicenter studies. METHODS: Data from patients recruited at eight centers across Europe and the United States were analyzed. MHE was detected using the psychometric hepatic encephalopathy score (PHES). A subset was also tested with the simplified animal naming test (S-ANT1). Patients were followed for OHE development and death/liver transplantation (LTx). RESULTS: A total of 1462 patients with a median model of end-stage liver disease of 11 were included (Child-Pugh (CP) stages: A 47%/B 41%/C 12%). Median follow-up time was 19 months, during which 336 (23%) patients developed an OHE episode and 464 (32%) reached the composite end point of death/LTx (369 deaths, 95 LTx). In multivariable analyses, MHE (defined by PHES) was associated with the development of OHE (subdistribution hazard ratio 1.74, p < 0.001) and poorer LTx-free survival (hazard ratio 1.53, p < 0.001) in the total cohort as well as in the subgroup of patients without a history of OHE. In subgroup analyses, MHE (defined by PHES) was associated with OHE development in patients with CP B, whereas there was no association in patients with CP A or C. In the subgroup of patients with available S-ANT1, MHE (defined by S-ANT1) was independently associated with OHE development. Combined testing (PHES+S-ANT1) was superior to single testing for predicting OHE and poorer LTx-free survival. CONCLUSIONS: This large multicenter study demonstrates that screening for MHE is a useful tool for predicting OHE and poorer survival.

Genetic variation in TERT modifies the risk of hepatocellular carcinoma in alcohol-related cirrhosis: results from a genome-wide case-control study.

OBJECTIVE: Hepatocellular carcinoma (HCC) often develops in patients with alcohol-related cirrhosis at an annual risk of up to 2.5%. Some host genetic risk factors have been identified but do not account for the majority of the variance in occurrence. This study aimed to identify novel susceptibility loci for the development of HCC in people with alcohol related cirrhosis. DESIGN: Patients with alcohol-related cirrhosis and HCC (cases: n=1214) and controls without HCC (n=1866), recruited from Germany, Austria, Switzerland, Italy and the UK, were included in a two-stage genome-wide association study using a case-control design. A validation cohort of 1520 people misusing alcohol but with no evidence of liver disease was included to control for possible association effects with alcohol misuse. Genotyping was performed using the InfiniumGlobal Screening Array (V.24v2, Illumina) and the OmniExpress Array (V.24v1-0a, Illumina). RESULTS: Associations with variants rs738409 in PNPLA3 and rs58542926 in TM6SF2 previously associated with an increased risk of HCC in patients with alcohol-related cirrhosis were confirmed at genome-wide significance. A novel locus rs2242652(A) in TERT (telomerase reverse transcriptase) was also associated with a decreased risk of HCC, in the combined meta-analysis, at genome-wide significance (p=6.41×10-9, OR=0.61 (95% CI 0.52 to 0.70). This protective association remained significant after correction for sex, age, body mass index and type 2 diabetes (p=7.94×10-5, OR=0.63 (95% CI 0.50 to 0.79). Carriage of rs2242652(A) in TERT was associated with an increased leucocyte telomere length (p=2.12×10-44). CONCLUSION: This study identifies rs2242652 in TERT as a novel protective factor for HCC in patients with alcohol-related cirrhosis.

Secondary Sclerosing Cholangitis Following Coronavirus Disease 2019 (COVID-19): A Multicenter Retrospective Study.

BACKGROUND: Secondary sclerosing cholangitis (SSC) is a rare disease with poor prognosis. Cases of SSC have been reported following coronavirus disease 2019 (COVID-SSC). The aim of this study was to compare COVID-SSC to SSC in critically ill patients (SSC-CIP) and to assess factors influencing transplant-free survival. METHODS: In this retrospective, multicenter study involving 127 patients with SSC from 9 tertiary care centers in Germany, COVID-SSC was compared to SSC-CIP and logistic regression analyses were performed investigating factors impacting transplant-free survival. RESULTS: Twenty-four patients had COVID-SSC, 77 patients SSC-CIP, and 26 patients other forms of SSC. COVID-SSC developed after a median of 91 days following COVID-19 diagnosis. All patients had received extensive intensive care treatment (median days of mechanical ventilation, 48). Patients with COVID-SSC and SSC-CIP were comparable in most of the clinical parameters and transplant-free survival was not different from other forms of SSC (P = .443, log-rank test). In the overall cohort, the use of ursodeoxycholic acid (UDCA) (odds ratio [OR], 0.36 [95% confidence interval {CI}, .16-.80], P = .013; log-rank P < .001) and high serum albumin levels (OR, 0.40 [95% CI, .17-.96], P = .040) were independently associated with an increased transplant-free survival, while the presence of liver cirrhosis (OR, 2.52 [95% CI, 1.01-6.25], P = .047) was associated with worse outcome. Multidrug-resistant organism (MDRO) colonization or infection did not impact patients' survival. CONCLUSIONS: COVID-SSC and CIP-SSC share the same clinical phenotype, course of the disease, and risk factors for its development. UDCA may be a promising therapeutic option in SSC, though future prospective trials are needed to confirm our findings.

MicroRNA-27a-3p targets FoxO signalling to induce tumour-like phenotypes in bile duct cells.

BACKGROUND & AIMS: Cholangiocarcinoma (CCA) is a heterogeneous and lethal malignancy, the molecular origins of which remain poorly understood. MicroRNAs (miRs) target diverse signalling pathways, functioning as potent epigenetic regulators of transcriptional output. We aimed to characterise miRNome dysregulation in CCA, including its impact on transcriptome homeostasis and cell behaviour. METHODS: Small RNA sequencing was performed on 119 resected CCAs, 63 surrounding liver tissues, and 22 normal livers. High-throughput miR mimic screens were performed in three primary human cholangiocyte cultures. Integration of patient transcriptomes and miRseq together with miR screening data identified an oncogenic miR for characterization. MiR-mRNA interactions were investigated by a luciferase assay. MiR-CRISPR knockout cells were generated and phenotypically characterized in vitro (proliferation, migration, colony, mitochondrial function, glycolysis) and in vivo using subcutaneous xenografts. RESULTS: In total, 13% (140/1,049) of detected miRs were differentially expressed between CCA and surrounding liver tissues, including 135 that were upregulated in tumours. CCA tissues were characterised by higher miRNome heterogeneity and miR biogenesis pathway expression. Unsupervised hierarchical clustering of tumour miRNomes identified three subgroups, including distal CCA-enriched and IDH1 mutant-enriched subgroups. High-throughput screening of miR mimics uncovered 71 miRs that consistently increased proliferation of three primary cholangiocyte models and were upregulated in CCA tissues regardless of anatomical location, among which only miR-27a-3p had consistently increased expression and activity in several cohorts. FoxO signalling was predominantly downregulated by miR-27a-3p in CCA, partially through targeting of FOXO1. MiR-27a knockout increased FOXO1 levels in vitro and in vivo, impeding tumour behaviour and growth. CONCLUSIONS: The miRNomes of CCA tissues are highly remodelled, impacting transcriptome homeostasis in part through regulation of transcription factors like FOXO1. MiR-27a-3p arises as an oncogenic vulnerability in CCA. IMPACT AND IMPLICATIONS: Cholangiocarcinogenesis entails extensive cellular reprogramming driven by genetic and non-genetic alterations, but the functional roles of these non-genetic events remain poorly understood. By unveiling global miRNA upregulation in patient tumours and their functional ability to increase proliferation of cholangiocytes, these small non-coding RNAs are implicated as critical non-genetic alterations promoting biliary tumour initiation. These findings identify possible mechanisms for transcriptome rewiring during transformation, with potential implications for patient stratification.

Prevalence of Minimal Hepatic Encephalopathy in Patients With Liver Cirrhosis: A Multicenter Study.

INTRODUCTION: The prevalence of minimal hepatic encephalopathy (MHE), in particular in different subgroups, remains unknown. This study aimed to analyze the prevalence of MHE in different subgroups to identify patients at high risk and to pave the way for personalized screening approaches. METHODS: In this study, data of patients recruited at 10 centers across Europe and the United States were analyzed. Only patients without clinical signs of hepatic encephalopathy were included. MHE was detected using the Psychometric Hepatic Encephalopathy Score (PHES, cut-off < or ≤-4 depending on local norms). Clinical and demographic characteristics of the patients were assessed and analyzed. RESULTS: In total, 1,868 patients with cirrhosis with a median model for end-stage liver disease (MELD) of 11 were analyzed (Child-Pugh [CP] stages: A 46%, B 42%, and C 12%). In the total cohort, MHE was detected by PHES in 650 patients (35%). After excluding patients with a history of overt hepatic encephalopathy, the prevalence of MHE was 29%. In subgroup analyses, the prevalence of MHE in patients with CP A was low (25%), whereas it was high in CP B or C (42% and 52%). In patients with a MELD score <10, the prevalence of MHE was only 25%, but it was 48% in patients with a MELD score ≥20. Standardized ammonia levels (ammonia level/upper limit of normal of each center) correlated significantly, albeit weakly with PHES (Spearman ρ = -0.16, P < 0.001). DISCUSSION: The prevalence of MHE in patients with cirrhosis was high but varied substantially between diseases stages. These data may pave the way for more individualized MHE screening approaches.

Prospective study of computer-aided detection of colorectal adenomas in hospitalized patients.

BACKGROUND: Adenoma detection with polypectomy during total colonoscopy reduces the incidence of colorectal cancer (CRC) and colorectal cancer-associated mortality. The adenoma detection rate (ADR) is an established quality indicator, which is associated with a decreased risk for interval cancer. An increase in ADR could be demonstrated for several artificially intelligent, real-time computer-aided detection (CADe) systems in selected patients. Most studies concentrated on outpatient colonoscopies. This sector often lacks funds for applying costly innovations like CADe. Hospitals are more likely to implement CADe and information about the impact of CADe in the distinct patient cohort of hospitalized patients is scarce. METHODS: In this prospective, randomized-controlled study, we compared colonoscopies performed with or without computer-aided detection (CADe) system (GI Genius, Medtronic) performed at University Medical Center Schleswig-Holstein, Campus Luebeck. The primary endpoint was ADR. RESULTS: Overall, 232 patients were randomized with n = 122 patients in the CADe arm and n = 110 patients in the control arm. Median age was 66 years (interquartile range 51-77). Indication for colonoscopy was most often workup for gastrointestinal symptoms (88.4%) followed by screening, post-polypectomy and post-CRC surveillance (each 3.9%). Withdrawal time was significantly prolonged (11 vs. 10 min, p = 0.039), without clinical relevance. Complication rate was not different between the arms (0.8% vs. 4.5%; p = 0.072). The ADR was significantly increased in the CADe arm compared to the control (33.6% vs. 18.1%, p = 0.008). ADR increase was particularly strong for the detection in elderly patients aged ≥50 years (OR 6.3, 95% CI 1.7 - 23.1, p = 0.006). CONCLUSION: The use of CADe is safe and increases ADR in hospitalized patients.

Evaluation of the Diagnostic Value of Oesophageal Biopsies for Direct Immunofluorescence Microscopy in Mucous Membrane Pemphigoid.

Mucous membrane pemphigoid is an autoimmune blistering disorder characterized by predominant involvement of surface-close epithelia and linear depositions of immunoreactants at the dermal-epithelial junction on direct immunofluorescence microscopy. A major diagnostic difficulty is the frequent need for multiple biopsies to facilitate the diagnosis. Although oesophageal involvement is a rare, but life-threatening manifestation, the relevance of oesophageal direct immunofluorescence sampling is unclear. This retrospective monocentric study evaluated 67 non-lesional biopsies from 11 patients with mucous membrane pemphigoid and clinical symptoms suggestive of oesophageal involvement, comprising 31 samples from the oesophagus and 36 samples from other anatomical sites. Five patients (45.5%) exhibited endoscopic findings compatible with oesophageal involvement of mucous membrane pemphigoid. No correlation was identified between the presence of oesophageal lesions and direct immunofluorescence positivity in lesions from the oesophagus (p = 1.0). Oral and cutaneous samples were significantly more frequently positive by direct immunofluorescence than were oesophageal biopsies (p < 0.0001 and p = 0.0195, respectively). Oesophageal samples yielded significantly less IgG reactivity than oral and cutaneous lesions (p < 0.0001 and p = 0.0126, respectively), and less IgA antibody response than oral lesions (p = 0.0036). In conclusion, oesophageal direct immunofluorescence samples were inferior to oral and cutaneous biopsies for the diagnosis of mucous membrane pemphigoid even when oesophageal lesions compatible with mucous membrane pemphigoid were present at the time of biopsy.

Determination of primary microRNA processing in clinical samples by targeted pri-miR-sequencing.

MicroRNA expression is important for gene regulation and deregulated microRNA expression is often observed in diseases such as cancer. The processing of primary microRNA transcripts is an important regulatory step in microRNA biogenesis. Due to low expression level and association with chromatin, primary microRNAs are challenging to study in clinical samples where input material is limited. Here, we present a high-sensitivity targeted method to determine processing efficiency of several hundred primary microRNAs from total RNA that requires relatively few RNA sequencing reads. We validate the method using RNA from HeLa cells and show the applicability to clinical samples by analyzing RNA from normal liver and hepatocellular carcinoma. We identify 24 primary microRNAs with significant changes in processing efficiency from normal liver to hepatocellular carcinoma, among those the highly expressed miRNA-122 and miRNA-21, demonstrating that differential processing of primary microRNAs is occurring and could be involved in disease. With our method presented here we provide means to study pri-miRNA processing in disease from clinical samples.

The Co-mutational Spectrum Determines the Therapeutic Response in Murine FGFR2 Fusion-Driven Cholangiocarcinoma.

BACKGROUND AND AIMS: Intrahepatic cholangiocarcinoma (ICC) is the second most common primary liver cancer and a highly lethal malignancy. Chemotherapeutic options are limited, but a considerable subset of patients harbors genetic lesions for which targeted agents exist. Fibroblast growth factor receptor 2 (FGFR2) fusions belong to the most frequent and therapeutically relevant alterations in ICC, and the first FGFR inhibitor was recently approved for the treatment of patients with progressed, fusion-positive ICC. Response rates of up to 35% indicate that FGFR-targeted therapies are beneficial in many but not all patients. Thus far, no established biomarkers exist that predict resistance or response to FGFR-targeted therapies in patients with ICC. APPROACH AND RESULTS: In this study, we use an autochthonous murine model of ICC to demonstrate that FGFR2 fusions are potent drivers of malignant transformation. Furthermore, we provide preclinical evidence that the co-mutational spectrum acts not only as an accelerator of tumor development, but also modifies the response to targeted FGFR inhibitors. Using pharmacologic approaches and RNA-interference technology, we delineate that Kirsten rat sarcoma oncogene (KRAS)-activated mitogen-activated protein kinase signaling causes primary resistance to FGFR inhibitors in FGFR2 fusion-positive ICC. The translational relevance is supported by the observation that a subset of human FGFR2 fusion patients exhibits transcriptome profiles reminiscent of KRAS mutant ICC. Moreover, we demonstrate that combination therapy has the potential to overcome primary resistance and to sensitize tumors to FGFR inhibition. CONCLUSIONS: Our work highlights the importance of the co-mutational spectrum as a significant modifier of response in tumors that harbor potent oncogenic drivers. A better understanding of the genetic underpinnings of resistance will be pivotal to improve biomarker-guided patient selection and to design clinically relevant combination strategies.

Continued alcohol consumption and hepatic encephalopathy determine quality of life and psychosocial burden of caregivers in patients with liver cirrhosis.

BACKGROUND: Patients with liver cirrhosis suffer from significantly reduced health-related quality of life and are often dependent on support from caregivers. In this context, caregivers often suffer from impaired quality of life (QoL) as well as psychosocial burden (PB). The aim of the present study was to identify factors influencing QoL and PB of caregivers in order to improve the social care of patients and caregivers. METHODS: In this cross-sectional study, 106 patients with liver cirrhosis and their caregivers were included. (Health-related) QoL was surveyed in patients (CLDQ) and caregivers (SF-36) and PB was determined by Zarit Burden Interview. RESULTS: Alcohol related liver cirrhosis (55%) was the predominant etiology of liver cirrhosis and the median MELD of the cohort was 14. QoL did not differ between patients with and without alcohol-related liver cirrhosis (p = 0.6). In multivariable analysis, continued alcohol consumption (p = 0.020), a history of hepatic encephalopathy (HE) (p = 0.010), poorer QoL of patients (p = 0.030) and poorer QoL of caregivers (p = 0.005) were associated with a higher PB of caregivers. Factors independently associated with poorer QoL of caregivers were continued alcohol consumption (p = 0.003) and a higher PB of caregivers (p = 0.030). CONCLUSION: Caregivers of patients with liver cirrhosis suffer from impaired QoL and PB, especially in case of continued alcohol consumption or the occurrence of HE.

CD44 Contributes to the Regulation of MDR1 Protein and Doxorubicin Chemoresistance in Osteosarcoma.

Osteosarcoma is the most common type of pediatric bone tumor. Despite great advances in chemotherapy during the past decades, the survival rates of osteosarcoma patients remain unsatisfactory. Drug resistance is one of the main reasons, leading to treatment failure and poor prognosis. Previous reports correlated expression of cluster of differentiation 44 (CD44) with drug resistance and poor survival of osteosarcoma patients, however the underlying mechanisms are poorly defined. Here, we investigated the role of CD44 in the regulation of drug chemoresistance, using osteosarcoma cells isolated from mice carrying a mutation of the tumor suppressor neurofibromatosis type 2 (Nf2) gene. CD44 expression was knocked-down in the cells using CRISPR/Cas9 approach. Subsequently, CD44 isoforms and mutants were re-introduced to investigate CD44-dependent processes. Sensitivity to doxorubicin was analyzed in the osteosarcoma cells with modified CD44 expression by immunoblot, colony formation- and WST-1 assay. To dissect the molecular alterations induced by deletion of Cd44, RNA sequencing was performed on Cd44-positive and Cd44-negative primary osteosarcoma tissues isolated from Nf2-mutant mice. Subsequently, expression of candidate genes was evaluated by quantitative reverse transcription PCR (qRT-PCR). Our results indicate that CD44 increases the resistance of osteosarcoma cells to doxorubicin by up-regulating the levels of multidrug resistance (MDR) 1 protein expression, and suggest the role of proteolytically released CD44 intracellular domain, and hyaluronan interactions in this process. Moreover, high throughput sequencing analysis identified differential regulation of several apoptosis-related genes in Cd44-positive and -negative primary osteosarcomas, including p53 apoptosis effector related to PMP-22 (Perp). Deletion of Cd44 in osteosarcoma cells led to doxorubicin-dependent p53 activation and a profound increase in Perp mRNA expression. Overall, our results suggest that CD44 might be an important regulator of drug resistance and suggest that targeting CD44 can sensitize osteosarcoma to standard chemotherapy.

Differential Effects of Somatostatin, Octreotide, and Lanreotide on Neuroendocrine Differentiation and Proliferation in Established and Primary NET Cell Lines: Possible Crosstalk with TGF-ß Signaling.

GEP-NETs are heterogeneous tumors originating from the pancreas (panNET) or the intestinal tract. Only a few patients with NETs are amenable to curative tumor resection, and for most patients, only palliative treatments to successfully control the disease or manage symptoms remain, such as with synthetic somatostatin (SST) analogs (SSAs), such as octreotide (OCT) or lanreotide (LAN). However, even cells expressing low levels of SST receptors (SSTRs) may exhibit significant responses to OCT, which suggests the possibility that SSAs signal through alternative mechanisms, e.g., transforming growth factor (TGF)-ß. This signaling mode has been demonstrated in the established panNET line BON but not yet in other permanent (i.e., QGP) or primary (i.e., NT-3) panNET-derived cells. Here, we performed qPCR, immunoblot analyses, and cell counting assays to assess the effects of SST, OCT, LAN, and TGF-ß1 on neuroendocrine marker expression and cell proliferation in NT-3, QGP, and BON cells. SST and SSAs were found to regulate a set of neuroendocrine genes in all three cell lines, with the effects of SST, mainly LAN, often differing from those of OCT. However, unlike NT-3 cells, BON cells failed to respond to OCT with growth arrest but paradoxically exhibited a growth-stimulatory effect after treatment with LAN. As previously shown for BON, NT-3 cells responded to TGF-ß1 treatment with induction of expression of SST and SSTR2/5. Of note, the ability of NT-3 cells to respond to TGF-ß1 with upregulation of the established TGF-ß target gene SERPINE1 depended on cellular adherence to a collagen-coated matrix. Moreover, when applied to NT-3 cells for an extended period, i.e., 14 days, TGF-ß1 induced growth suppression as shown earlier for BON cells. Finally, next-generation sequencing-based identification of microRNAs (miRNAs) in BON and NT-3 revealed that SST and OCT impact positively or negatively on the regulation of specific miRNAs. Our results suggest that primary panNET cells, such as NT-3, respond similarly as BON cells to SST, SSA, and TGF-ß treatment and thus provide circumstantial evidence that crosstalk of SST and TGF-ß signaling is not confined to BON cells but is a general feature of panNETs.

[Current Studies and Evidence in Cholangiocarcinoma]. / Aktuelle Studien und Evidenz zum Cholangiokarzinom.

Cholangiocarcinoma (CCA) is the second most common type of primary liver cancer and includes a group of intra- and extrahepatic bile tract cancers. Prognosis of patients with CCA remains poor due to high recurrence rates after curative resections and often late diagnosis in advanced stages of the disease. Curative therapy is a complete resection that requires complex surgical procedures and potentially pre-operative induction of liver hypertrophy to ensure sufficient postoperative liver function. Adjuvant therapy with capecitabine for 6 months is well established in clinical routine. The therapeutic landscape for advanced stages is constantly progressing, due to new results of clinical phase II/III trials. On the one hand, molecular analyses have paved the way to effective targeted therapies for subgroups of CCA patients with alterations in FGFR2- or IDH1-signaling. On the other hand, immune-oncological approaches in combination with chemotherapy have resulted in safe and effective treatments for unselected patient cohorts. Further studies will investigate molecular-driven as well as immune-combination treatments in earlier stages of the disease and will result in new therapy options and better prognosis for CCA patients in the near future.

GDF11 restricts aberrant lipogenesis and changes in mitochondrial structure and function in human hepatocellular carcinoma cells.

Growth differentiation factor 11 (GDF11) has been characterized as a key regulator of differentiation in cells that retain stemness features. Recently, it has been reported that GDF11 exerts tumor-suppressive properties in hepatocellular carcinoma cells, decreasing clonogenicity, proliferation, spheroid formation, and cellular function, all associated with a decrement in stemness features, resulting in mesenchymal to epithelial transition and loss of aggressiveness. The aim of the present work was to investigate the mechanism associated with the tumor-suppressive properties displayed by GDF11 in liver cancer cells. Hepatocellular carcinoma-derived cell lines were exposed to GDF11 (50 ng/ml), RNA-seq analysis in Huh7 cell line revealed that GDF11 exerted profound transcriptomic impact, which involved regulation of cholesterol metabolic process, steroid metabolic process as well as key signaling pathways, resembling endoplasmic reticulum-related functions. Cholesterol and triglycerides determination in Huh7 and Hep3B cells treated with GDF11 exhibited a significant decrement in the content of these lipids. The mTOR signaling pathway was downregulated, and this was associated with a reduction in key proteins involved in the mevalonate pathway. In addition, real-time metabolism assessed by Seahorse technology showed abridged glycolysis as well as glycolytic capacity, closely related to an impaired oxygen consumption rate and decrement in adenosine triphosphate production. Finally, transmission electron microscopy revealed mitochondrial abnormalities, such as cristae disarrangement, consistent with metabolic changes. Results provide evidence that GDF11 impairs cancer cell metabolism targeting lipid homeostasis, glycolysis, and mitochondria function and morphology.

Genetic Variation in HSD17B13 Reduces the Risk of Developing Cirrhosis and Hepatocellular Carcinoma in Alcohol Misusers.

BACKGROUND AND AIMS: Carriage of rs738409:G in patatin-like phospholipase domain containing 3 (PNPLA3) is associated with an increased risk for developing alcohol-related cirrhosis and hepatocellular carcinoma (HCC). Recently, rs72613567:TA in hydroxysteroid 17-beta dehydrogenase 13 (HSD17B13) was shown to be associated with a reduced risk for developing alcohol-related liver disease and to attenuate the risk associated with carriage of PNPLA3 rs738409:G. This study explores the risk associations between these two genetic variants and the development of alcohol-related cirrhosis and HCC. APPROACH AND RESULTS: Variants in HSD17B13 and PNPLA3 were genotyped in 6,171 participants, including 1,031 with alcohol-related cirrhosis and HCC, 1,653 with alcohol-related cirrhosis without HCC, 2,588 alcohol misusers with no liver disease, and 899 healthy controls. Genetic associations with the risks for developing alcohol-related cirrhosis and HCC were determined using logistic regression analysis. Carriage of HSD17B13 rs72613567:TA was associated with a lower risk for developing both cirrhosis (odds ratio [OR], 0.79; 95% confidence interval [CI], 0.72-0.88; P = 8.13 × 10-6 ) and HCC (OR, 0.77; 95% CI, 0.68-0.89; P = 2.27 × 10-4 ), whereas carriage of PNPLA3 rs738409:G was associated with an increased risk for developing cirrhosis (OR, 1.70; 95% CI, 1.54-1.88; P = 1.52 × 10-26 ) and HCC (OR, 1.77; 95% CI, 1.58-1.98; P = 2.31 × 10-23 ). These associations remained significant after adjusting for age, sex, body mass index, type 2 diabetes, and country. Carriage of HSD17B13 rs72613567:TA attenuated the risk for developing cirrhosis associated with PNPLA3 rs738409:G in both men and women, but the protective effect against the subsequent development of HCC was only observed in men (ORallelic , 0.75; 95% CI, 0.64-0.87; P = 1.72 × 10-4 ). CONCLUSIONS: Carriage of variants in PNPLA3 and HSD17B13 differentially affect the risk for developing advanced alcohol-related liver disease. A genotypic/phenotypic risk score might facilitate earlier diagnosis of HCC in this population.

A Phase I dose-escalation study of third-line regorafenib with trifluridine/tipiracil in metastatic colorectal cancer.

Aim: To determine a recommended Phase II dose of the oral fluoropyrimidine trifluridine/tipiracil (FTD/TPI) combined with the multi-kinase inhibitor regorafenib (REG) in refractory metastatic colorectal cancer patients. Materials & methods: A conventional 3 + 3 dose finding design was used. FTD/TPI was administered on days 1-5 and 8-12 of a 28-day cycle, REG on days 2-22. Two dose levels were used: FTD/TPI 25 mg/m2 b.i.d. + REG 120 mg/d, then escalated to FTD/TPI 35 mg/m2 b.i.d. + REG 120 mg/d. Results: In total, 12 patients were treated at two dose levels. Three dose-limiting toxicities were observed; all were grade 3 hypertension causally attributed to REG. Recommended Phase II dose is FTD/TPI 25 mg/m2 b.i.d. + REG 120 mg/d. Median progression-free survival was 3.81 months (95% CI: 1.51-5.29), median OS 11.1 months (95% CI: 2.3-18.2). Conclusion: The combination of REG and FTD/TPI is feasible and safe. Efficacy signals exceed that of the single agents at acceptable toxicity levels and are clinically meaningful.

Lay abstract Many patients with metastatic colorectal cancer need a sequence of different treatments over time. Regorafenib and trifluridine/tipiracil (also called TAS-102) are two drugs which are both used late in this sequence of treatments, but there is no rule as to which should be used first. Both drugs have very different mechanisms of action, and it might be beneficial to patients to administer them both at the same time as a combination treatment, instead of sequential treatment. We therefore conducted a Phase Ib study with a small number of patients to investigate whether this combined treatment would be feasible and safe. The study was designed to test the drug combination at different doses, and we found that treatment with trifluridine/tipiracil at 25 mg/m² twice daily combined with regorafenib at 120 mg daily had acceptable side effects and is likely to be safe for use in future clinical trials. Efficacy results suggest that combined treatment with both drugs may extend patient's life span. However, these observations are preliminary and need testing in further clinical trials. Clinical trial registration: EudraCT 2016-001968-11; NCT03305913 (ClinicalTrials.gov).