Stem cell markers, including NANOG, have been implicated in various cancers; however, the functional contribution of NANOG to cancer pathogenesis has remained unclear. Here, we show that NANOG is ...induced by Toll-like receptor 4 (TLR4) signaling via phosphorylation of E2F1 and that downregulation of Nanog slows down hepatocellular carcinoma (HCC) progression induced by alcohol western diet and hepatitis C virus protein in mice. NANOG ChIP-seq analyses reveal that NANOG regulates the expression of genes involved in mitochondrial metabolic pathways required to maintain tumor-initiating stem-like cells (TICs). NANOG represses mitochondrial oxidative phosphorylation (OXPHOS) genes, as well as ROS generation, and activates fatty acid oxidation (FAO) to support TIC self-renewal and drug resistance. Restoration of OXPHOS activity and inhibition of FAO renders TICs susceptible to a standard care chemotherapy drug for HCC, sorafenib. This study provides insights into the mechanisms of NANOG-mediated generation of TICs, tumorigenesis, and chemoresistance through reprogramming of mitochondrial metabolism.
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•Stem cell marker NANOG is activated by the TLR4-E2F1 pathway•NANOG ChIP-seq identifies target genes involved in OXPHOS and FAO•Nanog represses OXPHOS and mitochondrial ROS in TICs•Restoration of OXPHOS and inhibition of FAO restores TIC susceptibility to drugs
Chen et al. show that the pluripotency transcription factor NANOG contributes to liver cancer progression by reprogramming mitochondrial metabolism to promote self-renewal ability, tumor-initiation property, and chemoresistance of tumor-initiating stem-like cells (TICs). Restoration of OXPHOS activity and inhibition of fatty acid oxidation restores TIC susceptibility to chemotherapy drugs.
Abstract
The detection of tumor-derived cell-free DNA in plasma is one of the most promising directions in cancer diagnosis. The major challenge in such an approach is how to identify the tiny amount ...of tumor DNAs out of total cell-free DNAs in blood. Here we propose an ultrasensitive cancer detection method, termed 'CancerDetector', using the DNA methylation profiles of cell-free DNAs. The key of our method is to probabilistically model the joint methylation states of multiple adjacent CpG sites on an individual sequencing read, in order to exploit the pervasive nature of DNA methylation for signal amplification. Therefore, CancerDetector can sensitively identify a trace amount of tumor cfDNAs in plasma, at the level of individual reads. We evaluated CancerDetector on the simulated data, and showed a high concordance of the predicted and true tumor fraction. Testing CancerDetector on real plasma data demonstrated its high sensitivity and specificity in detecting tumor cfDNAs. In addition, the predicted tumor fraction showed great consistency with tumor size and survival outcome. Note that all of those testing were performed on sequencing data at low to medium coverage (1× to 10×). Therefore, CancerDetector holds the great potential to detect cancer early and cost-effectively.
Background Local hemostatic agents are important for the control of bleeding during liver resection when standard surgical techniques are insufficient. Study Design This was a multicenter, ...randomized, open-label study to compare fibrin sealant patch (FSP; TachoSil; Takeda Pharma A/S) with oxidized regenerated cellulose gauze (ORCG; Surgicel Original; Ethicon) for the secondary treatment of local bleeding after hepatic resection in adult and pediatric patients. Primary end point was the proportion of adult patients with intraoperative hemostasis at the target bleeding site within 3 minutes of application of treatment. Results Of 321 adult patients screened, 224 patients had minor to moderate bleeding from the hepatic resection area after primary hemostatic treatment and were intraoperatively randomized to FSP (n = 114) or ORCG (n = 110). Hemostasis within 3 minutes was achieved in 92 patients in the FSP group (80.7%) and 55 patients in the ORCG group (50.0%) (odds ratio = 4.87; 95% CI, 2.55–9.29; p < 0.001). The proportion of patients with hemostasis at 5 minutes was also higher in the FSP group (94.7% vs 76.4%; odds ratio = 6.24; 95% CI, 2.39–16.30; p < 0.001), and time to hemostasis was shorter (p < 0.001). At 10 minutes, hemostasis was achieved in all patients in the FSP group and 12 patients in the ORCG group (10.9%) had visible bleeding and required hemostatic rescue therapy. In pediatric patients, hemostasis at 3 minutes was achieved in 17 of 20 (85.0%) patients with FSP and 4 of 9 (44.4%) patients with ORCG. Both treatments were well tolerated in adults and children. Conclusions The FSP (TachoSil) was safe and superior to ORCG (Surgicel Original) for achieving hemostasis in patients undergoing hepatic resection. ClinicalTrials.gov ID NCT01192022.
The coronavirus disease 2019 (COVID-19) pandemic has brought most ongoing clinical trials to a standstill, while at the same time emphasizing the need for new therapeutic treatments and strategies to ...mitigate the morbidity and mortality related to COVID-19. Recent publication of several observational studies has generated much discussion surrounding efficacy of drugs including hydroxychloroquine, azithromycin, and remdesivir, stressing the need for high-quality prospective, randomized control trials in patients with COVID-19. Ongoing “stay at home” orders and institutional policies mandating “work from home” for nonessential employees, which includes most research personnel, have impacted the ability to implement and conduct clinical studies. This article discusses the approach of an experienced clinical trials unit to make adjustments for ongoing studies and ensure the safety of study participants. At the same time, plans were implemented to continue collection of data to achieve endpoints, safely enroll and follow participants in studies offering potential benefit, and quickly implement new COVID-19 clinical trials. The existence of a Division of Clinical Research with regulatory, budgeting, contracting, and coordinating expertise within a department of surgery can successfully accommodate a crisis situation and rapidly adapt to new requirements for the safe, efficient, and effective conversion to a remote work force without compromising the research process.
As the novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has emerged as a viral pandemic, data on the clinical characteristics and outcomes of patients with SARS-CoV-2 ...infection undergoing solid organ transplant are emerging. The objective of this systematic review was to assess currently published literature relating to the management, clinical course, and outcome of SARS-CoV-2 infection in liver, kidney, and heart solid organ transplant recipients.
We conducted a systematic review to assess currently published literature relating to the management, clinical course, and outcome of SARS-CoV-2 infection in liver, kidney, and heart solid organ transplant recipients. Articles published through June 2020 were searched in the MEDLINE, ClinicalTrials.gov, and PubMed databases. We identified 49 eligible studies comprising a total of 403 solid organ transplant recipients.
Older age, male sex, and preexisting comorbidities, including hypertension and/or diabetes, were the most common prevailing characteristics among the solid organ transplant recipients. Clinical presentation ranged from mild to severe disease, including multiorgan failure and death. We found an overall mortality rate of 21%.
Our analysis suggests no increase in overall mortality or worse outcome in solid organ transplant recipients receiving immunosuppressive therapy compared with mortality in the general surgical population with SARS-CoV-2. Our findings suggest that transplant surgery and its immunosuppressive effects should not be a deterrent to proper surgical care for patients in the SARS-CoV-2 era.
Drug resistance is a major problem in the treatment of liver cancer. Mammalian Target of Rapamycin 1 (mTORC1) inhibitors have been tested for the treatment of liver cancer based on hyperactive mTOR ...in this malignancy. However, their clinical trials showed poor outcome, most likely due to their ability to upregulate CD133 and promote chemoresistance. The CD133+ tumor–initiating stem cell–like cells (TICs) isolated from mouse and human liver tumors are chemoresistant, and identification of an approach to abrogate this resistance is desired. In search of a compound that rescinds resistance of TICs to mTORC1 inhibition and improves chemotherapy, we identified baicalein (BC), which selectively chemosensitizes TICs and the human hepatocellular carcinoma (HCC) cell line Huh7 cells but not mouse and human primary hepatocytes. Nanobead pull‐down and mass‐spectrometric analysis, biochemical binding assay, and three‐dimensional computational modeling studies reveal BC's ability to competitively inhibit guanosine triphosphate binding of SAR1B guanosine triphosphatase, which is essential for autophagy. Indeed, BC suppresses autophagy induced by an mTORC1 inhibitor and synergizes cell death caused by mTORC1 inhibition in TIC and Huh7 spheroid formation and in the patient‐derived xenograft model of HCC. The BC‐induced chemosensitization is rescued by SAR1B expression and phenocopied by SAR1B knockdown in cancer cells treated with a mTORC1 inhibitor. Conclusion: These results identify SAR1B as a target in liver TICs and HCC cells resistant to mTORC1 inhibition.
Background & Aims Obesity and alcohol consumption contribute to steatohepatitis, which increases the risk for hepatitis C virus (HCV)-associated hepatocellular carcinomas (HCCs). Mouse hepatocytes ...that express HCV-NS5A in liver up-regulate the expression of Toll-like receptor 4 (TLR4), and develop liver tumors containing tumor-initiating stem-like cells (TICs) that express NANOG. We investigated whether the TLR4 signals to NANOG to promote the development of TICs and tumorigenesis in mice placed on a Western diet high in cholesterol and saturated fat (HCFD). Methods We expressed HCV-NS5A from a transgene (NS5A Tg) in Tlr4 -/- (C57Bl6/10ScN), and wild-type control mice. Mice were fed a HCFD for 12 months. TICs were identified and isolated based on being CD133+, CD49f+, and CD45-. We obtained 142 paraffin-embedded sections of different stage HCCs and adjacent nontumor areas from the same patients, and performed gene expression, immunofluorescence, and immunohistochemical analyses. Results A higher proportion of NS5A Tg mice developed liver tumors (39%) than mice that did not express HCV NS5A after the HCFD (6%); only 9% of Tlr4 -/- NS5A Tg mice fed HCFD developed liver tumors. Livers from NS5A Tg mice fed the HCFD had increased levels of TLR4, NANOG, phosphorylated signal transducer and activator of transcription (pSTAT3), and TWIST1 proteins, and increases in Tlr4 , Nanog , Stat3 , and Twist1 messenger RNAs. In TICs from NS5A Tg mice, NANOG and pSTAT3 directly interact to activate expression of Twist1 . Levels of TLR4, NANOG, pSTAT3, and TWIST were increased in HCC compared with nontumor tissues from patients. Conclusions HCFD and HCV-NS5A together stimulated TLR4-NANOG and the leptin receptor (OB-R)-pSTAT3 signaling pathways, resulting in liver tumorigenesis through an exaggerated mesenchymal phenotype with prominent Twist1 -expressing TICs.
Severe alcoholic hepatitis (sAH) is associated with a poor prognosis. There is no proven effective treatment for sAH, which is why early transplantation has been increasingly discussed. ...Hepatoblastoma‐derived C3A cells express anti‐inflammatory proteins and growth factors and were tested in an extracorporeal cellular therapy (ELAD) study to establish their effect on survival for subjects with sAH. Adults with sAH, bilirubin ≥8 mg/dL, Maddrey's discriminant function ≥ 32, and Model for End‐Stage Liver Disease (MELD) score ≤ 35 were randomized to receive standard of care (SOC) only or 3‐5 days of continuous ELAD treatment plus SOC. After a minimum follow‐up of 91 days, overall survival (OS) was assessed by using a Kaplan‐Meier survival analysis. A total of 203 subjects were enrolled (96 ELAD and 107 SOC) at 40 sites worldwide. Comparison of baseline characteristics showed no significant differences between groups and within subgroups. There was no significant difference in serious adverse events between the 2 groups. In an analysis of the intent‐to‐treat population, there was no difference in OS (51.0% versus 49.5%). The study failed its primary and secondary end point in a population with sAH and with a MELD ranging from 18 to 35 and no upper age limit. In the prespecified analysis of subjects with MELD < 28 (n = 120), ELAD was associated with a trend toward higher OS at 91 days (68.6% versus 53.6%; P = .08). Regression analysis identified high creatinine and international normalized ratio, but not bilirubin, as the MELD components predicting negative outcomes with ELAD. A new trial investigating a potential benefit of ELAD in younger subjects with sufficient renal function and less severe coagulopathy has been initiated. Liver Transplantation 24 380–393 2018 AASLD.
Single cell and spatially resolved 'omic' techniques have enabled deep characterization of clinical pathologies that remain poorly understood, providing unprecedented insights into molecular ...mechanisms of disease. However, transcriptomic platforms are costly, limiting sample size, which increases the possibility of pre-analytical variables such as tissue processing and storage procedures impacting RNA quality and downstream analyses. Furthermore, spatial transcriptomics have not yet reached single cell resolution, leading to the development of multiple deconvolution methods to predict individual cell types within each transcriptome 'spot' on tissue sections. In this study, we performed spatial transcriptomics and single nucleus RNA sequencing (snRNAseq) on matched specimens from patients with either histologically normal or advanced fibrosis to establish important aspects of tissue handling, data processing, and downstream analyses of biobanked liver samples. We observed that tissue preservation technique impacts transcriptomic data, especially in fibrotic liver. Single cell mapping of the spatial transcriptome using paired snRNAseq data generated a spatially resolved, single cell dataset with 24 unique liver cell phenotypes. We determined that cell-cell interactions predicted using ligand-receptor analysis of snRNAseq data poorly correlated with cellular relationships identified using spatial transcriptomics. Our study provides a framework for generating spatially resolved, single cell datasets to study gene expression and cell-cell interactions in biobanked clinical samples with advanced liver disease.
Hepatocellular carcinoma (HCC) is the 3
most deadly malignancy. Activated hepatic stellate cells (aHSC) give rise to cancer-associated fibroblasts in HCC and are considered a potential therapeutic ...target. Here we report that selective ablation of stearoyl CoA desaturase-2 (Scd2) in aHSC globally suppresses nuclear CTNNB1 and YAP1 in tumors and tumor microenvironment and prevents liver tumorigenesis in male mice. Tumor suppression is associated with reduced leukotriene B4 receptor 2 (LTB4R2) and its high affinity oxylipin ligand, 12-hydroxyheptadecatrienoic acid (12-HHTrE). Genetic or pharmacological inhibition of LTB4R2 recapitulates CTNNB1 and YAP1 inactivation and tumor suppression in culture and in vivo. Single cell RNA sequencing identifies a subset of tumor-associated aHSC expressing Cyp1b1 but no other 12-HHTrE biosynthetic genes. aHSC release 12-HHTrE in a manner dependent on SCD and CYP1B1 and their conditioned medium reproduces the LTB4R2-mediated tumor-promoting effects of 12-HHTrE in HCC cells. CYP1B1-expressing aHSC are detected in proximity of LTB4R2-positive HCC cells and the growth of patient HCC organoids is blunted by LTB4R2 antagonism or knockdown. Collectively, our findings suggest aHSC-initiated 12-HHTrE-LTB4R2-CTNNB1-YAP1 pathway as a potential HCC therapeutic target.
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