Interaction between tumor cells and immune cells in the tumor microenvironment is important in cancer development. Immune cells interact with the tumor cells to shape this process. Here, we use ...single-cell RNA sequencing analysis to delineate the immune landscape and tumor heterogeneity in a cohort of patients with HBV-associated human hepatocellular carcinoma (HCC). We found that tumor-associated macrophages suppress tumor T cell infiltration and TIGIT-NECTIN2 interaction regulates the immunosuppressive environment. The cell state transition of immune cells towards a more immunosuppressive and exhaustive status exemplifies the overall cancer-promoting immunocellular landscape. Furthermore, the heterogeneity of global molecular profiles reveals co-existence of intra-tumoral and inter-tumoral heterogeneity, but is more apparent in the latter. This analysis of the immunosuppressive landscape and intercellular interactions provides mechanistic information for the design of efficacious immune-oncology treatments in hepatocellular carcinoma.
Wnt/β‐catenin signaling is activated in CD133 liver cancer stem cells (CSCs), a subset of cells known to be a root of tumor recurrence and therapy resistance in hepatocellular carcinoma (HCC). ...However, the regulatory mechanism of this pathway in CSCs remains unclear. Here, we show that human microRNA (miRNA), miR‐1246, promotes cancer stemness, including self‐renewal, drug resistance, tumorigencity, and metastasis, by activation of the Wnt/β‐catenin pathway through suppressing the expression of AXIN2 and glycogen synthase kinase 3β (GSK3β), two key members of the β‐catenin destruction complex. Clinically, high endogenous and circulating miR‐1246 was identified in HCC clinical samples and correlated with a worse prognosis. Further functional analysis identified octamer 4 (Oct4) to be the direct upstream regulator of miR‐1246, which cooperatively drive β‐catenin activation in liver CSCs. Conclusion: These findings uncover the noncanonical regulation of Wnt/β‐catenin in liver CSCs by the Oct4/miR‐1246 signaling axis, and also provide a novel diagnostic marker as well as therapeutic intervention for HCC. (Hepatology 2016;64:2062‐2076).
Hepatocellular carcinoma (HCC) is heterogeneous, rendering its current curative treatments ineffective. The emergence of single-cell genomics represents a powerful strategy in delineating the complex ...molecular landscapes of cancers. In this study, we demonstrated the feasibility and merit of using single-cell RNA sequencing to dissect the intra-tumoral heterogeneity and analyze the single-cell transcriptomic landscape to detect rare cell subpopulations of significance. Exploration of the inter-relationship among liver cancer stem cell markers showed two distinct major cell populations according to EPCAM expression, and the EPCAM+ cells had upregulated expression of multiple oncogenes. We also identified a CD24+/CD44+-enriched cell subpopulation within the EPCAM+ cells which had specific signature genes and might indicate a novel stemness-related cell subclone in HCC. Notably, knockdown of signature gene CTSE for CD24+/CD44+ cells significantly reduced self-renewal ability on HCC cells in vitro and the stemness-related role of CTSE was further confirmed by in vivo tumorigenicity assays in nude mice. In summary, single-cell genomics is a useful tool to delineate HCC intratumoral heterogeneity at better resolution. It can identify rare but important cell subpopulations, and may guide better precision medicine in the long run.
•Single-cell transcriptomics dissected the intra-tumoral heterogeneity of hepatocellular carcinoma (HCC).•HCC single cells showed two distinct major cell populations according to EPCAM expression.•CD24+/CD44+-enriched cell subpopulation was identified within the EPCAM+ cells.•CTSE was the most upregulated signature gene in CD24+/CD44+-enriched cells.•Knockdown of CTSE significantly reduced self-renewal ability in vitro and tumorigenicity in vivo.
Hepatocellular carcinoma (HCC) is one of the most prevalent and lethal cancers worldwide which lacks effective treatment. Cancer cells experience high levels of oxidative stress due to increased ...generation of reactive oxygen species (ROS). Increased antioxidant‐producing capacity is therefore found in cancer cells to counteract oxidative stress. The thioredoxin system is a ubiquitous mammalian antioxidant system which scavenges ROS, and we demonstrate that it is vital for HCC growth as it maintains intracellular reduction‐oxidation (redox) homeostasis. Transcriptome sequencing in human HCC samples revealed significant overexpression of thioredoxin reductase 1 (TXNRD1), the cytosolic subunit and key enzyme of the thioredoxin system, with significant correlations to poorer clinicopathological features and patient survival. Driven by the transcriptional activation of nuclear factor (erythroid‐derived 2)–like 2, the master protector against oxidative stress, TXNRD1 counteracts intracellular ROS produced in human HCC. Inhibition of TXNRD1 through genetic inhibition hindered the proliferation of HCC cells and induced apoptosis in vitro. Administration of the pharmacological TXNRD1 inhibitor auranofin (AUR) effectively suppressed the growth of HCC tumors induced using the hydrodynamic tail vein injection and orthotopic implantation models in vivo. Furthermore, AUR sensitized HCC cells toward the conventional therapeutic sorafenib. Conclusion: Our study highlights the reliance of HCC cells on antioxidants for redox homeostasis and growth advantage; targeting TXNRD1 resulted in dramatic accumulation of ROS, which was found to be an effective approach for the suppression of HCC tumor growth.
Introduction
The ability to stratify the difficulty of minimally invasive liver resection (MILR) allows surgeons at different phases of the learning curve to tackle cases of appropriate difficulty ...safely. Several difficulty scoring systems (DSS) have been formulated which attempt to accurately stratify this difficulty. The present study aims to review the literature pertaining to the existing DSS for MILR.
Methods
We performed a systematic review and metanalysis of the literature reporting on the formulation, supporting data, and comparison of DSS for MILR.
Results
A total of 11 studies were identified which reported on the formulation of unique DSS for MILR. Five of these (Ban, Iwate, Hasegawa, Institut Mutaliste Montsouris IMM, and Southampton DSS) were externally validated and shown to predict difficulty of MILR via a range of outcome measures. The Ban DSS was supported by pooled data from 10 studies (9 LLR, 1 RLR), Iwate by 10 studies (8 LLR, 2 RLR), Hasegawa by four studies (all LLR), IMM by eight studies (all LLR), and Southampton by five studies (all LLR). There was no clear superior DSS.
Conclusion
The existing DSS were all effective in predicting difficulty of MILR. Present studies comparing between DSS have not established a clear superior system, and the five main DSS have been found to be predictive of difficulty in LLR and two of these in RLR.
Background and Aims
There are no prospective data on stereotactic body radiation therapy (SBRT) as a bridge to liver transplantation for HCC. This study aimed to evaluate the efficacy and safety of ...SBRT as bridging therapy, with comparison with transarterial chemoembolization (TACE) and high‐intensity focused ultrasound (HIFU).
Approach and Results
Patients were prospectively enrolled for SBRT under a standardized protocol from July 2015 and compared with a retrospective cohort of patients who underwent TACE or HIFU from 2010. The primary endpoint was tumor control rate at 1 year after bridging therapy. Secondary endpoints included cumulative incidence of dropout, toxicity, and posttransplant survival.
During the study period, 150 patients were evaluated (SBRT, n = 40; TACE, n = 59; HIFU, n = 51). The tumor control rate at 1 year was significantly higher after SBRT compared with TACE and HIFU (92.3%, 43.5%, and 33.3%, respectively; P = 0.02). With competing risk analysis, the cumulative incidence of dropout at 1 and 3 years after listing was lower after SBRT (15.1% and 23.3%) compared with TACE (28.9% and 45.8%; P = 0.034) and HIFU (33.3% and 45.1%; P = 0.032). Time‐to‐progression at 1 and 3 years was also superior after SBRT (10.8%, 18.5% in SBRT, 45%, 54.9% in TACE, and 47.6%, 62.8% in HIFU; P < 0.001). The periprocedural toxicity was similar, without any difference in perioperative complications and patient and recurrence‐free survival rates after transplant. Pathological complete response was more frequent after SBRT compared with TACE and HIFU (48.1% vs. 25% vs. 17.9%, respectively; P = 0.037). In multivariable analysis, tumor size <3 cm, listing alpha‐fetoprotein <200 ng/mL, Child A, and SBRT significantly reduced the risk of dropout.
Conclusions
SBRT was safe, with a significantly higher tumor control rate, reduced the risk of waitlist dropout, and should be used as an alternative to conventional bridging therapies.
Long‐term antiviral prophylaxis is required to prevent hepatitis B recurrence for patients with chronic hepatitis B after liver transplantation. We determined the long‐term outcome of 265 consecutive ...chronic hepatitis B liver transplant recipients treated with entecavir monotherapy without hepatitis B immune globulin. Viral serology, viral load, and liver biochemistry were performed at regular intervals during follow‐up. The median duration of follow‐up was 59 months. The cumulative rates of hepatitis B surface antigen (HBsAg) seroclearance were 90% and 95% at 1 and 5 years, respectively. At 1, 3, 5, and 8 years, 85%, 88%, 87.0%, and 92% were negative for HBsAg, respectively, and 95%, 99%, 100%, and 100% had undetectable hepatitis B virus (HBV) DNA, respectively. Fourteen patients remained persistently positive for HBsAg, all of whom had undetectable HBV DNA. There was no significant difference in liver stiffness for those who remained HBsAg‐positive compared to those who achieved HBsAg seroclearance (5.5 versus 5.2 kPa, respectively; P = 0.52). The overall 9‐year survival was 85%. There were 37 deaths during the follow‐up period, of which none were due to hepatitis B recurrence. Conclusion: Long‐term entecavir monotherapy is highly effective at preventing HBV reactivation after liver transplantation for chronic hepatitis B, with a durable HBsAg seroclearance rate of 92%, an undetectable HBV DNA rate of 100% at 8 years, and excellent long‐term survival of 85% at 9 years. (Hepatology 2017;66:1036‐1044).
Background and Aims
Previous recommendations suggested living donor liver transplantation (LDLT) should not be considered for patients with Model for End‐Stage Liver Disease (MELD) > 25 and ...hepatorenal syndrome (HRS).
Approach and Results
Patients who were listed with MELD > 25 from 2008 to 2017 were analyzed with intention‐to‐treat (ITT) basis retrospectively. Patients who had a potential live donor were analyzed as ITT‐LDLT, whereas those who had none belonged to ITT‐deceased donor liver transplantation (DDLT) group. ITT‐overall survival (OS) was analyzed from the time of listing. Three hundred twenty‐five patients were listed (ITT‐LDLT n = 212, ITT‐DDLT n = 113). The risk of delist/death was lower in the ITT‐LDLT group (43.4% vs. 19.8%, P < 0.001), whereas the transplant rate was higher in the ITT‐LDLT group (78.3% vs. 52.2%, P < 0.001). The 5‐year ITT‐OS was superior in the ITT‐LDLT group (72.6% vs. 49.5%, P < 0.001) for patients with MELD > 25 and patients with both MELD > 25 and HRS (56% vs. 33.8%, P < 0.001). Waitlist mortality was the highest early after listing, and the distinct alteration of slope at survival curve showed that the benefits of ITT‐LDLT occurred within the first month after listing. Perioperative outcomes and 5‐year patient survival were comparable for patients with MELD > 25 (88% vs. 85.4%, P = 0.279) and patients with both MELD > 25 and HRS (77% vs. 76.4%, P = 0.701) after LDLT and DDLT, respectively. The LDLT group has a higher rate of renal recovery by 1 month (77.4% vs. 59.1%, P = 0.003) and 3 months (86.1% vs, 74.5%, P = 0.029), whereas the long‐term estimated glomerular filtration rate (eGFR) was similar between the 2 groups. ITT‐LDLT reduced the hazard of mortality (hazard ratio = 0.387‐0.552) across all MELD strata.
Conclusions
The ITT‐LDLT reduced waitlist mortality and allowed an earlier access to transplant. LDLT in patients with high MELD/HRS was feasible, and they had similar perioperative outcomes and better renal recovery, whereas the long‐term survival and eGFR were comparable with DDLT. LDLT should be considered for patients with high MELD/HRS, and the application of LDLT should not be restricted with a MELD cutoff.
Understanding the factors that contribute to efficient SARS-CoV-2 infection of human cells may provide insights on SARS-CoV-2 transmissibility and pathogenesis, and reveal targets of intervention. ...Here, we analyze host and viral determinants essential for efficient SARS-CoV-2 infection in both human lung epithelial cells and ex vivo human lung tissues. We identify heparan sulfate as an important attachment factor for SARS-CoV-2 infection. Next, we show that sialic acids present on ACE2 prevent efficient spike/ACE2-interaction. While SARS-CoV infection is substantially limited by the sialic acid-mediated restriction in both human lung epithelial cells and ex vivo human lung tissues, infection by SARS-CoV-2 is limited to a lesser extent. We further demonstrate that the furin-like cleavage site in SARS-CoV-2 spike is required for efficient virus replication in human lung but not intestinal tissues. These findings provide insights on the efficient SARS-CoV-2 infection of human lungs.
Background & Aims We investigated the efficacy of entecavir, a cyclopentyl guanosine nucleoside analogue, as monoprophylaxis in patients with chronic hepatitis B who received a liver transplant. ...Methods We studied data from 80 consecutive patients who received a liver transplant (47 from living donors and 33 from deceased donors) for hepatitis B–related disease and entecavir monotherapy as prophylaxis. None of the patients received hepatitis B immunoglobulin. Indications for transplant included decompensation from cirrhosis (27.5%), acute-on-chronic hepatitis B (47.5%), and hepatocellular carcinoma (25%). The median follow-up time was 26 months (range, 5–40 months). Before transplant, 33 patients were not on antiviral therapy and 47 were on oral therapy (18 had received less than 3 months of treatment). Results At the time of transplant, the median log HBV DNA level was 3.5 copies/mL (range, 1.54–8.81); 21 patients (26%) had undetectable levels of HBV DNA. The cumulative rate of hepatitis B surface antigen (HBsAg) loss was 86% and 91% after 1 and 2 years, respectively. Ten patients had reappearance of HBsAg. Eighteen patients (22.5%) were HBsAg positive at the time of their last examination; 17 of these had undetectable levels of HBV DNA, and the remaining patient had a low level of HBV DNA (217 copies/mL). There was no evidence of mutations at sites that confer resistance to entecavir among patients who were HBsAg positive. Conclusions Although only 26% of patients had complete viral suppression at the time of transplant, 91% lost HBsAg, with 98.8% achieving undetectable levels of HBV DNA. A hepatitis B immunoglobulin–free regimen of entecavir monotherapy is effective after liver transplantation for chronic hepatitis B.
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