Background and Aims
Ras‐like (Ral) small guanosine triphosphatases (GTPases), RalA and RalB, are proto‐oncogenes directly downstream of Ras and cycle between the active guanosine triphosphate‐bound ...and inactive guanosine diphosphate‐bound forms. RalGTPase‐activating protein (RalGAP) complex exerts a negative regulation. Currently, the role of Ral up‐regulation in cancers remains unclear. We aimed to examine the clinical significance, functional implications, and underlying mechanisms of RalA signaling in HCC.
Approach and Results
Our in‐house and The Cancer Genome Atlas RNA sequencing data and quantitative PCR data revealed significant up‐regulation of RalA in patients’ HCCs. Up‐regulation of RalA was associated with more aggressive tumor behavior and poorer prognosis. Consistently, knockdown of RalA in HCC cells attenuated cell proliferation and migration in vitro and tumorigenicity and metastasis in vivo. We found that RalA up‐regulation was driven by copy number gain and uncovered that SP1 and ETS proto‐oncogene 2 transcription factor cotranscriptionally drove RalA expression. On the other hand, RalGAPA2 knockdown increased the RalA activity and promoted intrahepatic and extrahepatic metastasis in vivo. Consistently, we observed significant RalGAPA2 down‐regulation in patients’ HCCs. Intriguingly, HCC tumors showing simultaneous down‐regulation of RalGAPA2 and up‐regulation of RalA displayed a significant association with more aggressive tumor behavior in terms of more frequent venous invasion, more advanced tumor stage, and poorer overall survival. Of note, Ral inhibition by a Ral‐specific inhibitor RBC8 suppressed the oncogenic functions in a dose‐dependent manner and sensitized HCC cells to sorafenib treatment, with an underlying enhanced inhibition of mammalian target of rapamycin signaling.
Conclusions
Our results provide biological insight that dysregulation of RalA signaling through dual regulatory mechanisms supports its oncogenic functions in HCC. Targeting RalA may serve as a potential alternative therapeutic approach alone or in combination with currently available therapy.
ATP-binding cassette (ABC) transporters mediate multidrug resistance and cancer stem cell properties in various model systems. Yet, their biological significance in cancers, especially in ...hepatocellular carcinoma (HCC), remains unclear. In this study, we investigated the function of ABCF1 in HCC and explored its potential as a therapeutic target. ABCF1 was highly expressed in fetal mouse livers but not in normal adult livers. ABCF1 expression was upregulated in HCCs. These results demonstrate that ABCF1 functions as a hepatic oncofetal protein. We further demonstrated elevated ABCF1 expression in HCC cells upon acquiring chemoresistance. Suppression of ABCF1 by siRNA sensitized both parental cells and chemoresistant cells to chemotherapeutic agents. Reversely, ABCF1 overexpression promoted chemoresistance and drug efflux. In addition, overexpression of ABCF1 enhanced migration, spheroid and colony formation and epithelial-mesenchymal transition (EMT) induction. RNA sequencing analysis revealed EMT inducers HIF1α/IL8 and Sox4 as potential mediators for the oncogenic effect of ABCF1 in HCC progression. Together, this study illustrates that ABCF1 is a novel potential therapeutic target for HCC treatment.
•ABC proteins mediate multidrug resistance and stem cell properties but their clinical importance in HCCs remained unclear.•ABCF1 is a hepatic oncofetal protein. Its expression is further elevated in HCC cells upon acquiring chemoresistance.•ABCF1 expression modulateschemoresponse, migration, epithelial-mesenchymal transition (EMT), and cancer stemness properties.•ABCF1 regulates EMT inducers HIF1α/IL8 and Sox4 as potential mediators for the oncogenic effect in HCC progression.•ABCF1 serves as a novel potential therapeutic target for HCC treatment.
Growing evidence indicates that tumour cells exhibit characteristics similar to their lineage progenitor cells. We found that S100 calcium binding protein A10 (S100A10) exhibited an expression ...pattern similar to that of liver progenitor genes. However, the role of S100A10 in hepatocellular carcinoma (HCC) progression is unclear. Furthermore, extracellular vesicles (EVs) are critical mediators of tumourigenesis and metastasis, but the extracellular functions of S100A10, particularly those related to EVs (EV-S100A10), are unknown.
The functions and mechanisms of S100A10 and EV-S100A10 in HCC progression were investigated in vitro and in vivo. Neutralising antibody (NA) to S100A10 was used to evaluate the significance of EV-S100A10.
Functionally, S100A10 promoted HCC initiation, self-renewal, chemoresistance and metastasis in vitro and in vivo. Of significance, we found that S100A10 was secreted by HCC cells into EVs both in vitro and in the plasma of patients with HCC. S100A10-enriched EVs enhanced the stemness and metastatic ability of HCC cells, upregulated epidermal growth factor receptor (EGFR), AKT and ERK signalling, and promoted epithelial-mesenchymal transition. EV-S100A10 also functioned as a chemoattractant in HCC cell motility. Of significance, S100A10 governed the protein cargos in EVs and mediated the binding of MMP2, fibronectin and EGF to EV membranes through physical binding with integrin αⅤ. Importantly, blockage of EV-S100A10 with S100A10-NA significantly abrogated these enhancing effects.
Altogether, our results uncovered that S100A10 promotes HCC progression significantly via its transfer in EVs and regulating the protein cargoes of EVs. EV-S100A10 may be a potential therapeutic target and biomarker for HCC progression.
The long-term outcomes of oral antiviral therapy without hepatitis B immune globulin (HBIG) in prevention of reinfection with hepatitis B after liver transplantation are not known. We aimed to ...determine the long-term outcomes from a large population of chronic hepatitis B (CHB) liver transplant recipients using oral antiviral therapy alone.
A total of 362 consecutive CHB patients transplanted from January 2003 to May 2011 were included. None of the patients received HBIG. Viral serology, viral load, and liver biochemistry were performed at regular intervals during follow-up.
Of the 362 patients, 176 (49%), 142 (39%), and 44 (12%) were on lamivudine (LAM), entecavir (ETV), and combination therapy (predominantly LAM+adefovir), respectively, at the time of transplant. The median follow-up length was 53 months. The rate of hepatitis B surface antigen seronegativity and hepatitis B virus (HBV) DNA suppression to undetectable levels at 8 years was 88 and 98%, respectively. The virological relapse rates (>1 log increase IU/ml) at 1, 3, 5, and 8 years was 5, 10, 13 and 16%, respectively. The virological relapse rate at 3 years for LAM, ETV, and combination group was 17, 0, and 7%, respectively (P<0.001). Forty-two patients had virological relapse, of which 36 had YMDD mutation (31 in the LAM group and 5 in the combination group). The overall 8-year survival was 83%, with no difference between the three treatment groups (P=0.94). No mortality from HBV recurrence occurred in the 362 patients.
Oral nucleoside/nucleotide analogs without HBIG are effective in preventing graft loss secondary to hepatitis B recurrence after liver transplantation. However, new agents with a high barrier to resistance should be used to minimize drug resistance and to prevent virological rebound.
Aberrant activation of the Notch signaling pathway is implicated in many solid tumors, including hepatocellular carcinoma, indicating a potential use of Notch inhibitors for treatment. In this study, ...we investigated the antitumor and antimetastasis efficacy of the novel Notch inhibitor (γ-secretase inhibitor) PF-03084014 in hepatocellular carcinoma. Hepatocellular carcinoma spherical cells (stem-like cancer cells), a sphere-derived orthotopic tumor model and one patient-derived xenograft (PDX) model were used in our experiment. We demonstrated that PF-03084014 inhibited the self-renewal and proliferation of cancer stem cells. PF-03084014 reduced the hepatocellular carcinoma sphere-derived orthotopic tumor and blocked the hepatocellular carcinoma tumor liver to lung metastasis. We further tested the PF-03084014 in PDX models and confirmed the inhibition tumor growth effect. In addition, a low dose of PF-03084014 induced hepatocellular carcinoma sphere differentiation, resulting in chemosensitization. Antitumor activity was associated with PF-03084014-induced suppression of Notch1 activity, decreased Stat3 activation and phosphorylation of the Akt signaling pathway, and reduced epithelial-mesenchymal transition. These are the key contributors to the maintenance of cancer stemness and the promotion of cancer metastasis. Moreover, the Notch-Stat3 association was implicated in the clinical hepatocellular carcinoma prognosis. Collectively, PF-03084014 revealed antitumor and antimetastatic effects in hepatocellular carcinoma, providing evidence for the potential use of gamma-secretase inhibitors as a therapeutic option for the treatment of hepatocellular carcinoma.
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Minimally invasive right posterior sectionectomy (RPS) is a technically challenging procedure. This study was designed to determine outcomes following robotic RPS (R-RPS) and laparoscopic RPS ...(L-RPS).
An international multicentre retrospective analysis of patients undergoing R-RPS versus those who had purely L-RPS at 21 centres from 2010 to 2019 was performed. Patient demographics, perioperative parameters, and postoperative outcomes were analysed retrospectively from a central database. Propensity score matching (PSM) was performed, with analysis of 1 : 2 and 1 : 1 matched cohorts.
Three-hundred and forty patients, including 96 who underwent R-RPS and 244 who had L-RPS, met the study criteria and were included. The median operating time was 295 minutes and there were 25 (7.4 per cent) open conversions. Ninety-seven (28.5 per cent) patients had cirrhosis and 56 (16.5 per cent) patients required blood transfusion. Overall postoperative morbidity rate was 22.1 per cent and major morbidity rate was 6.8 per cent. The median postoperative stay was 6 days. After 1 : 1 matching of 88 R-RPS and L-RPS patients, median (i.q.r.) blood loss (200 (100-400) versus 450 (200-900) ml, respectively; P < 0.001), major blood loss (> 500 ml; P = 0.001), need for intraoperative blood transfusion (10.2 versus 23.9 per cent, respectively; P = 0.014), and open conversion rate (2.3 versus 11.4 per cent, respectively; P = 0.016) were lower in the R-RPS group. Similar results were found in the 1 : 2 matched groups (66 R-RPS versus 132 L-RPS patients).
R-RPS and L-RPS can be performed in expert centres with good outcomes in well selected patients. R-RPS was associated with reduced blood loss and lower open conversion rates than L-RPS.
BACKGROUND: Chemoembolization with doxorubucin-eluting beads (DEB) has been used to treat hepatocellular carcinoma (HCC) since 2007. This study compared the efifcacy and sur-vival between ...transarterial chemoembolization (TACE) with DEB and conventional approach (cTACE) in HCC treatment. METHODS: This retrospective case-control study compared the overall survival and tumor response of HCC patients to cTACE (n=190) and DEB (n=143) by the reassessment of com-puted tomography and serum alpha-fetoprotein (AFP). Mul-tivariate analysis was used to determine the factors affecting tumor response. RESULTS: The median post-treatment to pre-treatment AFP level was 0.8 for a DEB session (n=258) and 1.0 for a cTACE session (n=452), showing a signiifcantly greater decrease in AFP after DEB (P<0.05). More patients in the DEB group achieved objective response (complete and partial) compared with those in the cTACE group (P<0.05). Objective tumor re-sponse after DEB vs cTACE was 34.8% vs 15.4% in 0-3 months (P=0.001), 37.1% vs 20.0% in 3-6 months (P<0.05), and 50.0%vs 30.0% in 6-12 months (P=0.093). DEB predicted a 3.604 times odds of achieving at least one objective tumor response in a patient when compared to cTACE (P<0.0001). The median survival from ifrst transcatheter therapy of patients having undergone at least once DEB was 12.53 months, while those having received cTACE only was 10.53 months (P=0.086). A tendency of improved survival appeared to maintain until >80 months after the ifrst TACE session in the DEB group. CONCLUSION: DEB is a safe alternative to cTACE in HCC pa-tients with better therapeutic efifcacy.
Background: Hepatocellular carcinoma (HCC) is highly prevalent in Hong Kong due to the high prevalence of chronic hepatitis B infection. Liver cancer is the fourth most common cancer and the third ...most common cause of cancer death. Due to the high case load, there is a high level of local expertise in treating HCC, and the full spectrum of treatment modalities is available. This document summarizes how these modalities should be used based on the latest evidence. Summary: In 2 meetings held in early 2017, a multidisciplinary group of Hong Kong clinicians, including liver surgeons, interventional radiologists, clinical oncologists, and medical oncologists, met to update local consensus statements for management of HCC. These statements are based on the latest evidence and give detailed guidance on how to deploy these modalities, in particular for cases of HCC which are not suited to surgical resection. Key Messages: These statements give detailed information on how to decide if a patient is a candidate for resection, methods to improve candidacy for resection, and guidance for use of various nonsurgical interventions to manage patients ineligible for resection.
Background and Aims
Hepatitis B virus (HBV) integrations are common in hepatocellular carcinoma (HCC). In particular, alterations of the telomerase reverse transcriptase (TERT) gene by HBV ...integrations are frequent; however, the molecular mechanism and functional consequence underlying TERT HBV integration are unclear.
Approach and Results
We adopted a targeted sequencing strategy to survey HBV integrations in human HBV‐associated HCCs (n = 95). HBV integration at the TERT promoter was frequent (35.8%, n = 34/95) in HCC tumors and was associated with increased TERT mRNA expression and more aggressive tumor behavior. To investigate the functional importance of various integrated HBV components, we employed different luciferase reporter constructs and found that HBV enhancer I (EnhI) was the key viral component leading to TERT activation on integration at the TERT promoter. In addition, the orientation of the HBV integration at the TERT promoter further modulated the degree of TERT transcription activation in HCC cell lines and patients’ HCCs. Furthermore, we performed array‐based small interfering RNA library functional screening to interrogate the potential major transcription factors that physically interacted with HBV and investigated the cis‐activation of host TERT gene transcription on viral integration. We identified a molecular mechanism of TERT activation through the E74 like ETS transcription factor 4 (ELF4), which normally could drive HBV gene transcription. ELF4 bound to the chimeric HBV EnhI at the TERT promoter, resulting in telomerase activation. Stable knockdown of ELF4 significantly reduced the TERT expression and sphere‐forming ability in HCC cells.
Conclusions
Our results reveal a cis‐activating mechanism harnessing host ELF4 and HBV integrated at the TERT promoter and uncover how TERT HBV‐integrated HCCs may achieve TERT activation in hepatocarcinogenesis.
Background
Previous studies comparing outcomes of hepatocellular carcinoma (HCC) patients after living donor liver transplantation (LDLT) and deceased donor liver transplantation (DDLT) showed ...conflicting results, and most studies measured survival outcomes from the time of liver transplantation (LT).
Method
This retrospective study was aimed to evaluate the long-term outcomes of HCC patients listed for LT using intention-to-treat (ITT) and propensity score matching (PSM) analyses. Clinicopathological data were retrieved from a prospectively collected database.
Results
From 1995 to 2014, 375 HCC patients were listed for LT. ITT-LDLT group had 188 patients, whereas ITT-DDLT group had 187 patients. Twenty-seven patients (14.4%) and 122 patients (65.2%) were delisted from LDLT and DDLT waitlist, respectively. The 1-, 3- and 5-year overall survival rates were significantly better in ITT-LDLT group than ITT-DDLT group (94.1 vs. 77.5%, 81.4 vs. 48.7% and 75.9 vs. 40.8%). High alphafetoprotein (AFP) and ITT-DDLT treatment arm were independent poor prognostic factors affecting overall survival. LDLT group (
n
= 161) had more young patients, poorer liver function, higher AFP, more tumors outside Milan/UCSF criteria, when compared with DDLT group (
n
= 85). After PSM, the 1-, 3- and 5-year overall (95.4 vs. 98.5%, 80.0 vs. 92.3% and 73.4 vs. 84.4%) and recurrence-free (87.7% vs. 90.8%, 76.9% vs. 83.1% and 72.2% vs. 81.5%) survival rates were comparable between the matched LDLT and the matched DDLT group, respectively.
Conclusion
Survival benefit of LDLT was observed for HCC patients with ITT analysis. Despite a more advanced tumor stage, overall and recurrence-free survival rates were comparable between LDLT and DDLT using PSM analysis.
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