Ischemia-reperfusion of small liver remnant promotes liver tumor growth and metastases--activation of cell invasion and migration pathways

Partial Hepatectomy Promotes the Development of KRASG12V-Induced Hepatocellular Carcinoma in Zebrafish

The purpose of this study was to investigate the effects of PH on the development of oncogenic krasG12V-induced HCC in zebrafish. The inducible HCC model in Tg(fabp10a:rtTA2s-M2; TRE2:EGFP-krasG12V) zebrafish was used. PH or sham surgery was performed before the induction of oncogenic krasG12V expression in the livers of transgenic zebrafish. Histological analysis was carried out to determine the progression of HCC and other HCC-associated features including hepatocyte proliferation, extracellular matrix production, and local oxidative stress. The similarity between the process of PH-induced liver regeneration and that of krasG12V-induced HCC development was further compared by RNA-Seq analysis. The results show that PH promotes the development of krasG12V-induced HCC in zebrafish possibly through enhancing neutrophil-mediated oxidative stress and promoting the upregulation of s100a1, and the downregulation of ribosome biogenesis.

Effect of Pringle maneuver on prognosis of patients with colorectal cancer liver metastases after liver resection: a meta-analysis

PURPOSE

Pringle maneuver (PM) is a double-edged sword in liver resection, which is beneficial in reducing blood loss but also causes ischemia-reperfusion injury which may stimulate the outgrowth of micrometastases. The impact of PM on tumor recurrence remains controversial. This study aimed to assess whether PM has effect on the prognosis of colorectal cancer liver metastases (CRLM) after hepatectomy.

METHODS

PubMed and the Cochrane Library databases were searched. The PM is defined as the portal triad clamping for several minutes, followed by several minutes of reperfusion, repeated as needed. Prolonged PM was defined as continuous clamping ≥ 20 min or ≥ 3 cycles for maximally 15-min intermittent ischemia.

RESULTS

Eleven studies encompassing 4054 patients were included in this meta-analysis. The pooled hazard ratio (HR) did not show significant differences between PM and non-PM groups for disease-free survival (DFS) (HR = 0.91, 95% confidence interval (CI) 0.76-1.11, P = 0.36) and overall survival (HR = 1.03, 95% CI 0.76-1.39, P = 0.87). Subgroup analysis revealed that prolonged PM has adverse impact on DFS (HR 1.75, 95% CI = 1.28-2.40, P = 0.0005). However, non-prolonged PM is a protective factor for DFS (HR 0.82, 95% CI = 0.73-0.92, P = 0.001).

CONCLUSION

These findings suggested that prolonged PM may have an adverse impact on the DFS of patients with CRLM and non-prolonged PM is a protective factor for DFS. Further prospective multicenter studies are warranted.

The role of ischaemia-reperfusion injury and liver regeneration in hepatic tumour recurrence

The risk of cancer recurrence after liver surgery mainly depends on tumour biology, but preclinical and clinical evidence suggests that the degree of perioperative liver injury plays a role in creating a favourable microenvironment for tumour cell engraftment or proliferation of dormant micro-metastases. Understanding the contribution of perioperative liver injury to tumour recurrence is imperative, as these pathways are potentially actionable. In this review, we examine the key mechanisms of perioperative liver injury, which comprise mechanical handling and surgical stress, ischaemia-reperfusion injury, and parenchymal loss leading to liver regeneration. We explore how these processes can trigger downstream cascades leading to the activation of the immune system and the pro-inflammatory response, cellular proliferation, angiogenesis, anti-apoptotic signals, and release of circulating tumour cells. Finally, we discuss the novel therapies under investigation to decrease ischaemia-reperfusion injury and increase regeneration after liver surgery, including pharmaceutical agents, inflow modulation, and machine perfusion.

The tumor microenvironment in the postsurgical liver: Mechanisms and potential targets of postoperative recurrence in human hepatocellular carcinoma

Surgery remains to be the mainstay of treatment for hepatocellular carcinoma (HCC). Nonetheless, its therapeutic efficacy is significantly impaired by postoperative recurrence, which occurs in more than half of cases as a result of intrahepatic metastasis or de novo tumorigenesis. For decades, most therapeutic strategies on inhibiting postoperative HCC recurrence have been focused on the residual tumor cells but satisfying therapeutic outcomes are barely observed in the clinic. In recent years, a better understanding of tumor biology allows us to shift our focus from tumor cells toward the postoperative tumor microenvironment (TME), which is gradually identified to play a pivotal role in tumor recurrence. In this review, we describe various surgical stress and surgical perturbation on postoperative TME. Besides, we discuss how such alternations in TME give rise to postoperative recurrence of HCC. Based on its clinical significance, we additionally highlight the potential of the postoperative TME as a target for postoperative adjuvant therapeutics.

Impact of Hypothermic Oxygenated Machine Perfusion on Hepatocellular Carcinoma Recurrence after Liver Transplantation

BACKGROUND

Machine perfusion may be able to mitigate ischemia-reperfusion injury (IRI), which increases hepatocellular carcinoma (HCC) recurrence after liver transplantation (LT). This study aimed to investigate the impact of dual-hypothermic oxygenated machine perfusion (D-HOPE) on HCC recurrence in LT.

METHODS

A single-center retrospective study was conducted from 2016 to 2020. Pre- and postoperative data of HCC patients undergoing LT were analyzed. Recipients of a D-HOPE-treated graft were compared to those of livers preserved using static cold storage (SCS). The primary endpoint was recurrence-free survival (RFS).

RESULTS

Of 326 patients, 246 received an SCS-preserved liver and 80 received a D-HOPE-treated graft (donation after brain death (DBD), n = 66; donation after circulatory death (DCD), n = 14). Donors of D-HOPE-treated grafts were older and had higher BMI. All DCD donors were treated by normothermic regional perfusion and D-HOPE. The groups were comparable in terms of HCC features and estimated 5-year RFS according to the Metroticket 2.0 model. D-HOPE did not reduce HCC recurrence (D-HOPE 10%; SCS 8.9%; p = 0.95), which was confirmed using Bayesian model averaging and inverse probability of treatment weighting-adjusted RFS analysis. Postoperative outcomes were comparable between groups, except for lower AST and ALT peak in the D-HOPE group.

CONCLUSIONS

In this single-center study, D-HOPE did not reduce HCC recurrence but allowed utilizing livers from extended criteria donors with comparable outcomes, improving access to LT for patients suffering from HCC.

Association between Hepatocellular Carcinoma Recurrence and Graft Size in Living Donor Liver Transplantation: A Systematic Review

The aim of this work was to assess the association between graft-to-recipient weight ratio (GRWR) in adult-to-adult living donor liver transplantation (LDLT) and hepatocellular carcinoma (HCC) recurrence. A search of the MEDLINE and EMBASE databases was performed until December 2022 for studies comparing different GRWRs in the prognosis of HCC recipients in LDLT. Data were pooled to evaluate 1- and 3-year survival rates. We identified three studies, including a total of 782 patients (168 GRWR < 0.8 vs. 614 GRWR ≥ 0.8%). The pooled overall survival was 85% and 77% at one year and 90% and 83% at three years for GRWR < 0.8 and GRWR ≥ 0.8, respectively. The largest series found that, in patients within Milan criteria, the GRWR was not associated with lower oncological outcomes. However, patients with HCC outside the Milan criteria with a GRWR < 0.8% had lower survival and higher tumor recurrence rates. The GRWR < 0.8% appears to be associated with lower survival rates in HCC recipients, particularly for candidates with tumors outside established HCC criteria. Although the data are scarce, the results of this study suggest that considering the individual GRWR not only as risk factor for small-for-size-syndrome but also as contributor to HCC recurrence in patients undergoing LDLT would be beneficial. Novel perfusion technologies and pharmacological interventions may contribute to improving outcomes.

Preservation of Mitochondrial Health in Liver Ischemia/Reperfusion Injury

Liver ischemia-reperfusion injury (LIRI) is a major cause of the development of complications in different clinical settings such as liver resection and liver transplantation. Damage arising from LIRI is a major risk factor for early graft rejection and is associated with higher morbidity and mortality after surgery. Although the mechanisms leading to the injury of parenchymal and non-parenchymal liver cells are not yet fully understood, mitochondrial dysfunction is recognized as a hallmark of LIRI that exacerbates cellular injury. Mitochondria play a major role in glucose metabolism, energy production, reactive oxygen species (ROS) signaling, calcium homeostasis and cell death. The diverse roles of mitochondria make it essential to preserve mitochondrial health in order to maintain cellular activity and liver integrity during liver ischemia/reperfusion (I/R). A growing body of studies suggest that protecting mitochondria by regulating mitochondrial biogenesis, fission/fusion and mitophagy during liver I/R ameliorates LIRI. Targeting mitochondria in conditions that exacerbate mitochondrial dysfunction, such as steatosis and aging, has been successful in decreasing their susceptibility to LIRI. Studying mitochondrial dysfunction will help understand the underlying mechanisms of cellular damage during LIRI which is important for the development of new therapeutic strategies aimed at improving patient outcomes. In this review, we highlight the progress made in recent years regarding the role of mitochondria in liver I/R and discuss the impact of liver conditions on LIRI.

Multiple Pretransplant Treatments for Patients Without Pathological Complete Response may Worsen Posttransplant Outcomes in Patients with Hepatocellular Carcinoma

BACKGROUND

Liver transplant (LT) candidates with hepatocellular carcinoma (HCC) often receive cancer treatment before transplant. We investigated the impact of pre-transplant treatment for HCC on the risk of posttransplant recurrence.

METHODS

Adult HCC patients with LT at our institution between 2013 and 2020 were included. The impact of pre-LT cancer treatments on the cumulative recurrence was evaluated, using the Gray and Fine-Gray methods adjusted for confounding factors. Outcomes were considered in two ways: 1) by pathologically complete response (pCR) status within patients received pre-LT treatment; and 2) within patients without pCR, grouped by pre-LT treatment as A) none; B) one treatment; C) multiple treatments.

RESULTS

The sample included 179 patients, of whom 151 (84%) received pretreatment and 42 (28% of treated) demonstrated pCR. Overall, 22 (12%) patients experienced recurrence. The 5-year cumulative post-LT recurrence rate was significantly lower in patients with pCR than those without pCR (4.8% vs. 19.2%, P = 0.03). In bivariable analyses, pCR significantly decreased risk of recurrence. Among the 137 patients without pCR (viable HCC in the explant), 28 (20%) had no pretreatment (A), 70 (52%) had one treatment (B), and 39 (20%) had multiple treatments (C). Patients in Group C had higher 5-year recurrence rates than those in A or B (39.6% vs. 8.2%, 6.5%, P = 0.004 and P < 0.001, respectively). In bivariable analyses, multiple treatments was significantly associated with recurrence.

CONCLUSIONS

pCR is a favorable prognostic factor after LT. When pCR was not achieved by pre-LT treatment, the number of treatments might be associated with post-LT oncological prognosis.

Postoperative Plasmacytoid Dendritic Cells Secrete IFNα to Promote Recruitment of Myeloid-Derived Suppressor Cells and Drive Hepatocellular Carcinoma Recurrence

Patients with hepatocellular carcinoma (HCC) confront a high incidence of tumor recurrence after curative surgical resection. Hepatic ischemia-reperfusion injury (IRI) is the major consequence of surgical stress during hepatectomy. Although it has been suggested that hepatic IRI-induced immunosuppression could contribute to tumor relapse after surgery, the underlying mechanisms have not been fully defined. Here, using a multiplex cytokine array, we found that levels of postoperative IFNα serve as an independent risk factor for tumor recurrence in 100 patients with HCC with curative hepatectomy. Plasmacytoid dendritic cells (pDC), the major source of IFNα, were activated after surgery and correlated with poor disease-free survival. Functionally, IFNα was responsible for mobilization of myeloid-derived suppressor cells (MDSC) following hepatic IRI. Conditioned medium from IFNα-treated hepatocytes mediated the migration of MDSCs in vitro. Mechanistically, IFNα upregulated IRF1 to promote hepatocyte expression of CX3CL1, which subsequently recruited CX3CR1+ monocytic MDSCs. Knockdown of Irf1 or Cx3cl1 in hepatocytes significantly inhibited the accumulation of monocytic MDSCs in vivo. Therapeutically, elimination of pDCs, IFNα, or CX3CR1 could restore the tumor-killing activity of CD8+ T cells, hence limiting tumor growth and lung metastasis following hepatic IRI. Taken together, these data suggest that IFNα-producing pDCs drive CX3CR1+ MDSC recruitment via hepatocyte IRF1/CX3CL1 signaling and lead to tumor recurrence after hepatectomy in HCC. Targeting pDCs and the IFNα/CX3CL1/CX3CR1 axis could inhibit surgical stress-induced HCC recurrence by attenuating postoperative immunosuppression.

SIGNIFICANCE

IFNα secreted by plasmacytoid dendritic cells drives postoperative immunosuppression and early recurrence of hepatocellular carcinoma, providing new biomarkers and therapeutic targets to improve patient outcomes after surgical resection.

SOCS5 knockdown suppresses metastasis of hepatocellular carcinoma by ameliorating HIF-1α-dependent mitochondrial damage

The Pringle maneuver (PM) is widely used during hepatocellular carcinoma (HCC) resection. However, it inevitably leads to ischemia and hypoxia, which promotes tumor metastasis. In this study, immunohistochemical staining of specimens from 130 HCC patients revealed that long-time PM significantly affected the prognosis of patients with high expression of suppressor of cytokine signaling 5 (SOCS5), but did not affect the prognosis of patients with low expression of SOCS5. The TCGA database showed that patients with high expression of SOCS5 had higher hypoxia scores, and it was proved that SOCS5 could promote the expression of hypoxia-inducible factor 1 subunit alpha (HIF-1α) protein by clinical tissue samples, cell experiments, lung metastases, and subcutaneous tumorigenesis experiments. Then, we used CoCl2 to construct a hypoxia model, and confirmed that SOCS5 knockdown resisted hypoxia-induced mitochondrial damage by inhibiting the expression of HIF-1α, thereby inhibiting the invasion and migration of HCC cells by immunofluorescence, electron microscopy, migration, invasion, and other experiments. We performed rescue experiments using LY294002 and rapamycin and confirmed that the knockdown of SOCS5-inhibited HCC cell invasion and migration by inhibiting the PI3K/Akt/mTOR/HIF-1α signaling axis. More importantly, we obtained consistent conclusions from clinical, cellular, and animal studies that the hypoxia-induced invasion and migration ability of SOCS5-inhibited HCC were weaker than that of normal HCC. In conclusion, we identified a novel role for SOCS5 in regulating HIF-1α-dependent mitochondrial damage and metastasis through the PI3K/Akt/mTOR pathway. The development of a SOCS5-specific inhibitor, an indirect inhibitor of HIF-1α, might be effective at controlling PM-induced tumor micrometastases during HCC resection.

Molecular Mechanisms of Ischaemia-Reperfusion Injury and Regeneration in the Liver-Shock and Surgery-Associated Changes

Hepatic ischemia-reperfusion injury (IRI) represents a major challenge during liver surgery, liver preservation for transplantation, and can cause hemorrhagic shock with severe hypoxemia and trauma. The reduction of blood supply with a concomitant deficit in oxygen delivery initiates various molecular mechanisms involving the innate and adaptive immune response, alterations in gene transcription, induction of cell death programs, and changes in metabolic state and vascular function. Hepatic IRI is a major cause of morbidity and mortality, and is associated with an increased risk for tumor growth and recurrence after oncologic surgery for primary and secondary hepatobiliary malignancies. Therapeutic strategies to prevent or treat hepatic IRI have been investigated in animal models but, for the most part, have failed to provide a protective effect in a clinical setting. This review focuses on the molecular mechanisms underlying hepatic IRI and regeneration, as well as its clinical implications. A better understanding of this complex and highly dynamic process may allow for the development of innovative therapeutic approaches and optimize patient outcomes.

Mitochondria and Cancer Recurrence after Liver Transplantation—What Is the Benefit of Machine Perfusion?

Tumor recurrence after liver transplantation has been linked to multiple factors, including the recipient’s tumor burden, donor factors, and ischemia-reperfusion injury (IRI). The increasing number of livers accepted from extended criteria donors has forced the transplant community to push the development of dynamic perfusion strategies. The reason behind this progress is the urgent need to reduce the clinical consequences of IRI. Two concepts appear most beneficial and include either the avoidance of ischemia, e.g., the replacement of cold storage by machine perfusion, or secondly, an endischemic organ improvement through perfusion in the recipient center prior to implantation. While several concepts, including normothermic perfusion, were found to reduce recipient transaminase levels and early allograft dysfunction, hypothermic oxygenated perfusion also reduced IRI-associated post-transplant complications and costs. With the impact on mitochondrial injury and subsequent less IRI-inflammation, this endischemic perfusion was also found to reduce the recurrence of hepatocellular carcinoma after liver transplantation. Firstly, this article highlights the contributing factors to tumor recurrence, including the surgical and medical tissue trauma and underlying mechanisms of IRI-associated inflammation. Secondly, it focuses on the role of mitochondria and associated interventions to reduce cancer recurrence. Finally, the role of machine perfusion technology as a delivery tool and as an individual treatment is discussed together with the currently available clinical studies.

One Shoot, Two Birds: Alleviating Inflammation Caused by Ischemia/Reperfusion Injury to Reduce the Recurrence of Hepatocellular Carcinoma

Inflammation is crucial to tumorigenesis and the development of metastasis. Hepatic ischemia/reperfusion injury (IRI) is an unresolved problem in liver resection and transplantation which often establishes and remodels the inflammatory microenvironment in liver. More and more experimental and clinical evidence unmasks the role of hepatic IRI and associated inflammation in promoting the recurrence of hepatocellular carcinoma (HCC). Meanwhile, approaches aimed at alleviating hepatic IRI, such as machine perfusion, regulating the gut-liver axis, and targeting key inflammatory components, have been proved to prevent HCC recurrence. This review article highlights the underlying mechanisms and promising therapeutic strategies to reduce tumor recurrence through alleviating inflammation induced by hepatic IRI.

The effect of the number of hepatic inflow occlusion times on the prognosis of ruptured hepatocellular carcinoma patients after hepatectomy

Background and aim

It has been previously reported that inflow occlusion does not affect postoperative outcomes in hepatocellular carcinoma patients. However, for patients with ruptured hepatocellular carcinoma(rHCC), the effect of hepatic inflow occlusion and the number of occlusion times on the prognosis is unknown.

Methods

203 patients with ruptured hepatocellular carcinoma were enrolled in this study. They were first divided into the non-hepatic inflow occlusion (non-HIO) group and the hepatic inflow occlusion (HIO) group. The Kaplan–Meier method was used to compare the recurrence-free survival and overall survival between the two groups. Patients in the HIO group were further divided into one-time HIO and two times HIO groups. KM method was also used to compare the two groups. Finally, independent risk factors affecting RFS and OS were determined by multivariate Cox regression analysis.

Result

In the non-HIO group, 1-,3- and 5-year OS rates were 67.0%, 41.0%, and 22.0%respectively, and RFS rates were 45.0%, 31.0%, and 20.0% respectively; In the one-HIO group, the 1-,3-, and 5-year OS rates were 55.1%, 32.1%, and 19.2% respectively, and RFS rates were 33.3%, 16.7%, and 7.7% respectively; In the two-HIO group, 1-,3-, and 5-year OS rates were 24.0%, 0.0%, and 0.0% respectively, and RFS rates were 8.0%, 0.0%, and 0.0% respectively. By Cox regression analysis, HIO was an independent risk factor for a poor prognosis in rHCC patients.

Conclusion

One time hepatic inflow occlusion did not affect postoperative OS, but negatively affected the RFS of rHCC patients; two times hepatic inflow occlusion negatively affected the postoperative OS and RFS in patients with rHCC.

Ischemic-Free Liver Transplantation Reduces the Recurrence of Hepatocellular Carcinoma After Liver Transplantation

Ischemia reperfusion injury (IRI) is an adverse factor for hepatocellular carcinoma (HCC) recurrence after liver transplantation. Ischemic-free liver transplantation (IFLT) is a novel transplant procedure that can largely reduce or even prevent IRI, but the clinical relevance of IFLT and the recurrence of HCC after liver transplantation are still unknown. This retrospective study compared survival outcomes, HCC recurrence, perioperative data and IRI severity following liver transplantation (LT). 30 patients received IFLT and 196 patients received conventional liver transplantation (CLT) were chosen for the entire cohort between June 2017 and August 2020. A 1:3 propensity score matching was performed, 30 IFLT recipients and 85 matched CLT patients were enrolled in propensity-matched cohorts. An univariate and multivariate Cox regression analysis was performed, and showed surgical procedure (CLT vs IFLT) was an independent prognostic factor (HR 3.728, 95% CI 1.172-11.861, P=0.026) for recurrence free survival (RFS) in HCC patients following liver transplantation. In the Kaplan–Meier analysis, the RFS rates at 1 and 3 years after LT in recipients with HCC in the IFLT group were significantly higher than those in the CLT group both in the entire cohort and propensity-matched cohort (P=0.006 and P=0.048, respectively). In addition, patients in the IFLT group had a lower serum lactate level, lower serum ALT level and serum AST level on postoperative Day 1. LT recipients with HCC in the IFLT group had a lower incidence of early allograft dysfunction than LT recipients with HCC in the CLT group. Histological analysis showed no obvious hepatocyte necrosis or apoptosis in IFLT group. In conclusion, IFLT can significantly reduce IRI damage and has the potential to be a useful strategy to reduce HCC recurrence after liver transplantation.

A case of primary aortic sarcoma with tumor infarction after stent graft placement

Primary aortic sarcoma is a very rare disease, and most primary aortic tumors are malignant mesenchymal tumors. We present the case of a 62-year-old man with sudden epigastric and back pain. Contrast-enhanced computed tomography (CT) revealed a mass lesion about 33.8 mm in diameter, in contact with the left side of the abdominal aorta. Impending rupture of an abdominal aortic aneurysm was suspected, so cardiovascular surgery for stent graft placement was performed the same day. Symptoms immediately improved and CT at 3 months postoperatively showed a marked decrease in lesion size, but the lesion subsequently grew again. Fluorodeoxyglucose (FDG)-positron emission tomography/CT was performed due to the possibility of malignant solid tumor, revealing markedly increased FDG accumulation (maximum standardized uptake value, 36.95) in the mass lesion. Primary aortic sarcoma was diagnosed from thoracoscopic biopsy. Here, we report a primary aortic sarcoma that shrank due to tumor infarction after stent graft placement, followed by tumor regrowth.

Predicting recurrence of hepatocellular carcinoma after liver transplantation using a novel model that incorporates tumor and donor-related factors

Evidence suggests that liver graft quality impacts on posttransplant recurrence of hepatocellular carcinoma (HCC). As of today, selection criteria only use variables related to tumor characteristics. Within the Scientific Registry of Transplant Recipients, we identified patients with HCC who underwent liver transplantation between 2004 and 2016 (development cohort, n = 10 887). Based on tumor recurrence rates, we fitted a competing-risk regression incorporating tumor- and donor-related factors, and we developed a prognostic score. Results were validated both internally and externally in the Australia and New Zealand Liver Transplant Registry. Total tumor diameter (subhazard ratio [sub-HR] 1.52 [1.28-1.81]), alpha-feto protein (sub-HR 1.27 [1.23-1.32], recipient male gender (sub-HR 1.43 [1.18-1.74]), elevated donor body mass index (sub-HR 1.26 [1.01-1.58]), and shared graft allocation policy (sub-HR 1.20 [1.01-1.43]) were independently associated with tumor recurrence. We next developed the Darlica score (sub-HR 2.72 [2.41-3.08] P < 0.001) that allows identifying risky combinations between a given donor and a given recipient. Results were validated internally (n = 3 629) and externally in the Australia and New Zealand Liver Transplant Registry (n = 370). The current score is based on variables that are readily available at the time of graft offer. It allows identifying hazardous donor-recipient combinations in terms of risk of tumor recurrence and overall survival.

New Insights in Mechanisms and Therapeutics for Short- and Long-Term Impacts of Hepatic Ischemia Reperfusion Injury Post Liver Transplantation

Liver transplantation has been identified as the most effective treatment for patients with end-stage liver diseases. However, hepatic ischemia reperfusion injury (IRI) is associated with poor graft function and poses a risk of adverse clinical outcomes post transplantation. Cell death, including apoptosis, necrosis, ferroptosis and pyroptosis, is induced during the acute phase of liver IRI. The release of danger-associated molecular patterns (DAPMs) and mitochondrial dysfunction resulting from the disturbance of metabolic homeostasis initiates graft inflammation. The inflammation in the short term exacerbates hepatic damage, leading to graft dysfunction and a higher incidence of acute rejection. The subsequent changes in the graft immune environment due to hepatic IRI may result in chronic rejection, cancer recurrence and fibrogenesis in the long term. In this review, we mainly focus on new mechanisms of inflammation initiated by immune activation related to metabolic alteration in the short term during liver IRI. The latest mechanisms of cancer recurrence and fibrogenesis due to the long-term impact of inflammation in hepatic IRI is also discussed. Furthermore, the development of therapeutic strategies, including ischemia preconditioning, pharmacological inhibitors and machine perfusion, for both attenuating acute inflammatory injury and preventing late-phase disease recurrence, will be summarized in the context of clinical, translational and basic research.

Glutathione S-transferase A2 promotes hepatocellular carcinoma recurrence after liver transplantation through modulating reactive oxygen species metabolism

Hepatocellular carcinoma (HCC) recurrence after liver transplantation remains a significant clinical problem. Ischemia-reperfusion injury (IRI) occurred inevitably at the early phase after liver transplantation (LT) spawns a significant risk of HCC recurrence. However, their linkage and IRI-derived risk factors for HCC recurrence remain exclusive. Understanding the mechanism of post-transplantation hepatic injury could provide new strategies to prevent the later event of HCC recurrence. We demonstrated that glutathione S-transferase A2 (GSTA2) expression was significantly associated with early phase hepatic and systemic injury and ROS level after liver transplantation. Early phase circulating GSTA2 (_EPCGSTA2) protein was a significant predictor of HCC recurrence and survival. Heterogeneous single nucleotide polymorphism at G335C of GSTA2 was significantly associated with poor survival of HCC recipients. Enhancement of GSTA2 could protect HCC cells against H₂O₂-induced cell death by compensating for the elevated ROS stress. We also demonstrated that GSTA2 played crucial roles in regulating the ROS-associated JNK and AKT signaling pathways and ROS metabolism in HCCs in responding to a dynamic ROS environment. Functionally, endogenous or exogenous upregulation of GSTA2 could promote HCC growth and invasion through activating the epithelial–mesenchymal-transition process. Targeted inhibition of GSTA2 could suppress HCC growth and metastasis. In conclusion, GSTA2 could be a novel prognostic and therapeutic target to combat HCC recurrence after liver transplantation.

Left Hepatectomy Through Double Approach and Total Vascular Exclusion for Giant Left Lobe Hepatocarcinoma

BACKGROUND/AIM

Hepatocellular carcinoma represents the most frequently encountered liver malignancy worldwide; however the dimensions of these lesions rarely surpass 20 cm. In such cases surgical treatment might encounter significant technical difficulties.

CASE REPORT

We present the case of a 49-year-old patient diagnosed with a 22/25/21 cm left lobe hepatocellular carcinoma.

RESULTS

In order to achieve a safe and effective resection total vascular exclusion was needed. Moreover, due to the anatomical relationship between the tumor and the cava vein, an intrathoracic approach of the inferior cava vein was the option of choice. The time of total vascular exclusion was of 26 minutes while the length of surgery was of 210 minutes; meanwhile the estimated blood loss was of 650 ml, while the postoperative outcome was uncomplicated.

CONCLUSION

Total vascular exclusion by double approach might be a safe alternative in order to minimize the risks of severe intraoperative and postoperative complications.

Preventing Tumour Recurrence after Liver Transplantation: The Role of Machine Perfusion

Tumour recurrence is currently a hot topic in liver transplantation. The basic mechanisms are increasingly discussed, and, for example, recurrence of hepatocellular carcinoma is often described in pre-injured donor livers, which frequently suffer from significant ischemia/reperfusion injury. This review article highlights the underlying mechanisms and describes the specific tissue milieu required to promote tumour recurrence after liver transplantation. We summarise the current literature in this field and show risk factors that contribute to a pro-tumour-recurrent environment. Finally, the potential role of new machine perfusion technology is discussed, including the most recent data, which demonstrate a protective effect of hypothermic oxygenated perfusion before liver transplantation.

Does vascular occlusion in liver resections predispose to recurrence of malignancy in the liver remnant due to ischemia/reperfusion injury? A comparative retrospective cohort study

BACKGROUND

Severe ischemic changes of the liver remnant after hepatectomy could expedite tumor recurrence on the residual liver. Our study aimed at assessing the effect of warm ischemic/reperfusion (I/R) injuries on surgery-to-local recurrence interval and patient overall survival, during major hepatectomies under inflow and outflow vascular control.

METHODS

One hundred and eighteen patients were subjected to liver resection under total inflow and outflow vascular clamping and were assigned as study group. These individuals were retrospectively matched to 112 counterparts, who underwent liver surgery applying inflow and outflow vascular clamping only of the segment harboring the tumor, sparing the liver remnant from any I/R injury (control group). The two cohorts were compared regarding recurrence-free survival and overall survival.

RESULTS

Reversible I/R injuries of the liver remnant subjected to vascular clamping were manifested, with increase of AST values at postoperative day 2 in the study group, as compared to the control group (603 ± 270 U/L vs. 450 ± 290 U/L, p < 0.001), reversing to normal by day 7. Recurrence-free survival and overall survival were no significantly different between the two groups (log rank statistic p = 0.298 and 0.639, respectively).

CONCLUSION

Reversible I/R injuries of the liver remnant do not seem to be implicated in the precipitation of local malignant recurrence or in shorter long-term survival, in comparison to a technique sparing the residual liver of I/R injury. This retrospective cohort study was registered at clinicaltrials.gov under unique identifying number: NCT04257240.

Does graft hemodynamics affect the risk of hepatocellular carcinoma recurrence after liver transplantation?

Although experimental studies have reported that hepatic ischemia-reperfusion injury promotes tumor growth and metastases, the impact of graft hemodynamics on the recurrence of hepatocellular carcinoma (HCC) after liver transplantation (LT) is unclear. To investigate the association between graft hemodynamics and HCC recurrence after LT, we conducted a retrospective analysis of 279 patients who underwent LT for HCC. Graft hemodynamics including portal vein flow (PVF), hepatic artery flow (HAF), and total hepatic flow (THF) was analyzed as a predictor of HCC recurrence, using competing risk regression analyses. The cutoff values of PVF, HAF, and THF were set at the lower quartile of distribution. A cumulative recurrence curve demonstrated that low THF (<1511 mL/min, P = .005) was significantly associated with increased recurrence, whereas neither low PVF (<1230 mL/min, P = .150) nor low HAF (<164 mL/min, P = .110) was significant. On multivariate analysis, outside Milan criteria (sub-hazard ratio [SHR] = 3.742; P < .001), microvascular invasion (SHR = 3.698; P < .001), and low THF (SHR = 2.359; P = .010) were independently associated with increased HCC recurrence. In conclusion, our findings suggest that graft hemodynamics may play an important role in HCC recurrence after LT.

IL-17a exacerbates hepatic ischemia-reperfusion injury in fatty liver by promoting neutrophil infiltration and mitochondria-driven apoptosis

Hepatic ischemia-reperfusion (IR) injury is a critical issue during liver transplantation (LT). Recent studies have demonstrated that IL-17a contributes to IR injury and steatohepatitis. However, the underlying mechanism is not understood. This study aimed to examine the role of IL-17a on hepatic IR injury in fatty liver and to investigate the underlying mechanisms. The correlation between serum IL-17a levels and liver function was analyzed in LT patients receiving fatty (n = 42) and normal grafts (n = 44). Rat LT model was applied to validate the clinical findings. IL-17a knockout (KO) and wild-type mice were fed with high-fat diets to induce fatty liver and subjected to hepatic IR injury with major hepatectomy. Frequency of circulating neutrophils and IL-17a expression on PBMCs were analyzed by flow cytometry. Mitochondrial outer membrane permeabilization (MOMP) was examined by a living intravital image system. Serum IL-17a was elevated after human LT, especially with fatty grafts. The aspartate aminotransferase and alanine transaminase levels were increased in recipients with fatty grafts compared with normal grafts. In rat LT model, the intragraft IL-17a expression was significantly higher in fatty grafts than normal ones post-LT. KO of IL-17a in mice notably attenuated liver damage after IR injury in fatty liver, characterized by better-preserved liver architecture, improved liver function, and reduced neutrophil infiltration. MOMP triggered cell death after hepatic IR injury in a caspase-independent way via IL-17a/NF-κB signaling pathway. KO of IL-17a protected the fatty liver against IR injury through the suppression of neutrophil infiltration and mitochondria-driven apoptosis.

FTY720 Suppresses Liver Tumor Growth and Metastasis by Reducing Circulating Regulating T Cells and Enhancing the Anti-Tumor Effect of Rapamycin

Background

In this study, we aimed to study the effect of FTY720 treatment in reducing circulating Tregs level and then suppressing liver tumor metastasis after hepatectomy and I/R injury in animal models. Furthermore, we also investigated the synergistic anti-tumor effect of FTY720 combined with rapamycin on hepatocellular carcinoma.

Methods

The effect of FTY720 on suppressing Tregs mobilization and tumor metastasis after hepatectomy was investigated in an orthotopic liver tumor rat model with hepatectomy and hepatic ischemia/reperfusion (I/R) injury. The synergistic anti-tumor effect of FTY720 combined with rapamycin was further explored both in in vitro functional study and in orthotopic liver tumor mouse model.

Results

In rat model, hepatic I/R promoted tumor metastasis and increased circulating Tregs after hepatectomy. The treatment of FTY720 reduced liver tumor metastasis and the number of circulating Tregs. Furthermore, FTY720 enhanced the anti-tumor capacity of rapamycin by inhibiting tumor cell proliferation and migration in vitro and reducing tumor growth in vivo through suppressing hepatic stellate cell activation and tumor angiogenesis.

Conclusion

FTY720 suppressed liver tumor growth and metastasis by reducing the population of circulating Tregs and enhancing the anti-tumor effect of rapamycin. It was suggested that FTY720 single or combined with rapamycin might provide novel insight for suppressing tumor growth and metastasis for HCC patients.

Does the intermittent Pringle maneuver affect the recurrence following surgical resection for hepatocellular carcinoma? A systematic review

BACKGROUND AND AIM

To evaluate the effect of intermittent pringle maneuver (IPM) on the long-term prognosis and recurrence of hepatocellular carcinoma (HCC).

METHODS

Eligible studies were identified by PubMed and other databases from Jan 1st 1990 to Mar 31st 2019. Hazard ratios (HR) with 95% confidence interval (CI) were calculated to evaluate the effects of IPM on the long-term prognosis and recurrence of patients with HCC.

RESULTS

Six studies were enrolled in this meta-analysis. Results showed that there were no differences between IPM group and non-IPM group in the pooled HRs for the overall survival (OS) and disease-free survival (DFS) (HR 1.04, 95%CI 0.84~1.28, P = 0.74; HR 0.93, 95%CI 0.81~1.07, P = 0.29; respectively). However, subgroup analysis showed that the pooled Odd ratios (OR) for the 1-year OS and DFS rates of the IPM group when compared with the non-IPM group were 0.65 (95% CI 0.45~0.94, P = 0.02), 0.38 (95% CI 0.20~0.72, P = 0.003), respectively. In addition, there were no significant differences in the proportions of liver cirrhosis, HBsAg (+), Child-Pugh A class, multiple tumor, vascular invasion, and major hepatectomy between groups of IPM and non-IPM.

CONCLUSION

Since IPM would increase the risk of early-recurrence, it should be used cautiously in the procedure of hepatectomy for resectable HCC. However, the current conclusion needs further validation.

TRIAL REGISTRY NUMBER

CRD 42019124923.

Circulating exosomal miR-92b: Its role for cancer immunoediting and clinical value for prediction of posttransplant hepatocellular carcinoma recurrence

A recurrence of hepatocellular carcinoma (HCC) after living donor liver transplantation (LDLT) is one of the major concerns reflecting the higher mortality of HCC. This study aimed to explore the impact of circulating exosomes on HCC development and recurrence. One-shot transfusion of hepatoma serum to naïve rats induced liver cancer development with gradual elevation of alpha-fetoprotein (AFP), but exosome-free hepatoma serum failed to induce AFP elevation. The microarray analysis revealed miR-92b as one of the highly expressing microribonucleic acids in hepatoma serum exosomes. Overexpression of miR-92b enhanced the migration ability of liver cancer cell lines with active release of exosomal miR-92b. The hepatoma-derived exosomal miR-92b transferred to natural killer (NK) cells, resulting in the downregulation of CD69 and NK cell-mediated cytotoxicity. Furthermore, higher expression of miR-92b in serum exosomes was confirmed in HCC patients before LDLT, and its value at 1 month after LDLT was maintained at a higher level in the patients with posttransplant HCC recurrence. In summary, we demonstrated the impact of circulating exosomes on liver cancer development, partly through the suppression of CD69 on NK cells by hepatoma-derived exosomal miR-92b. The value of circulating exosomal miR-92b may predict the risk of posttransplant HCC recurrence.

Obtaining Optimal Long-Term Outcomes from Liver Transplantation for Hepatocellular Cancer

Liver transplantation is the definitive treatment for patients with end-stage liver disease. Liver transplantation is also the optimal treatment for patients with hepatocellular carcinoma (HCC), especially in the setting of chronic liver disease. Unfortunately, due to the worldwide shortage of organs, this treatment is not available for all patients with HCC. Strict selection criteria have been developed in order to obtain optimal results. A surgical perspective of the preoperative selection, perioperative management, and postoperative care of patients is reviewed in depth and provides an overview for obtaining optimal long-term results from liver transplantation for HCC. With rigorous selection and patient management, excellent long-term outcomes can be obtained with liver transplantation for patients with HCC.

Does Intermittent Pringle Maneuver Increase Postoperative Complications After Hepatectomy for Hepatocellular Carcinoma? A Randomized Controlled Trial

BACKGROUND

In a previous study, we have shown that intermittent Pringle maneuver (IPM) might increase postoperative complications after hepatectomy for various indications. Complications which thought to be related to IPM were ascites, pleural effusion, wound infection and intra-abdominal collection. The aim of this study was to test the hypothesis that applying IPM during hepatectomy for hepatocellular carcinoma (HCC) could increase postoperative complications.

METHODS

Between January 2013 and October 2016, eligible patients who received elective open hepatectomy for HCC were randomized to have IPM or no Pringle maneuver (NPM). Occurrence of various types of postoperative complications was specifically looked for. A routine postoperative day 5 abdominal ultrasound examination and chest X-ray were done to detect and grade any radiological ascites, pleural effusion and intra-abdominal collection.

RESULTS

Fifty IPM and 50 NPM patients with histological proven HCC were recruited for final analysis. Demographics and operative parameters were comparable between the two groups. The postoperative complication rates were similar (IPM 36.0 vs. NPM 28.0%, P = 0.391). However, in the IPM group, more patients developed radiological posthepatectomy ascites (42.0 vs. 22.0%, P = 0.032) and pleural effusion (66.0 vs. 38.0%, P = 0.005). In patients with histologically proven cirrhosis, there were 28 IPM and 25 NPM patients. Again, there was no difference in postoperative complication rate but more radiological posthepatectomy ascites and pleural effusion in the IPM group.

CONCLUSION

This trial was not able to detect a difference in postoperative complications whether IPM was applied or not, but use of IPM was associated with more subclinical ascites and pleural effusion. (ClinicalTrials.gov NCT01759901).

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov NCT01759901.

Ischemia-reperfusion injury and the risk of hepatocellular carcinoma recurrence after deceased donor liver transplantation

This study aimed to evaluate the effects of ischemia-reperfusion injury (IRI) on the risk of hepatocellular carcinoma (HCC) recurrence after liver transplantation. Data of 195 patients were retrospectively analysed. Post-reperfusion aspartate (AST), alanine transaminase, and lactate dehydrogenase (LDH) levels were the primary measures of IRI. Tumour recurrence was the primary endpoint. Post-reperfusion AST was a continuous risk factor for tumour recurrence in patients within Milan criteria (p = 0.035), with an optimal cut-off of 1896 U/L. Recurrence-free survival of patients within Milan criteria and post-reperfusion AST of <1896 and ≥1896 U/L was 96.6% and 71.9% at 5 and 3.7 years, respectively (p = 0.006). Additionally, post-reperfusion AST and LDH exceeding the upper quartile significantly increased the risk of HCC recurrence in patients within Milan criteria (p = 0.039, hazard ratio [HR] = 5.99 and p = 0.040, HR = 6.08, respectively) and to a lesser extent, in patients within Up-to-7 criteria (p = 0.028, HR = 3.58 and p = 0.039, HR = 3.33, respectively). No other significant IRI effects were found in patients beyond the Up-to-7 criteria and in analyses stratified for independent risk factors for recurrence: tumour number and differentiation, alpha-fetoprotein, and microvascular invasion. Thus, IRI exerts major negative effects on the risk of HCC recurrence after liver transplantation in patients within standard and extended criteria.

Effects of the gut-liver axis on ischaemia-mediated hepatocellular carcinoma recurrence in the mouse liver

BACKGROUND & AIMS

There is growing evidence that liver graft ischemia-reperfusion (I/R) is a risk factor for hepatocellular carcinoma (HCC) recurrence, but the mechanisms involved are unclear. Herein, we tested the hypothesis that mesenteric congestion resulting from portal blood flow interruption induces endotoxin-mediated Toll-like receptor 4 (Tlr4) engagement, resulting in elevated liver cancer burden. We also assessed the role of remote ischemic preconditioning (RIPC) in this context.

METHODS

C57Bl/6j mice were exposed to standardized models of liver I/R injury and RIPC, induced by occluding the hepatic and femoral blood vessels. HCC was induced by injecting RIL-175 cells into the portal vein. We further evaluated the impact of the gut-liver axis (lipopolysaccharide (LPS)-Tlr4 pathway) in this context by studying mice with enhanced (lipopolysaccharide infusion) or defective (Tlr4^-/- mice, gut sterilization, and Tlr4 antagonist) Tlr4 responses.

RESULTS

Portal triad clamping provoked upstream mesenteric venous engorgement and increased bacterial translocation, resulting in aggravated tumor burden. RIPC prevented this mechanism by preserving intestinal integrity and reducing bacterial translocation, thereby mitigating HCC recurrence. These observations were linked to the LPS-Tlr4 pathway, as supported by the high and low tumor burden displayed by mice with enhanced or defective Tlr4 responses, respectively.

CONCLUSIONS

Modulation of the gut-liver axis and the LPS-Tlr4 response by RIPC, gut sterilization, and Tlr4 antagonism represents a potential therapeutic target to prevent I/R lesions, and to alleviate HCC recurrence after liver transplantation and resection.

LAY SUMMARY

Cancer recurrence can occur after liver resection or liver transplantation for hepatocellular carcinoma (HCC). This study suggests that intestinal venous congestion, which often occurs during liver surgery, favors the translocation of gut-derived bacterial products in the portal vein, thereby facilitating cancer recurrence by enhancing the signaling of Toll-like receptor 4 in the liver. Using a mouse model of HCC recurrence, we show that strategies that (i) reduce bacterial translocation (by gut decontamination, or by protecting the intestine from venous ischemia damage) or (ii) inhibit Tlr4 signaling in the liver, could reduce cancer recurrence.

CAAT/enhancer binding protein-homologous protein deficiency attenuates liver ischemia/reperfusion injury in mice

Ischemia/reperfusion injury (IRI) is one of the main causes of liver dysfunction after liver surgery. Involvement of endoplasmic reticulum (ER) stress in various diseases has been demonstrated, and CAAT/enhancer binding protein-homologous protein (CHOP) is a transcriptional regulator that is induced by ER stress. It is also a key regulator of ER stress-mediated apoptosis. The aim of this study was to investigate the role of CHOP in liver IRI. Wild type (WT) and CAAT/enhancer binding protein-homologous protein knockout (CHOP-/-) mice were subjected to 70% liver warm ischemia/reperfusion for 60 minutes. At different times after reperfusion, liver tissues and blood samples were collected for evaluation. Induction of ER stress including CHOP expression was ascertained. Liver damage was evaluated based on serum liver enzymes, liver histology, and neutrophil infiltration. Hepatocyte death including apoptosis was assessed. Liver warm IRI induced ER stress in both WT and CHOP-/- mice. In addition, CHOP expression was up-regulated in WT mice. At 6 hours after reperfusion, liver damage was attenuated in CHOP-/- mice. On the basis of terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling staining, apoptotic and necrotic cells were significantly reduced in CHOP-/- mice. CHOP deficiency also reduced the cleavage of caspase 3 and expression of the proapoptotic protein B cell lymphoma 2-associated X protein. Liver IRI induces CHOP expression, and CHOP deficiency attenuates liver IRI by inhibiting apoptosis. Elucidation of the function of CHOP in liver IRI may contribute to further investigation for a therapy against liver IRI associated with the ER stress pathway. Liver Transplantation 24 645-654 2018 AASLD.

Small-for-size grafts increase recurrence of hepatocellular carcinoma in liver transplantation beyond milan criteria

Living donor liver transplantation (LDLT) has been reported to have high rates of hepatocellular carcinoma (HCC) recurrence compared with deceased donor liver transplantation (DDLT). This has been assumed to be due to the frequent use of small-for-size grafts (SFSGs) in LDLT rather than DDLT, but the relationship between graft size and prognosis remains controversial. This study aimed to clarify the effect of SFSGs on the oncologic outcomes of patients with HCC who underwent LDLT. Between January 2005 and December 2015, 597 consecutive patients underwent LDLT. Among these patients, those with HCC who underwent LDLT were randomly matched at a 1:3 ratio (graft-to-recipient body weight ratio [GRWR] < 0.8%:GRWR > 0.8%) according to propensity score. HCC recurrence and patient survival were analyzed using the Kaplan-Meier method and log-rank test. In addition, stratified subgroup analysis based on the Milan criteria was performed. SFSG was defined as a GRWR < 0.8%. Using propensity score matching, 82 patients with GRWR < 0.8% and 246 patients with GRWR ≥ 0.8% were selected. For patients with HCC within the Milan criteria, no significant difference of HCC recurrence (P = 0.82) and patient survival (P = 0.95) was found based on GRWR. However, for patients with HCC beyond the Milan criteria, 1-, 3-, and 5-year recurrence-free survival rates were 52.4%, 49.3%, and 49.3%, respectively, for patients with GRWR < 0.8%, and 76.5%, 68.3%, and 64.3%, respectively, for patients with GRWR ≥ 0.8% (P = 0.049). The former group exhibited poor patient survival rates (P = 0.047). In conclusion, for patients with HCC within the Milan criteria, no significant difference in oncologic outcomes was found based on liver graft size. However, among the patients with HCC beyond the Milan criteria, SFSG recipients showed poor oncologic outcomes. Because extended criteria are frequently used in LDLT for HCC, a recipient's prognosis can be improved if a liver graft of appropriate size is carefully selected during donor selection. Liver Transplantation 24 35-43 2018 AASLD.

Proper hepatic pedicle clamping during hepatectomy is associated with improved postoperative long-term prognosis in patients with AJCC stage IIIB hepatocellular carcinoma

Intermittent hepatic pedicle clamping (HPC) is often performed during hepatectomy. Whether it affects the long-term prognosis of hepatocellular carcinoma (HCC) patients is still controversial. This study evaluated the impact of HPC in patients with different stages of HCC. The study included 1401 patients who underwent hepatectomy in the primary cohort with 129 AJCC stage IIIB HCC patients; there were 80 AJCC stage IIIB HCC patients in the validation cohort. In each cohort, patients were placed in the long-term HPC (LTHPC) group or the short-term HPC (STHPC) group based on the cut-off time of HPC estimated by the receiver-operating characteristic (ROC) curve. Although HPC did not show significant effects on the prognosis of stage I–IIIA HCC patients in the primary cohort, 1−, 3−, and 5-year overall survival (OS) and recurrence-free survival (RFS) rates of stage IIIB HCC patients who received LTHPC (HPC time > 12 minutes) were significantly higher than those with STHPC (HPC time ≤ 12 minutes or received no HPC), similar in the validation cohort. Multivariate analysis demonstrated HPC time was an independent protective factor for RFS and OS in stage IIIB HCC patients. Herein, we report that proper HPC improved the postoperative prognosis of stage IIIB HCC patients and served as an independent protective factor.

Repressor and activator protein accelerates hepatic ischemia reperfusion injury by promoting neutrophil inflammatory response

Repressor and activator protein (Rap1) directly regulates nuclear factor-κB (NF-κB) dependent signaling, which contributes to hepatic IRI. We here intended to investigate the effect of Rap1 in hepatic ischemia reperfusion injury (IRI) and to explore the underlying mechanisms. The association of Rap1 expression with hepatic inflammatory response were investigated in both human and rat liver transplantation. The effect of Rap1 in hepatic IRI was studied in Rap1 knockout mice IRI model in vivo and primary cells in vitro. Our results showed that over expression of Rap1 was associated with severe liver graft inflammatory response, especially in living donor liver transplantation. The results were also validated in rat liver transplantation model. In mice hepatic IRI model, the knockout of Rap1 reduced hepatic damage and hepatic inflammatory response. In primary cells, the knockout of Rap1 suppressed neutrophils migration activity and adhesion in response to liver sinusoidal endothelial cells through down-regulating neutrophils F-Actin expression and CXCL2/CXCR2 pathway. In addition, the knockout of Rap1 also decreased production of pro-inflammatory cytokines/chemokines in primary neutrophils and neutrophils-induced hepatocyte damage. In conclusion, Rap1 may induce hepatic IRI through promoting neutrophils inflammatory response. Rap1 may be the potential therapeutic target of attenuating hepatic IRI.

Early-phase circulating miRNAs predict tumor recurrence and survival of hepatocellular carcinoma patients after liver transplantation

Post-liver transplantation tumor recurrence is a major challenge for hepatocellular carcinoma (HCC) recipients. We aimed to identify early-phase circulating microRNAs after liver transplantation for predicting tumor recurrence and survival of HCC recipients. Circulating microRNA profiles at early-phase (2-hour after portal vein reperfusion) after liver transplantation were compared between HCC recipients with (n=4) and without tumor recurrence (n=8) by microarray analyses. Candidate microRNAs were validated in 62 HCC recipients by quantitative RT-PCR. The prognostic values of microRNAs for tumor recurrence and survival were examined. Simulated in vitro ischemia-reperfusion injury models were employed to characterize the possible mechanism of up-regulation of circulating microRNAs. Our results showed that up-regulation of circulating miR-148a, miR-1246 or miR-1290 at early-phase was significantly associated with HCC recurrence after liver transplantation. Among them, miR-148a (p=0.030) and miR-1246 (p=0.009) were significant predictors of HCC recurrence. MiR-1246 was an independent predictor of overall (p=0.023) and disease-free survival (p=0.020) of HCC recipients. The level of early-phase circulating miR-1246 was positively correlated with serum AST and ALT levels in HCC recipients after liver transplantation. The expression of hepatic miR-1246 was positively correlated with TNFα mRNA. In vitro experiments indicated that injury-induced activation and differentiation of macrophages significantly elevated the expression and secretion of miR-1246. In conclusion, early-phase circulating miR-1246 is an indicator of hepatic injury and a novel prognostic biomarker for tumor recurrence and survival of HCC recipients after liver transplantation.

The Impact of Liver Graft Injury on Cancer Recurrence Posttransplantation

Liver transplantation is the most effective treatment for selected patients with hepatocellular carcinoma. However, cancer recurrence, posttransplantation, remains to be the critical issue that affects the long-term outcome of hepatocellular carcinoma recipients. In addition to tumor biology itself, increasing evidence demonstrates that acute-phase liver graft injury is a result of hepatic ischemia reperfusion injury (which is an inevitable consequence during liver transplantation) and may promote cancer recurrence at late phase posttransplantation. The liver grafts from living donors, donors after cardiac death, and steatotic donors have been considered as promising sources of organs for liver transplantation and are associated with high incidence of liver graft injury. The acute-phase liver graft injury will trigger a series of inflammatory cascades, which may not only activate the cell signaling pathways regulating the tumor cell invasion and migration but also mobilize the circulating progenitor and immune cells to facilitate tumor recurrence and metastasis. The injured liver graft may also provide the favorable microenvironment for tumor cell growth, migration, and invasion through the disturbance of microcirculatory barrier function, induction of hypoxia and angiogenesis. This review aims to summarize the latest findings about the role and mechanisms of liver graft injury resulted from hepatic ischemia reperfusion injury on tumor recurrence posttransplantation, both in clinical and animal cohorts.

Prognostic factors after curative resection hepatocellular carcinoma and the surgeon's role

Purpose

Patient, surgical, and tumor factors affect the outcome after surgical resection for hepatocellular carcinoma (HCC). The surgical factors are only modifiable by the surgeon. We reviewed our experience with curative resection for HCC in terms of surgical factors.

Methods

After analyses of the prospectively collected clinical data of 256 consecutive patients undergoing surgical resection for HCC, prognostic factors for disease-free survival (DFS) and overall survival (OS) were identified; all patients were stratified by tumor diameters > or <5 cm and their outcomes were compared.

Results

Multivariate analyses showed that microvascular invasion, estimated blood loss, blood transfusion, and the number of tumors were independent adverse prognostic factors for DFS, whereas microvascular invasion, serum alpha fetoprotein, and tumor diameter were independent adverse prognostic factors for OS. Blood transfusion had borderline significance (P = 0.076). After stratification by tumor diameter, blood transfusion was only associated with poor DFS and OS in patients with tumor diameters > 5 cm.

Conclusion

Tumor recurrence after liver resection for HCC depends on tumor status, bleeding, and transfusions, which subsequently lead to poor patient survival. Surgeons can help improve the prognosis of patients by minimizing blood loss and transfusion, particularly in patients with larger tumors.

Hypoxia-activated prodrugs in the treatment of advanced pancreatic adenocarcinoma

Pancreatic cancer is an aggressive malignancy with poor survival and high mortality rate with 250 000 deaths per year worldwide. The unique pancreatic cancer microenvironment serves as a major obstacle in the effective treatment of this malignancy. The microenvironment consists not only of pancreatic ductal adenocarcinoma cells but also comprises cells of pancreatic cancer stellate, vascular, and immune origin combined with a dense extracellular matrix containing collagen. The aforementioned pathology leads to an increased intratumor pressure combined with an erratic vascular proliferation within the tumor causing hypoxia and decreased drug delivery. This has led both scientists and clinicians to develop and study drugs with unique mechanisms of action to target the pancreatic cancer microenvironment. Herein, we discuss the pancreatic cancer hypoxic microenvironment, development of hypoxia-activated prodrugs, and results of trials utilizing those drugs to target pancreatic cancer.

Impact of intraoperative vascular occlusion during liver surgery on long-term outcomes: A systematic review and meta-analysis

OBJECTIVE

To determine the impact of intraoperative vascular occlusion during liver surgery on postoperative long-term outcomes for hepatocellular carcinoma (HCC) patients using a meta-analysis.

METHODS

A systematic literature search of PubMed, EMBASE, and Cochrane Central was conducted to discover relevant randomized controlled trials (RCTs) and observational studies. Studies that reported postoperative long-term outcomes; 1-, 3-, and 5-year overall survival (OS); and/or 1-, 3-, and 5-year recurrence-free survival (RFS) for both an observation group (vascular occlusion) and a control group (vascular non-occlusion) were included. Forest plots were performed to calculate the difference between the 2 groups. The Q statistic and the I² index statistic were used to assess heterogeneity. Publication bias was evaluated using Egger's test.

RESULTS

Four observational studies containing 2917 patients were included in this meta-analysis. The pooled estimation results indicated that intraoperative vascular occlusion would not shorten the postoperative OS (RR = 1.01; 95%CI: 0.98-1.03; P = 0.763) and would not increase the risk of HCC recurrence (RR = 0.99; 95%CI: 0.97-1.02; P = 0.320) with low heterogeneity (I² = 0.0% and 12.7%, respectively). Furthermore, Egger's test did not reveal any publication bias (P = 0.405 and P = 0.269, respectively) in this research.

CONCLUSIONS

Intraoperative vascular occlusion during liver surgery is safe for HCC patients. It does not affect the postoperative overall survival or increase the risk of HCC recurrence.

NLRP3 inflammasome induced liver graft injury through activation of telomere-independent RAP1/KC axis

Acute-phase inflammation plays a critical role in liver graft injury. Inflammasomes, multi-molecular complexes in the cytoplasm, are responsible for initiating inflammation. Here, we aimed to explore the role of inflammasomes in liver graft injury and further to investigate the regulatory mechanism. In a clinical liver transplant cohort, we found that intragraft expression of nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3) inflammasomes was significantly up-regulated post-transplantation. Importantly, overexpression of NLRP3 was strongly associated with poor liver function characterized by high levels of ALT, AST, and urea, as well as neutrophil infiltration after transplantation. The significant correlation between NLRP3 and IL-1β mRNA levels led us to focus on one of the associated upstream regulators, telomere-independent repressor activator protein 1 (RAP1), which was further proved to be co-localized with NLRP3 in neutrophils. In the liver of a mouse model (hepatic ischaemia/reperfusion and hepatectomy model) and isolated neutrophils from RAP1^-/- mice, the expression levels of NLRP3 and keratinocyte chemoattractant (KC) were significantly down-regulated in contrast to those in wild types. The levels of ALT and AST, as well as the neutrophil infiltration, were also decreased by RAP1 deficiency. In our clinical validation, intragraft KC expression was associated with NLRP3 and co-localized with RAP1 in neutrophils. Furthermore, NLRP3 inflammasomes were up-regulated by recombinant KC in the isolated neutrophils and liver of the mouse model. Our data demonstrated that NLRP3 inflammasomes, activated by the RAP1/KC axis, played a critical role in initiating inflammation during the early stage of liver graft injury. Targeting RAP1/KC/NLRP3 inflammasomes may offer a new therapeutic strategy against liver graft injury. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Liver transplantation for hepatocellular carcinoma: outcomes and novel surgical approaches

Liver transplantation for hepatocellular carcinoma (HCC) is the best treatment option for patients with early-stage tumours and accounts for ∼20-40% of all liver transplantations performed at most centres worldwide. The Milan criteria are the most common criteria to select patients with HCC for transplantation but they can be seen as too restrictive. Several proposals have been made for a moderate expansion of the criteria, which result in good outcomes but with an increase in the risk of tumour recurrence. In this Review, we provide a comprehensive overview of the outcomes after liver transplantation for HCC, focusing on tumour recurrence in terms of surveillance, prevention and treatment. Additionally, novel surgical techniques have been developed to increase the available pool of organs for liver transplantation (such as living donor liver transplantation, donation after circulatory death and split livers), but the effect of these techniques on patients with HCC is still under debate. Thus, we will describe these techniques and expose the benefits and disadvantages of each surgical approach. Finally, we will comment on the limitations of the current priority policies for liver transplantation and the need to further refine them to better serve the population.

Outcomes utilizing imported liver grafts for recipients with hepatocellular carcinoma

Liver transplantation (LT) offers the best chance of survival in selected patients with hepatocellular carcinoma (HCC). Wait-list mortality or dropout due to tumor progression can be significant, and therefore, timely transplantation is critical. Liver grafts discarded by outside organ procurement organizations are a potential source of grafts for low Model for End-Stage Liver Disease tumor patients. The primary aim of this study was to assess the disease-free and overall survival of patients with HCC transplanted with imported liver grafts (ILGs). Review of all patients transplanted for HCC between June 2005 and December 2014 was performed. Data on demographics, survival, and HCC recurrence were analyzed. During this time period, 59 out of 190 (31%) recipients with HCC received ILG. Of these 59 grafts, 54 were imported from within the region and 5 were from national offers (outside the region). The mean cold ischemia time for local liver grafts (LLGs) was 4.1 ± 1.5 hours versus 5.1 ± 1.4 hours for ILG (P < 0.001). The 1-, 3-, and 5-year patient survival was 90%, 85%, and 83% and 85%, 80%, and 79% for LLG and ILG (P = 0.08), respectively. The observed disease recurrence rate for both LLG and ILG recipients was equivalent. The median wait-list time for HCC recipients was 43 days (range, 2-1167 days). In conclusion, with careful graft assessment, the use of ILGs results in comparable outcomes following LT and no increased risk of HCC recurrence. Use of ILGs maximizes the donor pool and results in a higher rate of transplantation for HCC recipients. Liver Transplantation 23 299-304 2017 AASLD.

Adverse impact of intermittent portal clamping on long-term postoperative outcomes in hepatocellular carcinoma

Introduction To evaluate the impact of intermittent portal clamping (IPC) on long-term postoperative outcomes in patients with hepatocellular carcinoma (HCC). Methods Clinical records of 355 patients underwent curative liver resection for HCC in January 2007 to December 2010 were retrospectively reviewed. According to how portal clamping was performed, patients were grouped as: IPC, n=113; other portal clamping (OPC), n=190; and no portal clamping (NPC), n=52. Results Median recurrence-free survival (RFS) was statistically significantly shorter in the IPC (39.4 months) than OPC (47.3 months, p=0.010) and NPC groups (51.4 months, p=0.008). Median overall survival (OS) was also significantly shorter with IPC (46.3 months), versus 52.9 months with OPC (p=0.022) and 56.2 months with NPC (p=0.015). Kaplan-Meier survival analysis revealed that 5-year cumulative RFS was much lower in the IPC (42.5%) than OPC (50.9%, p=0.014) and NPC groups (49.6%, p=0.013). Five-year cumulative OS was also much lower in the IPC (44.9%) than OPC (58.0%, p=0.020) and NPC groups (57.7%, p=0.025). On univariate analysis, tumour grade, size and number, TNM stage, blood transfusion, vascular invasion and IPC were significantly inversely correlated with RFS and OS. On multivariate analysis, tumour size and number, blood transfusion, vascular invasion and IPC remained significant. Conclusions Our study suggests that IPC is an independent risk factor for poor long-term postoperative outcomes in patients with HCC.

Longer warm ischemia can accelerate tumor growth through the induction of HIF-1α and the IL-6-JAK-STAT3 signaling pathway in a rat hepatocellular carcinoma model

BACKGROUND

The present study aimed to investigate the impact of the duration of hepatic pedicle clamping (HPC) on tumor growth after major hepatectomy in a rat model.

METHODS

Rats were divided into four groups according to the length of HPC during 70% partial hepatectomy followed by N1S1 tumor cell implantation: group 1, without HPC; group 2, with 5-min HPC; group 3, 10-min HPC; and group 4, 15-min HPC. At three weeks after tumor cell implantation, liver tumor growth and its possible mechanisms were investigated.

RESULTS

The number and largest diameter of liver tumor were significantly greater in group 4. At 6 h after reperfusion, serum levels of inflammatory cytokines including interleukin (IL)-6 were significantly higher in group 4 compared with the other groups. In the tumor tissues, the expression of hypoxia inducible factor (HIF)-1α (P < 0.001 versus group 2, P < 0.001 versus group 3) and that of phospho-signal transducer and activator of transcription 3 (STAT3) (P < 0.001 versus group 2, P = 0.026 versus group 3) were significantly upregulated in group 4.

CONCLUSIONS

Longer HPC followed by reperfusion accelerated hepatocellular carcinoma growth through the induction of HIF-1α and the activation of the IL-6-JAK-STAT3 signaling pathway.

CXCL10/CXCR3 signaling mobilized-regulatory T cells promote liver tumor recurrence after transplantation

BACKGROUND & AIMS

Liver graft injury and tumor recurrence are the major challenges of liver transplantation for the patients with hepatocellular carcinoma (HCC). Here, we aimed to explore the role and mechanism of liver graft injury mobilizing regulatory T cells (Tregs), which lead to late phase tumor recurrence after liver transplantation.

METHODS

The correlation among tumor recurrence, liver graft injury and Tregs mobilization were studied in 257 liver transplant recipients with HCC and orthotopic rat liver transplantation models. The direct roles of CXCL10/CXCR3 signaling on Tregs mobilization and tumor recurrence were investigated in CXCL10^-/- and CXCR3^-/- mice models with hepatic IR injury.

RESULTS

Clinically, patients received the graft with graft weight ratio (GWR) <60% had higher HCC recurrence after liver transplantation than the recipients with GWR ⩾60% graft. More circulating Tregs and higher intragraft TLR4/CXCL10/CXCR3 levels were detected in recipients with GWR <60% graft. These results were further validated in rat transplantation model. Foxp3⁺ cells and expressions of TLR4, CXCL10, TGFβ, CTLA-4 and CD274 were increased in rat liver tumor tissues from small-for-size graft group. In mouse model, the mobilization and recruitment of Tregs were decreased in TLR4^-/-, CXCL10^-/- and CXCR3^-/- mice compared to wild-type mice. Moreover, less CXCR3⁺ Tregs were recruited into liver in CXCL10^-/- mice after hepatic IR injury. The knockout of CXCL10 and depletion of Tregs inhibited tumor recurrence after hepatic IR injury.

CONCLUSION

CXCL10/CXCR3 signaling upregulated at liver graft injury directly induced the mobilization and intragraft recruitment of Tregs, which further promoted HCC recurrence after transplantation.

LAY SUMMARY

There were positive correlation among tumor recurrence, circulating Tregs and liver graft injury after human transplantation for HCC patients. The knockout of CXCL10 decreased hepatic recruitment of CXCR3⁺ Tregs and late phase tumor recurrence after hepatic IR injury.