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The mammalian target of rapamycin (mTOR) pathway is frequently deregulated and has critical roles in cancer progression. mTOR inhibitor has been widely used in several kinds of cancers and is strongly recommended in patients with hepatocellular carcinoma (HCC) after liver transplantation (LT). However, the poor response to mTOR inhibitors due to resistance remains a challenge. Hypoxia-associated resistance limits the therapeutic efficacy of targeted drugs. The present study established models of HCC clinical samples and cell lines resistance to mTOR inhibitor sirolimus and screened out E2F7 as a candidate gene induced by hypoxia and promoting sirolimus resistance. E2F7 suppressed mTOR complex 1 via directly binding to the promoter of the TSC1 gene and stabilizes hypoxia-inducible factor-1α activating its downstream genes, which are responsible for E2F7-dependent mTOR inhibitor resistance. Clinically, low E2F7 expression could be an effective biomarker for recommending patients with HCC for anti-mTOR-based therapies after LT. Targeting E2F7 synergistically inhibited HCC growth with sirolimus in vivo. E2F7 is a promising target to reverse mTOR inhibition resistance. Collectively, our study points to a role for E2F7 in promoting mTOR inhibitor resistance in HCC and emphasizes its potential clinical significance in patients with HCC after LT.

Liver transplantation (LT) is the only effective method of treating end-stage liver disease, such as various types of liver failure. China has the largest number of patients with hepatitis B virus-related disease, which is also the main cause of liver failure. From the first LT performed in 1977, and especially over the past two decades, LT has experienced rapid development as a result of continuous research and innovation in China. China performs the second-highest number of LTs every year worldwide, and the quality of LT continues to improve. Starting January 1, 2015, all donor's livers have been from deceased donors and familial donors. Thus, China entered into a new era of LT. However, LT is still a challenging procedure in China. In this review, we introduced the brief history of LT in China, the epidemiology, aetiology and clinical outcomes of LT for liver failure in China and summarized the experience of LT from Chinese LT surgeons and scholars. The future perspectives of LT were also discussed, and it is expected that China's LT research could be further integrated elsewhere in the world.

Background The use of the immunosuppressive agent sirolimus (SRL) following liver transplantation (LT) in patients with hepatocellular carcinoma (HCC) is controversial. Sirolimus is a typical mammalian target of rapamycin (mTOR) inhibitor, and tuberous sclerosis 1-tuberous sclerosis 2 complex (TSC1/TSC2) is an important negative effector in the mTOR pathway. In this study, we investigated the effect of SRL-based immunosuppression on the prognosis of LT recipients with HCC beyond the Milan criteria based on TSC1/2 expression and explored the effect of TSC1 on HCC in vitro and in vivo. Methods We retrospectively analyzed 120 HCC patients who underwent LT in our hospital between January 1, 2015 and December 30, 2018. All patients had HCC beyond the Milan criteria and were divided into the SRL group (n = 50) and non-SRL group (n = 70). TSC1/2 expression levels in paraffin-embedded tissues were determined by immunohistochemistry (IHC) and then analyzed as subgroups. Overall survival (OS) and disease-free survival (DFS) were analyzed using the Kaplan-Meier method. TSC1 expression was silenced in Huh-7 and Bel-7402 cell lines for further cell function experiments. Results 88.3% of patients were HBV LT recipients. The SRL group exhibited better DFS and OS compared to the non-SRL group (P = 0.02, P = 0.003). Subgroup (TSC1-based or TSC2-based) analyses revealed that patients with low TSC1 or TSC2 expression benefited from sirolimus (DFS: P = 0.046, OS: P = 0.006 for TSC1; DFS: P = 0.05, OS: P = 0.003 for TSC2) compared with patients with high expression. TSC1 knockdown in Huh-7 and Bel-7402 HCC cell lines activated the mTORC1 pathway and enhanced cell proliferation, migration and sensitivity to SRL in vitro and in vivo. Conclusion TSC1/2 expression could be used to predict the prognosis of patients with HCC beyond the Milan criteria who underwent SRL-based immunosuppression following LT. TSC1 knockdown promoted HCC malignancy and enhanced sensitivity to SRL.

Recently, many studies have shown that deubiquitination modification of proteins is of great significance in major physiological processes such as cell proliferation, apoptosis, and differentiation. The ubiquitin-specific peptidase (USP) family is one of the most numerous and structurally diverse of the deubiquitinates known to date. USP22, an important member of the USP family, has been found to be closely associated with tumor cell cycle regulation, stemness maintenance, invasion and metastasis, chemoresistance, and immune regulation. We focus on recent advances regarding USP22's function in cancer and discuss the prospect of USP22 in this review.

The downstaging of hepatocellular carcinoma (HCC) has been confirmed to benefit liver transplantation (LT) patients whose tumors are beyond the transplantation criteria. Milan criteria (MC), a tumor size and number-based assessment, is currently used as the endpoint in these patients. However, many studies believe that tumor biological behavior should be added to the evaluation criteria for downstaging efficacy. Hence, this study aimed to explore the feasibility of Hangzhou criteria (HC), which introduced tumor grading and alpha-fetoprotein in addition to tumor size and number, as an endpoint of downstaging.We performed a multicenter and retrospective study of 206 patients accepted locoregional therapy (LRT) as downstaging/bridge treatment prior to LT in three centers of China.Recipients were divided into four groups: failed downstaging to the HC (group A, n = 46), successful downstaging to the HC (group B, n = 30), remained within the HC all the time (group C, n = 113), and tumor progressed (group D, n = 17). The 3-year HCC recurrence probabilities of groups B and C were not significantly different (10.3% vs. 11.6%, P = 0.87). The HCC recurrent rate was significantly higher in group A (52.3%) compared with that in group B/C (P 0.05). Seven patients (7/76, 9.2%) whose tumor exceeded the the HC were successfully downstaged to the MC, and 39.5% (30/76) to the the HC. In group B, 23 patients remained beyond the MC and their survivals were as well as those of patients within the MC.Compared to the MC, HC downstaging criteria can give more HCC patients access to LT and furthermore, the outcome of these patients is the same as those matching MC downstaging criteria. Hangzhou downstaging criteria therefore is applicable in clinical practice.

Liang Zhang,1,* Zhentao Yang,1,* Shiyu Zhang,1 Ke Zhou,1 Wu Zhang,2 Sunbin Ling,1 Ruiqi Sun,1 Hong Tang,1 Xue Wen,3 Xiaowen Feng,1 Penghong Song,1 Xiao Xu,1 Haiyang Xie,1 Shusen Zheng1,2 1Division of Hepatobiliary and Pancreatic Surgery, Department of Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Key Laboratory of the Diagnosis and Treatment of Organ Transplantation, Research Unit of Collaborative Diagnosis and Treatment for Hepatobiliary and Pancreatic Cancer, Chinese Academy of Medical Sciences (2019RU019), Hangzhou, Zhejiang, 310003, People’s Republic of China; 2Department of Hepatobiliary and Pancreatic Surgery, Shulan (Hangzhou) Hospital, Hangzhou, Zhejiang, 310004, People’s Republic of China; 3Department of Pathology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, 310003, People’s Republic of China*These authors contributed equally to this workCorrespondence: Haiyang Xie; Shusen ZhengSchool of Medicine, Zhejiang University, 79# Qingchun Road, Hangzhou, Zhejiang, 310000, People’s Republic of ChinaTel/Fax +86 571 87236570; +86 571 87236466Email xiehy@zju.edu.cn; shusenzheng@zju.edu.cnPurpose: Patients receiving liver transplantation (LT) for hepatocellular carcinoma (HCC) are at high risk of tumor recurrence. Polyploidy is a fascinating characteristic of the liver and correlates with HCC development and progression. This study aims to investigate the association between hepatocyte polyploidy spectrum and HCC recurrence after LT.Patients and Methods: Thirty-two paired HCC, peritumoral, cirrhotic, and normal liver specimens were employed to examine the hepatocyte polyploidization pattern during liver tumorigenesis. Clinicopathological implications of polyploidy spectrum for LT recipients with HCC were investigated in 205 patients from two transplant centers. Immunofluorescence staining was performed on paraffin-embedded tissue sections to determine the ploidy profiles in situ. Expression levels of CD4, CD8, forkhead box protein 3 (Foxp3) and programmed death-ligand 1 (PD-L1) were measured using immunohistochemistry. An array-based multiplex ELISA system was used for the quantitative measurement of 40 unique inflammatory cytokines.Results: The fraction of mononuclear polyploidy increased, whereas that of binuclear polyploidy reduced during hepatocarcinogenesis. Recipients with highly mononuclear polyploid HCC (HMP–HCC) had inferior recurrence-free survival and HCC-specific survival than poorly mononuclear polyploid HCC recipients. These two groups differed in abundance of infiltrative CD8+ cytotoxic T cells and FoxP3+ Treg cells, and PD-L1 expression, as well as circulating granulocyte–macrophage colony-stimulating factor, interferon-γ and interleukin-10 levels. HMP–HCC constituted an independent recurrence predictor and could improve the discriminative efficacy of clinical prediction models (Milan criteria, AFP model, and Metroticket 2.0 criteria). A scoring system incorporating the ploidy signature was developed and validated, allowing for an improved risk prediction relative to the RETREAT score and post-MORAL score.Conclusion: Polyploid spectra are associated with tumor immunophenotype and provide supplementary prognostic information in LT for HCC.Keywords: polyploidy, immunosurveillance, tumor-infiltrating lymphocytes, cytokines, tumor recurrence

Quiescence has been observed in stem cells (SCs), including adult SCs and cancer SCs (CSCs). Conventional chemotherapies mostly target proliferating cancer cells, while the quiescent state favors CSCs escape to chemotherapeutic drugs, leaving risks for tumor recurrence or metastasis. The tumor microenvironment (TME) provides various signals that maintain resident quiescent CSCs, protect them from immune surveillance, and facilitates their recurrence potential. Since the TME has the potential to support and initiate stem cell-like programs in cancer cells, targeting the TME components may prove to be a powerful modality for the treatment of chemotherapy resistance. In addition, an increasing number of studies have discovered that CSCs exhibit the potential of metabolic flexibility when metabolic substrates are limited, and display increased robustness in response to stress. Accompanied by chemotherapy that targets proliferative cancer cells, treatments that modulate CSC quiescence through the regulation of metabolic pathways also show promise. In this review, we focus on the roles of metabolic flexibility and the TME on CSCs quiescence and further discuss potential treatments of targeting CSCs and the TME to limit chemotherapy resistance.

Aim Glutamine synthetase (GS) levels increase gradually with the development of hepatocellular carcinogenesis. In this study, we aimed to investigate the clinical significance of GS and the underlying mechanism of GS promoting hepatocellular carcinoma (HCC) invasion. Methods Serum concentration of GS and α-fetoprotein (AFP) in HCC patients, liver cirrhosis patients, and healthy individuals were detected. The GS-mRNA level and its prognostic value were explored in an independent HCC cohort from The Cancer Genome Atlas database. GS expression in HCC tissue and matched para-tumor tissue was determined. The effect of GS on HCC invasion was assessed in vitro and in vivo. Results The serum GS and AFP level in HCC patients was higher than that in healthy controls and liver cirrhosis patients. The area under the receiver operating characteristic curve for HCC diagnosis was 0.848 and 0.861 for GS and AFP, respectively. The area under the receiver operating characteristic curve of GS for diagnosis of AFP-negative HCC was 0.913. Combining GS with AFP achieved a diagnostic sensitivity and specificity of 82.5% and 93%, respectively. The GS level was higher in tumor tissues than that in para-tumor tissues. High GS expression was associated with poor prognosis of moderately differentiated HCC patients. In vitro, GS exerted an influence on HCC cell migration by mediating epithelial-mesenchymal transition. The lung and liver metastatic model of HCC further confirmed that GS expression affected the invasion of HCC cells in vivo. Conclusions GS is a useful biomarker for HCC diagnosis, especially for AFP-negative patients. In addition, GS affects HCC metastasis through mediating epithelial-mesenchymal transition.

Background Ubiquitin-specific protease 22 (USP22) is described as a key subunit of the Spt-Ada-Gcn5 acetyl transferase complex, which plays an important role in the prognosis and resistance to chemotherapy drugs in hepatocellular carcinoma (HCC). Silent information regulator 1 (SIRT1) is a member of the sirtuin family that is deubiquitinated by USP22. However, it is still unknown whether USP22 and SIRT1 co-expression is associated with disease progression and 5-Fluorouracil (5-FU) resistance in HCC. Methods 141 patients who received hepatectomy at our hospital from January 2010 to December 2014 were enrolled in this study. The expression of USP22 and SIRT1 was detected by immunohistochemical staining. Clinicopathological features, including age, gender, tumor number, tumor size, tumor differentiation, tumor stage, alpha-fetoprotein and microscopic vascular invasion, were assessed. Further experiments confirmed the role of SIRT1 in 5-FU drug resistance in vivo. Results Immunohistochemical staining showed that the high expression of USP22 and SIRT1 was frequently observed in HCC tissues relative to normal liver tissues. Overexpression of USP22 is associated with microscopic vascular invasion (MVI). Further analysis showed that the co-expression of USP22 and SIRT1 was more effective in predicting the prognosis of HCC. The SIRT1 inhibitor EX-527 dramatically inhibited the expression of Cyclin B1 and resistance-associated protein 3 (MRP3) to reduce 5-FU drug resistance in vivo. Conclusion These findings suggest that the co-expression of USP22 and SIRT1 is significantly associated with unfavorable HCC progression. The inhibition of SIRT1 in vivo could be valuable in improving 5-FU drug sensitivity and inhibiting tumor cell proliferation and inducing apoptosis.

Background and objectivesPulsed radiofrequency (PRF) is a minimal neurodestructive interventional pain therapy. However, its analgesic mechanism remains largely unclear. We aimed to investigate the peripheral and spinal mechanisms of PRF applied either adjacent to the ipsilateral L5 dorsal root ganglion (PRF-DRG) or PRF to the sciatic nerve (PRF-SN) in the neuropathic pain behavior induced by chronic constriction injury (CCI) in rats.MethodsOn day 0, CCI or sham surgeries were performed. Rats then received either PRF-DRG, PRF-SN, or sham PRF treatment on day 4. Pain behavioral tests were conducted before surgeries and on days 1, 3, 5, 7, 9, 11, 13, and 14. After the behavioral tests, the rats were sacrificed. The venous blood or sciatic nerve samples were collected for ELISAs and the dorsal horns of the L4–L6 spinal cord were collected for western blot examination.ResultsThe mechanical allodynia and the thermal hyperalgesia has been relieved by a single PRF-DRG or PRF-SN application. In addition, the analgesic effect of PRF-DRG was superior to PRF-SN on CCI-induced neuropathic pain. Either PRF-DRG or PRF-SN reversed the enhancement of interleukin 1β (IL-1β) and tumor necrosis factor alpha (TNF-α) levels in the blood of CCI rats. PRF-DRG or PRF-SN also downregulated spinal β-catenin expression.ConclusionsPRF treatment either to DRG or to sciatic nerve reduced neuropathic pain behavior, and reduced peripheral levels of pro-inflammatory cytokines and spinal β-catenin expression in CCI rats. PRF to DRG has a better analgesic effect than PRF to the nerve.

Background Palliative resection of the primary tumor for metastatic pancreatic neuroendocrine carcinoma (pNEC) patients is not recommended because of the poor prognosis compared to that of patients with well-differentiated, lower grade tumors. However, the published data supporting this recommendation regarding pNEC are limited. In the present study, we assessed whether palliative primary tumor resection in stage IV pNEC patients affects survival and identified other factors that affect survival in these patients. Methods We collected data from stage IV pNEC patients registered in the Surveillance, Epidemiology, and End Results (SEER) database between 1988 and 2014. Univariate and multivariate Cox regression analysis were used to compare overall survival (OS) and cancer-specific survival (CSS) of patients who did or did not undergo primary tumor resection. Results We identified 350 patients with metastatic, poorly differentiated, and undifferentiated pNEC. A total of 14.3% (50/350) of patients underwent primary tumor resection. Multivariate Cox regression analysis showed that primary tumor resection provided a significant benefit for both OS and CSS in stage IV pNEC patients. Additionally, chemotherapy and the presence of the primary tumor in the pancreatic tail were independent positive prognostic factors for metastatic pNEC patients in the multivariate Cox regression analysis. Conclusions The present study suggests that chemotherapy, location of the primary tumor in the pancreatic tail, and, most importantly, surgical removal of the primary tumor are associated with prolonged survival in stage IV pNEC patients. Electronic supplementary material The online version of this article (10.1186/s12957-019-1597-5) contains supplementary material, which is available to authorized users.

Menin and glucagon-like peptide 1 (GLP-1) pathways play central yet opposing roles in regulating β cell function, with menin suppressing and GLP-1 promoting β cell function. Xing et al show that GLP-1 induces PKA-mediated phosphorylation of menin. Phosphorylation of menin triggers its interaction with nuclear actin to relieve menin’s transcriptional repression and increase insulin production., Both menin and glucagon-like peptide 1 (GLP-1) pathways play central yet opposing role in regulating β cell function, with menin suppressing, and GLP-1 promoting, β cell function. However, little is known as to whether or how GLP-1 pathway represses menin function. Here, we show that GLP-1 signaling–activated protein kinase A (PKA) directly phosphorylates menin at the serine 487 residue, relieving menin-mediated suppression of insulin expression and cell proliferation. Mechanistically, Ser487-phosphorylated menin gains increased binding affinity to nuclear actin/myosin IIa proteins and gets sequestrated from the Ins1 promoter. This event leads to reduced binding of repressive epigenetic histone modifiers suppressor variegation 3–9 homologue protein 1 (SUV39H1) and histone deacetylases 1 (HDAC1) at the locus and subsequently increased Ins1 gene transcription. Ser487 phosphorylation of menin also increases expression of proproliferative cyclin D2 and β cell proliferation. Our results have uncovered a previously unappreciated physiological link in which GLP-1 signaling suppresses menin function through phosphorylation-triggered and actin/myosin cytoskeletal protein–mediated derepression of gene transcription.

Background. PDZ binding kinase (PBK)/T-LAK cell-derived protein kinase (TOPK) is an important mitotic kinase that promotes tumor progression in some cancers. However, the pan-cancer analysis of PBK/TOPK and its role in tumor immunity are limited. Methods. The oncogenic and immune roles of PBK in various cancers were explored using multiple databases, including Oncomine, Human Protein Atlas, ULCAN, Tumor Immune Estimation Resource 2.0, STRING, and Gene Expression Profiling Interactive Analysis 2, and data collected from The Cancer Genome Atlas and Genotype-Tissue Expression Project. Several bioinformatics tools and methods were used for quantitative analyses and panoramic descriptions, such as the DESeq2 and Tumor Immune Dysfunction and Exclusion (TIDE) algorithm. Results. PBK was expressed at higher levels in most solid tumors than in normal tissues in multiple databases. PBK was associated with an advanced tumor stage and grade and a poor prognosis in most cases. PBK was associated with tumor immune cell infiltration in most cases and was especially positively correlated with TAMs, Tregs, MDSCs, and T cell exhaustion in KIRC, LGG, and LIHC. PBK was closely related to TMB, MSI, and immune checkpoint genes in various cancers, and patients with higher expression of PBK in KIRC, LGG, and LIHC had higher TIDE scores and lower immune responses in the predicted results. PBK was closely related to cell cycle regulation and immune-related processes in LIHC and LGG according to GO and KEGG enrichment analyses. Conclusions. PBK may play an oncogenic role in most solid tumors and promotes immune escape, especially in KIRC, LGG, and LIHC. This study suggests the potential value of PBK inhibitors combined with immunotherapy.

Pancreatic beta cells undergo compensatory proliferation in the early phase of type 2 diabetes. While pathways such as FoxM1 are involved in regulating compensatory beta cell proliferation, given the lack of therapeutics effectively targeting beta cell proliferation, other targetable pathways need to be identified. Herein, we show that Pbk, a serine/threonine protein kinase, is essential for high fat diet (HFD)‐induced beta cell proliferation in vivo using a Pbk kinase deficiency knock‐in mouse model. Mechanistically, JunD recruits menin and HDAC3 complex to the Pbk promoter to reduce histone H3 acetylation, leading to epigenetic repression of Pbk expression. Moreover, menin inhibitor (MI) disrupts the menin–JunD interaction and augments Pbk transcription. Importantly, MI administration increases beta cell proliferation, ameliorating hyperglycemia, and impaired glucose tolerance (IGT) in HFD‐induced diabetic mice. Notably, Pbk is required for the MI‐induced beta cell proliferation and improvement of IGT. Together, these results demonstrate the repressive role of the menin/JunD/Pbk axis in regulating HFD‐induced compensatory beta cell proliferation and pharmacologically regulating this axis may serve as a novel strategy for type 2 diabetes therapy., Pancreatic beta cells undergo compensatory proliferation in the early phase of type 2 diabetes. Understanding the mechanism and regulation of compensatory beta cell proliferation may allow for improved treatment options for diabetes. Herein we elucidated that the menin/JunD/Pbk axis is important in compensatory beta‐cell proliferation.

The incidence of portal vein tumor thrombus (PVTT) has been reported to be as high as approximately 10%-40% in patients with hepatocellular carcinoma (HCC). The long-term prognosis of deceased donor liver transplantation (DDLT) in HCC patients with PVTT remains unknown.Data of 961 HCC patients who underwent DDLT between 2015 and 2018 in six centers were analyzed. Based on the Milan criteria (MC) and Cheng's classification of PVTT, the patients were divided into 4 groups: within MC, beyond MC without PVTT, type 1 PVTT, and type 2 PVTT groups.489 (50.9%) were within the MC, 296 (30.8%) beyond the MC but without PVTT, 83 (8.6%) type 1 PVTT, and 93 (9.7%) type 2 PVTT. Kaplan-Meier analysis showed that type 1 or 2 PVTT patients with alpha-fetoprotein (AFP) ≤ 100 ng/mL had overall survival (OS) similar to that of patients within the MC (P = 0.957), and superior OS (P = 0.003 and 0.009) and recurrence-free survival (RFS) (P = 0.038 and 0.001) than those of patients beyond the MC and PVTT patients with AFP 100 ng/mL. Multivariable Cox-regression analysis identified type 1 and 2 PVTT to be independent risk factor for RFS [hazard ratio (HR) 1.523 95% confidence interval (CI) 1.162-1.997, P = 0.002], but not for OS (HR 1.283, 95%CI 0.922-1.786, P = 0.139).HCC patients with type 1 or 2 PVTT may be acceptable candidates for DDLT. To achieve better outcomes, preoperative AFP levels should be seriously considered when selecting patients with PVTT for DDLT.

Mammalian target of rapamycin (mTOR) inhibitor as an attractive drug target with promising antitumor effects has been widely investigated. High quality clinical trial has been conducted in liver transplant (LT) recipients in Western countries. However, the pertinent studies in Eastern world are paucity. Therefore, we designed a clinical trial to test whether sirolimus can improve recurrence-free survival (RFS) in hepatocellular carcinoma (HCC) patients beyond the Milan criteria after LT. This is an open-labeled, single-arm, prospective, multicenter, and real-world study aiming to evaluate the clinical outcomes of early switch to sirolimus-based regimens in HCC patients after LT. Patients with a histologically proven HCC and beyond the Milan criteria will be enrolled. The initial immunosuppressant regimens are center-specific for the first 4-6 weeks. The following regimens integrated sirolimus into the regimens as a combination therapy with reduced calcineurin inhibitors based on the condition of patients and centers. The study is planned for 4 years in total with a 2-year enrollment period and a 2-year follow-up. We predict that sirolimus conversion regimen will provide survival benefits for patients particular in the key indicator RFS as well as better quality of life. If the trial is conducted successfully, we will have a continued monitoring over a longer follow-up time to estimate indicator of overall survival. We hope that the outcome will provide better evidence for clinical decision-making and revising treatment guidelines based on Chinese population data. Trial register: Trial registered at http://www.chictr.org.cn: ChiCTR2100042869.

Background The trabecular pattern is one of the most common features of hepatocellular carcinoma (HCC). In this study, we aimed to identify the molecular mechanisms underlying different trabecular patterns in HCC, and their interaction with current therapies. Methods To screen potential biomarkers of different trabecular patterns, we first linked gene expression data to haematoxylin and eosin (H&E) images from The Cancer Genome Atlas (TCGA). The Gene Expression Omnibus (GEO) database was used to explore potential targets of sorafenib treatment. Selected candidate biomarkers were further verified by immunohistochemistry, and their relationship with sorafenib efficacy was evaluated in 107 HCC samples with trabecular patterns. Results Analysis of RNA sequencing data from TCGA showed that the increasing number of cells in the trabecular structure correlated with increase in the expression of related signalling pathways—Ras, Rap1, IL17, TNF, AGE-RAGE, oestrogen, toll-like receptor signalling, and ubiquitin-mediated proteolysis—and genes related to response to oxygen levels and neoangiogenesis. In contrast, the expression of bile acid and carton, tryptophan, butanoate, and lipid metabolism-related pathways was reduced. The GEO database showed that RAP1GAP, TOB1, ACO2, and SCNN1D expression levels were selectively up-regulated in sorafenib non-responders. Based on the combined analysis of the two datasets and our previous studies, two candidate biomarkers, RAP1GAP and HIF1α, were selected. Immunohistochemical staining showed that RAP1GAP and HIF1α were expressed in the tumour tissues. Interestingly, RAP1GAP was also expressed in the tumour sinusoids. Overexpression of RAP1GAP in sinusoids were associated with trabecular patterns. Multivariate analysis also showed that RAP1GAP expression in the sinusoid was an independent predictor of progressive free survival (PFS) and overall survival (OS) in response to sorafenib treatment. Conclusions RAP1GAP is an essential microenvironment marker in the trabecular structure of HCC and exhibits an adverse association with outcome in sorafenib treatment.

Liver transplantation (LT), one of the radical methods of treating liver cancer, has brought new hope for the treatment of unresectable liver cancer. Currently, patients who meet transplant criteria can achieve a favorable prognosis, but those who exceed transplant criteria tend not to have very satisfactory outcomes. For patients whose tumor burden exceeds the transplant criteria, downstaging treatment is a promising method to reduce tumor burden to within the transplant criteria that may lead to good posttransplant survival. Multiple treatments, such as transcatheter arterial chemoembolization (TACE), transarterial radioembolization (TARE), percutaneous ethanol injection (PEI), and radiofrequency ablation (RFA), have been used as downstaging treatments. However, there are still some issues that limit the effectiveness of downstaging treatments, such as the inclusion criteria for downstaging, which the choice of downstaging treatment method, and the endpoint of downstaging, all of which are worthy of further discussion. Based on the published literature, this review discusses these issues.

BACKGROUND: The administration of calcineurin inhibitors (CNIs) posttransplant has been implicated as an independent risk factor for the recurrence of hepatocellular carcinoma (HCC) after liver transplantation (LT). The new immunosuppressive agent sirolimus (SRL) acts as a primary immunosuppressant or antitumor agent. In this study we investigated the effect of sirolimus-based immunosuppression compared to CNIs (non-SRL) on the outcomes of LT candidates with HCC. METHODS: We retrospectively analyzed 204 HCC patients who underwent LT in our hospital between January 2, 2014 and December 10, 2017. The median of the follow-up duration of patients was 24.5 months. The patients were divided into a sirolimus (SRL) group (76 patients) and a non-sirolimus (non-SRL) group (128 patients). Patients exceeding the LT criteria were analyzed as subgroups. Disease-free survival (DFS) and overall survival (OS) after tumor recurrence were compared using the Kaplan-Meier method. Univariate and multivariate Cox analyses were used to compare OS between the SRL and non-SRL groups. RESULTS: The SRL group achieved better OS compared to the non-SRL group, while there was no significant difference in DFS. Subgroup (Milan criteria-based or Hangzhou criteria-based) analyses revealed that patients exceeding, rather than meeting, the Milan or Hangzhou criteria benefited from SRL (exceeding the Milan criteria: P=0.002; exceeding the Hangzhou criteria: P

Drug treatments for hepatocellular carcinoma (HCC) often fail because of multidrug resistance (MDR). The mechanisms of MDR are complex but cancer stem cells (CSCs), which are able to self-renew and differentiate, have recently been shown to be involved. The deubiquitinating enzyme ubiquitin-specific protease 22 (USP22) is a marker for CSCs. This study aimed to elucidate the role of USP22 in MDR of HCC and the underlying mechanisms. Using in vitro and in vivo assays, we found that modified USP22 levels were responsible for the altered drug-resistant phenotype of BEL7402 and BEL/FU cells. Downregulation of USP22 dramatically inhibited the expression of ABCC1 (encoding MRP1) but weakly influenced ABCB1 (encoding P-glycoprotein). Sirtuin 1 (SIRT1) was reported previously as a functional mediator of USP22 that could promote HCC cell proliferation and enhance resistance to chemotherapy. In this study, USP22 directly interacted with SIRT1 and positively regulated SIRT1 protein expression. Regulation of the expression of both USP22 and SIRT1 markedly affected the AKT pathway and MRP1 expression. Inhibition of the AKT pathway by its specific inhibitor LY294002 resulted in downregulation of MRP1. USP22 and MRP1 expression was detected in 168 clinical HCC samples by immunohistochemical staining, and a firm relationship between USP22 and MRP1 was identified. Together, these results indicate that USP22 could promote the MDR in HCC cells by activating the SIRT1/AKT/MRP1 pathway. USP22 might be a potential target, through which the MDR of HCC in clinical setting could be reversed.

Chimeric antigen receptor (CAR) T cells have radically improved the treatment of B cell–derived malignancies by targeting CD19. The success has not yet expanded to treat acute myeloid leukemia (AML). We developed a Sequentially Tumor-Selected Antibody and Antigen Retrieval (STAR) system to rapidly isolate multiple nanobodies (Nbs) that preferentially bind AML cells and empower CAR T cells with anti-AML efficacy. STAR-isolated Nb157 specifically bound CD13, which is highly expressed in AML cells, and CD13 CAR T cells potently eliminated AML in vitro and in vivo. CAR T cells bispecific for CD13 and TIM3, which are upregulated in AML leukemia stem cells, eradicated patient-derived AML, with much reduced toxicity to human bone marrow stem cells and peripheral myeloid cells in mouse models, highlighting a promising approach for developing effective AML CAR T cell therapy.

ObjectiveWe aimed to elucidate the mutual regulation mechanism of ubiquitin-specific protease 22 (USP22) and hypoxia inducible factor-1α (HIF1α), and the mechanism they promote the stemness of hepatocellular carcinoma (HCC) cells under hypoxic conditions.DesignCell counting, migration, self-renewal ability, chemoresistance and expression of stemness genes were established to detect the stemness of HCC cells. Immunoprecipitation, ubiquitination assay and chromatin immunoprecipitation assay were used to elucidate the mutual regulation mechanism of USP22 and HIF1α. HCC patient samples and The Cancer Genome Atlas data were used to demonstrate the clinical significance. In vivo USP22-targeting experiment was performed in mice bearing HCC.ResultsUSP22 promotes hypoxia-induced HCC stemness and glycolysis by deubiquitinating and stabilising HIF1α. As direct target genes of HIF1α, USP22 and TP53 can be transcriptionally upregulated by HIF1α under hypoxic conditions. In TP53 wild-type HCC cells, HIF1α induced TP53-mediated inhibition of HIF1α-induced USP22 upregulation. In TP53-mutant HCC cells, USP22 and HIF1α formed a positive feedback loop and promote the stemness of HCC. HCC patients with a loss-of-function mutation at TP53 and high USP22 and/or HIF1α expression tend to have a worse prognosis. The USP22-targeting lipopolyplexes caused high tumour inhibition and high sorafenib sensitivity in mice bearing HCC.ConclusionUSP22 promotes hypoxia-induced HCC stemness by a HIF1α/USP22 positive feedback loop on TP53 inactivation. USP22 is a promising target for the HCC therapy.

Resistance to sorafenib remains one of the biggest concerns for hepatocellular carcinoma treatment. In article number 2003042, Xiao Xu, Jiajia Xiang, and co‐workers developed a self‐activated sorafenib and USP22 shRNA codelivery nanoplatform (Gal‐SLP) to reverse cancer stemness and sensitive cancer cells to sorafenib. Gal‐SLP releases USP22 shRNA efficiently and enhances the intracellular sorafenib accumulation in cancer cells. Gal‐SLP exhibits potent antitumor efficiency in a sorafenibinsensitive patient‐derived xenograft (PDX) model. [Image: see text]

Resistance to sorafenib severely hinders its effectiveness against hepatocellular carcinoma (HCC). Cancer stemness is closely connected with resistance to sorafenib. Methods for reversing the cancer stemness remains one of the largest concerns in research and the lack of such methods obstructs current HCC therapeutics. Ubiquitin‐specific protease 22 (USP22) is reported to play a pivotal role in HCC stemness and multidrug resistance (MDR). Herein, a galactose‐decorated lipopolyplex (Gal‐SLP) is developed as an HCC‐targeting self‐activated cascade‐responsive nanoplatform to co‐delivery sorafenib and USP22 shRNA (shUSP22) for synergetic HCC therapy. Sorafenib, entrapped in the Gal‐SLPs, induced a reactive oxygen species (ROS) cascade and triggered rapid shUSP22 release. Thus, Gal‐SLPs dramatically suppressed the expression of USP22. The downregulation of USP22 suppresses multidrug resistance‐associated protein 1 (MRP1) to induce intracellular sorafenib accumulation and hampers glycolysis of HCC cells. As a result, Gal‐SLPs efficiently inhibit the viability, proliferation, and colony formation of HCC cells. A sorafenib‐insensitive patient‐derived xenograft (PDX) model is established and adopted to evaluate in vivo antitumor effect of Gal‐SLPs. Gal‐SLPs exhibit potent antitumor efficiency and biosafety. Therefore, Gal‐SLPs are expected to have great potential in the clinical treatment of HCC., A galactose‐decorated lipopolyplex (Gal‐SLP) is developed as a hepatocellular carcinoma (HCC)‐targeting self‐activated cascade‐responsive nanoplatform to co‐deliver sorafenib and USP22 shRNA (shUSP22) for synergetic HCC therapy. Gal‐SLP exhibited a trio synergetic effect and achieved potent antitumor efficiency against a sorafenib‐insensitive patient‐derived xenograft.

Table S1. Bone/brain/liver/pulmonary metastases in 25 patients with primary and metastatic lesions resection. (DOCX 17 kb)

Hepatocellular carcinoma (HCC) is one of the most common cancers and a leading cause of death worldwide. Due to latent liver disease, late diagnosis, and nonresponse to systemic treatments, surgical resection and/or biopsy specimens are still generally considered as the gold standard by clinicians for clinical decision-making until now. Since the conventional tissue biopsy is invasive and contains small tissue samples, it is unable to represent tumor heterogeneity or monitor dynamic tumor progression. Therefore, it is imperative to find a new less invasive or noninvasive diagnostic strategy to detect HCC at an early stage and to monitor HCC recurrence. Over the past years, a new diagnostic concept known as “liquid biopsy” has emerged with substantial attention. Liquid biopsy is noninvasive and allows repeated analyses to monitor tumor recurrence, metastasis or treatment responses in real time. With the advanced development of new molecular techniques, HCC circulating tumor cells (CTCs) and circulating tumor DNA (ctDNA) detection have achieved interesting and encouraging results. In this review, we focus on the clinical applications of CTCs and ctDNA as key components of liquid biopsy in HCC patients.

Background Arsenic trioxide (ATO) is commonly used in the treatment of acute promyelocytic leukemia (APL), but does not benefit patients with solid tumors. When combined with other agents or radiation, ATO showed treatment benefits with manageable toxicity. Previously, we reported that metformin amplified the inhibitory effect of ATO on intrahepatic cholangiocarcinoma (ICC) cells more significantly than other agents. Here, we investigated the chemotherapeutic sensitization effect of metformin in ATO-based treatment in ICC in vitro and in vivo and explored the underlying mechanisms. Methods ICC cell lines (CCLP-1, RBE, and HCCC-9810) were treated with metformin and/or ATO; the anti-proliferation effect was evaluated by cell viability, cell apoptosis, cell cycle, and intracellular-reactive oxygen species (ROS) assays. The in vivo efficacy was determined in nude mice with CCLP-1 xenografts. The active status of AMPK/p38 MAPK and mTORC1 pathways was detected by western blot. In addition, an antibody array was used screening more than 200 molecules clustered in 12 cancer-related pathways in CCLP-1 cells treated with metformin and/or ATO. Methods of genetic modulation and pharmacology were further used to demonstrate the relationship of the molecule. Seventy-three tumor samples from ICC patients were used to detect the expression of ERK3 by immunohistochemistry. The correlation between ERK3 and the clinical information of ICC patients were further analyzed. Results Metformin and ATO synergistically inhibited proliferation of ICC cells by promoting cell apoptosis, inducing G0/G1 cell cycle arrest, and increasing intracellular ROS. Combined treatment with metformin and ATO efficiently reduced ICC growth in an ICC xenograft model. Mechanistically, the antibody array revealed that ERK3 exhibited the highest variation in CCLP-1 cells after treatment with metformin and ATO. Results of western blot confirm that metformin and ATO cooperated to inhibit mTORC1, activate AMP-activated protein kinase (AMPK), and upregulate ERK3. Metformin abrogated the activation of p38 MAPK induced by ATO, and this activity was partially dependent on AMPK activation. Inactivation of p38 MAPK by SB203580 or specific short interfering RNA (siRNA) promoted the inactivation of mTORC1 in ICC cells treated with metformin and ATO. Activation of p38 MAPK may be responsible for resistance to ATO in ICC. The relationship between p38 MAPK and ERK3 was not defined by our findings. Finally, AMPK is a newfound positive regulator of ERK3. Overexpression of EKR3 in ICC cells inhibited cell proliferation through inactivation of mTORC1. ERK3 expression is associated with a better prognosis in ICC patients. Conclusions Metformin sensitizes arsenic trioxide to suppress intrahepatic cholangiocarcinoma via the regulation of AMPK/p38 MAPK-ERK3/mTORC1 pathways. ERK3 is a newfound potential prognostic predictor and a tumor suppressor in ICC. Electronic supplementary material The online version of this article (doi:10.1186/s13045-017-0424-0) contains supplementary material, which is available to authorized users.

Apoptotic liver cancer cells have important roles in liver tumorigenesis and liver cancer progression. Recent studies have shown that δ-opioid receptors are highly expressed in human liver and liver cancer cells. The present study aimed to investigate the role of activated δ-opioid receptors on human liver cancer cell apoptosis and its interrelation with the mitochondria and the protein kinase C/extracellular-signal-regulated kinase (PKC/ERK) signaling pathway. H2O2 was used to induce apoptosis in human liver cancer cells. During apoptosis, mitochondrial transmembrane potentials were observed to decrease, cytochrome c expression was found to increase and B cell lymphoma 2 (Bcl‑2) expression decreased. These findings suggested that H2O2-induced apoptosis was mediated through the mitochondrial pathway. Of note, activated δ-opioid receptors were observed to inhibit H2O2-induced apoptosis in human liver cancer cells. Following δ-opioid receptor activa- tion, the number of apoptotic liver cancer cells decreased, mitochondrial transmembrane potentials were restored, cytoplasmic cytochrome c and Bcl-2-associated X protein expression decreased and Bcl-2 expression increased. These data suggested that δ-opioid receptor activation inhibited mitochondria-mediated apoptosis. In addition, activation of δ-opioid receptors was observed to increase the expression of PKC and ERK in human liver cancer cells. Furthermore, upon inhibition of the PKC/ERK signaling pathway, the protective effect associated with the δ-opioid receptor on liver cancer cell apoptosis was inhibited, which was not asso- ciated with the status of δ-opioid receptor activation. These findings suggested that the PKC/ERK signaling pathway has an important role in δ-opioid receptor-mediated inhibition of apoptosis in human liver cancer cells.