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Chemoresistance is the main cause of chemotherapy failure in patients with hepatocellular carcinoma (HCC). The gene encoding transmembrane protein 47 (TMEM47) was previously identified to be significantly upregulated in HCC cell lines with acquired chemoresistance. The aim of the present study was to characterize the clinical significance and function of TMEM47 in HCC chemoresistance. The results demonstrated that the TMEM47 expression levels in the tumors of patients not responding to cisplatin‑based transarterial chemoembolization (TACE) treatment was significantly higher compared with those in patients who responded to TACE treatment. Moreover, analyses from clinical samples and HCC cell lines indicated that TMEM47 expression may be upregulated in HCC in response to cisplatin treatment. Furthermore, the TMEM47 mRNA expression levels were positively correlated with the degree of cisplatin resistance of HCC cells. Overexpression of TMEM47 in HCC cells significantly promoted cisplatin resistance. The present study also demonstrated that targeted inhibition of TMEM47 could significantly reduce cisplatin resistance of cisplatin‑resistant HCC cells via enhancing caspase‑mediated apoptosis. In addition, targeted inhibition of TMEM47 enhanced the sensitivity of cisplatin‑resistant cells to cisplatin via suppressing cisplatin‑induced activation of the genes involved in drug efflux and metabolism. The present study also validated that TMEM47 expression was significantly correlated with multidrug resistance‑associated protein 1 in patients with HCC who received TACE treatment. In conclusion, the findings of the present study demonstrated that TMEM47 may be a useful biomarker for predicting the response to chemotherapy and a potential therapeutic target for overcoming HCC chemoresistance.

Background and Aims: Our previous study showed that small-for-size liver graft may provide favorable micro-environment for tumor growth. GPx3, an anti-oxidant, not only attenuates oxidative stress, but also suppresses liver tumor growth in our recent study. Here, we aimed to characterize the clinical significance and explore the functional role of GPx3 in HCC recurrence after liver transplantation., Methods: To explore the association between GPx3 expression and HCC invasiveness, a rat orthotopic liver transplantation model with tumor development was established. To investigate the clinical relevance of GPx3, 105 HCC patients who underwent liver transplantation were recruited. The suppressive role of GPx3 in HCC cells was studied using wound healing, Matrigel invasion assay and lung metastasis model. The real-time intravital imaging system was applied to directly visualize the tumor cells invasion in a living animal. The underlying mechanism was further explored., Results: GPx3 was identified as a down-regulated protein in small-for-size liver graft and significantly associated with invasive phenotype of tumor growth in a rat model. Plasma GPx3 was significantly lower in small-for-size graft group post-transplantation (day1: 33 vs 1147; day3: 3209 vs 4459; day7: 303 vs 2506; mU/mL, P<0.05) in rat model. Clinically, the plasma GPx3 was significantly lower in the recipients with HCC recurrence post-transplantation (day1: 4.16 vs 8.99 µg/mL, P<0.001; day7: 3.86 vs 9.99 µg/mL, P<0.001). Furthermore, lower plasma GPx3 was identified as an independent predictor (HR=4.528, P=0.046) for poor overall survival post-transplantation. Over-expression of GPx3 significantly suppressed migration, invasiveness and metastasis of HCC cells. Real-time intravital imaging showed that GPx3 significantly suppressed HCC invasiveness in a live animal. GPx3 suppressed the tumor invasiveness through inhibition of JNK-cJun-MMP2 pathway., Conclusion: GPx3 may possess prognostic and therapeutic value for HCC patients after liver transplantation., Competing Interests: The authors have declared that no competing interest exists.

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.

Tumor recurrence remains an obstacle after liver surgery, especially in living donor liver transplantation (LDLT) for patients with hepatocellular carcinoma (HCC). The acute-phase liver graft injury might potentially induce poor response to chemotherapy in recurrent HCC after liver transplantation. We here intended to explore the mechanism and to identify a therapeutic target to overcome such chemoresistance. The associations among graft injury, overexpression of IP10 and multidrug resistant genes were investigated in a rat liver transplantation model, and further validated in clinical cohort. The role of IP10 on HCC cell proliferation and tumor growth under chemotherapy was studied both in vitro and in vivo. The underlying mechanism was revealed by detecting the activation of endoplasmic reticulum (ER) stress signaling pathways. Moreover, the effect of IP10 neutralizing antibody sensitizing cisplatin treatment was further explored. In rat liver transplantation model, significant up-regulation of IP10 associated with multidrug resistant genes was found in small-for-size liver graft. Clinically, high expression of circulating IP10 was significant correlated with tumor recurrence in HCC patients underwent LDLT. Overexpression of IP10 promoted HCC cell proliferation and tumor growth under cisplatin treatment by activation of ATF6/Grp78 signaling. IP10 neutralizing antibody sensitized cisplatin treatment in nude mice. The overexpression of IP10, which induced by liver graft injury, may lead to cisplatin resistance via ATF6/Grp78 ER stress signaling pathway. IP10 neutralizing antibody could be a potential adjuvant therapy to sensitize cisplatin treatment.

Human hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide with a poor prognosis of limited survival. The role of regulatory B cell (Breg), a new important B cell subset, in HCC progression remains unclear. We firstly found that the percentage of B cells at tumor margin was significantly higher than that in tumor and non-tumor regions. Especially, increased intrahepatic B cells at tumor margin were positively associated with tumor invasive features and more tumor recurrence. Besides, HCC patients had a significantly higher percentage of circulating Bregs than healthy people. Increased circulating Bregs were correlated with advanced tumor staging, tumor multiplicity and venous infiltration. Next, we firstly revealed that human Bregs promoted HCC tumor growth independent of Tregs in SCID mice. The migration of Bregs from blood into tumor was also confirmed in mice. Finally, we further explored the molecular mechanism of Bregs promoting proliferation and migration of HCC cells in vitro. Bregs promoted HCC growth and invasiveness by directly interacting with liver cancer cells through the CD40/CD154 signaling pathway., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

Aims: We aimed to investigate the clinical significance of GPx3 in hepatocellular carcinoma (HCC) and to characterize its tumor suppressive role., Methods: HCC patients (113) who underwent hepatectomy were recruited to examine the clinical relevance of GPx3. The tumor suppressive role of GPx3 was studied by administration of recombinant GPx3 (rGPx3) or over-expression of GPx3 in HCC cells in vitro and in vivo. The therapeutic value of GPx3 for HCC was further investigated using human induced pluripotent stem cell derived mesenchymal stem cells (hiPSC-MSCs) as its delivery vehicle., Results: Down-regulation of GPx3 significantly correlated with advanced tumor stage (P = 0.024), venous infiltration (P = 0.043) and poor overall survival (P = 0.007) after hepatectomy. Lower plasma GPx3 in HCC patients was significantly associated with larger tumor size (P = 0.011), more tumor nodules (P = 0.032) and higher recurrence (P = 0.016). Over-expression of GPx3 or administration of rGPx3 significantly inhibited proliferation and invasiveness of HCC cells in vitro and in vivo. Tumor suppressive activity of GPx3 was mediated through Erk-NFκB-SIP1 pathway. GPx3 could be delivered by hiPSC-MSCs into the tumor and exhibited tumor suppressive activity in vivo., Conclusions: GPx3 is a tumor suppressor gene in HCC and may possess prognostic and therapeutic value for HCC patients.

Chemoresistance is one of the major obstacles in systemic chemotherapy and targeted therapy for patients with advanced hepatocellular carcinoma. To identify novel chemoresistance-associated targets in hepatocellular carcinoma, chemoresistant hepatocellular carcinoma cell lines were established. By comparing the global gene expression profiles between chemoresistant and chemosensitive cell lines, eight novel chemoresistance-associated genes were identified to be significantly associated with the commonly augmented chemoresistance of hepatocellular carcinoma cells. One upregulated candidate named transmembrane protein 98 (TMEM98) was found to be overexpressed in 80 of 118 (67.80%) of patients with hepatocellular carcinoma. TMEM98 mRNA in tumor tissues was significantly higher than nontumor tissues of patients with hepatocellular carcinoma (P < 0.0001). Upregulation of TMEM98 was significantly correlated with advanced tumor stage (P = 0.048), high incidence of early tumor recurrence (P = 0.005), poor overall survival (P = 0.029), and poor disease-free survival (P = 0.011) of patients with hepatocellular carcinoma after hepatectomy. Importantly, upregulation of TMEM98 mRNA in patients with hepatocellular carcinoma who received transarterial chemoembolization (TACE) treatment was significantly higher than in patients without TACE treatment (P = 0.046). Moreover, patients with poor response to TACE treatment had higher degree of TMEM98 upregulation than the responsive patients. In vitro and in vivo studies showed that suppression of TMEM98 in chemoresistant hepatocellular carcinoma cells restored their chemosensitivity, while forced overexpression of TMEM98 enhanced their chemoresistance. The mechanism of TMEM98 in conferring chemoresistance of hepatocellular carcinoma might be possibly through activation of the AKT pathway and deactivation of p53. In conclusion, we identified a panel of novel common chemoresistance-associated genes and demonstrated that TMEM98 is a chemoresistance-conferring gene in hepatocellular carcinoma.

Background: Surgical therapies are the first-line treatments for hepatocellular carcinoma (HCC) patients. However, the high incidence of tumor metastasis after liver surgery remains a severe problem. We aim to investigate the roles and the underlying mechanism of YQ23, stabilized non-polymeric diaspirin cross-linked tetrameric hemoglobin, in liver tumor metastasis after major hepatectomy and partial hepatic ischemia reperfusion (I/R) injury., Methods: An orthotopic liver tumor model in Buffalo rat was established using the hepatocellular carcinoma cell line McA-RH7777. Major hepatectomy for tumor-bearing lobe and partial hepatic I/R injury were performed at two weeks after orthotopic liver tumor implantation. YQ23 (0.2 g/kg) was administered at 1 hour before ischemia and immediately after reperfusion. Blood samples were collected at day 0, 1, 7, 14, 21 and 28 for detection of circulating endothelial progenitor cells (EPCs) and regulatory T cells (Tregs)., Results: Our results showed that YQ23 treatment effectively inhibited intrahepatic and lung metastases together with less tumor angiogenesis at 4 weeks after major hepatectomy and partial hepatic I/R injury. The levels of circulating EPCs and Tregs were significantly decreased in YQ23 treatment group. Furthermore, YQ23 treatment also increased liver tissue oxygenation during hepatic I/R injury. Up-regulation of HO1 and down-regulation of CXCR3, TNF-α and IL6 were detected after YQ23 treatment., Conclusions: YQ23 treatment suppressed liver tumor metastasis after major hepatectomy and partial hepatic I/R injury in a rat liver tumor model through increasing liver oxygen and reducing the populations of circulating EPCs and Tregs.

Background: Surgical procedures such as liver resection and liver transplantation are the first-line treatments for hepatocellular carcinoma (HCC) patients. However, the high incidence of tumor recurrence and metastasis after liver surgery remains a major problem. Recent studies have shown that hepatic ischemia-reperfusion (I/R) injury and endothelial progenitor cells (EPCs) contribute to tumor growth and metastasis. We aim to investigate the mechanism of FTY720, which was originally applied as an immunomodulator, on suppression of liver tumor metastasis after liver resection and partial hepatic I/R injury., Methodology/principal Findings: An orthotopic liver tumor model in Buffalo rat was established using the hepatocellular carcinoma cell line McA-RH7777. Two weeks after orthotopic liver tumor implantation, the rats underwent liver resection for tumor-bearing lobe and partial hepatic I/R injury. FTY720 (2 mg/kg) was administered through the inferior caval vein before and after I/R injury. Blood samples were taken at days 0, 1, 3, 7, 14, 21 and 28 for detection of circulating EPCs (CD133+CD34+). Our results showed that intrahepatic and lung metastases were significantly inhibited together with less tumor angiogenesis by FTY720 treatment. The number of circulating EPCs was also significantly decreased by FTY720 treatment from day 7 to day 28. Hepatic gene expressions of CXCL10, VEGF, CXCR3, CXCR4 induced by hepatic I/R injury were down-regulated in the treatment group., Conclusions/significance: FTY720 suppressed liver tumor metastasis after liver resection marred by hepatic I/R injury in a rat liver tumor model by attenuating hepatic I/R injury and reducing circulating EPCs.

Background: Hepatocellular carcinoma (HCC) is highly malignant and metastatic. Currently, there is no effective chemotherapy for patients with advanced HCC leading to an urgent need to seek for novel therapeutic options. We aimed to investigate the effect of a garlic derivative, S-allylcysteine (SAC), on the proliferation and metastasis of HCC., Methodology/principal Findings: A series of in vitro experiments including MTT, colony-forming, wound-healing, invasion, apoptosis and cell cycle assays were performed to examine the anti-proliferative and anti-metastatic effects of SAC on a metastatic HCC cell line MHCC97L. The therapeutic values of SAC single and combined with cisplatin treatments were examined in an in vivo orthotopic xenograft liver tumor model. The result showed that the proliferation rate and colony-forming abilities of MHCC97L cells were suppressed by SAC together with significant suppression of the expressions of proliferation markers, Ki-67 and proliferating cell nuclear antigen (PCNA). Moreover, SAC hindered the migration and invasion of MHCC97L cells corresponding with up-regulation of E-cadherin and down-regulation of VEGF. Furthermore, SAC significantly induced apoptosis and necrosis of MHCC97L cells through suppressing Bcl-xL and Bcl-2 as well as activating caspase-3 and caspase-9. In addition, SAC could significantly induce the S phase arrest of MHCC97L cells together with down-regulation of cdc25c, cdc2 and cyclin B1. In vivo xenograft liver tumor model demonstrated that SAC single or combined with cisplatin treatment inhibited the progression and metastasis of HCC tumor., Conclusions/significance: Our data demonstrate the anti-proliferative and anti-metastatic effects of SAC on HCC cells and suggest that SAC may be a potential therapeutic agent for the treatment of HCC patients.