Di Lu

Liver transplantation for hepatocellular carcinoma beyond the Milan criteria

Objective Liver transplantation is an optimal radical therapy for selected patients with hepatocellular carcinoma. The stringent organ allocation system driven by the Milan criteria has been challenged by alternative sets of expanded criteria. Careful analysis is needed to prove that the Milan criteria can be expanded safely and effectively. Design This study collectively reviewed 6012 patients of hepatocellular carcinoma from the China Liver Transplant Registry. Expanded criteria were evaluated to characterise an optimised expansion with acceptable outcomes beyond the Milan criteria. Results Compared with the Milan criteria, Valencia, University of California, San Francisco, University Clinic of Navarra and Hangzhou criteria provided an expansion of 12.4%, 16.3%, 19.6%, and 51.5%, respectively. The post-transplant survivals of patients fulfilling the expanded criteria were comparable to that of the Milan criteria. The analysis of net reclassification improvement and area under the receiver operating characteristic curves showed an excellent efficiency in recurrence prediction for the expanded criteria compared with the Milan criteria. In patients exceeding Milan but fulfilling the Hangzhou criteria (N=1352), α-fetoprotein (AFP) >100 ng/mL and tumour burden>8 cm were the only two independent prognostic factors (p<0.001). Accordingly, the Hangzhou criteria were stratified as type A (tumour burden ≤8 cm, or tumour burden >8 cm but AFP≤100 ng/mL) and type B (tumour burden >8 cm but AFP between 100 and 400 ng/mL). Type A showed significantly higher 5-year tumour-free survival rates compared with type B (p<0.001). Conclusions The Milan criteria can be expanded safely and effectively. The prognostic stratification system based on the Hangzhou criteria serves as a hierarchy of transplant candidates for hepatocellular carcinoma.

Association between donor and recipient TCF7L2 gene polymorphisms and the risk of new-onset diabetes mellitus after liver transplantation in a Han Chinese population

BACKGROUNDS & AIMS New-onset diabetes mellitus (NODM) is a frequent and serious complication arising after liver transplantation (LT). Transcription factor 7-like 2 (TCF7L2) polymorphisms have been reported to strongly associate with type 2 diabetes. In addition, the donor liver plays a vital role in regulating blood glucose levels. In this study, we aim at evaluating the association between donor and recipient TCF7L2 gene polymorphisms with NODM after LT. METHODS A total of 125 patients undergoing primary LT, without a history of diabetes were included. Four single nucleotide polymorphisms (rs290487, rs7903146, rs11196205, and rs12255372), closely associated with type 2 diabetes in the Eastern Asia population, were genotyped and analyzed. RESULTS Both donor and recipient rs290487 polymorphisms (CC vs. TT genotype) were found to be significantly associated with NODM. In multivariate analysis, donor rs290487 genetic variation (OR = 2.172 per each C allele, p = 0.015), blood tacrolimus levels at 1 month post-LT >10 ng/ml (OR = 3.264, p = 0.017), and recipient age >55 years (OR = 2.638, p = 0.043) were identified as independent risk factors of NODM. Furthermore, donor rs290487 CC genotype could predict a high probability (>40%) of the onset of NODM. Predictive model containing donor rs290487 polymorphism showed a significantly higher prognostic ability on NODM than the model with only clinical parameters (p = 0.031). CONCLUSIONS Donor TCF7L2 rs290487 polymorphism is associated with an increased risk of NODM after LT and has a potential clinical value for the prediction of NODM.

Donor miR-196a-2 polymorphism is associated with hepatocellular carcinoma recurrence after liver transplantation in a Han Chinese population.

Recurrence of hepatocellular carcinoma (HCC) is one of the leading causes of death after liver transplantation (LT). We aim to evaluate the association of donor and recipient single nucleotide polymorphisms (SNPs) with the risk of HCC recurrence after LT. A total of 155 adult patients who underwent primary LT for HCC were enrolled. Ten SNPs associated with HCC susceptibility were genotyped. Patients who received donor livers with the rs11614913 homozygous CC variant presented significantly higher recurrence rates of HCC (41.7 vs. 15.3%, p = 0.009) and lower cumulative tumor‐free survival (p = 0.005) than those who received TT wild‐type donor livers. The donor rs11614913 genetic variant was an independent risk factor for HCC recurrence (odds ratio = 2 per each C allele, p < 0.05) and could significantly improve the predictive abilities of clinical models (Milan, UCSF and Hangzhou criteria). Donor livers homozygous for rs11614913 CC were associated with a higher miR‐196a expression than TT (p = 0.002). In a lentiviral infection of mouse liver and orthotopic mouse model of HCC, the liver miR‐196a overexpression group showed a significantly larger tumor size than the control group (p = 0.001). There is a close association between the tumor size and expression of miR‐196a in the liver (r = 0.693, p = 0.001). In conclusion, the donor miR‐196a‐2 rs11614913 polymorphism is associated with HCC recurrence after LT and improves the predictive value of clinical models. The overexpression of miR‐196a in the liver might provide a tumor‐favorable environment for the development of HCC.

Major influence of renal function on hyperlipidemia after living donor liver transplantation

AIM To investigate the impact of renal and graft function on post-transplant hyperlipidemia (PTHL) in living donor liver transplantation (LDLT). METHODS A total of 115 adult patients undergoing LDLT from January 2007 to May 2009 at a single center were enrolled. Data were collected and analyzed by the China Liver Transplant Registry retrospectively. PTHL was defined as serum triglycerides ≥ 150 mg/dL or serum cholesterol ≥ 200 mg/dL or the need for pharmacologic treatment at the sixth month after LDLT. Early renal dysfunction (ERD) was defined as serum creatinine ≥ 2 mg/dL and/or the need for renal replacement therapy in the first post-transplant week. RESULTS In 115 eligible patients, the incidence of PTHL was 24.3%. Recipients with PTHL showed a higher incidence of post-transplant cardiovascular events compared to those without PTHL (17.9% vs 4.6%, P = 0.037). Serum creatinine showed significant positive correlations with total serum triglycerides, both at post-transplant month 1 and 3 (P < 0.01). Patients with ERD had much higher pre-transplant serum creatinine levels (P < 0.001) and longer duration of pre-transplant renal insufficiency (P < 0.001) than those without ERD. Pre-transplant serum creatinine, graft-to-recipient weight ratio, graft volume/standard liver volume ratio, body mass index (BMI) and ERD were identified as risk factors for PTHL by univariate analysis. Furthermore, ERD [odds ratio (OR) = 9.593, P < 0.001] and BMI (OR = 6.358, P = 0.002) were identified as independent risk factors for PTHL by multivariate analysis. CONCLUSION Renal function is closely associated with the development of PTHL in LDLT. Post-transplant renal dysfunction, which mainly results from pre-transplant renal insufficiency, contributes to PTHL.

USP22 mediates the multidrug resistance of hepatocellular carcinoma via the SIRT1/AKT/MRP1 signaling pathway

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.

The phospholipase A2 activity of peroxiredoxin 6 promotes cancer cell death induced by tumor necrosis factor alpha in hepatocellular carcinoma.

In this study, we used proteomic profiling to compare hepatocellular carcinoma (HCC) and peri‐tumoral tissues to identify potential tumor markers of HCC. We identified eight differentially expressed proteins (>3‐fold), including Peroxiredoxin 6 (PRDX6). PRDX6 is a bifunctional enzyme with both peroxidase and calcium‐independent phospholipase A2 (iPLA2) activity. We found that peri‐tumoral tissues expressed higher levels of PRDX6 mRNA (n = 59, P = 0.018) and protein (n = 265, P < 0.001) than HCC tissues, and that decreased expression of PRDX6 in HCC tissues was an independent risk factor indicating a poor prognosis (n = 145, P = 0.007). Combining the examination of serum PRDX6 with α‐fetoprotein improved the diagnostic sensitivity of tests for HCC compared to α‐fetoprotein alone (85.0% vs 50.0%, n = 40). We found that PRDX6 induced S phase arrest in HCC cells and inhibited HCC tumorigenicity in mice injected with cancer cells. When treated with H2O2, PRDX6 inhibited apoptosis. When treated with tumor necrosis factor alpha (TNF‐α), PRDX6 promoted apoptosis. Inhibition of iPLA2 activity of PRDX6 decreased the apoptosis induced by TNF‐α. In conclusion, PRDX6 inhibited the carcinogenesis of HCC, and the iPLA2 activity of PRDX6 promoted cancer cell death induced by TNF‐α.

LEPREL1 Expression in Human Hepatocellular Carcinoma and Its Suppressor Role on Cell Proliferation.

Background. Hepatocellular carcinoma (HCC) is one of the most aggressive malignancies worldwide. It is characterized by its high invasive and metastatic potential. Leprecan-like 1 (LEPREL1) has been demonstrated to be downregulated in the HCC tissues in previous proteomics studies. The present study is aimed at a new understanding of LEPREL1 function in HCC. Methods. Quantitative RT-PCR, immunohistochemical analysis, and western blot analysis were used to evaluate the expression of LEPREL1 between the paired HCC tumor and nontumorous tissues. The biology function of LEPREL1 was investigated by Cell Counting Kit-8 (CCK8) assay and colony formation assay in HepG2 and Bel-7402 cells. Results. The levels of LEPREL1 mRNA and protein were significantly lower in the HCC tissues as compared to those of the nontumorous tissues. Reduced LEPREL1 expression was not associated with conventional clinical parameters of HCC. Overexpression of LEPREL1 in HepG2 and Bel-7402 cells inhibited cell proliferation (P < 0.01) and colony formation (P < 0.05). LEPREL1 suppressed tumor cell proliferation through regulation of the cell cycle by downregulation of cyclins. Conclusions. Clinical parameters analysis suggested that LEPREL1 was an independent factor in the development of HCC. The biology function experiments showed that LEPREL1 might serve as a potential tumor suppressor gene by inhibiting the HCC cell proliferation.

Chloride intracellular channel 1 participates in migration and invasion of hepatocellular carcinoma by targeting maspin

Our previous proteomic research found that chloride intracellular channel 1 (CLIC1) was upregulated in hepatocellular carcinoma (HCC) tissues with portal vein tumor thrombus. The present study aimed to determine the role of CLIC1 in HCC invasion.

Proteomics-based identification of the tumor suppressor role of aminoacylase 1 in hepatocellular carcinoma

The present work aimed to investigate the expression and role of aminoacylase 1 (ACY1) in hepatocellular carcinoma (HCC) based on a proteomic study. The study results revealed that the expression of ACY1 was much lower in HCC tissues. ACY1 expression significantly correlated with the serum alpha fetoprotein level and tumor invasiveness. The knockdown of ACY1 in SMMC7721 cells promoted cell viability and invasiveness. In contrast, the restoration of ACY1 in BEL7402 cells inhibited cell viability and invasiveness. Further studies indicated that the knockdown of ACY1 increased the protein expression of transforming growth factor beta 1 and extracellular signal-regulated kinase 1 expression. The studys results indicated that ACY1 acts as a tumor suppressor in HCC.

Peroxiredoxins in inflammatory liver diseases and ischemic/reperfusion injury in liver transplantation

Peroxiredoxins (Prxs) belong to the superfamily of thiol-dependent peroxidases, and remove reactive oxygen species (ROS) and other oxidative stress products. The expression and activity of Prxs can be substantially affected by stimuli from the microenvironment, and in turn regulate cytokine secretion in the context of inflammation in both peroxidase-dependent and -independent pathways. Prxs translocate to mitochondria and are hyperoxidized during acute liver damage, and attenuate intracellular ROS accumulation through their peroxidase activity. In particularly, Prx1 modulates the microenvironment in liver injuries by reducing adhesion molecule expression in vascular endothelial cells and inhibiting the inflammatory response and adhesion of macrophages. Prxs have potent prosurvival effects against ROS in ischemic/reperfusion (I/R) injury, but Prxs released from necrotic cells increase secretion of inflammatory cytokines by macrophages through TLR2 and 4 activation, which promotes cell death. Prxs can be used as biomarkers to evaluate I/R injury and predict graft survival in liver transplantation. Prxs are modulated in various types of chronic hepatitis and hepatosteatosis, and mediate disease progression. Alcohol administration increases oxidization and inactivation of Prxs in mice because of oxidative stress. In conclusion, Prxs are essential mediators and biomarkers in inflammatory liver diseases and I/R injury.