Additive effect of sirolimus and anti-death receptor 5 agonistic antibody against hepatocellular carcinoma.

BACKGROUND & AIMS: Despite careful patient selection, hepatocellular carcinoma (HCC) recurs in 10-20% of cases after liver transplantation, and the use of potent adjuvant anticancer drugs would be welcome. The aim of this study was to evaluate the efficiency of a combined therapy of rapamycin (sirolimus) and anti-death receptor (DR)5 monoclonal antibody (mAb) on HCC. METHODS: We first assessed the side effects of anti-DR5 mAb administration in vivo by giving various doses of anti-DR5 mAb. Cell proliferation assays were then performed using mouse Hepa1-6 cells or human Huh7 cells to quantify the relative cell viability under various concentrations of sirolimus, anti-DR5 mAb or a combination. Next, one million Hepa1-6 cells were transplanted into C.B17-SCID-beige mice subcutaneously, and four groups were created: (1) untreated, (2) anti-DR5 mAb alone, (3) sirolimus alone and (4) anti-DR5 mAb + sirolimus. RESULTS: Anti-DR5 mAb (200 and 300 µg/day) induced liver dysfunction with partial necrosis of the liver, but 100 µg/day was well tolerated with transaminitis, but normal bilirubin and only minor histological liver damage. In vitro, anti-DR5 mAb lysed Hepa1-6 and Huh7 cells in a dose-dependent manner, and combinations of sirolimus and anti-DR5 mAb demonstrated an additive effect. In vivo studies demonstrated that tumour sizes were significantly smaller in the combined therapy group than in the monotherapy groups. CONCLUSIONS: Combining sirolimus and low-dose anti-DR5 mAb has a significant effect against HCC. This strategy represents a potential novel approach for the management of HCC.

Human cytomegalovirus infection in humanized liver chimeric mice.

AIM: Cytomegalovirus is a common viral pathogen that influences the outcome of organ transplantation. To date, there is no established method to evaluate the effects of human CMV (HCMV) treatments in vivo except for human clinical trials. In the current study, we describe the development of a mouse model that supports the in vivo propagation of HCMV. METHODS: One million viable human hepatocytes, purified from human livers, were injected into the spleens of severe combined immunodeficient/albumin linked-urokinase type plasminogen activator transgenic mice. A clinical strain of HCMV was inoculated in mice with confirmed human hepatocyte engraftment or in non-chimeric controls. Infection was monitored through HCMV titers in the plasma. Mice were administrated ganciclovir (50 mg/kg per day, i.p.) beginning at 2 days post-HCMV inoculation, or human liver natural killer (NK) cells (20 × 10(6) cells/mouse, i.v.) 1 day prior to HCMV inoculation. RESULTS: Chimeric mice that received HCMV showed high plasma titers of HCMV DNA on days 1 and 6 that became undetectable by day 11 post-inoculation. In contrast, non-transplanted mice had only residual plasma inoculum detection at day 1 and no detectable viremia thereafter. The levels of HCMV DNA were reduced by ganciclovir treatment or by human liver NK cell adoptive transfer, while HCMV-infected chimeric mice that were not treated sustained viremia during the follow up. CONCLUSION: Human liver chimeric mice provide an in vivo model for the study of acute HCMV infection of hepatocytes.

Factors predicting survival after post-transplant hepatocellular carcinoma recurrence.

BACKGROUND: Although factors associated with an increased risk of recurrence after liver transplantation for hepatocellular carcinoma (HCC) have been extensively studied, the history of patients with a post-transplant recurrence is poorly known. METHODS: Patients experiencing a post-transplant HCC recurrence from 1996 to 2011 in two transplant programs were included. Demographic, transplant, and post-recurrence variables were assessed. RESULTS: Thirty patients experienced an HCC recurrence-22 men and 8 women with a mean age of 55 ± 6 years. Sixteen (53 %) were outside the Milan criteria at the time of transplantation. Most recurrences (60 %) appeared within the first 18 months after transplantation, ranging between 1.7 and 109 months (median 14.2 months). Mean post-recurrence survival was 33 ± 31 months. On univariate analysis, total tumor volume (TTV; p = 0.047), microvascular invasion (p = 0.011), and time from transplant to recurrence (p = 0.001) predicted post-recurrence survival. On multivariate analysis, both time from transplant to recurrence (p = 0.001) and history of rejection (p = 0.043), but not the location of the recurrence or the type of recurrence treatment, predicted post-recurrence survival. CONCLUSION: This study suggests that patients with early post-transplant HCC recurrence have worse outcomes. Those with a history of graft rejection have better survivals, possibly due to more active anti-cancer immunity.