The number of hepatocellular carcinoma foci as predictor of poor response to tumor-directed therapies in patients awaiting liver transplantation: a prospective cohort study.

BACKGROUND AND AIMS: Tumor-directed therapies (TDTs) are a constitutive part of hepatocellular carcinoma (HCC) treatment in patients awaiting liver transplantation (LT). While most patients benefit from TDTs as a bridge to LT, some patients drop out from the waiting list due to tumor progression. The study aimed to determine the risk factors for poor treatment outcome following TDTs among patients with HCC awaiting LT. METHODS: A total of 123 patients with HCC were evaluated with 92 patients meeting Milan Criteria enrolled in the prospective cohort study. Tumor response was evaluated using the modified Response Evaluation Criteria for Solid Tumors for HCC 1 month after the procedure. The risk factors for progressive disease (PD) and dropout were evaluated. RESULTS: After TDT, 55 patients (59.8%) achieved complete or partial response (44.6% and 15.2% respectively), 17 patients (18.5%) had stable disease, and 20 patients (21.7%) were assessed as PD. Multivariate analysis revealed a significant and independent association between the number of HCC foci and PD ( P  = 0.03, OR = 2.68). There was no statistically significant association between treatment response and demographics, MELDNa score, pre-and post-treatment alpha-fetoprotein (AFP), cumulative tumor burden the largest tumor size, or TDT modality. PD was the major cause of dropout in our cohort. Pre-treatment AFP levels ≥200 ng/ml had a strong association with dropout after TDTs ( P  = 0.0005). CONCLUSION: This study demonstrated the presence of multifocal HCC is the sole prognostic factor for PD following TDTs in HCC patients awaiting LT. We recommend prioritizing patients with multifocal HCC within Milan criteria by exception points for LT to improve the dropout rate.

Interferon-alpha-induced hepatitis C virus clearance restores p53 tumor suppressor more than direct-acting antivirals.

The mechanism why hepatitis C virus (HCV) clearance by direct-acting antivirals (DAAs) does not eliminate the risk of hepatocellular carcinoma (HCC) among patients with advanced cirrhosis is unclear. Many viral and bacterial infections degrade p53 in favor of cell survival to adapt an endoplasmic reticulum (ER)-stress response. In this study, we examined whether HCV clearance by interferon-alpha or DAAs normalizes the ER stress and restores the expression of p53 tumor suppressor in cell culture. We found that HCV infection induces chronic ER stress and unfolded protein response in untransformed primary human hepatocytes. The unfolded protein response induces chaperone-mediated autophagy (CMA) in infected primary human hepatocytes and Huh-7.5 cells that results in degradation of p53 and induced expression of mouse double minute 2 (Mdm2). Inhibition of p53/Mdm2 interactions by small molecule (nutlin-3) or silencing Mdm2 did not rescue the p53 degradation, indicating that HCV infection induces degradation of p53 independent of the Mdm2 pathway. Interestingly, we found that HCV infection degrades p53 in a lysosome-dependent mechanism because lysosome-associated membrane protein 2A silencing restored p53 degradation. Our results show that HCV clearance induced by interferon-alpha-based antiviral therapies normalizes the ER-stress response and restores p53, whereas HCV clearance by DAAs does neither. We show that decreased expression of p53 in HCV-infected cirrhotic liver is associated with expression of chaperones associated with ER stress and the CMA response. Conclusion: HCV-induced ER stress and CMA promote p53 degradation in advanced liver cirrhosis. HCV clearance by DAAs does not restore p53, which provides a potential explanation for why a viral cure by DAAs does not eliminate the HCC risk among patients with advanced liver disease. We propose that resolving the ER-stress response is an alternative approach to reducing HCC risk among patients with cirrhosis after viral cure. (Hepatology Communications 2017;1:256-269).

Reduced expression of Jak-1 and Tyk-2 proteins leads to interferon resistance in hepatitis C virus replicon.

BACKGROUND: Alpha interferon in combination with ribavirin is the standard therapy for hepatitis C virus infection. Unfortunately, a significant number of patients fail to eradicate their infection with this regimen. The mechanisms of IFN-resistance are unclear. The aim of this study was to determine the contribution of host cell factors to the mechanisms of interferon resistance using replicon cell lines. RESULTS: HCV replicons with high and low activation of the IFN-promoter were cultured for a prolonged period of time in the presence of interferon-alpha (IFN-alpha2b). Stable replicon cell lines with resistant phenotype were isolated and characterized by their ability to continue viral replication in the presence of IFN-alpha. Interferon resistant cell colonies developed only in replicons having lower activation of the IFN promoter and no resistant colonies arose from replicons that exhibit higher activation of the IFN promoter. Individual cell clones were isolated and nine IFN resistant cell lines were established. HCV RNA and protein levels in these cells were not altered by IFN- alpha2b. Reduced signaling and IFN-resistant phenotype was found in all Huh-7 cell lines even after eliminating HCV, suggesting that cellular factors are involved. Resistant phenotype in the replicons is not due to lack of interferon receptor expression. All the cell lines show defect in the JAK-STAT signaling and phosphorylation of STAT 1 and STAT 2 proteins were strongly inhibited due to reduced expression of Tyk2 and Jak-1 protein. CONCLUSION: This in vitro study provides evidence that altered expression of the Jak-Stat signaling proteins can cause IFN resistance using HCV replicon cell clones.