Oncoprotein Stathmin Modulates Sensitivity to Apoptosis in Hepatocellular Carcinoma Cells During Hepatitis C Viral Replication.

Patients with chronic hepatitis C virus (HCV) infection risk complications of cirrhosis, liver failure, and hepatocellular carcinoma (HCC). Previously, our proteomic examination of hepatocytes carrying a HCV-replicon revealed that deregulation of cytoskeletal dynamics may be a potential mechanism of viral-induced HCC growth. Here, we demonstrate the effect of HCV replication on the microtubule regulator stathmin (STMN1) in HCC cells. We further explore how the altered activity or synthesis of stathmin affects cellular proliferation and sensitivity to apoptosis in control HCC cells (Huh7.5) and experimental HCV-replicon harboring HCC cells (R-Huh7.5). The HCV-replicon harboring HCC cells (R-Huh 7.5) lack viral structural genes/proteins for acute infectivity and thus is the standard model for in vitro chronic infection study. Knockdown of endogenous stathmin reduced sensitivity to apoptosis in replicon cells. Meanwhile, constitutively active stathmin increased sensitivity to apoptosis in replicon cells. In addition, overexpression of constitutively active stathmin reduced cell proliferation in both control and replicon cells. These findings implicate, for the first time, a novel role for stathmin in viral replication-related apoptosis. Stathmin's potential role in HCV replication and HCC make it a candidate for the future study of viral-induced malignancies.

Phospho-Network Analysis Identifies and Quantifies Hepatitis C Virus (HCV)-induced Hepatocellular Carcinoma (HCC) Proteins Regulating Viral-mediated Tumor Growth.

BACKGROUND: Patients with chronic hepatitis C virus (HCV) infection are at risk of serious complications of cirrhosis and hepatocellular carcinoma (HCC). Mass spectrometry (MS) is a versatile methodology that produces a global proteomic landscape for analysis of cancer mechanisms. MATERIALS AND METHODS: Using multiplex peptide stable isotopic labeling and immobilized metal affinity chromatography (IMAC), we enriched and quantified the phosphoproteome of HCC, with and without HCV. While raw data identified protein targets based on expression alone, we also used abundance groups for comprehensive functional analysis. RESULTS: Analysis of functional differences highlighted deregulated phosphoprotein networks. This uncovered additional candidates that could be directly derived from the MS data. Cellular processes and pathways that may differ with HCV infection include: cytoskeletal dynamics, insulin response, gene expression, and PI3K/AKT oncogenesis. CONCLUSION: This function-focused workflow provides a simple framework to analyze MS data. Phosphoproteome quantitation with inclusive functional analysis can generate hypotheses for liver cancer research to improve early screening and identification of molecular targets for therapy.

A Phase I Dose Escalation Study Demonstrates Quercetin Safety and Explores Potential for Bioflavonoid Antivirals in Patients with Chronic Hepatitis C.

The hepatitis C virus (HCV) infects more than 180 million people worldwide, with long-term consequences including liver failure and hepatocellular carcinoma. Quercetin bioflavonoids can decrease HCV production in tissue culture, in part through inhibition of heat shock proteins. If quercetin demonstrates safety and antiviral activity in patients, then it could be developed into an inexpensive HCV treatment for third world countries or other affected populations that lack financial means to cover the cost of mainstream antivirals. A phase 1 dose escalation study was performed to evaluate the safety of quercetin in 30 untreated patients with chronic HCV infection and to preliminarily characterize quercetin's potential in suppressing viral load and/or liver injury. Quercetin displayed safety in all trial participants. Additionally, 8 patients showed a "clinically meaningful" 0.41-log viral load decrease. There was a positive correlation (r = 0.41, p = 0.03) indicating a tendency for HCV decrease in patients with a lower ratio of plasma quercetin relative to dose. No significant changes in aspartate transaminase and alanine transaminase were detected. In conclusion, quercetin exhibited safety (up to 5 g daily) and there was a potential for antiviral activity in some hepatitis C patients.

Intrathecal trastuzumab: immunotherapy improves the prognosis of leptomeningeal metastases in HER-2+ breast cancer patient.

We describe the clinical and therapeutic course of a 51-year-old woman with HER-2+ breast cancer who developed leptomeningeal (LM) and spinal cord metastases after 8 years of stable disease on combination therapy with intravenous (IV) trastuzumab. Due to progressive CNS disease, intrathecal (IT) trastuzumab was introduced to enhance HER-2+ therapy into the CSF space. A combination HER-2+ targeted approach achieved clinical remission with stable disease in our patient 46 months after she was diagnosed with LM metastases. However, spinal cord C-1 metastasis was not fully controlled with IT trastuzumab, ultimately leading to the patient's respiratory compromise. In our patient, IT trastuzumab immunotherapy improved prognosis and was an effective strategy to manage HER-2+ LM disease. Given alone or alongside other anti-HER-2+ therapeutics with sufficient CNS penetration, IT trastuzumab could extend the lifespan of patients with leptomeningeal and CNS metastases.