Unlocking the Potential of Arginine Deprivation Therapy: Recent Breakthroughs and Promising Future for Cancer Treatment.

Arginine is a semi-essential amino acid that supports protein synthesis to maintain cellular functions. Recent studies suggest that arginine also promotes wound healing, cell division, ammonia metabolism, immune system regulation, and hormone biosynthesis-all of which are critical for tumor growth. These discoveries, coupled with the understanding of cancer cell metabolic reprogramming, have led to renewed interest in arginine deprivation as a new anticancer therapy. Several arginine deprivation strategies have been developed and entered clinical trials. The main principle behind these therapies is that arginine auxotrophic tumors rely on external arginine sources for growth because they carry reduced key arginine-synthesizing enzymes such as argininosuccinate synthase 1 (ASS1) in the intracellular arginine cycle. To obtain anticancer effects, modified arginine-degrading enzymes, such as PEGylated recombinant human arginase 1 (rhArg1-PEG) and arginine deiminase (ADI-PEG 20), have been developed and shown to be safe and effective in clinical trials. They have been tried as a monotherapy or in combination with other existing therapies. This review discusses recent advances in arginine deprivation therapy, including the molecular basis of extracellular arginine degradation leading to tumor cell death, and how this approach could be a valuable addition to the current anticancer arsenal.

Peginterferon Is Superior to Nucleos(t)ide Analogues for Prevention of Hepatocellular Carcinoma in Chronic Hepatitis B.

BACKGROUND: Clinical factors associated with hepatocellular carcinoma (HCC) have been extensively studied in antiviral treatment-naive patients with chronic hepatitis B virus (HBV) infection but not in treatment-experienced patients. Owing to the wide availability of antiviral agents that effectively suppress HBV replication, we investigated HCC risk factors in treatment-experienced patients. METHODS: In a cohort of 330 patients who underwent pretherapeutic liver biopsy, we analyzed the HCC incidence in relationship to clinical parameters. Ultra-deep sequencing of the viral genome was performed on 11 entecavir-treated and pegylated interferon (peginterferon)-treated patients. RESULTS: Initial univariate/multivariate explorations indicated that cirrhosis and antiviral treatment were independently associated with HCC occurrence. The peginterferon-experienced patients had a lower HCC incidence than the nucleos(t)ide analogue-treated patients (P = .011). The peginterferon and entecavir monotherapy groups also differed in HCC incidence (P = .018). Results of analysis of baseline-matched subgroups concurred with cohort analysis (P = .009 for comparison of peginterferon-experienced vs nucleotide analogue-treated patients; P = .022 for comparison of peginterferon- vs entecavir-treated patients). Viral loads of entecavir-treated patients were constantly suppressed to levels lower than those of peginterferon-treated patients (P < .001). Oncogenic surface antigen truncation mutations were detected in entecavir-treated patients with HCC but not in peginterferon-treated patients (P = .015). CONCLUSIONS: Treatment by peginterferon was associated with a lower HCC incidence than nucleos(t)ide-analogue treatment in chronic HBV infection.

Clinical Predictors for Neutrophil-to-Lymphocyte Ratio Changes in Patients with Chronic Hepatitis B Receiving Peginterferon Treatment.

BACKGROUND: A lower neutrophil-to-lymphocyte ratio (NLR) was found to be associated with better clinical outcomes in hepatitis B-related liver cirrhosis and hepatocellular carcinoma. We aimed to identify pre-therapeutic variables capable of predicting NLR changes in patients with hepatitis B receiving peginterferon therapy. PATIENTS AND METHODS: The baseline clinicopathological data were analyzed to correlate with NLR changes before and 1 year after peginterferon treatment in 71 patients with hepatitis B. RESULTS: Univariate analysis revealed that pre-treatment NLR itself negatively predicted NLR changes following peginterferon treatment (odds ratio(OR)=0.320, p=0.013). Further analysis identified pre-treatment NLR, hemoglobin and hepatitis B surface antigen level as independent predictors for NLR changes (adjusted p=0.028, 0.005, and 0.028, respectively). A predictive score composed of these three factors had an area under the curve of 76.5% (p<0.001). CONCLUSION: Pretreatment NLR, hemoglobin and hepatitis B surface antigen level in combination, effectively predicted NLR changes following peginterferon treatment.