A Comparative Safety Profile Assessment of Oncolytic Virus Therapy Based on Clinical Trials.

Oncolytic virus therapy (OVT) represents a new class of therapeutic agents in cancer treatment. The molecular and cellular mechanisms of action of OVTs have been evaluated in nonclinical/clinical phase trials. Various genetically modified viruses have been developed as oncolytic agents, and the first approval of an OVT for clinical use was issued by the US Food and Drug Administration in 2015. In this context, more and more clinical development of OVTs is anticipated in the future. This article provides a risk assessment of OVT based on the safety data obtained from all clinical trials to date using a publicly available database. The most common adverse events (AEs) observed in clinical trials have been infection-related symptoms such as fatigue, chills, fever, and nausea; few serious AEs have been observed, regardless of the kind of virus or transfected genes. In vivo systemic infusion of OVTs demonstrated a high percentage of AEs, but most AEs were manageable using common drugs. This paper describes OVTs' specific safety/toxicity profiles and encourages the performance of further clinical trials of OVTs to address the most serious challenges anticipated in the development of OVTs as a new class of drugs for the treatment of cancer.

Zinc chloride exposure increases heme oxygenase-1 expression in MDPC-23 odontoblast-like cells.

OBJECTIVE: The aim of this study is to clarify the effects of zinc chloride (ZnCl2) exposure on the induction of heme oxygenase-1 (HO-1) expression and its regulatory mechanisms in MDPC-23 mouse odontoblast-like cells. METHODS: MDPC-23 cells were incubated with ZnCl2, and the levels of HO-1 protein, phosphorylated forms of mitogen-activated protein kinases (MAPKs), including extracellular signal-regulated protein kinase (ERK), c-Jun NH2-terminal kinase (JNK), and p38, and phosphorylated forms of amino kinase terminal (Akt) and nuclear factor-κB (NF-κB) p65 were determined with western immunoblotting. The level of HO-1 mRNA was determined with RT-PCR analysis. After pretreatment with inhibitors of ERK, JNK, p38, phosphoinositide-3 kinase (PI3K), and NF-κB, HO-1 protein level was determined in MDPC-23 cells exposed to ZnCl2. RESULTS: Following exposure to 500µM ZnCl2, the levels of both HO-1 mRNA and protein were markedly increased. The phosphorylated forms of ERK, JNK, and p38 increased after ZnCl2 exposure. Furthermore, the expression of HO-1 was markedly suppressed by treatment with the p38 inhibitor, SB203580, and mildly suppressed by the MAPK/ERK kinase inhibitor, U0126. However, treatment with the JNK inhibitor, SP600125, did not suppress ZnCl2-induced HO-1 expression. In addition, the phosphorylated forms of Akt, a downstream kinase of PI3K, and NF-κB p65 increased after ZnCl2 exposure. Treatment with the PI3K inhibitor, LY294002, and the NF-κB inhibitor, Bay11-7082, suppressed ZnCl2-induced HO-1 expression. CONCLUSION: These results suggest that ZnCl2 exposure induces HO-1 expression via multiple intracellular signalling pathways, including p38, ERK, PI3K/Akt, and NF-κB, in this odontoblast-like cell line.