Abstract
PurposeOncolytic viral therapy for neuroblastoma (NB) cells with Sindbis virus (SINV) is a promising strategy for treating high-risk NB. Here, we evaluated the possibility of using SINV structural proteins as therapeutic agents for NB since UV-inactivated SINV could induce cytopathogenic effects.MethodsThe cytotoxicity of UV-inactivated SINV toward human NB cell lines NB69, NGP, GOTO, NLF, SK-N-SH, SH-SY5Y, CHP134, NB-1, IMR32, and RT-BM-1 were analyzed. Apoptosis was confirmed by TUNEL assays. To determine the components of SINV responsible for the cytotoxicity of UV-inactivated SINV, expression vectors encoding the structural proteins, namely capsid, E2, and E1, were transfected in NB cells. Cytotoxicity was evaluated by MTT assays.ResultsUV-inactivated SINV elicited more significant cytotoxicity in NB69, NGP, and RT-BM-1 than in normal human fibroblasts. Results of the transfection experiments showed that all NB cell lines susceptible to UV-inactivated SINV were highly susceptible to the E1 protein, whereas fibroblasts transfected with vectors harboring capsid, E1, or E2 were not.ConclusionsWe demonstrated that the cytotoxicity of the UV-inactivated SINV is due to apoptosis induced by the E1 structural protein of SINV, which can be used selectively as a therapeutic agent for NB.
Highlights
Neuroblastoma (NB) is the most common solid extracranial tumor of early childhood [1, 2]
Human NB cell lines were grown in Roswell Park Memorial Institute (RPMI) 1640 medium supplemented with 10% heat-inactivated fetal bovine serum (FBS) and 100 μg/mL kanamycin
Cell viability assays showed that UV-inactivated Sindbis virus (SINV) was cytotoxic for NB cells after 48 h, and elicited evident effects on NB69 and NGP cells in a dose-dependent manner; the levels of cytotoxicity induced by UV-inactivated SINV was lower than that induced by replication-competent SINV (Fig. 1a)
Summary
Neuroblastoma (NB) is the most common solid extracranial tumor of early childhood [1, 2]. The resistance of NBs to conventional therapies has prompted the search for a novel therapeutic approach based on the naturally occurring oncolytic virus, Sindbis virus (SINV). We have reported that the SINV AR339 strain may be used as a novel therapeutic agent for human cervical, ovarian, and oral cancer [6,7,8]. SINV, a mosquito-borne alphavirus, is an enveloped, plus-strand RNA virus that causes infection of neurons and age-dependent encephalomyelitis in mice, and mild mosquito-borne viral arthritis in humans [10]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
