OBJECTIVESome research has shown that Newcastle disease virus (NDV) is effective in the treatment of various tumors, including transferred melanoma and well differentiated renal cell carcinoma. This study aimed to evaluate the effect of NDV against human acute monocytic leukemia SHI-1 cells in vitro and in vivo.

METHODSIn vitro, the density and morphologic changes between wild SHI-1 cells (control) and NDV-infected SHI-1 cells were observed. MTT assay was utilized to observe the effect of NDV on the proliferation of SHI-1 cells. In vivo, the effect of NDV on the tumor inhibition was assessed using SHI-1 xenografts subcutaneously established in CD-1 nude mice. NDV was given by intra-tumor injections, and the tumor inhibition rate and toxic effects were evaluated.

RESULTSIn the control group, the SHI-1 cells were observed using an inverted microscope to be regular in morphology and intensive in distribution. In the NDV-infected group, the SHI-1 cells were irregular and sparsate, and the aggregate and fused cells were common. MTT assay showed that the proliferation of SHI-1 cells were significantly inhibited by NDV at different concentrations (P<0.01) and in a time- and concentration-dependent manner. The tumor inhibition rate in the NDV group was 84.7%, which was significantly higher than that in the control group (P<0.01). No toxic effects were observed in the nude mice.

CONCLUSIONSNDV can suppress the proliferation of human acute monocytic leukemic cells both in vitro and in vivo. The safety of NDV is reliable.