Newcastle Disease Virus Exerts Oncolysis by both Intrinsic and Extrinsic Caspase-Dependent Pathways of Cell Death

Abstract

Newcastle disease virus (NDV), an avian paramyxovirus, is tumor selective and intrinsically oncolytic. Here, we present evidence that genetically modified, recombinant NDV strains are cytotoxic to human tumor cell lines of ecto-, endo-, and mesodermal origin. We show that cytotoxicity against tumor cells is due to multiple caspase-dependent pathways of apoptosis independent of interferon signaling competence. The signaling pathways of NDV-induced, cancer cell-selective apoptosis are not well understood. We demonstrate that NDV triggers apoptosis by activating the mitochondrial/intrinsic pathway and that it acts independently of the death receptor/extrinsic pathway. Caspase-8-methylated SH-SY5Y neuroblastoma cells are as sensitive to NDV as other caspase-8-competent cells. This demonstrates that NDV is likely to act primarily through the mitochondrial death pathway. NDV infection results in the loss of mitochondrial membrane potential and the subsequent release of the mitochondrial protein cytochrome c, but the second mitochondrion-derived activator of caspase (Smac/DIABLO) is not released. In addition, we describe early activation of caspase-9 and caspase-3. In contrast, cleavage of caspase-8, which is predominantly activated by the death receptor pathway, is a TNF-related, apoptosis-inducing ligand (TRAIL)-induced late event in NDV-mediated apoptosis of tumor cells. Our data, therefore, indicate that the death signal(s) generated by NDV in tumor cells ultimately converges at the mitochondria and that it acts independently of the death receptor pathway. Our cytotoxicity studies demonstrate that recombinant NDV could be developed as a cancer virotherapy agent, either alone or in combination with therapeutic transgenes. We have also shown that trackable oncolytic NDV could be developed without any reduction in oncolytic efficacy.

Mitochondrion-mediated apoptosis induced by Rana grylio virus infection in fish cells

“…Virus infection has been observed to be associated with apoptosis [8][9][10][11], and the molecular mechanisms and signal pathways have been disclosed in virus infection of mammal cells [12,13]. Apoptosis of fish cells can be also triggered by virus infection [14][15][16], but systematic studies on mitochondrial dynamics and the molecular mechanisms are very limited.…”

Selective oncolytic effect of an attenuated Newcastle disease virus (NDV-HUJ) in lung tumors

“…Apoptotic activity of another NDV lentogenic strain (rLaSota) in a variety of tumor cells was demonstrated previously but no comparison to nontumorigenic cells was shown. 3 Interestingly, when the apoptotic activities of NDV and ETO, a standard anti cancer drug, were compared, the two agents appear to function in a different mode. Although proliferating nontumorigenic cells were highly sensitive to ETO, as compared to tumor cells, they were less sensitive to NDV.…”

“…Newcastle disease virus (NDV), an avian paramyxovirus, has been evaluated in experimental models and in some clinical studies as an anti cancer agent and some therapeutic benefits have been reported. [3][4][5] Two major approaches were undertaken in these studies: first, the virus was applied to directly infect and kill the tumor cells. 4,[6][7][8] Second, the virus was used as an immunomodulatory agent by infecting autologous cells ex vivo, followed by injection of the 'xenogenized' cells to induce immune surveillance against the tumor.…”

Cross-infection of tumor cells by contact with T lymphocytes loaded with Newcastle disease virus

“…Single cell suspensions were obtained from spleens and lymph nodes of Balb/c mice. Lysis of erythrocytes was performed with 155 mM NH 4 Cl, 10 mM KHCO 3 and 0.1 mM EDTA. Mouse T cells were purified using the Dynal mouse T cell Negative Isolation Kit from Invitrogen (Karlsruhe, Germany).…”