Effective infection, apoptotic cell killing and gene transfer of human hepatoma cells but not primary hepatocytes by parvovirus H1 and derived vectors

Abstract

Autonomous parvoviruses preferentially replicate in and kill in vitro ± transformed cells and reduce the incidence of spontaneous and implanted tumors in animals. Because of these natural oncotropic and oncolytic properties, parvoviruses deserve to be considered as potential antitumor vectors. Here, we assessed whether parvovirus H1 is able to kill human hepatoma cells by induction of apoptosis but spares primary human liver cells, and whether the former cells can efficiently be transduced by H1 virus ± based vectors. Cell death, infectivity, and transgene transduction were investigated in Hep3B, HepG2, and Huh7 cells and in primary human hepatocytes with natural and recombinant H1 virus. All hepatoma cells were susceptible to H1 virus ± induced cytolyis. Cell death correlated with H1 virus DNA replication, nonstructural protein expression, and with morphological features of apoptosis. H1 virus ± induced apoptosis was more pronounced in p53 -deleted Hep3B and p53 -mutated Huh7 cells than in HepG2 cells which express wild -type p53. In Hep3B cells, apoptosis was partially inhibited by DEVD -CHO, a caspase -3 inhibitor. In contrast, H1 virus ± infected primary hepatocytes were neither positive for nonstructural protein expression nor susceptible to H1 virus ± induced killing. Infection with a recombinant parvovirus vector carrying the luciferase gene under control of parvovirus promoter P38 led to higher transgene activities in hepatoma cells than in the hepatocytes. Taken together, H1 virus kills human hepatoma cells at low virus multiplicity but not primary hepatocytes. Thus, recombinant H1 viruses carrying antitumor transgenes may be considered as potential therapeutic options for the treatment of hepatocellular carcinomas. Cancer Gene Therapy ( 2001 ) 8, 158 ± 167

Single-stranded RNA viruses inactivate the transcriptional activity of p53 but induce NOXA-dependent apoptosis via post-translational modifications of IRF-1, IRF-3 and CREB

“…These results were confirmed by Northern blot analysis (Figure 1a). To determine whether Noxa mRNA induction was restricted to SV infection and/or dependent on p53 activation, experiments were carried out using HSV-1, a DNA virus and HuH7 cells, which contain a functionally inactive p53 gene (Moehler et al, 2001). As shown in Figure 1a, both SV and HSV-1 infection markedly induced expression of NOXA transcripts in both p53 positive and negative cell lines.…”

Activation of the human immune system via toll‐like receptors by the oncolytic parvovirus H‐1

“…35 Previous analyses have demonstrated that H-1PV was able to induce specific immune responses against the tumor and TCLs. 4 Therefore, autonomous parvoviruses offer a new approach in the treatment of cancer, although the susceptibility of the tumor cells to H-1PV infection is dependent on the origin of the tumor and the proliferation capacity of the cells. 36 Based on previous studies which analyzed TLR-2, -3, -4, -6 and -9 -transfected HEK293 cells (data not shown), only a TLR3-and TLR9-mediated activation of NFkB could be detected after H-1PV infection.…”

“…1,2 One special characteristic of these rodent viruses is their absence of pathogenicity in adult animals and if any, is restricted to proliferating tissues and to fetuses or neonates. 3 H-1PV is considered oncotropic, efficiently infecting transformed human cell lines and human tumor cells, including melanoma, hepatoma, colon and gastric cancer cells [4][5][6] ; however, in contrast to these fast replicating cells, human immune cells and primary hepatocytes are not infected or lysed. 4,5,7 It was reported that H-1PV can also replicate in humans after injection without causing severe adverse reactions.…”

“…3 H-1PV is considered oncotropic, efficiently infecting transformed human cell lines and human tumor cells, including melanoma, hepatoma, colon and gastric cancer cells [4][5][6] ; however, in contrast to these fast replicating cells, human immune cells and primary hepatocytes are not infected or lysed. 4,5,7 It was reported that H-1PV can also replicate in humans after injection without causing severe adverse reactions. 8,9 H-1PV has oncotropic and oncolytic properties and was shown to trigger oncosuppressive effects against different malignancies.…”

Adaptive T cell responses induced by oncolytic Herpes Simplex Virus-granulocyte macrophage-colony-stimulating factor therapy expanded by dendritic cell and cytokine-induced killer cell adoptive therapy

“…1,2 Oncolytic viral therapy (OVT) utilizes the selective replication of viruses in cancer cells to lyse tumor cells and release tumor antigens, while leaving normal tissue unaffected. 3,4 OVT represents an emerging therapeutic modality that has achieved tumor regression in clinical trials.…”