Mechanisms of cell death induced by suicide genes encoding purine nucleoside phosphorylase and thymidine kinase in human hepatocellular carcinoma cells in vitro

Krohne, Tim U.; Shankara, Srinivas; Geißler, Michael; Roberts, Bruce; Wands, Jack R.; Blum, Hubert E.; Mohr, Leonhard

doi:10.1053/jhep.2001.26749

Cited by 54 publications

(34 citation statements)

References 44 publications

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“…31,32 An in vitro study of the GSVtk and PNP-GDEPT systems showed that the latter produced more tumor cell apoptosis than the former, and that the induction of apoptosis by PNP/fludarabine-GDEPT was independent of p53 status and the Fas/FasL pathway. 33 LNCaP tumors express phenotypically wild-type p53 34 and this is likely to be the case for LN3 cells. PC3 cells are p53 null.…”

Section: Discussionmentioning

confidence: 98%

Preclinical evaluation of a prostate-targeted gene-directed enzyme prodrug therapy delivered by ovine atadenovirus

et al. 2004

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Gene-directed enzyme prodrug therapy (GDEPT) based on the Escherichia coli enzyme, purine nucleoside phosphorylase (PNP), provides a novel strategy for treating slowly growing tumors like prostate cancer (CaP). PNP converts systemically administered prodrug, fludarabine phosphate, to a toxic metabolite, 2-fluoroadenine, that kills PNP-expressing and nearby cells by inhibiting DNA, RNA and protein synthesis. Reporter gene expression directed by a hybrid prostatedirected promoter and enhancer, PSMEPb, was assayed after plasmid transfection or viral transduction of prostate and nonCaP cell lines. Androgen-sensitive (AS) LNCaP-LN3 and androgen-independent (AI) PC3 human CaP xenografts in nude mice were injected intratumorally with an ovine atadenovirus vector, OAdV623, that carries the PNP gene under PSMEPb, formulated with cationic lipid for enhanced infectivity. Fludarabine phosphate was then given intraperitoneally for 5 days at 75 mg/m 2 /day. PNP expression was evaluated by enzymic conversion of its substrate using reverse phase HPLC. OAdV623 showed excellent in vitro transcriptional specificity for CaP cells. In vivo, expression of PNP persisted for 46 days after OAdV623 injection and a single treatment provided 100% increase in tumor doubling time and 450% inhibition of tumor growth for both LNCaP-LN3 and PC3 lines, with increased tumor necrosis and apoptosis and decreased tumor cell proliferation. OAdV623 significantly suppressed the growth of AS and AI human CaP xenografts in mice.

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Section: Discussionmentioning

confidence: 98%

Preclinical evaluation of a prostate-targeted gene-directed enzyme prodrug therapy delivered by ovine atadenovirus

et al. 2004

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“…In addition, PI staining results showed that the ePNP/MePdR system increased the spontaneous apoptosis of tumor cells (Figure 3), consistent with those results reported previously. 18 We also observed a high bystander killing effect induced by the ePNP/MePdR system, with a very low proportion (1%) of SC/ePNP-infected cells (Figure 4). The data presented here indicated that the ePNP/MePdR system could increase the spontaneous apoptosis of the tumor cells, and that its killing effect to the bystander cells was caused by a high bystander effect.…”

Section: Discussionmentioning

confidence: 65%

“…[9][10][11][12][13] Therefore, expression of ePNP is able to kill a number of cancer cells in vitro when a small fraction of cells (for example, 0.1-3%) express this suicide gene, in combination with MePdR administration. 8,[14][15][16][17][18] As expression of suicide genes will not be achieved in all the tumor cells, a bystander effect is necessary to produce toxic metabolites to kill not only the positive cells but also the bystander cells. [19][20][21] The ePNP/ MePdR system differs from other GDEPT systems, because the toxic metabolites of this system will readily cross the cell membrane and not require direct cell-to-cell contact or the presence of a gap junction.…”

Section: Introductionmentioning

confidence: 99%

Synergistic antitumor efficacy of suicide/ePNP gene and 6-methylpurine 2′-deoxyriboside via Salmonella against murine tumors

Lan

et al. 2008

Cancer Gene Ther

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Some anaerobes and facultative anaerobes have been used in tumor-specific gene therapy by reason of their selective growth in tumors. In this work, we aimed to evaluate the anticancer efficacy of attenuated Salmonella typhimurium as a carrier to deliver the Escherichia coli purine nucleoside phosphorylase (ePNP) gene for GDEPT (gene-directed enzyme-prodrug therapy). A live attenuated purine-auxotrophic strain of S. typhimurium (SC36) was used to carry the pEGFP-C1-ePNP vector that contains a green fluorescent protein (GFP) and an ePNP gene under the control of the human cytomegalovirus (CMV) promoter. The function of the ePNP expression vector was confirmed in vitro using the enzymic conversion of 6-methylpurine 2 0 -deoxyriboside (MePdR) into 6-methylpurine. We also observed a high bystander effect induced by the ePNP/MePdR system with a very low proportion (1%) of ePNP-positive cells. The killing effect and increased apoptosis induced by SC/ePNP (SC36 carrying the ePNP expression vector) infection were detected by cytotoxicity assay and PI staining flow cytometry analysis, in combination with MePdR administration. Furthermore, SC/ePNP was administered orally into mice bearing melanomas or pulmonary tumors, and its anti-tumor effect was evaluated. When the tumor was huge (500 mm 3 ) at the beginning of MePdR administration, SC/ePNP plus MepdR significantly inhibited tumor growth by about 59-80% and prolonged survival of mice. Complete tumor regression and long-term cure were achieved by MePdR administration, even when the tumor was large (100 mm 3 ) at the beginning of MePdR treatment. Our data support a hopeful view that tumor-targeting SC36 could improve antitumor efficacy of the ePNP/MePdR system due to its preferential accumulation and anticancer activity in tumors.

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“…48 Both prodrug-activating systems induce apoptosis in Transduction of PNP gene followed by treatment with nucleoside analogues has been studied in vivo on bladder tumors, pancreatic adenocarcinomas, gliomas, ovarian or prostate tumors and showed different levels of growth inhibition. 40,44,[49][50][51][52][53][54][55][56] To increase the effect obtained with this gene-therapy approach by using new genes and new drugs, a study based on crystallographic and computer modeling of E. coli PNP, was performed.…”

Section: Gene Therapy and Nucleoside Analogues C Hébrard Et Almentioning

confidence: 99%

Development of gene therapy in association with clinically used cytotoxic deoxynucleoside analogues

2009

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The clinical use of cytotoxic deoxynucleoside analogues is often limited by resistance mechanisms due to enzymatic deficiency, or high toxicity in nontumor tissues. To improve the use of these drugs, gene therapy approaches have been proposed and studied, associating clinically used deoxynucleoside analogues such as araC and gemcitabine and suicide genes or myeloprotective genes. In this review, we provide an update of recent results in this area, with particular emphasis on human deoxycytidine kinase, the deoxyribonucleoside kinase from Drosophila melanogaster, purine nucleoside phosphorylase from Escherichia coli, and human cytidine deaminase. Data from literature clearly show the feasibility of these systems, and clinical trials are warranted to conclude on their use in the treatment of cancer patients.

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Mechanisms of cell death induced by suicide genes encoding purine nucleoside phosphorylase and thymidine kinase in human hepatocellular carcinoma cells in vitro

Cited by 54 publications

References 44 publications

Preclinical evaluation of a prostate-targeted gene-directed enzyme prodrug therapy delivered by ovine atadenovirus

Preclinical evaluation of a prostate-targeted gene-directed enzyme prodrug therapy delivered by ovine atadenovirus

Synergistic antitumor efficacy of suicide/ePNP gene and 6-methylpurine 2′-deoxyriboside via Salmonella against murine tumors

Development of gene therapy in association with clinically used cytotoxic deoxynucleoside analogues

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