Induction of apoptosis in BCL-2-expressing rat prostate cancer cells using the Semliki Forest virus vector.
The Semliki Forest virus (SFV) vector is a transient RNA expression vector that has an inherent p53-independent apoptosis-inducing property. It is administered as recombinant SFV particles (rSFV) that undergo 1 round of replication only and express a gene cloned into the multicloning site. In our study we have investigated the ability of the SFV vector to induce apoptosis and inhibit tumour growth in rat prostate cancer (AT3-Neo) cells expressing the Bcl-2 oncogene (AT3-Bcl-2 cells), which normally inhibits apoptosis. rSFV expressing the enhanced green fluorescent protein (EGFP) gene (rSFV-EGFP), or recombinant RNA transfected into cells by electroporation, induced delayed apoptosis in AT3-Bcl-2 cells. SFV-mediated expression of a cloned pro-apoptotic Bax gene by the vector, however, enhanced apoptosis induction both in AT3-Bcl-2 cells and standard BHK-21 cells. Such Bax-expressing particles could be produced only at low titers compared to EGFP-expressing particles under standard conditions for particle production, but lowering the incubation temperature for particle production to 33 degrees C partially alleviated this effect. Bax-expressing particles were shown to inhibit the growth of AT3-Neo and AT3-Bcl-2 tumours in nude mice, as did high titre EGFP-expressing particles. It is concluded that SFV recombinant particles have potential as anti-tumour agents to treat apoptosis-resistant tumours.
Murphy
A M
AM
Department of Microbiology, Moyne Institute of Preventive Medicine, Trinity College, Dublin, Ireland.
Sheahan
B J
BJ
Atkins
G J
GJ
D000818:Animals; D017209:Apoptosis; D002470:Cell Survival; D003001:Cloning, Molecular; D006224:Cricetinae; D005822:Genetic Vectors; D049452:Green Fluorescent Proteins; D006801:Humans; D008164:Luminescent Proteins / Q000378:metabolism; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D011471:Prostatic Neoplasms / Q000378:metabolism* / Q000473:pathology*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D012672:Semliki forest virus / Q000235:genetics*; D013997:Time Factors; D014161:Transduction, Genetic; D014162:Transfection; D014407:Tumor Cells, Cultured
D008164:Luminescent Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; D049452:Green Fluorescent Proteins