title: In vitro and in vivo characterisation of a novel c-FLIP-targeted antisense phosphorothioate oligonucleotide.
abstract: Previous studies have suggested that the caspase 8 inhibitor FLIP is a promising anti-cancer therapeutic target. In this study, we characterised a novel FLIP-targeted antisense phosphorothioate oligonucleotide (AS PTO). FLIP AS and control PTOs were assessed in vitro in transient transfection experiments and in vivo using xenograft models in Balb/c nude mice. FLIP expression was assessed by QPCR and Western. Apoptosis induction was determined by flow cytometry and Western. Of 5 sequences generated, one potently down-regulated FLIP. AS PTO-mediated down-regulation of FLIP resulted in caspase 8 activation and apoptosis induction in non-small cell lung (NSCLC) cells but not in normal lung cells. Similar results were observed in colorectal and prostate cancer cells. Furthermore, the FLIP AS PTO sensitized cancer cells but not normal lung cells to apoptosis induced by rTRAIL. Moreover, the FLIP AS PTO enhanced chemotherapy-induced apoptosis in NSCLC cells. Importantly, compared to a control non-targeted PTO, intra-peritoneal delivery of FLIP AS PTO inhibited the growth of NSCLC xenografts and enhanced the in vivo antitumour effects of cisplatin. We have identified a novel FLIP-targeted AS PTO that has in vitro and in vivo activity and which therefore has potential for further pre-clinical development.
authors.affiliation: Drug Resistance Laboratory, Centre for Cancer Research and Cell Biology, Queen's University Belfast, 97 Lisburn Road, Belfast BT97BL, Northern Ireland, UK.
authors.forename: Andrew E
authors.initials: AE
authors.lastname: Logan
authors.forename: Timothy R
authors.initials: TR
authors.lastname: Wilson
authors.forename: Catherine
authors.initials: C
authors.lastname: Fenning
authors.forename: Rob
authors.initials: R
authors.lastname: Cummins
authors.forename: Elaine
authors.initials: E
authors.lastname: Kay
authors.forename: Patrick G
authors.initials: PG
authors.lastname: Johnston
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Longley
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics; D053446:CASP8 and FADD-Like Apoptosis Regulating Protein / Q000235:genetics / Q000378:metabolism*; D002289:Carcinoma, Non-Small-Cell Lung / Q000235:genetics / Q000378:metabolism* / Q000628:therapy; D053181:Caspase 8 / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D002945:Cisplatin / Q000494:pharmacology; D015179:Colorectal Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000628:therapy; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000628:therapy; D008297:Male; D051379:Mice; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D016376:Oligonucleotides, Antisense / Q000235:genetics / Q000494:pharmacology / Q000627:therapeutic use; D054735:Phosphorothioate Oligonucleotides / Q000235:genetics / Q000494:pharmacology / Q000627:therapeutic use; D011471:Prostatic Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000628:therapy; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism*; D053221:TNF-Related Apoptosis-Inducing Ligand / Q000378:metabolism
chemical_list: D000970:Antineoplastic Agents; D053446:CASP8 and FADD-Like Apoptosis Regulating Protein; D016376:Oligonucleotides, Antisense; D054735:Phosphorothioate Oligonucleotides; D034741:RNA, Small Interfering; D053221:TNF-Related Apoptosis-Inducing Ligand; D053181:Caspase 8; D002945:Cisplatin