title: Modulation of tumor radiation response with G3139, a bcl-2 antisense oligonucleotide.
abstract: Overexpression of anti-apoptotic bcl-2 protein has been found in hematological and solid tumors and has been associated with increased resistance against cytotoxic therapy. While bcl-2 antisense (AS) treatment combined with chemotherapy has been successfully tested in clinical trials, trials evaluating the combination of bcl-2 AS with radiotherapy have not yet been performed. The aim of this study was to investigate in vivo anti-tumor effects of a combined modality treatment scheme consisting of radiation and the bcl-2 targeted AS oligonucleotide (ODN) G3139 (Oblimersen Sodium). Two human colon carcinoma cell lines, SW620, bcl-2 positive and HT-29, bcl-2 negative, were grown as xenografts and compared in their response to combined bcl-2 AS/radiation treatment. G3139 potentiated the radiation response of bcl-2 positive SW620 tumors, but had no significant effect on bcl-2 negative HT-29 tumors assayed by tumor growth delay. The profound enhancement of SW620 tumor growth delay by G3139 did not translate into effects on tumor cure, as no significant effect of G3139 was found on SW620 radiocurability (TCD50 assay). The control ODN G3622 had no effect on SW620 radiation response, indicating an ODN sequence specific effect.
authors.affiliation: Department of Experimental Radiation Oncology, The University of Texas M. D. Anderson Cancer Center, Unit 066, Houston, TX 77030-4009, USA.
authors.forename: Nicole
authors.initials: N
authors.lastname: Wiedenmann
authors.forename: Masashi
authors.initials: M
authors.lastname: Koto
authors.forename: Uma
authors.initials: U
authors.lastname: Raju
authors.forename: Luka
authors.initials: L
authors.lastname: Milas
authors.forename: Kathryn A
authors.initials: KA
authors.lastname: Mason
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000627:therapeutic use; D002277:Carcinoma / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology / Q000532:radiotherapy*; D045744:Cell Line, Tumor; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology / Q000532:radiotherapy*; D003131:Combined Modality Therapy; D019938:Cyclin D1 / Q000378:metabolism; D005720:Gamma Rays; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D016376:Oligonucleotides, Antisense / Q000627:therapeutic use*; D013873:Thionucleotides / Q000627:therapeutic use*; D047368:Tumor Burden / Q000187:drug effects / Q000528:radiation effects
chemical_list: D000970:Antineoplastic Agents; D016376:Oligonucleotides, Antisense; D013873:Thionucleotides; D019938:Cyclin D1; C408162:oblimersen