title: Bcl-xL antisense oligonucleotide and cisplatin combination therapy extends survival in SCID mice with established mesothelioma xenografts.
abstract: Bcl-xL functions as a dominant regulator of apoptotic cell death and is implicated in chemotherapeutic resistance of malignant pleural mesothelioma (MPM). Mesothelioma cell lines demonstrate increasing levels of Bcl-xL as resistant clones are selected in vitro. Moreover, upon introduction of antisense oligonucleotides specific to Bcl-xL mRNA, MPM cells are sensitized to chemotherapeutic agents. Here we describe the therapeutic effects of a novel combination therapy, Bcl-xL antisense oligonucleotide (ASO 15999) and cisplatin, on mesothelioma cell lines in vitro and in vivo; in addition, efficacy of ASO 15999 in decreasing tumor load as well as its effect on survival in an animal model. Finally, we initiated preliminary toxicity studies involved with intraperitoneal (IP) injections of ASO 15999 into mice. This novel combination, with doses of cisplatin four times below established IC(50) levels, significantly decreased viability of MPM cell lines after 48 hr. The growth of established mouse flank human tumor xenografts was reduced with intra-tumor administration of ASO 15999. Local spread and development of IP xenografts was reduced with treatments of ASO alone, and survival of mice afflicted with these xenografts was prolonged after administration of ASO alone and ASO 15999 + cisplatin combination therapy. These findings suggest that ASO 15999 sensitizes MPM cell lines to the toxic effects of cisplatin. ASO 15999 induced reduction of Bcl-xL is effective in slowing the progression of human mesothelioma cell lines both in vitro and in vivo. More notably, the combination of Bcl-xL ASO and cisplatin extends survival in an orthotopic tumor xenograft model.
authors: Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College of Medicine, College Station, TX, USA. jelittlejohn@medicine.tamhsc.edu
authors: James E
authors: JE
authors: Littlejohn
authors: Xiaobo
authors: X
authors: Cao
authors: Steven D
authors: SD
authors: Miller
authors: Mustafa K
authors: MK
authors: Ozvaran
authors: Daniel
authors: D
authors: Jupiter
authors: Lidong
authors: L
authors: Zhang
authors: Charles
authors: C
authors: Rodarte
authors: W Roy
authors: WR
authors: Smythe
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology* / Q000627:therapeutic use; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology; D045744:Cell Line, Tumor; D002945:Cisplatin / Q000008:administration & dosage; D006801:Humans; D020128:Inhibitory Concentration 50; D007274:Injections, Intraperitoneal; D053208:Kaplan-Meier Estimate; D008654:Mesothelioma / Q000188:drug therapy*; D051379:Mice; D016513:Mice, SCID; D016376:Oligonucleotides, Antisense / Q000008:administration & dosage / Q000378:metabolism / Q000494:pharmacology* / Q000633:toxicity; D010997:Pleural Neoplasms / Q000188:drug therapy*; D013997:Time Factors; D023041:Xenograft Model Antitumor Assays; D051020:bcl-X Protein / Q000008:administration & dosage / Q000378:metabolism / Q000494:pharmacology*
chemical_list: D000970:Antineoplastic Agents; C494811:BCL2L1 protein, human; D016376:Oligonucleotides, Antisense; D051020:bcl-X Protein; D002945:Cisplatin