title: Bystander effect contributes to the antitumor efficacy of CaSm antisense gene therapy in a preclinical model of advanced pancreatic cancer.
abstract: Pancreatic adenocarcinoma (PC) is an aggressive malignancy resistant to standard treatment modalities. Previously, we have reported that cancer-associated Sm-like protein (CaSm) contributes to the neoplastic transformation of PC. In this study, we utilized a recently established preclinical model of PC to determine if molecular targeting of CaSm can serve as the basis for a novel PC therapy. In a subcutaneous tumor model, intratumoral administration of an adenoviral vector encoding CaSm antisense RNA (Ad-alphaCaSm) significantly inhibited Panc02 tumor growth. Furthermore, in a metastatic tumor model, systemic administration of Ad-alphaCaSm resulted in a significant decrease in the number of hepatic metastases and increased survival time. We assessed the efficiency of in vivo delivery and observed significant levels of vector transduction in tissues containing PC, as well as a bystander effect that was amplifying the efficacy of CaSm gene therapy. This bystander effect was also active in vitro and was shown to be at least partially independent of host-related mechanisms. We conclude that CaSm antisense gene therapy is an effective novel therapy for PC and that the antitumor efficacy is dependent on both direct and bystander mechanisms.
authors.affiliation: Department of Surgery, Hollings Cancer Center, Medical University of South Carolina, Charleston, 29425, USA.
authors.forename: Yan
authors.initials: Y
authors.lastname: Yan
authors.forename: Semyon
authors.initials: S
authors.lastname: Rubinchik
authors.forename: April L
authors.initials: AL
authors.lastname: Wood
authors.forename: William E
authors.initials: WE
authors.lastname: Gillanders
authors.forename: Jian-Yun
authors.initials: JY
authors.lastname: Dong
authors.forename: Dennis K
authors.initials: DK
authors.lastname: Watson
authors.forename: David J
authors.initials: DJ
authors.lastname: Cole
mesh_terms: D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D024201:Bystander Effect / Q000235:genetics*; D002460:Cell Line; D045744:Cell Line, Tumor; D004353:Drug Evaluation, Preclinical; D005260:Female; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors / Q000008:administration & dosage / Q000627:therapeutic use; D008114:Liver Neoplasms, Experimental / Q000556:secondary / Q000628:therapy / Q000821:virology; D051379:Mice; D008810:Mice, Inbred C57BL; D010190:Pancreatic Neoplasms / Q000628:therapy* / Q000821:virology; D011518:Proto-Oncogene Proteins / Q000008:administration & dosage* / Q000235:genetics* / Q000378:metabolism; D016372:RNA, Antisense / Q000627:therapeutic use*; D016601:RNA-Binding Proteins; D014161:Transduction, Genetic
chemical_list: C502231:Lsm1 protein, mouse; D011518:Proto-Oncogene Proteins; D016372:RNA, Antisense; D016601:RNA-Binding Proteins