title: Combined suicide gene therapy for pancreatic peritoneal carcinomatosis using BGTC liposomes.
abstract: Peritoneal dissemination is a common end-stage complication of pancreatic cancer for which novel therapeutic modalities are actively investigated, as there is no current effective therapy. Thus, we evaluated, in a mouse model of pancreatic peritoneal carcinomatosis, the therapeutic potential of a novel nonviral gene therapy approach consisting of bis-guanidinium-tren-cholesterol (BGTC)-mediated lipofection of a combined suicide gene system. Human BxPC-3 pancreatic cells secreting the carcinoembryonic antigen (CEA) tumor marker were injected into the peritoneal cavity of nude mice. After 8 days, intraperitoneal (i.p.) lipofection was performed using BGTC/DOPE cationic liposomes complexed with plasmids encoding the two prodrug-activating enzymes Herpes Simplex Virus thymidine kinase and Escherichia coli cytosine deaminase, the latter being expressed from a bicistronic cassette also encoding E. coli uracil phosphoribosyltransferase. Administration of the lipoplexes was followed by treatment with the corresponding prodrugs ganciclovir and 5-fluorocytosine. The results presented herein demonstrate that BGTC/DOPE liposomes can efficiently mediate gene transfection into peritoneal tumor nodules. Indeed, HSV-TK mRNA was detected in tumor nodule tissues by semiquantitative reverse transcription-polymerase chain reaction analysis. In addition, green fluorescent protein (GFP) fluorescence and X-gal staining were observed in the peritoneal tumor foci following lipofection of the corresponding EGFP and LacZ reporter genes. These expression analyses also showed that transgene expression lasted for about 2 weeks and was preferential for the tumor nodules, this tumor preference being in good agreement with the absence of obvious treatment-related toxicity. Most importantly, mice receiving the full treatment scheme (BGTC liposomes, suicide genes and prodrugs) had significantly lower serum CEA levels than those of the various control groups, a finding indicating that peritoneal carcinomatosis progression was strongly reduced in these mice. In conclusion, our results demonstrate the therapeutic efficiency of BGTC-mediated i.p. lipofection of a combined suicide gene system in a mouse peritoneal carcinomatosis model and suggest that BGTC-based prodrug-activating gene therapy approaches may constitute a potential treatment modality for patients with peritoneal carcinomatosis and minimal residual disease.
authors.affiliation: INSERM U375, IRCAD, 1 place de l'Hôpital, BP 426, 67091 Strasbourg, France. amor.hajri@ircad.u-strasbg.fr
authors.forename: Amor
authors.initials: A
authors.lastname: Hajri
authors.forename: Séverine
authors.initials: S
authors.lastname: Wack
authors.forename: Pierre
authors.initials: P
authors.lastname: Lehn
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Vigneron
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Lehn
authors.forename: Jacques
authors.initials: J
authors.lastname: Marescaux
authors.forename: Marc
authors.initials: M
authors.lastname: Aprahamian
mesh_terms: D000818:Animals; D001706:Biopsy; D002272:Carcinoembryonic Antigen / Q000032:analysis; D002455:Cell Division / Q000187:drug effects; D045744:Cell Line, Tumor; D002784:Cholesterol / Q000031:analogs & derivatives*; D043525:Cytosine Deaminase / Q000235:genetics / Q000378:metabolism; D018450:Disease Progression; D004926:Escherichia coli; D005260:Female; D005437:Flucytosine / Q000494:pharmacology / Q000627:therapeutic use; D015774:Ganciclovir / Q000494:pharmacology / Q000627:therapeutic use; D041722:Genes, Transgenic, Suicide / Q000235:genetics*; D015316:Genetic Therapy / Q000379:methods*; D006146:Guanidines; D006801:Humans; D008081:Liposomes / Q000008:administration & dosage* / Q000737:chemistry; D051379:Mice; D008819:Mice, Nude; D010190:Pancreatic Neoplasms / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology / Q000628:therapy*; D010529:Peritoneal Cavity / Q000473:pathology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018139:Simplexvirus / Q000201:enzymology / Q000235:genetics; D013937:Thymidine Kinase / Q000235:genetics / Q000378:metabolism; D014162:Transfection
chemical_list: C101389:3-(N(4)-(N(1),N(8)-diguanidinospermidine)carbamoyl)cholesterol; D002272:Carcinoembryonic Antigen; D006146:Guanidines; D008081:Liposomes; D012333:RNA, Messenger; D002784:Cholesterol; D005437:Flucytosine; D013937:Thymidine Kinase; D043525:Cytosine Deaminase; D015774:Ganciclovir