title: 5-Fluorouracil-loaded poly(ε-caprolactone) nanoparticles combined with phage E gene therapy as a new strategy against colon cancer.
abstract: This work aimed to develop a new therapeutic approach to increase the efficacy of 5-fluorouracil (5-FU) in the treatment of advanced or recurrent colon cancer. 5-FU-loaded biodegradable poly(ε-caprolactone) nanoparticles (PCL NPs) were combined with the cytotoxic suicide gene E (combined therapy). The SW480 human cancer cell line was used to assay the combined therapeutic strategy. This cell line was established from a primary adenocarcinoma of the colon and is characterized by an intrinsically high resistance to apoptosis that correlates with its resistance to 5-FU. 5-FU was absorbed into the matrix of the PCL NPs during synthesis using the interfacial polymer disposition method. The antitumor activity of gene E from the phage ϕX174 was tested by generating a stable clone (SW480/12/E). In addition, the localization of E protein and its activity in mitochondria were analyzed. We found that the incorporation of 5-FU into PCL NPs (which show no cytotoxicity alone), significantly improved the drug's anticancer activity, reducing the proliferation rate of colon cancer cells by up to 40-fold when compared with the nonincorporated drug alone. Furthermore, E gene expression sensitized colon cancer cells to the cytotoxic action of the 5-FU-based nanomedicine. Our findings demonstrate that despite the inherent resistance of SW480 to apoptosis, E gene activity is mediated by an apoptotic phenomenon that includes modulation of caspase-9 and caspase-3 expression and intense mitochondrial damage. Finally, a strongly synergistic antiproliferative effect was observed in colon cancer cells when E gene expression was combined with the activity of the 5-FU-loaded PCL NPs, thereby indicating the potential therapeutic value of the combined therapy.
authors.affiliation: Institute of Biopathology and Regenerative Medicine (IBIMER), University of Granada, Granada, Spain.
authors.forename: Raúl
authors.initials: R
authors.lastname: Ortiz
authors.forename: José
authors.initials: J
authors.lastname: Prados
authors.forename: Consolación
authors.initials: C
authors.lastname: Melguizo
authors.forename: José L
authors.initials: JL
authors.lastname: Arias
authors.forename: M Adolfina
authors.initials: MA
authors.lastname: Ruiz
authors.forename: Pablo J
authors.initials: PJ
authors.lastname: Alvarez
authors.forename: Octavio
authors.initials: O
authors.lastname: Caba
authors.forename: Raquel
authors.initials: R
authors.lastname: Luque
authors.forename: Ana
authors.initials: A
authors.lastname: Segura
authors.forename: Antonia
authors.initials: A
authors.lastname: Aránega
mesh_terms: D000964:Antimetabolites, Antineoplastic / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D003110:Colonic Neoplasms / Q000188:drug therapy / Q000235:genetics / Q000473:pathology / Q000628:therapy*; D004337:Drug Carriers / Q000737:chemistry; D005472:Fluorouracil / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology*; D015316:Genetic Therapy / Q000379:methods*; D006801:Humans; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D053758:Nanoparticles / Q000737:chemistry*; D011091:Polyesters / Q000737:chemistry / Q000494:pharmacology*; D014764:Viral Proteins / Q000008:administration & dosage / Q000235:genetics* / Q000378:metabolism
chemical_list: D000964:Antimetabolites, Antineoplastic; D004337:Drug Carriers; C029555:E protein, bacteriophage X174; D011091:Polyesters; D014764:Viral Proteins; C016240:polycaprolactone; D005472:Fluorouracil