title: EpCAM-targeted liposomal si-RNA delivery for treatment of epithelial cancer.
abstract: BACKGROUND
  RNA interference (RNAi) technology using short interfering RNA (si-RNA) has shown immense potential in the treatment of cancers through silencing of specific genes. Cationic non-viral vectors employed for gene delivery exhibit toxic effects in normal cells limiting their widespread use, therefore, site-specific delivery using benign carriers could address this issue.
  
  
  OBJECTIVE
  Design of a non-toxic carrier that enables site-specific delivery of si-RNA into the cancer cells is of prime importance to realize the promise of gene silencing.
  
  
  METHODS
  In the present study, non-cationic liposomes encapsulating si-RNA against epithelial cell adhesion molecule (EpCAM) were developed and characterized for encapsulation efficiency, colloidal stability, in vitro and in vivo gene silencing efficacy.
  
  
  RESULTS
  PEGylated liposomes containing phosphatidyl choline and phosphatidyl ethanolamine exhibited maximum si-RNA encapsulation efficiency of 47%, zeta potential of -21 mV, phase transition temperature of 51 °C and good colloidal stability in phosphate-buffered saline (PBS) containing bovine serum albumin (BSA) and plasma protein (PP) at 37 °C. Conjugation of epithelial cell adhesion molecule (EpCAM) antibody to the liposomes resulted in enhanced cell internalization and superior down-regulation of EpCAM gene in MCF-7 cell lines when compared with free si-RNA and the non-targeted liposomes. In vivo evaluation of immunoliposomes for their efficacy in regressing the tumor volume in Balb/c SCID mice showed about 35% reduction of tumor volume in comparison with the positive control when administered with an extremely low dose of 0.15 mg/kg twice a week for 4 weeks.
  
  
  CONCLUSIONS
  Our results exhibit that the nanocarrier-mediated silencing of EpCAM gene is a promising strategy to treat epithelial cancers.
authors.affiliation: a Centre for Nanotechnology & Advanced Biomaterials, School of Chemical & Biotechnology , SASTRA University , Thanjavur , India and.
authors.forename: Dhiraj
authors.initials: D
authors.lastname: Bhavsar
authors.affiliation: b L&T Ophthalmic Pathology Department, Sankara Nethralaya , Vision Research Foundation , Chennai , India.
authors.forename: Krishnakumar
authors.initials: K
authors.lastname: Subramanian
authors.affiliation: a Centre for Nanotechnology & Advanced Biomaterials, School of Chemical & Biotechnology , SASTRA University , Thanjavur , India and.
authors.forename: Swaminathan
authors.initials: S
authors.lastname: Sethuraman
authors.affiliation: a Centre for Nanotechnology & Advanced Biomaterials, School of Chemical & Biotechnology , SASTRA University , Thanjavur , India and.
authors.forename: Uma Maheswari
authors.initials: UM
authors.lastname: Krishnan
mesh_terms: D000818:Animals; D000912:Antibodies, Neoplasm / Q000737:chemistry* / Q000276:immunology; D045744:Cell Line, Tumor; D000071858:Epithelial Cell Adhesion Molecule / Q000737:chemistry* / Q000378:metabolism; D020868:Gene Silencing / Q000502:physiology*; D018014:Gene Transfer Techniques; D015316:Genetic Therapy / Q000379:methods; D006801:Humans; D008081:Liposomes; D061986:MCF-7 Cells; D051379:Mice; D016513:Mice, SCID; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000008:administration & dosage* / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism
chemical_list: D000912:Antibodies, Neoplasm; D000071858:Epithelial Cell Adhesion Molecule; D008081:Liposomes; D034741:RNA, Small Interfering
keywords: Colloidal stability; gene delivery; gene silencing; non-cationic liposomes; release kinetics