title: Effect of ultrasound irradiation on bacterial internalization and bacteria-mediated gene transfer to cancer cells.
abstract: The present study demonstrates that ultrasound irradiation can facilitate bacteria-mediated gene delivery (bactofection). Escherichia coli modified with avidin were employed as a vehicle for delivery of the green fluorescent protein (GFP) gene, a model heterologous gene, into the breast cancer cell line MCF-7. Avidin-mediated binding of E. coli to MCF-7 cells enhanced the internalization of E. coli by approximately 17%, irrespective of the use of ultrasound irradiation. Furthermore, the use of ultrasound irradiation increased the internalization by approximately 5%, irrespective of the presence of avidin on the E. coli cell surface. The percentages of GFP-expressing MCF-7 cells at 24h after bactofection were below 0.5% and 2% for the case with only avidin-modification of E. coli cell surface and only ultrasound irradiation, respectively. However, combining avidin modification with the ultrasound treatment increased this value to 8%. Thus, the use of avidin-modified bacteria in conjunction with ultrasound irradiation has potential as an effective strategy for tumor-targeted bactofection.
authors.affiliation: Institute of Nature and Environmental Technology, Kanazawa University, Kanazawa 920-1192, Japan.
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Ninomiya
authors.affiliation: Division of Natural System, Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa 920-1192, Japan.
authors.forename: Ryuji
authors.initials: R
authors.lastname: Yamada
authors.affiliation: Division of Natural System, Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa 920-1192, Japan.
authors.forename: Hitomi
authors.initials: H
authors.lastname: Meisaku
authors.affiliation: Institute of Nature and Environmental Technology, Kanazawa University, Kanazawa 920-1192, Japan. Electronic address: nshimizu@t.kanazawa-u.ac.jp.
authors.forename: Nobuaki
authors.initials: N
authors.lastname: Shimizu
mesh_terms: D001360:Avidin / Q000378:metabolism; D045744:Cell Line, Tumor; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000235:genetics; D006801:Humans; D061986:MCF-7 Cells; D010957:Plasmids / Q000235:genetics; D014162:Transfection / Q000379:methods*; D014465:Ultrasonics
chemical_list: D001360:Avidin; D049452:Green Fluorescent Proteins
keywords: Avidin; Bactofection; Cancer cells; Escherichia coli; Gene therapy; Ultrasound irradiation