title: Environmentally controlled invasion of cancer cells by engineered bacteria.
abstract: Bacteria can sense their environment, distinguish between cell types, and deliver proteins to eukaryotic cells. Here, we engineer the interaction between bacteria and cancer cells to depend on heterologous environmental signals. We have characterized invasin from Yersinia pseudotuburculosis as an output module that enables Escherichia coli to invade cancer-derived cells, including HeLa, HepG2, and U2OS lines. To environmentally restrict invasion, we placed this module under the control of heterologous sensors. With the Vibrio fischeri lux quorum sensing circuit, the hypoxia-responsive fdhF promoter, or the arabinose-inducible araBAD promoter, the bacteria invade cells at densities greater than 10(8)bacteria/ml, after growth in an anaerobic growth chamber or in the presence of 0.02% arabinose, respectively. In the process, we developed a technique to tune the linkage between a sensor and output gene using ribosome binding site libraries and genetic selection. This approach could be used to engineer bacteria to sense the microenvironment of a tumor and respond by invading cancerous cells and releasing a cytotoxic agent.
authors.affiliation: Howard Hughes Medical Institute, California Institute of Quantitative Biology Department of Bioengineering, University of California, 717 Potter Street, Room 257 Berkeley, CA 94720, USA.
authors.forename: J Christopher
authors.initials: JC
authors.lastname: Anderson
authors.forename: Elizabeth J
authors.initials: EJ
authors.lastname: Clarke
authors.forename: Adam P
authors.initials: AP
authors.lastname: Arkin
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Voigt
mesh_terms: D018829:Adhesins, Bacterial / Q000235:genetics* / Q000378:metabolism*; D048908:Aliivibrio fischeri / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics; D001483:Base Sequence; D002452:Cell Count; D015687:Cell Hypoxia / Q000502:physiology; D045744:Cell Line, Tumor; D004926:Escherichia coli / Q000502:physiology*; D005786:Gene Expression Regulation; D005818:Genetic Engineering; D005822:Genetic Vectors / Q000235:genetics; D006801:Humans; D009369:Neoplasms / Q000382:microbiology / Q000473:pathology* / Q000628:therapy*; D011401:Promoter Regions, Genetic / Q000235:genetics; D015011:Yersinia pseudotuberculosis / Q000235:genetics / Q000378:metabolism
chemical_list: D018829:Adhesins, Bacterial; D001426:Bacterial Proteins; C053476:invasin, Yersinia