title: 'Obligate' anaerobicSalmonellastrain YB1 suppresses liver tumor growth and metastasis in nude mice.
abstract: The antitumor properties of bacteria have been demonstrated over the past decades. However, the efficacy is limited and unclear. Furthermore, systemic infection remains a serious concern in bacteria treatment. In this study, the effect of YB1, a rationally designed 'obligate' anaerobicSalmonellatyphimurium strain, on liver tumor growth and metastasis in a nude mouse orthotopic liver tumor model was investigated. The orthotopic liver tumor model was established in nude mice using the hepatocellular carcinoma cell line MHCC-97L. Two weeks after orthotopic liver tumor implantation, YB1, SL7207 and saline were respectively administered through the tail vein of the mice. Longitudinal monitoring of tumor growth and metastasis was performed using Xenogen IVIS, and direct measurements of tumor volume were taken 3 weeks after treatment.In vitro, MHCC-97L and PLC cells were incubated with YB1 or SL7207 under anaerobic conditions. YB1 was observed to invade tumor cells and induce tumor cell apoptosis and death. The results revealed that all mice in the YB1 group were alive 3 weeks after YB1 injection while all mice in the SL7207 group died within 11 days of the SL7207 injection. The body weight decreased by ~9% on day 1 after YB1 injection and but subsequently recovered. Liver tumor growth and metastases were significantly inhibited following YB1 treatment. By contrast to the control group, a large number of Gr1-positive cells were detected on days 1 to 21 following YB1 treatment. Furthermore, YB1 also effectively invaded tumor cells and induced tumor cell apoptosis and death. In conclusion, YB1 suppressed liver tumor growth and metastasis in a nude mice liver tumor model. The potential mechanism may be through enhancing innate immune response and inducing tumor cell apoptosis and cell death.
authors.affiliation: Department of Surgery and Centre for Cancer Research, University of Hong Kong, Hong Kong 999077, SAR, P.R. China.
authors.forename: Chang-Xian
authors.initials: CX
authors.lastname: Li
authors.affiliation: Department of Biochemistry and Shenzhen Institute of Research and Innovation, University of Hong Kong, Hong Kong 999077, SAR, P.R. China; Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong College of Optoelectronic Engineering, Shenzhen University, Shenzhen, Guangdong 518060, P.R. China.
authors.forename: Bin
authors.initials: B
authors.lastname: Yu
authors.affiliation: Department of Biochemistry and Shenzhen Institute of Research and Innovation, University of Hong Kong, Hong Kong 999077, SAR, P.R. China.
authors.forename: Lei
authors.initials: L
authors.lastname: Shi
authors.affiliation: Department of Surgery and Centre for Cancer Research, University of Hong Kong, Hong Kong 999077, SAR, P.R. China.
authors.forename: Wei
authors.initials: W
authors.lastname: Geng
authors.affiliation: Department of Biochemistry and Shenzhen Institute of Research and Innovation, University of Hong Kong, Hong Kong 999077, SAR, P.R. China.
authors.forename: Qiu-Bin
authors.initials: QB
authors.lastname: Lin
authors.affiliation: Department of Surgery and Centre for Cancer Research, University of Hong Kong, Hong Kong 999077, SAR, P.R. China.
authors.forename: Chang-Chun
authors.initials: CC
authors.lastname: Ling
authors.affiliation: Department of Biochemistry and Shenzhen Institute of Research and Innovation, University of Hong Kong, Hong Kong 999077, SAR, P.R. China.
authors.forename: Mei
authors.initials: M
authors.lastname: Yang
authors.affiliation: Department of Surgery and Centre for Cancer Research, University of Hong Kong, Hong Kong 999077, SAR, P.R. China.
authors.forename: Kevin T P
authors.initials: KT
authors.lastname: Ng
authors.affiliation: Department of Biochemistry and Shenzhen Institute of Research and Innovation, University of Hong Kong, Hong Kong 999077, SAR, P.R. China; Centre for Synthetic Biology Engineering Research, Shenzhen Institutes of Advanced Technology, Shenzhen, Guangdong 518055, P.R. China.
authors.forename: Jian-Dong
authors.initials: JD
authors.lastname: Huang
authors.affiliation: Department of Surgery and Centre for Cancer Research, University of Hong Kong, Hong Kong 999077, SAR, P.R. China.
authors.forename: Kwan
authors.initials: K
authors.lastname: Man
keywords: YB1; apoptosis; hepatocellular carcinoma; immune response; metastasis; tumor growth