Targeted therapy via oral administration of attenuated Salmonella expression plasmid-vectored Stat3-shRNA cures orthotopically transplanted mouse HCC

Cancer Gene Ther. 2012 Jun;19(6):393-401. doi: 10.1038/cgt.2012.12. Epub 2012 May 4.

Abstract

The development of RNA interference-based cancer gene therapies has been delayed due to the lack of effective tumor-targeting delivery systems. Attenuated Salmonella enterica serovar Typhimurium (S. Typhimurium) has a natural tropism for solid tumors. We report here the use of attenuated S. Typhimurium as a vector to deliver shRNA directly into tumor cells. Constitutively activated signal transducer and activator of transcription 3 (Stat3) is a key transcription factor involved in both hepatocellular carcinoma (HCC) growth and metastasis. In this study, attenuated S. Typhimurium was capable of delivering shRNA-expressing vectors to the targeted cancer cells and inducing RNA interference in vivo. More importantly, a single oral dose of attenuated S. Typhimurium carrying shRNA-expressing vectors targeting Stat3 induced remarkably delayed and reduced HCC (in 70% of mice). Cancer in these cured mice did not recur over 2 years following treatment. These data demonstrated that RNA interference combined with Salmonella as a delivery system may offer a novel clinical approach for cancer gene therapy.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis
  • Carcinoma, Hepatocellular / immunology
  • Carcinoma, Hepatocellular / metabolism
  • Carcinoma, Hepatocellular / pathology
  • Carcinoma, Hepatocellular / therapy*
  • Cell Proliferation
  • Cell Survival
  • Cytotoxicity, Immunologic
  • G1 Phase Cell Cycle Checkpoints
  • Gene Expression Profiling
  • Gene Knockdown Techniques
  • Genetic Therapy
  • Genetic Vectors
  • Green Fluorescent Proteins / biosynthesis
  • Green Fluorescent Proteins / genetics
  • Killer Cells, Natural / immunology
  • Killer Cells, Natural / physiology
  • Liver Neoplasms / immunology
  • Liver Neoplasms / metabolism
  • Liver Neoplasms / pathology
  • Liver Neoplasms / therapy*
  • Mice
  • Mice, Inbred C57BL
  • Neoplasm Transplantation
  • Plasmids
  • RNA Interference
  • RNA, Small Interfering / genetics*
  • Recombinant Proteins / biosynthesis
  • Recombinant Proteins / genetics
  • STAT3 Transcription Factor / genetics*
  • STAT3 Transcription Factor / metabolism
  • Salmonella typhimurium / genetics*
  • T-Lymphocytes, Cytotoxic / immunology
  • T-Lymphocytes, Cytotoxic / physiology
  • Tumor Burden

Substances

  • RNA, Small Interfering
  • Recombinant Proteins
  • STAT3 Transcription Factor
  • STAT3 protein, human
  • Green Fluorescent Proteins