Small Interfering RNA Expression Vector Targeting Hypoxia-Inducible Factor 1 Alpha Inhibits Tumor Growth in Hepatobiliary and Pancreatic Cancers

Cancer Gene Ther. 2006 Feb;13(2):131-40. doi: 10.1038/sj.cgt.7700871.

Abstract

Hepatobiliary and pancreatic carcinomas are hypovascular tumors that can proliferate under hypoxic conditions. Recent reports have demonstrated that hypoxia-inducible factor 1 alpha (HIF1alpha) plays an important role in the survival of these cancers. Given these findings, the inhibition of the HIF1alpha pathway might prove to be a powerful tool in the treatment of these cancers. To inhibit HIF1alpha expression, we used small interference RNA (siRNA) expression vectors in this study. The transient transfection of siRNA expression vectors significantly reduced both HIF1alpha mRNA levels (13% of control) and protein levels (41% of control) and significantly inhibited the growth of cancer cell lines (P<0.05). VEGF, Glut1, and aldorase A expressions were also significantly reduced by transfection with these vectors (P<0.05), and we found that these vectors induced apoptosis but not cell cycle arrest. In a subcutaneous tumor model using nude mice, transfected MIA PaCa-2 cells, stably expressing siRNAs, barely formed tumors compared to control (P<0.05). This study thus demonstrates the usefulness of siRNA expression vector in targeting HIF1alpha and points to a potential clinical role in the treatment of pancreatic and hepatobiliary carcinomas.

Publication types

  • Comparative Study

MeSH terms

  • Animals
  • Biliary Tract Neoplasms / therapy*
  • Blotting, Northern
  • Blotting, Western
  • Cell Line, Tumor
  • DNA Primers
  • Gene Expression Regulation, Neoplastic*
  • Genetic Therapy / methods*
  • Genetic Vectors / therapeutic use*
  • Glucose Transporter Type 1 / metabolism
  • Humans
  • Hypoxia-Inducible Factor 1, alpha Subunit / metabolism*
  • Immunohistochemistry
  • In Situ Nick-End Labeling
  • Liver Neoplasms / therapy*
  • Mice
  • Mice, Nude
  • Microscopy, Fluorescence
  • Pancreatic Neoplasms / therapy*
  • RNA, Small Interfering / metabolism
  • RNA, Small Interfering / therapeutic use*
  • Tumor Stem Cell Assay
  • Vascular Endothelial Growth Factor A / metabolism

Substances

  • DNA Primers
  • Glucose Transporter Type 1
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • RNA, Small Interfering
  • SLC2A1 protein, human
  • Vascular Endothelial Growth Factor A