Antitumoral activity of rapamycin mediated through inhibition of HIF-1alpha and VEGF in hepatocellular carcinoma

Dig Dis Sci. 2009 Oct;54(10):2128-36. doi: 10.1007/s10620-008-0605-3. Epub 2008 Dec 4.

Abstract

Rapamycin (RAPA) inhibits tumor growth and angiogenesis in hepatocellular carcinoma (HCC). The molecular mechanism underlying the antitumoral effects of RAPA remains unclear. Here we established a chemical-induced rat HCC model to investigate the signaling pathways mediating RAPA's antitumor activity. We found that RAPA exposure significantly diminished tumor growth, angiogenesis, and metastasis of HCC. Meanwhile, the antitumor drug dramatically decreased expression of HIF-1alpha and VEGF, either at mRNA or protein levels. Moreover, the low-dose of RAPA (1.5 mg/kg/day) was effective enough to markedly inhibit tumor progression of HCC. The preliminary results suggested that the antitumoral effects of RAPA might be at least partially mediated through downregulation of HIF-1alpha and VEGF, and low-dose RAPA-based regimens exhibited a promising future in treatment of HCC.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibiotics, Antineoplastic / pharmacology*
  • Antibiotics, Antineoplastic / therapeutic use
  • Blotting, Western
  • Carcinoma, Hepatocellular / drug therapy*
  • Enzyme-Linked Immunosorbent Assay
  • Hypoxia-Inducible Factor 1, alpha Subunit / antagonists & inhibitors*
  • Immunohistochemistry
  • Liver Neoplasms, Experimental / drug therapy*
  • Male
  • Neovascularization, Pathologic / drug therapy
  • Rats
  • Rats, Sprague-Dawley
  • Reverse Transcriptase Polymerase Chain Reaction
  • Signal Transduction
  • Sirolimus / pharmacology*
  • Sirolimus / therapeutic use
  • Vascular Endothelial Growth Factor A / antagonists & inhibitors*

Substances

  • Antibiotics, Antineoplastic
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • Vascular Endothelial Growth Factor A
  • Sirolimus