Inhibition of hedgehog signaling depresses self-renewal of pancreatic cancer stem cells and reverses chemoresistance

Int J Oncol. 2012 Nov;41(5):1707-14. doi: 10.3892/ijo.2012.1597. Epub 2012 Aug 22.

Abstract

Pancreatic cancer stem cells play a crucial role in tumorigenesis and chemoresistance. The Hedgehog signaling pathway is a key regulator in pancreatic tumorigenesis and drug resistance. To identify pancreatic cancer stem cells, tumorspheres derived from the PANC-1 pancreatic cancer cell line were cultured under a floating-culture system. PANC-1 tumorspheres possessed properties of self-renewal, differentiation, higher tumorigenesis and chemoresistance. It was observed that Hedgehog pathway is active in PANC-1 tumorspheres as shown by expression of hedgehog components Smo, Gil 1 and Gli 2, detected by quantitative RT-PCR and western blotting. After cyclopamine-mediated blockade of hedgehog, a decrease in proliferation of PANC-1 tumorspheres and G0/G1 transition were observed, as well as a decreased expression of Bmi-1 in PANC-1 tumorspheres. Cyclopamine reversed chemoresistance to gemcitabine, resulting in decreased expression of ABCG2 in PANC-1 tumorspheres. Taken together, our data indicate that PANC-1 tumorspheres have 'stemness' potential, and hedgehog signaling pathway plays an important role in the regulation of self-renewal and reversal of chemoresistance in cancer stem cells in pancreatic adenocarcinoma.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • AC133 Antigen
  • Animals
  • Antigens, CD / genetics
  • Antigens, CD / metabolism
  • Cell Differentiation
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Cell Transformation, Neoplastic / metabolism
  • Drug Resistance, Neoplasm* / drug effects
  • Drug Resistance, Neoplasm* / genetics
  • Glycoproteins / genetics
  • Glycoproteins / metabolism
  • Hedgehog Proteins / genetics
  • Hedgehog Proteins / metabolism*
  • Humans
  • Mice
  • Mice, Inbred NOD
  • Mice, SCID
  • Neoplastic Stem Cells / metabolism*
  • Neoplastic Stem Cells / pathology
  • Pancreatic Neoplasms / genetics
  • Pancreatic Neoplasms / metabolism*
  • Pancreatic Neoplasms / pathology
  • Peptides / genetics
  • Peptides / metabolism
  • Signal Transduction* / drug effects
  • Spheroids, Cellular
  • Tumor Cells, Cultured
  • Veratrum Alkaloids / pharmacology

Substances

  • AC133 Antigen
  • Antigens, CD
  • Glycoproteins
  • Hedgehog Proteins
  • Peptides
  • Veratrum Alkaloids
  • cyclopamine