Vitamin E δ-tocotrienol prolongs survival in the LSL-KrasG12D/+;LSL-Trp53R172H/+;Pdx-1-Cre (KPC) transgenic mouse model of pancreatic cancer

Cancer Prev Res (Phila). 2013 Oct;6(10):1074-83. doi: 10.1158/1940-6207.CAPR-13-0157. Epub 2013 Aug 20.

Abstract

Previous work has shown that vitamin E δ-tocotrienol (VEDT) prolongs survival and delays progression of pancreatic cancer in the LSL-Kras(G12D)(/+);Pdx-1-Cre mouse model of pancreatic cancer. However, the effect of VEDT alone or in combination with gemcitabine in the more aggressive LSL-Kras(G12D)(/+);LSL-Trp53(R172H)(/+);Pdx-1-Cre (KPC) mouse model is unknown. Here, we studied the effects of VEDT and the combination of VEDT and gemcitabine in the KPC mice. KPC mice were randomized into four groups: (i) vehicle [olive oil, 1.0 mL/kg per os twice a day and PBS 1.0 mL/kg intrapertoneally (i.p.) twice a week], (ii) gemcitabine (100 mg/kg i.p. twice a week), (iii) VEDT (200 mg/kg per os twice a day), and (iv) gemcitabine + VEDT. Mice received treatment until they displayed symptoms of impending death from pancreatic cancer, at which point animals were euthanized. At 16 weeks, survival was 10% in the vehicle group, 30% in the gemcitabine group, 70% in the VEDT group (P < 0.01), and 90% in the VEDT combined with gemcitabine group (P < 0.05). VEDT alone and combined with gemcitabine resulted in reversal of epithelial-to-mesenchymal transition in tumors. Biomarkers of apoptosis (plasma CK18), PARP1 cleavage, and Bax expression were more greatly induced in tumors subjected to combined treatment versus individual treatment. Combined treatment induced cell-cycle inhibitors (p27(Kip1) and p21(Cip1)) and inhibited VEGF, vascularity (CD31), and oncogenic signaling (pAKT, pMEK, and pERK) greater than individual drugs. No significant differences in body weight gain between drug treatment and control mice were observed. These results strongly support further investigation of VEDT alone and in combination with gemcitabine for pancreatic cancer prevention and treatment.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Apoptosis
  • Biomarkers, Tumor
  • Body Weight
  • Cell Proliferation
  • Cyclin-Dependent Kinase Inhibitor p21 / metabolism
  • Cyclin-Dependent Kinase Inhibitor p27 / metabolism
  • Deoxycytidine / analogs & derivatives*
  • Deoxycytidine / pharmacology
  • Disease Models, Animal
  • Drug Therapy, Combination
  • Enzyme-Linked Immunosorbent Assay
  • Epithelial-Mesenchymal Transition
  • Female
  • Genes, ras
  • Genotype
  • Immunohistochemistry
  • Male
  • Mice
  • Mice, Transgenic
  • Pancreatic Neoplasms / genetics*
  • Pancreatic Neoplasms / mortality
  • Pancreatic Neoplasms / therapy
  • Platelet Endothelial Cell Adhesion Molecule-1 / metabolism
  • Poly(ADP-ribose) Polymerases / metabolism
  • Random Allocation
  • Signal Transduction
  • Treatment Outcome
  • Vitamin E / analogs & derivatives*
  • Vitamin E / pharmacology
  • bcl-2-Associated X Protein / metabolism

Substances

  • Biomarkers, Tumor
  • Cdkn1a protein, mouse
  • Cdkn1b protein, mouse
  • Cyclin-Dependent Kinase Inhibitor p21
  • Platelet Endothelial Cell Adhesion Molecule-1
  • bcl-2-Associated X Protein
  • Deoxycytidine
  • Vitamin E
  • Cyclin-Dependent Kinase Inhibitor p27
  • tocotrienol, delta
  • gemcitabine
  • Poly(ADP-ribose) Polymerases