Overexpression of fatty acid synthase in Middle Eastern epithelial ovarian carcinoma activates AKT and Its inhibition potentiates cisplatin-induced apoptosis

Mol Med. 2011;17(7-8):635-45. doi: 10.2119/molmed.2011.00046. Epub 2011 Mar 21.

Abstract

Fatty acid synthase (FASN), the enzyme responsible for de novo synthesis of fatty acids, has been shown to be deregulated in several cancers, including epithelial ovarian carcinoma (EOC). In this study, we investigated the function of the FASN signaling pathway in a large series of Middle Eastern EOC patient samples, a panel of cell lines and nude mouse model. Using immunohistochemistry, we detected overexpression of FASN in 75.5% (114/151) of the tumor samples. Overexpression of FASN was associated significantly with tumor proliferative marker Ki-67 (P = 0.0009), activated AKT (P = 0.0117) and XIAP (P = 0.0046). Treatment of EOC cell lines with C-75, a selective inhibitor of FASN, caused inhibition of EOC cell viability via induction of apoptosis. Inhibition of FASN by C-75 led apoptosis via the mitochondrial pathway. FASN inhibition caused downregulation of activated AKT and its downstream targets. In addition, inhibition by FASN siRNA caused downregulation of FASN and activation of caspases, suggesting the role of FASN in C-75 mediated apoptosis. Furthermore, treatment of EOC cells with subtoxic doses of C-75 augmented the effect of cisplatin-mediated induction of apoptosis. Finally, treatment of EOC cell line xenografts with a combination of C-75 and cisplatin resulted in growth inhibition of tumors in nude mice through downregulation of FASN and activation of caspases. Altogether, our results show overexpression of FASN in Middle Eastern EOC, suggesting that FASN may be a potential therapeutic target in a subset of EOC, alone or in combination with other conventional chemotherapeutic agents.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 4-Butyrolactone / administration & dosage
  • 4-Butyrolactone / analogs & derivatives
  • 4-Butyrolactone / pharmacology
  • Adult
  • Aged
  • Aged, 80 and over
  • Animals
  • Antineoplastic Agents / administration & dosage
  • Antineoplastic Agents / pharmacology
  • Antineoplastic Combined Chemotherapy Protocols / therapeutic use
  • Apoptosis / drug effects*
  • Carcinoma, Ovarian Epithelial
  • Cisplatin / administration & dosage
  • Cisplatin / pharmacology*
  • Drug Synergism
  • Fatty Acid Synthases / antagonists & inhibitors
  • Fatty Acid Synthases / genetics
  • Fatty Acid Synthases / metabolism*
  • Female
  • Humans
  • Immunohistochemistry
  • Mice
  • Mice, Nude
  • Middle Aged
  • Middle East
  • Neoplasms, Glandular and Epithelial / drug therapy
  • Neoplasms, Glandular and Epithelial / metabolism*
  • Neoplasms, Glandular and Epithelial / pathology
  • Ovarian Neoplasms / drug therapy
  • Ovarian Neoplasms / metabolism*
  • Ovarian Neoplasms / pathology
  • Proto-Oncogene Proteins c-akt / metabolism*
  • RNA Interference
  • Tissue Array Analysis
  • Xenograft Model Antitumor Assays
  • Young Adult

Substances

  • 4-methylene-2-octyl-5-oxofuran-3-carboxylic acid
  • Antineoplastic Agents
  • Fatty Acid Synthases
  • Proto-Oncogene Proteins c-akt
  • 4-Butyrolactone
  • Cisplatin