Cytotoxicity and radiosensitizing activity of the fatty acid synthase inhibitor C75 is enhanced by blocking fatty acid uptake in prostate cancer cells

Rae, C. , Fragkoulis, G. I. and Chalmers, A. J. (2020) Cytotoxicity and radiosensitizing activity of the fatty acid synthase inhibitor C75 is enhanced by blocking fatty acid uptake in prostate cancer cells. Advances in Radiation Oncology, 5(5), pp. 944-1005. (doi: 10.1016/j.adro.2020.06.022) (PMID:33083663) (PMCID:PMC7557210)

Abstract

Prostate cancers, like many other types of cancer, express elevated levels of fatty acid synthase (FASN) to make more fatty acids, which are required for energy, signaling, and proliferation. Because inhibition of FASN has been shown to sensitize tumors to chemotherapy and radiation, we studied the effect of C75, a radiosensitizing FASN inhibitor, and compared its single agent and radiosensitizing activities in 2 prostate cancer cell lines, PC3 and LNCaP, with alternative FASN inhibitors that have progressed into clinical trials. We also investigated the effect of serum and fatty acid supplementation on responses to FASN inhibitors, probing expression of key proteins related to fatty acid uptake in response to FASN inhibition, irradiation, and serum lipid concentration and how this may be modulated to increase the potency of C75. We demonstrated that C75 was the only FASN inhibitor to sensitize cells to ionizing radiation; no sensitization was apparent with FASN inhibitors TVB-3166 or Orlistat. The prostate cancer cell lines were able to take up fatty acids from the culture medium, and the availability of fatty acids affected sensitivity of these cells to C75 but not the other FASN inhibitors tested. C75 also increased expression of fatty acid transporter proteins FATP1 and CD36. Furthermore, blocking CD36 with antibody increased the sensitivity of cells to C75. We suggest that the potency of C75 is affected by fatty acid availability and that the effectiveness of FASN inhibitors in combination with ionizing radiation can be further enhanced by regulating fatty acid uptake.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Fragkoulis, Dr Georgios and Chalmers, Professor Anthony and Rae, Dr Colin
• Authors: Rae, C., Fragkoulis, G. I., and Chalmers, A. J.
• College/School: College of Medical Veterinary and Life Sciences > School of Cancer Sciences; College of Medical Veterinary and Life Sciences > School of Infection & Immunity
• Journal Name: Advances in Radiation Oncology
• Publisher: Elsevier
• ISSN: 2452-1094
• ISSN (Online): 2452-1094
• Published Online: 29 June 2020
• Copyright Holders: Copyright © 2020 The Authors
• First Published: First published in Advances in Radiation Oncology 5(5): 994-1005
• Publisher Policy: Reproduced under a Creative Commons licence

Project Code	Award No	Project Name	Principal Investigator	Funder's Name	Funder Ref	Lead Dept
173816		Targeted radiotherapy of prostate cancer with drugs exploiting the aberrant metabolism of tumours	Anthony Chalmers	Chief Scientist Office (CSO)	TCS/16/38	CS - Epigenetics