title: Monoterpenes enhanced the sensitivity of head and neck cancer cells to radiation treatment in vitro.
abstract: BACKGROUND
  Perillyl alcohol (POH) elicited anticarcinogenic effects in a number of cancer models and pharmacokinetic studies in humans revealed that PA is the major circulating metabolite following POH administration.
  
  
  METHODS
  Effects of PA or POH alone, or in combination with radiation, on human head and neck squamous cell carcinoma cell lines (HNSCC), were investigated using cytotoxicity and flow cytometry assays. HNSCC cells were pretreated with 1.0 mM PA or 0.5 mM POH for 72 h before exposure to 1 or 2Gy dose of radiation.
  
  
  RESULTS
  Pretreatment of the cells with 1.0 mM PA or 0.5 mM POH prior to irradiation, caused the following growth inhibition: HTB-43 (50% or 71%), SCC-25 (55% or 68%), and BroTo (18% or 53%). PA and POH induced cell-cycle arrest and apoptosis.
  
  
  CONCLUSIONS
  PA and POH have potential for use as radiosensitizers in chemo-radiation therapy of head and neck cancers and should be further studied.
authors.affiliation: UNL V Cancer Research Center/Chemistry Department University of Nevada Las Vegas, 4505, Maryland Parkway, Las Vegas, NV 89154-4003, USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Samaila
authors.forename: Beau J
authors.initials: BJ
authors.lastname: Toy
authors.forename: Robert C
authors.initials: RC
authors.lastname: Wang
authors.forename: J Abiodun
authors.initials: JA
authors.lastname: Elegbede
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000378:metabolism / Q000473:pathology / Q000532:radiotherapy*; D002453:Cell Cycle / Q000187:drug effects / Q000528:radiation effects; D045744:Cell Line, Tumor; D053138:Cyclohexenes; D004305:Dose-Response Relationship, Drug; D005434:Flow Cytometry; D006258:Head and Neck Neoplasms / Q000378:metabolism / Q000473:pathology / Q000532:radiotherapy*; D006801:Humans; D039821:Monoterpenes / Q000493:pharmacokinetics / Q000494:pharmacology*; D011838:Radiation-Sensitizing Agents / Q000493:pharmacokinetics / Q000494:pharmacology*; D014410:Tumor Stem Cell Assay
chemical_list: D053138:Cyclohexenes; D039821:Monoterpenes; D011838:Radiation-Sensitizing Agents; C032208:perillyl alcohol; C078706:perillic acid