title: Interference by anti-cancer chemotherapeutic agents in the MTT-tumor chemosensitivity assay.
abstract: BACKGROUND
  One of the major goals of oncology is to predict the response of patients with cancer to chemotherapeutic agents by employing laboratory methods variously called 'tumor chemosensitivity assays', 'drug response assays', or 'drug sensitivity assays', in vitro. The MTT assay is one of the methods used to predict the drug response in malignancies. However, it may suffer from interference by the anticancer drugs with the MTT assay.
  
  
  METHODS
  The MTT assay, a colorimetric viability assay, was checked in a cell-free system in terms of its possible chemical interactions with 22 different anticancer drugs.
  
  
  RESULTS
  It was found that epirubicine, paclitaxel, doxetaxel, and cisplatin caused a relatively significant increase in absorbance values, resulting in the MTT assay giving rise to false results (untrue increase in viability) although most of the drugs tested did not seem to cause any significant change.
  
  
  CONCLUSIONS
  It was concluded that before employing the MTT assay, drugs (or any kind of substances) to be included in the assay should be checked first in terms of possible chemical interactions with MTT, otherwise it may be impossible to evaluate the MTT viability assay results correctly.
authors.affiliation: University of Uludag, School of Medicine, Department of Biochemistry, Bursa, Turkey. eulukaya@uludag.edu.tr
authors.forename: Engin
authors.initials: E
authors.lastname: Ulukaya
authors.forename: Mukaddes
authors.initials: M
authors.lastname: Colakogullari
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Wood
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry* / Q000494:pharmacology; D002945:Cisplatin / Q000737:chemistry / Q000494:pharmacology; D003124:Colorimetry / Q000379:methods; D004347:Drug Interactions; D004354:Drug Screening Assays, Antitumor / Q000379:methods*; D005047:Etoposide / Q000737:chemistry / Q000494:pharmacology; D013778:Tetrazolium Salts / Q000737:chemistry*; D013844:Thiazoles / Q000737:chemistry*
chemical_list: D000970:Antineoplastic Agents; D013778:Tetrazolium Salts; D013844:Thiazoles; D005047:Etoposide; C022616:thiazolyl blue; D002945:Cisplatin