title: Extreme Expression of DNA Repair Protein Apurinic/Apyrimidinic Endonuclease 1 (APE1) in Human Breast Cancer As Measured by Liquid Chromatography and Isotope Dilution Tandem Mass Spectrometry.
abstract: Apurinic/apyrimidinic endonuclease 1 (APE1) is a DNA repair protein and plays other important roles. Increased levels of APE1 in cancer have been reported. However, available methods for measuring APE1 levels are indirect and not quantitative. We previously developed an approach using liquid chromatography and tandem mass spectrometry with isotope dilution to accurately measure APE1 levels. Here, we applied this methodology to measure APE1 levels in normal and cancerous human breast tissues. Extreme expression of APE1 in malignant tumors was observed, suggesting that breast cancer cells may require APE1 for survival. Accurate measurement of APE1 may be essential for the development of novel treatment strategies and APE1 inhibitors as anticancer drugs.
authors.affiliation: Biomolecular Measurement Division, National Institute of Standards and Technology , Gaithersburg, Maryland 20899, United States.|Department of Toxicology, Faculty of Pharmacy, Gazi University , Ankara, Turkey.
authors.forename: Erdem
authors.initials: E
authors.lastname: Coskun
authors.affiliation: Biomolecular Measurement Division, National Institute of Standards and Technology , Gaithersburg, Maryland 20899, United States.
authors.forename: Pawel
authors.initials: P
authors.lastname: Jaruga
authors.affiliation: Biomolecular Measurement Division, National Institute of Standards and Technology , Gaithersburg, Maryland 20899, United States.
authors.forename: Prasad T
authors.initials: PT
authors.lastname: Reddy
authors.affiliation: Biomolecular Measurement Division, National Institute of Standards and Technology , Gaithersburg, Maryland 20899, United States.
authors.forename: Miral
authors.initials: M
authors.lastname: Dizdaroglu
mesh_terms: D000595:Amino Acid Sequence; D001940:Breast / Q000473:pathology*; D001943:Breast Neoplasms / Q000737:chemistry / Q000473:pathology*; D045744:Cell Line, Tumor; D002853:Chromatography, Liquid; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase / Q000032:analysis*; D005260:Female; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D053719:Tandem Mass Spectrometry
chemical_list: C085108:APEX1 protein, human; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase