title: An exonuclease III protection-based electrochemical method for estrogen receptor assay.
abstract: Estrogen receptor (ER), expressed in approximately 80% of primary breast cancer cells, has proven to be a valuable predictive factor of the disease. Herein, by making use of the specific binding of ER to its DNA response elements, we propose an Exonuclease III (Exo III) protection-based electrochemical method for detecting ER proteins. In this assay, the presence of ER can protect the duplex DNA molecules immobilized on an electrode surface from Exo III-catalyzed digestion, resulting in an increased electrochemical signal. Experimental results have revealed that the proposed method can allow the quantification of ER in the range of 0.5 to 100 nM with a satisfactory detection limit of 0.38 nM. Furthermore, since this approach can also be employed to detect ER directly in nuclear extracts, it may be of great use in biomedical applications in the future.
authors.affiliation: Department of Oncology, the First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China. ym.yin@hotmail.com.
authors.forename: Sha
authors.initials: S
authors.lastname: Zhu
authors.forename: Ya
authors.initials: Y
authors.lastname: Cao
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Xu
authors.forename: Yongmei
authors.initials: Y
authors.lastname: Yin
authors.forename: Genxi
authors.initials: G
authors.lastname: Li
mesh_terms: D015374:Biosensing Techniques; D001943:Breast Neoplasms / Q000175:diagnosis / Q000235:genetics / Q000378:metabolism; D004247:DNA / Q000235:genetics / Q000378:metabolism*; D055664:Electrochemical Techniques / Q000379:methods*; D005090:Exodeoxyribonucleases / Q000378:metabolism*; D005260:Female; D006801:Humans; D011379:Prognosis; D011485:Protein Binding; D011960:Receptors, Estrogen / Q000378:metabolism*; D015203:Reproducibility of Results; D020218:Response Elements / Q000235:genetics; D012680:Sensitivity and Specificity
chemical_list: D011960:Receptors, Estrogen; D004247:DNA; D005090:Exodeoxyribonucleases; C020133:exodeoxyribonuclease III