title: Quantitative electrochemical detection of cathepsin B activity in breast cancer cell lysates using carbon nanofiber nanoelectrode arrays toward identification of cancer formation.
abstract: The proteolytic activity of cathepsin B in complex breast cell lysates has been measured with alternating current voltammetry (ACV) using ferrocene (Fc)-labeled-tetrapeptides immobilized on nanoelectrode arrays (NEAs) fabricated with vertically aligned carbon nanofibers (VACNFs). Four types of breast cells have been tested, including normal breast cells (HMEC), transformed breast cells (MCF-10A), breast cancer cells (T47D), and metastatic breast cancer cells (MDA-MB-231). The detected protease activity was found increased in cancer cells, with the MDA-MB-231 metastatic cancer cell lysate showing the highest cathepsin B activity. The equivalent cathepsin B concentration in MDA-MB-231 cancer cell lysate was quantitatively determined by spiking recombinant cathepsin B into the immunoprecipitated MDA-MB-231 lysate and the HMEC whole cell lysate. The results illustrated the potential of this technique as a portable multiplex electronic device for cancer diagnosis and treatment monitoring through rapid profiling the activity of specific cancer-relevant proteases.
  
  
  BACKGROUND
  Breast cancer is the most common cancer in women. In this report, the authors applied the technique of nanoelectrode arrays to try to detect and compare cathepsin B activities in normal and breast cancer cells. It was found that protease activity correlated positively with the degree of malignancy cancer cells. Taking this further, this technique may be useful for rapid diagnosis of cancer in the future.
authors.affiliation: Department of Chemistry, Kansas State University, Manhattan, KS, USA.
authors.forename: Luxi Z
authors.initials: LZ
authors.lastname: Swisher
authors.affiliation: Department of Chemistry, Kansas State University, Manhattan, KS, USA.
authors.forename: Allan M
authors.initials: AM
authors.lastname: Prior
authors.affiliation: Department of Chemistry, Kansas State University, Manhattan, KS, USA.
authors.forename: Medha J
authors.initials: MJ
authors.lastname: Gunaratna
authors.affiliation: Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS, USA.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Shishido
authors.affiliation: Department of Chemistry, Kansas State University, Manhattan, KS, USA.
authors.forename: Foram
authors.initials: F
authors.lastname: Madiyar
authors.affiliation: Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS, USA.
authors.forename: Thu A
authors.initials: TA
authors.lastname: Nguyen
authors.affiliation: Department of Chemistry, Kansas State University, Manhattan, KS, USA.
authors.forename: Duy H
authors.initials: DH
authors.lastname: Hua
authors.affiliation: Department of Chemistry, Kansas State University, Manhattan, KS, USA. Electronic address: junli@ksu.edu.
authors.forename: Jun
authors.initials: J
authors.lastname: Li
mesh_terms: D001943:Breast Neoplasms / Q000175:diagnosis / Q000235:genetics* / Q000473:pathology; D002244:Carbon / Q000737:chemistry; D002401:Cathepsin B / Q000235:genetics / Q000302:isolation & purification*; D045744:Cell Line, Tumor; D005260:Female; D006801:Humans; D057139:Nanofibers / Q000737:chemistry*; D059748:Proteolysis
chemical_list: D002244:Carbon; D002401:Cathepsin B
keywords: Cancer formation; Electrochemical protease profiling; Nanoelectrode array; Proteolytic activity; Vertically aligned carbon nanofibers