title: Microelectrode chip based real time monitoring of vital MCF-7 mamma carcinoma cells by impedance spectroscopy.
abstract: Sensorchip based impedance spectroscopy can detect inhibitory effects of human neuropeptide Y (hNPY) on living cells in a non-invasive labelling free way in real time without the need of supporting reagents. Since the discovery that neoplasmatic transformations in breast cancer are correlated with a change of the receptor subtype expression of hNPY in the affected tissue, the hNPY receptor-ligand system has come to the fore of cancer research. Today there are different methods detecting hNPY receptor interactions like fluorescent and radioactive labelling or detecting hNPY-pathway activation like cyclic adenosine monophosphate (cAMP) and G protein-coupled receptor (GPCR)-assays. For all these assays it is necessary to either label related proteins with additional substances, which can affect the nature state of the cell, or the need of producing cell lysate which allows only a snapshot of the investigated cells. To overcome these problems we established a new method to detect hNPY-receptor interactions. Therefore, we monitor the complex electric resistance (impedance) of cells attached to a microelectrode over a wide frequency range. Cell alterations are detected as changes in the impedance spectra. After application of the adenylyl cyclase-stimulating reagent forskolin, impedance is decreased at 5 kHz frequency within minutes. This effect can be inhibited by preincubating the cells with hNPY for a time range of 20 min. The inhibitory effect of hNPY can be washed out and the same cells can be stimulated by forskolin again.
authors.affiliation: University of Leipzig, Centre for Biotechnology and Biomedicine, Faculty of Biosciences, Pharmacy, and Psychology, Institute of Biochemistry, Division of Molecular Biological-Biochemical Processing Technology, Deutscher Platz 5, 04103 Leipzig, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Wolf
authors.forename: Andrée
authors.initials: A
authors.lastname: Rothermel
authors.forename: Annette G
authors.initials: AG
authors.lastname: Beck-Sickinger
authors.forename: Andrea A
authors.initials: AA
authors.lastname: Robitzki
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis*; D001943:Breast Neoplasms / Q000378:metabolism*; D045744:Cell Line, Tumor; D003199:Computer Systems; D017097:Electric Impedance; D004563:Electrochemistry / Q000295:instrumentation*; D004581:Electronics / Q000295:instrumentation; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D008839:Microelectrodes; D009363:Neoplasm Proteins / Q000032:analysis*; D040081:Protein Array Analysis / Q000295:instrumentation*; D017476:Receptors, Neuropeptide Y / Q000032:analysis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D014408:Biomarkers, Tumor; D009363:Neoplasm Proteins; D017476:Receptors, Neuropeptide Y