title: Critical evaluation of KCNJ3 gene product detection in human breast cancer: mRNA in situ hybridisation is superior to immunohistochemistry.
abstract: Increased expression levels of KCNJ3 have been correlated with lymph node metastases and poor prognosis in patients with breast cancer, suggesting a prognostic role of KCNJ3 We aimed to establish protocols for the detection of KCNJ3 in formalin-fixed, paraffin-embedded (FFPE) breast cancer tissue. Several antibodies were tested for sensitivity and specificity by western blot, followed by optimisation of the immunohistochemistry (IHC) procedure and establishment of KCNJ3 mRNA in situ hybridisation (ISH). Methods were validated by processing 15 FFPE breast cancer samples for which microarray data were available. Spearman's rank correlation analysis resulted in borderline significant correlation for IHC versus ISH (rS: 0.625; p<0.05) and IHC versus microarray (rS: 0.668; p<0.01), but in significant correlation for ISH versus microarray (rS: 0.861; p<0.001). The ISH method was superior to IHC, regarding robustness, sensitivity and specificity and will aid to further study expression levels of KCNJ3 in both malignant and physiological conditions.
authors.affiliation: Molecular Physiology Group, Institute of Biophysics, Medical University of Graz, Graz, Austria.|Research Unit on Ion Channels and Cancer Biology, Medical University of Graz, Graz, Austria.
authors.forename: Sarah
authors.initials: S
authors.lastname: Kammerer
authors.affiliation: Institute of Pathology, Medical University of Graz, Graz, Austria.
authors.forename: Stephan Wenzel
authors.initials: SW
authors.lastname: Jahn
authors.affiliation: Institute of Pathology, Medical University of Graz, Graz, Austria.
authors.forename: Elke
authors.initials: E
authors.lastname: Winter
authors.affiliation: Institute of Pathology, Medical University of Graz, Graz, Austria.
authors.forename: Sylvia
authors.initials: S
authors.lastname: Eidenhammer
authors.affiliation: Molecular Physiology Group, Institute of Biophysics, Medical University of Graz, Graz, Austria.|Research Unit on Ion Channels and Cancer Biology, Medical University of Graz, Graz, Austria.
authors.forename: Simin
authors.initials: S
authors.lastname: Rezania
authors.affiliation: Institute of Pathology, Medical University of Graz, Graz, Austria.
authors.forename: Peter
authors.initials: P
authors.lastname: Regitnig
authors.affiliation: Division of Oncology, Department of Internal Medicine, Medical University of Graz, Graz, Austria.
authors.forename: Martin
authors.initials: M
authors.lastname: Pichler
authors.affiliation: Molecular Physiology Group, Institute of Biophysics, Medical University of Graz, Graz, Austria.|Research Unit on Ion Channels and Cancer Biology, Medical University of Graz, Graz, Austria.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Schreibmayer
authors.affiliation: Research Unit on Ion Channels and Cancer Biology, Medical University of Graz, Graz, Austria.|Division of Oncology, Department of Internal Medicine, Medical University of Graz, Graz, Austria.
authors.forename: Thomas
authors.initials: T
authors.lastname: Bauernhofer
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000235:genetics* / Q000378:metabolism; D015153:Blotting, Western; D001940:Breast / Q000473:pathology; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000235:genetics / Q000378:metabolism; D002277:Carcinoma / Q000175:diagnosis* / Q000235:genetics / Q000378:metabolism; D005260:Female; D051676:G Protein-Coupled Inwardly-Rectifying Potassium Channels / Q000235:genetics* / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D061986:MCF-7 Cells; D008875:Middle Aged; D016612:Paraffin Embedding; D011379:Prognosis; D012333:RNA, Messenger / Q000032:analysis; D012680:Sensitivity and Specificity
chemical_list: D014408:Biomarkers, Tumor; D051676:G Protein-Coupled Inwardly-Rectifying Potassium Channels; C497066:KCNJ3 protein, human; D012333:RNA, Messenger
keywords: ANTIBODIES; BREAST CANCER; IMMUNOHISTOCHEMISTRY; IN SITU HYBRIDISATION; METHODOLOGY