In situ quantification of HER2-protein tyrosine kinase 6 (PTK6) protein-protein complexes in paraffin sections from breast cancer tissues.
BACKGROUND
Protein tyrosine kinase 6 (PTK6; breast tumour kinase) is overexpressed in up to 86% of the invasive breast cancers, and its association with the oncoprotein human epidermal growth factor receptor 2 (HER2) was shown in vitro by co-precipitation. Furthermore, expression of PTK6 in tumours is linked with the expression of HER2.


RESULTS
In this study, we used the proximity ligation assay (PLA) technique on formalin-fixed paraffin sections from eighty invasive breast carcinoma tissue specimens to locate PTK6-HER2 protein-protein complexes. Proximity ligation assay signals from protein complexes were assessed quantitatively, and expression levels showed a statistically significant association with tumour size (P=0.015) and course of the cancer disease (P=0.012).


CONCLUSIONS
Protein tyrosine kinase 6 forms protein complexes with HER2 in primary breast cancer tissues, which can be visualised by use of the PLA technique. Human epidermal growth factor receptor 2-PTK6 complexes are of prognostic relevance.
Aubele
M
M
Institute of Pathology, Helmholtz Zentrum München, German Research Center for Environmental Health, D-85764 Neuherberg, Germany. aubele@helmholtz-muenchen.de
Spears
M
M
Ludyga
N
N
Braselmann
H
H
Feuchtinger
A
A
Taylor
K J
KJ
Lindner
K
K
Auer
G
G
Stering
K
K
Höfler
H
H
Schmitt
M
M
Bartlett
J M S
JM
D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006801:Humans; D009363:Neoplasm Proteins / Q000378:metabolism*; D016612:Paraffin Embedding; D011485:Protein Binding; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*
D009363:Neoplasm Proteins; D011505:Protein-Tyrosine Kinases; D018719:Erb-b2 Receptor Tyrosine Kinases; C088375:PTK6 protein, human