Early placenta insulin-like growth factor (pro-EPIL) is overexpressed and secreted by c-erbB-2-positive cells with high invasion potential.
By differential-display PCR a subclone of the SKBR3 cell line with high in vitro transendothelial invasiveness was identified to express increased levels of the INSL-4 gene. This new member of the insulin-like growth factor family encodes for a peptide, designated early placenta insulin-like (EPIL), being expressed in the so-called "invasive" phase of the placental development. Immunohistochemistry on tissue microarrays revealed a heterogeneous expression of EPIL in breast cancer tissue and no expression in the surrounding stroma cells. A coexpression of pro-EPIL and c-erbB-2 could be observed predominantly in cell clusters at the infiltrating edge of the tumor. Our results give new suggestions for the presence of a signaling network of receptor tyrosine kinases underlying breast cancer invasion and metastasis.
Brandt
Burkhard
B
Institute for Clinical Chemistry and Laboratory Medicine, Westfälische Wilhelms-Universität Münster, Germany 48149. brandt@uni-muenster.de
Roetger
Antje
A
Bidart
Jean-Michel
JM
Packeisen
Jens
J
Schier
Katrin
K
Mikesch
Jan-Hendrik
JH
Kemming
Dirk
D
Boecker
Werner
W
Yu
Dihua
D
Buerger
Horst
H
D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D015870:Gene Expression; D006133:Growth Substances; D006801:Humans; D007150:Immunohistochemistry; D036341:Intercellular Signaling Peptides and Proteins; D009361:Neoplasm Invasiveness; D011257:Pregnancy Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000096:biosynthesis*; D014407:Tumor Cells, Cultured
D006133:Growth Substances; D036341:Intercellular Signaling Peptides and Proteins; D011257:Pregnancy Proteins; D018719:Erb-b2 Receptor Tyrosine Kinases; C101126:INSL4 protein, human