IGFBP-3 gene expression and estrogen receptor status in human breast carcinoma.
Insulin-like growth factors (IGF) I and II are potent mitogens for breast carcinoma proliferation. IGF-mediated proliferative activity can be markedly enhanced by the presence of specific IGF-binding proteins (IGFBPs). IGFBP-3 has been shown to enhance IGF-mediated growth in a number of systems. Studies have demonstrated IGFBP-3 secretion only in estrogen receptor (ER)-negative breast carcinoma cell lines while IGFBP-3 could not be detected in media conditioned by ER-positive cell lines. We investigated whether a relationship exists between ER status and IGFBP-3 mRNA expression in human breast carcinoma biopsy specimens. We have detected IGFBP-3 mRNA in breast carcinoma tissue obtained from patients utilizing in situ hybridization. Quantitation of IGFBP-3 mRNA levels was performed utilizing image cytometry. There was a significantly higher expression of IGFBP-3 mRNA in ER-negative breast carcinoma specimens when compared to the ER-positive specimens. Whether this higher expression of IGFBP-3 mRNA and presumed secretion of IGFBP-3 by ER-negative tumors play a role in the rapid proliferation and poor prognosis of these tumors remains to be determined.
Shao
Z M
ZM
Department of Medicine, University of Maryland, Baltimore 21201.
Sheikh
M S
MS
Ordonez
J V
JV
Feng
P
P
Kute
T
T
Chen
J C
JC
Aisner
S
S
Schnaper
L
L
LeRoith
D
D
Roberts
C T
CT
D001943:Breast Neoplasms / Q000235:genetics*; D002277:Carcinoma / Q000235:genetics*; D002352:Carrier Proteins / Q000378:metabolism*; D015870:Gene Expression; D006801:Humans; D018969:Insulin-Like Growth Factor Binding Proteins; D009693:Nucleic Acid Hybridization; D012333:RNA, Messenger / Q000235:genetics; D011960:Receptors, Estrogen / Q000378:metabolism*; D011980:Receptors, Progesterone / Q000378:metabolism; D016196:S Phase; D013002:Somatomedins / Q000378:metabolism
D002352:Carrier Proteins; D018969:Insulin-Like Growth Factor Binding Proteins; D012333:RNA, Messenger; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D013002:Somatomedins