Identification of ADAM10 as a major source of HER2 ectodomain sheddase activity in HER2 overexpressing breast cancer cells.
Overexpression and activating mutations of ErbB family members have been implicated in the development and progression of a variety of tumor types. Cleavage of the HER2 receptor by an as yet unidentified ectodomain sheddase has been shown to liberate the HER2 extracellular domain (ECD) leaving a fragment with constitutive kinase activity that can provide ligand-independent growth and survival signals to the cell. This process is clinically relevant since HER2 ECD serum levels in metastatic breast cancer patients are associated with a poorer prognosis. Thus, inhibition of the HER2 sheddase may provide a novel therapeutic approach for breast cancer. We describe the use of transcriptional profiling, pharmacological and in vitro approaches to identify the major source of HER2 sheddase activity. Real-time PCR was used to identify those ADAM family members which were expressed in HER2 shedding cell lines. siRNAs that selectively inhibited ADAM10 expression reduced HER2 shedding. In addition, we profiled over 1000 small molecules for in vitro inhibition of a panel of ADAM and MMP proteins; a positive correlation was observed only between ADAM10 inhibition and reduction of HER2 ECD shedding in a cell based assay. Finally, in vitro studies demonstrate that in combination with low doses of Herceptin, selective ADAM10 inhibitors decrease proliferation in HER2 overexpressing cell lines while inhibitors, that do not inhibit ADAM10, have no impact. These results are consistent with ADAM10 being a major determinant of HER2 shedding, the inhibition of which, may provide a novel therapeutic approach for treating a variety of cancers with active HER2 signaling.
Liu
Phillip C C
PC
Drug Discovery, Incyte Corporation, Experimental Station, Wilmington, Delaware 19880, USA.
Liu
Xiangdong
X
Li
Yanlong
Y
Covington
Maryanne
M
Wynn
Richard
R
Huber
Reid
R
Hillman
Milton
M
Yang
Gengjie
G
Ellis
Dawn
D
Marando
Cindy
C
Katiyar
Kamna
K
Bradley
Jodi
J
Abremski
Kenneth
K
Stow
Mark
M
Rupar
Mark
M
Zhuo
Jincong
J
Li
Yun-Long
YL
Lin
Qiyan
Q
Burns
David
D
Xu
Meizhong
M
Zhang
Colin
C
Qian
Ding-Quan
DQ
He
Chunhong
C
Sharief
Vaqar
V
Weng
Lingkai
L
Agrios
Costas
C
Shi
Eric
E
Metcalf
Brian
B
Newton
Robert
R
Friedman
Steven
S
Yao
Wenqing
W
Scherle
Peggy
P
Hollis
Gregory
G
Burn
Timothy C
TC
D051722:ADAM Proteins / Q000378:metabolism*; D000072197:ADAM10 Protein; D053829:Amyloid Precursor Protein Secretases / Q000378:metabolism*; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents / Q000494:pharmacology; D001483:Base Sequence; D001943:Breast Neoplasms / Q000201:enzymology / Q000235:genetics* / Q000473:pathology; D045744:Cell Line, Tumor; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008565:Membrane Proteins / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D034741:RNA, Small Interfering / Q000235:genetics; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D000068878:Trastuzumab
D051722:ADAM Proteins; D000072197:ADAM10 Protein; D053829:Amyloid Precursor Protein Secretases; D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; D008565:Membrane Proteins; D034741:RNA, Small Interfering; D018719:Erb-b2 Receptor Tyrosine Kinases; D000068878:Trastuzumab; C491236:ADAM10 protein, human