Identification of the cancer cell proliferation and survival functions of proHB-EGF by using an anti-HB-EGF antibody.
OBJECTIVE
Heparin-binding epidermal growth factor-like growth factor (HB-EGF) is a member of the epidermal growth factor family. The membrane-bound proHB-EGF is known to be a precursor of the soluble form of HB-EGF (sHB-EGF), which promotes cell proliferation and survival. While the functions of sHB-EGF have been extensively studied, it is not yet fully understood if proHB-EGF is also involved in cellular signaling events. In this study, we utilized the anti-HB-EGF monoclonal antibodies Y-142 and Y-073, which have differential specificities toward proHB-EGF, in order to elucidate proHB-EGF functions in cancer cells.


METHODS
The biological activities of proHB-EGF were assessed in cell proliferation, caspase activation, and juxtacrine activity assays by using a 3D spheroid culture of NUGC-3 cells.


RESULTS
Y-142 and Y-073 exhibited similar binding and neutralizing activities for sHB-EGF. However, only Y-142 bound to proHB-EGF. We could detect the function of endogenously expressed proHB-EGF in a 3D spheroid culture. Blocking proHB-EGF with Y-142 reduced spheroid formation, suppressed cell proliferation, and increased caspase activation in the 3D spheroid culture of NUGC-3 cells.


CONCLUSIONS
Our results show that proHB-EGF acts as a cell proliferation and cell survival factor in cancer cells. The results suggest that proHB-EGF may play an important role in tumor progression.
Takeda San Francisco, Inc., South San Francisco, California, USA. shuji.sato@takeda.com
Shuji
S
Sato
Hiroko
H
Kamada
Takahiro
T
Watanabe
Isamu
I
Tsuji
Jinhong
J
Fan
D000888:Antibodies, Anti-Idiotypic / Q000008:administration & dosage*; D017209:Apoptosis / Q000235:genetics; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002470:Cell Survival / Q000235:genetics*; D002471:Cell Transformation, Neoplastic / Q000235:genetics; D066257:Heparin-binding EGF-like Growth Factor; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics* / Q000276:immunology; D009369:Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D015398:Signal Transduction
D000888:Antibodies, Anti-Idiotypic; C587883:HBEGF protein, human; D066257:Heparin-binding EGF-like Growth Factor; D036341:Intercellular Signaling Peptides and Proteins