Epidermal growth factor receptor-related protein inhibits cell growth and induces apoptosis of BxPC3 pancreatic cancer cells.
Dysregulation of the epidermal growth factor receptor (EGFR) signaling network has been frequently reported in pancreatic cancer. Inhibition of EGFR was associated with antitumor effects in both in vitro and in vivo studies of pancreatic cancer. We have previously reported the isolation and characterization of an EGFR-related protein (ERRP), which seems to be a negative regulator of EGFR. In the present investigation, we tested our hypothesis whether recombinant ERRP could be an effective inhibitor of growth of BxPC3 pancreatic cancer cells. Cell growth and apoptosis were measured using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and apoptosis ELISA assay, respectively, in the presence and absence of recombinant ERRP in BxPC3 cells. To evaluate activation of EGFR and its downstream signaling events, levels of phospho-EGFR, phospho-AKT, and phospho-extracellular signal-regulated kinase (phospho-ERK) were determined by Western blot analysis. NF-kappaB activity was measured by electrophoretic mobility shift assay. Our data show, for the first time, that ERRP inhibits the growth of BxPC3 cells in a dose- and time-dependent manner. The EGF or transforming growth factor (TGF)-alpha-induced stimulation of cell growth and activation of EGFR was also inhibited by ERRP. These changes were accompanied by a concomitant attenuation of activation of mitogen-activated protein (MAP) kinases, AKT, and NF-kappaB. ERRP also induced apoptosis as evidenced by increased poly(ADP-ribose) polymerase cleavage and reduction in procaspase3. From these results, we conclude that ERRP is a potent inhibitor of growth of BxPC-3 pancreatic cancer cells, which could be due to attenuation of EGFR cellular signaling processes. We also suggest that ERRP could be a potential therapeutic agent for pancreatic cancer.
Zhang
Yuxiang
Y
Department of Pathology, Karmanos Cancer Institute, Wayne State University School of Medicine, Veterans Affairs Medical Center, Detroit, Michigan 48201, USA.
Banerjee
Sanjeev
S
Wang
Zhi-wei
ZW
Marciniak
Dorota J
DJ
Majumdar
Adhip P N
AP
Sarkar
Fazlul H
FH
D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D048708:Cell Growth Processes / Q000187:drug effects; D045744:Cell Line, Tumor; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D004815:Epidermal Growth Factor / Q000037:antagonists & inhibitors / Q000494:pharmacology; D066246:ErbB Receptors / Q000378:metabolism; D006023:Glycoproteins / Q000494:pharmacology*; D006801:Humans; D016328:NF-kappa B / Q000378:metabolism; D010190:Pancreatic Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D010766:Phosphorylation; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D011994:Recombinant Proteins / Q000494:pharmacology; D016211:Transforming Growth Factor alpha / Q000037:antagonists & inhibitors / Q000494:pharmacology
D006023:Glycoproteins; D016328:NF-kappa B; D011994:Recombinant Proteins; D016211:Transforming Growth Factor alpha; D004815:Epidermal Growth Factor; D011065:Poly(ADP-ribose) Polymerases; C512478:EGFR protein, human; D066246:ErbB Receptors; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases