EGF receptor antagonism improves survival in a murine model of pancreatic adenocarcinoma.
BACKGROUND
The purpose of this study was to determine whether inhibition of the epidermal growth factor receptor (EGFR) is a plausible therapeutic strategy in pancreatic cancer.


METHODS
A human pancreatic cancer cell line (HPAC) was evaluated for the presence of EGFR with rtPCR and immunohistochemistry. Cells were grown in the presence of either 50 or 100 microM of erlotinib (EGFRI) for 72 hours and evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Eighty-six athymic nude/nude mice underwent orthotopic implantation of 10(7) HPAC cells and were blindly randomized into four groups: (1) Control; (2) Batimastat, a matrix metalloproteinase inhibitor (MMPI) at 400 ng/ml qod; (3) EGFRI at 100 mg/kg qd; and (4) MMPI and EGRRI (both). In vitro and in vivo effects of EGFRI with and without MMPI were compared.


RESULTS
HPAC demonstrated high levels of expression of both the EGFR gene and the gene product. In vitro, both doses of EGFRI significantly reduced proliferation of HPAC at 48 (50 microM: 1.15 + 0.05 [st dev] versus 0.63 + 0.09 abs, P < 0.001) and 72 h (50 microM: 1.48 +/- 0.09 versus 0.73 +/- 0.05 abs, P < 0.001, paired Student's t-test). In vivo, each treatment group demonstrated a significant survival advantage (P = 0.0002 group 2, P = 0.0001 group 3, P = 0.012 group 4, log rank test) over controls. Mice treated with EGFRI showed reduced tumor implantation, size, weight, metastatic potential, and jaundice as compared to controls and MMPI-treated mice (all P < 0.05, Fisher's exact test).


CONCLUSIONS
EGF receptor antagonism is not only a plausible therapy for treatment of ductal adenocarcinoma of the pancreas, but is also superior to matrix metalloproteinase inhibition alone or in combination.
Durkin
Alan J
AJ
University of South Florida College of Medicine, Department of Surgery, Tampa General Hospital, Digestive Disorders Center, Tampa, Florida 33612, USA.
Osborne
Dana A
DA
Yeatman
Timothy J
TJ
Rosemurgy
Alexander S
AS
Armstrong
Cindy
C
Zervos
Emmanuel E
EE