Inhibition of urokinase activity reduces primary tumor growth and metastasis formation in a murine lung carcinoma model.
BACKGROUND
Lung cancer is the most common malignancy in humans. Urokinase (uPA) plays a crucial role in carcinogenesis by facilitating tumor cell invasion and metastasis.


OBJECTIVE
We investigated the effect of the highly specific urokinase inhibitor CJ-463 (benzylsulfonyl-D-Ser-Ser-4-amidinobenzylamide) on tumor growth, metastasis formation, and tumor vascularization in the murine Lewis lung carcinoma (LLC) and a human small lung cancer model.


METHODS
A quantity of 3 x 10(6) LLC cells were subcutaneously injected into the right flank of C57Bl6/N mice, uPA knock out, and uPA receptor knockout mice. Seven days later mice were randomized to receive intraperitoneally either saline (control group), CJ-463 (10 and 100 mg/kg, twice a day), or its ineffective stereoisomer (10 mg/kg, twice a day). Tumor volume was measured every second day and metastasis formation was monitored by volumetric-computed tomography. Twelve days after onset of treatment mice were killed and tumors were prepared for histologic examination.


RESULTS
Treatment with CJ-463 resulted in a significant inhibition of primary tumor growth, with the highest efficacy seen in the 100 mg/kg group. In addition, histological analysis of the lung revealed a significant reduction in lung micrometastasis in the 100 mg/kg group. Similarly, a reduced seeding of tumor cells into the lung after intravenous injection of LLC cells was observed in inhibitor-treated mice. In these mice, treatment with CJ-463 appeared not to significantly alter the relative extent of tumor vascularization. In vitro, proliferation of LLC cells remained unchanged upon inhibitor treatment. CJ-463 was found to similarly reduce tumor growth in uPA receptor knockout mice, but was ineffective in uPA knockout mice.


CONCLUSIONS
Our results suggest that synthetic low-molecular-weight uPA-inhibitors offer as novel agents for treatment of lung cancer.
Henneke
Ingrid
I
Universty of Giessen Lung Center, Dept. of Internal Medicine, Germany.
Greschus
Susanne
S
Savai
Rajkumar
R
Korfei
Martina
M
Markart
Philipp
P
Mahavadi
Poornima
P
Schermuly
Ralph T
RT
Wygrecka
Malgorzata
M
Stürzebecher
Jörg
J
Seeger
Werner
W
Günther
Andreas
A
Ruppert
Clemens
C
D000818:Animals; D001550:Benzamidines; D015153:Blotting, Western / Q000379:methods; D018827:Carcinoma, Lewis Lung / Q000201:enzymology* / Q000473:pathology / Q000556:secondary; D018929:Cell Culture Techniques / Q000379:methods; D049109:Cell Proliferation / Q000187:drug effects; D054893:Cone-Beam Computed Tomography / Q000379:methods; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging / Q000201:enzymology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D016513:Mice, SCID; D055752:Small Cell Lung Carcinoma / Q000201:enzymology* / Q000473:pathology / Q000556:secondary; D012965:Sodium Chloride / Q000008:administration & dosage; D016896:Treatment Outcome; D047368:Tumor Burden / Q000187:drug effects; D014568:Urokinase-Type Plasminogen Activator / Q000187:drug effects*
D001550:Benzamidines; D004791:Enzyme Inhibitors; D012965:Sodium Chloride; D014568:Urokinase-Type Plasminogen Activator