Neutrophil gelatinase-associated lipocalin: a novel suppressor of invasion and angiogenesis in pancreatic cancer.
Neutrophil gelatinase-associated lipocalin (NGAL) is a 25-kDa secreted acute phase protein, which is also up-regulated in multiple cancers, including breast, lung, and pancreas. Recently, NGAL has been proposed as an early biomarker in pancreatic cancer (PaCa). However, its biological role in PaCa is unknown. In this study, we examined in vitro and in vivo the functional role of NGAL in PaCa. Well- to moderately differentiated PaCa cells (AsPC-1, BxPC-3, and Capan-2) expressed high levels of NGAL but moderately to poorly differentiated PaCa cells (PANC-1 and MIAPaCa-2) expressed undetectable NGAL levels. Immunohistochemistry of untreated tissue microarray showed specific NGAL staining in resected PaCa specimens (P = 0.0167). Stable NGAL overexpression (MIAPaCa-2 and PANC-1) significantly blocked PaCa cell adhesion and invasion in vitro and vice versa with stable PaCa clones (BxPC-3 and AsPC-1). Moreover, NGAL overexpression reduced focal adhesion kinase (FAK) tyrosine-397 phosphorylation in PaCa cells. Furthermore, NGAL overexpression potently decreased angiogenesis in vitro partly through reduced vascular endothelial growth factor (VEGF) production and vice versa. Stable NGAL overexpression or underexpression had no effect on PaCa cell survival, viability, and response to chemotherapeutic drugs. Finally, MIAPaCa-2 cells overexpressing NGAL reduced tumor volume (P = 0.012), local and distant metastasis (P = 0.002), and angiogenesis (P = 0.05) with no effect on K-67 proliferation index (P > 0.1) in an orthotopic nude mouse PaCa model. Collectively, our results suggest that NGAL reduces adhesion/invasion partly by suppressing FAK activation and inhibits angiogenesis partly by blocking VEGF production in PaCa cells. Thus, NGAL is a potential suppressor of invasion and angiogenesis in advanced PaCa.
Tong
Zhimin
Z
Department of Gastroenterology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA.
Kunnumakkara
Ajaikumar B
AB
Wang
Huamin
H
Matsuo
Yoichi
Y
Diagaradjane
Parmeswaran
P
Harikumar
Kuzhuvelil B
KB
Ramachandran
Vijaya
V
Sung
Bokyung
B
Chakraborty
Arup
A
Bresalier
Robert S
RS
Logsdon
Craig
C
Aggarwal
Bharat B
BB
Krishnan
Sunil
S
Guha
Sushovan
S
D000209:Acute-Phase Proteins / Q000502:physiology*; D017209:Apoptosis; D015153:Blotting, Western; D002448:Cell Adhesion; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002478:Cells, Cultured; D006801:Humans; D007150:Immunohistochemistry; D000071068:Lipocalin-2; D054834:Lipocalins / Q000502:physiology*; D009361:Neoplasm Invasiveness; D009389:Neovascularization, Pathologic; D010190:Pancreatic Neoplasms / Q000378:metabolism / Q000473:pathology*; D011518:Proto-Oncogene Proteins / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction
D000209:Acute-Phase Proteins; C489506:LCN2 protein, human; D000071068:Lipocalin-2; D054834:Lipocalins; D011518:Proto-Oncogene Proteins