Down-regulation of platelet-derived growth factor-D inhibits cell growth and angiogenesis through inactivation of Notch-1 and nuclear factor-kappaB signaling.
Platelet-derived growth factor-D (PDGF-D) signaling plays critical roles in the pathogenesis and progression of human malignancies; however, the precise mechanism by which PDGF-D causes tumor cell invasion and angiogenesis remain unclear. Because Notch-1, nuclear factor-kappaB (NF-kappaB), vascular endothelial growth factor (VEGF), and matrix metalloproteinases (MMP) are critically involved in the processes of tumor cell invasion and metastasis, we investigated whether PDGF-D down-regulation could be mechanistically associated with the down-regulation of Notch-1, NF-kappaB, VEGF, and MMP-9, resulting in the inhibition of tumor cell invasion and angiogenesis. Our data showed that down-regulation of PDGF-D leads to the inactivation of Notch-1 and NF-kappaB DNA-binding activity and, in turn, down regulates the expression of its target genes, such as VEGF and MMP-9. We also found that the down-regulation of PDGF-D by small interfering RNA (siRNA) decreased tumor cell invasion, whereas PDGF-D overexpression by cDNA transfection led to increased cell invasion. Consistent with these results, we also found that the down-regulation of PDGF-D not only decreased MMP-9 mRNA and its protein expression but also inhibited the processing of pro-MMP-9 protein to its active form. Moreover, conditioned medium from PDGF-D siRNA-transfected cells showed reduced levels of VEGF and, in turn, inhibited the tube formation of human umbilical vascular endothelial cells, suggesting that down-regulation of PDGF-D leads to the inhibition of angiogenesis. Taken together, we conclude that the down-regulation of PDGF-D by novel approaches could lead to the down-regulation of Notch-1 and, in turn, inactivate NF-kappaB and its target genes (i.e., MMP-9 and VEGF), resulting in the inhibition of invasion and angiogenesis.
Department of Pathology, Karmanos Cancer Institute, Wayne State University, 9374 Scott Hall, 540 East Canfield, Detroit, MI 48201, USA.
Zhiwei
Z
Wang
Dejuan
D
Kong
Sanjeev
S
Banerjee
Yiwei
Y
Li
N Volkan
NV
Adsay
James
J
Abbruzzese
Fazlul H
FH
Sarkar
D000230:Adenocarcinoma / Q000098:blood supply / Q000378:metabolism / Q000517:prevention & control; D017209:Apoptosis / Q000502:physiology; D015153:Blotting, Western; D002465:Cell Movement; D049109:Cell Proliferation; D015536:Down-Regulation; D024202:Electrophoretic Mobility Shift Assay; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D006801:Humans; D007124:Immunoenzyme Techniques; D008222:Lymphokines / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000235:genetics / Q000378:metabolism; D061965:Matrix Metalloproteinase Inhibitors; D016328:NF-kappa B / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D009361:Neoplasm Invasiveness / Q000473:pathology; D009389:Neovascularization, Pathologic / Q000473:pathology; D010190:Pancreatic Neoplasms / Q000098:blood supply* / Q000378:metabolism* / Q000517:prevention & control; D050500:Pancreatitis, Chronic / Q000235:genetics / Q000517:prevention & control; D010982:Platelet-Derived Growth Factor / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000494:pharmacology; D051881:Receptor, Notch1 / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D014158:Transcription, Genetic; D014162:Transfection; D014471:Umbilical Veins / Q000166:cytology / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism
D008222:Lymphokines; D061965:Matrix Metalloproteinase Inhibitors; D016328:NF-kappa B; C497761:NOTCH1 protein, human; C427493:PDGFD protein, human; D010982:Platelet-Derived Growth Factor; D034741:RNA, Small Interfering; D051881:Receptor, Notch1; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D020780:Matrix Metalloproteinase 9