Platelet-derived growth factor-D contributes to aggressiveness of breast cancer cells by up-regulating Notch and NF-κB signaling pathways.
Platelet-derived growth factor-D (PDGF-D) has been linked with several human malignancies; however, its role in breast cancer progression is not known. We found that PDGF-D expressing breast cancer cell lines MDA-MB-231 and SUM-149 are more invasive compared to cell lines with little or no expression of PDGF-D such as MDA-MB-468 and MCF-7 cells. Over-expression of PDGF-D in PDGF-D low expressing MDA-MB-468 and MCF-7 cells by cDNA transfection showed increased cell proliferation while silencing the expression of PDGF-D by siRNA in PDGF-D high expressing MDA-MB-231 and SUM-149 cells showed decreased cell proliferation and increased apoptosis. Moreover, PDGF-D over-expression was positively correlated with the expression of Notch-1 and Jagged-1, and the expression of mesenchymal markers (Vimentin and ZEB-2) with concomitant decreased expression of epithelial marker E-cadherin. Since NF-κB activation plays a crucial role in Notch signaling as well as in epithelial-mesenchymal transition and tumor aggressiveness, we determined the DNA binding activity of NF-κB and our findings are consistent showing that PDGF-D over-expression led to increased DNA binding activity of NF-κB while it was found to be decreased by inactivation of PDGF-D. These results were also consistent with the expression and activity of MMP-9 and VEGF, as well as invasive characteristics. Further, forced expression of Notch-1/Jagged-1 by cDNA transfection de-repressed the effects of PDGF-D silencing on NF-κB activity and invasion. From these results, we conclude that PDGF-D plays an important role in breast tumor aggressiveness and this process is mechanistically linked with the activation of Notch and NF-κB signaling.
Ahmad
Aamir
A
Department of Pathology, Barbara Ann Karmanos Cancer Center, Wayne State University School of Medicine, Detroit, MI 48201, USA.
Wang
Zhiwei
Z
Kong
Dejuan
D
Ali
Raza
R
Ali
Shadan
S
Banerjee
Sanjeev
S
Sarkar
Fazlul H
FH
D017209:Apoptosis; D015153:Blotting, Western; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D002135:Calcium-Binding Proteins; D002448:Cell Adhesion; D002465:Cell Movement; D049109:Cell Proliferation; D003114:Colony-Forming Units Assay; D024202:Electrophoretic Mobility Shift Assay; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins; D000072100:Jagged-1 Protein; D008156:Luciferases / Q000378:metabolism; D008222:Lymphokines / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D008565:Membrane Proteins; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism*; D009361:Neoplasm Invasiveness; D010982:Platelet-Derived Growth Factor / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics; D051881:Receptor, Notch1 / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000072099:Serrate-Jagged Proteins; D015398:Signal Transduction; D014407:Tumor Cells, Cultured
D002135:Calcium-Binding Proteins; D036341:Intercellular Signaling Peptides and Proteins; C000606273:JAG1 protein, human; D000072100:Jagged-1 Protein; D008222:Lymphokines; D008565:Membrane Proteins; D016328:NF-kappa B; C497761:NOTCH1 protein, human; C427493:PDGFD protein, human; D010982:Platelet-Derived Growth Factor; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D051881:Receptor, Notch1; D000072099:Serrate-Jagged Proteins; D008156:Luciferases