Platelet-derived growth factor-D promotes ovarian cancer invasion by regulating matrix metalloproteinases 2 and 9

Objective: Platelet-derived growth factor-D (PDGF-D) can enhance invasion and metastasis in several human malignancies, though little is known about its functions in ovarian cancer. Methods: In this study, we detected expression of PDGF-D in ovarian cancer tissues and cell lines by qRT-PCR, immunohistochemistry and western blotting, investigating the influences on cellular proliferation, invasion and apoptosis by upregulating its expression. Results: 79.5% (62/78) of ovarian cancer samples proved to be PDGF-D positive, in contrast to just 38.5%(30/78) in their adjacent non-cancer tissues (p<0.001). Moreover, we found high levels of PDGF-D were correlated with lymph node metastasis (p=0.025) and positive cancer cells in abdominal washings/ascites (p=0.042). In vitro, upregulation of PDGF-D enhanced the invasiveness of SKOV3 cells (p<0.01), but had no impact on cellular proliferation or apoptosis. Furthermore, expression of matrix metalloproteinases 2/9 (MMP2 and MMP9) was positively related with PDGF-D, indicating their involvement in the invasion and metastasis of ovarian cancer. Conclusions: Our findings proved that PDGF-D could promote ovarian cancer invasion by upregulating MMPs, which might be a potential target for ovarian cancer treatment.