PDGF‐C promotes cell proliferation partially via downregulating BOP1.

Platelet‐derived growth factor C (PDGF‐C) is a member of PDGF/VEGF family, which is well‐known for important functions in the vascular system. It is widely reported that PDGF‐C is able to modulate cell proliferation. However, it is still not very clear about this cell modulating mechanism at the molecular level. In a screening of factors regulated by PDGF‐C protein, we fished out a factor called block of proliferation 1 (BOP1), which is a pivotal regulator of ribosome biogenesis and cell proliferation. In this study, we investigated the regulation of BOP1 by PDGF‐C and its role in modulating cell proliferation. We found that BOP1 was downregulated at both mRNA and protein levels in cells treated with PDGF‐C‐containing conditioned medium. On the other hand, BOP1 was upregulated in PDGF‐C deficient mice. Furthermore, we confirmed that overexpression of BOP1 inhibited HEK293A cell proliferation, whereas knockdown of BOP1 promoted cell proliferation. The mitogenic effect of PDGF‐C could be attenuated by downregulation of BOP1. Our results demonstrate a clear PDGF‐C–BOP1 signaling that modulates cell proliferation. [ABSTRACT FROM AUTHOR]