Heparin affin regulatory peptide/pleiotrophin negatively affects diverse biological activities in C6 glioma cells

Integrin α v β 3 is a pleiotrophin receptor required for pleiotrophin‐induced endothelial cell migration through receptor protein tyrosine phosphatase β/ζ

“…We have recently shown that although both PTN and RPTP␤/ have been considered to promote glioma cell growth in vivo and in vitro (1), in rat glioma C6 cells, endogenous PTN has a negative effect on cell growth and angiogenicity (47). It has been shown that expression of integrin ␣ v ␤ 3 in gliomas correlates with tumor grade and is not restricted to tumor vasculature but is also observed in glioma cells themselves (48).…”

The role of pleiotrophin in bone repair

“…Antisense PTN expression in human prostate LNCaP cells decreases prostate cancer cell-induced angiogenesis in vitro and in vivo [71,72]. On the other hand, antisense PTN expression in rat glioma C6 cells decreases glioma cell-induced angiogenesis in vitro and in vivo [73] and PTN seems to act as an angiostatic factor in an in vivo neuroblastoma model that is resistant to irinotecan [74]. In both cases, its regulatory effect on VEGF actions has been discussed as the most likely mechanism.…”

Roles of pleiotrophin in tumor growth and angiogenesis

“…It has been detected in lysates and conditioned medium from contact-arrested NIH 3T3 fibroblasts, but not in cells transformed by the ras oncogene [107], and its expression is up-regulated in confluent compared with actively proliferating cells [108,109]. Its expression is low or absent in neuroblastomas with a poor prognosis [110], and negatively affects growth and migration of several glioma cells lines [111,112].…”

“…It also decreases the expression of the VEGF receptor KDR, another mechanism through which it potentially inhibits VEGF angiogenic activities in vitro [125]. Finally, decrease in the expression of endogenous PTN in C6 glioma cells significantly increased the angiogenic potential of these cells in vitro, partially due to increased availability and activity of VEGF [111].…”