title: Pigment epithelium-derived factor (PEDF) in neuroblastoma: a multifunctional mediator of Schwann cell antitumor activity.
abstract: Neuroblastoma is notable for its cellular heterogeneity and unpredictable outcome. Tumors are a variable mixture of primitive malignant neuroblasts, more differentiated ganglionic cells, Schwann and endothelial cells. Although often fatal, neuroblastomas can spontaneously regress, possibly due to favorable autocrine and paracrine interactions among these cells. Here, pigment epithelium-derived factor (PEDF), a potent inhibitor of angiogenesis and inducer of neural differentiation, is shown to be produced by ganglionic cells and Schwann cells, but not by more primitive tumor cells. Although undifferentiated neuroblastoma tumor cell secretions were angiogenic primarily due to vascular endothelial growth factor, secretions of Schwann cells were anti-angiogenic due to PEDF. In addition, PEDF was the major factor responsible for Schwann cell's ability to induce tumor cell differentiation in vitro and recombinant PEDF had the same effect in vitro and in vivo. Both the growth and the survival of Schwann cells were enhanced by PEDF. Thus PEDF may serve as a multifunctional antitumor agent in neuroblastomas, inhibiting angiogenesis while promoting the numbers of Schwann cells and differentiated tumor cells that in turn produce PEDF, suggesting that its clinical administration could stimulate a multifaceted antitumor feedback loop with the potential to limit and possibly regress tumor growth.
authors.affiliation: Department of Pathology, Northwestern University Medical School, Chicago, IL 60611, USA. scrawford@northwestern.edu
authors.forename: S E
authors.initials: SE
authors.lastname: Crawford
authors.forename: V
authors.initials: V
authors.lastname: Stellmach
authors.forename: M
authors.initials: M
authors.lastname: Ranalli
authors.forename: X
authors.initials: X
authors.lastname: Huang
authors.forename: L
authors.initials: L
authors.lastname: Huang
authors.forename: O
authors.initials: O
authors.lastname: Volpert
authors.forename: G H
authors.initials: GH
authors.lastname: De Vries
authors.forename: L P
authors.initials: LP
authors.lastname: Abramson
authors.forename: N
authors.initials: N
authors.lastname: Bouck
mesh_terms: D020533:Angiogenesis Inhibitors / Q000378:metabolism; D000818:Animals; D000970:Antineoplastic Agents / Q000378:metabolism* / Q000494:pharmacology; D002417:Cattle; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000502:physiology; D002470:Cell Survival / Q000502:physiology; D002478:Cells, Cultured; D017077:Culture Media, Conditioned / Q000378:metabolism; D016228:Endothelial Growth Factors / Q000378:metabolism; D005136:Eye Proteins; D005260:Female; D006133:Growth Substances / Q000378:metabolism; D006801:Humans; D007279:Injections, Subcutaneous; D008222:Lymphokines / Q000378:metabolism; D051379:Mice; D008819:Mice, Nude; D009414:Nerve Growth Factors; D009447:Neuroblastoma / Q000098:blood supply / Q000378:metabolism* / Q000473:pathology / Q000517:prevention & control*; D010857:Pigment Epithelium of Eye / Q000502:physiology*; D011506:Proteins / Q000008:administration & dosage / Q000378:metabolism / Q000502:physiology*; D051381:Rats; D011916:Rats, Inbred F344; D011994:Recombinant Proteins / Q000008:administration & dosage; D012583:Schwann Cells / Q000378:metabolism / Q000502:physiology*; D015843:Serpins / Q000008:administration & dosage / Q000378:metabolism / Q000502:physiology*; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D000099174:Pigment Epithelium-Derived Factor
chemical_list: D020533:Angiogenesis Inhibitors; D000970:Antineoplastic Agents; D017077:Culture Media, Conditioned; D016228:Endothelial Growth Factors; D005136:Eye Proteins; D006133:Growth Substances; D008222:Lymphokines; D009414:Nerve Growth Factors; D011506:Proteins; D011994:Recombinant Proteins; D015843:Serpins; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D000099174:Pigment Epithelium-Derived Factor