Paracrine Signaling by Platelet-Derived Growth Factor-CC Promotes Tumor Growth by Recruitment of Cancer-Associated Fibroblasts

Abstract

Cancer results from the concerted performance of malignant cells and stromal cells. Cell types populating the microenvironment are enlisted by the tumor to secrete a host of growth-promoting cues, thus upholding tumor initiation and progression. Platelet-derived growth factors (PDGF) support the formation of a prominent tumor stromal compartment by as of yet unidentified molecular effectors. Whereas PDGF-CC induces fibroblast reactivity and fibrosis in a range of tissues, little is known about the function of PDGF-CC in shaping the tumor-stroma interplay. Herein, we present evidence for a paracrine signaling network involving PDGF-CC and PDGF receptor-A in malignant melanoma. Expression of PDGFC in a mouse model accelerated tumor growth through recruitment and activation of different subsets of cancer-associated fibroblasts. In seeking the molecular identity of the supporting factors provided by cancer-associated fibroblasts, we made use of antibody arrays and an in vivo coinjection model to identify osteopontin as the effector of the augmented tumor growth induced by PDGF-CC. In conclusion, we establish paracrine signaling by PDGF-CC as a potential drug target to reduce stromal support in malignant melanoma. [Cancer Res 2009;69(1):369-78]

Rationale for the development of IMC‐3G3, a fully human immunoglobulin G subclass 1 monoclonal antibody targeting the platelet‐derived growth factor receptor α

“…2). [44][45][46][47][48][49][50][51][52][53][54][55][56][57][58][59][60] Several types of cancers, particularly those derived from the ovary, prostate, breast, lung, brain, skin, and bone, express PDGFRa on the malignant cells themselves (Table 1). 22 In 1 experiment in which a human tumor array was probed with a cross-reactive polyclonal rabbit antibody to PDGFRa, PDGFRa expression was noted in approximately 95% of osteosarcomas and chondrosarcomas, in 77% of prostate cancers, in 52% of ovarian cancers, in 65% of breast cancers, and in 51% of lung cancers (N. Loizos, ImClone Systems, unpublished results).…”

“…59 Investigations in multiple cancer types have highlighted the relevance of both PDGF-activated tumor and supporting stromal cells in facilitating cancer growth and metastasis. [44][45][46][47][48][49][50][51]55,57,60 In some cases, specific autocrine or paracrine mechanisms that contribute to malignant progression have been suggested. In 1 experiment, NIH 3T3 cells were transformed when PDGF-A or PDGF-B gene expression was induced using a transfected promoter.…”

“…PDGFs can influence cancer growth and malignant angiogenesis through several mechanisms, including the activation of PDGFRa expressed on cancer cells, stromal fibroblasts, and vascular endothelial cells and by PDGF-induced production of vascular endothelial growth factor (VEGF) by stromal cells. [45][46][47][48][49][50][51][52][53][54][55]57,60 The asterisk indicates that Table 1 required for the development of malignant stroma, 46 a separate study indicated that the induction of PDGF-CC expression in melanoma cells led to accelerated tumor growth through the activation of PDGFRa. 47 In the latter study, the exclusive expression of PDGFRa on cancerassociated stromal fibroblasts illuminated a paracrine mechanism of stromal-regulated melanoma tumor growth.…”

“…[45][46][47][48][49][50][51][52][53][54][55]57,60 The asterisk indicates that Table 1 required for the development of malignant stroma, 46 a separate study indicated that the induction of PDGF-CC expression in melanoma cells led to accelerated tumor growth through the activation of PDGFRa. 47 In the latter study, the exclusive expression of PDGFRa on cancerassociated stromal fibroblasts illuminated a paracrine mechanism of stromal-regulated melanoma tumor growth. It also has been demonstrated that PDGF/ PDGFRa-associated autocrine or paracrine mechanisms that involve tumor and stroma similarly play important roles in the growth of hepatocellular cancers 48,49 and lung cancers, 51 in facilitating bone metastasis in prostate cancers, 60 and in the metastatic spread of lung and breast cancers.…”

Tumorőssejtek szerepe a melanoma progressziójában és heterogenitásában

“…A tumoros sejtek szekretált hírvivő molekulái, mint például a vérlemezke-eredetű növekedési faktor (PDGF) és a stromaeredetű faktor-1 (SDF1) a fibroblastokat a tumor köré toborozzák [24]. Ugyanezek a hírvivők megváltoztatják a fibroblastok génexpresszióját, amely által azok a tumor körül fibrotikusabb extracelluláris mátrixot hoznak létre.…”