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Updated: Jun 21, 2026
A 3D Organotypic Melanoma Spheroid Skin Model
Published on: May 18, 2018
Platelet-derived growth factor-receptor alpha strongly inhibits melanoma growth in vitro and in vivo
Debora Faraone1, Maria Simona Aguzzi, Gabriele Toietta
1Laboratorio Biologia Vascolare e Terapia Genica, Centro Cardiologico Monzino, IRCCS, Milano, Italy.
Abstract:
Cutaneous melanoma is the most aggressive skin cancer; it is highly metastatic and responds poorly to current therapies. The expression of platelet-derived growth factor receptors (PDGF-Rs) is reported to be reduced in metastatic melanoma compared with benign nevi or normal skin; we then hypothesized that PDGF-Ralpha may control growth of melanoma cells. We show here that melanoma cells overexpressing PDGF-Ralpha respond to serum with a significantly lower proliferation compared with that of controls. Apoptosis, cell cycle arrest, pRb dephosphorylation, and DNA synthesis inhibition were also observed in cells overexpressing PDGF-Ralpha. Proliferation was rescued by PDGF-Ralpha inhibitors, allowing to exclude nonspecific toxic effects and indicating that PDGF-Ralpha mediates autocrine antiproliferation signals in melanoma cells. Accordingly, PDGF-Ralpha was found to mediate staurosporine cytotoxicity. A protein array-based analysis of the mitogen-activated protein kinase pathway revealed that melanoma cells overexpressing PDGF-Ralpha show a strong reduction of c-Jun phosphorylated in serine 63 and of protein phosphatase 2A/Balpha and a marked increase of p38gamma, mitogen-activated protein kinase kinase 3, and signal regulatory protein alpha1 protein expression. In a mouse model of primary melanoma growth, infection with the Ad-vector overexpressing PDGF-Ralpha reached a significant 70% inhibition of primary melanoma growth (P < .001) and a similar inhibition of tumor angiogenesis. All together, these data demonstrate that PDGF-Ralpha strongly impairs melanoma growth likely through autocrine mechanisms and indicate a novel endogenous mechanism involved in melanoma control.
Insights
Platelet-derived growth factor receptor alpha (PDGF-Ralpha) significantly inhibits melanoma cell growth and proliferation. Overexpression of PDGF-Ralpha also reduces tumor growth and angiogenesis in mouse models, suggesting a novel melanoma control mechanism.
Area of Science:
- Oncology
- Molecular Biology
- Dermatology
Background:
- Cutaneous melanoma is an aggressive skin cancer with poor therapeutic response and high metastatic potential.
- Reduced expression of platelet-derived growth factor receptors (PDGF-Rs) is observed in metastatic melanoma.
- Hypothesis: PDGF-Ralpha plays a role in controlling melanoma cell growth.
Purpose of the Study:
- To investigate the role of PDGF-Ralpha in melanoma cell proliferation and growth.
- To explore the underlying molecular mechanisms and therapeutic potential of PDGF-Ralpha in melanoma.
Main Methods:
- Melanoma cells were engineered to overexpress PDGF-Ralpha.
- Assays included proliferation, apoptosis, cell cycle analysis, and DNA synthesis.
- Protein array analysis of the mitogen-activated protein kinase (MAPK) pathway was performed.
- A mouse model was used to assess primary melanoma growth and angiogenesis.
Main Results:
- Overexpression of PDGF-Ralpha significantly reduced melanoma cell proliferation, induced apoptosis, cell cycle arrest, and inhibited DNA synthesis.
- PDGF-Ralpha inhibition rescued proliferation, confirming its role in mediating autocrine anti-proliferation signals.
- PDGF-Ralpha overexpression altered MAPK pathway components, including reduced c-Jun phosphorylation and increased p38gamma expression.
- In vivo, PDGF-Ralpha overexpression significantly inhibited primary melanoma growth (70%) and tumor angiogenesis.
Conclusions:
- PDGF-Ralpha acts as a potent endogenous inhibitor of melanoma growth, likely via autocrine mechanisms.
- PDGF-Ralpha signaling represents a novel therapeutic target for melanoma treatment.
- The findings elucidate a new mechanism for melanoma control.
