Effects of pigment epithelium derived factor (PEDF) on malignant peripheral nerve sheath tumours (MPNSTs)

Malignant peripheral nerve sheath tumor: models, biology, and translation

Malignant peripheral nerve sheath tumors (MPNSTs) are aggressive, invasive cancer that comprise around 10% of all soft tissue sarcomas and develop in about 8-13% of patients with Neurofibromatosis Type 1. They are associated with poor prognosis and are the leading cause of mortality in NF1 patients. MPNSTs can also develop sporadically or following exposure to radiation. There is currently no effective targeted therapy to treat MPNSTs and surgical removal remains the mainstay treatment. Unfortunately, surgery is not always possible due to the size and location of the tumor, thus, a better understanding of MPNST initiation and development is required to design novel therapeutics. Here, we provide an overview of MPNST biology and genetics, discuss findings regarding the developmental origin of MPNST, and summarize the various model systems employed to study MPNST. Finally, we discuss current management strategies for MPNST, as well as recent developments in translating basic research findings into potential therapies.

Pedf derived peptides affect colorectal cancer cell lines resistance and tumour re-growth capacity

Relapse after chemotherapy treatment depends on the cancer initiating cells (CICs). PEDF (Pigmented Epithelium Derived Factor) is an anti-angiogenic, neurotrophic and self-renewal regulator molecule, also involved in CICs biology. Acute and chronic exposition of colon cancer cell lines to CT/CTE PEDF-derived peptides decreased drug-resistance to conventional colorectal cancer treatments, such as oxaliplatin or irinotecan. We confirmed a reduction in the irinotecan and oxaliplatin IC50 doses for all tested tumour cell lines. After xenograft transplantation, CT/CTE treatments also produced a reduction in resistance to conventional chemotherapy treatments as in culture-assays. Metastatic capacity of these treated cell lines was also depleted. The PEDF signaling pathway could be a future therapeutic tool for use as an adjuvant therapy that decreases IC50 dosis, adverse effects and treatment costs. This pathway could also be involved in an increase of the time relapse in patients, decreased tumourigenicity, and decreased capacity to produce metastasis.

Targeting of AKT/ERK/CTNNB1 by DAW22 as a potential therapeutic compound for malignant peripheral nerve sheath tumor

Malignant peripheral nerve sheath tumors (MPNSTs) are an aggressive form of soft tissue neoplasm with extremely poor prognosis and no effective medical options currently available. MPNSTs can occur either sporadically or in association with the neurofibromatosis type 1 (NF1) syndrome. Importantly, activation of RAS/RAF/MEK/ERK, PI3K/AKT/mTOR, and WNT/CTNNB1 signaling pathways has been reported in both NF1-related and late-stage sporadic MPNSTs. In this study, we found that DAW22, a natural sesquiterpene coumarin compound isolated from Ferula ferulaeoides (Steud.) Korov., could inhibit cell proliferation and colony formation in five established human MPNST cancer cell lines. Further molecular mechanism exploration indicated that DAW22 could target the main components in the MPNST tumorigenic pathways: namely suppress phosphorylation of AKT and ERK, and reduce levels of non-phospho (active) CTNNB1. Using the xenograft mouse model transplanted with human MPNST cancer cell line, daily treatment with DAW22 for 25 days was effective in reducing tumor growth. These results support DAW22 as an alternative therapeutic compound for MPNST treatment by affecting multiple signaling transduction pathways in its disease progression.

Testing ATRA and MEK inhibitor PD0325901 effectiveness in a nude mouse model for human MPNST xenografts

Objective

Malignant peripheral nerve sheath tumors (MPNST) are aggressive sarcomas characterized by high recurrence rates and early metastases. These tumors arise more frequently within neurofibromatosis type 1 (NF1) and present with resistance during standard chemotherapy leading to increased mortality and morbidity in those patients. In vitro all-trans retinoic acid (ATRA) and MEK inhibitors (MEKi) were shown to inhibit tumor proliferation, especially when applied in combination. Therefore, we established a nude mouse model to investigate if treatment of xenografts derived from NF1 associated S462 and T265 MPNST cells respond to ATRA and the MEKi PD0325901.

Results

We demonstrated that human NF1 associated MPNST derived from S462 but not T265 cells form solid subcutaneous tumors in Foxn1 nude mice but not in Balb/c, SHO or Shorn mice. We verified a characteristic staining pattern of human MPNST xenografts by immunohistochemistry. Therapeutic effects of ATRA and/or MEKi PD0325901 on growth of S462 MPNST xenografts in Foxn1 nude mice were not demonstrated in vitro, as we did not observe significant suppression of MPNST growth compared with placebo treatment.

Electronic supplementary material

The online version of this article (10.1186/s13104-018-3630-0) contains supplementary material, which is available to authorized users.

Pigment epithelium-derived factor: a key mediator in bone homeostasis and potential for bone regenerative therapy

Objectives

Pigment epithelium-derived factor (PEDF), a multifunctional endogenous glycoprotein, has a very wide range of biological actions, notably in bone homeostasis. The question has been raised regarding the place of PEDF in the treatment of bone disorders and osteosarcoma, and its potential for tumour growth suppression.

Methods

The PubMed database was used to compile this review.

Key findings

Pigment epithelium-derived factor's actions in osteoid tissues include promoting mesenchymal stem cell commitment to osteoblasts, increasing matrix mineralisation, and promoting osteoblast proliferation. It shows potential to improve therapeutic outcomes in treatment of multiple cancer types and regrowth of bone after trauma or resection in animal studies. PEDF may possibly have a reduced adverse effect profile compared with current osteo-regenerative treatments; however, there is currently very limited evidence regarding the safety or efficacy in human models.

Summary

Pigment epithelium-derived factor is very active within the body, particularly in osseous tissue, and its physiological actions give it potential for treatment of both bone disorders and multiple tumour types. Further research is needed to ascertain the adverse effects and safety profile of PEDF as a therapeutic agent.

Malignant Peripheral Nerve Sheath Tumors State of the Science: Leveraging Clinical and Biological Insights into Effective Therapies

Malignant peripheral nerve sheath tumor (MPNST) is the leading cause of mortality in patients with neurofibromatosis type 1. In 2002, an MPNST consensus statement reviewed the current knowledge and provided guidance for the diagnosis and management of MPNST. Although the improvement in clinical outcome has not changed, substantial progress has been made in understanding the natural history and biology of MPNST through imaging and genomic advances since 2002. Genetically engineered mouse models that develop MPNST spontaneously have greatly facilitated preclinical evaluation of novel drugs for translation into clinical trials led by consortia efforts. Continued work in identifying alterations that contribute to the transformation, progression, and metastasis of MPNST coupled with longitudinal follow-up, biobanking, and data sharing is needed to develop prognostic biomarkers and effective prevention and therapeutic strategies for MPNST.

The pigment epithelium-derived factor (PEDF): an important potential therapeutic agent for infantile hemangioma

In previous studies, the expression and the role of proangiogenic factors in infantile hemangiomas have been well studied. However, the role of angiogenic inhibitors has been revealed rarely. The expression of PEDF, as the strongest and safe endogenous inhibitor, is still unrecognized until the current study. In order to investigate the expression and significance of the pigment epithelium-derived factor (PEDF) in the proliferating and regressing phases of infantile hemangiomas, the expression of PEDF, VEGF, Ki-67, and CD34 protein in hemangioma tissues was examined with immunohistochemical polymer HRP method in 42 cases during the proliferative phase, 40 cases during the regressing phase, and 11 cases of non-involuting congenital hemangiomas (NICHs). Meanwhile, the mRNA expression of these factors was detected with quantitative realtime RT-PCR. We found the protein and mRNA expression of PEDF in regressing phase was significantly higher than those in proliferative phase and NICHs (P < 0.001), while the protein and mRNA expression of VEGF were much lower (P < 0.001). The microvessel density (MVD), Ki-67 changes, and the expression of PEDF and VEGF were found significantly correlated. These results indicated that the reduction of VEGF and increase in PEDF are causative to the evolution of infantile hemangioma. PEDF may play a key role in the spontaneous regression of infantile hemangioma and may become an important potential therapeutic agent for infantile hemangioma.

Pigment epithelium-derived factor enhances tumor response to radiation through vasculature normalization in allografted lung cancer in mice

This study aimed to explore the potential therapeutic effects of the combination of pigment epithelium-derived factor (PEDF) and radiation on lung cancer. The Lewis lung cancer (LLC) allografts in nude mice were treated with radiation, PEDF and PEDF combined with radiation. The morphologic changes of tumor vasculature and the hypoxic fraction of tumor tissues were evaluated. Significant inhibition of tumor growth was observed when radiation was applied between the 3rd and 7th day (the vasculature normalization window) after the initiation of PEDF treatment. During the vasculature normalization window, the tumor blood vessels in PEDF-treated mice were less tortuous and more uniform than those in the LLC allograft tumor treated with phosphate-buffered saline. Meanwhile, the thickness of the basement membrane was remarkably reduced and pericyte coverage was significantly increased with the PEDF treatment. We also found that tumor hypoxic fraction decreased during the 3rd to the 7th day after PEDF treatment, suggesting improved intratumoral oxygenation. Taken together, our results show that PEDF improved the effects of radiation therapy on LLC allografts by inducing a vascular normalization window from the 3rd to the 7th day after PEDF treatment. Our findings provide a basis for treating lung cancer with the combination of PEDF and radiation.