PEDF effectively decreases VEGF to PEDF messenger RNA ratio of the inner edge of rat hepatocellular carcinoma induced by diethyl nitrosamine - an "in vivo" study

Pigment Epithelium-Derived Factor Promotes the Growth and Migration of Human Esophageal Squamous Cell Carcinoma

Pigment epithelium-derived factor (PEDF) is an oncogene found in various types of cancers. However, how PEDF affects the development of human esophageal squamous cell carcinoma (ESCC) is unknown. This study investigates the role of PEDF in ESCC cell proliferation, migration, and cell cycle both in vitro and in vivo. The PEDF expression was examined in patient tumor samples and ESCC cell lines. Short hairpin RNA technology was used to inhibit the PEDF expression in ESCC EC9706 and KYSE150 cells. In vitro cell proliferation and migration assays were performed. The effects of PEDF on tumor growth and progression were examined in vivo in murine subcutaneous xenograft tumor models. It was found that PEDF was overexpressed in esophageal cancer cells and patient tumor tissues compared to normal control samples. PEDF enhanced cell cycle progression and inhibited cell apoptosis. Knock down of PEDF inhibited esophageal cell proliferation and migration in vitro. Moreover, Inhibition of PEDF significantly reduced tumor growth and tumor size in vivo. These results indicate that PEDF induce tumorigenesis in ESCC and can be a potential therapeutic target for cancer treatment.

Pigment epithelium-derived factor/vascular endothelial growth factor ratio plays a crucial role in the spontaneous regression of infant hemangioma and in the therapeutic effect of propranolol

Infantile hemangioma (IH) is a benign tumor that is formed by aberrant angiogenesis and that undergoes spontaneous regression over time. Propranolol, the first-line therapy for IH, inhibits angiogenesis by downregulating activation of the vascular endothelial growth factor (VEGF) pathway, which is hyperactivated in IH. However, this treatment is reportedly ineffective for 10% of tumors, and 19% of patients relapse after propranolol treatment. Both pro-angiogenic and anti-angiogenic factors regulate angiogenesis, and pigment epithelium-derived factor (PEDF) is the most effective endogenous anti-angiogenic factor. PEDF/VEGF ratio controls many angiogenic processes, but its role in IH and the relationship between this ratio and propranolol remain unknown. Results of the present study showed that the PEDF/VEGF ratio increased during the involuting phase of IH compared with the proliferating phase. Similarly, in hemangioma-derived endothelial cells (HemEC), which were isolated with magnetic beads, increasing the PEDF/VEGF ratio inhibited proliferation, migration, and tube formation and promoted apoptosis. Mechanistically, the VEGF receptors (VEGFR1 and VEGFR2) and PEDF receptor (laminin receptor, LR) were highly expressed in both IH tissues and HemEC, and PEDF inhibited HemEC function by binding to LR. Interestingly, we found that propranolol increased the PEDF/VEGF ratio but did so by lowering VEGF expression rather than by upregulating PEDF as expected. Furthermore, the combination of PEDF and propranolol had a more suppressive effect on HemEC. Consequently, our results suggested that the PEDF/VEGF ratio played a pivotal role in the spontaneous regression of IH and that the combination of PEDF and propranolol might be a promising treatment strategy for propranolol-resistant IH.

Evaluation of VEGF and PEDF in prostate cancer: A preliminary study in serum and biopsies

Vascular endothelial growth factor (VEGF) and the pigment epithelium-derived factor (PEDF) serve an important role in prostate cancer (PCa). The aim of the present study was to evaluate whether the levels of VEGF and PEDF in serum are associated with the severity of PCa, and whether they can differentiate from patients with benign prostatic hyperplasia (BPH). Two groups of patients were recruited, patients with PCa or BPH that were newly diagnosed without other comorbidities, and were compared with healthy individuals. The levels of VEGF and PEDF were measured by ELISA in serum, and by immunohistochemistry in biopsies. A correlation analysis was performed for the values in biopsies and serum, comparing the VEGF/PEDF ratio, total-prostate-specific antigen (t-PSA) levels and the status of each sample as acinar Ad (Gleason score) or as benign hyperplasia. The results demonstrated that serum levels of VEGF, PEDF, and t-PSA between PCa and BPH were similar to each other, but different to healthy individuals (P<0.05). The VEGF/PEDF ratio in serum had a significant difference between acinar Ad with Gleason score 8–10 and BPH groups (P<0.05). The VEGF and PEDF immunostaining intensities were correlated with its circulating levels in all cases of PCa, but not in BPH. These preliminary results suggest that VEGF and PEDF levels by themselves or in combination with t-PSA did not differentiate between malignant, and benign prostate diseases. However, there was a significant difference observed in the VEGF/PEDF ratio in serum between the groups, suggesting that it may be used as an index for diagnosis and prognosis in a personalized manner, although more studies are necessary.