KLK3 in the Regulation of Angiogenesis—Tumorigenic or Not?

In this focused review, we address the role of the kallikrein-related peptidase 3 (KLK3), also known as prostate-specific antigen (PSA), in the regulation of angiogenesis. Early studies suggest that KLK3 is able to inhibit angiogenic processes, which is most likely dependent on its proteolytic activity. However, more recent evidence suggests that KLK3 may also have an opposite role, mediated by the ability of KLK3 to activate the (lymph)angiogenic vascular endothelial growth factors VEGF-C and VEGF-D, further discussed in the review.

Pediatric choroidal neovascularization: Etiology and treatment outcomes with anti-vascular endothelial growth factors

Purpose: To describe the etiology and treatment outcomes of choroidal neovascularization (CNV) in a pediatric population with intravitreal anti-vascular endothelial growth factors (VEGF) Methods: Retrospective single center interventional case series. A total of 26 eyes of 23 consecutive pediatric patients with CNV of various etiologies were treated with intravitreal injection of anti-VEGF agents. Results: There were 15 males (65.2%) and eight females (34.8%), diagnosed with CNV during the study period. The mean age at presentation with CNV was 11.7 ± 3.3 years, (range 4–16 years) and the mean follow was 28.1 ± 18 months, (range 8–72 months). Inflammatory CNV was the most common etiology. The mean best corrected visual acuity (BCVA) and mean central macular thickness (CMT) at presentation, were logMAR 0.8 ± 0.3 and 367.6 ± 134.8 µm respectively. At the final visit, CNV in all eyes remained regressed with significant improvement in mean BCVA to logMAR 0.4 ± 0.4 ( p < 0.0001) and mean CMT to 242.5 ± 82.4 µm ( p < 0.0001). A mean of two intravitreal injections per eye was required for CNV regression. Conclusion: Intravitreal anti-VEGF therapy for pediatric CNV is an effective treatment in majority of affected eyes.

Non-immediate drug hypersensitivity reactions secondary to intravitreal anti-vascular endothelial growth factors

Purpose To describe a series of non-immediate drug hypersensitivity reactions after intravitreal anti-vascular endothelial growth factors (anti-VEGFs). Patients and methods Retrospective report of 6 patients with cutaneous non-immediate drug hypersensitivity reactions following intravitreal anti-VEGF injections, 4 after ranibizumab, 1 after bevacizumab and 1 after aflibercept. Results Clinical manifestations ranged from mild maculopapular rash, purpura to severe generalized erythroderma, with or without systemic involvement such as microscopic hematuria and proteinuria or fever. In two out of the six patients, reintroduction of either the same or an alternative anti-VEGF drug did induce a recurrence of the drug hypersensitivity reaction, while 4 patients showed no recurrence. Conclusion Cutaneous non-immediate drug hypersensitivity reactions secondary to intravitreal anti-VEGF may occur. Continuation of the same drug or switch to another anti-VEGF may either induce recurrence or be well supported by the patient. The decision of drug discontinuation should be guided by the severity of the disease.

Coordinating Effect of VEGFC and Oleic Acid Participates to Tumor Lymphangiogenesis

In cancer, the lymphatic system is hijacked by tumor cells that escape from primary tumor and metastasize to the sentinel lymph nodes. Tumor lymphangiogenesis is stimulated by the vascular endothelial growth factors-C (VEGFC) after binding to its receptor VEGFR-3. However, how VEGFC cooperates with other molecules to promote lymphatics growth has not been fully determined. We showed that lymphangiogenesis developed in tumoral lesions and in surrounding adipose tissue (AT). Interestingly, lymphatic vessel density correlated with an increase in circulating free fatty acids (FFA) in the lymph from tumor-bearing mice. We showed that adipocyte-released FFA are uploaded by lymphatic endothelial cells (LEC) to stimulate their sprouting. Lipidomic analysis identified the monounsaturated oleic acid (OA) as the major circulating FFA in the lymph in a tumoral context. OA transporters FATP-3, -6 and CD36 were only upregulated on LEC in the presence of VEGFC showing a collaborative effect of these molecules. OA stimulates fatty acid β-oxidation in LECs, leading to increased AT lymphangiogenesis. Our results provide new insights on the dialogue between tumors and adipocytes via the lymphatic system and identify a key role for adipocyte-derived FFA in the promotion of lymphangiogenesis, revealing novel therapeutic opportunities for inhibitors of lymphangiogenesis in cancer.