Modulation of Interleukin-5 and RAS signaling pathways for tumor control in Neurofibromatosis Type-1

Neurofibromatosis type 1 (NF1) is a tumor predisposition syndrome which causes tumors in the central and peripheral nervous system. Mutations in neurofibromin gene lead to dysregulation of the RAS/MAPK pathway. Initially, RNA sequencing of peripheral blood and bone marrow from NF1 patients and healthy donors was done to identify differentially expressed genes (DEGs) in these groups. In vitro assays were performed to evaluate the effect of IL-5 and IL-5 inhibitor, IL-4/IL-13 Inhibitor, as well as TGFβ1 and TGFβ inhibitor. sNF96.2 was selected as NF1 cell line and human fibroblast cell line was used as a control. The major DEGs clustered in pathways related to neurodegeneration, inflammation, and cell proliferation. Our results suggest that cytokines such as IL-5, IL-4, and IL-13 play important role in NF1, which are involved in tumor growth through the activation of the RAS and NFkβ signaling pathways. qPCR results confirm that treatment with IL-5 inhibitor, such as YM-90709, down regulate these cytokines, as well as expression of genes in the RAS pathway, consequently inhibiting NF1 cell proliferation. In addition, the inhibition of IL-4 and IL-13 signaling with Dupilumab showed significant decrease of neurofibroma development displayed by reduced tumor cell survival. Based on the ELISA results, IL-5 was absent in substrate of IL-5 treated NF1 cells, but it is detected in NF1 cells treated with an IL-5 inhibitor, while IL-4 was present in substrate of Dupilumab-treated NF1 cells and stem cell factor (SCF) was detected in substrate of SCF-treated NF1 cells. Moreover, the involvement of SCF cytokine in promoting NF1 tumor growth was evident. TGF-β was recognized as a modulator of immune responses and suppresses NF1 cell viability. In conclusion, our findings introduce therapeutic potential through targeting inflammatory pathways, particularly through inhibition of IL-5, IL-4, and SCF signaling, in NF1. These insights open the door for new immunotherapeutic strategies, such as IL-5 inhibitors (e.g., Mepolizumab) or IL-4/IL-13 inhibitors (e.g., Dupilumab), for the treatment of NF1-related tumors and associated inflammatory conditions. Further clinical trials are needed to warrant the efficacy of this approach.