Research Assistant Professor Loyola University Chicago Maywood, Illinois, United States
Disclosure(s):
Lijie Zhai, PhD: No financial relationships to disclose
Introduction/Rationale: Complement factor H (CFH) is a pivotal inhibitory modulator in complement alternative activation pathway. Our previous study has shown that tumor cell-derived CFH enhances both regulatory T cells and myeloid derived suppressor cells in the glioblastoma (GBM) microenvironment. Overexpression of CFH in GBM cells resulted in significantly decreased survival in murine models of GBM. Based on these findings, here we aim to test the hypothesis whether inhibition of tumor cell originated CFH could suppress tumor growth, providing further rationale for CFH-targeted GBM therapy.
Methods: Human glioma cell line U87 cells were transduced with lentiviral particles encoding either CFH-specific CRISPR-CAS9 or scramble control. CFH depleted U87 cells were selected and verified by Western Blot. In vitro cell proliferation rate was measured by the Cell Counting Kit 8. Nude mice (B6.Cg-Foxn1/nu/J) were intracranially injected with the parental (parental, n=8), scramble control (scramble, n=8) and the CFH-depleted (KO, n=8) U87 cells, respectively and monitored for survival. Comparison between multiple experimental groups was conducted using one-way ANNOVA and Kaplan-Meier curve was used to compare the survival rate between multiple groups with Bonferroni correction.
Results: Depletion of CFH resulted in significant decrease of in vitro proliferation of U87 cells (parental vs. KO, P < 0.001, scramble vs. KO, P< 0.001, parental vs. scramble, ns). Mice intracranially injected with CFH-depleted U87 cells had a dramatically increased survival rate with median overall survival (mOS) at 41.5 days (P < 0.0001) in comparison to mOS=29 days for the parental group and mOS=25.5 days for the scramble group.
Conclusion: Data from current study demonstrates that genetic depletion of tumor cell-derived CFH represents a promising approach for GBM targeted therapy. Further mechanistic investigation is warranted to delineate the molecular underpinning of CFH-mediated tumorigenesis and immunosuppression in GBM.
