Dual targeting macrophages and microglia is a therapeutic vulnerability in models of PTEN-deficient glioblastoma
Yang Liu, Junyan Wu, Hinda Najem, Yiyun Lin, Lizhi Pang, Fatima Khan, Fei Zhou, Heba Ali, Amy B. Heimberger, Peiwen Chen
Yang Liu, Junyan Wu, Hinda Najem, Yiyun Lin, Lizhi Pang, Fatima Khan, Fei Zhou, Heba Ali, Amy B. Heimberger, Peiwen Chen
View: Text | PDF
Research Article Oncology

Dual targeting macrophages and microglia is a therapeutic vulnerability in models of PTEN-deficient glioblastoma

Abstract

Tumor-associated macrophages and microglia (TAMs) are critical for tumor progression and therapy resistance in glioblastoma (GBM), a type of incurable brain cancer. We previously identified lysyl oxidase (LOX) and olfactomedin like-3 (OLFML3) as essential macrophage and microglia chemokines, respectively, in GBM. Here, single-cell transcriptomics and multiplex sequential immunofluorescence followed by functional studies demonstrate that macrophages negatively correlate with microglia in the GBM tumor microenvironment. LOX inhibition in PTEN-deficient GBM cells upregulates OLFML3 expression via the NF-κB-PATZ1 signaling pathway, inducing a compensatory increase of microglia infiltration. Dual targeting macrophages and microglia via inhibition of LOX and the CLOCK-OLFML3 axis generates potent antitumor effects and offers a complete tumor regression in more than 60% of animals when combined with anti-PD1 therapy in PTEN-deficient GBM mouse models. Thus, our findings provide a translational triple therapeutic strategy for this lethal disease.

Authors

Yang Liu, Junyan Wu, Hinda Najem, Yiyun Lin, Lizhi Pang, Fatima Khan, Fei Zhou, Heba Ali, Amy B. Heimberger, Peiwen Chen

×

Figure 5

LOX regulates OLFML3 expression through regulating the NF-κB-PATZ1 signaling axis.

Options: View larger image (or click on image) Download as PowerPoint
LOX regulates OLFML3 expression through regulating the NF-κB-PATZ1 signa...
(A) GSEA analysis on RNA-seq data of U87 cells with LOX shRNA knockdown (shLOX) versus shRNA control (shC) shows top 10 enriched oncogenic signaling pathways. (B) Immunoblots for P-P65, P65, and LOX in lysates of U87 and PTEN-KO SF763 cells expressing shC and shLOX. (C) Relative mRNA expression of OLFML3 in PTEN-KO SF763 cells expressing shC and shLOX treated with or without P65 inhibitor (P65i) SC75741 (5 μM). n = 3 independent samples. Student’s t test. (D) Identification of 22 overlapping transcription factors (TFs) in TCGA GBM tumors (LOX-low versus -high) and U87 cells (shLOX versus shC). (E) Relative mRNA expression of 10 TFs in PTEN-KO SF763 cells expressing shC and shLOX. n = 3 independent samples. 1-way ANOVA test. (F) Relative mRNA expression of the 10 TFs in U87 cells treated with or without LOX inhibitor BAPN (200 μM). n = 3 independent samples. Student’s t test. (G) Immunoblots for PATZ1 in lysates of PTEN-KO SF763 cells expressing shC and shLOX. (H) Relative mRNA expression of PATZ1 in PTEN-KO SF763 cells expressing shC and shLOX and treated with or without P65i SC75741 (5 μM). n = 3 independent samples. Student’s t test. (I) Schematic of designing ChIP-qPCR primers based on 3 potential binding sites. (J) Quantification of PATZ1 ChIP-qPCR in the OLFML3 promoter of PTEN-KO SF763 cells. IgG was used as the control. n = 3 independent samples. Student’s t test. (K) Immunoblots for OLFML3 in lysates of PTEN-KO SF763 cells with or without PATZ1 overexpression (OE) and treated with or without P65 activator (+). (L) Immunoblots for OLFML3 in lysates of PTEN-WT SF763 cells expressing shC and shPATZ1 treated with or without P65i SC75741 (5 μM). *P < 0.05; **P < 0.01; ***P < 0.001; n.s., not significant (P > 0.05).