Neuropilin-2–expressing breast cancer cells mitigate radiation-induced oxidative stress through nitric oxide signaling
Ayush Kumar, Hira Lal Goel, Christi A. Silva, Tao Wang, Yansong Geng, Mengdie Wang, Shivam Goel, Kai Hu, Rui Li, Lihua J. Zhu, Jennifer L. Clark, Lindsay M. Ferreira, Michael A. Brehm, Thomas J. FitzGerald, Arthur M. Mercurio
Ayush Kumar, Hira Lal Goel, Christi A. Silva, Tao Wang, Yansong Geng, Mengdie Wang, Shivam Goel, Kai Hu, Rui Li, Lihua J. Zhu, Jennifer L. Clark, Lindsay M. Ferreira, Michael A. Brehm, Thomas J. FitzGerald, Arthur M. Mercurio
View: Text | PDF
Research Article Cell biology Oncology

Neuropilin-2–expressing breast cancer cells mitigate radiation-induced oxidative stress through nitric oxide signaling

Abstract

The high rate of recurrence after radiation therapy in triple-negative breast cancer (TNBC) indicates that novel approaches and targets are needed to enhance radiosensitivity. Here, we report that neuropilin-2 (NRP2), a receptor for vascular endothelial growth factor (VEGF) that is enriched on subpopulations of TNBC cells with stem cell properties, is an effective therapeutic target for sensitizing TNBC to radiotherapy. Specifically, VEGF/NRP2 signaling induces nitric oxide synthase 2 (NOS2) transcription by a mechanism dependent on Gli1. NRP2-expressing tumor cells serve as a hub to produce nitric oxide (NO), an autocrine and paracrine signaling metabolite, which promotes cysteine-nitrosylation of Kelch-like ECH-associated protein 1 (KEAP1) and, consequently, nuclear factor erythroid 2-related factor 2–mediated (NFE2L2-mediated) transcription of antioxidant response genes. Inhibiting VEGF binding to NRP2, using a humanized mAb, results in NFE2L2 degradation via KEAP1, rendering cell lines and organoids vulnerable to irradiation. Importantly, treatment of patient-derived xenografts with the NRP2 mAb and radiation resulted in significant tumor necrosis and regression compared with radiation alone. Together, these findings reveal a targetable mechanism of radioresistance, and they support the use of NRP2 mAb as an effective radiosensitizer in TNBC.

Authors

Ayush Kumar, Hira Lal Goel, Christi A. Silva, Tao Wang, Yansong Geng, Mengdie Wang, Shivam Goel, Kai Hu, Rui Li, Lihua J. Zhu, Jennifer L. Clark, Lindsay M. Ferreira, Michael A. Brehm, Thomas J. FitzGerald, Arthur M. Mercurio

×

Figure 8

Hypofractionated radiation with aNRP2 promoted tumor regression in PDX model.

Options: View larger image (or click on image) Download as PowerPoint
Hypofractionated radiation with aNRP2 promoted tumor regression in PDX m...
(A) Schematic of the fractionated radiation and antibody-treatment schedules. (B) Tumor volumes in mice that had been implanted orthotopically with a human TNBC PDX in NSG mice. The mice were divided into 4 groups of 5 mice each. When tumors reached approximately 125–150 mm3, the mice were treated with either IgG (10 mg/kg), aNRP2-10 (10 mg/kg), IgG 8Gyx3, or aNRP2-10 8Gyx3. Antibody treatments were given as i.p. injections. The waterfall plot shows the percentage change in growth of the tumor from day –1 to day 15 for each individual mouse. Molecular and histological analysis of the tumors were done on day 15 after the first radiation dose. ***P < 0.001; ****P < 0.0001. (C) The tumor weights from the radiation-treated groups (n = 5), and percentage of tumor necrosis based on H&E section of the tumors from the radiation-treated groups (n = 3). **P < 0.01; ***P < 0.001. (D) Immunoblot of γ-H2AX from 3 mice in each of the fractionated radiation-treated groups. (E) NOS2, HMOX1, and PRDX1 mRNA expression was quantified by qPCR from 3 mice in each of the radiation-treated groups. *P < 0.05; ***P < 0.001. Data are presented as means ± SD (C and E). Statistical analysis was performed using 2-tailed Student’s t test (C and E) or 1-way ANOVA multiple comparisons (B).