scholarly journals The Role of a Proprotein Convertase Inhibitor in Reactivation of Tumor-Associated Macrophages and Inhibition of Glioma Growth

2020 ◽  
Vol 17 ◽  
pp. 31-46
Author(s):  
Mélanie Rose ◽  
Marie Duhamel ◽  
Soulaimane Aboulouard ◽  
Firas Kobeissy ◽  
Emilie Le Rhun ◽  
...  
2021 ◽  
Author(s):  
Nai-Wei Yao ◽  
Hsiu-Ting Lin ◽  
Ya-Lin Lin ◽  
Khamushavalli Geeviman ◽  
Fang Liao ◽  
...  

Abstract Background: Glioblastoma is the most aggressive subtype of brain tumors. The major component of tumor microenvironment in glioblastoma is tumor-associated macrophages (TAMs), which are associated with enhanced malignancy of glioblastoma. The polarization of macrophages to the pro-inflammatory M1 or anti-inflammatory M2 subtypes governed by the context of tumor microenvironment may dictate the aggressiveness and outcome of glioblastoma. Given that the immune responses to tumors vary distinctively among individuals due to intrinsic, environmental and genetic factors and that TAMs display a high level of diversity and plasticity, we aimed to examine the effects of differential polarization of TAMs on the glioblastoma development by implanting C6 glioma into brains of Sprague–Dawley (SD) and Wistar rats; these two rats have different genetic background and host microenvironment during tumor development. Methods: Sprague–Dawley (SD) and Wistar rats were implanted with C6 glioma in the brain. The measurement of tumor volumes, tumor morphology and tumor growth in C6 glioma implanted brains were measured by multi-parametric magnetic resonance imaging (MRI). Immunofluorescence staining was performed to analyze tumor angiogenesis and M1 and M2 TAMs in C6 gliomas. Results: By multi-parametric MRI measurement, C6 gliomas developed in the SD rats were characterized with enlarged tumors, accompanied with shorter animal survival. In comparison to the gliomas in Wistar rats, the accelerated tumor growth in SD rats was associated with greater extent of angiogenesis accompanied with higher levels of VEGF/VEGFR2. In support, C6 gliomas in SD rats were filtrated with TAMs characterized with a higher M2/M1 ratio, in contrast to the TAMs of a high M1/M2 ratio in Wistar rats. Attempts were made to shift the M2/M1 balance. Administration of the cytokine IFN-γ that induces M1 TAMs to SD rats greatly suppressed glioma formation, accompanied with a remarkable increase of M1 TAMs. Administration of the cytokines IL-4 plus IL-10 that induces M2 TAMs significantly promoted glioma growth in the Wistar rats, associated with an increase in the M2 TAMs. Conclusions: These results demonstrate an important role of TAMs in glioma pathogenesis and the crucial role of microenvironment in dictating the polarization of TAMs, suggesting that targeting or repolarization of TAMs may serve as an effective intervention for gliomas.


Metabolites ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 180
Author(s):  
Christina Mertens ◽  
Matthias Schnetz ◽  
Claudia Rehwald ◽  
Stephan Grein ◽  
Eiman Elwakeel ◽  
...  

Macrophages supply iron to the breast tumor microenvironment by enforced secretion of lipocalin-2 (Lcn-2)-bound iron as well as the increased expression of the iron exporter ferroportin (FPN). We aimed at identifying the contribution of each pathway in supplying iron for the growing tumor, thereby fostering tumor progression. Analyzing the expression profiles of Lcn-2 and FPN using the spontaneous polyoma-middle-T oncogene (PyMT) breast cancer model as well as mining publicly available TCGA (The Cancer Genome Atlas) and GEO Series(GSE) datasets from the Gene Expression Omnibus database (GEO), we found no association between tumor parameters and Lcn-2 or FPN. However, stromal/macrophage-expression of Lcn-2 correlated with tumor onset, lung metastases, and recurrence, whereas FPN did not. While the total iron amount in wildtype and Lcn-2−/− PyMT tumors showed no difference, we observed that tumor-associated macrophages from Lcn-2−/− compared to wildtype tumors stored more iron. In contrast, Lcn-2−/− tumor cells accumulated less iron than their wildtype counterparts, translating into a low migratory and proliferative capacity of Lcn-2−/− tumor cells in a 3D tumor spheroid model in vitro. Our data suggest a pivotal role of Lcn-2 in tumor iron-management, affecting tumor growth. This study underscores the role of iron for tumor progression and the need for a better understanding of iron-targeted therapy approaches.


2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi204-vi204
Author(s):  
Rohit Rao ◽  
Rong Han ◽  
Sean Ogurek ◽  
Lai Man Wu ◽  
Liguo Zhang ◽  
...  

Abstract Tumor-associated macrophages/microglia (TAMs) are prominent microenvironment components in human glioblastoma (GBM) that are potential targets for anti-tumor therapy. However, TAM depletion by CSF1R inhibition showed mixed results in clinical trials. We hypothesized that GBM subtype-specific tumor microenvironment convey distinct sensitivities to TAM targeting. We generated syngeneic PDGFB-driven and RAS-driven GBM models that resemble proneural-like and mesenchymal-like gliomas, and determined the effect of TAM targeting by CSF1R inhibitor PLX3397 on glioma growth and progression. We also investigated the co-targeting of TAMs and angiogenesis on PLX3397-resistant RAS-driven GBM. Using single-cell transcriptomic profiling, we further explored differences in tumor microenvironment compositions and functions between the proneural-like and mesenchymal-like glioma models. We found that the growth of PDGFB-driven tumors was markedly inhibited by PLX3397. In contrast, depletion of TAMs at the early phase accelerated RAS-driven tumor growth and had no effects on other proneural and mesenchymal human GBM models. In addition, PLX3397-resistant RAS-driven tumors did not respond to PI3K signaling inhibition. Single-cell transcriptomic profiling revealed that PDGFB-driven gliomas induced expansion and activation of pro-tumor microglia, whereas mesenchymal RAS-driven gliomas elicited TAMs enriched in pro-inflammatory and angiogenic signaling. Co-targeting of TAMs and angiogenesis decreased cell proliferation and tumor mass in RAS-driven gliomas. Our work identifies functionally distinct TAM subpopulations in the growth of different glioma subtypes. Notably, we uncover a potential responsiveness of resistant mesenchymal-like gliomas to combined anti-angiogenic therapy and CSF1R inhibition. These data highlight the importance of microenvironment landscape characterization to optimally stratify glioma patients for TAM-targeted therapy.


2021 ◽  
Vol 22 (16) ◽  
pp. 8470
Author(s):  
Hui Wang ◽  
Tian Tian ◽  
Jinhua Zhang

Colorectal cancer (CRC) is a malignant tumor in the digestive system whose incidence and mortality is high-ranking among tumors worldwide. The initiation and progression of CRC is a complex process involving genetic alterations in cancer cells and multiple factors from the surrounding tumor cell microenvironment. As accumulating evidence has shown, tumor-associated macrophages (TAMs)—as abundant and active infiltrated inflammatory cells in the tumor microenvironment (TME)—play a crucial role in CRC. This review focuses on the different mechanisms of TAM in CRC, including switching of phenotypical subtypes; promoting tumor proliferation, invasion, and migration; facilitating angiogenesis; mediating immunosuppression; regulating metabolism; and interacting with the microbiota. Although controversy remains in clinical evidence regarding the role of TAMs in CRC, clarifying their significance in therapy and the prognosis of CRC may shed new light on the optimization of TAM-centered approaches in clinical care.


2017 ◽  
Vol 13 (1) ◽  
pp. 20-26
Author(s):  
O. V. Kovaleva ◽  
G. D. Efremov ◽  
D. S. Mikhaylenko ◽  
B. Ya. Alekseev ◽  
A. N. Grachev

2013 ◽  
Vol 62 (12) ◽  
pp. 1757-1768 ◽  
Author(s):  
Matteo Santoni ◽  
Francesco Massari ◽  
Consuelo Amantini ◽  
Massimo Nabissi ◽  
Francesca Maines ◽  
...  

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