Chordoma recruits and polarizes tumor-associated macrophages via secreting CCL5 to promote malignant progression

Abstract

BackgroundChordoma is an extremely rare, locally aggressive malignant bone tumor originating from undifferentiated embryonic remnants. There are no effective therapeutic strategies for chordoma. Herein, we aimed to explore cellular interactions within the chordoma immune microenvironment and provide new therapeutic targets.MethodsSpectrum flow cytometry and multiplex immunofluorescence (IF) staining were used to investigate the immune microenvironment of chordoma. Cell Counting Kit-8, Edu, clone formation, Transwell, and healing assays were used to validate tumor functions. Flow cytometry and Transwell assays were used to analyze macrophage phenotype and chemotaxis alterations. Immunohistochemistry, IF, western blot, PCR, and ELISA assays were used to analyze molecular expression. An organoid model and a xenograft mouse model were constructed to investigate the efficacy of maraviroc (MVC).ResultsThe chordoma immune microenvironment landscape was characterized, and we observed that chordoma exhibits a typical immune exclusion phenotype. However, macrophages infiltrating the tumor zone were also noted. Through functional assays, we demonstrated that chordoma-secreted CCL5 significantly promoted malignancy progression, macrophage recruitment, and M2 polarization. In turn, M2 macrophages markedly enhanced the proliferation, invasion, and migration viability of chordoma. CCL5 knockdown and MVC (CCL5/CCR5 inhibitor) treatment both significantly inhibited chordoma malignant progression and M2 macrophage polarization. We established chordoma patient-derived organoids, wherein MVC exhibited antitumor effects, especially in patient 4, with robust killing effect. MVC inhibits chordoma growth and lung metastasis in vivo.ConclusionsOur study implicates that the CCL5–CCR5 axis plays an important role in the malignant progression of chordoma and the regulation of macrophages, and that the CCL5–CCR5 axis is a potential therapeutic target in chordoma.

CCL5 promotes the proliferation and metastasis of bladder cancer via the JAK2/STAT3 signaling pathway

“…Moreover, we found CCL5 activation of tumor progression may be related to the JAK2/STAT3 pathways. This association between CCL5 and the JAK2/STAT3 pathway with malignancies, including BC as indicated by our results, offers intriguing options for diagnostic indicators and prognostic biomarkers, as well as potential therapeutic targets for BC and other diseases ( 44 , 45 ). For example, an entry inhibitor based on CCR5 approved by the United States Food and Drug Administration in 2007 known as maraviroc (MRV) appears to promote the internalization of CCR5, does not rely on cellular signaling, and is clinically beneficial for HIV patients with mild side effects.…”

Animal model considerations for chordoma research: reproducing the tumor microenvironment in vivo with humanized mice

“…As previously discussed, TME plays a crucial role in tumor progression, and this is particularly true for the TIME, which can significantly influence the malignancy of tumor cells, including chordoma. For instance, tumor-associated macrophages, which are among the most prevalent cell types within the TIME and infiltrate the chordoma tumor parenchyma, are highly versatile macrophages capable of transitioning between M1 and M2 phenotypes depending on the specific requirements of the tumor ( 136 ). Therefore, it has been suggested that one of the ways to target cancer is to enhance immune regulation ( 137 , 138 ).…”

“…Besides the PD1/PDL1 pathway, TGF-beta-related genes, HHLA2, and cytotoxic T-lymphocyte antigen-4 (CTLA-4) are among some of the immune-associated molecules analyzed so far ( 128 , 129 , 131 ). Other examples of interactions between chordoma and the immune system are the above mentioned plastic macrophages that, via the ccl5/ccr5 axis, are recruited and polarized by chordoma to enhance the proliferation, invasion and migration capabilities of chordoma ( 136 ); galectin-9 that interacts with TIM3-positive TILs and that promotes cell apoptosis ( 141 ) and the expression of CTLA-4, a promising immune checkpoint inhibitor target that it is expressed by the TILs that are infiltrating chordoma ( 129 ). We can learn from these examples that chordoma can evade the immune system by evading the recognition via antigen restriction by the TIL and marrow-infiltrating lymphocytes (MIL), or by directly interacting with the immune system and inhibiting it or by causing T cell exhaustion, as happens in many other cancers ( 142 ).…”

“…As we already mentioned, Xu et al. ( 136 ) found that ccl5 and M2 macrophages drive chordoma growth, and while they acquired this data through use of an immunodeficient mouse, the lack of a humanized mouse limited the team’s ability to assess the underlying molecular characteristics. Another research team from Northwestern University has also proposed a project to create a humanized mouse for the study of chordoma therapies ( 160 ).…”

Combination of Genomic Landsscape and 3D Culture Functional Assays Bridges Sarcoma Phenotype to Target and Immunotherapy

“…In particular, chordoma organoids showed the typical immune exclusion phenotype and macrophage M2 polarisation observed in patients. Studies of the culture media from organoids detected the secretion of CCL5 chemokine [108] and its knockdown, and treatment with MVC (a CCL5/CCR5 inhibitor) both significantly inhibited the progression of malignant chordoma and M2 macrophage polarisation. This suggests that the CCL5-CCR5 axis is a potential therapeutic target and further supports the notion that organoids are a valid model for studying the microenvironment of rare tumours [108].…”