Faculty, Staff and Student Publications

Publication Date

5-6-2025

Journal

Breast Cancer Research

Abstract

Background: Tumor-associated macrophages (TAMs) are key promoters of inflammatory breast cancer (IBC), the most aggressive form of breast cancer. The receptor tyrosine kinase AXL is highly expressed in various cancer types, including IBC, but its role in TAMs remains unexplored.

Methods: We examined the effects of AXL inhibitor TP-0903 on tumor growth and tumor microenvironment (TME) component M2 macrophages (CD206+) in IBC and triple-negative breast cancer mouse models using flow cytometry and immunohistochemical staining. Additionally, we knocked out AXL expression in human THP-1 monocytes and evaluated the effect of AXL signaling on immunosuppressive M2 macrophage polarization and IBC cell growth and migration. We then investigated the underlying mechanisms through RNA sequencing analysis. Last, we performed CIBERSORT deconvolution to analyze the association between AXL expression and tumor-infiltrating immune cell types in tumor samples from the Inflammatory Breast Cancer International Consortium.

Results: We found that inhibiting the AXL pathway significantly reduced IBC tumor growth and decreased CD206+ macrophage populations within tumors. Mechanistically, our in vitro data showed that AXL promoted M2 macrophage polarization and enhanced the secretion of immunosuppressive chemokines, including CCL20, CCL26, and epiregulin, via the transcription factor STAT6 and thereby accelerated IBC cell growth and migration. RNA sequencing analysis further indicated that AXL signaling in immunosuppressive M2 macrophages regulated the expression of molecules and cytokines, contributing to an immunosuppressive TME in IBC. Moreover, high AXL expression was correlated with larger populations of immunosuppressive immune cells but smaller populations of immunoactive immune cells in tissues from patients with IBC.

Conclusions: AXL signaling promotes IBC growth by inducing M2 macrophage polarization and driving the secretion of immunosuppressive molecules and cytokines via STAT6 signaling, thereby contributing to an immunosuppressive TME. Collectively, these findings highlight the potential of targeting AXL signaling as a novel therapeutic approach for IBC that warrants further investigation in clinical trials.

Keywords

Receptor Protein-Tyrosine Kinases, Humans, Proto-Oncogene Proteins, Female, Animals, Axl Receptor Tyrosine Kinase, Mice, Tumor Microenvironment, Tumor-Associated Macrophages, Inflammatory Breast Neoplasms, Disease Progression, Cell Line, Tumor, Macrophages, Signal Transduction, Macrophage Activation, Cell Movement, Benzocycloheptenes, Cell Proliferation, Gene Expression Regulation, Neoplastic

DOI

10.1186/s13058-025-02015-8

PMID

40329335

PMCID

PMC12057249

PubMedCentral® Posted Date

5-6-2025

PubMedCentral® Full Text Version

Post-print

Published Open-Access

yes

Share

COinS
 
 

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.