The ELK3-CXCL16 axis regulates NK cell cytotoxicity via the chemotactic activity of CXCL16 in TNBC

ABSTRACT: Background Triple-negative breast cancer (TNBC) is the most challenging subtype of breast cancer because of its aggressive behavior and the limited therapeutic strategies available. In the last decade, immunotherapy has become a promising treatment to prolong survival in advanced solid cancers including TNBC. However, the efficacy of immunotherapy in solid cancers remains limited because solid tumors contain few tumor-infiltrating lymphocytes. Methods A proteome profiler array was performed to identify secreted CXCL16 protein, the expression of which is regulated by ELK3 to control natural killer (NK) cell-mediated cytotoxicity. The correlation between ELK3 and CXCL16 was investigated by microarray and TCGA data analysis. NK cell cytotoxicity and migration assays were performed to examine the role of ELK3-CXCL16 in regulating the anticancer effect in TNBC. CXCL16-mediated NK cell recruitment and NK cell cytotoxicity were examined in an experimental metastasis mouse model and in an MDA-MB231 orthotopic mouse model. Results We show that targeting the ETS transcription factor ELK3 recruits immune cells including NK cells into tumors via the chemotactic activity of the chemokine. ELK3 depletion upregulated CXCL16 expression, thereby inducing NK cell recruitment to tumors and increasing NK cell cytotoxicity in TNBC . In silico analysis showed that ELK3 is negatively correlated with CXCL16 expression in breast cancer patient samples. Low expression of ELK3 and high expression of CXCL16 were associated with a better prognosis. Low expression of ELK3 and high expression of CXCL16 were associated with increased expression of NK cell-related genes. Conclusions The ELK3-CXCL16 axis regulates NK cell recruitment and increases NK cell cytotoxicity, suggesting that targeting the ELK3 gene could be an adjuvant strategy for increasing the efficacy of immunotherapy in TNBC.

ORGANISM(S): Homo sapiens

PROVIDER: GSE208584 | GEO | 2022/07/20

REPOSITORIES: GEO