Inhibiting CCR3 expands cancer stem cells via c-Myc-NTSR1 axis and associates with tumor innervation features

Abstract

Cancer stem cells (CSCs) drive intra-tumor heterogeneity, therapy resistance, and relapse. Chemokines regulate cancer stemness via intercellular signaling within the tumor microenvironment. However, the role and clinical relevance of CCR3 in tumor subpopulations remain unexplored. In this study, we enriched CSCs by serum-free spheroid culture as spheroid-derived CSCs (SDCSCs). Cell proliferation, clonogenicity, migration/invasion, tumorsphere formation, chemo-drug resistance, in vivo tumorigenicity, signaling activity, and transcriptomic landscape were characterized. TCGA databases were analyzed for clinical relevance. We found that CCR3 silencing increased self-renewal capability, stemness markers expression, chemoresistance, and in vivo tumorigenicity in SDCSCs; however, it inhibited proliferation, colony formation, and invasion in parental cancer cells. Transcriptomic analysis revealed that CCR3 silencing induced pro-tumoral features in SDCSCs, while it resulted in anti-proliferative and anti-invasive profiles in parental cancer cells by oppositely regulating oncogenic signaling, including c-Myc, KRAS, mTORC, and HIF pathways. In SDCSCs, CCR3 silencing induced c-Myc nuclear expression and transcriptional activation, leading to NTSR1 upregulation and enhanced cancer stemness, which was hindered by a c-Myc inhibitor (10058-F4). Clinically, tumors with low CCR3 expression exhibited a transcriptomic landscape with enhanced cell growth and suppressed immune surveillance, accompanied by activated stemness-related signalings and tumor innervation signatures. High NTSR1 expression further exacerbated the poorer survival in patients with low CCR3 expression. In summary, CCR3 inhibition elicits divergent functional and transcriptomic responses in tumor subpopulations and is associated with stemness- and innervation-related signatures that predict poor prognosis. Combined targeting of CCR3 and the c-Myc-NTSR1 axis may eliminate CSCs.