Alternatively activated macrophages in tumor microenvironment is defined as M2 tumor-associated macrophages (M2 TAMs) that promote cancer progression. However, communicative mechanisms between M2 TAMs and cancer cells in squamous cell carcinoma of head and neck (SCCHN) remain largely unknown. Quantitative real-time PCR, western blotting, enzyme-linked immunosorbent assay and flow cytometry were applied to quantify mRNA and protein expression of genes related to M2 TAMs, epithelial–mesenchymal transition (EMT) and stemness. Wounding-healing and Transwell invasion assays were performed to detect the invasion and migration. Sphere formation assay was used to detect the stemness of SCCHN cells. RNA-sequencing and following bioinformatics analysis were used to determine the alterations of transcriptome. THP-1 monocytes were successfully polarized into M2-like TAMs, which was manifested by increased mRNA and protein expression of CCL18, IL-10 and CD206. Conditioned medium from M2-like TAMs promoted the migration and invasion of SCCHN cells, which was accompanied by the occurrence of EMT and enhanced stemness. Importantly, CCL18 neutralizing antibody partially abrogated these effects that caused by conditional medium from M2-like TAMs. In addition, recombinant human CCL18 (rhCCL18) correspondingly promoted the malignant biological behaviors of SCCHN in vitro. Finally, RNA-sequencing analysis identified 331 up-regulated and 363 down-regulated genes stimulated by rhCCL18, which were statistically enriched in 10 cancer associated signaling pathways. These findings indicate that CCL18 derived from M2-like TAMs promotes metastasis via inducing EMT and cancer stemness in SCCHN in vitro.

PERP may have the potential to function as an oncogene. However, the precise function, prognostic value, and predictive significance remain shrouded in ambiguity. We conducted an in-depth analysis using pan-cancer RNA sequencing data and various online web tools to investigate the correlation between PERP and crucial clinical outcomes such as prognosis, tumor microenvironment, and tumor metabolism. In addition, we explored the tumor-promoting role of PERP and its potential mechanisms through models such as immunofluorescence staining, flow cytometry, cell proliferation assays, wound healing assays, cell migration assays, mass spectrometry analysis and isotope tracing. Further in vivo models confirmed the functional consistency of PERP across pan-cancer. Finally, we analyzed the potential of PERP as a predictive factor for immunotherapy sensitivity in a clinical cohort. PERP exhibits elevated expression in the majority of cancer types and impedes immune cell infiltration as well as immune checkpoint reactivity in pan-cancer. We confirmed that PERP can promote tumor progression by tumor cell proliferation, scratch and transwell experiments. Meanwhile, the absence of PERP restricts the flux of 13C6-glucose into glycolysis and the tricarboxylic acid (TCA) cycle. Importantly, the deficiency of PERP enhances the in vivo anti-tumor efficacy of PD1 monoclonal antibodies. In addition, low PERP expression is highly correlated with the response of head and neck squamous cell carcinoma (HNSCC) patients to immunotherapy. PERP represents a promising predictive/diagnostic biomarker and therapeutic target for HNSCC patients.

Hypopharyngeal squamous cell carcinoma (HPSCC), an aggressive head and neck cancer with dismal prognosis, faces persistent chemoresistance to standard TPF (docetaxel, cisplatin, 5-fluorouracil) regimen. However, the immunological mechanisms underlying chemoresistance remain undefined. Here, we perform longitudinal single-cell RNA sequencing (scRNA-seq) profiling of paired pre-/post-TPF HPSCC specimens, mapping immune cell dynamics underlying chemoresistance. Our study identifies ZNF683⁺ natural killer (NK) cells as a gatekeeper of chemotherapy efficacy through integrated single-cell transcriptomics, spatial multiplex immunohistochemistry and functional validation. Moreover, pretreatment baseline enrichment of ZNF683⁺ NK cells predicts TPF response, while GZMK⁺CD8⁺ effector memory T cells function as the predominant immunologic effector to successful TPF intervention. Mechanistically, bioinformatics and in vitro coculture data reveal that ZNF683⁺ NK cells directly interact with CD8⁺ T cells, and drive an MHC-I-dependent licensing of polyfunctional GZMK⁺CD8⁺ effector memory T cells. Collectively, this NK-CD8⁺ axis provides a potential predictive biomarker and therapeutic target to overcome chemoresistance in patients with HPSCC.