Poly(ethylene oxide)-poly(2-methoxyethyl acrylate) diblock copolymers (PEO-b-PMEA) are synthesized by RAFT aqueous dispersion polymerization of MEA using poly(ethylene oxide) macromolecular chain transfer agent as a reactive steric stabilizer. Both segments are well-known to be bio-and blood-compatible polymers. This formulation enables the production of various particle morphologies such as spheres, worms, and vesicles from the same block copolymer in water. The synthesis starts when both the reactive steric stabilizer and MEA monomer are dissolved in water; however, the growing polymer is not water-soluble and begins to form nano-objects. In the case of the synthesis of PEO 113-b-MEA 300 diblock copolymers, the nano-objects change from spheres into larger aggregates of worms when the solids concentration in the polymerization increases from 5 to 15 wt% at full monomer conversion. The morphology finally turns into vesicles as the solids concentration increases to 20 wt%. The final block copolymer morphology at full monomer conversion is dictated by not only degree of polymerization of MEA but also the solids concentration in the polymerization mixture.

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Tumor cells have evolved sophisticated means of escape from the host immune system. To date, several important immunological phenomena have been revealed in peripheral blood as well as within tumors. In the present study, we first investigated the proportion and activation status of peripheral immune regulatory cells and CD8+ T‐cell subsets in patients with head and neck squamous cell carcinoma (HNSCC) using a multicolor flow cytometer, and then evaluated how therapy with docetaxel, cisplatin, and 5‐fluorouracil modulated the immune cell profile in peripheral blood. The proportion of naïve T cells was lower and that of effector memory T cells (TEM) was higher in HNSCC patients than in healthy donors. Moreover, the proportions of activated TEM cells and effector T cells (TEFF) were dramatically increased in patients with advanced stage disease. The proportion of regulatory T cells and CD14+HLA‐DR− myeloid‐derived suppressor cells was elevated in HNSCC patients. Of note, after therapy, in addition to the transient reduction in immune regulatory cells, decreases in central memory T cells and increases in TEFF cells were observed among CD8+ T‐cell subsets, suggesting differentiation from central memory T cells into TEFF cells. Our results suggested that, despite the immunosuppressive status in HNSCC patients, tumor‐specific immune responses mediated by CD8+ T cells might be induced and maintained. Moreover, chemotherapy can trigger not only a transient reduction in immune regulatory cells but also further activation of CD8+ T cells.

Head and neck squamous carcinoma (HNSCC) is highly infiltrated by immune cells, including tumor-infiltrating lymphocytes and myeloid lineage cells. In the tumor microenvironment, tumor cells orchestrate a highly immunosuppressive microenvironment by secreting immunosuppressive mediators, expressing immune checkpoint ligands, and downregulating human leukocyte antigen expression. In the present study, we aimed to comprehensively profile the immune microenvironment of HNSCC using gene expression data obtained from public database. We calculated enrichment scores of 33 immune cell types based on gene expression data of HNSCC tissues and adjacent non-cancer tissues. Based on these scores, we performed non-supervised clustering and identified three immune signatures—cold, lymphocyte, and myeloid/dendritic cell (DC)—based on the clustering results. We then compared the clinical and biological features of the three signatures. Among HNSCC and non-cancer tissues, human papillomavirus (HPV)-positive HNSCCs exhibited the highest scores in various immune cell types, including CD4+ T cells, CD8+ T cells, B cells, plasma cells, basophils, and their subpopulations. Among the three immune signatures, the proportions of HPV-positive tumors, oropharyngeal cancers, early T tumors, and N factor positive cases were significantly higher in the lymphocyte signature than in other signatures. Among the three signatures, the lymphocyte signature showed the longest overall survival (OS), especially in HPV-positive patients, whereas the myeloid/DC signature demonstrated the shortest OS in these patients. Gene set enrichment analysis revealed the upregulation of several pathways related to inflammatory and proinflammatory responses in the lymphocyte signature. The expression of PRF1, IFNG, GZMB, CXCL9, CXCL10, PDCD1, LAG3, CTLA4, HAVCR2, and TIGIT was the highest in the lymphocyte signature. Meanwhile, the expression of PD-1 ligand genes CD274 and PDCD1LG2 was highest in the myeloid/DC signature. Herein, our findings revealed the transcriptomic landscape of the immune microenvironment that closely reflects the clinical and biological significance of HNSCC, indicating that molecular profiling of the immune microenvironment can be employed to develop novel biomarkers and precision immunotherapies for HNSCC.

This study aimed to evaluate the efficacy of carbon‐ion radiotherapy in combination with chemotherapy using dacarbazine, nimustine, and vincristine (DAV therapy) in mucosal melanoma. Twenty‐one patients with clinically localized mucosal melanoma of the head and neck were enrolled. The primary endpoint was 3‐year overall survival (OS). Secondary endpoints included local control, progression‐free survival (PFS), and adverse event occurrence. Carbon‐ion radiotherapy with a dose of 57.6‐64.0 Gy (relative biological effectiveness) in 16 fractions was delivered concurrently with DAV therapy, and 2 cycles of adjuvant DAV therapy were administered every 6 weeks. The median follow‐up periods were 15.5 months for all patients, and 31.2 months for 12 surviving patients. All patients had locally advanced T4a or T4b disease in the rhino‐sinus area. In 16 patients (76.2%), 3 cycles of planned DAV therapy were completed. The 3‐year OS and PFS rates were 49.2% and 37.0% respectively. The 3‐year local control rate was 92.3%. Eleven patients (52%) developed distant metastasis, which was the most frequent pattern of the first failure. Commonly presenting acute grade 2‐3 toxicities associated with radiotherapy and chemotherapy were mucositis (11 patients [53%]) and leukopenia (9 patients [43%]), which improved with conservative therapy. None of the patients developed grade 3 or greater late toxicities. Carbon‐ion radiotherapy in combination with DAV therapy led to excellent local control for advanced mucosal melanoma within acceptable toxicities. The efficacy of additional DAV therapy in improving survival was weaker than expected as distant metastases still occurred frequently. Trial registration no. UMIN000007939.