Bugia Luis, Affolter Annette, Kern Johann, Sohn Emma, Jungbauer Frederic, Fleckenstein Jens, Lammert Anne, Rotter Nicole, Scherl Claudia
Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital Mannheim, Medical Faculty Mannheim of Heidelberg University, D‑68167 Mannheim, Germany.
Department of Radiation Oncology, University Hospital Mannheim, Medical Faculty Mannheim of Heidelberg University, D‑68167 Mannheim, Germany.
Oncol Rep. 2025 Nov;54(5). doi: 10.3892/or.2025.8984. Epub 2025 Sep 12.
Fractionated irradiation causes premature senescence of tumor cells. Interactions between senescence, the immune system and survival signaling are poorly understood to date. As MAP kinases are implicated in immune resistance, the present study addressed the detection of senescence‑associated modulation of postradiogenic programmed death‑ligand 1 (PD‑L1) and MAP kinase ERK1/2 expression in an and model for head and neck squamous cell carcinoma (HNSCC). Established HNSCC cell lines (UM-SCC-11B, UM-SCC-14C and UM-SCC-22B) were employed to study the expression levels of p21, histone H2AX (γH2AX), PD-L1 and phosphorylated (p)ERK1/2 via immunohistochemistry following application of 4x2 Gy. Using senescence‑associated β‑galactosidase (SA‑ß‑Gal) staining, postradiogenic induction of senescence was additionally assessed. Results were validated in a 3D HNSCC model with vital explants. Upon ionizing radiation (IR), senescence‑like subpopulations were observed in all cell lines, showing upregulation of PD‑L1 and pERK1/2 as well as of established senescence markers p21 and γH2AX. SA‑β‑Gal‑positive cells were found in all lines. These results were supported in a 3D tumor model. Fractionated IR can generate a subpopulation of HNSCC cells characterized by senescence‑typical cellular changes and marked expression of PD‑L1 and pERK1/2. Postradiogenic senescence in both 2D and 3D cancer models was possibly related to survival signaling and immune checkpoint regulation, crucial elements in tumor development and progress.
分次照射会导致肿瘤细胞过早衰老。迄今为止，衰老、免疫系统和生存信号之间的相互作用仍知之甚少。由于丝裂原活化蛋白激酶（MAP激酶）与免疫抵抗有关，本研究在头颈部鳞状细胞癌（HNSCC）的二维和三维模型中，探讨了放射后程序性死亡配体1（PD-L1）的衰老相关调节以及MAP激酶ERK1/2表达的检测。使用已建立的HNSCC细胞系（UM-SCC-11B、UM-SCC-14C和UM-SCC-22B），在给予4×2 Gy照射后，通过免疫组织化学研究p21、组蛋白H2AX（γH2AX）、PD-L1和磷酸化（p）ERK1/2的表达水平。此外，使用衰老相关β-半乳糖苷酶（SA-β-Gal）染色评估放射后衰老的诱导情况。结果在具有活性外植体的三维HNSCC模型中得到验证。在电离辐射（IR）后，在所有细胞系中均观察到衰老样亚群，其PD-L1、pERK1/2以及已确定的衰老标志物p21和γH2AX均上调。在所有细胞系中均发现了SA-β-Gal阳性细胞。这些结果在三维肿瘤模型中得到了支持。分次IR可产生一群HNSCC细胞亚群，其特征为具有衰老典型的细胞变化以及PD-L1和pERK1/2的显著表达。二维和三维癌症模型中的放射后衰老可能与生存信号和免疫检查点调节有关，这是肿瘤发生和进展的关键因素。
