PDF(Pubmed)
Abstract：
Senescent cells are known to secrete proteins, including inflammatory cytokines and damage‑associated molecular patterns. This phenomenon is known as the senescence‑associated secretory phenotype (SASP). SASP in cancer stromal fibroblasts is involved in cancer growth and progression. Conversely, metformin, an antidiabetic drug, has been reported to inhibit SASP induction by inhibiting the activation of NF‑κB, a regulator of SASP. To date, at least to the best of our knowledge, there have been no reports regarding cellular senescence in fibroblasts and tumor progression via the SASP‑mediated paracrine pathway. The present study thus aimed to elucidate the induction mechanisms of SASP in radiation‑induced fibroblasts and to determine its effects on cancer progression via the paracrine pathway. Furthermore, the present study aimed to determine whether controlling SASP using metformin suppresses cancer progression. A well‑differentiated esophageal cancer cell line established by the authors\' department and fibroblasts isolated and cultured from the non‑cancerous esophageal mucosa of resected esophageal cancer cases were used for the experiments. Fibroblasts were irradiated with 8 Gy radiation, and the changes in the expression of the senescence markers, SA‑β‑gal, p21, p16 and NF‑κB were evaluated using immunofluorescent staining and western blot analysis in the presence or absence of metformin treatment. The culture supernatants of irradiated fibroblasts treated with metformin and those treated without metformin were collected and added to the cancer cells to evaluate their proliferative, invasive and migratory abilities. Vimentin and E‑cadherin expression levels were also evaluated using immunofluorescent staining and western blot analysis. The expression levels of p16, p21 and NF‑κB in irradiated fibroblasts were attenuated by treatment with metformin. Supernatants collected from irradiated fibroblasts exhibited the proliferative activity of esophageal cancer cells, and the promotion of migratory and invasion abilities, which may be due to epithelial‑mesenchymal transition and changes in cell morphology. These reactions were confirmed to be suppressed by the addition of the supernatant of cultured fibroblasts pre‑treated with metformin. On the whole, the present study demonstrates that fibroblasts in the cancer stroma may be involved in tumor progression through cellular senescence.
摘要：
已知衰老细胞分泌蛋白质,包括炎性细胞因子和损伤相关的分子模式。这种现象被称为衰老相关分泌表型（SASP）。癌症基质成纤维细胞中的SASP参与癌症的生长和进展。相反，二甲双胍,一种抗糖尿病药物，据报道，通过抑制NF‑κB的激活来抑制SASP诱导，SASP的监管机构。迄今为止,至少就我们所知,没有关于成纤维细胞衰老和通过SASP介导的旁分泌途径进行肿瘤进展的报道。因此，本研究旨在阐明SASP在辐射诱导的成纤维细胞中的诱导机制，并确定其通过旁分泌途径对癌症进展的影响。此外，本研究旨在确定使用二甲双胍控制SASP是否能抑制癌症进展.作者部门建立的高分化食管癌细胞系和从切除的食管癌病例的非癌食管粘膜中分离和培养的成纤维细胞用于实验。成纤维细胞用8Gy辐射照射,以及衰老标记表达的变化，SA‑β‑gal，在存在或不存在二甲双胍治疗的情况下，使用免疫荧光染色和蛋白质印迹分析评估p21，p16和NF‑κB。收集用二甲双胍处理和不用二甲双胍处理的照射的成纤维细胞的培养上清液，并将其添加到癌细胞中以评估其增殖。侵入和迁移能力。波形蛋白和E-cadherin的表达水平也使用免疫荧光染色和蛋白质印迹分析进行评估。二甲双胍治疗可降低照射的成纤维细胞中p16，p21和NF‑κB的表达水平。从照射的成纤维细胞收集的上清液表现出食管癌细胞的增殖活性，以及提高迁徙和入侵能力，这可能是由于上皮间质转化和细胞形态的变化。通过添加用二甲双胍预处理的培养成纤维细胞的上清液，证实了这些反应被抑制。总的来说,本研究表明，癌间质中的成纤维细胞可能通过细胞衰老参与肿瘤的进展。
