At present, chemotherapy and radiotherapy represent the primary modalities of treatment for patients with unresectable esophageal squamous cell carcinoma (ESCC). However, the outcome of patients remains poor owing to radioresistance. The present study aimed to determine the radiosensitizing effect of liriodenine, an aporphine alkaloid derived from Enicosanthellum pulchrum, and investigating the underlying mechanisms in ESCC, using the esophageal cancer ECA-109 cell line. Cellular proliferation was evaluated using the Cell Counting kit-8 assay. Colony formation assay was performed to characterize the radiosensitive effects of liriodenine on ECA-109 cells, and flow cytometry was used to detect the percentage of cells undergoing apoptosis. An immunofluorescence assay was utilized to evaluate the DNA damage repair ability. Western blotting was used to assess the protein levels of caspase-3, B cell lymphoma-2 (Bcl-2) and Bcl-2-associated X (Bax). Liriodenine dose-dependently inhibited ECA-109 cell viability. The clonogenic survival assay demonstrated that liriodenine increased the radiosensitivity of ESCC cells, with a sensitization enhancement ratio of 1.11-1.69. The results of flow cytometry demonstrated that liriodenine induced apoptosis and G2/M arrest. The immunofluorescence assay revealed that liriodenine delays DNA damage repair. The upregulation of Bax and Caspase-3, and the suppression of Bcl-2 confirmed that apoptosis was occurring. Liriodenine radiosensitizes ECA-109 cells by inducing apoptosis and G2/M arrest. The findings of the present study indicated that liriodenine may represent an anticancer agent with promising potential for the treatment of ESCC.

中文翻译：

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Liriodenine通过诱导细胞凋亡和G2 / M阻滞来增强食道癌ECA-109细胞的放射敏感性。

目前，化学疗法和放射疗法代表了不可切除的食管鳞状细胞癌（ESCC）患者的主要治疗方式。但是，由于放射线抵抗，患者的结果仍然很差。本研究旨在确定食管癌ECA-109细胞系liriodenine的放射增敏作用，liriodenine是一种源自Enicosanthellum pulchrum的阿扑吗啡生物碱，并研究了ESCC的潜在机制。使用细胞计数试剂盒8测定法评估细胞增殖。进行集落形成测定以表征鹅绒素对ECA-109细胞的放射敏感性，并使用流式细胞术检测经历凋亡的细胞的百分比。免疫荧光测定法用于评估DNA损伤修复能力。Western印迹法用于评估caspase-3，B细胞淋巴瘤2（Bcl-2）和Bcl-2相关X（Bax）的蛋白水平。Liriodenine剂量依赖性抑制ECA-109细胞活力。无性系存活试验表明，鹅绒rio碱可增加ESCC细胞的放射敏感性，敏化增强比为1.11-1.69。流式细胞仪的结果表明，鹅绒被烯碱诱导了细胞凋亡和G2 / M阻滞。免疫荧光分析表明，鹅绒den碱可延缓DNA损伤修复。Bax和Caspase-3的上调以及Bcl-2的抑制证实发生了凋亡。Liriodenine通过诱导凋亡和G2 / M阻滞使ECA-109细胞放射增敏。本研究的发现表明，鹅绒素可能代表一种抗癌药物，有望用于治疗ESCC。