Abstract

Background

Radiotherapy is an effective treatment for esophageal squamous cell carcinoma (ESCC). However, many ESCC patients relapsed after receiving radiotherapy due to the inherent resistance. The function of miR-34a and SIRT1, as well as the correlation between miR-34a and SIRT1 has been widely claimed in multiple types of malignant tumors. This study aimed to investigate the effects of miR-34a on radiation resistance against ESCC and the underlying mechanism.

Methods

In this study, CCK8, flow cytometry, wounding healing assays, and cell clone formation assay were used to determine the in vitro anti-tumor effects of radiation on radiation-resistant ESCC cell line (rECA-109). The luciferase activity and Western Blot assays were used to investigate the relationship among miR-34a, SIRT1, and the anti-radiation resistant effects. The xenograft experiments were used to verify the important function of miR-34a and SIRT1 in radiation resistance against ESCC. The apoptosis state of tumor tissues was evaluated by TUNEL assay.

Results

The introduction of miR-34a significantly induced the cell death and apoptosis of rECA-109 and inhibit the migration of rECA-109 treated by radiation. The anti-tumor effect was accompanied by the downregulation of SIRT1 and the inhibition of PI3K/AKT/mTOR signal pathway. The radiation resistance on rECA-109 cells was reversed by silencing SIRT1, accompanied by the PI3K/AKT/mTOR signal pathway inhibited. In vivo experiments revealed that the radiation resistance on ESCC was reversed by the introduction of miR-34a, the effect of which was promoted by the activation of SIRT1.

Conclusion

Our results showed that miR-34a could reverse the radiation resistance on rECA-109 cells by downregulating the expression of SIRT1through inhibiting the PI3K-AKT-mTOR signal pathway.

中文翻译：

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MiR-34a通过下调SIRT1表达抑制PI3K/AKT/mTOR信号通路逆转ECA-109细胞的辐射抗性

摘要

背景

放射治疗是食管鳞状细胞癌（ESCC）的有效治疗方法。然而，许多 ESCC 患者在接受放疗后由于其固有的耐药性而复发。miR-34a 和 SIRT1 的功能以及 miR-34a 和 SIRT1 之间的相关性已在多种类型的恶性肿瘤中被广泛声称。本研究旨在探讨 miR-34a 对 ESCC 辐射抗性的影响及其潜在机制。

方法

在本研究中，CCK8、流式细胞术、伤口愈合试验和细胞克隆形成试验用于确定辐射对抗辐射 ESCC 细胞系 (rECA-109) 的体外抗肿瘤作用。荧光素酶活性和蛋白质印迹分析用于研究 miR-34a、SIRT1 和抗辐射效应之间的关系。异种移植实验用于验证 miR-34a 和 SIRT1 在抗 ESCC 辐射中的重要功能。TUNEL法检测肿瘤组织的凋亡状态。

结果

miR-34a的引入显着诱导了rECA-109的细胞死亡和凋亡，并抑制了辐射处理的rECA-109的迁移。抗肿瘤作用伴随着SIRT1的下调和PI3K/AKT/mTOR信号通路的抑制。rECA-109 细胞的辐射抗性通过沉默 SIRT1 逆转，同时抑制 PI3K/AKT/mTOR 信号通路。体内实验表明，miR-34a 的引入逆转了 ESCC 的辐射抗性，其作用是通过激活 SIRT1 来促进的。

结论

我们的结果表明，miR-34a 可以通过抑制 PI3K-AKT-mTOR 信号通路下调 SIRT1 的表达，从而逆转 rECA-109 细胞的辐射抗性。