Astaxanthin down-regulates Rad51 expression via inactivation of AKT kinase to enhance mitomycin C-induced cytotoxicity in human non-small cell lung cancer cells
Astaxanthin down-regulates Rad51 expression via inactivation of AKT kinase to enhance mitomycin C-induced cytotoxicity in human non-small cell lung cancer cells
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DOI：
10.1016/j.bcp.2016.02.016
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发表时间：
2016-04-01
影响因子：
5.8
通讯作者：
Lin, Yun-Wei
中科院分区：
文献类型：
--
作者：
Ko, Jen-Chung;Chen, Jyh-Cheng;Lin, Yun-Wei
虾青素已被证明具有广泛的有益作用，包括抗炎和抗癌特性。然而，虾青素诱导非小细胞肺癌(NSCLC)细胞毒性的分子机制尚未明确。RAD51在同源重组中发挥核心作用，研究表明，化疗耐药的癌症表现出高水平的RAD51表达。在本研究中，虾青素处理抑制了两种非小细胞肺癌细胞A549和H1703的细胞活力和增殖。虾青素处理(2.5-20 mU M)可降低RAD51表达和磷酸化AKT(Ser473)蛋白水平，并呈时间和剂量依赖性。此外，AKT(AKT-CA)载体的表达挽救了虾青素处理的NSCLC细胞中RAD51mRNA和蛋白水平的下降。联合应用磷脂酰肌醇3-激酶(PI3K)抑制剂(LY294002或Wortmannin)可进一步降低虾青素处理的A549和H1703细胞RAD51的表达。转染si-RAD51 RNA或与LY294002共同处理后，抑制RAD51的表达进一步增强虾青素的细胞毒作用和细胞生长抑制作用。此外，丝裂霉素C(MMC)作为一种抗肿瘤抗生素在非小细胞肺癌的临床化疗中得到了广泛的应用。MMC与虾青素联合应用对NSCLC细胞具有协同的细胞毒作用和细胞生长抑制作用，同时伴有磷酸化AKT(Ser473)水平和RAD51表达的降低。AKT-CA或FLAG标记的RAD51过表达可逆转虾青素和MMC诱导的协同细胞毒作用。相反，LY294002预处理进一步降低了虾青素和MMC共同处理的细胞的存活率。总之，虾青素通过减少RAD51的表达和AKT的激活来增强MMC诱导的细胞毒作用。这些发现可能为虾青素联合丝裂霉素治疗非小细胞肺癌提供理论依据。(C)2016 Elsevier Inc.保留所有权利。
Astaxanthin has been demonstrated to exhibit a wide range of beneficial effects, including anti-inflammatory and anti-cancer properties. However, the molecular mechanism of astaxanthin-induced cytotoxicity in non-small cell lung cancer (NSCLC) cells has not been identified. Rad51 plays a central role in homologous recombination, and studies show that chemo-resistant carcinomas exhibit high levels of Rad51 expression. In this study, astaxanthin treatment inhibited cell viability and proliferation of two NSCLC cells, A549 and H1703. Astaxanthin treatment (2.5-20 mu M) decreased Rad51 expression and phospho-AKT(Ser473) protein level in a time and dose-dependent manner. Furthermore, expression of constitutively active AKT (AKT-CA) vector rescued the decreased Rad51 mRNA and protein levels in astaxanthin-treated NSCLC cells. Combined treatment with phosphatidylinositol 3-kinase (PI3K) inhibitors (LY294002 or wortmannin) further decreased the Rad51 expression in astaxanthin-exposed A549 and H1703 cells. Knockdown of Rad51 expression by transfection with si-Rad51 RNA or cotreatment with LY294002 further enhanced the cytotoxicity and cell growth inhibition of astaxanthin. Additionally, mitomycin C (MMC) as an anti-tumor antibiotic is widely used in clinical NSCLC chemotherapy. Combination of MMC and astaxanthin synergistically resulted in cytotoxicity and cell growth inhibition in NSCLC cells, accompanied with reduced phospho-AKT(Ser473) level and Rad51 expression. Overexpression of AKT-CA or Flag-tagged Rad51 reversed the astaxanthin and MMC-induced synergistic cytotoxicity. In contrast, pretreatment with LY294002 further decreased the cell viability in astaxanthin and MMC co-treated cells. In conclusion, astaxanthin enhances MMC-induced cytotoxicity by decreasing Rad51 expression and AKT activation. These findings may provide rationale to combine astaxanthin with MMC for the treatment of NSCLC. (C) 2016 Elsevier Inc. All rights reserved.