Nrf2 inhibition reverses resistance to GPX4 inhibitor-induced ferroptosis in head and neck cancer
Nrf2 inhibition reverses resistance to GPX4 inhibitor-induced ferroptosis in head and neck cancer
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DOI：
10.1016/j.freeradbiomed.2018.10.426
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发表时间：
2018-12-01
影响因子：
7.4
通讯作者：
Roh, Jong-Lyel
中科院分区：
文献类型：
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作者：
Shin, Daiha;Kim, Eun Hye;Roh, Jong-Lyel
谷胱甘肽过氧化物酶4（GPX 4）是铁凋亡（铁依赖性，非凋亡性细胞死亡）的调节剂;其抑制可使治疗抗性癌细胞对铁凋亡敏感。然而，一些癌细胞产生了保护性机制来对抗铁凋亡;理解这些机制有助于克服化学抗性。在这项研究中，我们研究了头颈癌（HNC）中GPX 4抑制诱导的铁凋亡抵抗的分子机制。在HNC细胞系（包括顺铂抗性（HN 3R）和获得性RSL 3抗性（HN 3-rslR）细胞）中测试了两种GPX 4抑制剂（1 S，3R）-RSL 3和ML-162以及胡芦巴碱的作用。通过细胞活力、细胞死亡、脂质ROS产生和蛋白质表达以及小鼠肿瘤异种移植模型评估抑制剂和胡芦巴碱以及抑制p62、Keap 1或Nrf 2基因的作用。用RSL 3或ML-162处理可不同程度地诱导HNC细胞的铁凋亡。RSL 3或ML-162处理增加了化学抗性HN 3R和HN 3-rslR细胞中p62和Nrf 2的表达，灭活了Keap 1，并增加了磷酸-PERK-ATF 4-SESN 2途径的表达。Nrf 2的转录激活与对铁凋亡的抵抗相关。通过抑制Keap 1或Nrf 2基因转染使Nrf 2过表达使化学敏感的HN 3细胞对RSL 3具有抗性。然而，Nrf 2抑制或p62沉默使HN 3R细胞对RSL 3敏感。在移植有HN 3R的小鼠模型中，胡芦巴碱使化学抗性HNC细胞对RSL 3处理敏化。因此，Nrf 2-ARE途径的激活有助于HNC细胞对GPX 4抑制的抗性，并且抑制该途径逆转了HNC中对铁凋亡的抗性。
Glutathione peroxidase 4 (GPX4) is a regulator of ferroptosis (iron-dependent, non-apoptotic cell death); its inhibition can render therapy-resistant cancer cells susceptible to ferroptosis. However, some cancer cells develop mechanisms protective against ferroptosis; understanding these mechanisms could help overcome chemoresistance. In this study, we investigated the molecular mechanisms underlying resistance to ferroptosis induced by GPX4 inhibition in head and neck cancer (HNC). The effects of two GPX4 inhibitors, (1S, 3R)-RSL3 and ML-162, and of trigonelline were tested in HNC cell lines, including cisplatin-resistant (HN3R) and acquired RSL3-resistant (HN3-rslR) cells. The effects of the inhibitors and trigonelline, as well as of inhibition of the p62, Keap1, or Nrf2 genes, were assessed by cell viability, cell death, lipid ROS production, and protein expression, and in mouse tumor xenograft models. Treatment with RSL3 or ML-162 induced the ferroptosis of HNC cells to varying degrees. RSL3 or ML-162 treatment increased the expression of p62 and Nrf2 in chemoresistant HN3R and HN3-rslR cells, inactivated Keap1, and increased expression of the phospho-PERK-ATF4-SESN2 pathway. Transcriptional activation of Nrf2 was associated with resistance to ferroptosis. Overexpression of Nrf2 by inhibiting Keap1 or Nrf2 gene transfection rendered chemosensitive HN3 cells resistant to RSL3. However, Nrf2 inhibition or p62 silencing sensitized HN3R cells to RSL3. Trigonelline sensitized chemoresistant HNC cells to RSL3 treatment in a mouse model transplanted with HN3R. Thus, activation of the Nrf2-ARE pathway contributed to the resistance of HNC cells to GPX4 inhibition, and inhibition of this pathway reversed the resistance to ferroptosis in HNC.