Upstream stimulatory factor 2 inhibits erastin-induced ferroptosis in pancreatic cancer through transcriptional regulation of pyruvate kinase M2
Upstream stimulatory factor 2 inhibits erastin-induced ferroptosis in pancreatic cancer through transcriptional regulation of pyruvate kinase M2
复制标题
DOI：
10.1016/j.bcp.2022.115255
复制
发表时间：
2022-10-01
影响因子：
5.8
通讯作者：
Li, Yaming
中科院分区：
文献类型：
--
作者：
Chen, Meijie;Li, Xuena;Li, Yaming
铁凋亡被认为是化疗和放疗等肿瘤治疗的潜在靶点，但其对胰腺癌的调控机制尚不完全清楚。在此，我们探讨了上游刺激因子2（USF 2）和丙酮酸激酶M2（PKM 2）在PC细胞铁凋亡中的作用。USF 2和PKM 2在PC组织中呈高表达，USF 2与PKM 2呈正相关。用针对USF 2/PKM 2或USF 2过表达质粒的小干扰RNA转染PC细胞系BxpC-3和AsPC-1，或用针对PKM 2和USF 2过表达质粒的小干扰RNA共转染PC细胞系BxpC-3和AsPC-1。细胞转染后24小时，通过与20 μ mol/l erastin孵育24小时诱导铁凋亡细胞死亡。USF 2基因敲低促进了促铁凋亡细胞的死亡，而过表达抑制了促铁凋亡细胞的死亡。USF 2基因敲低可增加脂质活性氧和丙二醛的生成，降低谷胱甘肽浓度和谷胱甘肽过氧化物酶4的表达，表明脂质过氧化作用增强。USF 2敲除还增加亚铁水平和铁蛋白重链表达，并减少溶质载体家族7成员11的表达。然而，USF 2过表达逆转了这些变化。此外，双荧光素酶报告基因分析、染色质免疫沉淀分析和DNA pull down分析证实USF 2通过与其启动子结合来转录调控PKM 2的表达。有趣的是，PKM 2也负调节铁凋亡和PKM 2敲低显着削弱USF 2对脂质过氧化和铁凋亡细胞死亡的影响。本研究证明USF 2通过PKM 2的转录调控负调控PC细胞的铁凋亡，为揭示PC细胞铁凋亡的调控机制提供了新的证据。
Ferroptosis is considered as a potential target in cancer treatment including chemotherapy and radiotherapy, however, its regulatory mechanism on pancreatic cancer (PC) is not fully understood. Herein, we explored the role of upstream stimulatory factor 2 (USF2) and pyruvate kinase M2 (PKM2) in ferroptosis in PC cells. USF2 and PKM2 were highly expressed in PC tissues and USF2 was positively correlated with PKM2. PC cell lines BxpC-3 and AsPC-1 were transfected with small interfering RNAs against USF2/PKM2 or USF2 overexpressing plasmids or co-transfected with small interfering RNAs against PKM2 and USF2 overexpressing plasmids. Twenty-four hours after cell transfection, ferroptotic cell death was induced by incubation with 20 mu mol/l erastin for 24 h. Ferroptotic cell death was promoted by USF2 knockdown and inhibited by USF2 overexpression. USF2 knock-down increased lipid reactive oxygen species and malonaldehyde generation and decreased glutathione con-centration and glutathione peroxidase 4 expressions, indicating the enhanced lipid peroxidation. USF2 knockdown also increased ferrous iron levels and ferritin heavy chain expressions and reduced solute carrier family 7 member 11 expressions. However, USF2 overexpression reversed these changes. Furthermore, dual-luciferase reporter assay, chromatin immunoprecipitation assay and DNA pull down assay validated that USF2 transcriptionally regulated PKM2 expression through binding to its promoter. Interestingly, PKM2 also nega-tively regulated ferroptosis and PKM2 knockdown markedly impaired the effects of USF2 on lipid peroxidation and ferroptotic cell death. This study demonstrated that USF2 negatively regulated ferroptosis in PC cells through transcriptional regulation of PKM2, providing new evidences for uncovering the regulatory mechanism of fer-roptosis on PC.