Proteomics Centre, Institute of Biochemistry, Vilnius University Life Sciences Centre, LT‑10257 Vilnius, Lithuania.
Int J Mol Med. 2022 Jun;49(6). doi: 10.3892/ijmm.2022.5140. Epub 2022 May 6.
Pancreatic cancer is a highly metastatic and therapy‑resistant disease. In the present study, the prospects of a novel approach to kill pancreatic cancer cells were examined: Starvation combined with ferroptosis induction. Established pancreatic cancer cell lines (Miapaca2, Panc‑1, Su.86.86 and T3M4), as well as a unique cell line, Capan‑26, which was originally derived in the authors' laboratory, were used. Cells were deprived from growth factors, amino acids and pseudo‑starved using treatment with mTOR inhibitors; erastin was used to induce ferroptosis. Cell viability and lipid peroxidation measurements using flow cytometry revealed that the starved pancreatic cancer cells reacted differently to ferroptosis induction: The Panc‑1, Su.86.86 and T3M4 cells gained sensitivity, while the Miapaca2 cells acquired resistance. Fluorescence microscopy revealed that ERK1/2 translocated to the nucleus of the starved pancreatic cancer cells. Moreover, ERK1/2 pharmacological inhibition with SCH772984 prevented erastin‑induced ferroptosis in the starved Panc‑1, Su.86.86 and T3M4 cells. Confocal microscopy also indicated JNK activation. However, the inhibition of this kinase revealed its unexpected role in oxidative stress management: Treatment with the JNK inhibitor, SP600125, increased the viability of pseudo‑starved cells following erastin treatment. In addition, the FBS‑starved Miapaca2 and Capan‑26 cells transitioned between epithelial and mesenchymal cell states. The results were further confirmed using wound healing assays, western blot analysis and microscopic analysis of epithelial‑to‑mesenchymal transition (EMT) markers. Mesenchymal properties were associated with a higher sensitivity to erastin, whereas epithelial‑like cells were more resistant. Finally, it was demonstrated that compounds targeting EMT‑related signaling pathways increased cell sensitivity to erastin. On the whole, these results confirm that in starved pancreatic cancer cells, ERK1/2 and JNK signaling, as well as switching between epithelial and mesenchymal states mediates sensitivity to erastin and reveal novel therapeutic prospects of the combination of starvation with ferroptosis induction.
胰腺癌是一种高度转移性和治疗耐药性疾病。在本研究中,研究了一种杀死胰腺癌细胞的新方法的前景:饥饿联合铁死亡诱导。使用已建立的胰腺癌细胞系(Miapaca2、Panc-1、Su.86.86 和 T3M4)以及作者实验室最初衍生的独特细胞系 Capan-26 进行研究。用 mTOR 抑制剂剥夺细胞生长因子、氨基酸和假性饥饿;用 erastin 诱导铁死亡。使用流式细胞术测量细胞活力和脂质过氧化,结果显示饥饿的胰腺癌细胞对铁死亡诱导的反应不同:Panc-1、Su.86.86 和 T3M4 细胞获得了敏感性,而 Miapaca2 细胞获得了耐药性。荧光显微镜显示 ERK1/2 易位到饥饿的胰腺癌细胞的核内。此外,用 SCH772984 抑制 ERK1/2 可防止饥饿的 Panc-1、Su.86.86 和 T3M4 细胞中 erastin 诱导的铁死亡。共聚焦显微镜还表明 JNK 激活。然而,抑制这种激酶揭示了其在氧化应激管理中的意外作用:用 JNK 抑制剂 SP600125 处理后,在用 erastin 处理假性饥饿细胞时,细胞活力增加。此外,FBS 饥饿的 Miapaca2 和 Capan-26 细胞在上皮细胞和间充质细胞状态之间转换。使用划痕愈合测定、western blot 分析和上皮-间质转化 (EMT) 标志物的显微镜分析进一步证实了这一点。间充质特性与对 erastin 的更高敏感性相关,而上皮样细胞则更具耐药性。最后,证明靶向 EMT 相关信号通路的化合物可提高细胞对 erastin 的敏感性。总的来说,这些结果证实,在饥饿的胰腺癌细胞中,ERK1/2 和 JNK 信号以及上皮细胞和间充质细胞状态之间的转换调节对 erastin 的敏感性,并揭示了饥饿与铁死亡诱导联合治疗的新前景。