Department of Dermatology of The Third Affiliated Hospital, Xinxiang Medical University, Xinxiang, Henan 453003, PR China; School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, Henan 453003, PR China.
Department of Dermatology of The Third Affiliated Hospital, Xinxiang Medical University, Xinxiang, Henan 453003, PR China.
Biochem Pharmacol. 2023 Dec;218:115874. doi: 10.1016/j.bcp.2023.115874. Epub 2023 Oct 20.
Melanoma cells were more resistant to ferroptosis with still poor therapy outcomes. Sensitizing melanoma cell to the ferroptosis inducer was a crucial strategy for treatment of melanoma. In the present study, 2,2'-di-pyridylketone hydrazone dithiocarbamate s-butyric acid (DpdtbA) displayed superior inhibitory activity than ferroptosis inducer Erastin in melanoma cells, which prompt us to explore the underlying mechanism. The analyses from flow cytometry and Western blot showed that the growth inhibition of DpdtbA against SK-MEL-28 and A375 cells involved apoptosis induction and G1 phase arrest. Surprisingly, the cytoplasmic vacuoles were found upon the treatment; transmission electron microscopy and endoplasmic reticulum (ER) staining revealed that the cytoplasmic vacuoles were in ER; while down-regulation of alix and requirement of protein synthesis suggested there was an occurrence of paraptosis. However, both NAC and 3-MA could significantly attenuate the cytoplasmic vacuolization and growth inhibition, hinting that both ROS and autophagy involved the paraptosis induction. The additional evidence revealed that there was an occurrence of continuous ferritinophagy, which was responsible for the ROS production. Downregulation of NCOA4 clearly attenuated the apoptosis and paraptosis induction. In addition, activation of MAPK involved regulation of paraptosis, but only ERK and JNK had role in the formation of cytoplasmic vacuoles and growth inhibition. Furthermore, a ROS dependent regulation of PI3K/AKT pathway was also involved. Taken together, our result firstly demonstrated that a continuous ferritinophagy contributed to the apoptosis and paraptosis induction, highlighting that the lysosomal labile iron pool had a crucial role in control of melanoma cell fate.
黑色素瘤细胞对铁死亡的抵抗力更强，治疗效果仍然不佳。使黑色素瘤细胞对铁死亡诱导剂敏感是治疗黑色素瘤的关键策略。在本研究中，2,2'-二吡啶酮腙二硫代氨基甲酸盐 s-丁基（DpdtbA）在黑色素瘤细胞中显示出比铁死亡诱导剂 Erastin 更高的抑制活性，这促使我们探索其潜在机制。流式细胞术和 Western blot 分析表明，DpdtbA 对 SK-MEL-28 和 A375 细胞的生长抑制涉及凋亡诱导和 G1 期阻滞。令人惊讶的是，在治疗后发现细胞质空泡；透射电子显微镜和内质网（ER）染色显示细胞质空泡位于 ER 中；而 alix 的下调和蛋白质合成的需求表明发生了副凋亡。然而，NAC 和 3-MA 均可显著减轻细胞质空泡化和生长抑制，提示 ROS 和自噬均参与了副凋亡的诱导。进一步的证据表明，存在连续的铁蛋白自噬，这是 ROS 产生的原因。NCOA4 的下调明显减弱了凋亡和副凋亡的诱导。此外，MAPK 的激活涉及副凋亡的调节，但只有 ERK 和 JNK 参与细胞质空泡的形成和生长抑制。此外，ROS 依赖性的 PI3K/AKT 通路调节也参与其中。总之，我们的结果首次表明，连续的铁蛋白自噬有助于凋亡和副凋亡的诱导，突出了溶酶体不稳定铁池在控制黑色素瘤细胞命运中的关键作用。
