Department of Spine Surgery and Musculoskeletal Tumor, Zhongnan Hospital of Wuhan University, Wuhan, China; Department of Plastic Surgery, Zhongnan Hospital of Wuhan University, Wuhan, China.
Department of Urology, Zhongnan Hospital of Wuhan University, Wuhan, China.
Biochem Pharmacol. 2023 Jun;212:115554. doi: 10.1016/j.bcp.2023.115554. Epub 2023 Apr 18.
Melanoma has become more common, and its therapeutic management has remained challenging in recent decades. The purpose of our study is to explore new prognostic therapeutic markers of melanoma and to find new therapeutic methods and therapeutic targets of novel drugs, which have great significance.
First, the arachidonate 5-lipoxygenase (ALOX5) gene associated with both autophagy and ferroptosis was identified by R version 4.2.0. We used human melanoma and para-cancer tissues, human melanoma cell lines, and melanoma-bearing mouse tissues. We used qRT-PCR, Western blotting, immunohistochemistry, immunofluorescence staining, CCK-8, iron ion assay, GSH assay, and MDA assay. In vivo, the ferroptosis activation and antitumor effects of recombinant human ALOX5 protein were evaluated using a xenograft model.
We report that the downregulation of ALOX5 in melanoma is positively correlated with the prognosis of patients and is an independent prognostic factor. Elevated ALOX5 contributes to autophagy and ferroptosis in vitro and in vivo. At the same time, inhibition of autophagy can reduce ferroptosis enhanced by ALOX5, and autophagy and ALOX5 have a synergistic effect. The results of the mechanistic study showed that the increase in ALOX5 could activate the AMPK/mTOR pathway and inhibit GPX4 expression, promoting the occurrence of autophagy-dependent ferroptosis, while the decrease in p-AMPK/AMPK inhibited the occurrence of ferroptosis.
ALOX5 deficiency was resistant to autophagy and ferroptosis by inhibiting the AMPK/mTOR pathway. Therefore, it can provide new targets and methods for melanoma drug development.
黑色素瘤变得更为常见，且在近几十年来其治疗管理仍具挑战性。我们研究的目的是探索黑色素瘤新的预后治疗标志物，寻找新的治疗方法和新型药物的治疗靶点，这具有重大意义。
首先，我们通过 R 版本 4.2.0 鉴定了与自噬和铁死亡均相关的花生四烯酸 5-脂氧合酶（ALOX5）基因。我们使用人黑色素瘤和癌旁组织、人黑色素瘤细胞系和携带黑色素瘤的小鼠组织。我们使用 qRT-PCR、Western blot、免疫组织化学、免疫荧光染色、CCK-8、铁离子测定、GSH 测定和 MDA 测定。在体内，使用异种移植模型评估重组人 ALOX5 蛋白的铁死亡激活和抗肿瘤作用。
我们报告，黑色素瘤中 ALOX5 的下调与患者的预后呈正相关，是独立的预后因素。ALOX5 升高有助于体外和体内的自噬和铁死亡。同时，抑制自噬可以减少 ALOX5 增强的铁死亡，并且自噬和 ALOX5 具有协同作用。机制研究的结果表明，ALOX5 的增加可以激活 AMPK/mTOR 通路并抑制 GPX4 表达，促进自噬依赖性铁死亡的发生，而 p-AMPK/AMPK 的减少则抑制铁死亡的发生。
ALOX5 缺乏通过抑制 AMPK/mTOR 通路抵抗自噬和铁死亡。因此，它可为黑色素瘤药物开发提供新的靶点和方法。
