前列腺癌（PCa）是美国最常见的男性癌症。阿比特龙或恩扎鲁胺已被批准用于治疗转移性去势抵抗性前列腺癌（CRPC）。然而，治疗后产生的神经内分泌型前列腺癌（t-NEPC）可能会发展，导致约10-17%的CRPC患者出现耐药性。详细机制尚不清楚。通过分析公开可获得的数据集或在肿瘤标本中进行免疫组化染色来确定TOMM20和AR在PCa中的表达相关性。通过共免疫沉淀或GST拉下实验验证TOMM20和AR的蛋白相互作用。通过细胞增殖、侵袭、球体形成、异种移植生长和静脉转移实验阐明了TOMM20耗竭对药物敏感性的影响。通过流式细胞术测量细胞内ROS水平，并通过RNA-seq、RT-PCR和免疫印迹验证NEPC转分化和癌干细胞特性。TOMM20蛋白水平与PCa细胞和标本中的AR呈正相关。TOMM20蛋白与AR物理相互作用。AR拮抗剂通过自噬溶酶体途径诱导TOMM20蛋白降解，从而提高细胞内ROS水平并激活PI3K/AKT信号通路。当TOMM20被耗竭时，PCa细胞发生EMT，获得癌干细胞的特性，并对AR拮抗剂产生抗药性。稳定的TOMM20耗竭促进了PCa腺癌向NEPC转分化和转移。相反，恢复TOMM20使耐药性PCa细胞重新对AR拮抗剂产生敏感。AR拮抗剂诱导的TOMM20蛋白降解促进了PCa向NEPC的转分化，从而揭示了AR拮抗剂通过线粒体外膜介导的信号通路发展耐药性的新的分子机制。这些发现表明，在PCa组织中TOMM20表达的降低或丧失可能成为预测PCa对AR拮抗剂耐药性的一个有用的预测因子。©2023。意大利国家癌症研究所“Regina Elena”。

Prostate cancer(PCa) is the most commonly occurring male cancer in the USA. Abiraterone or Enzalutamide have been approved for the treatment of metastatic castration-resistant prostate cancer (CRPC). However, the treatment-emergent neuroendocrine PCa (t-NEPC) may develop, resulting in drug resistance in about 10-17% CRPC patients. The detailed mechanisms remain unclear..The expression correlation of TOMM20 and AR in PCa was determined by analyzing publicly available datasets, or by IHC staining in tumor specimens. The protein interaction of TOMM20 and AR was validated by co-immunoprecipitation or GST pull-down assay. The impact of TOMM20 depletion on drug sensitivity were elucidated by assays of cell proliferation, invasion, sphere formation, xenograft growth and intravenous metastasis. The intracellular ROS level was measured by flow cytometry, and the NEPC transdifferentiation and characteristics of cancer stem-like cells were validated by RNA-seq, RT-PCR and western blotting.The protein level of TOMM20 is positively correlated with AR in PCa cells and specimens. TOMM20 protein physically interacts with AR. AR antagonists induced the protein degradation of TOMM20 through autophagy-lysosomal pathway, thereby elevating the intracellular ROS level and activating PI3K/AKT signaling pathway. When TOMM20 was depleted, PCa cells underwent EMT, acquired the characteristics of cancer stem-like cells, and developed resistance to AR antagonists. The stable depletion of TOMM20 promoted the transdifferentiation of PCa adenocarcinoma into NEPC and metastasis. Conversely, the rescue of TOMM20 re-sensitized the resistant PCa cells to AR antagonists.TOMM20 protein degradation induced by AR antagonists promoted the transdifferentiation of PCa to NEPC, thereby revealing a novel molecular mechanism by which AR antagonists develop drug resistance through mitochondrial outer membrane-mediated signaling pathway. These findings suggested that the decreasing or loss of TOMM20 expression in PCa tissues might become a useful predictor of PCa resistance to AR antagonists.© 2023. Italian National Cancer Institute ‘Regina Elena’.