@article{20a0f530a7dd4699b34e747c2e69d6d4,
title = "Targeting PKLR/MYCN/ROMO1 signaling suppresses neuroendocrine differentiation of castration-resistant prostate cancer",
abstract = "Conventional treatment of prostate cancer (PCa) uses androgen-deprivation therapy (ADT) to inhibit androgen receptor (AR) signaling-driven tumor progression. ADT-induced PCa recurrence may progress to an AR-negative phenotype with neuroendocrine (NE) histologic features, which are associated with metabolic disturbances and poor prognoses. However, the metabolic pathways that regulate NE differentiation (NED) in PCa remain unclear. Herein, we show a regulatory mechanism in NED-associated metabolism dysfunction induced by ADT, whereby overexpression of pyruvate kinase L/R (PKLR) mediates oxidative stress through upregulation of reactive oxygen species modulator 1 (ROMO1), thereby promoting NED and aggressiveness. ADT mediates the nuclear translocation of PKLR, which binds to the MYCN/MAX complex to upregulate ROMO1 and NE-related genes, leading to altered mitochondrial function and NED of PCa. Targeting nuclear PKLR/MYCN using bromodomain and extra-terminal motif (BET) inhibitors has the potential to reduce PKLR/MYCN-driven NED. Abundant ROMO1 in serum samples may provide prognostic information in patients with ADT. Our results suggest that ADT resistance leads to upregulation of PKLR/MYCN/ROMO1 signaling, which may drive metabolic reprogramming and NED in PCa. We further show that increased abundance of serum ROMO1 may be associated with the development of NE-like PCa.",
keywords = "Androgen deprivation therapy (ADT), MYCN proto-oncogene (MYCN), Neuroendocrine prostate cancer (NEPC), Pyruvate kinase L/R (PKLR), Reactive oxygen species modulator 1 (ROMO1)",
author = "Chen, {Wei Yu} and {Thuy Dung}, {Phan Vu} and Yeh, {Hsiu Lien} and Chen, {Wei Hao} and Jiang, {Kuo Ching} and Li, {Han Ru} and Chen, {Zi Qing} and Michael Hsiao and Jiaoti Huang and Wen, {Yu Ching} and Liu, {Yen Nien}",
note = "Funding Information: Cancer cells have a high glycolytic and mitochondrial propensity to support nutrient depletion [11]. Alterations in mitochondrial (mt)DNA and the mitochondrial membrane potential (MMP) frequently occur in cancer cells, leading to altered mitochondrial function and reactive oxygen species (ROS) production [12]. ROS-mediated regulation of oncogenic signaling can cause oxidative damage, which further affects tumorigenesis and metastasis [13]. Increased ROS levels drive cells to enter a state of hyperproliferation accompanied by DNA damage, which further enhances drug resistance [13]. ROS were shown to activate resistance to multiple chemotherapeutic agents in various cancers, including PCa [14,15]. Dysregulation of AR signaling increases intracellular ROS levels [16]. Upregulation of ROS levels promotes the aggressive phenotype of PCa cells through increased ROS production and metabolic reprogramming [13]. The increase in metabolic reprogramming can support cell proliferation and lead to epigenetic changes, thereby promoting the development of NED subtypes of PCa [17]. However, the mechanism underlying ROS upregulation caused by ADT-induced metabolic enzymes that promotes mitochondrial biogenesis and which acts as a tumor promoter in the NED progression of PCa is currently unclear.Although ROMO1 was shown to be involved in regulating ROS production [32] and to be associated with the malignant progression of lung, bladder, and colorectal cancers [37–39], the functional role of ROMO1 in NED of PCa remains unknown. To determine the role of ROMO1 in affecting NED in AR-positive cells, ROMO1 cDNA was overexpressed in LNCaP cells. We found that ROMO1 overexpression in LNCaP cells increased NE markers associated with stem cell markers (Fig. 3A and B and Supplementary Fig. S3H), supporting NED in PCa being correlated with abundance of stem cell markers [40]. We also found that ROMO1 cDNA overexpression in LNCaP cells upregulated cell proliferation and 3D sphere formation (Fig. 3C and D), supporting the highly proliferative nature of NEPC cells [41]. To determine whether upregulation of ROMO1 mediates mitochondrial function, we examined the MMP in ROMO1-overexpressing LNCaP cells by staining with a mitochondrial stress indicator (DiOC2(3)) and flow cytometric measurements. Results showed that the MMP was upregulated upon ROMO1 overexpression, as indicated by DiOC2(3) accumulation (Fig. 3E). Moreover, higher mtDNA contents and ATP levels were found in ROMO1-overexpressing cells (Fig. 3F and G). In contrast, AR-negative PC3 cells with ROMO1-KD were found to have reduced NE and stem cell markers (Fig. 3H and I and Supplementary Fig. S3I). Reduced cell proliferation and 3D sphere formation as well as decreased mtDNA and cellular ATP contents were detected in PC3 cells with ROMO1-KD (Fig. 3J-M). A reduction in the MMP was observed in PC3 cells harboring ROMO1-KD (Fig. 3N). Importantly, ROMO1 overexpression in LNCaP cells resulted in upregulation of OCR values, whereas ROMO1-KD PC3 cells showed reduced OCR values, as determined with the Seahorse XF24 analyzer (Fig. 3O-P). These data suggest that ROMO1 overexpression may upregulate NED progression and change mitochondrial function in PCa.We thank Dr. Hsing-Jien Kung (Academician of Academia Sinica, Chair Professor of Taipei Medical University, Taiwan) for reading the manuscript and providing comments and helpful suggestions. We also thank Dr. Cheng-Wen Wu (Academician of Academia Sinica, Institute of Biomedical Sciences, Academia Sinica, Taiwan) and Dr. Shauh-Der Yeh (College of Medicine, Taipei Medical University, Taiwan) for their support and discussion on the experiments conducted in this study. This work was jointly supported by grants from the National Science and Technology Council, Taiwan (MOST109-2326-B-038-001-MY3 and MOST111-2628-B-038-016-MY3 to Y.N.L. and MOST111-2314-B-038-107-MY3 to Y.C.W.), National Health Research Institutes, Taiwan (NHRI-EX112-11109BI to Y.N.L.), and Wan Fang Hospital (111TMU-WFH-03 to W.Y.C.). This work was financially supported by the “TMU Research Center of Cancer Translational Medicine” from The Featured Areas Research Center Program within the framework of the Higher Education Sprout Project by the Ministry of Education (MOE) in Taiwan. Funding Information: We thank Dr. Hsing-Jien Kung (Academician of Academia Sinica, Chair Professor of Taipei Medical University, Taiwan) for reading the manuscript and providing comments and helpful suggestions. We also thank Dr. Cheng-Wen Wu (Academician of Academia Sinica, Institute of Biomedical Sciences, Academia Sinica, Taiwan) and Dr. Shauh-Der Yeh (College of Medicine, Taipei Medical University, Taiwan) for their support and discussion on the experiments conducted in this study. This work was jointly supported by grants from the National Science and Technology Council, Taiwan ( MOST109-2326-B-038-001-MY3 and MOST111-2628-B-038-016-MY3 to Y.N.L., and MOST111-2314-B-038-107-MY3 to Y.C.W.), National Health Research Institutes, Taiwan ( NHRI-EX112-11109B I to Y.N.L.), and Wan Fang Hospital ( 111TMU-WFH-03 to W.Y.C.). This work was financially supported by the “ TMU Research Center of Cancer Translational Medicine ” from The Featured Areas Research Center Program within the framework of the Higher Education Sprout Project by the Ministry of Education (MOE) in Taiwan . Publisher Copyright: {\textcopyright} 2023 The Author(s)",
year = "2023",
month = jun,
doi = "10.1016/j.redox.2023.102686",
language = "English",
volume = "62",
journal = "Redox Biology",
issn = "2213-2317",
publisher = "Elsevier B.V.",
}
