1
|
Togashi K, Suzuki S, Mitobe Y, Nakagawa-Saito Y, Sugai A, Takenouchi S, Sugimoto M, Kitanaka C, Okada M. CEP-1347 Dually Targets MDM4 and PKC to Activate p53 and Inhibit the Growth of Uveal Melanoma Cells. Cancers (Basel) 2023; 16:118. [PMID: 38201546 PMCID: PMC10778035 DOI: 10.3390/cancers16010118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 12/11/2023] [Accepted: 12/22/2023] [Indexed: 01/12/2024] Open
Abstract
Uveal melanoma (UM) is among the most common primary intraocular neoplasms in adults, with limited therapeutic options for advanced/metastatic disease. Since UM is characterized by infrequent p53 mutation coupled with the overexpression of MDM4, a major negative regulator of p53, we aimed to investigate in this study the effects on UM cells of CEP-1347, a novel MDM4 inhibitor with a known safety profile in humans. We also examined the impact of CEP-1347 on the protein kinase C (PKC) pathway, known to play a pivotal role in UM cell growth. High-grade UM cell lines were used to analyze the effects of genetic and pharmacological inhibition of MDM4 and PKC, respectively, as well as those of CEP-1347 treatment, on p53 expression and cell viability. The results showed that, at its clinically relevant concentrations, CEP-1347 reduced not only MDM4 expression but also PKC activity, activated the p53 pathway, and effectively inhibited the growth of UM cells. Importantly, whereas inhibition of either MDM4 expression or PKC activity alone failed to efficiently activate p53 and inhibit cell growth, inhibition of both resulted in effective activation of p53 and inhibition of cell growth. These data suggest that there exists a hitherto unrecognized interaction between MDM4 and PKC to inactivate the p53-dependent growth control in UM cells. CEP-1347, which dually targets MDM4 and PKC, could therefore be a promising therapeutic candidate in the treatment of UM.
Collapse
Affiliation(s)
- Keita Togashi
- Department of Molecular Cancer Science, School of Medicine, Yamagata University, 2-2-2 Iida-nishi, Yamagata 990-9585, Japan
- Department of Ophthalmology and Visual Sciences, School of Medicine, Yamagata University, 2-2-2 Iida-nishi, Yamagata 990-9585, Japan
| | - Shuhei Suzuki
- Department of Molecular Cancer Science, School of Medicine, Yamagata University, 2-2-2 Iida-nishi, Yamagata 990-9585, Japan
- Department of Clinical Oncology, School of Medicine, Yamagata University, 2-2-2 Iida-nishi, Yamagata 990-9585, Japan
| | - Yuta Mitobe
- Department of Molecular Cancer Science, School of Medicine, Yamagata University, 2-2-2 Iida-nishi, Yamagata 990-9585, Japan
- Department of Neurosurgery, School of Medicine, Yamagata University, 2-2-2 Iida-nishi, Yamagata 990-9585, Japan
| | - Yurika Nakagawa-Saito
- Department of Molecular Cancer Science, School of Medicine, Yamagata University, 2-2-2 Iida-nishi, Yamagata 990-9585, Japan
| | - Asuka Sugai
- Department of Molecular Cancer Science, School of Medicine, Yamagata University, 2-2-2 Iida-nishi, Yamagata 990-9585, Japan
| | - Senri Takenouchi
- Department of Molecular Cancer Science, School of Medicine, Yamagata University, 2-2-2 Iida-nishi, Yamagata 990-9585, Japan
| | - Masahiko Sugimoto
- Department of Ophthalmology and Visual Sciences, School of Medicine, Yamagata University, 2-2-2 Iida-nishi, Yamagata 990-9585, Japan
- Research Institute for Promotion of Medical Sciences, Faculty of Medicine, Yamagata University, 2-2-2 Iida-nishi, Yamagata 990-9585, Japan
| | - Chifumi Kitanaka
- Department of Molecular Cancer Science, School of Medicine, Yamagata University, 2-2-2 Iida-nishi, Yamagata 990-9585, Japan
- Research Institute for Promotion of Medical Sciences, Faculty of Medicine, Yamagata University, 2-2-2 Iida-nishi, Yamagata 990-9585, Japan
| | - Masashi Okada
- Department of Molecular Cancer Science, School of Medicine, Yamagata University, 2-2-2 Iida-nishi, Yamagata 990-9585, Japan
| |
Collapse
|
2
|
Mitobe Y, Suzuki S, Nakagawa-Saito Y, Togashi K, Sugai A, Sonoda Y, Kitanaka C, Okada M. Antagonizing MDM2 Overexpression Induced by MDM4 Inhibitor CEP-1347 Effectively Reactivates Wild-Type p53 in Malignant Brain Tumor Cells. Cancers (Basel) 2023; 15:4326. [PMID: 37686602 PMCID: PMC10486490 DOI: 10.3390/cancers15174326] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 08/14/2023] [Accepted: 08/28/2023] [Indexed: 09/10/2023] Open
Abstract
The development of MDM4 inhibitors as an approach to reactivating p53 in human cancer is attracting increasing attention; however, whether they affect the function of MDM2 and how they interact with MDM2 inhibitors remain unknown. We addressed this question in the present study using CEP-1347, an inhibitor of MDM4 protein expression. The effects of CEP-1347, the genetic and/or pharmacological inhibition of MDM2, and their combination on the p53 pathway in malignant brain tumor cell lines expressing wild-type p53 were investigated by RT-PCR and Western blot analyses. The growth inhibitory effects of CEP-1347 alone or in combination with MDM2 on inhibition were examined by dye exclusion and/or colony formation assays. The treatment of malignant brain tumor cell lines with CEP-1347 markedly increased MDM2 protein expression, while blocking CEP-1347-induced MDM2 overexpression by genetic knockdown augmented the effects of CEP-1347 on the p53 pathway and cell growth. Blocking the MDM2-p53 interaction using the small molecule MDM2 inhibitor RG7112, but not MDM2 knockdown, reduced MDM4 expression. Consequently, RG7112 effectively cooperated with CEP-1347 to reduce MDM4 expression, activate the p53 pathway, and inhibit cell growth. The present results suggest the combination of CEP-1347-induced MDM2 overexpression with the selective inhibition of MDM2's interaction with p53, while preserving its ability to inhibit MDM4 expression, as a novel and rational strategy to effectively reactivate p53 in wild-type p53 cancer cells.
Collapse
Affiliation(s)
- Yuta Mitobe
- Department of Molecular Cancer Science, School of Medicine, Yamagata University, 2-2-2 Iida-nishi, Yamagata 990-9585, Japan
- Department of Neurosurgery, School of Medicine, Yamagata University, 2-2-2 Iida-nishi, Yamagata 990-9585, Japan
| | - Shuhei Suzuki
- Department of Molecular Cancer Science, School of Medicine, Yamagata University, 2-2-2 Iida-nishi, Yamagata 990-9585, Japan
- Department of Clinical Oncology, School of Medicine, Yamagata University, 2-2-2 Iida-nishi, Yamagata 990-9585, Japan
| | - Yurika Nakagawa-Saito
- Department of Molecular Cancer Science, School of Medicine, Yamagata University, 2-2-2 Iida-nishi, Yamagata 990-9585, Japan
| | - Keita Togashi
- Department of Molecular Cancer Science, School of Medicine, Yamagata University, 2-2-2 Iida-nishi, Yamagata 990-9585, Japan
- Department of Ophthalmology and Visual Sciences, School of Medicine, Yamagata University, 2-2-2 Iida-nishi, Yamagata 990-9585, Japan
| | - Asuka Sugai
- Department of Molecular Cancer Science, School of Medicine, Yamagata University, 2-2-2 Iida-nishi, Yamagata 990-9585, Japan
| | - Yukihiko Sonoda
- Department of Neurosurgery, School of Medicine, Yamagata University, 2-2-2 Iida-nishi, Yamagata 990-9585, Japan
| | - Chifumi Kitanaka
- Department of Molecular Cancer Science, School of Medicine, Yamagata University, 2-2-2 Iida-nishi, Yamagata 990-9585, Japan
- Research Institute for Promotion of Medical Sciences, Faculty of Medicine, Yamagata University, 2-2-2 Iida-nishi, Yamagata 990-9585, Japan
| | - Masashi Okada
- Department of Molecular Cancer Science, School of Medicine, Yamagata University, 2-2-2 Iida-nishi, Yamagata 990-9585, Japan
| |
Collapse
|