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Gudikote JP, Cascone T, Poteete A, Sitthideatphaiboon P, Wu Q, Morikawa N, Zhang F, Peng S, Tong P, Li L, Shen L, Nilsson M, Jones P, Sulman EP, Wang J, Bourdon JC, Johnson FM, Heymach JV. Inhibition of nonsense-mediated decay rescues p53β/γ isoform expression and activates the p53 pathway in MDM2-overexpressing and select p53-mutant cancers. J Biol Chem 2021; 297:101163. [PMID: 34481841 PMCID: PMC8569473 DOI: 10.1016/j.jbc.2021.101163] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 08/16/2021] [Accepted: 09/01/2021] [Indexed: 12/13/2022] Open
Abstract
Inactivation of p53 is present in almost every tumor, and hence, p53-reactivation strategies are an important aspect of cancer therapy. Common mechanisms for p53 loss in cancer include expression of p53-negative regulators such as MDM2, which mediate the degradation of wildtype p53 (p53α), and inactivating mutations in the TP53 gene. Currently, approaches to overcome p53 deficiency in these cancers are limited. Here, using non–small cell lung cancer and glioblastoma multiforme cell line models, we show that two alternatively spliced, functional truncated isoforms of p53 (p53β and p53γ, comprising exons 1 to 9β or 9γ, respectively) and that lack the C-terminal MDM2-binding domain have markedly reduced susceptibility to MDM2-mediated degradation but are highly susceptible to nonsense-mediated decay (NMD), a regulator of aberrant mRNA stability. In cancer cells harboring MDM2 overexpression or TP53 mutations downstream of exon 9, NMD inhibition markedly upregulates p53β and p53γ and restores activation of the p53 pathway. Consistent with p53 pathway activation, NMD inhibition induces tumor suppressive activities such as apoptosis, reduced cell viability, and enhanced tumor radiosensitivity, in a relatively p53-dependent manner. In addition, NMD inhibition also inhibits tumor growth in a MDM2-overexpressing xenograft tumor model. These results identify NMD inhibition as a novel therapeutic strategy for restoration of p53 function in p53-deficient tumors bearing MDM2 overexpression or p53 mutations downstream of exon 9, subgroups that comprise approximately 6% of all cancers.
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Affiliation(s)
- Jayanthi P Gudikote
- Department of Thoracic Head and Neck Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Tina Cascone
- Department of Thoracic Head and Neck Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Alissa Poteete
- Department of Thoracic Head and Neck Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Piyada Sitthideatphaiboon
- Department of Thoracic Head and Neck Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Qiuyu Wu
- Department of Melanoma Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Naoto Morikawa
- Department of Thoracic Head and Neck Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Fahao Zhang
- Department of Thoracic Head and Neck Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Shaohua Peng
- Department of Thoracic Head and Neck Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Pan Tong
- Department of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Lerong Li
- Department of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Li Shen
- Department of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Monique Nilsson
- Department of Thoracic Head and Neck Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Phillip Jones
- Institute for Applied Cancer Science, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Erik P Sulman
- Department of Radiation Oncology and Brain and Spine Tumor Center, Laura and Isaac Perlmutter Cancer Center, NYU Langone School of Medicine, New York, New York, USA
| | - Jing Wang
- Department of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA; The University of Texas MD Anderson Cancer Center Graduate School of Biomedical Sciences, Houston, Texas, USA
| | - Jean-Christophe Bourdon
- Cellular Division, Ninewells Hospital Campus, School of Medicine, University of Dundee, Dundee, UK
| | - Faye M Johnson
- Department of Thoracic Head and Neck Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA; The University of Texas MD Anderson Cancer Center Graduate School of Biomedical Sciences, Houston, Texas, USA
| | - John V Heymach
- Department of Thoracic Head and Neck Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA.
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