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Li AX, Martin TA, Lane J, Jiang WG. Cellular Impacts of Striatins and the STRIPAK Complex and Their Roles in the Development and Metastasis in Clinical Cancers (Review). Cancers (Basel) 2023; 16:76. [PMID: 38201504 PMCID: PMC10777921 DOI: 10.3390/cancers16010076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 12/18/2023] [Accepted: 12/20/2023] [Indexed: 01/12/2024] Open
Abstract
Striatins (STRNs) are generally considered to be cytoplasmic proteins, with lower expression observed in the nucleus and at cell-cell contact regions. Together with protein phosphatase 2A (PP2A), STRNs form the core region of striatin-interacting phosphatase and kinase (STRIPAK) complexes through the coiled-coil region of STRN proteins, which is crucial for substrate recruitment. Over the past two decades, there has been an increasing amount of research into the biological and cellular functions of STRIPAK members. STRNs and the constituent members of the STRIPAK complex have been found to regulate several cellular functions, such as cell cycle control, cell growth, and motility. Dysregulation of these cellular events is associated with cancer development. Importantly, their roles in cancer cells and clinical cancers are becoming recognised, with several STRIPAK components found to have elevated expression in cancerous tissues compared to healthy tissues. These molecules exhibit significant diagnostic and prognostic value across different cancer types and in metastatic progression. The present review comprehensively summarises and discusses the current knowledge of STRNs and core STRIPAK members, in cancer malignancy, from both cellular and clinical perspectives.
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Affiliation(s)
| | - Tracey A. Martin
- Cardiff China Medical Research Collaborative, School of Medicine, Cardiff University, Cardiff CF14 4XN, UK; (A.X.L.); (J.L.); (W.G.J.)
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Cokelaere C, Dok R, Cortesi EE, Zhao P, Sablina A, Nuyts S, Derua R, Janssens V. TIPRL1 and its ATM-dependent phosphorylation promote radiotherapy resistance in head and neck cancer. Cell Oncol (Dordr) 2023:10.1007/s13402-023-00895-6. [PMID: 37971644 DOI: 10.1007/s13402-023-00895-6] [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] [Accepted: 10/23/2023] [Indexed: 11/19/2023] Open
Abstract
PURPOSE TIPRL1 (target of rapamycin signaling pathway regulator-like 1) is a known interactor and inhibitor of protein phosphatases PP2A, PP4 and PP6 - all pleiotropic modulators of the DNA Damage Response (DDR). Here, we investigated the role of TIPRL1 in the radiotherapy (RT) response of Head and Neck Squamous Cell Carcinoma (HNSCC). METHODS TIPRL1 mRNA (cBioportal) and protein expression (immunohistochemistry) in HNSCC samples were linked with clinical patient data. TIPRL1-depleted HNSCC cells were generated by CRISPR/Cas9 editing, and effects on colony growth, micronuclei formation (microscopy), cell cycle (flow cytometry), DDR signaling (immunoblots) and proteome (mass spectrometry) following RT were assessed. Mass spectrometry was used for TIPRL1 phosphorylation and interactomics analysis in irradiated cells. RESULTS TIPRL1 expression was increased in tumor versus non-tumor tissue, with high tumoral TIPRL1 expression associating with lower locoregional control and decreased survival of RT-treated patients. TIPRL1 deletion in HNSCC cells resulted in increased RT sensitivity, a faster but prolonged cell cycle arrest, increased micronuclei formation and an altered proteome-wide DDR. Upon irradiation, ATM phosphorylates TIPRL1 at Ser265. A non-phospho Ser265Ala mutant could not rescue the increased radiosensitivity phenotype of TIPRL1-depleted cells. While binding to PP2A-like phosphatases was confirmed, DNA-dependent protein kinase (DNA-PKcs), RAD51 recombinase and nucleosomal histones were identified as novel TIPRL1 interactors. Histone binding, although stimulated by RT, was adversely affected by TIPRL1 Ser265 phosphorylation. CONCLUSIONS Our findings underscore a clinically relevant role for TIPRL1 and its ATM-dependent phosphorylation in RT resistance through modulation of the DDR, highlighting its potential as a new HNSCC predictive marker and therapeutic target.
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Affiliation(s)
- Célie Cokelaere
- Laboratory of Protein Phosphorylation & Proteomics, Department of Cellular & Molecular Medicine, University of Leuven (KU Leuven), B-3000, Leuven, Belgium
- KU Leuven Cancer Institute (LKI), B-3000, Leuven, Belgium
| | - Rüveyda Dok
- KU Leuven Cancer Institute (LKI), B-3000, Leuven, Belgium
- Laboratory of Experimental Radiotherapy, Department of Oncology, University of Leuven (KU Leuven), B-3000, Leuven, Belgium
| | - Emanuela E Cortesi
- Translational Cell & Tissue Research, Department of Imaging & Pathology, University of Leuven (KU Leuven), B-3000, Leuven, Belgium
| | - Peihua Zhao
- VIB Laboratory of Mechanisms of Cell Transformation, Department of Oncology, University of Leuven (KU Leuven), B-3000, Leuven, Belgium
| | - Anna Sablina
- KU Leuven Cancer Institute (LKI), B-3000, Leuven, Belgium
- VIB Laboratory of Mechanisms of Cell Transformation, Department of Oncology, University of Leuven (KU Leuven), B-3000, Leuven, Belgium
| | - Sandra Nuyts
- KU Leuven Cancer Institute (LKI), B-3000, Leuven, Belgium
- Laboratory of Experimental Radiotherapy, Department of Oncology, University of Leuven (KU Leuven), B-3000, Leuven, Belgium
| | - Rita Derua
- Laboratory of Protein Phosphorylation & Proteomics, Department of Cellular & Molecular Medicine, University of Leuven (KU Leuven), B-3000, Leuven, Belgium
- SybioMA, Proteomics Core Facility, University of Leuven (KU Leuven), B-3000, Leuven, Belgium
| | - Veerle Janssens
- Laboratory of Protein Phosphorylation & Proteomics, Department of Cellular & Molecular Medicine, University of Leuven (KU Leuven), B-3000, Leuven, Belgium.
- KU Leuven Cancer Institute (LKI), B-3000, Leuven, Belgium.
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