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Oviya RP, Thangaretnam KP, Ramachandran B, Ramanathan P, Jayavelu S, Gopal G, Rajkumar T. Mitochondrial ribosomal small subunit (MRPS) MRPS23 protein-protein interaction reveals phosphorylation by CDK11-p58 affecting cell proliferation and knockdown of MRPS23 sensitizes breast cancer cells to CDK1 inhibitors. Mol Biol Rep 2022; 49:9521-9534. [PMID: 35962848 DOI: 10.1007/s11033-022-07842-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 08/04/2022] [Indexed: 11/29/2022]
Abstract
BACKGROUND Post-translational modification of some mitoribosomal proteins has been found to regulate their functions. MRPS23 has been reported to be overexpressed in various cancers and has been predicted to be involved in increased cell proliferation. Furthermore, MRPS23 is a driver of luminal subtype breast cancer. However, its exact role and function in cancer remains unknown. METHODS AND RESULTS: Our previous study identified protein-protein interactions involving MRPS23 and CDK11A. In this study, we confirmed the interaction of MRPS23 with the p110 and p58 isoforms of CDK11A. Phosphoprotein enrichment studies and in vitro kinase assay using CDK11A/cyclin D3 followed by MALDI-ToF/ToF analysis confirmed the phosphorylation of MRPS23 at N-terminal serine 11 residue. Breast cancer cells expressing the MRPS23 (S11G) mutant showed increased cell proliferation, increased expression of PI3-AKT pathway proteins [p-AKT (Ser47), p-AKT (Thr308), p-PDK (Ser241) and p-GSK-3β (Ser9)] and increased antiapoptotic pathway protein expression [Bcl-2, Bcl-xL, p-Bcl2 (Ser70) and MCL-1] when compared with the MRPS23 (S11A) mutant-overexpressing cells. This finding indicated the role of MRPS23 phosphorylation in the proliferation and survival of breast cancer cells. The correlation of inconsistent MRPS23 phosphoserine 11 protein expression with CDK11A in the breast cancer cells suggested phosphorylation by other kinases. In vitro kinase assay showed that CDK1 kinase also phosphorylated MRPS23 and that inhibition using CDK1 inhibitors lowered phospho-MRPS23 (Ser11) levels. Additionally, modulating the expression of MRPS23 altered the sensitivity of the cells to CDK1 inhibitors. CONCLUSION In conclusion, phosphorylation of MRPS23 by mitotic kinases might potentially be involved in the proliferation of breast cancer cells. Furthermore, MRPS23 can be targeted for sensitizing the breast cancer cells to CDK1 inhibitors.
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Affiliation(s)
| | | | - Balaji Ramachandran
- Department of Molecular Oncology, Cancer Institute (WIA), Adyar, Chennai, Tamil Nadu, 600020, India
| | - Priya Ramanathan
- Department of Molecular Oncology, Cancer Institute (WIA), Adyar, Chennai, Tamil Nadu, 600020, India
| | - Subramani Jayavelu
- Department of Molecular Oncology, Cancer Institute (WIA), Adyar, Chennai, Tamil Nadu, 600020, India
| | - Gopisetty Gopal
- Department of Molecular Oncology, Cancer Institute (WIA), Adyar, Chennai, Tamil Nadu, 600020, India. .,Department of Molecular Oncology, Cancer Institute (WIA), Chennai, 600036, India.
| | - Thangarajan Rajkumar
- Department of Molecular Oncology, Cancer Institute (WIA), Adyar, Chennai, Tamil Nadu, 600020, India
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Li L, Tao X, Li Y, Gao Y, Li Q. CDC37L1 acts as a suppressor of migration and proliferation in gastric cancer by down-regulating CDK6. J Cancer 2021; 12:3145-3153. [PMID: 33976724 PMCID: PMC8100790 DOI: 10.7150/jca.56097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Accepted: 03/17/2021] [Indexed: 11/18/2022] Open
Abstract
The co-chaperone protein CDC37 (Cell division cycle 37) is well known to regulate multiple protein kinases and involved in tumor progression. However to date, little is known about its analogue CDC37L1 (Cell division cycle 37 like 1) in tumorigenesis. This study aimed to explore the expression and function of CDC37L1 in gastric cancer (GC). The immunohistochemical staining in a tissue microarray showed a weak expression of CDC37L1 in high grade GC tissues compared with low grade tissues. Consistently, data from online database analysis demonstrated that CDC37L1 level was decreased in stage 4 patients and low expression of CDC37L1 indicated a poor prognosis. Functional studies revealed that CDC37L1 could inhibit GC cell proliferation and migration in CCK8, EdU incorporation, colony formation and transwell assays. In the meantime, CDC37L1 also inhibited the tumorigenicity of GC cells in nude mice. Mechanistically, we found that CDC37L1 had an impact on CDK6 protein expression by western blotting. Palbociclib, a specific CDK4/6 inhibitor, was discovered to block the rapid growth phenotype of GC cells induced by CDC37L1 silencing. Taken together, these findings unveiled a tumor-suppressive role of CDC37L1 in GC, and CDK6 may act as a downstream effector in this process.
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Affiliation(s)
- Li Li
- Department of Oncology, Shanghai East Hospital, Tongji University School of Medicine, Shanghai 200120, China
| | - Xinyi Tao
- Department of Oncology, Shanghai East Hospital, Tongji University School of Medicine, Shanghai 200120, China
- Department of Medical Experimental Techniques, Jinzhou Medical University, Jinzhou 121001, China
| | - Yandong Li
- Department of Oncology, Shanghai East Hospital, Tongji University School of Medicine, Shanghai 200120, China
| | - Yong Gao
- Department of Oncology, Shanghai East Hospital, Tongji University School of Medicine, Shanghai 200120, China
| | - Qinchuan Li
- Department of Thoracic Surgery, Shanghai East Hospital, Tongji University School of Medicine, Shanghai 200120, China
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