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Brożyna AA, Aplin A, Cohen C, Carlson G, Page AJ, Murphy M, Slominski AT, Carlson JA. CKS1 expression in melanocytic nevi and melanoma. Oncotarget 2018; 9:4173-4187. [PMID: 29423113 PMCID: PMC5790530 DOI: 10.18632/oncotarget.23648] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 12/16/2017] [Indexed: 12/22/2022] Open
Abstract
Cyclin-dependent kinase subunit 1 (Cks1) regulates the degradation of p27, an important G1-S inhibitor, which is up regulated by MAPK pathway activation. In this study, we sought to determine whether Cks1 expression is increased in melanocytic tumors and correlates with outcome and/or other clinicopathologic prognostic markers. Cks1 expression was assessed by immunohistochemistry in 298 melanocytic lesions. The frequency and intensity of cytoplasmic and nuclear expression was scored as a labeling index and correlated with clinico-pathological data. Nuclear Cks1 protein was found in 63% of melanocytic nevi, 89% primary and 90% metastatic melanomas with mean labeling index of 7 ± 16, 19 ± 20, and 30 ± 29, respectively. While cytoplasmic Cks1 was found in 41% of melanocytic nevi, 84% primary and 95% metastatic melanomas with mean labeling index of 18 ± 34, 35 ± 34, and 52 ± 34, accordingly. Histologic stepwise model of tumor progression, defined as progression from benign nevi to primary melanomas, to melanoma metastases, revealed a significant increase in nuclear and cytoplasmic Cks1 expression with tumor progression. Nuclear and cytoplasmic Cks1 expression correlated with the presence of ulceration, increased mitotic rate, Breslow depth, Clark level, tumor infiltrating lymphocytes and gender. However, other well-known prognostic factors (age, anatomic site, and regression) did not correlate with any type of Cks1 expression. Similarly, increasing nuclear expression of Cks1 significantly correlated with worse overall survival. Thus, Cks1 expression appears to play a role in the progression of melanoma, where high levels of expression are associated with poor outcome. Cytoplasmic expression of Cks1 might represent high turnover of protein via the ubiquination/proteosome pathway.
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Affiliation(s)
- Anna A Brożyna
- Department of Tumor Pathology and Pathomorphology, Faculty of Health Sciences, Nicolaus Copernicus University Collegium Medicum in Bydgoszcz, Oncology Centre - Prof. Franciszek Łukaszczyk Memorial Hospital, Bydgoszcz 85-796, Poland
| | - Andrew Aplin
- Department of Cancer Biology, BLSB 524, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Cynthia Cohen
- Winship Cancer Institute, Emory University Hospital, Atlanta, GA 30322, USA
| | - Grant Carlson
- Winship Cancer Institute, Emory University Hospital, Atlanta, GA 30322, USA
| | - Andrew Joseph Page
- Pancreas, Liver, and Cancer Surgery, Piedmont Healthcare, Atlanta, GA 30309, USA
| | - Michael Murphy
- Department of Dermatology, UConn Health, Farmington, CT 06030, USA
| | - Andrzej T Slominski
- Department of Dermatology, Comprehensive Cancer Center, Cancer Chemoprevention Program, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - J Andrew Carlson
- Department of Pathology and Laboratory Medicine, Albany Medical College MC-81, Albany, NY 12208, USA
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CKS Proteins Promote Checkpoint Recovery by Stimulating Phosphorylation of Treslin. Mol Cell Biol 2017; 37:MCB.00344-17. [PMID: 28739856 DOI: 10.1128/mcb.00344-17] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 07/11/2017] [Indexed: 01/01/2023] Open
Abstract
CKS proteins are small (9-kDa) polypeptides that bind to a subset of the cyclin-dependent kinases. The two paralogs expressed in mammals, Cks1 and Cks2, share an overlapping function that is essential for early development. However, both proteins are frequently overexpressed in human malignancy. It has been shown that CKS protein overexpression overrides the replication stress checkpoint, promoting continued origin firing. This finding has led to the proposal that CKS protein-dependent checkpoint override allows premalignant cells to evade oncogene stress barriers, providing a causal link to oncogenesis. Here, we provide mechanistic insight into how overexpression of CKS proteins promotes override of the replication stress checkpoint. We show that CKS proteins greatly enhance the ability of Cdk2 to phosphorylate the key replication initiation protein treslin in vitro Furthermore, stimulation of treslin phosphorylation does not occur by the canonical adapter mechanism demonstrated for other substrates, as cyclin-dependent kinase (CDK) binding-defective mutants are capable of stimulating treslin phosphorylation. This effect is recapitulated in vivo, where silencing of Cks1 and Cks2 decreases treslin phosphorylation, and overexpression of wild-type or CDK binding-defective Cks2 prevents checkpoint-dependent dephosphorylation of treslin. Finally, we provide evidence that the role of CKS protein-dependent checkpoint override involves recovery from checkpoint-mediated arrest of DNA replication.
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Yue X, Que Y, Deng S, Xu L, Oses-Ruiz M, Talbot NJ, Peng Y, Wang Z. The cyclin dependent kinase subunit Cks1 is required for infection-associated development of the rice blast fungusMagnaporthe oryzae. Environ Microbiol 2017; 19:3959-3981. [DOI: 10.1111/1462-2920.13796] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 03/30/2017] [Accepted: 05/08/2017] [Indexed: 11/27/2022]
Affiliation(s)
- Xiaofeng Yue
- State Key Laboratory for Rice Biology; Institute of Biotechnology, Zhejiang University; Hangzhou 310058, China
| | - Yawei Que
- State Key Laboratory for Rice Biology; Institute of Biotechnology, Zhejiang University; Hangzhou 310058, China
| | - Shuzhen Deng
- State Key Laboratory for Rice Biology; Institute of Biotechnology, Zhejiang University; Hangzhou 310058, China
| | - Lin Xu
- State Key Laboratory for Rice Biology; Institute of Biotechnology, Zhejiang University; Hangzhou 310058, China
| | - Miriam Oses-Ruiz
- School of Biosciences; University of Exeter, Geoffrey Pope Building; Exeter EX4 4QD UK
| | - Nicholas J. Talbot
- School of Biosciences; University of Exeter, Geoffrey Pope Building; Exeter EX4 4QD UK
| | - Youliang Peng
- State Key Laboratory of Agribiotechnology and MOA Key Laboratory of Plant Pathology; China Agricultural University; Beijing 100193, People's Republic of China
| | - Zhengyi Wang
- State Key Laboratory for Rice Biology; Institute of Biotechnology, Zhejiang University; Hangzhou 310058, China
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