1
|
Miyanishi K, Nururrozi A, Igase M, Tanabe M, Sakurai M, Sakai Y, Shimonohara N, Murakami M, Mizuno T. Activation of the Akt signalling pathway as a prognostic indicator in canine soft tissue sarcoma. J Comp Pathol 2023; 206:44-52. [PMID: 37839309 DOI: 10.1016/j.jcpa.2023.08.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 04/18/2023] [Accepted: 08/31/2023] [Indexed: 10/17/2023]
Abstract
Canine soft tissue sarcoma (STS) is relatively common in dogs and is the generic term for tumours that originate from mesenchymal cells. While histopathological grade and immunolabelling with Ki-67 have been used for estimating prognosis, additional indicators are needed for predicting prognosis. Aberrant cell signalling pathways may contribute to disease activity and, therefore, prognostic markers. However, their role in canine STS remains poorly understood. The aim of this study was to investigate expression of phosphorylated Akt (phospho-Akt) and phosphorylated S6 (phospho-S6) as potential prognostic indicators. Immunohistochemical labelling was conducted on clinical samples of canine STS (n = 67). We found that phospho-Akt expression was positively correlated with histopathological grade (P = 0.001) and Ki-67 index (P <0.01). There was no apparent relationship between the type of STS and the expression of phospho-Akt. The number of cases that expressed phospho-S6, which is the downstream molecule of the Akt signalling pathway, was higher in immunopositive phospho-Akt cases than in immunonegative phospho-Akt cases (P <0.0001). Furthermore, phospho-Akt expression was significantly higher in recurrent and metastatic cases. We also confirmed that phosphorylation of Akt occurred in conjunction with S6 phosphorylation in three canine STS cell lines. These results suggest that immunolabelling for phospho-Akt, phospho-S6 and Ki-67 could potentially be used as a prognostic indicator and therapeutic target in canine STS.
Collapse
Affiliation(s)
- Kyohei Miyanishi
- Laboratory of Molecular Diagnostics and Therapeutics, Joint Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan
| | - Alfarisa Nururrozi
- Laboratory of Molecular Diagnostics and Therapeutics, Joint Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan
| | - Masaya Igase
- Laboratory of Molecular Diagnostics and Therapeutics, Joint Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan
| | - Mika Tanabe
- Veterinary Pathology Diagnostic Center, Fukuoka, Japan
| | - Masashi Sakurai
- Laboratory of Veterinary Pathology, Joint Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan
| | - Yusuke Sakai
- Laboratory of Veterinary Pathology, Joint Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan
| | | | - Mami Murakami
- Laboratory of Veterinary Clinical Oncology, Joint Department of Veterinary Medicine, Gifu University, Gifu, Japan
| | - Takuya Mizuno
- Laboratory of Molecular Diagnostics and Therapeutics, Joint Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan.
| |
Collapse
|
2
|
Huang TL, Pian JP, Pan BT. Oncogenic Ras suppresses Cdk1 in a complex manner during the incubation of activated Xenopus egg extracts. Arch Biochem Biophys 2013; 532:61-72. [PMID: 23376039 DOI: 10.1016/j.abb.2013.01.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Revised: 01/12/2013] [Accepted: 01/18/2013] [Indexed: 12/30/2022]
Abstract
The activity of Cdk1 is the driving force for entry into M-phase during the cell cycle. Activation of Cdk1 requires synthesis and accumulation of cyclin B, binding of cyclin B to Cdk1, and removal of the inhibitory tyr-15-Cdk1 phosphorylation. It was previously shown that oncogenic Ras suppresses Cdk1 activation during the incubation of activated Xenopus egg extracts. However, how oncogenic Ras suppresses Cdk1 remained unclear. Using the histone H1 kinase assay to follow Cdk1 activity and Western blot analysis to assess levels of both cyclin B2 and phosphorylated-tyr-15-Cdk1, how oncogenic Ras suppresses Cdk1 is studied. The results indicate that oncogenic Ras suppresses Cdk1 via induction of persistent phosphorylation of tyr-15-Cdk1. Interestingly, the results reveal that, compared with cyclin B2 in control activated egg extracts, which increased, peaked and then declined during the incubation, oncogenic Ras induced continuous accumulation of cyclin B2. The results also indicate that oncogenic Ras induces continuous accumulation of cyclin B2 primarily through stabilization of cyclin B2, which is mediated by constitutive activation of the Raf-Mek-Erk-p90(rsk) pathway. Taken together, these results indicate that oncogenic Ras suppresses Cdk1 in a complex manner: It induces continuous accumulation of cyclin B2, but also causes persistent inhibitory phosphorylation of tyr-15-Cdk1.
Collapse
Affiliation(s)
- Tun-Lan Huang
- Graduate Center for Nutritional Sciences, University of Kentucky College of Medicine, Lexington, KY 40536, USA
| | | | | |
Collapse
|
3
|
Pian JP, Huang TL, Tsai PC, Shi JP, Cu H, Pan BT. A 32 kDa protein?whose phosphorylation correlates with oncogenic Ras-induced cell cycle arrest in activatedXenopus egg extracts?is identified as ribosomal protein S6. J Cell Physiol 2004; 201:305-19. [PMID: 15334665 DOI: 10.1002/jcp.20069] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Oncogenic Ras induces cell-cycle arrest in mammalian cells and in fertilized Xenopus eggs. How oncogenic Ras induces cell-cycle arrest remains unclear. We previously showed that oncogenic Ras induces cell-cycle arrest in activated Xenopus egg extracts (cycling extracts) and that the induced cell-cycle arrest correlates with hyperphosphorylation of a 32 kDa protein. However, the identity of the 32 kDa protein was not known. By using a sucrose density-gradient centrifugation, Triton X-100-acetic acid-urea (TAU)-gel electrophoresis, composite agarose-polyacrylamide gel electrophoresis (CAPAGE), SDS-PAGE, and partial tryptic peptide sequence analysis, the 32 kDa protein has now been identified as S6, a 40S subunit ribosomal protein. Hence, our results indicate that the oncogenic Ras-induced cell-cycle arrest is correlated with hyperphosphorylation of S6, suggesting that phosphorylation of S6 plays an important role in the induced cell-cycle arrest. It has been shown that conditional deletion of gene encoding S6 in mammalian cells prevents proliferation, demonstrating the importance of S6 in cell proliferation. The exact role S6 plays in cell proliferation is unclear. However, phosphorylation of S6 has been implicated in the regulation of protein synthesis. Thus, our results are consistent with the concept that oncogenic Ras induces S6 phosphorylation to influence protein synthesis, thereby contributing to the cell-cycle arrest. In addition, our results also demonstrate that composite agarose-polyacrylamide gel electrophoresis is suitable for the separation of large molecular complexes.
Collapse
Affiliation(s)
- Jerry Pinghwa Pian
- Graduate Center for Nutritional Sciences, University of Kentucky Medical Center, 800 Rose Street, Lexington, Kentucky 40536, USA
| | | | | | | | | | | |
Collapse
|
4
|
Mowat MR, Stewart N. Mechanisms of cell cycle blocks at the G2/M transition and their role in differentiation and development. PROGRESS IN MOLECULAR AND SUBCELLULAR BIOLOGY 1999; 20:73-100. [PMID: 9928527 DOI: 10.1007/978-3-642-72149-6_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Affiliation(s)
- M R Mowat
- Manitoba Institute of Cell Biology, Manitoba Cancer Treatment and Research Foundation, Winnipeg, Canada
| | | |
Collapse
|
5
|
Gómez J, Martínez-A C, González A, Rebollo A. Dual role of Ras and Rho proteins: at the cutting edge of life and death. Immunol Cell Biol 1998; 76:125-34. [PMID: 9619482 DOI: 10.1046/j.1440-1711.1998.00723.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Small GTP-binding proteins of the Ras superfamily are master controllers of the cell physiology. The range of processes in which these proteins are involved include cell cycle progression, cell division, regulation of cell morphology and motility and intracellular trafficking of molecules and organelles. The study of apoptosis, the physiological form of cell suicide, is progressively linking the functions of small G proteins to the control of the mechanisms that trigger the genetic programmes of cell death. To date, isoforms of the Ras and Rho groups have been related to both promotion and suppression of apoptosis. Further, signalling pathways driven by these proteins have been associated with the function and/or expression of molecules that regulate apoptotic responses. Thus, all available evidence points to a critical role for Ras and Rho proteins as major gatekeepers of the decision between cellular life and death.
Collapse
Affiliation(s)
- J Gómez
- Department of Immunology and Oncology, Centro Nacional de Biotecnología, Universidad Autónoma de Madrid, Spain
| | | | | | | |
Collapse
|
6
|
Murakami MS, Vande Woude GF. Analysis of the early embryonic cell cycles of Xenopus; regulation of cell cycle length by Xe-wee1 and Mos. Development 1998; 125:237-48. [PMID: 9486797 DOI: 10.1242/dev.125.2.237] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In Xenopus, cdc2 tyrosine phosphorylation is detected in the first 60–75 minute cell cycle but not in the next eleven cell cycles (cycles 2–12) which are only 30 minutes long. Here we report that the wee1/cdc25 ratio increases before the first mitotic interphase. We show that the Xe-wee1 protein is absent in stage VI oocytes and is expressed from meiosis II until gastrulation. A dominant negative form of Xe-wee1 (KM wee1) reduced the level cdc2 tyrosine phosphorylation and length of the first cycle. However, the ratio of wee1/cdc25 did not decrease after the first cycle and therefore did not explain the lack of cdc2 tyrosine phosphorylation in, nor the rapidity of, cycles 2–12. Furthermore, there was no evidence for a wee1/myt1 inhibitor in cycles 2–12. We examined the role of Mos in the first cycle because it is present during the first 20 minutes of this cycle. We arrested the rapid embryonic cell cycle (cycle 2 or 3) with Mos and restarted the cell cycle with calcium ionophore; the 30 minute cycle was converted into a 60 minute cycle, with cdc2 tyrosine phosphorylation. In addition, the injection of a non-degradable Mos (MBP-Mos) into the first cycle resulted in a dramatic elongation of this cycle (to 140 minutes). MBP-Mos did not delay DNA replication or the translation of cyclins A or B; it did, however, result in the marked accumulation of tyrosine phosphorylated cdc2. Thus, while the wee1/cdc25 ratio changes during development, these changes may not be responsible for the variety of cell cycles observed during early Xenopus embryogenesis. Our experiments indicate that Mos/MAPK can also contribute to cell cycle length.
Collapse
Affiliation(s)
- M S Murakami
- ABL-Basic Research Program, NCI-Frederick Cancer Research and Development Center, MD 21702, USA
| | | |
Collapse
|
7
|
Pan BT, Shi JP, Chen HJ, Roberts C, Chen DH, Wang JW. Identification of a potential physiological substrate for oncogenic Ras-activated protein kinases in activated Xenopus egg extracts: correlation with oncogenic Ras-induced cell cycle arrest. J Cell Physiol 1996; 169:149-58. [PMID: 8841431 DOI: 10.1002/(sici)1097-4652(199610)169:1<149::aid-jcp15>3.0.co;2-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Activated Xenopus egg extracts are capable of undergoing cell-free cell cycling. Using these activated extracts, we previously showed that purified, bacterially expressed oncogenic human RasH protein arrests cell cycle progression. Because oncogenic Ras activates many serine/threonine protein kinases in Xenopus oocytes and egg extracts, it is possible that induction of cell cycle arrest involves the action of oncogenic Ras-activated kinases. Thus, the identification of the physiological substrates for oncogenic Ras-activated kinases is important for elucidating the molecular mechanism underlying oncogenic Ras-induced cell cycle arrest. We used 32P-orthophosphate as a label to identify the potential substrates. Our results demonstrated that the 32P-labeling of both a 32 and a 33 kDa protein were greatly enhanced by oncogenic Ras during the incubation of activated Xenopus egg extracts. The enhanced labeling correlated with the induced cell cycle arrest and was contributed by serine phosphorylation. Moreover, the 33 kDa protein was detected only in the presence of oncogenic Ras and was a serine-hyperphosphorylated form of the 32 kDa protein. Furthermore, new protein synthesis was not required for the enhanced labeling, consistent with the concept that the enhanced serine phosphorylation of the 32 kDa protein is by oncogenic Ras-activated protein kinases. In addition to serine phosphorylation, our results also suggested that an as yet unidentified modification of the 32 kDa protein might also be induced by oncogenic Ras. Our results suggest that the 32 kDa protein is a potential physiological substrate for oncogenic Ras-activated protein kinases.
Collapse
Affiliation(s)
- B T Pan
- Department of Surgery, University of Kentucky Chandler Medical Center, Lexington 40536, USA
| | | | | | | | | | | |
Collapse
|
8
|
Albanese C, Johnson J, Watanabe G, Eklund N, Vu D, Arnold A, Pestell RG. Transforming p21ras mutants and c-Ets-2 activate the cyclin D1 promoter through distinguishable regions. J Biol Chem 1995; 270:23589-97. [PMID: 7559524 DOI: 10.1074/jbc.270.40.23589] [Citation(s) in RCA: 636] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Several different oncogenes and growth factors promote G1 phase progression. Cyclin D1, the regulatory subunit of several cyclin-dependent kinases, is required for, and capable of shortening, the G1 phase of the cell cycle. The present study demonstrates that transforming mutants of p21ras (Ras Val-12, Ras Leu-61) induce the cyclin D1 promoter in human trophoblasts (JEG-3), mink lung epithelial (Mv1.Lu), and in Chinese hamster ovary fibroblast cell lines. Site-directed mutagenesis of AP-1-like sequences at -954 abolished p21ras-dependent activation of cyclin D1 expression. The AP-1-like sequences were also required for activation of the cyclin D1 promoter by c-Jun. In electrophoretic mobility shift assays using nuclear extracts from cultured cells and primary tissues, several AP-1 proteins (c-Jun, JunB, JunD, and c-Fos) bound the cyclin D1 -954 region. Cyclin D1 promoter activity was stimulated by overexpression of mitogen-activated protein kinase (p41MAPK) or c-Ets-2 through the proximal 22 base pairs. Expression of plasmids encoding either dominant negative MAPK (p41MAPKi) or dominant negatives of ETS activation (Ets-LacZ), antagonized MAPK-dependent induction of cyclin D1 promoter activity. Epidermal growth factor induction of cyclin D1 transcription, through the proximal promoter region, was antagonized by either p41MAPKi or Ets-LacZ, suggesting that ETS functions downstream of epidermal growth factor and MAPK in the context of the cyclin D1 promoter. The activation of cyclin D1 transcription by p21ras provides evidence for cross-talk between the p21ras and cell cycle regulatory pathways.
Collapse
Affiliation(s)
- C Albanese
- Division of Endocrinology, Metabolism, and Molecular Medicine, Northwestern University Medical School, Chicago, Illinois 60611, USA
| | | | | | | | | | | | | |
Collapse
|
9
|
Chen CT, Pan BT. Oncogenic ras stimulates a 96-kDa histone H2b kinase activity in activated Xenopus egg extracts. Correlation with the suppression of p34cdc2 kinase. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(18)46891-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
|