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The prognostic significance of global aberrant alternative splicing in patients with myelodysplastic syndrome. Blood Cancer J 2018; 8:78. [PMID: 30104611 PMCID: PMC6089879 DOI: 10.1038/s41408-018-0115-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2018] [Revised: 07/11/2018] [Accepted: 07/18/2018] [Indexed: 12/22/2022] Open
Abstract
Aberrant alternative splicing (AS) is a hallmark of cancer development. However, there are limited data regarding its clinical implications in myelodysplastic syndrome (MDS). In this study, we performed an in-depth analysis of global AS in 176 primary MDS patients with 20 normal marrow transplant donors as reference. We found that 26.9% of the expressed genes genome-wide were aberrantly spliced in MDS patients compared with normal donors. These aberrant AS genes were related to pathways involved in cell proliferation, cell adhesion and protein degradation. A higher degree of global aberrant AS was associated with male gender and U2AF1 mutation, and predicted shorter overall survival and time to leukemic change. Moreover, it was an independent unfavorable prognostic factor irrespective of age, revised international prognostic scoring system (IPSS-R) risk, and mutations in SRSF2, ZRSR2, ASXL1, TP53, and EZH2. With LASSO-Cox regression method, we constructed a simple prognosis prediction model composed of 13 aberrant AS genes, and demonstrated that it could well stratify MDS patients into distinct risk groups. To our knowledge, this is the first report demonstrating significant prognostic impacts of aberrant splicing on MDS patients. Further prospective studies in larger cohorts are needed to confirm our observations.
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3
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Bertoli S, Boutzen H, David L, Larrue C, Vergez F, Fernandez-Vidal A, Yuan L, Hospital MA, Tamburini J, Demur C, Delabesse E, Saland E, Sarry JE, Galcera MO, Mansat-De Mas V, Didier C, Dozier C, Récher C, Manenti S. CDC25A governs proliferation and differentiation of FLT3-ITD acute myeloid leukemia. Oncotarget 2016; 6:38061-78. [PMID: 26515730 PMCID: PMC4741984 DOI: 10.18632/oncotarget.5706] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Accepted: 10/06/2015] [Indexed: 11/25/2022] Open
Abstract
We investigated cell cycle regulation in acute myeloid leukemia cells expressing the FLT3-ITD mutated tyrosine kinase receptor, an underexplored field in this disease. Upon FLT3 inhibition, CDC25A mRNA and protein were rapidly down-regulated, while levels of other cell cycle proteins remained unchanged. This regulation was dependent on STAT5, arguing for FLT3-ITD-dependent transcriptional regulation of CDC25A. CDC25 inhibitors triggered proliferation arrest and cell death of FLT3-ITD as well as FLT3-ITD/TKD AC-220 resistant cells, but not of FLT3-wt cells. Consistently, RNA interference-mediated knock-down of CDC25A reduced the proliferation of FLT3-ITD cell lines. Finally, the clonogenic capacity of primary FLT3-ITD AML cells was reduced by the CDC25 inhibitor IRC-083864, while FLT3-wt AML and normal CD34+ myeloid cells were unaffected. In good agreement, in a cohort of 100 samples from AML patients with intermediate-risk cytogenetics, high levels of CDC25A mRNA were predictive of higher clonogenic potential in FLT3-ITD+ samples, not in FLT3-wt ones.Importantly, pharmacological inhibition as well as RNA interference-mediated knock-down of CDC25A also induced monocytic differentiation of FLT3-ITD positive cells, as judged by cell surface markers expression, morphological modifications, and C/EBPα phosphorylation. CDC25 inhibition also re-induced monocytic differentiation in primary AML blasts carrying the FLT3-ITD mutation, but not in blasts expressing wild type FLT3. Altogether, these data identify CDC25A as an early cell cycle transducer of FLT3-ITD oncogenic signaling, and as a promising target to inhibit proliferation and re-induce differentiation of FLT3-ITD AML cells.
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Affiliation(s)
- Sarah Bertoli
- Cancer Research Center of Toulouse, Inserm UMR 1037, CNRS ERL 5294, Université de Toulouse, Oncopole, Toulouse, France.,Hematology Department, Institut Universitaire du Cancer Toulouse - Oncopole, Toulouse, France
| | - Helena Boutzen
- Cancer Research Center of Toulouse, Inserm UMR 1037, CNRS ERL 5294, Université de Toulouse, Oncopole, Toulouse, France
| | - Laure David
- Cancer Research Center of Toulouse, Inserm UMR 1037, CNRS ERL 5294, Université de Toulouse, Oncopole, Toulouse, France
| | - Clément Larrue
- Cancer Research Center of Toulouse, Inserm UMR 1037, CNRS ERL 5294, Université de Toulouse, Oncopole, Toulouse, France.,Institut Cochin, Université Paris Descartes, CNRS UMR 8104, INSERM U 1016, Paris, France
| | - François Vergez
- Cancer Research Center of Toulouse, Inserm UMR 1037, CNRS ERL 5294, Université de Toulouse, Oncopole, Toulouse, France.,Hematology Laboratory, Institut Universitaire du Cancer Toulouse - Oncopole, Toulouse, France
| | - Anne Fernandez-Vidal
- Cancer Research Center of Toulouse, Inserm UMR 1037, CNRS ERL 5294, Université de Toulouse, Oncopole, Toulouse, France
| | - Lingli Yuan
- Cancer Research Center of Toulouse, Inserm UMR 1037, CNRS ERL 5294, Université de Toulouse, Oncopole, Toulouse, France
| | - Marie-Anne Hospital
- Institut Cochin, Université Paris Descartes, CNRS UMR 8104, INSERM U 1016, Paris, France
| | - Jérôme Tamburini
- Institut Cochin, Université Paris Descartes, CNRS UMR 8104, INSERM U 1016, Paris, France
| | - Cécile Demur
- Hematology Laboratory, Institut Universitaire du Cancer Toulouse - Oncopole, Toulouse, France
| | - Eric Delabesse
- Cancer Research Center of Toulouse, Inserm UMR 1037, CNRS ERL 5294, Université de Toulouse, Oncopole, Toulouse, France.,Hematology Laboratory, Institut Universitaire du Cancer Toulouse - Oncopole, Toulouse, France
| | - Estelle Saland
- Cancer Research Center of Toulouse, Inserm UMR 1037, CNRS ERL 5294, Université de Toulouse, Oncopole, Toulouse, France
| | - Jean-Emmanuel Sarry
- Cancer Research Center of Toulouse, Inserm UMR 1037, CNRS ERL 5294, Université de Toulouse, Oncopole, Toulouse, France
| | | | - Véronique Mansat-De Mas
- Cancer Research Center of Toulouse, Inserm UMR 1037, CNRS ERL 5294, Université de Toulouse, Oncopole, Toulouse, France.,Hematology Laboratory, Institut Universitaire du Cancer Toulouse - Oncopole, Toulouse, France
| | - Christine Didier
- Cancer Research Center of Toulouse, Inserm UMR 1037, CNRS ERL 5294, Université de Toulouse, Oncopole, Toulouse, France
| | - Christine Dozier
- Cancer Research Center of Toulouse, Inserm UMR 1037, CNRS ERL 5294, Université de Toulouse, Oncopole, Toulouse, France
| | - Christian Récher
- Cancer Research Center of Toulouse, Inserm UMR 1037, CNRS ERL 5294, Université de Toulouse, Oncopole, Toulouse, France.,Hematology Department, Institut Universitaire du Cancer Toulouse - Oncopole, Toulouse, France
| | - Stéphane Manenti
- Cancer Research Center of Toulouse, Inserm UMR 1037, CNRS ERL 5294, Université de Toulouse, Oncopole, Toulouse, France
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4
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Skrdlant L, Stark JM, Lin RJ. Myelodysplasia-associated mutations in serine/arginine-rich splicing factor SRSF2 lead to alternative splicing of CDC25C. BMC Mol Biol 2016; 17:18. [PMID: 27552991 PMCID: PMC4994158 DOI: 10.1186/s12867-016-0071-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2016] [Accepted: 08/16/2016] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Serine-arginine rich splicing factor 2 (SRSF2) is a protein known for its role in RNA splicing and genome stability. It has been recently discovered that SRSF2, along with other splicing regulators, is frequently mutated in patients with myelodysplastic syndrome (MDS). The most common MDS mutations in SRSF2 occur at proline 95; the mutant proteins are shown to have different RNA binding preferences, which may contribute to splicing changes detected in mutant cells. However, the influence of these SRSF2 MDS-associated mutations on specific splicing events remains poorly understood. RESULTS A tetracycline-inducible TF-1 erythroleukemia cell line was transduced with retroviruses to create cell lines expressing HA-tagged wildtype SRSF2, SRSF2 with proline 95 point mutations found in MDS, or SRSF2 with a deletion of one of the four major domains of the protein. Effects of these mutants on apoptosis and specific alternative splicing events were evaluated. Cells were also treated with DNA damaging drugs for comparison. MDS-related P95 point mutants of SRSF2 were expressed and phosphorylated at similar levels as wildtype SRSF2. However, cells expressing mutant SRSF2 exhibited higher levels of apoptosis than cells expressing wildtype SRSF2. Regarding alternative splicing events, in nearly all examined cases, SRSF2 P95 mutants acted in a similar fashion as the wildtype SRSF2. However, cells expressing SRSF2 P95 mutants had a percent increase in the C5 spliced isoform of cell division cycle 25C (CDC25C). The same alternative splicing of CDC25C was detected by treating cells with DNA damaging drugs, such as cisplatin, camptothecin, and trichostatin A at appropriate dosage. However, unlike DNA damaging drugs, SRSF2 P95 mutants did not activate the Ataxia telangiectasia mutated (ATM) pathway. CONCLUSION SRSF2 P95 mutants lead to alternative splicing of CDC25C in a manner that is not dependent on the DNA damage response.
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Affiliation(s)
- Lindsey Skrdlant
- Department of Molecular and Cellular Biology, Irell & Manella Graduate School of Biological Sciences, Beckman Research Institute of the City of Hope, Duarte, CA 91010 USA
| | - Jeremy M. Stark
- Department of Cancer Genetics and Epigenetics, Irell & Manella Graduate School of Biological Sciences, Beckman Research Institute of the City of Hope, Duarte, CA 91010 USA
| | - Ren-Jang Lin
- Department of Molecular and Cellular Biology, Irell & Manella Graduate School of Biological Sciences, Beckman Research Institute of the City of Hope, Duarte, CA 91010 USA
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Brenner AK, Reikvam H, Lavecchia A, Bruserud Ø. Therapeutic targeting the cell division cycle 25 (CDC25) phosphatases in human acute myeloid leukemia--the possibility to target several kinases through inhibition of the various CDC25 isoforms. Molecules 2014; 19:18414-47. [PMID: 25397735 PMCID: PMC6270710 DOI: 10.3390/molecules191118414] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Revised: 10/28/2014] [Accepted: 11/02/2014] [Indexed: 01/26/2023] Open
Abstract
The cell division cycle 25 (CDC25) phosphatases include CDC25A, CDC25B and CDC25C. These three molecules are important regulators of several steps in the cell cycle, including the activation of various cyclin-dependent kinases (CDKs). CDC25s seem to have a role in the development of several human malignancies, including acute myeloid leukemia (AML); and CDC25 inhibition is therefore considered as a possible anticancer strategy. Firstly, upregulation of CDC25A can enhance cell proliferation and the expression seems to be controlled through PI3K-Akt-mTOR signaling, a pathway possibly mediating chemoresistance in human AML. Loss of CDC25A is also important for the cell cycle arrest caused by differentiation induction of malignant hematopoietic cells. Secondly, high CDC25B expression is associated with resistance against the antiproliferative effect of PI3K-Akt-mTOR inhibitors in primary human AML cells, and inhibition of this isoform seems to reduce AML cell line proliferation through effects on NFκB and p300. Finally, CDC25C seems important for the phenotype of AML cells at least for a subset of patients. Many of the identified CDC25 inhibitors show cross-reactivity among the three CDC25 isoforms. Thus, by using such cross-reactive inhibitors it may become possible to inhibit several molecular events in the regulation of cell cycle progression and even cytoplasmic signaling, including activation of several CDKs, through the use of a single drug. Such combined strategies will probably be an advantage in human cancer treatment.
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Affiliation(s)
- Annette K Brenner
- Section for Hematology, Institute of Clinical Science, Faculty of Medicine and Dentistry, University of Bergen, Bergen, 5021, Norway
| | - Håkon Reikvam
- Section for Hematology, Institute of Clinical Science, Faculty of Medicine and Dentistry, University of Bergen, Bergen, 5021, Norway
| | - Antonio Lavecchia
- "Drug Discovery" Laboratory, Department of Pharmacy, University of Naples Federico II, Naples 80131, Italy
| | - Øystein Bruserud
- Section for Hematology, Institute of Clinical Science, Faculty of Medicine and Dentistry, University of Bergen, Bergen, 5021, Norway.
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Albert H, Santos S, Battaglia E, Brito M, Monteiro C, Bagrel D. Differential expression of CDC25 phosphatases splice variants in human breast cancer cells. Clin Chem Lab Med 2011; 49:1707-14. [PMID: 21675940 DOI: 10.1515/cclm.2011.635] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
BACKGROUND CDC25 phosphatases control cell cycle progression by activating cyclin dependent kinases. The three CDC25 isoforms encoding genes are submitted to alternative splicing events which generate at least two variants for CDC25A and five for both CDC25B and CDC25C. An over-expression of CDC25 was reported in several types of cancer, including breast cancer, and is often associated with a poor prognosis. Nevertheless, most of the previous studies did not address the expression of CDC25 splice variants. Here, we evaluated CDC25 spliced transcripts expression in anti-cancerous drug-sensitive and resistant breast cancer cell lines in order to identify potential breast cancer biomarkers. METHODS CDC25 splice variants mRNA levels were evaluated by semi-quantitative RT-PCR and by an original real-time RT-PCR assay. RESULTS CDC25 spliced transcripts are differentially expressed in the breast cancer cell lines studied. An up-regulation of CDC25A2 variant and an increase of the CDC25C5/C1 ratio are associated to the multidrug-resistance in VCREMS and DOXOR breast cancer cells, compared to their sensitive counterpart cell line MCF-7. Additionally, CDC25B2 transcript is exclusively over-expressed in VCREMS resistant cells and could therefore be involved in the development of certain type of drug resistance. CONCLUSIONS CDC25 splice variants could represent interesting potential breast cancer prognostic biomarkers.
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Affiliation(s)
- Hélène Albert
- Laboratoire d'Ingénierie Moléculaire et Biochimie Pharmacologique, EA 3940, FR CNRS 2843, Université Paul Verlaine-Metz, Metz, France
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