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Dash S, Ueda T, Komuro A, Honda M, Sugisawa R, Okada H. Deoxycytidine kinase inactivation enhances gemcitabine resistance and sensitizes mitochondrial metabolism interference in pancreatic cancer. Cell Death Dis 2024; 15:131. [PMID: 38346958 PMCID: PMC10861559 DOI: 10.1038/s41419-024-06531-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 01/28/2024] [Accepted: 02/01/2024] [Indexed: 02/15/2024]
Abstract
Pancreatic ductal adenocarcinoma (PDAC) is considered one of the most lethal forms of cancer. Although in the last decade, an increase in 5-year patient survival has been observed, the mortality rate remains high. As a first-line treatment for PDAC, gemcitabine alone or in combination (gemcitabine plus paclitaxel) has been used; however, drug resistance to this regimen is a growing issue. In our previous study, we reported MYC/glutamine dependency as a therapeutic target in gemcitabine-resistant PDAC secondary to deoxycytidine kinase (DCK) inactivation. Moreover, enrichment of oxidative phosphorylation (OXPHOS)-associated genes was a common property shared by PDAC cell lines, and patient clinical samples coupled with low DCK expression was also demonstrated, which implicates DCK in cancer metabolism. In this article, we reveal that the expression of most genes encoding mitochondrial complexes is remarkably upregulated in PDAC patients with low DCK expression. The DCK-knockout (DCK KO) CFPAC-1 PDAC cell line model reiterated this observation. Particularly, OXPHOS was functionally enhanced in DCK KO cells as shown by a higher oxygen consumption rate and mitochondrial ATP production. Electron microscopic observations revealed abnormal mitochondrial morphology in DCK KO cells. Furthermore, DCK inactivation exhibited reactive oxygen species (ROS) reduction accompanied with ROS-scavenging gene activation, such as SOD1 and SOD2. SOD2 inhibition in DCK KO cells clearly induced cell growth suppression. In combination with increased anti-apoptotic gene BCL2 expression in DCK KO cells, we finally reveal that venetoclax and a mitochondrial complex I inhibitor are therapeutically efficacious for DCK-inactivated CFPAC-1 cells in in vitro and xenograft models. Hence, our work provides insight into inhibition of mitochondrial metabolism as a novel therapeutic approach to overcome DCK inactivation-mediated gemcitabine resistance in PDAC patient treatment.
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Affiliation(s)
- Suman Dash
- Department of Biochemistry, Kindai University Faculty of Medicine, Osakasayama, Osaka, 589-8511, Japan
- Graduate School of Medical Sciences, Kindai University Faculty of Medicine, Osakasayama, Osaka, 589-8511, Japan
| | - Takeshi Ueda
- Department of Biochemistry, Kindai University Faculty of Medicine, Osakasayama, Osaka, 589-8511, Japan
- Graduate School of Medical Sciences, Kindai University Faculty of Medicine, Osakasayama, Osaka, 589-8511, Japan
| | - Akiyoshi Komuro
- Department of Biochemistry, Kindai University Faculty of Medicine, Osakasayama, Osaka, 589-8511, Japan
| | - Masahiko Honda
- Department of Biochemistry, Kindai University Faculty of Medicine, Osakasayama, Osaka, 589-8511, Japan
| | - Ryoichi Sugisawa
- Department of Biochemistry, Kindai University Faculty of Medicine, Osakasayama, Osaka, 589-8511, Japan
| | - Hitoshi Okada
- Department of Biochemistry, Kindai University Faculty of Medicine, Osakasayama, Osaka, 589-8511, Japan.
- Graduate School of Medical Sciences, Kindai University Faculty of Medicine, Osakasayama, Osaka, 589-8511, Japan.
- Anti-aging Center, Kindai University, Higashi-Osaka, Osaka, 577-8502, Japan.
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Al Barashdi MAS, Ali A, McMullin MF, Mills K. CD45 inhibition in myeloid leukaemia cells sensitizes cellular responsiveness to chemotherapy. Ann Hematol 2024; 103:73-88. [PMID: 37917373 PMCID: PMC10761371 DOI: 10.1007/s00277-023-05520-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 10/24/2023] [Indexed: 11/04/2023]
Abstract
Myeloid malignancies are a group of blood disorders characterized by the proliferation of one or more haematopoietic myeloid cell lineages, predominantly in the bone marrow, and are often caused by aberrant protein tyrosine kinase activity. The protein tyrosine phosphatase CD45 is a trans-membrane molecule expressed on all haemopoietic blood cells except that of platelets and red cells. CD45 regulates various cellular physiological processes including proliferation, apoptosis, and lymphocyte activation. However, its role in chemotherapy response is still unknown; therefore, the aim of this study was to investigate the role of CD45 in myeloid malignancies in terms of cellular growth, apoptosis, and response to chemotherapy. The expression of CD45 on myeloid leukaemia primary cells and cell lines was heterogeneous with HEL and OCI-AML3 cells showing the highest level. Inhibition of CD45 resulted in increased cellular sensitivity to cytarabine and ruxolitinib, the two main therapies for AML and MPN. Bioinformatics analysis identified genes whose expression was correlated with CD45 expression such as JAK2, ACTR2, THAP3 Serglycin, and PBX-1 genes, as well as licensed drugs (alendronate, allopurinol, and balsalazide), which could be repurposed as CD45 inhibitors which effectively increases sensitivity to cytarabine and ruxolitinib at low doses. Therefore, CD45 inhibition could be explored as a potential therapeutic partner for treatment of myeloid malignancies in combination with chemotherapy such as cytarabine especially for elderly patients and those showing chemotherapy resistance.
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Affiliation(s)
- Maryam Ahmed S Al Barashdi
- Patrick G Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, Northern Ireland, UK
| | - Ahlam Ali
- Patrick G Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, Northern Ireland, UK
| | - Mary Frances McMullin
- Haematology Department, C-Floor Tower Block, Belfast City Hospital, Belfast, Northern Ireland, UK
| | - Ken Mills
- Patrick G Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, Northern Ireland, UK.
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Temaj G, Chichiarelli S, Saha S, Telkoparan-Akillilar P, Nuhii N, Hadziselimovic R, Saso L. An intricate rewiring of cancer metabolism via alternative splicing. Biochem Pharmacol 2023; 217:115848. [PMID: 37813165 DOI: 10.1016/j.bcp.2023.115848] [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: 08/24/2023] [Revised: 10/05/2023] [Accepted: 10/05/2023] [Indexed: 10/11/2023]
Abstract
All human genes undergo alternative splicing leading to the diversity of the proteins. However, in some cases, abnormal regulation of alternative splicing can result in diseases that trigger defects in metabolism, reduced apoptosis, increased proliferation, and progression in almost all tumor types. Metabolic dysregulations and immune dysfunctions are crucial factors in cancer. In this respect, alternative splicing in tumors could be a potential target for therapeutic cancer strategies. Dysregulation of alternative splicing during mRNA maturation promotes carcinogenesis and drug resistance in many cancer types. Alternative splicing (changing the target mRNA 3'UTR binding site) can result in a protein with altered drug affinity, ultimately leading to drug resistance.. Here, we will highlight the function of various alternative splicing factors, how it regulates the reprogramming of cancer cell metabolism, and their contribution to tumor initiation and proliferation. Also, we will discuss emerging therapeutics for treating tumors via abnormal alternative splicing. Finally, we will discuss the challenges associated with these therapeutic strategies for clinical applications.
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Affiliation(s)
- Gazmend Temaj
- Faculty of Pharmacy, College UBT, 10000 Prishtina, Kosovo
| | - Silvia Chichiarelli
- Department of Biochemical Sciences "A. Rossi-Fanelli", Sapienza University of Rome, 00185 Rome, Italy.
| | - Sarmistha Saha
- Department of Biotechnology, GLA University, Mathura 00185, Uttar Pradesh, India
| | | | - Nexhibe Nuhii
- Department of Pharmacy, Faculty of Medical Sciences, State University of Tetovo, 1200 Tetovo, Macedonia
| | - Rifat Hadziselimovic
- Faculty of Science, University of Sarajevo, 71000 Sarajevo, Bosnia and Herzegovina
| | - Luciano Saso
- Department of Physiology and Pharmacology "Vittorio Erspamer", La Sapienza University, 00185 Rome, Italy.
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4
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Impact of alternative splicing on mechanisms of resistance to anticancer drugs. Biochem Pharmacol 2021; 193:114810. [PMID: 34673012 DOI: 10.1016/j.bcp.2021.114810] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 10/05/2021] [Accepted: 10/06/2021] [Indexed: 12/15/2022]
Abstract
A shared characteristic of many tumors is the lack of response to anticancer drugs. Multiple mechanisms of pharmacoresistance (MPRs) are involved in permitting cancer cells to overcome the effect of these agents. Pharmacoresistance can be primary (intrinsic) or secondary (acquired), i.e., triggered or enhanced in response to the treatment. Moreover, MPRs usually result in the lack of sensitivity to several agents, which accounts for diverse multidrug-resistant (MDR) phenotypes. MPRs are based on the dynamic expression of more than one hundred genes, constituting the so-called resistome. Alternative splicing (AS) during pre-mRNA maturation results in changes affecting proteins involved in the resistome. The resulting splicing variants (SVs) reduce the efficacy of anticancer drugs by lowering the intracellular levels of active agents, altering molecular targets, enhancing both DNA repair ability and defensive mechanism of tumors, inducing changes in the balance between pro-survival and pro-apoptosis signals, modifying interactions with the tumor microenvironment, and favoring malignant phenotypic transitions. Reasons accounting for cancer-associated aberrant splicing include mutations that create or disrupt splicing sites or splicing enhancers or silencers, abnormal expression of splicing factors, and impaired signaling pathways affecting the activity of the splicing machinery. Here we have reviewed the impact of AS on MPR in cancer cells.
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Mehterov N, Kazakova M, Sbirkov Y, Vladimirov B, Belev N, Yaneva G, Todorova K, Hayrabedyan S, Sarafian V. Alternative RNA Splicing-The Trojan Horse of Cancer Cells in Chemotherapy. Genes (Basel) 2021; 12:genes12071085. [PMID: 34356101 PMCID: PMC8306420 DOI: 10.3390/genes12071085] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 07/14/2021] [Accepted: 07/15/2021] [Indexed: 12/12/2022] Open
Abstract
Almost all transcribed human genes undergo alternative RNA splicing, which increases the diversity of the coding and non-coding cellular landscape. The resultant gene products might have distinctly different and, in some cases, even opposite functions. Therefore, the abnormal regulation of alternative splicing plays a crucial role in malignant transformation, development, and progression, a fact supported by the distinct splicing profiles identified in both healthy and tumor cells. Drug resistance, resulting in treatment failure, still remains a major challenge for current cancer therapy. Furthermore, tumor cells often take advantage of aberrant RNA splicing to overcome the toxicity of the administered chemotherapeutic agents. Thus, deciphering the alternative RNA splicing variants in tumor cells would provide opportunities for designing novel therapeutics combating cancer more efficiently. In the present review, we provide a comprehensive outline of the recent findings in alternative splicing in the most common neoplasms, including lung, breast, prostate, head and neck, glioma, colon, and blood malignancies. Molecular mechanisms developed by cancer cells to promote oncogenesis as well as to evade anticancer drug treatment and the subsequent chemotherapy failure are also discussed. Taken together, these findings offer novel opportunities for future studies and the development of targeted therapy for cancer-specific splicing variants.
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Affiliation(s)
- Nikolay Mehterov
- Department of Medical Biology, Medical University-Plovdiv, 4002 Plovdiv, Bulgaria; (N.M.); (M.K.); (Y.S.)
- Research Institute, Medical University-Plovdiv, 4002 Plovdiv, Bulgaria
| | - Maria Kazakova
- Department of Medical Biology, Medical University-Plovdiv, 4002 Plovdiv, Bulgaria; (N.M.); (M.K.); (Y.S.)
- Research Institute, Medical University-Plovdiv, 4002 Plovdiv, Bulgaria
| | - Yordan Sbirkov
- Department of Medical Biology, Medical University-Plovdiv, 4002 Plovdiv, Bulgaria; (N.M.); (M.K.); (Y.S.)
- Research Institute, Medical University-Plovdiv, 4002 Plovdiv, Bulgaria
| | - Boyan Vladimirov
- Department of Maxillofacial Surgery, Medical University-Plovdiv, 4002 Plovdiv, Bulgaria;
| | - Nikolay Belev
- Medical Simulation and Training Center, Medical University-Plovdiv, 4002 Plovdiv, Bulgaria;
| | - Galina Yaneva
- Department of Biology, Faculty of Pharmacy, Medical University of Varna, 9002 Varna, Bulgaria;
| | - Krassimira Todorova
- Laboratory of Reproductive OMICs Technologies, Institute of Biology and Immunology of Reproduction, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria; (K.T.); (S.H.)
| | - Soren Hayrabedyan
- Laboratory of Reproductive OMICs Technologies, Institute of Biology and Immunology of Reproduction, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria; (K.T.); (S.H.)
| | - Victoria Sarafian
- Department of Medical Biology, Medical University-Plovdiv, 4002 Plovdiv, Bulgaria; (N.M.); (M.K.); (Y.S.)
- Research Institute, Medical University-Plovdiv, 4002 Plovdiv, Bulgaria
- Correspondence: ; Tel.: +359-882-512-952
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Bankar A, Siriwardena TP, Rizoska B, Rydergård C, Kylefjord H, Rraklli V, Eneroth A, Pinho P, Norin S, Bylund J, Moses S, Bethell R, Kavanagh S, Maclean N, Gronda M, Wang X, Hurren R, Minden MD, Targett-Adams P, Schimmer AD, Albertella M. Novel L-nucleoside analogue, 5-fluorotroxacitabine, displays potent efficacy against acute myeloid leukemia. Haematologica 2021; 106:574-579. [PMID: 31857370 PMCID: PMC7849559 DOI: 10.3324/haematol.2019.226795] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 12/18/2019] [Indexed: 12/19/2022] Open
Affiliation(s)
- Aniket Bankar
- Princess Margaret Cancer Center, University Health Network, Ontario, Canada
| | | | | | | | | | | | | | | | | | | | | | | | - Simon Kavanagh
- Princess Margaret Cancer Center, University Health Network, Ontario, Canada
| | - Neil Maclean
- Princess Margaret Cancer Center, University Health Network, Ontario, Canada
| | - Marcela Gronda
- Princess Margaret Cancer Center, University Health Network, Ontario, Canada
| | - Xiaoming Wang
- Princess Margaret Cancer Center, University Health Network, Ontario, Canada
| | - Rose Hurren
- Princess Margaret Cancer Center, University Health Network, Ontario, Canada
| | - Mark D Minden
- Princess Margaret Cancer Center, University Health Network, Ontario, Canada
| | | | - Aaron D Schimmer
- Princess Margaret Cancer Center, University Health Network, Ontario, Canada
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Levin M, Stark M, Ofran Y, Assaraf YG. Deciphering molecular mechanisms underlying chemoresistance in relapsed AML patients: towards precision medicine overcoming drug resistance. Cancer Cell Int 2021; 21:53. [PMID: 33446189 PMCID: PMC7809753 DOI: 10.1186/s12935-021-01746-w] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 01/02/2021] [Indexed: 12/13/2022] Open
Abstract
Background Acute myeloid leukemia (AML) remains a devastating disease with a 5-year survival rate of less than 30%. AML treatment has undergone significant changes in recent years, incorporating novel targeted therapies along with improvements in allogeneic bone marrow transplantation techniques. However, the standard of care remains cytarabine and anthracyclines, and the primary hindrance towards curative treatment is the frequent emergence of intrinsic and acquired anticancer drug resistance. In this respect, patients presenting with chemoresistant AML face dismal prognosis even with most advanced therapies. Herein, we aimed to explore the potential implementation of the characterization of chemoresistance mechanisms in individual AML patients towards efficacious personalized medicine. Methods Towards the identification of tailored treatments for individual patients, we herein present the cases of relapsed AML patients, and compare them to patients displaying durable remissions following the same chemotherapeutic induction treatment. We quantified the expression levels of specific genes mediating drug transport and metabolism, nucleotide biosynthesis, and apoptosis, in order to decipher the molecular mechanisms underlying intrinsic and/or acquired chemoresistance modalities in relapsed patients. This was achieved by real-time PCR using patient cDNA, and could be readily implemented in the clinical setting. Results This analysis revealed pre-existing differences in gene expression levels between the relapsed patients and patients with lasting remissions, as well as drug-induced alterations at different relapse stages compared to diagnosis. Each of the relapsed patients displayed unique chemoresistance mechanisms following similar treatment protocols, which could have been missed in a large study aimed at identifying common drug resistance determinants. Conclusions Our findings emphasize the need for standardized evaluation of key drug transport and metabolism genes as an integral component of routine AML management, thereby allowing for the selection of treatments of choice for individual patients. This approach could facilitate the design of efficacious personalized treatment regimens, thereby reducing relapse rates of therapy refractory disease.
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Affiliation(s)
- May Levin
- The Fred Wyszkowski Cancer Research Laboratory, Dept. of Biology, Technion-Israel Institute of Technology, 3200003, Haifa, Israel
| | - Michal Stark
- The Fred Wyszkowski Cancer Research Laboratory, Dept. of Biology, Technion-Israel Institute of Technology, 3200003, Haifa, Israel
| | - Yishai Ofran
- Department of Hematology and Bone Marrow Transplantation, Rambam Health Care Campus, Haifa, Israel.
| | - Yehuda G Assaraf
- The Fred Wyszkowski Cancer Research Laboratory, Dept. of Biology, Technion-Israel Institute of Technology, 3200003, Haifa, Israel.
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Sciarrillo R, Wojtuszkiewicz A, Assaraf YG, Jansen G, Kaspers GJL, Giovannetti E, Cloos J. The role of alternative splicing in cancer: From oncogenesis to drug resistance. Drug Resist Updat 2020; 53:100728. [PMID: 33070093 DOI: 10.1016/j.drup.2020.100728] [Citation(s) in RCA: 110] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 09/17/2020] [Accepted: 09/21/2020] [Indexed: 12/15/2022]
Abstract
Alternative splicing is a tightly regulated process whereby non-coding sequences of pre-mRNA are removed and protein-coding segments are assembled in diverse combinations, ultimately giving rise to proteins with distinct or even opposing functions. In the past decade, whole genome/transcriptome sequencing studies revealed the high complexity of splicing regulation, which occurs co-transcriptionally and is influenced by chromatin status and mRNA modifications. Consequently, splicing profiles of both healthy and malignant cells display high diversity and alternative splicing was shown to be widely deregulated in multiple cancer types. In particular, mutations in pre-mRNA regulatory sequences, splicing regulators and chromatin modifiers, as well as differential expression of splicing factors are important contributors to cancer pathogenesis. It has become clear that these aberrations contribute to many facets of cancer, including oncogenic transformation, cancer progression, response to anticancer drug treatment as well as resistance to therapy. In this respect, alternative splicing was shown to perturb the expression a broad spectrum of relevant genes involved in drug uptake/metabolism (i.e. SLC29A1, dCK, FPGS, and TP), activation of nuclear receptor pathways (i.e. GR, AR), regulation of apoptosis (i.e. MCL1, BCL-X, and FAS) and modulation of response to immunotherapy (CD19). Furthermore, aberrant splicing constitutes an important source of novel cancer biomarkers and the spliceosome machinery represents an attractive target for a novel and rapidly expanding class of therapeutic agents. Small molecule inhibitors targeting SF3B1 or splice factor kinases were highly cytotoxic against a wide range of cancer models, including drug-resistant cells. Importantly, these effects are enhanced in specific cancer subsets, such as splicing factor-mutated and c-MYC-driven tumors. Furthermore, pre-clinical studies report synergistic effects of spliceosome modulators in combination with conventional antitumor agents. These strategies based on the use of low dose splicing modulators could shift the therapeutic window towards decreased toxicity in healthy tissues. Here we provide an extensive overview of the latest findings in the field of regulation of splicing in cancer, including molecular mechanisms by which cancer cells harness alternative splicing to drive oncogenesis and evade anticancer drug treatment as well as splicing-based vulnerabilities that can provide novel treatment opportunities. Furthermore, we discuss current challenges arising from genome-wide detection and prediction methods of aberrant splicing, as well as unravelling functional relevance of the plethora of cancer-related splicing alterations.
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Affiliation(s)
- Rocco Sciarrillo
- Department of Hematology, Amsterdam UMC, VU University Medical Center, Cancer Center Amsterdam, Amsterdam, Netherlands; Department of Pediatric Oncology, Emma's Children's Hospital, Amsterdam UMC, VU University Medical Center, Cancer Center Amsterdam, Amsterdam, Netherlands; Department of Medical Oncology, Amsterdam UMC, VU University Medical Center, Cancer Center Amsterdam, Amsterdam, Netherlands
| | - Anna Wojtuszkiewicz
- Department of Hematology, Amsterdam UMC, VU University Medical Center, Cancer Center Amsterdam, Amsterdam, Netherlands
| | - Yehuda G Assaraf
- The Fred Wyszkowski Cancer Research Laboratory, Department of Biology, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Gerrit Jansen
- Amsterdam Immunology and Rheumatology Center, Amsterdam UMC, VU University Medical Center, Cancer Center Amsterdam, Amsterdam, Netherlands
| | - Gertjan J L Kaspers
- Department of Pediatric Oncology, Emma's Children's Hospital, Amsterdam UMC, VU University Medical Center, Cancer Center Amsterdam, Amsterdam, Netherlands; Princess Máxima Center for Pediatric Oncology, Utrecht, Netherlands
| | - Elisa Giovannetti
- Department of Medical Oncology, Amsterdam UMC, VU University Medical Center, Cancer Center Amsterdam, Amsterdam, Netherlands; Fondazione Pisana per la Scienza, Pisa, Italy
| | - Jacqueline Cloos
- Department of Hematology, Amsterdam UMC, VU University Medical Center, Cancer Center Amsterdam, Amsterdam, Netherlands.
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Chen XX, Zhu JH, Li ZP, Xiao HT, Zhou H. Comprehensive Characterization of the Prognosis Value of Alternative Splicing Events in Acute Myeloid Leukemia. DNA Cell Biol 2020; 39:1243-1255. [PMID: 32543226 DOI: 10.1089/dna.2020.5534] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Increasing evidence have demonstrated that dysregulated alternative splicing (AS) events promoted tumor development and was correlated with worse prognosis in the context of certain malignancies. Nevertheless, a comprehensive examination of the prognosis role of AS events in acute myeloid leukemia (AML) has not yet been illuminated. In this study, univariate and multivariate Cox regression analysis were used to identify survival-related AS events and independent prognostic predictors. The interaction between splicing factors (SFs) and AS events was visualized by Cytoscape. A total of 3013 survival-associated AS events in 1977 genes were screened in 151 AML patients. Interestingly, the majority (2031 events) were revealed to be protective factors. Furthermore, the prediction models were constructed for each type of AS and all of them displayed good performance in predicting prognosis, considering their area under curve values of the receiver operating characteristic were all above 0.7. Notably, the splicing regulatory network displayed the underlying interaction networks between SFs and AS events. Taken together, our study demonstrated the survival-related AS events in AML and uncovered the possible association between SFs and prognostic AS events, which provide new prognostic biomarkers and aid to develop novel targets for AML therapy.
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Affiliation(s)
- Xue-Xing Chen
- Institute of Hematology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jian-Hua Zhu
- Laboratory of Clinical Immunology, Wuhan No. 1 Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Zi-Ping Li
- Institute of Hematology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Hai-Tao Xiao
- Department of Anatomy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Hao Zhou
- Institute of Hematology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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10
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Levin M, Stark M, Berman B, Assaraf YG. Surmounting Cytarabine-resistance in acute myeloblastic leukemia cells and specimens with a synergistic combination of hydroxyurea and azidothymidine. Cell Death Dis 2019; 10:390. [PMID: 31101804 PMCID: PMC6525253 DOI: 10.1038/s41419-019-1626-x] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 05/02/2019] [Accepted: 05/02/2019] [Indexed: 12/13/2022]
Abstract
Acute myeloid leukemia (AML) patients display dismal prognosis due to high prevalence of refractory and relapsed disease resulting from chemoresistance. Treatment protocols, primarily based on the anchor drug Cytarabine, remained chiefly unchanged in the past 50 years with no standardized salvage regimens. Herein we aimed at exploring potential pre-clinical treatment strategies to surmount Cytarabine resistance in human AML cells. We established Cytarabine-resistant sublines derived from human leukemia K562 and Kasumi cells, and characterized the expression of Cytarabine-related genes using real-time PCR and Western blot analyses to uncover the mechanisms underlying their Cytarabine resistance. This was followed by growth inhibition assays and isobologram analyses testing the sublines’ sensitivity to the clinically approved drugs hydroxyurea (HU) and azidothymidine (AZT), compared to their parental cells. All Cytarabine-resistant sublines lost deoxycytidine kinase (dCK) expression, rendering them refractory to Cytarabine. Loss of dCK function involved dCK gene deletions and/or a novel frameshift mutation leading to dCK transcript degradation via nonsense-mediated decay. Cytarabine-resistant sublines displayed hypersensitivity to HU and AZT compared to parental cells; HU and AZT combinations exhibited a marked synergistic growth inhibition effect on leukemic cells, which was intensified upon acquisition of Cytarabine-resistance. In contrast, HU and AZT combination showed an antagonistic effect in non-malignant cells. Finally, HU and AZT synergism was demonstrated on peripheral blood specimens from AML patients. These findings identify a promising HU and AZT combination for the possible future treatment of relapsed and refractory AML, while sparing normal tissues from untoward toxicity.
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Affiliation(s)
- May Levin
- The Fred Wyszkowski Cancer Research Laboratory, Department of Biology, Technion-Israel Institute of Technology, Haifa, Israel
| | - Michal Stark
- The Fred Wyszkowski Cancer Research Laboratory, Department of Biology, Technion-Israel Institute of Technology, Haifa, Israel
| | - Bluma Berman
- The Fred Wyszkowski Cancer Research Laboratory, Department of Biology, Technion-Israel Institute of Technology, Haifa, Israel
| | - Yehuda G Assaraf
- The Fred Wyszkowski Cancer Research Laboratory, Department of Biology, Technion-Israel Institute of Technology, Haifa, Israel.
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11
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Baker D, Pryce G, Herrod SS, Schmierer K. Potential mechanisms of action related to the efficacy and safety of cladribine. Mult Scler Relat Disord 2019; 30:176-186. [PMID: 30785074 DOI: 10.1016/j.msard.2019.02.018] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 02/09/2019] [Accepted: 02/12/2019] [Indexed: 12/31/2022]
Abstract
Oral cladribine is a novel treatment for relapsing multiple sclerosis (MS). This appears to be a semi-selective immune-reconstitution therapy that induces long-term therapy from short treatment cycles. It has a relatively good safety profile that currently does not require extensive monitoring associated with some continuous immunosuppressive and relatively non-selective immune reconstitution therapies. The efficacy and safety of cladribine relates to its particular physicochemical properties, the function of the lymphocyte subsets that are selectively targeted by the drug and the repopulation kinetics of these subsets. As such, there is marked and long-term depletion of memory B cell subsets, which probably relates to the therapeutic efficacy. This is also coupled with a more limited, but likewise long-term, depletion of CD4 T subsets. There is limited depletion of cells of the innate immune system and modest effects on CD8 and probably plasma cells, which provide immediate and durable protection from infection. Targeting of CD4 T regulatory cells, CD8 T suppressor cells and regulatory B cell subsets appears more limited as these populations recover rapidly and so repopulating pathogenic cells re-emerge into a regulatory environment. This appears to lead to re-establishment of immune-tolerance that produces long-term control of MS. Although this hypothesis contains a number of unknown details, it is based on knowledge about the biology of cladribine, basic immunology and the effects of other high-efficacy B and T cell depleting agents that exhibit stereotyped repopulation behaviours. These concepts are relatively simple to interrogate, and can be modified as new knowledge about the durability of disease control and safety with cladribine emerges.
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Affiliation(s)
- David Baker
- BartsMS, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London E1 2AT, United Kingdom.
| | - Gareth Pryce
- BartsMS, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London E1 2AT, United Kingdom
| | - Samuel S Herrod
- BartsMS, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London E1 2AT, United Kingdom
| | - Klaus Schmierer
- BartsMS, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London E1 2AT, United Kingdom; Clinical Board:Medicine (Neuroscience), The Royal London Hospital, Barts Health NHS Trust, London E1 1BB, United Kingdom
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Tsesmetzis N, Paulin CBJ, Rudd SG, Herold N. Nucleobase and Nucleoside Analogues: Resistance and Re-Sensitisation at the Level of Pharmacokinetics, Pharmacodynamics and Metabolism. Cancers (Basel) 2018; 10:cancers10070240. [PMID: 30041457 PMCID: PMC6071274 DOI: 10.3390/cancers10070240] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2018] [Revised: 07/18/2018] [Accepted: 07/20/2018] [Indexed: 02/07/2023] Open
Abstract
Antimetabolites, in particular nucleobase and nucleoside analogues, are cytotoxic drugs that, starting from the small field of paediatric oncology, in combination with other chemotherapeutics, have revolutionised clinical oncology and transformed cancer into a curable disease. However, even though combination chemotherapy, together with radiation, surgery and immunotherapy, can nowadays cure almost all types of cancer, we still fail to achieve this for a substantial proportion of patients. The understanding of differences in metabolism, pharmacokinetics, pharmacodynamics, and tumour biology between patients that can be cured and patients that cannot, builds the scientific basis for rational therapy improvements. Here, we summarise current knowledge of how tumour-specific and patient-specific factors can dictate resistance to nucleobase/nucleoside analogues, and which strategies of re-sensitisation exist. We revisit well-established hurdles to treatment efficacy, like the blood-brain barrier and reduced deoxycytidine kinase activity, but will also discuss the role of novel resistance factors, such as SAMHD1. A comprehensive appreciation of the complex mechanisms that underpin the failure of chemotherapy will hopefully inform future strategies of personalised medicine.
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Affiliation(s)
- Nikolaos Tsesmetzis
- Childhood Cancer Research Unit, Department of Women's and Children's Health, Karolinska Institutet, 171 77 Stockholm, Sweden.
| | - Cynthia B J Paulin
- Science for Life Laboratory, Department of Oncology-Pathology, Karolinska Institutet, 171 65 Stockholm, Sweden.
| | - Sean G Rudd
- Science for Life Laboratory, Department of Oncology-Pathology, Karolinska Institutet, 171 65 Stockholm, Sweden.
| | - Nikolas Herold
- Childhood Cancer Research Unit, Department of Women's and Children's Health, Karolinska Institutet, 171 77 Stockholm, Sweden.
- Paediatric Oncology, Theme of Children's and Women's Health, Karolinska University Hospital Solna, 171 76 Stockholm, Sweden.
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13
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Wong ACH, Rasko JEJ, Wong JJL. We skip to work: alternative splicing in normal and malignant myelopoiesis. Leukemia 2018; 32:1081-1093. [DOI: 10.1038/s41375-018-0021-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Revised: 11/14/2017] [Accepted: 12/22/2017] [Indexed: 12/15/2022]
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14
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Wang Y, Lamba JK. Retracted: Influence of genetic variants of IDH1, IDH2, TET2 and DNMT3A on cytarabine cytotoxicity in different populations. J Clin Pharm Ther 2017. [PMID: 29164635 DOI: 10.1111/jcpt.12653] [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: 08/09/2017] [Accepted: 10/28/2017] [Indexed: 12/24/2022]
Abstract
'Influence of genetic variants of IDH1, IDH2, TET2 and DNMT3A on cytarabine cytotoxicity in different populations' by Y. Wang & J. K. Lamba1 The above article from the Journal of Clinical Pharmacy and Therapeutics, published online on 21 November 2017 in Wiley Online Library (wileyonlinelibrary.com), has been retracted following discussions with the authors, the Journal Editors and John Wiley & Sons Ltd. The Retraction has been agreed as this paper was submitted under the joint names of Yan Wang, Jatinder K. Lamba and a third co-author. After acceptance of the paper, Dr Wang wrote to the EiC asking for the name of the third co-author to be dropped because of insufficient contribution. The EiC asked that the request be signed by all three authors. When this arrived, the paper was published online with only Dr Wang and Dr Lamba. However, Dr Lamba wrote to the EiC after publication indicating that she had not previously seen the manuscript and that there were co-authors missing. As it is clear that Dr Lamba's signature was forged, we cannot rely on the integrity of the report. The retraction is with the agreement of Dr Lamba but not of Dr Wang. REFERENCE 1. Wang Y, Lamba JK. Influence of genetic variants of IDH1, IDH2, TET2 and DNMT3A on cytarabine cytotoxicity in different populations. J Clin Pharm Ther. 2017;00:1-9. https://doi.org/10.1111/jcpt.12653.
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Affiliation(s)
- Y Wang
- Department of Pharmacy, Affiliated Hospital of Xuzhou Medical University, Jiangsu, China
- Department of Experimental and Clinical Pharmacology, University of Minnesota, Minneapolis, MN, USA
| | - J K Lamba
- Department of Experimental and Clinical Pharmacology, University of Minnesota, Minneapolis, MN, USA
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15
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Lee HW, Lee SH, Lee MG, Ahn SH, Chang HY, Han KH. The clinical implication of single nucleotide polymorphisms in deoxycytidine kinase in chronic hepatitis B patients treated with lamivudine. J Med Virol 2015; 88:820-7. [PMID: 26400223 DOI: 10.1002/jmv.24393] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/21/2015] [Indexed: 11/09/2022]
Abstract
Deoxycytidine kinase (dCK) is a critical enzyme involved in intracellular phosphorylation of lamivudine (LAM) to its active triphosphates. We conducted this study to determine dCK polymorphisms in Koreans and to evaluate whether the discovered single nucleotide polymorphisms (SNPs) were associated with treatment outcomes in chronic hepatitis B (CHB) patients treated with LAM. The full-length dCK gene was sequenced from 24 healthy volunteers and 24 patients with CHB. One hundred twenty-seven patients with CHB who were followed-up for at least 24 months after LAM treatment were enrolled. Virological response as determined by undetectable HBV DNA was defined as a good drug response. Primary non-response at 6 months and virological breakthrough within 12 months were defined as a poor drug response. Six novel dCK SNPs were found (-2052C/A, IVS3 - 46G/del, IVS4 + 40G/T, IVS5 + 39T/C, IVS5 - 72A/T, and 966-975T10/T11). In particular, two promoter SNPs, namely -360C/G and -201C/T, were in full linkage disequilibrium. These two SNPs had a higher allele frequency than previously reported in Caucasian, Japanese, and Chinese (26% vs. 2%, 13.1%, and 15.6%, respectively). There was no significant difference between treatment response groups in terms of the distributions of SNP genotypes or allele frequencies. However, there was significant difference in the allele frequency of -360G/-201T between HBeAg seroclearance group and HBeAg non-seroclearance group (P = 0.045). In conclusion, six novel dCK SNPs were discovered. Two promoter SNPs, namely -360C/G and -201C/T, were more frequent in Koreans than other populations. In particular, HBeAg-positive patients with the -360G/-201T haplotype may help HBeAg seroclearance in response to LAM therapy.
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Affiliation(s)
- Hyun Woong Lee
- Department of Internal Medicine, Chung Ang University College of Medicine, Seoul, Korea.,Liver Cirrhosis Clinical Research Center, Seoul, Korea
| | - Sung Hee Lee
- Department of Pharmacology, Yonsei University College of Medicine, Seoul, Korea
| | - Min Goo Lee
- Department of Pharmacology, Yonsei University College of Medicine, Seoul, Korea
| | - Sang Hoon Ahn
- Liver Cirrhosis Clinical Research Center, Seoul, Korea.,Department of Internal Medicine, Yonsei Institute of Gastroenterology, Yonsei University College of Medicine, Seoul, Korea
| | - Hye Young Chang
- Liver Cirrhosis Clinical Research Center, Seoul, Korea.,Department of Internal Medicine, Yonsei Institute of Gastroenterology, Yonsei University College of Medicine, Seoul, Korea
| | - Kwang-Hyub Han
- Liver Cirrhosis Clinical Research Center, Seoul, Korea.,Department of Internal Medicine, Yonsei Institute of Gastroenterology, Yonsei University College of Medicine, Seoul, Korea
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16
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Wojtuszkiewicz A, Assaraf YG, Maas MJP, Kaspers GJL, Jansen G, Cloos J. Pre-mRNA splicing in cancer: the relevance in oncogenesis, treatment and drug resistance. Expert Opin Drug Metab Toxicol 2014; 11:673-89. [PMID: 25495223 DOI: 10.1517/17425255.2015.993316] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
INTRODUCTION Aberrant pre-mRNA splicing in cancer is emerging as an important determinant of oncogenesis, response to treatment and anticancer drug resistance. At the same time, the spliceosome has become a target for a novel class of pre-clinical chemotherapeutics with a potential future application in cancer treatment. Taken together, these findings offer novel opportunities for the enhancement of the efficacy of cancer therapy. AREAS COVERED This review presents a comprehensive overview of the molecular mechanisms involved in splicing and current developments regarding splicing aberrations in relation to several aspects of cancer formation and therapy. Identified mutations in the various components of the spliceosome and their implications for cancer prognosis are delineated. Moreover, the contribution of abnormal splicing patterns as well as deregulated splicing factors to chemoresistance is discussed, along with novel splicing-based therapeutic approaches. EXPERT OPINION Significant progress has been made in deciphering the role of splicing factors in cancer including carcinogenesis and drug resistance. Splicing-based prognostic tools as well as therapeutic options hold great potential towards improvements in cancer therapy. However, gaining more in-depth molecular insight into the consequences of mutations in various components of the splicing machinery as well as of cellular effects of spliceosome inhibition is a prerequisite to establish the role of splicing in tumor progression and treatment options, respectively.
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Affiliation(s)
- Anna Wojtuszkiewicz
- VU University Medical Center, Department of Pediatric Oncology/Hematology , Amsterdam , The Netherlands
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17
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Wan H, Zhu J, Chen F, Xiao F, Huang H, Han X, Zhong L, Zhong H, Xu L, Ni B, Zhong J. SLC29A1 single nucleotide polymorphisms as independent prognostic predictors for survival of patients with acute myeloid leukemia: an in vitro study. JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH : CR 2014; 33:90. [PMID: 25398670 PMCID: PMC4234887 DOI: 10.1186/s13046-014-0090-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Accepted: 10/20/2014] [Indexed: 12/12/2022]
Abstract
Background The mechanism behind poor survival of acute myeloid leukemia (AML) patients with 1-barabinofuranosylcytosine (Ara-C) based treatment remains unclear. This study aimed to assess the pharmacogenomic effects of Ara-C metabolic pathway in patients with AML. Methods The genotypes of 19 single nucleotide polymorphisms (SNPs) of DCK, CDA and SLC29A1from 100 AML patients treated with Ara-C were examined. All the SNPs were screened with ligase detection reaction assay. The transcription analysis of genes was examined by quantitative real time polymerase chain reaction. The association between clinical outcome and gene variants was evaluated by Kaplan-Meier method. Results Genotypes of rs9394992 and rs324148 for SLC29A1 in remission patients were significantly different from those in relapsed ones. Post-induction overall survival (OS) significantly decreased in patients with the CC genotype of rs324148 compared with CT and TT genotypes (hazard ratio [HR] = 2.997 [95% confidence interval (CI): 1.71-5.27]). As compared with CT and TT genotype, patients with the CC genotype of rs9394992 had longer survival time (HR = 0.25 [95% CI: 0.075-0.81]; HR = 0.43 [95% CI: 0.24-0.78]) and longer disease-free survival (DFS) (HR = 0.52 [95% CI: 0.29-0.93]; HR = 0.15 [95% CI: 0.05-0.47]) as well As compared with CT and TT genotype, patients with the CC genotype of rs324148 had shorter DFS (HR = 3.18 [95% CI: 1.76-5.76]). Additionally, patients with adverse karyotypes had shorter DFS (HR = 0.17 [95% CI: 0.05-0.54]) and OS (HR = 0.18 [95% CI: 0.05-0.68]). Conclusions AML patients with low activity of SLC29A1 genotype have shorter DFS and OS in Ara-C based therapy. Genotypes of rs9394992 and rs324148 may be independent prognostic predictors for the survival of AML patients. Electronic supplementary material The online version of this article (doi:10.1186/s13046-014-0090-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Haixia Wan
- Department of Hematology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, 160 Pujian Road, Shanghai, 200127, China.
| | - Jianyi Zhu
- Department of Hematology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, 160 Pujian Road, Shanghai, 200127, China.
| | - Fangyuan Chen
- Department of Hematology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, 160 Pujian Road, Shanghai, 200127, China.
| | - Fei Xiao
- Department of Hematology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, 160 Pujian Road, Shanghai, 200127, China.
| | - Honghui Huang
- Department of Hematology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, 160 Pujian Road, Shanghai, 200127, China.
| | - Xiaofeng Han
- Department of Hematology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, 160 Pujian Road, Shanghai, 200127, China.
| | - Lu Zhong
- Department of Hematology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, 160 Pujian Road, Shanghai, 200127, China.
| | - Hua Zhong
- Department of Hematology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, 160 Pujian Road, Shanghai, 200127, China.
| | - Lan Xu
- Department of Hematology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, 160 Pujian Road, Shanghai, 200127, China.
| | - Beiwen Ni
- Department of Hematology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, 160 Pujian Road, Shanghai, 200127, China.
| | - Jihua Zhong
- Department of Hematology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, 160 Pujian Road, Shanghai, 200127, China.
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18
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Rathe SK, Moriarity BS, Stoltenberg CB, Kurata M, Aumann NK, Rahrmann EP, Bailey NJ, Melrose EG, Beckmann DA, Liska CR, Largaespada DA. Using RNA-seq and targeted nucleases to identify mechanisms of drug resistance in acute myeloid leukemia. Sci Rep 2014; 4:6048. [PMID: 25116387 PMCID: PMC4131221 DOI: 10.1038/srep06048] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Accepted: 07/23/2014] [Indexed: 12/28/2022] Open
Abstract
The evolution from microarrays to transcriptome deep-sequencing (RNA-seq) and from RNA interference to gene knockouts using Clustered Regularly Interspaced Short Palindromic Repeats (CRISPRs) and Transcription Activator-Like Effector Nucleases (TALENs) has provided a new experimental partnership for identifying and quantifying the effects of gene changes on drug resistance. Here we describe the results from deep-sequencing of RNA derived from two cytarabine (Ara-C) resistance acute myeloid leukemia (AML) cell lines, and present CRISPR and TALEN based methods for accomplishing complete gene knockout (KO) in AML cells. We found protein modifying loss-of-function mutations in Dck in both Ara-C resistant cell lines. CRISPR and TALEN-based KO of Dck dramatically increased the IC50 of Ara-C and introduction of a DCK overexpression vector into Dck KO clones resulted in a significant increase in Ara-C sensitivity. This effort demonstrates the power of using transcriptome analysis and CRISPR/TALEN-based KOs to identify and verify genes associated with drug resistance.
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Affiliation(s)
- Susan K Rathe
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA
| | - Branden S Moriarity
- 1] Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA [2] Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN, USA [3] Center for Genome Engineering, University of Minnesota, Minneapolis, MN, USA
| | | | - Morito Kurata
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA
| | - Natalie K Aumann
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA
| | - Eric P Rahrmann
- 1] Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA [2] Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN, USA [3] Center for Genome Engineering, University of Minnesota, Minneapolis, MN, USA
| | - Natashay J Bailey
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA
| | - Ellen G Melrose
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA
| | - Dominic A Beckmann
- 1] Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN, USA [2] Center for Genome Engineering, University of Minnesota, Minneapolis, MN, USA
| | - Chase R Liska
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA
| | - David A Largaespada
- 1] Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA [2] Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN, USA [3] Center for Genome Engineering, University of Minnesota, Minneapolis, MN, USA [4] Brain Tumor Program, University of Minnesota, Minneapolis, MN, USA [5] Department of Pediatrics, University of Minnesota, Minneapolis, MN, USA
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19
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Expression of nucleoside-metabolizing enzymes in myelodysplastic syndromes and modulation of response to azacitidine. Leukemia 2013; 28:621-8. [PMID: 24192812 PMCID: PMC3948159 DOI: 10.1038/leu.2013.330] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Revised: 10/03/2013] [Accepted: 10/18/2013] [Indexed: 12/11/2022]
Abstract
The nucleoside analog azacitidine (AZA) is used in the treatment of myelodysplastic syndromes (MDS), but 30–40% of patients fail to respond or relapse after treatment. Hence, to identify new molecular alterations that allow for identification of patients unlikely to respond to AZA could impact the utility of this therapy. We determined the expression levels of genes involved in AZA metabolism: UCK1, UCK2, DCK, hENT1, RRM1 and RRM2 using quantitative PCR in samples from 57 patients with MDS who received AZA. Lower expression of UCK1 was seen in patients without a response to AZA (median 0.2 vs 0.49 for patients with response to AZA, P=0.07). This difference in UCK1 expression was not influenced by aberrant methylation of the UCK1 promoter. In addition, the seven polymorphic loci found in the coding sequence were not associated with UCK1 gene expression nor AZA response. Silencing of UCK1 by siRNA leads to blunted response to AZA in vitro. The univariate analysis revealed that patients expressing lower than median levels of UCK1 had a shorter overall survival (P=0.049). Our results suggest that expression level of UCK1 is correlated with clinical outcome and may influence the clinical response to AZA treatment in patients with MDS.
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20
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Abstract
Pre-messenger RNA splicing is significantly changed in cancer cells leading to the expression of cancer-specific transcripts. These transcripts have the potential to be used as cancer biomarkers and also as targets for new therapeutic approaches. In addition, the cancer-specific transcripts have the potential to alter the drug response of the cancer cells creating a chemo-resistant state. This later property of alternative splicing presents a challenge to clinicians in the design of effective therapeutic regimens. When a patient's cancer relapses it is frequently refractory to standard chemotherapies resulting in a poor clinical outcome. Therefore, understanding the mechanisms of how alternative splicing can lead to chemo-resistance is critical to the effective delivery of treatment. Here, we will discuss the impact of alternative splicing variants on drug metabolism and activation; on drug interactions with cell signaling pathways; and on cell death pathways in cancer therapeutics. In addition to the initial characterization of splicing variants, the mechanisms leading to alterations in splicing are being studied in the setting of chemo-resistance and will be discussed here. The promise of therapeutic intervention to obviate the impact of these splicing variants will significantly enhance treatment options for cancer patients.
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21
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Macanas-Pirard P, Leisewitz A, Broekhuizen R, Cautivo K, Barriga FM, Leisewitz F, Gidi V, Riquelme E, Montecinos VP, Swett P, Besa P, Ramirez P, Ocqueteau M, Kalergis AM, Holt M, Rettig M, DiPersio JF, Nervi B. Bone marrow stromal cells modulate mouse ENT1 activity and protect leukemia cells from cytarabine induced apoptosis. PLoS One 2012; 7:e37203. [PMID: 22629369 PMCID: PMC3358339 DOI: 10.1371/journal.pone.0037203] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2011] [Accepted: 04/16/2012] [Indexed: 01/05/2023] Open
Abstract
Background Despite a high response rate to chemotherapy, the majority of patients with acute myeloid leukemia (AML) are destined to relapse due to residual disease in the bone marrow (BM). The tumor microenvironment is increasingly being recognized as a critical factor in mediating cancer cell survival and drug resistance. In this study, we propose to identify mechanisms involved in the chemoprotection conferred by the BM stroma to leukemia cells. Methods Using a leukemia mouse model and a human leukemia cell line, we studied the interaction of leukemia cells with the BM microenvironment. We evaluated in vivo and in vitro leukemia cell chemoprotection to different cytotoxic agents mediated by the BM stroma. Leukemia cell apoptosis was assessed by flow cytometry and western blotting. The activity of the equilibrative nucleoside transporter 1 (ENT1), responsible for cytarabine cell incorporation, was investigated by measuring transport and intracellular accumulation of 3H-adenosine. Results Leukemia cell mobilization from the bone marrow into peripheral blood in vivo using a CXCR4 inhibitor induced chemo-sensitization of leukemia cells to cytarabine, which translated into a prolonged survival advantage in our mouse leukemia model. In vitro, the BM stromal cells secreted a soluble factor that mediated significant chemoprotection to leukemia cells from cytarabine induced apoptosis. Furthermore, the BM stromal cell supernatant induced a 50% reduction of the ENT1 activity in leukemia cells, reducing the incorporation of cytarabine. No protection was observed when radiation or other cytotoxic agents such as etoposide, cisplatin and 5-fluorouracil were used. Conclusion The BM stroma secretes a soluble factor that significantly protects leukemia cells from cytarabine-induced apoptosis and blocks ENT1 activity. Strategies that modify the chemo-protective effects mediated by the BM microenvironment may enhance the benefit of conventional chemotherapy for patients with AML.
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MESH Headings
- Animals
- Antimetabolites, Antineoplastic/pharmacology
- Antimetabolites, Antineoplastic/therapeutic use
- Apoptosis/drug effects
- Apoptosis/physiology
- Bone Marrow Cells/drug effects
- Bone Marrow Cells/metabolism
- Cell Line, Tumor
- Cell Proliferation/drug effects
- Cell Survival/drug effects
- Cytarabine/pharmacology
- Cytarabine/therapeutic use
- Equilibrative Nucleoside Transporter 1/metabolism
- Humans
- Leukemia, Myeloid, Acute/drug therapy
- Leukemia, Myeloid, Acute/metabolism
- Leukemia, Myeloid, Acute/pathology
- Mice
- Stromal Cells/drug effects
- Stromal Cells/metabolism
- Tumor Cells, Cultured
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Affiliation(s)
- Patricia Macanas-Pirard
- Departamento de Hematología y Oncología, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Andrea Leisewitz
- Departamento de Hematología y Oncología, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Richard Broekhuizen
- Departamento de Hematología y Oncología, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Kelly Cautivo
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Millennium Institute on Immunology and Immunotherapy, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Francisco M. Barriga
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Millennium Institute on Immunology and Immunotherapy, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Francisco Leisewitz
- Departamento de Hematología y Oncología, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Victoria Gidi
- Departamento de Hematología y Oncología, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Erick Riquelme
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Millennium Institute on Immunology and Immunotherapy, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Viviana P. Montecinos
- Departamento de Hematología y Oncología, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Pilar Swett
- Departamento de Hematología y Oncología, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Pelayo Besa
- Departamento de Hematología y Oncología, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Pablo Ramirez
- Departamento de Hematología y Oncología, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Mauricio Ocqueteau
- Departamento de Hematología y Oncología, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Alexis M. Kalergis
- Departamento de Reumatología, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Millennium Institute on Immunology and Immunotherapy, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Matthew Holt
- Oncology Division, Washington University School of Medicine, Saint Louis, Missouri, United States of America
| | - Michael Rettig
- Oncology Division, Washington University School of Medicine, Saint Louis, Missouri, United States of America
| | - John F. DiPersio
- Oncology Division, Washington University School of Medicine, Saint Louis, Missouri, United States of America
| | - Bruno Nervi
- Departamento de Hematología y Oncología, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
- * E-mail:
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22
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Saiki Y, Yoshino Y, Fujimura H, Manabe T, Kudo Y, Shimada M, Mano N, Nakano T, Lee Y, Shimizu S, Oba S, Fujiwara S, Shimizu H, Chen N, Nezhad ZK, Jin G, Fukushige S, Sunamura M, Ishida M, Motoi F, Egawa S, Unno M, Horii A. DCK is frequently inactivated in acquired gemcitabine-resistant human cancer cells. Biochem Biophys Res Commun 2012; 421:98-104. [PMID: 22490663 DOI: 10.1016/j.bbrc.2012.03.122] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2012] [Accepted: 03/27/2012] [Indexed: 12/11/2022]
Abstract
Although gemcitabine is the most effective chemotherapeutic agent against pancreatic cancer, a growing concern is that a substantial number of patients acquire gemcitabine chemoresistance. To elucidate the mechanisms of acquisition of gemcitabine resistance, we developed gemcitabine-resistant cell lines from six human cancer cell lines; three pancreatic, one gastric, one colon, and one bile duct cancer. We first analyzed gemcitabine uptake using three paired parental and gemcitabine resistant pancreatic cancer cell lines (PK-1 and RPK-1, PK-9 and RPK-9, PK-59 and RPK-59) and found that uptake of gemcitabine was rapid. However, no DNA damage was induced in resistant cells. We further examined the microarray-based expression profiles of the cells to identify genes associated with gemcitabine resistance and found a remarkable reduction in the expression of deoxycytidine kinase (DCK). DCK is a key enzyme that activates gemcitabine by phosphorylation. Genetic alterations and expression of DCK were studied in these paired parental and derived gemcitabine-resistant cell lines, and inactivating mutations were found only in gemcitabine-resistant cell lines. Furthermore, siRNA-mediated knockdown of DCK in the parental cell lines yielded gemcitabine resistance, and introduction of DCK into gemcitabine-resistant cell lines invariably restored gemcitabine sensitivities. Mutation analyses were expanded to three other different paired cell lines, DLD-1 and RDLD-1 (colon cancer cell line), MKN-28 and RMKN-28 (gastric cancer cell line), and TFK-1 and RTFK -1 (cholangiocarcinoma cell line). We found inactivating mutations in RDLD-1 and RTFK-1 and decreased expression of DCK in RMKN-28. These results indicate that the inactivation of DCK is one of the crucial mechanisms in acquisition of gemcitabine resistance.
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Affiliation(s)
- Yuriko Saiki
- Department of Molecular Pathology, Tohoku University Graduate School of Medicine, Sendai, Japan
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Rivero A, Rapado I, Tomás JF, Montalbán C, de Oña R, Paz-Carreira J, Canales M, Martínez R, Sánchez-Godoy P, de Sevilla AF, de la Serna J, Martínez-López J. Relationship between deoxycytidine kinase (DCK) genotypic variants and fludarabine toxicity in patients with follicular lymphoma. Leuk Res 2011; 35:431-7. [DOI: 10.1016/j.leukres.2010.09.026] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2010] [Revised: 09/23/2010] [Accepted: 09/29/2010] [Indexed: 02/02/2023]
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24
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Burke AC, Swords RT, Kelly K, Giles FJ. Current status of agents active against the T315I chronic myeloid leukemia phenotype. Expert Opin Emerg Drugs 2011; 16:85-103. [DOI: 10.1517/14728214.2011.531698] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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25
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Rathe SK, Largaespada DA. Deoxycytidine kinase is downregulated in Ara-C-resistant acute myeloid leukemia murine cell lines. Leukemia 2010; 24:1513-5. [PMID: 20508618 DOI: 10.1038/leu.2010.88] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Danesi R, Altavilla G, Giovannetti E, Rosell R. Pharmacogenomics of gemcitabine in non-small-cell lung cancer and other solid tumors. Pharmacogenomics 2009; 10:69-80. [PMID: 19102717 DOI: 10.2217/14622416.10.1.69] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The validation of predictive biomarkers to tailor chemotherapy is a key issue in the development of effective treatment modalities against cancer. Examples of how genetics might affect drug response are offered by gemcitabine. A substantial number of potential biomarkers for sensitivity or resistance to gemcitabine have been proposed, including ribonucleotide reductase and cytidine deaminase polymorphisms, human equilibrative transporter-1 and ribonucleotide reductase gene-expression and AKT phosphorylation status. These markers displayed a significant relationship with disease response to the drug; however, their robustness needs to be evaluated within prospective studies. Moreover, recent trials of customized chemotherapy based on genetic markers have been carried out in non-small-cell lung cancer and promising pharmacogenetic determinants are gaining momentum, including BRCA1 and ERCC1. Hopefully, biomarkers to select patients most likely to respond to gemcitabine will be validated in the near future.
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Affiliation(s)
- Romano Danesi
- Division of Pharmacology & Chemotherapy, Department of Internal Medicine, University of Pisa, Via Roma 55, 56126 Pisa, Italy.
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Population-specific genetic variants important in susceptibility to cytarabine arabinoside cytotoxicity. Blood 2008; 113:2145-53. [PMID: 19109566 DOI: 10.1182/blood-2008-05-154302] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cytarabine arabinoside (ara-C) is an antimetabolite used to treat hematologic malignancies. Resistance is a common reason for treatment failure with adverse side effects contributing to morbidity and mortality. Identification of genetic factors important in susceptibility to ara-C cytotoxicity may allow for individualization of treatment. We used an unbiased whole-genome approach using lymphoblastoid cell lines derived from persons of European (CEU) or African (YRI) ancestry to identify these genetic factors. We interrogated more than 2 million single nucleotide polymorphisms (SNPs) for association with susceptibility to ara-C and narrowed our focus by concentrating on SNPs that affected gene expression. We identified a unique pharmacogenetic signature consisting of 4 SNPs explaining 51% of the variability in sensitivity to ara-C among the CEU and 5 SNPs explaining 58% of the variation among the YRI. Population-specific signatures were secondary to either (1) polymorphic SNPs in one population but monomorphic in the other, or (2) significant associations of SNPs with cytotoxicity or gene expression in one population but not the other. We validated the gene expression-cytotoxicity relationship for a subset of genes in a separate group of lymphoblastoid cell lines. These unique genetic signatures comprise novel genes that can now be studied further in functional studies.
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Smal C, Van Den Neste E, Maerevoet M, Poiré X, Théate I, Bontemps F. Positive regulation of deoxycytidine kinase activity by phosphorylation of Ser-74 in B-cell chronic lymphocytic leukaemia lymphocytes. Cancer Lett 2007; 253:68-73. [PMID: 17350163 DOI: 10.1016/j.canlet.2007.01.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2006] [Accepted: 01/15/2007] [Indexed: 11/22/2022]
Abstract
Deoxycytidine kinase (dCK) activates several antileukaemic nucleoside analogues. We have recently reported that the activity of dCK, overexpressed in HEK 293T cells, correlates with its phosphorylation level on Ser-74. Here, we show that dCK from B-cell chronic lymphocytic leukaemia (B-CLL) lymphocytes can be detected by an anti-phospho-Ser-74 antibody and that interindividual variability in dCK activity is related to its phosphorylation level on Ser-74. Moreover, pharmacological intervention modified Ser-74 phosphorylation, in close parallel with changes in dCK activity. These results suggest that activation of dCK via phosphorylation of Ser-74 might constitute a new therapeutic strategy to enhance activation and efficacy of nucleoside analogues.
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Affiliation(s)
- Caroline Smal
- Laboratory of Physiological Chemistry, Christian de Duve Institute of Cellular Pathology and Université catholique de Louvain, B-1200 Brussels, Belgium
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29
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Szantai E, Ronai Z, Sasvari-Szekely M, Bonn G, Guttman A. Multicapillary Electrophoresis Analysis of Single-Nucleotide Sequence Variations in the Deoxycytidine Kinase Gene. Clin Chem 2006; 52:1756-62. [PMID: 16858072 DOI: 10.1373/clinchem.2006.071159] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Abstract
Background: Investigation of the genetic background of complex traits is the focus of recent interest, as several common diseases or the individual response to treatments of various illnesses have not yet been explored. These studies require the development and implementation of reliable and large-scale genotyping methods. In this report, we introduce an efficient technique based on PCR–restriction fragment length sequence variation technique for the analysis of the −360CG and −201CT single-nucleotide sequence variations in the deoxycytidine kinase gene.
Methods: A multicapillary gel electrophoresis instrument was used for the size determination of the generated DNA fragments. A healthy Hungarian population of 100 individuals was investigated to determine allele and genotype frequencies for the 2 sequence variations of interest.
Results: We found that the occurrence of the minor allele is rather low, i.e., the frequency of both the −360G and −201T variants is 1%.
Conclusions: Our technique can readily facilitate the analysis of these important sequence variations in other ethnic groups to clarify the role of these sequence variations in conjunction with arabinosylcytosine treatment in acute myeloid leukemia.
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Affiliation(s)
- Eszter Szantai
- Horváth Laboratory of Bioseparation Sciences and Institute of Analytical Chemistry and Radiochemistry, Institute of Analytical Chemistry and Radiochemistry, Leopold-Franzens University, Innsbruck, Austria
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30
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Lotfi K, Karlsson K, Fyrberg A, Juliusson G, Jonsson V, Peterson C, Eriksson S, Albertioni F. The pattern of deoxycytidine- and deoxyguanosine kinase activity in relation to messenger RNA expression in blood cells from untreated patients with B-cell chronic lymphocytic leukemia. Biochem Pharmacol 2006; 71:882-90. [PMID: 16436271 DOI: 10.1016/j.bcp.2005.12.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2005] [Revised: 12/07/2005] [Accepted: 12/07/2005] [Indexed: 11/26/2022]
Abstract
Deoxycytidine kinase (dCK) and deoxyguanosine kinase (dGK) catalyze the first step in the intracellular cascade of fludarabine (2-fluoroadenine-beta-D-arabinofuranoside) and cladribine (2-chlorodeoxyadenosine) phosphorylation, which leads to activation of these prodrugs, commonly used for treatment of chronic lymphocytic leukemia (CLL). Thus, resistance to nucleoside analogues may primarily be due to low levels of deoxynucleoside kinase activity. The purpose of this study was to investigate the activity profiles of dCK and dGK and characterize the possible relationship between the levels of dCK enzymatic activities and mRNA levels in B-CLL cells from untreated patient samples in an attempt to determine the best approach for predicting sensitivity to nucleoside analogues and thereby optimizing treatment of CLL. For this purpose, dCK and dGK analyses were done in blood cells from 59 untreated symptomatic patients with CLL. The dGK activity towards 2-chlorodeoxyadenosine was significantly lower than of dCK (median 73 pmol/mg protein/min (85-121, 95% CI) versus 353 pmol/mg protein/min (331-421)). The median dCK mRNA level was 0.107 (0.096-0.120, 95% CI). There was a lack of correlation between the activities of dCK and dGK, which indicates that these proteins are regulated independently. We also found that the dCK and dGK activity measurement towards their endogenous substrates were comparable to the nucleoside analogues tested. Such variations in enzyme activities and mRNA levels may well explain differences in clinical responses to treatment. There was no correlation between the levels of dCK mRNAs and enzymatic activities using a quantitative real-time PCR procedure. Sequencing of dCK mRNA did not reveal alternate splicing or mutations in the coding region. The relation between activity and mRNA levels was studied by short interfering RNA (siRNA) method, which showed that in the siRNA treated cells the down-regulation of dCK expression, and activity followed each other. However, in control cells the mRNA levels remained stable but the protein activity markedly decreased. These data demonstrate that the dCK activity is not reflected by dCK mRNA expression that indicates a post-translational mechanism(s).
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Affiliation(s)
- Kourosh Lotfi
- Department of Medicine and Care, Clinical Pharmacology, Faculty of Health Sciences, Linköping University, Linköping, Sweden.
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Löfgren C, Albertioni F, Paul C. High activity and incomplete cross resistance of nucleoside analogues cladribine and fludarabine versus Ara-C on leukemic cells from patients with AML. Ther Drug Monit 2006; 27:641-6. [PMID: 16175139 DOI: 10.1097/01.ftd.0000175157.94192.dc] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The in vitro activity and cross-resistance pattern of the purine analogues cladribine and fludarabine and the pyrimidine analogue cytarabine on leukemic cells from 170 patients with AML was evaluated using a bioluminescence assay. In in vivo mimicking concentrations, cladribine (50 nmol/L) and fludarabine (2 micromol/L) were more cytotoxic than cytarabine (0.5 micromol/L). The cytotoxic effect of fludarabine correlated weakly to cytarabine (r = 0.37, P < 0.001). The cytotoxic effect of cladribine correlated better to cytarabine (r = 0.49, P = 0.0002) but best to fludarabine (r = 0.82, P < 0.001). There was an absence of correlation between either cladribine or fludarabine and daunorubicin (0.2 micromol/L). Of 45 highly Ara-C-resistant samples, cladribine exerted high or intermediate effect in 54% and fludarabine in 52%. These in vitro data indicate that cladribine and fludarabine are active drugs in the treatment of AML. The cross resistance to cytarabine was not complete, and the drugs can be valuable either as alternatives to Ara-C or in combination therapy for treatment of leukemia resistant to standard therapy.
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Affiliation(s)
- C Löfgren
- Department of Clinical Hematology, Karolinska University Hospital, Stockholm, Sweden.
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32
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Smal C, Vertommen D, Bertrand L, Ntamashimikiro S, Rider MH, Van Den Neste E, Bontemps F. Identification of in vivo phosphorylation sites on human deoxycytidine kinase. Role of Ser-74 in the control of enzyme activity. J Biol Chem 2005; 281:4887-93. [PMID: 16361699 DOI: 10.1074/jbc.m512129200] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Deoxycytidine kinase (dCK) catalyzes the rate-limiting step of the deoxyribonucleoside salvage pathway in mammalian cells and plays a key role in the activation of numerous nucleoside analogues used in anti-cancer and antiviral chemotherapy. Although compelling evidence indicated that dCK activity might be regulated by phosphorylation/dephosphorylation, direct demonstration was lacking. Here we showed that dCK overexpressed in HEK 293T cells was labeled after incubating the cells with [32P]orthophosphate. Sorbitol, which was reported to decrease dCK activity, also decreased the labeling of dCK. These results indicated that dCK may exist as a phosphoprotein in vivo and that its activity can be correlated with its phosphorylation level. After purification of 32P-labeled dCK, digestion by trypsin, and analysis of the radioactive peptides by tandem mass spectrometry, the following four in vivo phosphorylation sites were identified: Thr-3, Ser-11, Ser-15, and Ser-74, the latter being the major phosphorylation site. Site-directed mutagenesis and use of an anti-phospho-Ser-74 antibody demonstrated that Ser-74 phosphorylation was crucial for dCK activity in HEK 293T cells, whereas phosphorylation of other identified sites did not seem essential. Phosphorylation of Ser-74 was also detected on endogenous dCK in leukemic cells, in which the Ser-74 phosphorylation state was increased by agents that enhanced dCK activity. Our study provided direct evidence that dCK activity can be controlled by phosphorylation in intact cells and highlights the importance of Ser-74 for dCK activity.
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Affiliation(s)
- Caroline Smal
- Laboratory of Physiological Chemistry and Hormone and Metabolic Research Unit, Christian de Duve Institute of Cellular Pathology, Brussels, Belgium
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Maring JG, Groen HJM, Wachters FM, Uges DRA, de Vries EGE. Genetic factors influencing pyrimidine-antagonist chemotherapy. THE PHARMACOGENOMICS JOURNAL 2005; 5:226-43. [PMID: 16041392 DOI: 10.1038/sj.tpj.6500320] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Pyrimidine antagonists, for example, 5-fluorouracil (5-FU), cytarabine (ara-C) and gemcitabine (dFdC), are widely used in chemotherapy regimes for colorectal, breast, head and neck, non-small-cell lung cancer, pancreatic cancer and leukaemias. Extensive metabolism is a prerequisite for conversion of these pyrimidine prodrugs into active compounds. Interindividual variation in the activity of metabolising enzymes can affect the extent of prodrug activation and, as a result, act on the efficacy of chemotherapy treatment. Genetic factors at least partly explain interindividual variation in antitumour efficacy and toxicity of pyrimidine antagonists. In this review, proteins relevant for the efficacy and toxicity of pyrimidine antagonists will be summarised. In addition, the role of germline polymorphisms, tumour-specific somatic mutations and protein expression levels in the metabolic pathways and clinical pharmacology of these drugs are described. Germline polymorphisms of uridine monophosphate kinase (UMPK), orotate phosphoribosyl transferase (OPRT), thymidylate synthase (TS), dihydropyrimidine dehydrogenase (DPD) and methylene tetrahydrofolate reductase (MTHFR) and gene expression levels of OPRT, UMPK, TS, DPD, uridine phosphorylase, uridine kinase, thymidine phosphorylase, thymidine kinase, deoxyuridine triphosphate nucleotide hydrolase are discussed in relation to 5-FU efficacy. Cytidine deaminase (CDD) and 5'-nucleotidase (5NT) gene polymorphisms and CDD, 5NT, deoxycytidine kinase and MRP5 gene expression levels and their potential relation to dFdC and ara-C cytotoxicity are reviewed.
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Affiliation(s)
- J G Maring
- Department of Pharmacy, Diaconessen Hospital Meppel & Bethesda Hospital Hoogeveen, Meppel, The Netherlands.
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Ogawa M, Hori H, Ohta T, Onozato K, Miyahara M, Komada Y. Sensitivity to gemcitabine and its metabolizing enzymes in neuroblastoma. Clin Cancer Res 2005; 11:3485-93. [PMID: 15867251 DOI: 10.1158/1078-0432.ccr-04-1781] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE We examined the activity of gemcitabine against neuroblastoma in vitro and in vivo. In addition, we investigated the cellular mechanisms of high sensitivity to the agent in neuroblastoma cells. EXPERIMENTAL DESIGN We examined 11 neuroblastoma cell lines for sensitivity to gemcitabine and other chemotherapeutic agents used clinically for neuroblastoma. The in vivo sensitivity of neuroblastoma to gemcitabine was determined in xenograft models. Furthermore, the major metabolic enzymes of gemcitabine were assessed and compared in leukemia and carcinoma cells. Apoptosis and mitochondrial membrane potentials were also evaluated. RESULTS The IC50s for gemcitabine in 11 neuroblastoma lines ranged between 3 nmol/L and 4 micromol/L. The high activity of gemcitabine against neuroblastoma was confirmed in animal models. Interestingly, enzymes in neuroblastoma cells involved in the metabolism of deoxycytidine analogue have unique characteristics among solid tumors. The median of deoxycytidine kinase activity in neuroblastoma lines was similar to that in leukemia lines, which have low IC50s for cytarabine. Cytidine deaminase (CDA) activity in neuroblastoma was hardly detectable and significantly lower than that in carcinoma. The defect of CDA activity was associated with negative expression of mRNA. Furthermore, gemcitabine-induced apoptosis was observed irrespective of the caspase-8 status of neuroblastoma cells, which indicates that apoptosis depends on the mitochondrial pathway. CONCLUSIONS Neuroblastoma is highly sensitive to gemcitabine. Although the cellular mechanism involved in sensitivity to gemcitabine is multifactorial, low CDA activity may contribute high sensitivity in neuroblastoma cells. These results suggest that clinical application of gemcitabine to the treatment of neuroblastoma is warranted.
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Affiliation(s)
- Masahiro Ogawa
- Department of Pediatrics, Mie University School of Medicine, Tsu, Japan
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35
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Fernandez-Calotti P, Jordheim LP, Giordano M, Dumontet C, Galmarini CM. Substrate cycles and drug resistance to 1-beta-D-arabinofuranosylcytosine (araC). Leuk Lymphoma 2005; 46:335-46. [PMID: 15621823 DOI: 10.1080/10428190400015683] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Acute myelogenous leukemia (AML) is the most common form of acute leukemia in adults. After diagnosis, patients with AML are mainly treated with standard induction chemotherapy combining cytarabine (araC) and anthracyclines. The majority of them achieve complete remission (CR) (65-80%). However, prospects for long-term survival are poor for the majority of patients. Resistance to chemotherapy therefore remains a major obstacle in the effective treatment of patients with AML. In this review, we highlight the current knowledge of substrate cycles involved in normal deoxynucleoside triphosphate (dNTPs) metabolism and their possible role in drug resistance to araC.
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Affiliation(s)
- Paula Fernandez-Calotti
- Laboratorio de Immunología Oncológica-IIHEMA, Academia Nacional de Medicina, Buenos Aires, Argentina.
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Al-Madhoun AS, Talianidis I, Eriksson S. Transcriptional regulation of the mouse deoxycytidine kinase: identification and functional analysis of nuclear protein binding sites at the proximal promoter. Biochem Pharmacol 2005; 68:2397-407. [PMID: 15548386 DOI: 10.1016/j.bcp.2004.08.023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2004] [Accepted: 08/23/2004] [Indexed: 11/26/2022]
Abstract
Deoxycytidine kinase (EC 2.7.1.74, dCK) catalyzes the phosphorylation of deoxynucleosides and several nucleoside analogues that are important in antiviral and cancer chemotherapy. The enzyme is predominantly expressed in lymphoid tissue by as yet poorly defined mechanisms. In this work, we have studied the mouse dCK regulatory region to understand the molecular details of the tissue specific expression of the enzyme. DNase I footprinting and electrophoretic mobility shift assays using nuclear extracts from mouse lymphocytes (EL-4, T cells; J558, B cells) and non-lymphoid cells (L929, fibroblasts) demonstrated the existence of at least six cis-acting elements (FP-1-FP-6) within the proximal promoter region. Functional analysis revealed that all the elements necessary to promote high level transcription of the mdCK gene are located downstream the transcription start site. 5'-Deletion and site-directed mutagenesis assays demonstrated the importance of four GC-rich regions, which bind Sp-1 and Sp-3 transcription factors. In addition, we identified a site (FP-3) located at the -282 to -310 nucleotide region of the promoter, which binds NF-1, only in B cells. Analysis of point mutations introduced at the different regions revealed functional differences in their role in mdCK transcription in the cell lines used.
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Affiliation(s)
- Ashraf Said Al-Madhoun
- Division of Veterinary Medical Biochemistry, Department of Molecular Biosciences, The Biomedical Center, Swedish University of Agricultural Sciences, SE-75123 Uppsala, Sweden
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Shikama Y, Shichishima T, Matsuoka I, Jubinsky PT, Sieff CA, Maruyama Y. Accumulation of an intron-retained mRNA for granulocyte macrophage-colony stimulating factor receptor common beta chain in neutrophils of myelodysplastic syndromes. J Leukoc Biol 2005; 77:811-9. [PMID: 15728248 DOI: 10.1189/jlb.0904488] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
We recently identified a reduction in the neutrophil surface expression of common beta chain (beta c) of the receptor for granulocyte macrophage-colony stimulating factor (GM-CSF) in the patients with myelodysplastic syndromes (MDS). To determine the etiology of the impaired beta c expression, beta c mRNA from neutrophilic granulocytes of MDS patients and healthy controls was analyzed by a combination of direct reverse transcriptase-polymerase chain reaction-based single-strand conformational polymorphism and sequencing. Nine different beta c transcripts were detected, but none was specific for MDS. However, one of the transcripts (beta c79) containing a 79-base intron insertion between exons V and VI was significantly increased in MDS. This 27-kd isoform consisted of the beta c N-terminal 182 amino acids followed by a new 84-amino-acid sequence. beta c79 was overexpressed in all MDS subtypes. No genomic mutations were detected within the intron or at the intron/exon boundaries. The isoform is predominantly located in the cytoplasm by Western blot analysis and was unable to generate high-affinity binding sites or transduce a signal for proliferation when coexpressed with the receptor for human GM-CSF alpha chain. Our study suggests that the accumulation of the abnormal beta c transcripts with intron V retention results in the reduction in cell-surface expression of beta c observed in MDS.
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Affiliation(s)
- Yayoi Shikama
- Department of Pharmacology, Fukushima Medical University, Fukushima, 960-1295, Japan.
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38
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Shi JY, Shi ZZ, Zhang SJ, Zhu YM, Gu BW, Li G, Bai XT, Gao XD, Hu J, Jin W, Huang W, Chen Z, Chen SJ. Association between single nucleotide polymorphisms in deoxycytidine kinase and treatment response among acute myeloid leukaemia patients. ACTA ACUST UNITED AC 2004; 14:759-68. [PMID: 15564883 DOI: 10.1097/00008571-200411000-00007] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Development of resistance to 1-beta-arabinofuranosylcytosine (AraC) is a major obstacle in the treatment of patients with acute myeloid leukaemia (AML). Deficiency of functional deoxycytidine kinase (dCK) plays an important role in AraC resistance in vitro. We screened 5378 bp sequences of the dCK gene, including all exons and the 5' flanking region, and identified two single nucleotide polymorphisms (SNPs) in the regulatory region (rSNPs) with high allele frequencies. These two rSNPs (-201C>T and -360C>G) formed two major haplotypes. Genotyping with sequencing and MassARRAY system among 122 AML patients showed that those with -360CG/-201CT and -360GG/-201TT compound genotypes (n = 41) displayed a favourable response to chemotherapy whereas those with -360CC/-201CC (n = 81) tended to have a poor response (P = 0.025). Moreover, real-time quantitative reverse transcriptase-polymerase chain reaction showed that patients with -360CG/-201CT and -360GG/-201TT genotypes expressed higher level of dCK mRNA compared to those with the -360CC/-201CC genotype (P = 0.0034). Luciferase-reporter assay showed that dCK 5' regulatory region bearing -360G/-201T genotype alone had an eight-fold greater transcriptional activation activity compared to that with -360C/-201C genotype, whereas co-transfection of both -360G/-201T and -360C/-201C constructs mimicked the heterozygous genotype, which exhibited a four-fold greater activity compared to that with -360C/-201C. These results indicate that rSNP haplotypes of dCK gene may serve as a genetic marker for predicting drug responsiveness, which will be beneficial in establishing more effective AML chemotherapeutic regimens.
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Affiliation(s)
- Jing-Yi Shi
- State Key Laboratory of Medical Genomics Shanghai Institute of Hematology, Shanghai, PR China
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Al-Madhoun AS, van der Wilt CL, Loves WJP, Padron JM, Eriksson S, Talianidis I, Peters GJ. Detection of an alternatively spliced form of deoxycytidine kinase mRNA in the 2'-2'-difluorodeoxycytidine (gemcitabine)-resistant human ovarian cancer cell line AG6000. Biochem Pharmacol 2004; 68:601-9. [PMID: 15276067 DOI: 10.1016/j.bcp.2004.05.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2004] [Accepted: 05/06/2004] [Indexed: 02/07/2023]
Abstract
Gemcitabine (2'-2'-difluorodeoxycytidine (dFdC)) is a deoxycytidine analogue that is effective against solid tumors, including lung cancer and ovarian cancer. dFdC requires the phosphorylation by deoxycytidine kinase (dCK) as a primary step in its activation. Deficiency of dCK is associated with resistance against this compound both in vitro in cancer cell lines and in clinical practice in acute myeloid leukemia and solid tumors. The human ovarian cancer cell line AG6000 is 100,000-fold resistant against dFdC compared to its parent cell line A2780. This cell line proved to be dCK deficient in enzyme activity assays and by Western blot analysis, but by RT-PCR, a normal and a truncated dCK mRNA was found. Sequencing revealed that exon 3 was deleted from the dCK cDNA, resulting in a 74-aa-long open-reading frame due to the generation of a premature stop codon. No gross genomic alteration was observed at the dCK locus, suggesting the involvement of post-transcription mechanisms. Transient transfection experiments indicated that the truncated dCK transcripts are not translated to protein. To study the functional role of the truncated dCK transcripts, both A2780 cells and AG6000 cells were stably transfected with human and rat dCK. The results indicated that over-expression of full-length dCK genes in AG6000 failed to completely reverse the sensitivity to dFdC or other drugs.
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Affiliation(s)
- Ashraf Said Al-Madhoun
- Department of Molecular Biosciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
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40
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Smal C, Cardoen S, Bertrand L, Delacauw A, Ferrant A, Van den Berghe G, Van Den Neste E, Bontemps F. Activation of deoxycytidine kinase by protein kinase inhibitors and okadaic acid in leukemic cells. Biochem Pharmacol 2004; 68:95-103. [PMID: 15183121 DOI: 10.1016/j.bcp.2004.02.031] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2003] [Accepted: 02/25/2004] [Indexed: 11/29/2022]
Abstract
Deoxycytidine kinase (dCK) is a key enzyme in the deoxynucleoside salvage pathway and in the activation of numerous nucleoside analogues used in cancer and antiviral chemotherapy. Recent studies indicate that dCK activity might be regulated through reversible phosphorylation. Here, we report the effects of a large panel of protein kinase inhibitors on dCK activity in the B-leukemia cell line EHEB, both in basal conditions and in the presence of the nucleoside analogue 2-chloro-2'-deoxyadenosine (CdA) which induces activation of dCK. Except staurosporine and H-7 that significantly reduced the activation of dCK by CdA, no specific protein kinase inhibitor diminished basal dCK activity or its activation by CdA. In contrast, genistein, a general protein tyrosine kinase inhibitor, and AG-490, an inhibitor of JAK2 and JAK3, increased basal dCK activity more than two-fold. Two specific inhibitors of the MAPK/ERK pathway, PD-98059 and U-0126, also enhanced dCK activity. These data suggest that the JAK/MAPK pathway could be involved in the regulation of dCK. Moreover, we show that the activity of dCK, raised by CdA, can return to its initial level by treatment with protein phosphatase-2A (PP2A). Accordingly, dCK activity in intact cells increased upon incubation with okadaic acid (OA) at concentrations that should inhibit PP2A, but not protein phosphatase-1. Activation of dCK by protein kinase inhibitors and OA was also observed in CCRF-CEM cells and in chronic lymphocytic leukemia B-lymphocytes, suggesting a general mechanism of post-translational regulation of dCK, which could be exploited to enhance the activation of antileukemic nucleoside analogues.
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Affiliation(s)
- Caroline Smal
- Laboratory of Physiological Chemistry, Christian de Duve Institute of Cellular Pathology, Avenue Hippocrate 75, UCL-ICP 7539, B-1200 Brussels, Belgium
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41
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Löfgren C, Hjortsberg L, Blennow M, Lotfi K, Paul C, Eriksson S, Albertioni F. Mechanisms of cross-resistance between nucleoside analogues and vincristine or daunorubicin in leukemic cells. Biochem Biophys Res Commun 2004; 320:825-32. [PMID: 15240122 DOI: 10.1016/j.bbrc.2004.06.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2004] [Indexed: 11/25/2022]
Abstract
The aim of this study was to clarify the biochemical and molecular mechanisms behind the cross-resistance to nucleoside analogues (NAs) in four erythroleukemic cell lines with acquired resistance to the anthracycline daunorubicin and to the vinca alkaloid vincristine, expressing high levels of p-glycoprotein (P-gp, MDR1). All resistant strains exhibited cross-resistance to NA (cladribine and cytosine arabinoside)-induced apoptosis, assessed by caspase-3-like activation and were less sensitive to NA cytotoxicity in MTT assay. Real-time PCR and enzyme activity analysis showed reduced amounts of deoxycytidine kinase (35-80%) and elevated levels of 5'-nucleotidases (50-100%). The ratio 5'-nucleotidase to deoxycytidine kinase increased between 2.5- and 7.5-folds in resistant cells. This is in agreement with the observation that 5'-nucleotidase/deoxycytidine kinase ratio might be an important factor in predicting resistance to NAs. Implications of this finding for combining anthracyclines or vinca alkaloids with NAs toward leukemic cells are discussed.
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Affiliation(s)
- Christina Löfgren
- Department of Hematology, Huddinge University Hospital, Stockholm, Sweden.
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Abstract
The inherent or acquired resistance of leukemic cells to cytostatic agents is a major clinical challenge. The purpose of this review was to elucidate and analyse the available data concerning mechanisms of resistance of cladribine with emphasis on recent advances in the characterization of activating and inactivating enzymes in the induction of resistance to cladribine. All available in vitro and clinical data on cladribine was undertaken. Cladribine, unlike many other drugs, is toxic to both dividing and indolent lymphoid malignancies. Cladribine is a prodrug and must be phosphorylated intracellularly to cladribine-monophosphate (MP) by the nuclear/cystosol enzyme deoxycytidine kinase (dCK) and the mitochondrial enzyme deoxyguanosine kinase. The cytotoxicity mainly depends on the accumulation of cladribine-triphosphates (TP) after phosphorylation of cladribine-MP by nucleoside monophosphate kinase and nucleoside diphosphate kinase. 5'-Nucleotidase (5'-NT) dephosphorylates cladribine-MP and the accumulation of cladribine-TP depends on the ratio of dCK and 5'-NT in the cells. The mechanisms underlying cladribine resistance are multifactorial, e.g. decreased nucleoside transport, decreased activity or deficiency of dCK, altered intracellular pools of competing nucleotides, altered regulation of ribonucleotide reductase and increased drug inactivation by 5'-NT. Finally, cladribine resistance may be a consequence of a defective induction of apoptosis. In spite of the fact that more than one mechanism can contribute to a cladribine resistance phenotype, a reduction in dCK activity is probably the major determinant of cladribine resistance. Insight into the mechanism of action and resistance to cladribine is crucial for its optimal use as well as for the development of newer analogues.
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Affiliation(s)
- Kourosh Lotfi
- Department of Medicine and Care, Clinical Pharmacology, Faculty of Health Sciences, Linköping University, Linköping, SE-581 85 Sweden
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Bierau J, Leen R, Gennip AHV, Caron HN, Kuilenburg ABPV. Determination of the deoxycytidine kinase activity in cell homogenates with a non-radiochemical assay using reversed-phase high performance liquid chromatography. J Chromatogr B Analyt Technol Biomed Life Sci 2004; 805:339-46. [PMID: 15135110 DOI: 10.1016/j.jchromb.2004.03.036] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2003] [Revised: 03/02/2004] [Accepted: 03/17/2004] [Indexed: 11/30/2022]
Abstract
A non-radioactive procedure to measure the deoxycytidine kinase (dCK) activity in crude cell free homogenates was developed. 2-Chlorodeoxyadenosine (CdA) was used as the substrate for dCK and was separated from its product 2-chlorodeoxyadenosine-5'-monophosphate (CdAMP) by reversed-phase HPLC. A complete separation of CdA and its metabolites was achieved in 30 min. The minimum amount of CdAMP that could be detected was 1 pmol. The assay was linear with reaction times up to at least 3h. With respect to the protein concentration, the reaction was linear with protein concentrations up to 760 microg/ml in the assay. An amount of 8 x 10(3) cells was already sufficient to determine the specific dCK activity in SK-N-BE(2)c cells. CdA was not only converted to CdAMP but also to 2-chloroadenine and, surprisingly, also to 2-chlorodeoxyinosine, in MOLT-3 cells. The deamination of CdA was completely inhibited by deoxycoformycin, which clearly demonstrates that CdA is a substrate for adenosine deaminase.
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Affiliation(s)
- Jörgen Bierau
- Department of Clinical Chemistry, University of Amsterdam, Emma Children's Hospital, 1100 DE, The Netherlands
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Affiliation(s)
- R Pieters
- University Medical Center Rotterdam, Sophia Childrens Hospital, Pediatric Oncology/Hematology, Rotterdam, The Netherlands.
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45
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Galmarini CM, Clarke ML, Santos CL, Jordheim L, Perigaud C, Gosselin G, Cros E, Mackey JR, Dumontet C. Sensitization of ara-C-resistant lymphoma cells by a pronucleotide analogue. Int J Cancer 2003; 107:149-54. [PMID: 12925971 DOI: 10.1002/ijc.11339] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Adequate intracellular concentrations of ara-CMP, the monophosphorylated derivative of ara-C, are essential for its cytotoxicity. The critical step for ara-CMP formation is intracellular phosphorylation of ara-C by deoxycytidine kinase (dCK). A common nucleoside resistance mechanism is mutation affecting the expression or the specificity of dCK. We describe the ability of a tert-butyl S-acyl-thioethyl (SATE) derivative of ara-CMP (UA911) to circumvent ara-C resistance in a dCK-deficient human follicular lymphoma cell line (RL-G). The RL-G cell line was produced by continuous exposure to gemcitabine and displayed low dCK mRNA and protein expression that conferred resistance both to ara-C (2,250-fold) and to gemcitabine (2,092-fold). RL-G cells were able to take up the UA911 pronucleotide by diffusion and metabolize it to the corresponding ara-CMP and ara-CTP nucleotides, exhibiting a 199-fold reduction in resistance ratios, and a similar cell cycle arrest to the parental RL-7 cells. Exposures to 10, 50 or 100 microM concentrations of UA911 produced 160 +/- 7, 269 +/- 8 and 318 +/- 62 pmol ara-CTP/mg protein in RL-7 cells, and 100 +/- 12, 168 +/- 10 and 217 +/- 39 pmol ara-CTP/mg protein in RL-G cells, respectively. Exposure of RL-G cells to underivatized, radiolabeled ara-C produced no detectable amounts of the active triphosphate metabolites. We conclude that the UA911 pronucleotide is capable of overcoming dCK-mediated resistance. This result can be attributed to the unique cellular metabolism of the SATE pronucleotides giving rise to the intracellular delivery of ara-CMP to dCK-deficient cells.
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Affiliation(s)
- Carlos María Galmarini
- INSERM 590, Laboratoire de Cytologie Analytique, Faculté de Médecine Rockefeller, Lyon, France.
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46
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Galmarini CM, Thomas X, Graham K, El Jafaari A, Cros E, Jordheim L, Mackey JR, Dumontet C. Deoxycytidine kinase and cN-II nucleotidase expression in blast cells predict survival in acute myeloid leukaemia patients treated with cytarabine. Br J Haematol 2003; 122:53-60. [PMID: 12823345 DOI: 10.1046/j.1365-2141.2003.04386.x] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The cytotoxic activity of cytarabine (ara-C) in leukaemic blasts depends on activating enzymes such as deoxycytidine kinase (dCK) and inactivating enzymes such as the 5'-nucleotidases. We have analysed dCK and 'high-Km' 5'-nucleotidase (cN-II) mRNA expression by the quantitative real-time polymerase chain reaction at diagnosis in leukaemic blasts from 115 acute myeloid leukaemia (AML) patients treated with ara-C. The prognostic value of these parameters as well as that of the cN-II/dCK ratio was determined. In univariate analyses: (1) low levels of dCK, high levels of cN-II and a high cN-II/dCK ratio predicted shorter disease-free survival (DFS); (2) low levels of dCK and cN-II/dCK ratio also predicted shorter overall survival (OS). In a multivariate analysis taking into account other clinical and laboratory variables: (1) high cN-II expression, a high cN-II/dCK ratio, age >/= 60 years and an unfavourable karyotype were independent prognostic factors for DFS; and (2) a high cN-II/dCK ratio, age >/= 60 years and an unfavourable karyotype predicted shorter OS. Age, karyotype and cN-II/dCK ratio were used to define a prognostic score that permitted the identification of high- and low-risk groups. Our results suggest that dCK and cN-II mRNA expression in leukaemic blasts at diagnosis is correlated with clinical outcome and may play a functional role in the resistance to ara-C in patients with AML.
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Veuger MJT, Honders MW, Spoelder HE, Willemze R, Barge RMY. Inactivation of deoxycytidine kinase and overexpression of P-glycoprotein in AraC and daunorubicin double resistant leukemic cell lines. Leuk Res 2003; 27:445-53. [PMID: 12620296 DOI: 10.1016/s0145-2126(02)00224-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
AraC resistance in vitro is explained by inactivation of dCK, while resistance to DNR is described by overexpression of multidrug efflux pumps like Pgp or MRP. Thus far, no correlation between resistance mechanisms in vitro and in patients with AML has been documented. We generated AraC and DNR double resistant cell lines to investigate resistance mechanisms of both agents. In these cell lines involvement of dCK was extensively investigated and Pgp expression and activity was determined. Our data implicate that similar resistance mechanisms like inactivation of dCK coincided by alternatively spliced dCK forms and overexpression of Pgp are induced in single-as well as in double resistant leukemic cell lines.
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Affiliation(s)
- Marjan J T Veuger
- Laboratory of Experimental Hematology, C2-R, Leiden University Medical Center, Department of Hematology, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
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48
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Tawara M, Maeda T, Yamada Y, Harasawa H, Tsuruda K, Sugahara K, Moriuchi R, Tomonaga M, Kamihira S. Aberrant processing of Fas transcripts in adult T-cell leukemia: a possible role in tumor cell survival. Cancer Lett 2003; 193:235-42. [PMID: 12706882 DOI: 10.1016/s0304-3835(03)00006-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In adult T-cell leukemia (ATL), tumor cells commonly express abundant membrane-bound Fas antigen. We reported a significant correlation between Fas expression status of ATL patients and their clinical outcome. In the current study, we analyzed the Fas cDNA sequence of the distinctive ATL cases that barely expressed mFas identified during the previous study. According to the results, changes in the Fas amino acid sequence were deduced in two of seven cases. Furthermore, we identified seven novel variants of Fas mRNA produced by alternative splicing. Our data indicates the diversity of Fas gene expression at a mRNA level in ATL.
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Affiliation(s)
- Masayuki Tawara
- Department of Laboratory Medicine, Nagasaki University School of Medicine, Nagasaki, Japan
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Stoilov P, Meshorer E, Gencheva M, Glick D, Soreq H, Stamm S. Defects in pre-mRNA processing as causes of and predisposition to diseases. DNA Cell Biol 2002; 21:803-18. [PMID: 12489991 DOI: 10.1089/104454902320908450] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Humans possess a surprisingly low number of genes and intensively use pre-mRNA splicing to achieve the high molecular complexity needed to sustain normal body functions and facilitate responses to altered conditions. Because hundreds of thousands of proteins are generated by 25,000 to 40,000 genes, pre-mRNA processing events are highly important for the regulation of human gene expression. Both inherited and acquired defects in pre-mRNA processing are increasingly recognized as causes of human diseases, and almost all pre-mRNA processing events are controlled by a combination of protein factors. This makes defects in these processes likely candidates for causes of diseases with complicated inheritance patterns that affect seemingly unrelated functions. The elucidation of genetic mechanisms regulating pre-mRNA processing, combined with the development of drugs targeted at consensus RNA sequences and/or corresponding proteins, can lead to novel diagnostic and therapeutic approaches.
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Affiliation(s)
- Peter Stoilov
- University of Erlangen-Nurenberg, Institute of Biochemistry, 91054 Erlangen, Germany
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50
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Veuger MJT, Honders MW, Willemze R, Barge RMY. Deoxycytidine kinase expression and activity in patients with resistant versus sensitive acute myeloid leukemia. Eur J Haematol 2002; 69:171-8. [PMID: 12406011 DOI: 10.1034/j.1600-0609.2002.02785.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Resistance to cytarabine (AraC) is a major problem in treatment of patients with acute myeloid leukemia (AML). In contrast to in vitro AraC resistance, deoxycytidine kinase (dCK) mutations are rarely found in patients with refractory or relapsed AML. Previously we have demonstrated alternatively spliced dCK mRNA predominantly expressed in leukemic blasts from patients with resistant AML. In this study we investigated wild-type (wt) dCK expression and activity to elucidate the possible role of decreased dCK expression or activity in unresponsiveness to AraC in patients with AML. No alterations in dCK mRNA and protein expression or in dCK activity were detected between patients with clinically resistant vs. sensitive AML. In addition, wt dCK expression and activity were not reduced in leukemic blasts expressing alternatively spliced dCK forms as compared to blasts with only wt dCK. Also, no major differences in wt dCK expression and activity were observed between samples obtained from patients with AML and bone marrow or peripheral blood samples from healthy donors. These data implicate that in our patient group of refractory or relapsed AML cases, alterations in dCK expression and/or activity cannot explain unresponsiveness to chemotherapy including AraC.
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Affiliation(s)
- Marjan J T Veuger
- Laboratory of Experimental Hematology, Department of Hematology, Leiden University Medical Center, Leiden, The Netherlands
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