1
|
Sadıkoğulları BC, Şenel P, Çini N, Faysal AA, Odabaşoğlu M, Özdemir AD, Gölcü A. An Overview of Natural and Synthetic Phthalides Involved in Cancer Studies: Past, Present, and Future. ChemistrySelect 2022. [DOI: 10.1002/slct.202202004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Bleda Can Sadıkoğulları
- Istanbul Technical University Faculty of Sciences and Letters Department of Chemistry Istanbul 34469 Turkey
| | - Pelin Şenel
- Istanbul Technical University Faculty of Sciences and Letters Department of Chemistry Istanbul 34469 Turkey
| | - Nejla Çini
- Istanbul Technical University Faculty of Sciences and Letters Department of Chemistry Istanbul 34469 Turkey
| | - Abdullah Al Faysal
- Istanbul Technical University Faculty of Sciences and Letters Department of Chemistry Istanbul 34469 Turkey
| | - Mustafa Odabaşoğlu
- Karadeniz Technical University Faculty of Sciences and Letters Department of Chemistry Trabzon 61080 Turkey
| | - Ayşe Daut Özdemir
- Istanbul Technical University Faculty of Sciences and Letters Department of Chemistry Istanbul 34469 Turkey
| | - Ayşegül Gölcü
- Istanbul Technical University Faculty of Sciences and Letters Department of Chemistry Istanbul 34469 Turkey
| |
Collapse
|
2
|
Liu B, Liu Z, Wang Y, Lian X, Han Z, Cheng X, Zhu Y, Liu R, Zhao Y, Gao Y. Overexpression of GINS4 is associated with poor prognosis and survival in glioma patients. Mol Med 2021; 27:117. [PMID: 34556022 PMCID: PMC8461916 DOI: 10.1186/s10020-021-00378-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 09/11/2021] [Indexed: 12/21/2022] Open
Abstract
Background GINS4, an indispensable component of the GINS complex, is vital for a variety of cancer. However, no known empirical research has focused on exploring relationships between GINS4 and glioma. Thus, this study aims to understand and explain the role of GINS4 in glioma. Method First, we used the data in the CGGA, TCGA, GEO, GEPIA, and HPA databases to explore the expression level of GINS4 in glioma, the correlation between GINS4 expression and the clinical features of glioma, its impact on the survival of glioma patients, and verified the analysis results through RT-qPCR, IHC, and meta-analysis. Subsequently, GSEA enrichment analysis is used to find the potential molecular mechanism of GINS4 to promote the malignant process of glioma and the anti-glioma drugs that may target GINS4 screened by CMap analysis. Moreover, we further explored the influence of the GINS4 expression on the immune microenvironment of glioma patients through the TIMER database. Results Our results suggested that GINS4 was elevated in glioma, and the overexpression of GINS4 was connected with a vast number of clinical features. The next, GINS4 as an independent prognostic factor, which can result in an unfavorable prognosis of glioma. Once more, GINS4 may be participating in the oncogenesis of glioma through JAK-STAT signaling pathways, etc. 6-thioguanine, Doxazosin, and Emetine had potential value in the clinical application of drugs targeting GINS4. Finally, the expression exhibited a close relationship with some immune cells, especially Dendritic cells. Conclusion GINS4 is an independent prognostic factor that led to a poor prognosis of glioma. The present study revealed the probable underlying molecular mechanisms of GINS4 in glioma and provided a potential target for improving the prognosis of glioma. Supplementary Information The online version contains supplementary material available at 10.1186/s10020-021-00378-0.
Collapse
Affiliation(s)
- Binfeng Liu
- Zhengzhou University People's Hospital, Henan Provincial People's Hospital, Henan, 450003, Zhengzhou, China
| | - Zhendong Liu
- Department of Surgery of Spine and Spinal Cord, Henan Provincial People's Hospital, Henan International Joint Laboratory of Intelligentized Orthopedics Innovation and Transformation, Henan Key Laboratory for Intelligent Precision Orthopedics, People's Hospital of Zhengzhou University, People's Hospital of Henan University, Henan, 450003, Zhengzhou, China
| | - Yanbiao Wang
- Department of Orthopedics, First Affiliated Hospital of Xinxiang Medical College, Xinjiang, China
| | - Xiaoyu Lian
- Zhengzhou University People's Hospital, Henan Provincial People's Hospital, Henan, 450003, Zhengzhou, China
| | - Zhibin Han
- Department of Neurosurgery of the First Affiliate Hospital of Harbin Medical University, Harbin, China
| | - Xingbo Cheng
- Department of Neurosurgery of the First Affiliate Hospital of Harbin Medical University, Harbin, China
| | - Yongjie Zhu
- Department of Surgery of Spine and Spinal Cord, Henan University People's Hospital, Henan Provincial People's Hospital, Henan, 450003, Zhengzhou, China
| | - Runze Liu
- Department of Surgery of Spine and Spinal Cord, Henan University People's Hospital, Henan Provincial People's Hospital, Henan, 450003, Zhengzhou, China
| | - Yaoye Zhao
- Zhengzhou University People's Hospital, Henan Provincial People's Hospital, Henan, 450003, Zhengzhou, China
| | - Yanzheng Gao
- Department of Surgery of Spine and Spinal Cord, Henan Provincial People's Hospital, Henan International Joint Laboratory of Intelligentized Orthopedics Innovation and Transformation, Henan Key Laboratory for Intelligent Precision Orthopedics, People's Hospital of Zhengzhou University, People's Hospital of Henan University, Henan, 450003, Zhengzhou, China.
| |
Collapse
|
3
|
Huq S, Casaos J, Serra R, Peters M, Xia Y, Ding AS, Ehresman J, Kedda JN, Morales M, Gorelick NL, Zhao T, Ishida W, Perdomo-Pantoja A, Cecia A, Ji C, Suk I, Sidransky D, Brait M, Brem H, Skuli N, Tyler B. Repurposing the FDA-Approved Antiviral Drug Ribavirin as Targeted Therapy for Nasopharyngeal Carcinoma. Mol Cancer Ther 2020; 19:1797-1808. [PMID: 32606016 DOI: 10.1158/1535-7163.mct-19-0572] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 12/09/2019] [Accepted: 06/09/2020] [Indexed: 11/16/2022]
Abstract
Nasopharyngeal carcinoma (NPC) is a squamous cell carcinoma with a proclivity for systemic dissemination, leading many patients to present with advanced stage disease and fail available treatments. There is a notable lack of targeted therapies for NPC, despite working knowledge of multiple proteins with integral roles in NPC cancer biology. These proteins include EZH2, Snail, eIF4E, and IMPDH, which are all overexpressed in NPC and correlated with poor prognosis. These proteins are known to be modulated by ribavirin, an FDA-approved hepatitis C antiviral that has recently been repurposed as a promising therapeutic in several solid and hematologic malignancies. Here, we investigated the potential of ribavirin as a targeted anticancer agent in five human NPC cell lines. Using cellular growth assays, flow cytometry, BrdU cell proliferation assays, scratch wound assays, and invasion assays, we show in vitro that ribavirin decreases NPC cellular proliferation, migration, and invasion and promotes cell-cycle arrest and cell death. Modulation of EZH2, Snail, eIF4E, IMPDH, mTOR, and cyclin D1 were observed in Western blots and enzymatic activity assays in response to ribavirin treatment. As monotherapy, ribavirin reduced flank tumor growth in multiple NPC xenograft models in vivo Most importantly, we demonstrate that ribavirin enhanced the effects of radiotherapy, a central component of NPC treatment, both in vitro and in vivo Our work suggests that NPC responds to ribavirin-mediated EZH2, Snail, eIF4E, IMPDH, and mTOR changes and positions ribavirin for clinical evaluation as a potential addition to our NPC treatment armamentarium.
Collapse
Affiliation(s)
- Sakibul Huq
- Hunterian Neurosurgical Research Laboratory, Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Joshua Casaos
- Hunterian Neurosurgical Research Laboratory, Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Riccardo Serra
- Hunterian Neurosurgical Research Laboratory, Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Michael Peters
- Hunterian Neurosurgical Research Laboratory, Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Yuanxuan Xia
- Hunterian Neurosurgical Research Laboratory, Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Andy S Ding
- Hunterian Neurosurgical Research Laboratory, Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Jeff Ehresman
- Hunterian Neurosurgical Research Laboratory, Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Jayanidhi N Kedda
- Hunterian Neurosurgical Research Laboratory, Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Manuel Morales
- Hunterian Neurosurgical Research Laboratory, Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Noah L Gorelick
- Hunterian Neurosurgical Research Laboratory, Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Tianna Zhao
- Hunterian Neurosurgical Research Laboratory, Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Wataru Ishida
- Hunterian Neurosurgical Research Laboratory, Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Alexander Perdomo-Pantoja
- Hunterian Neurosurgical Research Laboratory, Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Arba Cecia
- Hunterian Neurosurgical Research Laboratory, Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Chenchen Ji
- Hunterian Neurosurgical Research Laboratory, Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Ian Suk
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - David Sidransky
- Head and Neck Cancer Research Laboratory, Department of Otolaryngology and Head & Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Mariana Brait
- Head and Neck Cancer Research Laboratory, Department of Otolaryngology and Head & Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Henry Brem
- Hunterian Neurosurgical Research Laboratory, Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland.,Departments of Biomedical Engineering, Oncology, and Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Nicolas Skuli
- Hunterian Neurosurgical Research Laboratory, Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Betty Tyler
- Hunterian Neurosurgical Research Laboratory, Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland.
| |
Collapse
|
4
|
Liu J, Feng M, Li S, Nie S, Wang H, Wu S, Qiu J, Zhang J, Cheng W. Identification of molecular markers associated with the progression and prognosis of endometrial cancer: a bioinformatic study. Cancer Cell Int 2020; 20:59. [PMID: 32099532 PMCID: PMC7031962 DOI: 10.1186/s12935-020-1140-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Accepted: 02/10/2020] [Indexed: 12/19/2022] Open
Abstract
Background Endometrial cancer (EC) is one kind of women cancers. Bioinformatic technology could screen out relative genes which made targeted therapy becoming conventionalized. Methods GSE17025 were downloaded from GEO. The genomic data and clinical data were obtained from TCGA. R software and bioconductor packages were used to identify the DEGs. Clusterprofiler was used for functional analysis. STRING was used to assess PPI information and plug-in MCODE to screen hub modules in Cytoscape. The selected genes were coped with functional analysis. CMap could find EC-related drugs that might have potential effect. Univariate and multivariate Cox proportional hazards regression analyses were performed to predict the risk of each patient. Kaplan–Meier curve analysis could compare the survival time. ROC curve analysis was performed to predict value of the genes. Mutation and survival analysis in TCGA database and UALCAN validation were completed. Immunohistochemistry staining from Human Protein Atlas database. GSEA, ROC curve analysis, Oncomine and qRT-PCR were also performed. Results Functional analysis showed that the upregulated DEGs were strikingly enriched in chemokine activity, and the down-regulated DEGs in glycosaminoglycan binding. PPI network suggested that NCAPG was the most relevant protein. CMap identified 10 small molecules as possible drugs to treat EC. Cox analysis showed that BCHE, MAL and ASPM were correlated with EC prognosis. TCGA dataset analysis showed significantly mutated BHCE positively related to EC prognosis. MAL and ASPM were further validated in UALCAN. All the results demonstrated that the two genes might promote EC progression. The profile of ASPM was confirmed by the results from immunohistochemistry. ROC curve demonstrated that the mRNA levels of two genes exhibited difference between normal and tumor tissues, indicating their diagnostic efficiency. qRT-PCR results supported the above results. Oncomine results showed that DNA copy number variation of MAL was significantly higher in different EC subtypes than in healthy tissues. GSEA suggested that the two genes played crucial roles in cell cycle. Conclusion BCHE, MAL and ASPM are tumor-related genes and can be used as potential biomarkers in EC treatment.
Collapse
Affiliation(s)
- JinHui Liu
- Department of Gynecology, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029 Jiangsu China
| | - Mingming Feng
- Department of Gynecology, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029 Jiangsu China
| | - SiYue Li
- Department of Gynecology, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029 Jiangsu China
| | - Sipei Nie
- Department of Gynecology, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029 Jiangsu China
| | - Hui Wang
- Department of Gynecology, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029 Jiangsu China
| | - Shan Wu
- Department of Gynecology, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029 Jiangsu China
| | - Jiangnan Qiu
- Department of Gynecology, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029 Jiangsu China
| | - Jie Zhang
- Department of Gynecology, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029 Jiangsu China
| | - WenJun Cheng
- Department of Gynecology, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029 Jiangsu China
| |
Collapse
|
5
|
Klaasen RA, Bergan S, Bremer S, Hole K, Nordahl CB, Andersen AM, Midtvedt K, Skauby MH, Vethe NT. Pharmacodynamic assessment of mycophenolic acid in resting and activated target cell population during the first year after renal transplantation. Br J Clin Pharmacol 2020; 86:1100-1112. [PMID: 31925806 PMCID: PMC7256122 DOI: 10.1111/bcp.14218] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 12/10/2019] [Accepted: 12/19/2019] [Indexed: 12/31/2022] Open
Abstract
Aims To explore the pharmacodynamics of mycophenolic acid (MPA) through inosine monophosphate dehydrogenase (IMPDH) capacity measurement and purine levels in peripheral blood mononuclear cells (PBMC) longitudinally during the first year after renal transplantation (TX). Methods PBMC were isolated from renal recipients 0–4 days prior to and 6–9 days, 5–7 weeks and 1 year after TX (before and 1.5 hours after dose). IMPDH capacity and purine (guanine and adenine) levels were measured in stimulated and nonstimulated PBMC. Results Twenty‐nine patients completed the follow‐up period, of whom 24 received MPA. In stimulated PBMC, the IMPDH capacity (pmol 10−6 cells min−1) was median (interquartile range) 127 (95.8–147) before TX and thereafter 44.9 (19.2–93.2) predose and 12.1 (4.64–23.6) 1.5 hours postdose across study days after TX. The corresponding IMPDH capacity in nonstimulated PBMC was 5.71 (3.79–6.93), 3.35 (2.31–5.62) and 2.71 (1.38–4.08), respectively. Predose IMPDH capacity in nonstimulated PBMC increased with time, reaching pre‐TX values at 1 year. In stimulated PBMC, both purines were reduced before (median 39% reduction across days after TX) and after (69% reduction) dose compared to before TX. No alteration in the purine levels was observed in nonstimulated PBMC. Patients needing dose reductions during the first year had lower pre‐dose IMPDH capacity in nonstimulated PBMC (1.87 vs 3.00 pmol 10−6 cells min−1, P = .049) at 6–9 days. Conclusion The inhibitory effect of MPA was stronger in stimulated PBMC. Nonstimulated PBMC became less sensitive to MPA during the first year after TX. Early IMPDH capacity appeared to be predictive of dose reductions.
Collapse
Affiliation(s)
| | - Stein Bergan
- Department of Pharmacology, Oslo University Hospital, Oslo, Norway
| | - Sara Bremer
- Department of Medical Biochemistry, Oslo University Hospital, Oslo, Norway
| | - Kristine Hole
- Department of Pharmacology, Oslo University Hospital, Oslo, Norway
| | | | | | - Karsten Midtvedt
- Department of Transplantation Medicine, Oslo University Hospital, Oslo, Norway
| | - Morten Heier Skauby
- Department of Transplantation Medicine, Oslo University Hospital, Oslo, Norway
| | - Nils Tore Vethe
- Department of Pharmacology, Oslo University Hospital, Oslo, Norway
| |
Collapse
|
6
|
Zou J, Han Z, Zhou L, Cai C, Luo H, Huang Y, Liang Y, He H, Jiang F, Wang C, Zhong W. Elevated expression of IMPDH2 is associated with progression of kidney and bladder cancer. Med Oncol 2014; 32:373. [PMID: 25465060 DOI: 10.1007/s12032-014-0373-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Accepted: 11/14/2014] [Indexed: 11/30/2022]
Abstract
Novel molecular markers for cancer progression are valuable for the diagnosis and evaluation of treatment efficacies of the diseases. Expression of inosine 5'-monophosphate dehydrogenase type II (IMPDH2), a rate-limiting enzyme in the de novo guanine nucleotide biosynthesis, is up-regulated in various neoplasms, including prostate cancer and patient serum. However, whether IMPDH2 can serve as a biomarker for other urologic cancers is unknown. Paired patient tissue macroarrays were analyzed by immunohistochemistry, the IMPDH2 protein expression in these tissues was quantitated and expressed as immunoreactivity scores. Compared with non-cancerous tissues, IMPDH2 protein expression levels were significantly upregulated in kidney and bladder cancer, but no difference in testis cancer. In addition, expression of IMPDH2 was not associated with the disease clinical stages and pathological features. The findings suggest that overexpressed IMPDH2 can be used as a biomarker for kidney and bladder cancer diagnosis and is a potential therapeutic target for the diseases.
Collapse
Affiliation(s)
- Jun Zou
- Guangdong Provincial Institute of Nephrology, Southern Medical University, Guangzhou, 510515, China
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
7
|
The role of inosine-5'-monophosphate dehydrogenase in thiopurine metabolism in patients with inflammatory bowel disease. Ther Drug Monit 2011; 33:200-8. [PMID: 21311411 DOI: 10.1097/ftd.0b013e31820b42bb] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND There is a large interindividual variability in thiopurine metabolism. High concentrations of methylthioinosine-5'-monophosphate (meTIMP) and low concentrations of 6-thioguanine nucleotides (6-TGNs) have been associated with a lower response rate and an increased risk of adverse events. In this study, the role of inosine-5'-monophosphate dehydrogenase (IMPDH) for differences in metabolite patterns of thiopurines was investigated. METHODS IMPDH activity and thiopurine metabolite concentrations were determined in patients with inflammatory bowel disease and a normal thiopurine methyltransferase (TPMT) phenotype and meTIMP/6-TGN concentration ratio > 20 (n = 26), in patients with a metabolite ratio ≤ 20 (n = 21), in a subgroup with a metabolite ratio <4 (n = 6), and in 10 patients with reduced TPMT activity. In vitro studies were conducted on human embryonic kidney cells (HEK293) with genetically engineered IMPDH and TPMT activities. RESULTS Patients with metabolite ratios >20 had lower IMPDH activity than those with ratios ≤ 20 (P < 0.001). Metabolite ratios >20 were only observed in patients with normal TPMT activity. Downregulation of IMPDH activity in HEK293 cells was associated with an increase in the concentration of meTIMP (fold change: 17 up to 93, P < 0.001) but, unexpectedly, also of 6-thioguanosine monophosphate (fold change: 2.6 up to 5.0, P < 0.001). CONCLUSIONS These data question the general view of IMPDH as the rate-limiting enzyme in the phosphorylation of thiopurines. Investigations of other mechanisms are needed to more fully explain the various metabolite patterns and outcomes in patients under treatment.
Collapse
|
8
|
Pharmacodynamics of mycophenolic acid in CD4+ cells: a single-dose study of IMPDH and purine nucleotide responses in healthy individuals. Ther Drug Monit 2009; 30:647-55. [PMID: 18806697 DOI: 10.1097/ftd.0b013e31818955c3] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Mycophenolate mofetil is used in rejection prophylaxis after allograft transplantation. The highly variable pharmacokinetics and pharmacodynamics (PD) of the active moiety mycophenolic acid (MPA) render this drug attractive for therapeutic monitoring. The aim of this study was to characterize the exposure-response relationship for MPA to guide future strategies for individualized therapy based on PD monitoring. A single-dose (100, 250, 500, and 1000 mg mycophenolate mofetil) crossover exposure-response study of MPA PD in CD4 cells was performed in 5 healthy individuals. The activity of inosine 5'-monophosphate dehydrogenase (IMPDH) at time 0 ranged from 1.2 to 7.2 pmol per 10 cells/min. IMPDH was strongly inhibited by MPA; MPA EC50 (concentration required for 50% inhibition) of 2.3 mg/L was determined by a pooled data analysis. Decreased IMPDH gene expression was associated with the exposure to MPA. There were no immediate reductions of guanine nucleotides. On the contrary, a trend toward increased guanosine triphosphate was observed. IMPDH activity AUC0-12h approached maximum reduction at MPA AUC0-12h 22 mg x h/L (corresponding to the 500 mg dose), whereas plasma concentrations exceeding approximately 6 mg/L did not further increase the IMPDH inhibition. The results suggest that guanine nucleotides in circulating lymphocytes may not serve as immediate response biomarkers to MPA. Strategies for preventing over- or underexposure to MPA may be developed by means of IMPDH activity combined with MPA concentration measurement.
Collapse
|