| 1. |
- Björn, Niclas, et al.
(författare)
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ABCB1 Variation Affects Myelosuppression, Progression-free Survival and Overall Survival in Paclitaxel/Carboplatin-treated Ovarian Cancer Patients
- 2018
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Ingår i: Basic & Clinical Pharmacology & Toxicology. - : WILEY. - 1742-7835 .- 1742-7843. ; 123:3, s. 277-287
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Tidskriftsartikel (refereegranskat)abstract
- The standard chemotherapy for ovarian cancer is paclitaxel/carboplatin. Patients often exhibit myelosuppressive toxicity, and the treatment response varies considerably. In this study, we investigated the previously reported SNPs 1199Gamp;gt;A (rs2229109), 1236Camp;gt;T (rs1128503), 2677Gamp;gt;T/A (rs2032582), 3435Camp;gt;T (rs1045642) in ABCB1, and 1196Aamp;gt;G (rs10509681) in CYP2C8 and their association with treatment-induced myelosuppression, progression-free survival (PFS) and overall survival (OS). From the phase III study, OAS-07OVA, 525 patients (All) treated with carboplatin and paclitaxel administered as Paclical (Arm A, n=260) or Taxol((R)) (Arm B, n=265) were included and genotyped using pyrosequencing. Genotype associations with myelosuppression, PFS and OS were investigated using anova, Kaplan-Meier analysis and Cox proportional hazard models. The most prominent finding was for the ABCB1 variant 3435TT, which was significantly associated with increased PFS in All (hazard ratio (HR) = 0.623), in Arm A (HR=0.590) and in Arm B (HR=0.627), as well as increased OS in All (HR=0.443) and in Arm A (HR=0.372) compared to the wild-type, 3435CC. For toxicity, the most interesting finding concerned the haplotype, including 1236TT, 2677TT and 3435TT, which was associated with higher neutrophil values in Arm B (p=0.039) and less neutrophil decrease in All (p=0.048) and in Arm B (p=0.021). It is noteworthy that the results varied depending on the treatment arm which indicates that the effects of ABCB1 variants vary with the treatment regimen. Our results reflect the contradictory results of previous studies, confirming that small variations in the composition of treatment regimens and patient populations may influence the interpretation of SNPs effects on treatment outcome.
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| 2. |
- Björn, Niclas, et al.
(författare)
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The association of four genetic variants with myelosuppression in gemcitabine-treated Japanese is not evident in gemcitabine/carboplatin-treated Swedes
- 2022
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Ingår i: Basic & Clinical Pharmacology & Toxicology. - : John Wiley & Sons. - 1742-7835 .- 1742-7843. ; 130:4, s. 513-521
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Tidskriftsartikel (refereegranskat)abstract
- Gemcitabine/carboplatin-induced myelosuppressive adverse drug reactions (ADRs) are clinical problems leading to patient suffering and dose alterations. There is a need for personalised medicine to improve treatment effects and patients' well-being. We tested four genetic variants, rs11141915, rs1901440, rs12046844 and rs11719165, previously suggested as potential biomarkers for gemcitabine-induced leukopenia/neutropenia in Japanese patients, in 213 Swedish gemcitabine/carboplatin-treated non-small cell lung cancer (NSCLC) patients. DNA was genotyped using TaqMan probes and real-time PCR. The relationships between the risk alleles and low toxicity (non-ADR: Common Terminology Criteria for Adverse Events [CTCAE] grades 0) or high toxicity (ADR: CTCAE grades 3-4) of platelets, leukocytes and neutrophils were evaluated using Fisher's exact test. The risk alleles did not correlate with myelosuppression, and the strongest borderline significance (not withstanding adjustment for multiple testing) was for rs1901440 (neutropenia, p = 0.043) and rs11719165 (leukopenia, p = 0.049) where the risk alleles trended towards lower toxicity, contrasting with previous study findings. Risk alleles and higher risk scores were more common among our patients. We conclude that the genetic variants do not apply to Swedish patients treated with gemcitabine/carboplatin. However, they can still be important in other populations and cohorts, especially in a gemcitabine monotherapy setting, where the causal genetic variation might influence myelosuppressive ADRs.
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| 3. |
- Boiso, Samuel, et al.
(författare)
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ABCB1 gene polymorphisms are associated with suicide in forensic autopsies
- 2013
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Ingår i: Pharmacogenetics & Genomics. - : Lippincott, Williams and Wilkins. - 1744-6872 .- 1744-6880. ; 23:9, s. 463-469
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Tidskriftsartikel (refereegranskat)abstract
- Background Polymorphisms in ABCB1 have the ability to affect both the function and the expression of the transporter protein P-glycoprotein and may lead to an altered response for many drugs including some antidepressants and antipsychotics.Objective The aim of this study was to examine the impact of the ABCB1 polymorphisms 1199Gandgt;A, 1236Candgt;T, 2677Gandgt;T/A, and 3435Candgt;T in deaths by suicide.Patients and methods A total of 998 consecutive Swedish forensic autopsies performed in 2008 in individuals 18 years of age or older, where femoral blood was available and a toxicological screening had been performed, were investigated. Genotypes were assessed with pyrosequencing and information on the cause and manner of each death was obtained from the forensic pathology and toxicology databases.Results There was a significantly higher frequency of the T allele at positions 1236, 2677, and 3435 among the suicide cases compared with the nonsuicide cases.Conclusion Our result from forensic cases suggests that ABCB1 polymorphisms are associated with an increased risk for completed suicides. The biological mechanisms involved and the clinical implications for these findings are largely unknown and need to be examined further.
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| 4. |
- Coulthard, Sally A, et al.
(författare)
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Increased Sensitivity to Thiopurines in Methylthioadenosine Phosphorylase-Deleted Cancers
- 2011
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Ingår i: MOLECULAR CANCER THERAPEUTICS. - : AMER ASSOC CANCER RESEARCH, 615 CHESTNUT ST, 17TH FLOOR, PHILADELPHIA, PA 19106-4404 USA. - 1535-7163. ; 10:3, s. 495-504
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Tidskriftsartikel (refereegranskat)abstract
- The thiopurines, 6-mercaptopurine (6-MP) and 6-thioguanine (6-TG), are used in the treatment of leukemia. Incorporation of deoxythioguanosine nucleotides (dG(s)) into the DNA of thiopurine-treated cells causes cell death, but there is also evidence that thiopurine metabolites, particularly the 6-MP metabolite methylthioinosine monophosphate (MeTIMP), inhibit de novo purine synthesis (DNPS). The toxicity of DNPS inhibitors is influenced by methylthioadenosine phosphorylase (MTAP), a gene frequently deleted in cancers. Because the growth of MTAP-deleted tumor cells is dependent on DNPS or hypoxanthine salvage, we would predict such cells to show differential sensitivity to 6-MP and 6-TG. To test this hypothesis, sensitivity to 6-MP and 6-TG was compared in relation to MTAP status using cytotoxicity assays in two MTAP-deficient cell lines transfected to express MTAP: the T-cell acute lymphoblastic leukemic cell line, Jurkat, transfected with MTAP cDNA under the control of a tetracycline-inducible promoter, and a lung cancer cell line (A549-MTAP(-)) transfected to express MTAP constitutively (A549-MTAP(+)). Sensitivity to 6-MP or methyl mercaptopurine riboside, which is converted intracellularly to MeTIMP, was markedly higher in both cell lines under MTAP(-) conditions. Measurement of thiopurine metabolites support the hypothesis that DNPS inhibition is a major cause of cell death with 6-MP, whereas dG(s) incorporation is the main cause of cytotoxicity with 6-TG. These data suggest that thiopurines, particularly 6-MP, may be more effective in patients with deleted MTAP.
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| 5. |
- Coulthard, Sally, et al.
(författare)
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Increased sensitivity to thiopurines in methylthioadenosine phosphorylase-deleted cancers in PURINERGIC SIGNALLING, vol 6, issue , pp 33-33
- 2010
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Ingår i: PURINERGIC SIGNALLING. - : Springer Science Business Media. ; , s. 33-33
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Konferensbidrag (refereegranskat)abstract
- The thiopurines, 6-mercaptopurine (6-MP) and 6-thioguanine (6-TG) are used in the treatment of leukaemia. Incorporation of deoxythioguanosine nucleotides (dGs) into the DNA of thiopurine-treated cells causes cell death but there is also evidence that thiopurine metabolites, particularly the 6-MP metabolite methylthioinosine monophosphate (MeTIMP), inhibit de novo purine synthesis (DNPS). The toxicity of DNPS inhibitors is influenced by methylthioadenosine phosphorylase (MTAP), a gene frequently deleted in cancers. Since the growth of MTAP-deleted tumour cells is dependent on DNPS or hypoxanthine salvage, we would predict such cells to show differential sensitivity to 6-MP and 6-TG. To test this hypothesis, sensitivity to 6-MP and 6-TG was compared in relation to MTAP status using cytotoxicity assays in two MTAP-deficient cell lines transfected to express MTAP: the T-cell acute lymphoblastic leukaemic cell line, Jurkat, transfected with MTAP cDNA under the control of a tetracycline-inducible promoter, and a lung cancer cell line (A549-MTAP-ve) transfected to express MTAP constitutively (A549-MTAP+ve). Sensitivity to 6-MP or methyl mercaptopurine riboside, which is converted intra-cellularly to MeTIMP, was markedly higher in both cell lines under MTAP-ve conditions. Measurement of thiopurine metabolites support the hypothesis that DNPS inhibition is a major cause of cell death with 6-MP, whereas dGs incorporation is the main cause of cytotoxicity with 6-TG. These data suggest that thiopurines, particularly 6-MP, may be more effective in patients with deleted MTAP.
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| 6. |
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| 7. |
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| 8. |
- Green, Henrik, et al.
(författare)
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Association of ABCB1 polymorphisms with survival and in vitro cytotoxicty in de novo acute myeloid leukemia with normal karyotype
- 2012
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Ingår i: The Pharmacogenomics Journal. - : Nature Publishing Group. - 1470-269X .- 1473-1150. ; 12:2, s. 111-118
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Tidskriftsartikel (refereegranskat)abstract
- Overexpression of the multi-drug transporter P-glycoprotein, encoded by the ABCB1 gene, is a clinically relevant problem in acute myeloid leukemia (AML). Polymorphisms in ABCB1 might contribute to cancer risk and therapeutic response. We therefore investigated the influence of polymorphisms G1199A, C1236T, G2677T/A and C3435T on cancer susceptibility, in vitro cytotoxicity and overall survival in 100 de novo AML patients with normal karyotype. Patients with 1236C/C or 2677G/G genotypes showed poorer survival than patients with other genotypes (P = 0.03 and P = 0.02, respectively). Both these genotypes were significant factors for survival in multivariate analysis, along with age, NPM1 and FLT3 mutation status. In vitro cytotoxicity studies demonstrated that leukemic cells from 1236T/T and 2677T/T patients were significantly more susceptible to mitoxantrone (P 0.02), and tended to be more susceptible to etoposide and daunorubicin (P = 0.07-0.09), but not to cytarabine. No significant difference in allele frequencies was found between patients and healthy volunteers (n = 400).
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| 9. |
- Green, Henrik, et al.
(författare)
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Impact of CYP3A5(*)3 and CYP2C8-HapC on Paclitaxel/Carboplatin-Induced Myelosuppression in Patients with Ovarian Cancer
- 2011
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Ingår i: Journal of Pharmaceutical Sciences. - : Elsevier. - 0022-3549 .- 1520-6017. ; 100:10, s. 4205-4209
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Tidskriftsartikel (refereegranskat)abstract
- The influence of genetic variants on paclitaxel-induced toxicity is of considerable interest for reducing adverse drug reactions. Recently, the genetic variants CYP2C8(*)3, CYP2C8-HapC, and CYP3A5(*)3 were associated with paclitaxel-induced neurotoxicity. We, therefore, investigated the impact of CYP2C8-HapC and CYP3A5(*)3 on paclitaxel/carboplatin-induced myelosuppression and neurotoxicity. Thirty-three patients from a prospective pharmacokinetics study were genotyped using pyrosequencing. Patients with variant alleles of CYP2C8-HapC were found to have significantly lower nadir values of both leukocytes and neutrophils (p andlt; 0.05) than patients with the wild-type genotype. CYP3A5(*)3/(*)1 patients were shown to have borderline, significantly lower nadir values of leukocytes (p = 0.07) than (*)3/(*)3 patients. Combining the two genotypes resulted in a significant correlation with both leukopenia and neutropenia (p = 0.01). No effect of these genetic variants on neurotoxicity could be shown in this rather small study, but their importance for paclitaxel-induced toxicity could be confirmed.
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| 10. |
- Jakobsen Falk, Ingrid, et al.
(författare)
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Association of CYP2B6 Genotype with Survival and Progression Free Survival in Cyclophosphamide Treated Multiple Myeloma
- 2012
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Ingår i: Journal of Cancer Therapy. - : Scientific Research Publishing. - 2151-1934 .- 2151-1942. ; 3:1, s. 20-27
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Cyclophosphamide is a conventional pro-drug used in Multiple Myeloma (MM) and other malignancies. The highly polymorphic CYP2B6 is suggested as a major contributor in cyclophosphamide bioactivation, and GST en-zymes are involved in detoxification. Polymorphisms of these enzymes may affect enzyme expression and function as well as treatment outcome. The aim of this study was to investigate the impact of the CYP2B6 SNPs G516T, A785G and C1459T, GSTP1 SNP Ile105Val, and GSTM1 and GSTT1 null variants, on the outcome for cyclophosphamide treated MM patients, in order to find markers of value for individualised therapy. Methods: We used allele specific PCR and Pyrosequencing to investigate the impact of CYP2B6 SNPs G516T, A785G and C1459T, GSTP1 Ile105Val, and GSTM1 and GSTT1 variants, on the outcome for 26 cyclophosphamide treated multiple myeloma patients. Results and Major Conclusion: The CYP2B6 785G carriers had significantly shorter progression free survival (p = 0.048*) and overall survival (p = 0.037*) with 785G/G patients having the worst outcome compared to patients carrying the wild type. A shorter progression free survival was also indicated in patients carrying both CYP2B6 516T & 785G (p = 0.068). These results indicate a predictive role of CYP2B6 SNPs, particularly A785G, in cyclophosphamide treatment.
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