Association of C35T polymorphism in dihydrofolate reductase gene with toxicity of methotrexate in rheumatoid arthritis patients

Background: Methotrexate (MTX), a folate analogue, is the most commonly used disease-modifying drug in the treatment of rheumatoid arthritis (RA). However, high interindividual differences in drug response are present among RA patients.Research design and methods: In a group of 234 RA patients treated with MTX, we investigated whether rs1650697 polymorphism in DHFR gene may have an impact on MTX efficacy and/or adverse drug effects (ADEs). Relative DAS28 values (rDAS28) were used for the estimation of MTX therapy and all ADEs were recorded. Patients were genotyped for selected polymorphism by real-time PCR method. Results: According to the European League Against Rheumatism criteria after 6 months of MTX therapy, 196 patients (83.8%) were classified as responders (25 (10.7%) were good and 171 (73.1%) were moderate) and 38 patients (16.2%) as nonresponders. ADEs were observed in 55 patients (23.5%). Conclusions: Our results showed that the presence of T allele might be protective against MTX hepatotoxicity measured by transaminase levels (p = 0.05). Furthermore, among patients who also received low-dose corticosteroids, we have found a lower rDAS value in patients with CC genotype (p = 0.039).This is the peer-reviewed version of the article: Vejnović, D.; Milić, V.; Popović, B.; Damnjanović, T.; Maksimović, N.; Bunjevački, V.; Krajinović, M.; Novaković, I.; Damjanov, N.; Jekić, B. Association of C35T Polymorphism in Dihydrofolate Reductase Gene with Toxicity of Methotrexate in Rheumatoid Arthritis Patients. Expert Opinion on Drug Metabolism & Toxicology 2019, 15 (3), 253–257. [https://doi.org/10.1080/17425255.2019.1563594

Association of dihydrofolate reductase (DHFR)-317AA genotype with poor response to methotrexate in patients with rheumatoid arthritis

Objectives Identifying genetic predictors of methotrexate (MTX) treatment response in patients with rheumatoid arthritis (RA) may have great importance for optimising drug doses required for clinical benefit without toxicity. In a group of 125 RA patients treated with MTX we investigated whether selected polymorphisms in genes relevant for MTX action (aminoimidazole-4-carboxiamide ribonucleotide transformylase, ATIC, and dihydrofolate reductase, DHFR) modulate disease activity and/or have impact on therapy side effects. Methods The efficacy of treatment was estimated both by the disease activity score in 28 joints (DAS28), based on EULAR criteria, and relative DAS28 (rDAS28) score. Adverse drug events (ADEs) were also recorded. RA patients were genotyped using the PCR-RFLP method, followed by an association study between ATIC -129T>G, DHFR -216T>C and DHFR -317A>G polymorphisms and the efficacy and toxicity of MTX. Results According to the EULAR response criteria, 96 RA patients (76.8%) were classified as responders (good/moderate response) and 29 (23.2%) as non-responders (poor response). rDAS28 values ranged from -0.01 to 0.80 (mean value 0.31 +/- 0.19). Among 125 patients enrolled in this study 39 experienced at least one side effect. The DHFR -317AA genotype was associated with the less favourable response (reduction in rDAS28 score, p=0.05). None of the analysed polymorphisms was associated with MTX toxicity. Conclusion RA patients with DHFR-317AA genotype had less favourable response to MTX Further studies in larger patient populations are necessary to confirm the relationship between the analysed polymorphisms and MTX treatment response

Association of the TYMS 3G/3G genotype with poor response and GGH 354GG genotype with the bone marrow toxicity of the methotrexate in RA patients

Purpose Gamma-glutamyl hydrolase (GGH), cyclin D1 (CCND1) and thymidylate synthase (TS) genes encode enzymes that are involved in methotrexate (MTX) action. In a group of 184 RA patients treated with MTX, we have investigated whether selected polymorphisms in these genes modulate MTX efficacy and/or have impact on adverse drug effects (ADEs). Methods The efficacy of the MTX therapy has been estimated using the disease activity score in 28 joints (DAS28-ESR) based on EULAR criteria and relative DAS28 values (rDAS28). All adverse drug events were recorded. Patients were genotyped for selected polymorphisms of the GGH (-354 G>T and 452 C>T), CCND1 (870 A>G) and TYMS (variable number of tandem repeats, VNTR, and G to C substitution of triple repeat, 3R allele) gene. Association studies have been performed between obtained genotypes and the efficacy and toxicity of MTX. Results According to the EULAR response criteria, 146 RA patients (79.3 %) were classified as responders (good/moderate response) and 38 (20.7 %) as nonresponders (poor response). Higher frequency of the TYMS 3 G/3 G genotype has been found among non-responders as compared to individuals with remaining genotypes (p=0.02). ADEs were recorded in 53 patients. Among those patients eight experienced bone marrow toxicity, all of them carried GGH -354GG genotype (p=0.003). No other significant association were observed. Conclusion The 3 G/3 G genotype of the TYMS gene may indicate predisposition of poor response to MTX and GG genotype of GGH -354 T>G polymorphism may have high predictive value for myelosuppression in RA patients

The Virus-Induced Upregulation of the miR-183/96/182 Cluster and the FoxO Family Protein Members Are Not Required for Efficient Replication of HSV-1

Herpes simplex virus 1 (HSV-1) expresses a large number of miRNAs, and their function is still not completely understood. In addition, HSV-1 has been found to deregulate host miRNAs, which adds to the complexity of the regulation of efficient virus replication. In this study, we comprehensively addressed the deregulation of host miRNAs by massive-parallel sequencing. We found that only miRNAs expressed from a single cluster, miR-183/96/182, are reproducibly deregulated during productive infection. These miRNAs are predicted to regulate a great number of potential targets involved in different cellular processes and have only 33 shared targets. Among these, members of the FoxO family of proteins were identified as potential targets for all three miRNAs. However, our study shows that the upregulated miRNAs do not affect the expression of FoxO proteins, moreover, these proteins were upregulated in HSV-1 infection. Furthermore, we show that the individual FoxO proteins are not required for efficient HSV-1 replication. Taken together, our results indicate a complex and redundant response of infected cells to the virus infection that is efficiently inhibited by the virus

The Virus-Induced Upregulation of the miR-183/96/182 Cluster and the FoxO Family Protein Members Are Not Required for Efficient Replication of HSV-1

Herpes simplex virus 1 (HSV-1) expresses a large number of miRNAs, and their function is still not completely understood. In addition, HSV-1 has been found to deregulate host miRNAs, which adds to the complexity of the regulation of efficient virus replication. In this study, we comprehensively addressed the deregulation of host miRNAs by massive-parallel sequencing. We found that only miRNAs expressed from a single cluster, miR-183/96/182, are reproducibly deregulated during productive infection. These miRNAs are predicted to regulate a great number of potential targets involved in different cellular processes and have only 33 shared targets. Among these, members of the FoxO family of proteins were identified as potential targets for all three miRNAs. However, our study shows that the upregulated miRNAs do not affect the expression of FoxO proteins, moreover, these proteins were upregulated in HSV-1 infection. Furthermore, we show that the individual FoxO proteins are not required for efficient HSV-1 replication. Taken together, our results indicate a complex and redundant response of infected cells to the virus infection that is efficiently inhibited by the virus

The Virus-Induced Upregulation of the miR-183/96/182 Cluster and the FoxO Family Protein Members Are Not Required for Efficient Replication of HSV-1

Herpes simplex virus 1 (HSV-1) expresses a large number of miRNAs, and their function is still not completely understood. In addition, HSV-1 has been found to deregulate host miRNAs, which adds to the complexity of the regulation of efficient virus replication. In this study, we comprehensively addressed the deregulation of host miRNAs by massive-parallel sequencing. We found that only miRNAs expressed from a single cluster, miR-183/96/182, are reproducibly deregulated during productive infection. These miRNAs are predicted to regulate a great number of potential targets involved in different cellular processes and have only 33 shared targets. Among these, members of the FoxO family of proteins were identified as potential targets for all three miRNAs. However, our study shows that the upregulated miRNAs do not affect the expression of FoxO proteins, moreover, these proteins were upregulated in HSV-1 infection. Furthermore, we show that the individual FoxO proteins are not required for efficient HSV-1 replication. Taken together, our results indicate a complex and redundant response of infected cells to the virus infection that is efficiently inhibited by the virus