@article {8319, title = {Thiopurine Biotransformation and Pharmacological Effects: Contribution of Oxidative Stress.}, journal = {Curr Drug Metab}, volume = {17}, year = {2016}, month = {2016}, pages = {542-9}, abstract = {

BACKGROUND: Thiopurine antimetabolites are important agents for the treatment of severe diseases, such as acute lymphoblastic leukemia and inflammatory bowel disease. Their pharmacological actions depend on biotransformation into active thioguanine-nucleotides; intracellular metabolism is mediated by enzymes of the salvage pathway of nucleotide synthesis and relies on polymorphic enzymes involved in thiopurines{\textquoteright} catabolism such as thiopurine-S-methyl transferase. Given the enzymes involved in thiopurines{\textquoteright} metabolism, it is reasonable to hypothesize that these drugs are able to induce significant oxidative stress conditions, possibly altering their pharmacological activity.

METHODS: A systemic search of peer-reviewed scientific literature in bibliographic databases has been carried out. Both clinical and preclinical studies as well as mechanistic studies have been included to shed light on the role of oxidative stress in thiopurines{\textquoteright} pharmacological effects.

RESULTS: Sixty-nine papers were included in our review, allowing us to review the contribution of oxidative stress in the pharmacological action of thiopurines. Thiopurines are catabolized in the liver by xanthine oxidase, with potential production of reactive oxidative species and azathioprine is converted into mercaptopurine by a reaction with reduced glutathione, that, in some tissues, may be facilitated by glutathione- S-transferase (GST). A clear role of GSTM1 in modulating azathioprine cytotoxicity, with a close dependency on superoxide anion production, has been recently demonstrated. Interestingly, recent genome-wide association studies have shown that, for both azathioprine in inflammatory bowel disease and mercaptopurine in acute lymphoblastic leukemia, treatment effects on patients{\textquoteright} white blood cells are related to variants of a gene, NUDT15, involved in biotransformation of oxidated nucleotides.

CONCLUSIONS: Basing on previous evidences published in literature, oxidative stress may contribute to thiopurine effects in significant ways that, however, are still not completely elucidated.

}, issn = {1875-5453}, author = {Pelin, Marco and De Iudicibus, Sara and Londero, Margherita and Spizzo, Riccardo and Dei Rossi, Sveva and Martelossi, Stefano and Ventura, Alessandro and Decorti, Giuliana and Stocco, Gabriele} } @article {3524, title = {TNF-α SNP rs1800629 and risk of relapse in childhood acute lymphoblastic leukemia: relation to immunophenotype.}, journal = {Pharmacogenomics}, volume = {15}, year = {2014}, month = {2014 Apr}, pages = {619-27}, abstract = {

AIM: In the AIEOP-BFM ALL (Associazione Italiana Ematologia Oncologia Pediatrica-Berlin Frankfurt M{\"u}nster acute lymphoblastic leukemia) 2000 protocol, 70\% of relapsed patients had favorable prognostic features and fell within less intensive polychemotherapeutic regimens, suggesting the need for better assessing lower risk stratification.

MATERIALS \& METHODS: A novel two-phase study design selected 614 children to be genotyped for TNF-α SNP rs1800629 (-308G>A). A weighted Cox model was applied to evaluate the SNP effect on hazard of relapse, adjusting for immunophenotype, risk group, age and gender and including interaction terms.

RESULTS: Significant interaction was found with immunophenotypes (p = 0.0007, with minor allele genotypes being adverse genetic markers in B-cell acute lymphoblastic leukemia and protective ones in T-cell acute lymphoblastic leukemia), and also with risk protocols (p = 0.0041, with minor allele genotypes as prognostic factor of relapse for standard risk patients [only one T-cell acute lymphoblastic leukemia in the subgroup analyzed]).

CONCLUSION: The presence of at least one A allele in TNF-α SNP rs1800629 should suggest a closer monitoring in B-cell acute lymphoblastic leukemia standard risk patients.

}, keywords = {Adolescent, Antineoplastic Agents, Child, Child, Preschool, Drug Resistance, Neoplasm, Female, Genotype, Humans, Infant, Leukemia, Lymphocytic, Chronic, B-Cell, Male, Phenotype, Precursor Cell Lymphoblastic Leukemia-Lymphoma, Precursor T-Cell Lymphoblastic Leukemia-Lymphoma, Recurrence, Risk Assessment, Steroids, Tumor Necrosis Factor-alpha}, issn = {1744-8042}, doi = {10.2217/pgs.13.249}, author = {Franca, Raffaella and Rebora, Paola and Athanasakis, Emmanouil and Favretto, Diego and Verzegnassi, Federico and Basso, Giuseppe and Tommasini, Alberto and Valsecchi, Maria Grazia and Decorti, Giuliana and Rabusin, Marco} } @article {1654, title = {Targeting farnesyl-transferase as a novel therapeutic strategy for mevalonate kinase deficiency: in vitro and in vivo approaches.}, journal = {Pharmacol Res}, volume = {61}, year = {2010}, month = {2010 Jun}, pages = {506-10}, abstract = {

Mevalonate kinase deficiency (MKD) is a rare inborn auto-inflammatory disease due to the impairment of the pathway for the biosynthesis of cholesterol and non-sterol isoprenoids. The shortage of isoprenoids compounds and in particular of geranylgeranylpyrophosphate (GGPP) was recently associated to the MKD characteristic inflammatory attacks. The aim of this study is to demonstrate that the normalization of the mevalonate pathway intermediates levels and in particular of GGPP, through the specific inhibition of farnesyl-transferase (FT) with Manumycin A could ameliorate the inflammatory phenotype of MKD patients. The effect of Manumycin A was first evaluated in MKD mouse and cellular models, chemically obtained using the aminobisphosphonate alendronate (ALD), and then in monocytes isolated from 2 MKD patients. Our findings were compared to those obtained by using natural exogenous isoprenoids (NEIs). Manumycin A was able to significantly reduce the inflammatory marker serum amyloid A in ALD-treated Balb/c mice, as well as IL-1 beta secretion in ALD-monocytes and in MKD patients. These results clearly showed that, through the inhibition of FT, an increased number of mevalonate pathway intermediates could be redirected towards the synthesis of GGPP diminishing the inflammatory response. The importance in limiting the shortage of GGPP was emphasized by the anti-inflammatory effect of NEIs that, due to their biochemical structure, can enter the MKD pathway. In conclusion, manumycin A, as well as NEIs, showed anti-inflammatory effect in MKD models and especially in MKD-monocytes, suggesting novel approaches in the treatment of MKD, an orphan disease without any efficacious treatment currently available.

}, keywords = {Adult, Animals, Anti-Inflammatory Agents, Cells, Cultured, Child, Preschool, Enzyme Inhibitors, Farnesyltranstransferase, Female, Humans, Male, Mevalonate Kinase Deficiency, Mevalonic Acid, Mice, Mice, Inbred BALB C, Monocytes, Polyenes, Polyisoprenyl Phosphates, Polyunsaturated Alkamides, Young Adult}, issn = {1096-1186}, doi = {10.1016/j.phrs.2010.02.012}, author = {De Leo, Luigina and Marcuzzi, Annalisa and Decorti, Giuliana and Tommasini, Alberto and Crovella, Sergio and Pontillo, Alessandra} }