Pharmacogenetic Profiling in High-Risk Soft Tissue Sarcomas Treated with Neoadjuvant Chemotherapy.

Neoadjuvant chemotherapy based on anthracyclines and ifosfamide for high-risk soft tissue sarcomas (STS) of the extremities and trunk is a controversial treatment option. There are substantial interindividual differences in clinical outcomes in patients treated with neoadjuvant chemotherapy. The aim of this study was to evaluate, as biomarkers, polymorphisms in genes encoding drug-metabolizing enzymes, drug transporters, or drug targets and their association with toxicity and survival in STS patients treated with neoadjuvant chemotherapy. We analysed variants in genes involved in anthracycline metabolism (ABCB1, ABCC2, NQO1, CBR3, and SLC22A16) and in ifosfamide catabolism (ALDH1A1) in 79 treated patients. Two genes showed significant association after adjusted multivariate analysis: ABCC2 and ALDH1A1. In patients treated with anthracyclines, ABCC2 rs3740066 was associated with risk of febrile neutropenia (p = 0.031), and with decreased overall survival (OS) (p = 0.024). ABCC2 rs2273697 was associated with recurrence-free survival (RFS) (p = 0.024). In patients treated with ifosfamide, ALDH1A1 rs3764435 was associated with RFS (p = 0.046). Our pharmacogenetic study shows for the first time that variants in genes regulating the metabolism of neoadjuvant chemotherapy may be helpful to predict toxicity and survival benefit in high-risk STS treated with neoadjuvant chemotherapy. Further validation studies are needed to establish their clinical utility.

ABCB1 Genetic Variants as Predictors of Irinotecan-Induced Severe Gastrointestinal Toxicity in Metastatic Colorectal Cancer Patients.

Irinotecan is widely used in the treatment of metastatic colorectal cancer (mCRC) despite its severe toxicities. Toxicity is often associated with the UGT1A1*28/*28 genotype. An explanation for idiopathic toxicity beyond the UGT1A1 biomarker, however, remains a major concern for clinicians. One of the main irinotecan transporters is P-glycoprotein (P-gp), which is a hepatic efflux pump encoded by ABCB1. P-gp is involved in the biliary excretion of irinotecan and its active metabolite SN-38. We aimed to assess whether functional variants in ABCB1 also contribute to identifying patients at risk of toxicity. A cohort of 308 mCRC patients treated with irinotecan-based regimens were genotyped for polymorphisms in ABCB1 (rs1128503, rs2032582, and rs1045642). The effect of these variants and their haplotypes on irinotecan-induced severe toxicity (diarrhea, neutropenia, asthenia, nausea, and mucositis) was assessed. After adjusting for the relevant clinical and pathological parameters in the multivariate analysis, we found rs1128503 was significantly associated with severe diarrhea and mucositis (P=0.014 and P=0.002, respectively). Additionally, rs2032582 was associated with severe mucositis (P<0.001). Our results show that rs1128503 genotyping could help to predict severe gastrointestinal toxicity induced by irinotecan.

Association study of polymorphisms within inflammatory genes and methylation status in treatment response in major depression.

BACKGROUND: Although pharmacogenetics for major depressive disorder (MDD) is gaining momentum, the role of genetics in differences in response to antidepressant treatment is controversial, as they depend on multifactorial and polygenic phenotypes. Previous studies focused on the genes of the serotonergic system, leaving apart other pathological factors such as the inflammatory pathway. The main objective of the study was to assess whether treatment response might be associated with specific inflammation-related genetic variants or their methylation status. METHODS: 41 SNPs in 8 inflammatory genes: interleukin (IL) 1-ß, IL2, IL6, IL6R, IL10, IL18, tumor necrosis factor (TNF)-α and interferon (IFN)-γ were genotyped in 153 patients with MDD, who were evaluated with the Mausdley Staging Method to determine treatment response profiles. Pyrosequencing reactions and methylation quantification were performed in a PyroMark Q24 in 5 selected CpG islands of IL1- ß, IL6 and IL6R. Linear and logistic regression analyses were conducted, including age and gender as covariates using PLINK 1.07. RESULTS: Allelic distribution of IL1- ß rs1143643 was significantly associated with MSM scores (FDR corrected p = 0.04). Allelic distribution of IL6R rs57569414 showed a trend towards significance with MSM scores (p = 0.002; FDR corrected p = 0.07). Haplotype analyses showed associations between allelic combinations of IL1-ß and IL10 with treatment response (FDR corrected p < 0.01). Methylation percentage of treatment responders was only higher in an IL6R CpG island (p < 0.05). CONCLUSIONS: These exploratory findings suggest that IL1-ß and, marginally, IL6R polymorphisms may affect treatment response in major depression. If confirmed, these results may account for the heterogeneous phenotypes of major depression that underlie differences in treatment response.

The role of hypothalamus-pituitary-adrenal genes and childhood trauma in borderline personality disorder.

Current knowledge suggests that borderline personality disorder (BPD) results from the interaction between genetic and environmental factors. Research has mainly focused on monoaminergic genetic variants and their modulation by traumatic events, especially those occurring during childhood. However, to the best of our knowledge, there are no studies on the genetics of hypothalamus-pituitary-adrenal (HPA) axis, despite its vulnerability to early stress and its involvement in BPD pathogenesis. The aim of this study was to investigate the contribution of genetic variants in the HPA axis and to explore the modulating effect of childhood trauma in a large sample of BPD patients and controls. DNA was obtained from a sample of 481 subjects with BPD and 442 controls. Case-control differences in allelic frequencies of 47 polymorphisms in 10 HPA axis genes were analysed. Modulation of genetic associations by the presence of childhood trauma was also investigated by dividing the sample into three groups: BPD with trauma, BPD without trauma and controls. Two FKBP5 polymorphisms (rs4713902-C and rs9470079-A) showed significant associations with BPD. There were also associations between BPD and haplotype combinations of the genes FKBP5 and CRHR1. Two FKBP5 alleles (rs3798347-T and rs10947563-A) were more frequent in BPD subjects with history of physical abuse and emotional neglect and two CRHR2 variants (rs4722999-C and rs12701020-C) in BPD subjects with sexual and physical abuse. Our findings suggest a contribution of HPA axis genetic variants to BPD pathogenesis and reinforce the hypothesis of the modulating effect of childhood trauma in the development of this disorder.

Methotrexate pharmacokinetic genetic variants are associated with outcome in rheumatoid arthritis patients.

BACKGROUND: Methotrexate (MTX) is the most used drug for the treatment of rheumatoid arthritis (RA) although outcome differs among patients. AIM: To evaluate whether polymorphisms in pharmacokinetic genes are associated with outcome in RA patients receiving MTX. PATIENTS & METHODS: We analyzed 28 SNPs in SLC19A1/RFC1, ABCB1, FPGS and GGH genes. RESULTS: We studied 194 RA patients receiving MTX monotherapy. Two FPGS SNPs, rs10987742 and rs10106, were associated with response (p = 0.033 and p = 0.041, respectively). The FPGS rs10106 variant was also associated with MTX survival (p = 0.005) and toxicity (p = 0.021). Three ABCB1 SNPs, rs868755, rs10280623 and rs1858923, were associated with toxicity (p = 0.025, p = 0.048 and p = 0.031, respectively). CONCLUSION: FPGS and ABCB1 genetic variants can influence the outcome in RA patients receiving MTX monotherapy.

An exploratory association study of the influence of noradrenergic genes and childhood trauma in Borderline Personality Disorder.

This study investigated the possible association of 40 polymorphisms within 4 noradrenergic genes with BPD risk and the modulating effect of childhood trauma on these associations in 481 BPD subjects and 442 controls. COMT rs5993882, DBH rs77905 and SLC6A2 rs1814270 showed associations with BPD, which were modulated by childhood trauma. However, none of these findings survived Bonferroni correction. Further investigation is needed to clarify the involvement of these genes in BPD pathogenesis.

HIV-infection, atherosclerosis and the inflammatory pathway: candidate gene study in a Spanish HIV-infected population.

BACKGROUND: Higher prevalence of atherosclerosis and higher cardiovascular risk is observed in HIV-infected individuals. The biological mechanisms underlying these processes are unclear. Several studies have implicated genetic variants in the inflammatory genes in cardiovascular disease and in HIV natural course infection. METHODS & FINDINGS: In this study we have tested the possible association between genetic variants in several inflammatory genes and asymptomatic cardiovascular disease measured by carotid intima media thickness (cIMT) and atherosclerotic plaque presence as dependent variables in 213 HIV-infected individuals. A total of 101 genetic variants in 25 candidate genes have been genotyped. Results were analyzed using Plink and SPSS statistical packages. We have found several polymorphisms in the genes ALOX5 (rs2115819 p = 0.009), ALOX5AP (rs9578196 p = 0.007; rs4769873 p = 0.004 and rs9315051 p = 0.0004), CX3CL1 (rs4151117 p = 0.040 and rs614230 p = 0.015) and CCL5 (rs3817655 p = 0.018 and rs2107538 p = 0.018) associated with atherosclerotic plaque. cIMT mean has been associated with CRP (1130864 p = 0.0003 and rs1800947 p = 0.008), IL1RN (rs380092 p = 0.002) and ALOX5AP (rs3885907 p = 0.02) genetic variants. CONCLUSIONS: In this study we have found modest associations between genetic variants in several inflammatory genes and atherosclerotic plaque or cIMT. Nevertheless, our study adds evidence to the association between inflammatory pathway genetic variants and the atherosclerotic disease in HIV-infected individuals.

Association between methylation of the glucocorticoid receptor gene, childhood maltreatment, and clinical severity in borderline personality disorder.

The hypothalamus-pituitary-adrenal axis (HPA) is essential in the regulation of stress responses. Increased methylation of the promoter region of the glucocorticoid receptor gene (NR3C1) has been described both in subjects with history of childhood trauma and in patients with Borderline Personality Disorder (BPD). However, no data on the possible association between a higher methylation of this gene and clinical severity is available. The aim of this study was to evaluate the association between NR3C1 methylation status, the history of childhood trauma, and current clinical severity in subjects with BPD. A sample of 281 subjects with BPD (diagnosed by SCID-II and DIB-R semi-structured diagnostic interviews) was recruited. Clinical variables included previous hospitalizations, self-injurious behavior, and self-reported history of childhood trauma. DNA was extracted from peripheral blood. The results indicated a significant positive correlation between NR3C1 methylation status and childhood maltreatment (specifically physical abuse). In addition, a positive correlation between methylation status and clinical severity (DIB-R total score and hospitalizations) was observed. These findings suggest that NR3C1 methylation in subjects with BPD may be associated not only with childhood trauma but also with clinical severity, adding new evidence to the involvement of gene-environment interactions in this disorder.

Exploring the interaction between childhood maltreatment and temperamental traits on the severity of borderline personality disorder.

BACKGROUND: Childhood maltreatment and temperamental traits play a role in the development of Borderline Personality Disorder (BPD). The aim of the present study was to assess the involvement and the interrelationship of both factors in the clinical severity of BPD. METHOD: The self-reported history of childhood trauma, psychobiological temperamental traits, and severity of BPD symptoms were evaluated in 130 subjects with BPD. RESULTS: Approximately 70% of the sample reported some form of abuse or neglect. Childhood maltreatment inversely correlated with sociability, but no correlation was observed with the other temperamental traits. The regression model showed that neuroticism-anxiety and aggression-hostility traits, as well as emotional abuse, were risk factors independently associated with the severity of BPD. Sexual abuse was not associated with the severity of the disorder. Finally, the interaction between high neuroticism-anxiety traits and the presence of severe emotional abuse was associated with BPD severity. CONCLUSION: These results suggest that the interaction between temperamental traits and childhood emotional abuse has an influence not only on the development but also on the severity of BPD. Further studies are needed to identify more biological and environmental factors associated with the severity of the disorder.

Farmacogenética de las reacciones adversas a los antipsicóticos en pacientes con esquizofrenia / Pharmacogenetics of antipsychotic adverse effects in patients with schizophrenia

Esta revisión se centra en los conocimientos actuales en el campo de la farmacogenética que tienen relación con las reacciones adversas a los antipsicóticos en pacientes con esquizofrenia. En el momento actual hay numerosas investigaciones que han intentado determinar variantes genéticas que permitan predecir el riesgo individual de padecer efectos secundarios al tratamiento con antipsicóticos. Múltiples estudios determinan que polimorfismos de las enzimas del citocromo P450 y de los receptores dopaminérgicos pueden estar relacionados con un mayor riesgo de trastornos del movimiento inducidos por antipsicóticos. Por otro lado, tanto el sistema serotoninérgico como la leptina se han relacionado con el control del apetito, y variantes del receptor 5-HT2C y del gen de la leptina pueden estar asociadas al aumento de peso en el contexto del tratamiento con estos fármacos. Estudios centrados en el riesgo de agranulocitosis con clozapina han concluido que variantes del sistema mayor de histocompatibilidad pueden ser responsables de un incremento del riesgo de aparición de esta reacción adversa (AU)

This review focuses on the current knowledge on pharmacogenetics related to adverse reactions to antipsychotics in patients with schizophrenia. Numerous studies have attempted to identify genetic variants that predict individual risk of side effects during antipsychotic treatment. Several of these studies have determined that polymorphisms of cytochrome P450 enzymes and dopamine receptors may be related to an increased risk of movement disorders induced by antipsychotics. On the other hand, the serotonergic and leptin systems can regulate food intake, and polymorphisms in the 5-HT2C and leptin genes have been associated with antipsychotic-induced weight gain. Several studies have investigated the risk of agranulocytosis during clozapine treatment, and concluded that genetic variants of the major histocompatibility complex may be related with and increased risk of agranulocytosis (AU)

Effect of FTO, SH2B1, LEP, and LEPR polymorphisms on weight gain associated with antipsychotic treatment.

Weight gain is one of the major adverse effects of antipsychotics. Although mechanisms remain unclear, genetic susceptibility has become increasingly attractive as a potential mechanism that could explain a significant part of interindividual variability. Most investigations have explored genes related with the mechanism of action of antipsychotic drugs. An alternative approach to investigate the role that genetic factors play in weight gain secondary to antipsychotic treatment is to study those genetic variants that have been found associated with obesity. The aim of this study was to determine whether the fat mass and obesity-associated gene (FTO) rs9939609 variant, the single nucleotide polymorphism that has shown the strongest association with common obesity in different populations, influences weight gain during the first year of antipsychotic treatment. We investigated also the genetic variants in other 3 strong candidates genes involved in the leptin-signaling pathway including leptin, leptin receptor, and Src homology 2. We carried out a prospective study on 239 patients with first-episode psychosis. Two hundred five patients completed the follow-up at 1 year (85.8%). Before antipsychotic treatment, the homozygous subjects for the risk allele A of the FTOrs9939609 variant had a higher body mass index at baseline (24.2 T 3.8 kg/m²) than the AT/TT group (22.82 T 3.3 kg/m2; F = 5.744; P = 0.018). After 1 year, the magnitude of weight increase was similar in the 3 genotypes defined by the rs9939609 variant. These results suggest that the pharmacological intervention accompanied by changes in energy intake and expenditure could suppress the genetic susceptibility conferred by the FTO genotype. None of the other single nucleotide polymorphisms evaluated were associated with weight gain during the first 12 months of antipsychotic therapy.

Serotonin transporter polymorphisms and early response to antipsychotic treatment in first episode of psychosis.

There is substantial evidence suggesting that individual variability in antipsychotic treatment response could be genetically determined. Variations in several serotonin transporter (5-HTT) gene polymorphisms have been associated with antipsychotic response among chronic patients with schizophrenia, although their implication in early response among first-episode patients remains unclear. Two polymorphisms in the 5-HTT gene (a 44 bp insertion/deletion in the promoter region and the functional polymorphism rs25531) were genotyped in a sample of 147 drug-naïve patients experiencing a first episode of a non-affective psychosis. Early (6 weeks) response to antipsychotic treatment with haloperidol, olanzapine or risperidone was assessed with the Brief Psychiatric Rating Scale, the Scale for the Assessment of Positive Symptoms, and the Scale for the Assessment of Negative Symptoms. No clear association was found between the rs25531 variant and treatment response. However, significant associations were observed between 5-HTT-LPR variants and early negative symptom response among first-episode patients with psychosis. Our results suggest a minor contribution to antipsychotic drug response of genetic alterations in the 5-HTT gene.

Catechol-O-methyltransferase Val158Met polymorphism and clinical characteristics in first episode non-affective psychosis.

Catechol-O-methyltransferase (COMT) Val158Met polymorphism has been identified as a potential etiologic factor in schizophrenia. It has been proposed that this polymorphism could be associated with specific clinical markers. The aim of the study was to evaluate the influence of COMT Val158Met polymorphism genotype in the phenotypic expression of first episode psychosis at onset. Age of onset, DUP, SANS, and SAPS (positive, disorganized, and negative dimensions) were studied in 169 Caucasian drug-naïve patients with a first-episode of non-affective psychosis. The COMT Val158Met polymorphism was typed using PCR amplification of the relevant region followed by digestion with NlaIII and electrophoresis. A multivariate ANCOVA was performed with COMT and gender as independent variables. Patients with Val/Val genotype had significantly higher levels of SANS negative dimension scores (F: 3.539; P = 0.031) and had a younger age of onset (F: 4.649; P = 0.011) than Met carriers. Our findings suggest that the Val allele is associated with onset phenotypic features related to a poor prognosis of the illness. These data would indicate that COMT genotype may have a role in the etiological model for schizophrenia and other psychotic disorders.

Association between the interleukin-1 receptor antagonist gene and negative symptom improvement during antipsychotic treatment.

The contribution of immune system to schizophrenia has been an important area of focus in schizophrenia research. Several genetic variants in the cytokine system have been associated with the pathogenesis of schizophrenia. The purpose of this study was to determine whether a pharmacogenetic relationship exists between a variable number of tandem repeats (VNTR) polymorphism in the interleukin-1 receptor antagonist gene (IL-1RN) and clinical improvement during antipsychotic treatment in patients with a first non-affective psychotic episode. One hundred and fifty-four subjects presenting with a first non-affective psychotic episode were randomly assigned to treatment with haloperidol, risperidone, or olanzapine and rated with the Brief Psychiatric Rating Scale (BPRS), the Scale for the Assessment of Negative Symptoms (SANS) and the Scale for the Assessment of Positive Symptoms (SAPS) both at baseline and after 6 weeks of treatment. A control sample of 336 blood bank donors was also included. No differences in genotype or allele distributions were found between patients and controls. However, after controlling for baseline SANS scores, the genotype in the VNTR polymorphism in the IL-1RN gene significantly predicted negative symptom improvement, accounting for approximately 7% of the variance (F = 5.23, df = 2, P = 0.006). The mean decrease in SANS scores was 58% for the IL-1RN* 2/2, 44% for the IL-1RN* 1/2, and 14% for the IL-1RN* 1/1 subjects, respectively. These results suggest that the VNTR polymorphism in the IL-1RN gene may be a useful predictor of negative symptom improvement in schizophrenic patients treated with antipsychotic drugs.

The -1438A/G polymorphism in the 5-hydroxytryptamine type 2A receptor gene affects promoter activity.

BACKGROUND: The -1438A/G single nucleotide polymorphism (SNP) lies just upstream of two alternative promoters for the 5-hydroxytryptamine type 2A (5-HT2A) receptor gene (HTR2A) and is in strong linkage disequilibrium with the 102T/C SNP. Both SNPs are associated with numerous psychiatric disorders and related phenotypes. A possible functional affect of the -1438A/G SNP might underlie associations of both linked SNPs with these neuropsychiatric disorders. A prior investigation into affects of this SNP on promoter function, lacking the more downstream promoter, found no significant difference with a reporter gene assay. METHODS: To investigate possible functional effects of -1438A/G on either promoter, two different reporter gene assays were used in three cell lines. RESULTS: Promoter activity was consistently detected that, in the presence of the SV40 enhancer, was significantly greater in the presence of the A allele relative to the G allele but only in cell lines that express endogenous HTR2A, suggesting that transcriptional factor(s) and the presence of both promoters might be necessary to elicit this effect. CONCLUSIONS: These findings show that the -1438A/G SNP has the potential to modulate HTR2A promoter activity and might be the functional variant responsible for the associations of both SNPs with many neuropsychiatric phenotypes.

El futuro de la farmacogenética y sus aplicaciones en psiquiatría / The future of pharmacogenetics and its applications to psychiatry

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