Influence of genetic variants and post transcriptional factors on imatinib transporters as determinants of the pharmacological response

Introduction – Although imatinib (IM) is a recognized gold standard in chronic myeloid leukemia (CML) therapy, resistance has emerged in a significant proportion of patients. Aim – The aim of this study was: (1) to investigate the role of genetic variants in genes encoding for IM transporters, as candidate of IM responsiveness and (2) to test the influence of miRNAs on IM response, focusing on efflux transporters. Methods – As a first step, a panel of polymorphisms (SNPs) was genotyped in a subgroup population of 189 patients enrolled in the Tyrosine Kinase Inhibitor Optimization and Selectivity (TOPS) trial. The association with cytogenetic response and molecular response (MR) was assessed for each SNP. As a second step, an in vitro IM-resistant model (K-562 CML cell line) was established. miRNAs profiles were analyzed using Taqman arrays and in silico search was performed for miRNAs deregulated after IM treatment. mRNA and protein expression were quantified using TaqMan realtime PCR and Western blotting, respectively. Results – (1) Among Caucasian patients, ABCB1 rs60023214 significantly correlated with complete MR (P = 0.005). Concerning SNPs combination in IM uptake transporters, the associations with treatment outcomes were statistically significant for both major and complete MR (P = 0.005 and P = 0.01, respectively). (2) ABCB1 protein was not expressed under any conditions of treatment, differently from ABCG2. Two deregulated miRNAs, namely miR-212 and miR-328, were identified to be inversely correlated with ABCG2 (r2= 0.57; p=0.03 and r2=0.47; p=0.06, respectively). Experiments of loss and gain of function confirmed the functional influence of these miRNAs on ABCG2. Conclusion – The multiple candidate gene approach identified single and combination of SNPs that can be proposed as predictor of IM response. The in vitro study suggested that IM resistance could be mediated by miRNA-dependent mechanism. Further studies are needed to validate these preliminary findings.

L'Amiloidosi transtiretino correlata ereditaria: profilo clinico, fisiopatologico e storia naturale

Background. Hereditary transthyretin (TTR)-related amyloidosis (ATTR) is mainly considered a neurologic disease. We assessed the phenotypic and genotypic spectrum of ATTR in a non-endemic, Caucasian area and evaluated prevalence, genetic background and disease profile of cases with an exclusively cardiac phenotype, highlighting possible hints for the differential diagnosis with hypertrophic cardiomyopathy (HCM) and senile systemic amyloidosis (SSA) Methods and Results. In this Italian multicenter study, 186 patients with ATTR were characterized at presentation. Thirty patients with SSA and 30 age-gender matched HCM patients were used for comparison. Phenotype was classified as: exclusively cardiac (n= 31, 17%), exclusively neurologic (n= 46, 25%), mixed cardiac/neurologic (n=109, 58%). Among the 8 different mutations responsible for an exclusively cardiac phenotype, Ile68Leu was the most frequent (23/31). Five patients with an exclusively cardiac phenotype developed mild abnormalities at neurological examination but no symptoms during a 36 [14−50] month follow-up. Exclusively cardiac phenotype was characterized by male gender, age > 65 years, heart failure symptoms, concentric left ventricular (LV) “hypertrophy” and moderately depressed LV ejection fraction. This profile was similar to SSA but relatively distinct from HCM. Compared to patients with a mixed phenotype, patients with a exclusively cardiac phenotype showed a more pronounced cardiac involvement on both echocardiogram and ECG. Conclusion. A clinically relevant subset of Caucasian ATTR patients present with an exclusively cardiac phenotype, mimicking HCM or SSA. Echocardiographic and ECG findings are useful to differentiate ATTR from HCM but not from SSA. The role of liver transplantation in these patients is questionable.

CYP17A1 polymorphisms and clinical outcome of patients with metastatic castration-resistant prostate cancer treated with abiraterone

Background. Abiraterone acetate is a potent inhibitor of cytochrome P450 17 α-hydrolase (CYP17A1) that causes a reduction in the synthesis of testosterone in the adrenal glands, testes and tumor microenvironment. Blocking androgen production, abiraterone has been shown to prolong progression-free survival (PFS) and overall survival (OS) in patients with metastatic castration-resistant prostate cancer (CRPC) previously submitted to chemotherapy. The aim of our study was to verify the role of single nucleotide polymorphisms (SNPs) in predicting clinical outcome in CRPC patients treated with abiraterone after chemotherapy. Methods. We analyzed 48 CRPC consecutive patients treated with abiraterone after at least one chemotherapeutic regimen with docetaxel. DNA was extracted from peripheral blood and genotyped for four polymorphisms in the CYP17A1 gene (rs743572, rs10883783, rs17115100, rs284849). PFS and OS survival curves were used to identify statistical associations between haplotypes and clinical outcome. Results. Forty-eight Caucasian patients with metastatic CRPC treated with abiraterone were genotyped for polymorphisms in the CYP17A1 gene. All samples were evaluable for both sequencing and TaqMan Genotyping assay. The CRPC patients treated with abiraterone had a median PFS and OS of 7.6 months (95% CI: 4.3-10.5) and 17.6 months (95% CI: 10.5-19.0), respectively Statistical analyses highlighted a difference approaching statistical significance (log-rank test p = 0.0534) between rs10883783 and PFS. Other polymorphisms were not associated with a benefit from treatment with abiraterone. Conclusions. In our case series of 48 treated patients, rs10883783 only was identified as a possible predictive marker, results showing a trend toward statistical significance. Further analysis of this polymorphism is needed in larger series of patients to confirm our findings.

Adulthood with Turner Syndrome: Quality of life, psychosocial adjustment and clinical management in 70 Italian women

Abstract Background: Turner syndrome (TS) is a chromosomal abnormality (total or partial absence of one of the sexual chromosomes in some or all cells of the body), which affects approximately 1:2000 female. Principal characteristics are short stature and gonadal disgenesis. Clinical management consist of Growth Hormone (GH) treatment and oestrogen replacement therapy (HRT), to induce development of secondary characteristics and to avoid the sequelae of oestrogen deficiency. Aim of the study: To assess clinical management, quality of life (QoL) and general psychosocial adjustment of women with TS. Population: 70 adult Caucasian females with TS (mean age: 27.8, ± 7.6; range 18-48 y.). Setting: Specialist service for Rare Disease care, University Hospital. Methods: Subjects were required to fill in questionnaires collecting ASR, WHOQOL, and 8 open questions. Data were compared with those of the Italian population or to those collected in a comparison group (70 healthy females, mean age: 27.9, ±7.3, range 21-48 y.). Results: Women with TS are educated as well as the Italian Population, but they have a less successful professional life. They show good QoL in general, but they appeared less satisfied in social area. They had statistically higher scores than the comparison group for depression, anxiety and withdrawal. Are less involved in a love relationship. Diagnosis communication was mostly performed by doctors or parents, satisfaction was higher when information was given by parents. Main preoccupation about TS are infertility, feeling of being different and future health problem. Conclusions: Italian people with TS were generally well adapted and have a good QoL, but lived more often with parents and show impaired sentimental and sexual life. They have higher degree of psychological distress compared to a comparison group. Psychological intervention should firstly address parents in order to encourage an open communication on diagnosis issues and on sexual education.