First study on iron complexes in blood and organ samples from thalassaemic and normal laboratory mice using Mössbauer spectroscopy.

Measurements of iron complexes and iron stores in the body are crucial for evaluation and management of chelation therapy targeted against iron accumulation or overload in blood and organs. In this work, blood and tissue samples from one normal and one thalassaemic laboratory mouse were studied using 57Fe Mössbauer spectroscopy at 78 K for the first time. In contrast to human patients, these laboratory mice did not receive any medical treatment, thus the iron components present in the samples are not altered from their natural state. The Mössbauer spectra of blood, liver and spleen samples of the thalassaemic mouse were found to differ in shape and iron content compared with corresponding spectra of the normal mouse. These results demonstrate a basis for further exploitation of the thalassaemic mouse model to study thalassaemia and its treatment in more detail using Mössbauer spectroscopy.

Development of a Predictive Pharmacophore Model and a 3D-QSAR Study for an in silico Screening of New Potent Bcr-Abl Kinase Inhibitors.

Chronic myelogenous leukemia (CML) is a myeloproliferative disorder, characterized, in most cases, by the presence of the Bcr-Abl fusion oncogene. Bcr-Abl is a constitutively active tyrosine kinase that is responsible for the malignant transformation. Targeting the Bcr-Abl kinase is an attractive treatment strategy for CML. First and second generation Bcr-Abl inhibitors have focused on targeting the ATP-binding domain of the kinase. Mutations in that region are relatively resistant to drug manipulation. Therefore, non-ATP-competitive agents have been recently developed and tested. In the present study, in an attempt to aid the design of new chemotypes with enhanced cytotoxicity against K562 cells, 3D pharmacophore models were generated and 3D-QSAR CoMFA and CoMSIA studies were carried out on the 33 novel Abl kinase inhibitors (E)-α-benzylthio chalcones synthesized by Reddy et al. A five-point pharmacophore with a hydrogen bond acceptor, two hydrophobic groups and two aromatic rings as pharmacophore features, and a statistically significant 3D-QSAR model with excellent predictive power were developed. The pharmacophore model was also used for alignment of the 33 compounds in a CoMFA/CoMSIA analysis. The contour maps of the fields of CoMFA and CoMSIA models were utilized to provide structural insight into how these molecules promote their toxicity. The possibility of using this model for the design of drugs for the treatment of β-thalassemia and sickle cell disease (SCD), since several Bcr-Abl inhibitors are able to promote erythroid differentiation and γ-globin expression in CML cell lines and primary erythroid cells is discussed.

Thalassemia and its relevance to personalized medicine.

Thalassemias are the most common monogenic gene disorders in the world. Patients present with a wide variability of clinical phenotypes ranging from severe phenotype (ß-thalassemia major) to a very mild, almost symptomless, condition. This variability is owing to the presence of a large number of genetic modifiers affecting the disease. Patients are treated with blood transfusions and iron chelation therapy. Pharmacological therapies have varying degrees of success depending on the genetic modifiers of the disease present in the patients. Studies undertaken to identify all the modifiers that affect ß-thalassemia will lead to more appropriate genetic counseling during prenatal diagnosis and enable targeted and personalized treatment regimens for patients in the future.

The impact of genotype on endocrine complications in thalassaemia major.

BACKGROUND: The clinical severity in thalassaemia major (TM) depends on the underlying mutations of the beta-globin gene and the degree of iron overload. OBJECTIVE: The aim of the study was to investigate the impact of genotype on the development of endocrine complications in TM in our center. SUBJECTS AND METHODS: 126 (62 males, 64 females) thalassaemic patients of Greek Cypriot origin with a mean age of 31.2 (17-68) yr were included in the study. All patients, who were on the standard treatment protocol, were subsequently divided into two groups according to their genotype, group A (92): TM with no mitigating factor and group B (34): TM carrying one or more mitigating factors in the beta- and/or alpha-globin genes. Iron overload calculation was based on the amount of red cell consumption and the mean ferritin level over a 12-year period. Statistical analysis was performed with the SPSS program. RESULTS: Patients in group A, who were consuming larger amounts of blood on transfusions, were more likely to develop hypogonadism (P = 0.001) compared with patients in group B, despite their similar mean ferritin levels. The incidence of other endocrinopathies (short stature, hypothyroidism, and diabetes mellitus) was similar in the two groups. The prevalence of hypothyroidism in splenectomized patients was significantly higher (P = 0.005), whereas the presence of hypogonadism, impaired glucose homeostasis and insulin resistance, although more frequent, was not statistically significant. The clinical severity of TM had no impact on bone mineral density (BMD) in both men and women. BMD was only influenced by gonadal function. CONCLUSIONS: This study demonstrates that the underlying genetic defect in TM is a contributing factor for gonadal dysfunction, because the patients with the more severe defects have a greater rate of iron loading through higher red cell consumption.

The impact of iron overload and genotype on gonadal function in women with thalassaemia major.

OBJECTIVE: The purpose of this study is to evaluate the impact of chronic iron overload and genotype on gonadal function in women with thalassaemia major. PATIENTS AND METHODS: The study population consists of 101 women aged 15-48 years who were treated between 1981 and 1999. These women were divided into two groups according to their genotype: [A=no modifying genetic factor and B=presence of modifying factors], and into four groups according to their menstrual history: NM (normal menstruation), OLM (oligomenorrhea), PA (primary amenorrhea), and SA (secondary amenorrhea). RESULTS: Women with NM maintained eumenorrhoea for 14.62 years, whereas those with SA did so for 6.94 years. The serial values of both FSH and LH after stimulation with GnRH were lower in women with SA and PA (p<0.05) compared to women with OLM and NM. The average value of the minimum, mean and maximum ferritin levels over a period of 20 years displayed an increasing trend from women with NM to those with SA and PA. The lower levels of ferritin in women in Group A did not protect them from developing SA. In addition women with SA, who belong to Group A, had a shorter duration of eumenorrhoea compared to the ones with SA who belong to Group B. CONCLUSIONS: Although the pathogenesis of gonadal dysfunction in thalassaemia is known to be the consequence of iron overload, this study demonstrates that genotype acts as an independent variable, contributing to the development of SA in thalassaemic women.