Effects on erythroid differentiation of platinum(II) complexes of synthetic bile acid derivatives

Pharmacogenomics of Drugs Used in β-Thalassemia and Sickle-Cell Disease: From Basic Research to Clinical Applications

In this short review we have presented and discussed studies on pharmacogenomics (also termed pharmacogenetics) of the drugs employed in the treatment of β-thalassemia or Sickle-cell disease (SCD). This field of investigation is relevant, since it is expected to help clinicians select the appropriate drug and the correct dosage for each patient. We first discussed the search for DNA polymorphisms associated with a high expression of γ-globin genes and identified this using GWAS studies and CRISPR-based gene editing approaches. We then presented validated DNA polymorphisms associated with a high HbF production (including, but not limited to the HBG2 XmnI polymorphism and those related to the BCL11A, MYB, KLF-1, and LYAR genes). The expression of microRNAs involved in the regulation of γ-globin genes was also presented in the context of pharmacomiRNomics. Then, the pharmacogenomics of validated fetal hemoglobin inducers (hydroxyurea, butyrate and butyrate analogues, thalidomide, and sirolimus), of iron chelators, and of analgesics in the pain management of SCD patients were considered. Finally, we discuss current clinical trials, as well as international research networks focusing on clinical issues related to pharmacogenomics in hematological diseases.

Hemoglobin F (HbF) inducers; History, Structure and Efficacies

Inherited beta-thalassemia is a major disease caused by irregular production of hemoglobin through reducing beta-globin chains. It has been observed that increasing fetal hemoglobin (HbF) production improves symptoms in the patients. Therefore, an increase in the level of HbF has been an operative approach for treating patients with beta-thalassemia. This review represents compounds with biological activities and pharmacological properties that can promote the HBF level and therefore used in the β-thalassemia patients' therapy. Various natural products with different mechanisms of action can be helpful in this medication cure. Clinical trials were efficient in improving the signs of patients. Association of in vivo, and in vitro studies of HbF induction and γ-globin mRNA growth displays that in vitro experiments could be an indicator of the in vivo response. The current study shows that; (a) HbF inducers can be grouped in several classes based on their chemical structures and mechanism of actions; b) According to several clinical trials, well-known drugs such as hydroxyurea and decitabine are useful HbF inducers; (c) The cellular biosensor K562 carrying genes under the control of the human γ-globin and β-globin gene promoters were applied during the researches; d) New natural products and lead compounds were found based on various studies as HbF inducers.

A new amido-phosphine of dichloroacetic acid as an active ligand for metals of pharmaceutical interest. Synthesis, characterization and tests of antiproliferative and pro-apoptotic activity

We herein describe the synthesis and characterization of the new amido-phosphinic ligand 3,7‑bis(dichloroacetyl)‑1,3,7‑triaza‑5‑phosphabicyclo[3.3.1]nonane (DCP), a derivative of dichloroacetic acid (DCA), whose ability to reverse the suppressed mitochondrial apoptosis in cancer cells is known. DCP was obtained by a double N-acylation of PTA (1,3,5‑triaza‑7‑phosphaadamantane) occurring with loss of CH₂, in appropriate conditions_. Due to the hindered rotation around the amidic CN bonds, three rotameric forms of DCP were observed, whose ratio in solution was dependent on the solvent, while the X-ray crystal structure of DCP showed an opposite orientation of the two amidic carbonyl groups (anti rotamer). The lipophilic, air and thermally stable DCP was found able to act regiospecifically as a P-donor ligand toward soft metal ions. By ligand substitution on appropriate precursors, we obtained the complexes 1-9, where proapoptotic DCA is associated with metal ions of known cytotoxic activity on cancer cells (Pt²⁺, Pd²⁺, Ru²⁺, Re⁺, Au⁺). The antiproliferative activity of DCP and its complexes was tested in vitro, in comparison with cisplatin, on three human tumor cell lines: A2780 (ovarian cisplatin-sensitive), A2780cis (ovarian cisplatin-resistant) and K562 (erythroleukemic). The results showed that the simultaneous presence of DCP (containing two residues of proapoptotic DCA) and Pt(II) produces the best performances with respect to non-platinum complexes. Experiments of pro-apoptotic activity indicated that the antiproliferative activity of the most active DCP-Pt(II) complexes is associated with induction of apoptosis.

Recent trends in the gene therapy of β-thalassemia

The β-thalassemias are a group of hereditary hematological diseases caused by over 300 mutations of the adult β-globin gene. Together with sickle cell anemia, thalassemia syndromes are among the most impactful diseases in developing countries, in which the lack of genetic counseling and prenatal diagnosis have contributed to the maintenance of a very high frequency of these genetic diseases in the population. Gene therapy for β-thalassemia has recently seen steadily accelerating progress and has reached a crossroads in its development. Presently, data from past and ongoing clinical trials guide the design of further clinical and preclinical studies based on gene augmentation, while fundamental insights into globin switching and new technology developments have inspired the investigation of novel gene-therapy approaches. Moreover, human erythropoietic stem cells from β-thalassemia patients have been the cellular targets of choice to date whereas future gene-therapy studies might increasingly draw on induced pluripotent stem cells. Herein, we summarize the most significant developments in β-thalassemia gene therapy over the last decade, with a strong emphasis on the most recent findings, for β-thalassemia model systems; for β-, γ-, and anti-sickling β-globin gene addition and combinatorial approaches including the latest results of clinical trials; and for novel approaches, such as transgene-mediated activation of γ-globin and genome editing using designer nucleases.

C(5) modified uracil derivatives showing antiproliferative and erythroid differentiation inducing activities on human chronic myelogenous leukemia K562 cells

The K562 cell line has been proposed as a useful experimental system to identify anti-tumor compounds acting by inducing terminal erythroid differentiation. K562 cells exhibit a low proportion of hemoglobin-synthesizing cells under standard cell growth conditions, but are able to undergo terminal erythroid differentiation when treated with a variety of anti-tumor compounds. In this paper we report a screening study on a set of different modified C(5) uracil derivatives for the evaluation of their antiproliferative effect in connection with erythroid differentiation pathways, and for defining a new class of drug candidates for the treatment of chronic myelogenous leukemia. Activity of the derivatives tested can be classified in two effect: an antiproliferative effect linked to a high level of erythroid differentiation activity and an antiproliferative effect without activation of gamma globin genes The highest antiproliferative effect and erythroid induction was shown by compound 9, a thymine derivative bearing a n-octyl chain on nitrogen N(1), whereas thymine did not show any effect, suggesting the importance of the linear alkyl chain in position N(1). To our knowledge this compound should be considered among the most efficient inducers of erythroid differentiation of K562 cells. This work is the starting point for the quest of more effective and specific drugs for the induction of terminal erythroid differentiation, for leading new insights in the treatment of neoplastic diseases with molecules acting by inducing differentiation rather than by simply exerting cytotoxic effects.

Erythroid induction of chronic myelogenous leukemia K562 cells following treatment with a photoproduct derived from the UV-A irradiation of 5-methoxypsoralen

Induction of terminal erythroid differentiation can be an efficient strategy to inhibit proliferation of chronic myelogenous leukemia cells. Psoralens, well-known photo-chemotherapeutic agents, were found to be efficient at inducing erythroid differentiation of K562 cells, an in vitro cell line isolated from the pleural effusion of a patient with chronic myelogenous leukemia in blast crisis. The effects of crude pre-irradiated solutions of 5-methoxypsoralen on erythroid differentiation of human leukemic K-562 cells were evaluated. The major photoproduct was characterized and analyzed, and it was found to induce erythroid differentiation of K562 cells and inhibit NF-kappaB/DNA interactions.

Fetal Hemoglobin Inducers from the Natural World: A Novel Approach for Identification of Drugs for the Treatment of {beta}-Thalassemia and Sickle-Cell Anemia

The objective of this review is to present examples of lead compounds identified from biological material (fungi, plant extracts and agro-industry material) and of possible interest in the field of a pharmacological approach to the therapy of beta-thalassemia using molecules able to stimulate production of fetal hemoglobin (HbF) in adults. Concerning the employment of HbF inducers as potential drugs for pharmacological treatment of beta-thalassemia, the following conclusions can be reached: (i) this therapeutic approach is reasonable, on the basis of the clinical parameters exhibited by hereditary persistence of fetal hemoglobin patients, (ii) clinical trials (even if still limited) employing HbF inducers were effective in ameliorating the symptoms of beta-thalassemia patients, (iii) good correlation of in vivo and in vitro results of HbF synthesis and gamma-globin mRNA accumulation indicates that in vitro testing might be predictive of in vivo responses and (iv) combined use of different inducers might be useful to maximize HbF, both in vitro and in vivo. In this review, we present three examples of HbF inducers from the natural world: (i) angelicin and linear psoralens, contained in plant extracts from Angelica arcangelica and Aegle marmelos, (ii) resveratrol, a polyphenol found in grapes and several plant extracts and (iii) rapamycin, isolated from Streptomyces hygroscopicus.