5'-nucleotidase, cytosolic II genotype, and clinical outcome in patients with acute myeloid leukemia with intermediate-risk cytogenetics.

Acute myeloid leukemia (AML) is a complex disease, and its treatment needs to be adjusted to the risk, which is conferred by cytogenetics and molecular markers. Cytarabine is the main drug to treat AML, and it has been suggested that the genotype of cytarabine metabolizing enzymes may have a prognostic relevance in AML. Here we report the association between the 5'-nucleotidase, cytosolic II (NT5C2) rs10883841, cytidine deaminase (CDA) rs2072671 and rs532545 genotypes and the clinical outcome of 477 intermediate-risk cytogenetic AML patients receiving cytarabine-based chemotherapy. Patients younger than 50 years old with the NT5C2 rs10883841 AA genotype had lower overall survival (OS) (p: .003; HR 2.16, 95% CI 1.29-3.61) and lower disease-free survival (DFS) (p: .002; HR 2.45, 95% CI 1.41-4.27), associated to a higher relapse incidence (p: .010; HR 2.23, 95% CI 1.21-4.12). Interestingly, subgroup analysis showed that the negative effect of the NT5C2 rs10883841 AA genotype was detected in all subgroups except in patients with nucleophosmin mutation without high ratio FLT-3 internal tandem duplication. CDA polymorphisms were associated with the complete remission rate after induction chemotherapy, without influencing OS. Further studies are warranted to determine whether this pharmacogenomic approach may be helpful to individualize AML treatment.

Design, Preparation, and Characterization of Zn and Cu Metallopeptides Based On Tetradentate Aminopyridine Ligands Showing Enhanced DNA Cleavage Activity.

The conjugation of redox-active complexes that can function as chemical nucleases to cationic tetrapeptides is pursued in this work in order to explore the expected synergistic effect between these two elements in DNA oxidative cleavage. Coordination complexes of biologically relevant first row metal ions, such as Zn(II) or Cu(II), containing the tetradentate ligands 1,4-dimethyl-7-(2-pyridylmethyl)-1,4,7-triazacyclononane ((Me2)PyTACN) and (2S,2S')-1,1'-bis(pyrid-2-ylmethyl)-2,2'-bipyrrolidine ((S,S')-BPBP) have been linked to a cationic LKKL tetrapeptide sequence. Solid-phase synthesis of the peptide-tetradentate ligand conjugates has been developed, and the preparation and characterization of the corresponding metallotetrapeptides is described. The DNA cleavage activity of Cu and Zn metallopeptides has been evaluated and compared to their metal binding conjugates as well as to the parent complexes and ligands. Very interestingly, the oxidative Cu metallopeptides 1Cu and 2Cu show an enhanced activity compared to the parent complexes, [Cu(PyTACN)](2+) and [Cu(BPBP)](2+), respectively. Under optimized conditions, 1Cu displays an apparent pseudo first-order rate constant (kobs) of ∼0.16 min(-1) with a supercoiled DNA half-life time (t1/2) of ∼4.3 min. On the other hand, kobs for 2Cu has been found to be ∼0.11 min(-1) with t1/2 ≈ 6.4 min. Hence, these results point out that the DNA cleavage activities promoted by the metallopeptides 1Cu and 2Cu render ∼4-fold and ∼23 rate accelerations in comparison with their parent Cu complexes. Additional binding assays and mechanistic studies demonstrate that the enhanced cleavage activities are explained by the presence of the cationic LKKL tetrapeptide sequence, which induces an improved binding affinity to the DNA, thus bringing the metal ion, which is responsible for cleavage, in close proximity.

Enzyme-triggered delivery of chlorambucil from conjugates based on the cell-penetrating peptide BP16.

The undecapeptide KKLFKKILKKL-NH2 (BP16) is a non-toxic cell-penetrating peptide (CPP) that is mainly internalized into cancer cells through a clathrin dependent endocytic mechanism and localizes in late endosomes. Moreover, this CPP is able to enhance the cellular uptake of chlorambucil (CLB) improving its cytotoxicity. In this work, we further explored the cell-penetrating properties of BP16 and those of its arginine analogue BP308. We investigated the influence on the cytotoxicity and on the cellular uptake of conjugating CLB at the N- or the C-terminal end of these undecapeptides. The effect of incorporating the cathepsin B-cleavable sequence Gly-Phe-Leu-Gly in CLB-BP16 and CLB-BP308 conjugates was also evaluated. The activity of CLB was significantly improved when conjugated at the N- or the C-terminus of BP16, or at the N-terminus of BP308. While CLB alone was not active (IC50 of 73.7 to >100 µM), the resulting conjugates displayed cytotoxic activity against CAPAN-1, MCF-7, PC-3, 1BR3G and SKMEL-28 cell lines with IC50 values ranging from 8.7 to 25.5 µM. These results were consistent with the internalization properties observed for the corresponding 5(6)-carboxyfluorescein-labeled conjugates. The presence of the tetrapeptide Gly-Phe-Leu-Gly at either the N- or the C-terminus of CLB-BP16 conjugates further increased the efficacy of CLB (IC50 of 3.6 to 16.2 µM), which could be attributed to its selective release in the lysosomal compartment. Enzymatic assays with cathepsin B showed the release of CLB-Gly-OH from these sequences within a short time. Therefore, the combination of BP16 with an enzymatic cleavable sequence can be used as a drug delivery system for the effective uptake and release of drugs in cancer cells.

Identification of BP16 as a non-toxic cell-penetrating peptide with highly efficient drug delivery properties.

Antimicrobial peptides are an interesting source of non-cytotoxic drug delivery vectors. Herein, we report on the identification of a new cell-penetrating peptide (KKLFKKILKKL-NH2, BP16) from a set of antimicrobial peptides selected from a library of cecropin-melittin hybrids (CECMEL11) previously designed to be used in plant protection. This set of peptides was screened for their cytotoxicity against breast adenocarcinoma MCF-7, pancreas adenocarcinoma CAPAN-1 and mouse embryonic fibroblast 3T3 cell lines. BP16 resulted to be non-toxic against both malignant and non-malignant cells at concentrations up to 200 µM. We demonstrated by flow cytometry and confocal microscopy that BP16 is mainly internalized in the cells through a clathrin dependent endocytosis and that it efficiently accumulates in the cell cytoplasm. We confirmed that the cell-penetrating properties of BP16 are retained after conjugating it to the breast tumor homing peptide CREKA. Furthermore, we assessed the potential of BP16 as a drug delivery vector by conjugating the anticancer drug chlorambucil to BP16 and to a CREKA-BP16 conjugate. The efficacy of the drug increased between 6 and 9 times when conjugated to BP16 and between 2 and 4.5 times when attached to the CREKA-BP16 derivative. The low toxicity and the excellent cell-penetrating properties clearly suggest that BP16 is a suitable vector for the delivery of therapeutic agents into cells.

CD200 genotype is associated with clinical outcome of patients with multiple myeloma.

Immune dysfunction in patients with MM affects both the innate and adaptive immune system. Molecules involved in the immune response pathways are essential to determine the ability of cancer cells to escape from the immune system surveillance. However, few data are available concerning the role of immune checkpoint molecules in predicting the myeloma control and immunological scape as mechanism of disease progression. We retrospectively analyzed the clinical impact of the CD200 genotype (rs1131199 and rs2272022) in 291 patients with newly diagnosed MM. Patients with a CD200 rs1131199 GG genotype showed a median overall survival (OS) significantly lower than those with CC+CG genotype (67.8 months versus 94.4 months respectively; p: 0.022) maintaining significance in the multivariate analysis. This effect was specially detected in patients not receiving an autologous stem cell transplant (auto-SCT) (p < 0.001). In these patients the rs1131199 GG genotype negatively influenced in the mortality not related with the progression of MM (p: 0.02) mainly due to infections events.

Genetic variants of CTLA4 are associated with clinical outcome of patients with multiple myeloma.

Immune dysfunction in patients with multiple myeloma (MM) affects both the innate and adaptive immune system. Molecules involved in the immune checkpoint pathways are essential to determine the ability of cancer cells to escape from the immune system surveillance. However, few data are available concerning the role of these molecules in predicting the kinetics of progression of MM. We retrospectively analysed polymorphisms of CTLA4 (rs231775 and rs733618), BTLA (rs9288953), CD28 (rs3116496), PD-1 (rs36084323 and rs11568821) and LAG-3 (rs870849) genes in 239 patients with newly diagnosed MM. Patients with a CTLA4 rs231775 AA/AG genotype showed a median progression-free survival (PFS) significantly lower than those with GG genotype (32.3 months versus 96.8 months respectively; p: 0.008). The 5-year PFS rate was 25% for patients with grouped AA and AG genotype vs 55.4% for patients with GG genotype. Multivariate analysis confirmed the CTLA4 rs231775 genotype as an independent risk factor for PFS (Hazard Ratio (HR): 2.05; 95% CI: 1.0-6.2; p: 0.047). Our results suggest that the CTLA4 genotype may identify patients with earlier progression of MM. This polymorphism could potentially be used as a prognostic biomarker.

LAG3 genotype of the donor and clinical outcome after allogeneic transplantation from HLA-identical sibling donors.

Introduction: The association of polymorphisms in molecules involved in the immune response (checkpoint inhibitors) with the clinical outcome after allogeneic transplantation (alloHSCT) has been described. Lymphocyte Activation 3 (LAG3) is a surface protein that plays a regulatory role in immunity as an inhibitory immune checkpoint molecule. Methods: To determine its role in the alloHSCT setting, we analyzed 797 patients transplanted from HLA-identical sibling donors. The LAG3 rs870849 C>T polymorphism was genotyped in donors. Results: We detected a higher incidence of severe acute GVHD in patients transplanted from donors with TT genotype (p: 0.047, HR 1.64; 95% CI 1.01 - 2.67). Overall survival (OS) was worse for patients transplanted from donors with the rs870849 CT/TT genotype (0.020; HR, 1.44; 95% CI 1.06 - 1.96), as well as disease-free survival (DFS) (p: 0.002; HR 1.58, 95%CI: 1.18 - 2.14) and transplant-related mortality (TRM) (p< 0.001; HR: 1.88, 95% CI 1.29 - 2.74). When combining the LAG3 rs870849 and the PDCD1 rs36084323 genotypes of the donor, three genetic groups were well defined, allowing a good stratification of the risk of acute GVHD, TRM, OS and DFS. Discussion: We conclude that the LAG3 genotype of the donor may be considered in donors' selection. As this selection may be limited in the HLA-identical sibling donor scenario, further studies exploring the impact of LAG3 genotype of the donor in unrelated transplantation are warranted.

Pro-Oxidant Activity of Amine-Pyridine-Based Iron Complexes Efficiently Kills Cancer and Cancer Stem-Like Cells.

Differential redox homeostasis in normal and malignant cells suggests that pro-oxidant-induced upregulation of cellular reactive oxygen species (ROS) should selectively target cancer cells without compromising the viability of untransformed cells. Consequently, a pro-oxidant deviation well-tolerated by nonmalignant cells might rapidly reach a cell-death threshold in malignant cells already at a high setpoint of constitutive oxidative stress. To test this hypothesis, we took advantage of a selected number of amine-pyridine-based Fe(II) complexes that operate as efficient and robust oxidation catalysts of organic substrates upon reaction with peroxides. Five of these Fe(II)-complexes and the corresponding aminopyridine ligands were selected to evaluate their anticancer properties. We found that the iron complexes failed to display any relevant activity, while the corresponding ligands exhibited significant antiproliferative activity. Among the ligands, none of which were hemolytic, compounds 1, 2 and 5 were cytotoxic in the low micromolar range against a panel of molecularly diverse human cancer cell lines. Importantly, the cytotoxic activity profile of some compounds remained unaltered in epithelial-to-mesenchymal (EMT)-induced stable populations of cancer stem-like cells, which acquired resistance to the well-known ROS inducer doxorubicin. Compounds 1, 2 and 5 inhibited the clonogenicity of cancer cells and induced apoptotic cell death accompanied by caspase 3/7 activation. Flow cytometry analyses indicated that ligands were strong inducers of oxidative stress, leading to a 7-fold increase in intracellular ROS levels. ROS induction was associated with their ability to bind intracellular iron and generate active coordination complexes inside of cells. In contrast, extracellular complexation of iron inhibited the activity of the ligands. Iron complexes showed a high proficiency to cleave DNA through oxidative-dependent mechanisms, suggesting a likely mechanism of cytotoxicity. In summary, we report that, upon chelation of intracellular iron, the pro-oxidant activity of amine-pyrimidine-based iron complexes efficiently kills cancer and cancer stem-like cells, thus providing functional evidence for an efficient family of redox-directed anti-cancer metallodrugs.

Preparation of new half sandwich ruthenium arene complexes with aminophosphines as potential chemotherapeutics.

Aminophosphines 2-(diphenylphosphino)-1-methylimidazole (dpim) and diphenyl-2-pyridylphosphine (PPh(2)py) have been used to prepare two series of Ru(II) arene complexes of formulae [(η(6)-p-cymene)Ru(κ(2)-O,O'-X)(κ(1)-P-dpim)]Y (series a: 1a·Y-3a·Y) and [(η(6)-p-cymene)Ru(κ(2)-O,O'-X)(κ(1)-P-PPh(2)py)]Y (series b: 1b·Y-3b·Y) (where X=acac, acetylacetonate; bzac, benzoyl acetonate; dbzm, dibenzoyl methanoate; Y=BF(4), BPh(4)). The structures of 1a·BF(4), 1a·BPh(4), 3a·BF(4), 1b·BPh(4) and 3b·BPh(4) were determined by X-ray diffraction. The tetrafluoroborate derivatives are more soluble in organic solvents than their tetraphenylborate counterparts. Five BF(4)(-) derivatives (all except the unstable 1b·BF(4)) were selected to evaluate the cytotoxic behavior in vitro against the human cancer cell lines MCF-7 (breast cancer) and CAPAN-1 (pancreatic cancer). 2b·BF(4) and 3b·BF(4) exhibited IC(50) values similar to those of cisplatin. Electrophoresis and AFM studies showed good correspondence between the biological activity levels of 2b·BF(4) and 3b·BF(4) and their ability to modify the DNA structure. Hydrolytic studies indicate that aquation could be involved in the activation mechanism of these complexes and confirm that the hydrolysis rate of 3b·BF(4) is higher than that of 3a·BF(4). Thus, the cytotoxic activity trends are explained in terms of the higher reactivity of derivatives from series b, which in turn is rationalized as being the result of the electronic features of dpim and PPh(2)py established by cyclic voltammetry measurements.