Naringin inhibits the invasion and migration of human glioblastoma cell via downregulation of MMP-2 and MMP-9 expression and inactivation of p38 signaling pathway.

International audienceGliomas are the most common and malignant primary brain tumors. They are associated with a poor prognosis despite the availability of multiple therapeutic options. Naringin, a common dietary flavonoid abundantly present in fruits and vegetables, is believed to possess strong anti-proliferative and anti-cancer properties. However, there are no reports describing its effects on the invasion and migration of glioblastoma cell lines. Our results showed that the treatment of U251 glioma cell lines with different concentrations of naringin inhibited the invasion and migration of these cells. In addition, we revealed a decrease in the levels of matrix metalloproteinases (MMP-2) and (MMP-9) expression as well as proteinase activity in U251 glioma cells. In contrast, the expression of tissue inhibitor of metalloproteinases (TIMP-1) and (TIMP-2) was increased. Furthermore, naringin treatment decreased significantly the phosphorylated level of p38. Combined treatment with a p38 inhibitor (SB203580) resulted in the synergistic reduction of MMP-2 and MMP-9 expressions correlated with an increase of TIMP-1 and TIMP-2 expressions and the anti-invasive properties. However, p38 chemical activator (anisomycin) could block these effects produced by naringin, suggesting a direct downregulation of the p38 signaling pathway. These data suggest that naringin may have therapeutic potential for controlling invasiveness of malignant gliomas by inhibiting of p38 signal transduction pathways

PTEN-regulated AKT/FoxO3a/Bim signaling contributes to Human cell glioblastoma apoptosis by platinum-maurocalcin conjugate

International audienceA previous report has shown that a chimera between a platinum complexing agent (1) andthe cell penetrating peptide maurocalcin, synthesized with D-amino acids, (DMCa), termedPt-1-DMCa, is a highly successful anticancer compound that works by targeting theintracellular redox system in glioblastoma (GBM) cells. However, the detailed cellularmechanism whereby the conjugate specifically kills tumor cells remains unclear. Herein, weshow that Pt-1-DMCa induces apoptosis in Human U87 GBM cells through reactive oxygenspecies (ROS)-dependent modulation of the PI3K/AKT/FoxO3a signalling pathway. First, wefound that Pt-1-DMCa treatment of these cells induces inhibition of AKT and nuclearaccumulation of FoxO3a thereby facilitating transcription of the target genes Bim and PTEN.Modulation of the AKT/FoxO3a/Bim signaling pathway by RNA interference confirms thatthese signaling events are critical for Pt-1-DMCa-induced apoptosis of U87 GBM cells.Furthermore, we reveal that FoxO3a-mediated up-regulation of PTEN exerts an additionalinhibitory effect on the AKT survival pathway. Thus, our results demonstrate that theconjugate can induce ROS-dependent FoxO3a-mediated apoptosis in U87 cells throughPTEN-mediated inhibition of the PI3K/AKT survival axis. Our results help elucidate themolecular mechanisms underlying Pt-1-DMCa-induced cell death in U87 GBM cells andsupport a theoretical basis for future applications of the MCa peptid

A Conjugate between Lqh-8/6, a Natural Peptide Analogue of Chlorotoxin, and Doxorubicin Efficiently Induces Glioma Cell Death

International audienceNatural peptides isolated from animal venoms generally target cell surface receptors with high affinity and selectivity. On many occasions, some of these receptors are over-expressed in cancer cells. Herein, we identified Lqh-8/6 as a natural peptide analog of chlorotoxin, a proven and useful compound for the diagnosis and treatment of glioma. Lqh-8/6 and two other natural analogues were chemically synthesized for the first time and evaluated for their ability to label, detect and prevent glioma growth in vitro. We demonstrate that a biotinylated version of Lqh-8/6 allows both the labeling of glioma cell lines and the detection of glioma in brain sections of glioma allograft Fisher rats. Lqh-8/6 has intrinsic anti-invasive properties but is non-toxic to glioma cells. To confer anti-tumor properties to Lqh-8/6, we chemically coupled doxorubicin to the glioma-targeting peptide using click chemistry. To this end, we successfully chemically synthesized Lqh-8/6-azide and doxorubicin-alkyne without impairing the toxic nature of doxorubicin. The toxin-drug conjugate efficiently promotes the apoptosis of glioma cells in vitro. This example contributes to the concept that animal venom peptides constitute exquisite warheads for delivering toxic chemical conjugates, a parallel to the popular concept of antibody-drug conjugates for the treatment of cancer

Phthalimido-ferrocidiphenol cyclodextrin complexes: Characterization and anticancer activity

International audienceSeveral ferrocenyl analogues of tamoxifen have already showed strong antiproliferative activity in experimental glioma models. Nevertheless, these compounds are very poorly soluble in water and an adapted formulation is needed. In this work, we have tailored and optimized methylated cyclodextrin soluble complexes of phthalimido-ferrocidiphenol for the first time. The complexes were characterized, and the optimized formulation was tested for in vitro efficacy and cell proliferation assays on U87, human glioblastoma cancer cells. Molecular modeling can provide accurate information about the inclusion process. The inclusion of all the moieties at the same time (i.e., ferrocene, phthalimidylpropyl, 2 phenols) is not possible due to the steric hindrance of the 1:4 system. The 1:3 systems are possible but do not seem very relevant. However, various 1:2 and 1:1 complexes are mostly present in aqueous solutions. Some experiments have confirmed our hypothesis. First, interactions between the phenol, phthalimidylpropyl and ferrocenyl groups have been observed in our NMR experiments. Second, the inclusion of phthalimidylpropyl was detected by UV-vis spectrophotometry with an apparent 1:1 interaction, which was observed through the Benesi-Hildebrand method. The complex is readily soluble in water and keeps its pharmacological activity against U87 tumor cells (IC50=0.028 ± 0.007 μM vs. 0.018 ± 0.003 μM for PhtFerr)

Anticancer properties of lipid and poly(ε-caprolactone) nanocapsules loaded with ferrocenyl-tamoxifen derivatives

International audienceObjectiveWe synthesized new tamoxifen derivatives as anticancer drug candidates and elaborated on convection‐enhanced delivery (CED) as a strategy for delivery.MethodsTo overcome the issue of their poor solubility, these ferrocenyl‐tamoxifen derivatives were esterified and encapsulated into different nanocarriers, that is lipid (LNC) and polymeric nanocapsules (PNL‐NC). We describe the chemistry, the encapsulation and the physicochemical characterization of these formulations.Key findingsStarting compounds [phthalimido‐ferrocidiphenol and succinimido‐ferrocidiphenol], esterified prodrugs and their nanocapsules formulations were characterized.These drug candidates displayed a strong in vitro activity against breast and glioblastoma cancer cells. The ester prodrugs were toxic for glioblastoma cells (IC50 = 9.2 × 10−2 μm and 6.7 × 10−2 μm, respectively). The IC50 values for breast cancer cells were higher for these compounds. The encapsulation of the esterified compounds in LNCs (≈50 nm) or PCL‐NCs (≈300 nm) did not prevent their efficacy on glioblastoma cells. These anticancer effects were due to both blockade in the S‐phase of the cell cycle and apoptosis. Moreover, the tamoxifen derivatives‐loaded nanocapsules induced no toxicity for healthy astrocytes and showed no haemolytic properties. Loaded Lipid Nanocapsules (LNCs) presented interesting profiles for the optimal delivery of active compounds.ConclusionsPhthalimido‐ and Succinimido‐esters represent an innovative approach to treat cancers with cerebral localizations such as glioblastoma or brain metastases from breast cancers

Succinimido–Ferrocidiphenol Complexed with Cyclodextrins Inhibits Glioblastoma Tumor Growth In Vitro and In Vivo without Noticeable Adverse Toxicity

International audienceSuccFerr (N-[4-ferrocenyl,5-5-bis (4-hydroxyphenyl)-pent-4-enyl]-succinimide) has remarkable antiproliferative effects in vitro, attributed to the formation of a stabilized quinone methide. The present article reports in vivo results for a possible preclinical study. SuccFerr is lipophilic and insoluble in water, so the development of a formulation to obviate this inconvenience was necessary. This was achieved by complexation with randomly methylated cyclodextrins (RAMEßCDs). This supramolecular water-soluble system allowed the in vivo experiments below to proceed. Application of SuccFerr on the glioblastoma cancer cell line U87 indicates that it affects the cellular cycle by inducing a blockade at G0/G1 phase, linked to apoptosis, and another one at the S phase, associated with senescence. Using healthy Fischer rats, we show that both intravenous and subcutaneous SuccFerr: RAMEßCD administration at 5 mg/kg lacks toxic effects on several organs. To reach lethality, doses higher than 200 mg/kg need to be administered. These results prompted us to perform an ectopic in vivo study at 1 mg/kg i.v. ferrocidiphenol SuccFerr using F98 cells xenografted in rats. Halting of cancer progression was observed after six days of injection, associated with an immunological defense response linked to the active principle. These results demonstrate that the properties of the selected ferrocidiphenol SuccFerr transfer successfully to in vivo conditions, leading to interesting therapeutic perspectives based on this chemistry

A New Series of Succinimido-ferrociphenols and Related Heterocyclic Species Induce Strong Antiproliferative Effects, Especially against Ovarian Cancer Cells Resistant to Cisplatin

Ferrociphenols are known to display anticancer properties by original mechanisms dependent on redox properties and generation of active metabolites such as quinone methides. Recent studies have highlighted the positive impact of oxidative stress on chemosensitivity and prognosis of ovarian cancer patients. Ovarian adenocarcinomas are shown to be an excellent model for defining the impact of selected ferrociphenols as new therapeutic drugs for such cancers. This work describes the syntheses and preliminary mechanistic research of unprecedented multitargeting heterocyclic ferrociphenols bearing either a succinimidyl or phthalimidyl group that show exceptional antiproliferative behavior against epithelial ovarian cancer cells resistant to cisplatin. Owing to the failure of the present pharmaceutical options, such as carboplatin a metallodrug based on Pt coordination chemistry, these species may help to overcome the problem of lethal resistance. Currently, ferrociphenolic entities generally operate via apoptotic and senescence pathways. We present here our first results in this new cyclic-imide series