Cyclic Peptide Conjugate of Curcumin and Doxorubicin as an Anticancer Agent

The hydrophobicity of curcumin creates hurdle towards its use in the anticancer therapy. Herein, we synthesized a curcumin-doxorubicin conjugated cyclic peptide scaffold to improve the solubility of curcumin and create a conjugate containing two anticancer agents. A solid-phase Fmoc/tBu solid phase methodology was used to synthesize a cell-penetrating nuclear targeting peptide with free thiol and amine groups, which was coupled with the activated doxorubicin (Dox) and curcumin, affording Dox-peptide-curcumin conjugate (DPCC) (10). The antiproliferative activity of the conjugate was evaluated in human leukemia carcinoma cell (CCRF-CEM), human ovarian carcinoma cell (SKOV-3), and normal kidney cell line (LLCPK). Cyclic peptide-doxorubicin conjugate (7) and DPCC (10) did not inhibit the proliferation of normal kidney LLCPK cells after 72 h incubation, but were cytotoxic in CCRF-CEM (73% and 41%, respectively) and SKOV-3 (55% and 30%, respectively) cells under similar conditions, suggesting selectivity of these compounds towards cancer cells while Dox was cytotoxic (60- 79%) in all three cell lines under similar conditions

EDB-FN Targeted Peptide–Drug Conjugates for Use against Prostate Cancer

Prostate cancer (PCa) is the most common malignancy in men and is the leading cause of cancer-related male mortality. A disulfide cyclic peptide ligand [CTVRTSADC] 1 has been previously found to target extra domain B of fibronectin (EDB-FN) in the extracellular matrix that can dierentiate aggressive PCa from benign prostatic hyperplasia. We synthesized and optimized the stability of ligand 1 by amide cyclization to obtain [KTVRTSADE] 8 using Fmoc/tBu solid-phase chemistry. Optimized targeting ligand 8 was found to be stable in phosphate buered saline (PBS, pH 6.5, 7.0, and 7.5) and under redox conditions, with a half-life longer than 8 h. Confocal microscopy studies demonstrated increased binding of ligand 8 to EDB-FN compared to ligand 1. Therefore, we hypothesized that the EDB-FN targeted peptides (1 and 8) conjugated with an anticancer drug via a hydrolyzable linker would provide selective cytotoxicity to the cancer cells. To test our hypothesis, we selected both the normal prostate cell line, RWPE-1, and the cancerous prostate cell lines, PC3, DU-145, LNCaP, and C4-2, to evaluate the anticancer activity of synthesized peptide–drug conjugates. Docetaxel (Doce) and doxorubicin (Dox) were used as anticancer drugs. Dox conjugate 13 containing disulfide linkage showed comparable cytotoxicity versus Dox after 72 h incubation in all the cancer cell lines, whereas it was found to be less cytotoxic on RWPE-1, suggesting that it can act as a Dox prodrug. Doce conjugate 14 was found to be less cytotoxic in all the cell lines as compared to drug alone

Inducing Water Productivity from Snow Cover for Sustainable Water Management in Ibrahim River Basin, Lebanon

International audienceThe aim of this paper is to explore the effects and linkages between snow cover areas, distribution, probability and measured water discharge along east Mediterranean coastal watershed using moderate-resolution satellite images (MODIS-Terra). The Nahr Ibrahim River is a typical Lebanese watershed with an area of 326 km2 stretching between the sea and mountainous terrain to the east. The largest snow cover often exists in January-February with snow-free conditions between June and November. Image analysis enabled to analyze the temporal variability of the mean and maximum monthly areas of snow cover between 2000 and 2013. Snow cover dynamics were compared with the discharge from main springs (Afqa and Rouaiss) feeding the river and the probability of snow cover was estimated. The mean monthly snow cover, snow melting rates and springs discharge were found to be in direct relationship. In addition, the measured water discharge at the river mouth was found to be higher than the discharge of the two main feeding springs. This indicates a contribution of groundwater to the stream flow, which is again in direct connection with snow melting at the upper bordering slopes and probably from neighboring watersheds. Considering the characteristics of the mountainous rocks (i.e. Sinkholes, fissured and karstified limestone), the pedo-climatic and land cover conditions affect the hydrological regime which is directly responding to the area and temporal distribution of snow cover, which appears after two months from snowing events. This is reflected on water productivity and related disciplines (Agricultural yield, floods). This study highlights the potential of satellite snow detection over the watershed to estimate snow cover duration curve, forecast the stream flow regime and volume for better water management and flood risk preparedness

Synthesis and Antiproliferative Activities of Doxorubicin Thiol Conjugates and Doxorubicin-SS-cyclic Peptide

Myocardial toxicity and drug resistance caused by drug efflux are major limitations of doxorubicin (Dox)-based chemotherapy. Dox structure modification could be used to develop conjugates with an improved biological profile, such as antiproliferative activity and higher cellular retention. Thus, Dox thiol conjugates, Dox thiol (Dox-SH), thiol-reactive Dox-SS-pyridine (SS = disulfide), and a Dox-SS-cell-penetrating cyclic peptide, Dox-SS-[C(WR)4K], were synthesized. Dox was reacted with Traut\u27s reagent to generate Dox-SH. The thiol group was activated by the reaction with dithiodipyridine to afford the corresponding Dox-SS-Pyridine (Dox-SS-Pyr). A cyclic cell-penetrating peptide containing a cysteine residue [C(WR)4K] was prepared using Fmoc solid-phase strategy. Dox-SS-Py was reacted with the free sulfhydryl of cysteine in [C(WR)4K] to generate Dox-SS-[C(WR)4K] as a Dox-cyclic peptide conjugate. Cytotoxicity of the compounds was examined in human embryonic kidney (HEK-293), human ovarian cancer (SKOV-3), human fibrosarcoma (HT-1080), and human leukemia (CCRF-CEM) cells. Dox-SH and Dox-SS-pyridine were found to have significantly higher or comparable cytotoxicity when compared to Dox in HEK-293, HT-1080, and CCRF-CEM cells after 24 h and 72 incubation, presumably because of higher activity and retention of the compounds in these cells. Furthermore, Dox-SS-[C(WR)4K] showed significantly higher cytotoxic activity in HEK-293, HT-1080, and SKOV-3 cells when compared with Dox after 72 h incubation. Dox-SS-Pyr exhibited higher cellular uptake than Dox-SS-[C(WR)4K] in HT-1080 and HEK-293 cells as shown by flow cytometry. Fluorescence microscopy exhibited that Dox-SS-Pyr, Dox-SH, and Dox-SS-[C(WR)4K] localized in the nucleus as shown in four cell lines, HT-1080, SKOV-3, MDA-MB-468, and MCF-7. Of note, Dox-SS-[C(WR)4K] was significantly less toxic in mouse myoblast cells compared to Dox at the same concentration. Further mechanistic study demonstrated that the level of intracellular reactive oxygen species (ROS) in myoblast cells exposed to Dox-SS-[C(WR)4K] was reduced in comparison of Dox when co-treated with FeCl2. These data indicate that Dox-SH, Dox-SS-Pyr, and Dox-SS-[C(WR)4K] have the potential to be further examined as Dox alternatives and anticancer agents

Bis-Cinnamamide Derivatives as APE/Ref-1 Inhibitors for the Treatment of Human Melanoma

Human malignant melanoma exhibits imbalances in redox status, leading to activation of many redox-sensitive signaling pathways. APE/Ref-1 is a multifunctional protein that serves as a redox chaperone that regulates many nuclear transcription factors and is an important mechanism in cancer cell survival of oxidative stress. Previous studies showed that APE/Ref-1 is a potential druggable target for melanoma therapy. In this study, we synthesized a novel APE/Ref-1 inhibitor, bis-cinnamoyl-1,12-dodecamethylenediamine (2). In a xenograft mouse model, compound 2 treatment (5 mg/kg) significantly inhibited tumor growth compared to the control group, with no significant systemic toxicity observed. We further synthesized compound 2 analogs to determine the structure-activity relationship based on their anti-melanoma activities. Among those, 4-hydroxyphenyl derivative (11) exhibited potent anti-melanoma activities and improved water solubility compared to its parental compound 2. The IC50 of compound 11 was found to be less than 0.1 μM. Compared to other known APE/Ref-1 inhibitors, compound 11 exhibited increased potency in inhibiting melanoma proliferation. As determined by luciferase reporter analyses, compound 2 was shown to effectively inhibit H2O2-activated AP-1 transcription activities. Targeting APE/Ref-1-mediated signaling using pharmaceutical inhibitors is a novel and effective strategy for melanoma treatment with potentially high impact

A Small Peptide Increases Drug Delivery in Human Melanoma Cells

Melanoma is the most fatal type of skin cancer and is notoriously resistant to chemotherapies. The response of melanoma to current treatments is difficult to predict. To combat these challenges, in this study, we utilize a small peptide to increase drug delivery to melanoma cells. A peptide library array was designed and screened using a peptide array-whole cell binding assay, which identified KK-11 as a novel human melanoma-targeting peptide. The peptide and its D-amino acid substituted analogue (VPWxEPAYQrFL or D-aa KK-11) were synthesized via a solid-phase strategy. Further studies using FITC-labeled KK-11 demonstrated dose-dependent uptake in human melanoma cells. D-aa KK-11 significantly increased the stability of the peptide, with 45.3% remaining detectable after 24 h with human serum incubation. Co-treatment of KK-11 with doxorubicin was found to significantly enhance the cytotoxicity of doxorubicin compared to doxorubicin alone, or sequential KK-11 and doxorubicin treatment. In vivo and ex vivo imaging revealed that D-aa KK-11 distributed to xenografted A375 melanoma tumors as early as 5 min and persisted up to 24 h post tail vein injection. When co-administered, D-aa KK-11 significantly enhanced the anti-tumor activity of a novel nNOS inhibitor (MAC-3-190) in an A375 human melanoma xenograft mouse model compared to MAC-3-190 treatment alone. No apparent systemic toxicities were observed. Taken together, these results suggest that KK-11 may be a promising human melanoma-targeted delivery vector for anti-melanoma cargo

The integration of expert-defined importance factors to enrich Bayesian Fault Tree Analysis

International audienceThis paper proposes an analysis of a hybrid Bayesian-Importance model for system designers to improve the quality of services related to Active Assisted Living Systems. The proposed model is based on two factors: failure probability measure of different service components and, an expert defined degree of importance that each component holds for the success of the corresponding service. The proposed approach advocates the integration of expert-defined importance factors to enrich the Bayesian Fault Tree Analysis (FTA) approach. The evaluation of the proposed approach is conducted using the Fault Tree Analysis formalism where the undesired state of a system is analyzed using Boolean logic mechanisms to combine a series of lower-level events

In Silico Design, Synthesis, and In Vitro Evaluation of Novel Amphipathic Short Linear Peptides Against Clinically Relevant Bacterial Biofilms

Microbial biofilms are organized communities of cells that are associated with a wide spectrum of resistant and chronic infections that lead to the treatment failure. Accordingly, there is an urgent demand to create novel effective therapeutic drugs that can inhibit biofilm formation with new mechanisms of action to surmount the current escalating resistance. In this study, in silico hybrid model was utilized to develop three novel short linear peptides (4, 5, and 6) with potential biofilm inhibiting activities (scores \u3e 1.0). The peptides were composed of cationic and hydrophobic residues. They were synthesized using solid-phase strategy. Synthesized peptides were purified and characterized by reverse-phase high-performance liquid chromatography and matrix-assisted laser desorption/ionization spectroscopy, respectively. They were evaluated using in vitro assay as potential inhibitors of clinically relevant Gram-positive and Gram-negative biofilms. Peptide (4) with five positive charges at physiological pH (4 cationic moieties and W:R = 1:4) showed activity against biofilms of Gram-positive strains (Staphylococcus epidermidis and Listeria monocytogenes). On the other hand, peptide (5) with six positive charges (5 cationic moieties and W:R = 2:2) demonstrated activity against Gram-positive (S. epidermidis) and Gram-negative (Escherichia coli) biofilms. Interestingly, peptide (6), with seven positive charges (6 cationic moieties and W:R = 2:5) revealed higher and broader spectrum of activity against biofilms of Gram-positive (S. epidermidis, S. aureus, L. monocytogenes) and Gram-negative (E. coli)

Evaluation des caractéristiques physiques et des risques naturels dans le bassin versant du Nahr Ibrahim

International audienc

Evaluation des caractéristiques physiques et des risques naturels dans le bassin versant du Nahr Ibrahim

International audienc