betadex and Prostatic-Neoplasms

Targeted drug delivery by nanocarriers molecules can increase the efficiency of cancer treatment. One of the targeting ligands is folic acid (FA), which has a high affinity for the folic acid receptors, which are overexpressed in many cancers. Herein, we describe the preparation of the nanoconjugates containing quantum dots (QDs) and

Topics: Acridines; Antineoplastic Agents; beta-Cyclodextrins; Cell Line, Tumor; Drug Carriers; Drug Delivery Systems; Folic Acid; Humans; Lung; Lung Neoplasms; Male; Nanoconjugates; Nanostructures; Prostate; Prostatic Neoplasms; Quantum Dots

Targeted delivery of drugs into specific cancer cells is an effective way to enhance the efficacy and minimize the side effects of therapy. Prostate malignant cells overexpress the prostate-specific membrane antigen (PSMA), a membrane protein that may be a valid target for selective drug administration. To target prostate cancer cells, a β-cyclodextrin perfunctionalised with dipeptide-like urea arms, a well-established mimic of a selective ligand against PSMA, is herein reported, to develop a multivalent drug delivery and targeting system. Firstly, fluorescein was used to validate the system on cells that express high levels of PSMA (prostate tumoral cells, LNCap) or very low levels of PSMA (non-tumoral cells, Hek293T). Then, the antineoplastic agent doxorubicin complexed with β-cyclodextrin functionalized with PSMA-like ligand takes less time to induce cytotoxicity on LNCap cells compared to doxorubicin alone. This might represent a promising drug-delivery approach to selectively target prostate cancer cells.

Topics: Antigens, Surface; beta-Cyclodextrins; Cell Line, Tumor; Doxorubicin; Glutamate Carboxypeptidase II; HEK293 Cells; Humans; Ligands; Male; Prostatic Neoplasms; Urea

The complexation of the bioactive compound oxyresveratrol (OXY) with a polymer called cyclodextrin-based nanosponge (CD-NS) and its application was studied.A new methodology is used to calculate, an apparent inclusion complex constant (K

Topics: Antineoplastic Agents; beta-Cyclodextrins; Colonic Neoplasms; HCT116 Cells; Humans; Male; Nanostructures; Plant Extracts; Polymers; Prostatic Neoplasms; Solubility; Stilbenes; Temperature

Prostate cancer is a leading cause of cancer-related death in men and RNA interference (RNAi) has emerged as a potential therapeutic option. However, the absence of a safe and specific delivery vector remains a major obstacle to the clinical application of RNAi. Cyclodextrin derivatives are known to be efficient delivery systems with low toxicity in a variety of cell types. In this study, a cationic cyclodextrin derivative was synthesized to complex siRNA. The nanoparticle was then further modified by exploiting the ability of the β-cyclodextrin cavity to form an inclusion complex with the hydrophobic molecule adamantane. PEGylated adamantane derivatives were synthesized with and without the anisamide-targeting ligand on the terminal end of the PEG chain. Anisamide is known to bind specifically to the sigma receptor which is overexpressed on the surface of prostate cancer cells. The resulting nanocomplexes were slightly cationic and less than 300 nm in size. They successfully protected siRNA from serum-induced nuclease degradation and were non-toxic to prostate cancer cells. In addition, the targeted nanoparticles mediated high levels of siRNA cellular uptake and corresponding PLK1 gene knockdown in prostate cancer cells in vitro. To our knowledge, this is the first time that the ability of cyclodextrins to form inclusion complexes with adamantane derivatives has been exploited for the targeted delivery of siRNA to prostate cancer cells via the sigma receptor.

Topics: Adamantane; beta-Cyclodextrins; Cations; Cell Cycle Proteins; Cell Line, Tumor; Gene Knockdown Techniques; Gene Transfer Techniques; Humans; Male; Nanoparticles; Particle Size; Polo-Like Kinase 1; Prostatic Neoplasms; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins; Receptors, sigma; RNA Interference; RNA, Small Interfering; Sigma-1 Receptor

In this work, silver nanoparticles-doped Pb (II) metal-organic framework (Ag-MOF) was prepared and exploited as a luminescence probe for the development of label-free electrochemiluminescence (ECL) immunosensing scheme for prostate-specific antigen (PSA). The β-cyclodextrin based MOF, Pb-β-cyclodextrin (Pb(II)-β-CD) shows excellent ECL behavior and unexpected reducing capacity towards silver ions. Silver nanoparticles could massively form on the surface of Pb(II)-β-CD (Ag@Pb(II)-β-CD) without use any additional reducing agent, while the ECL behavior of Pb(II)-β-CD still was well retained. The Ag@Pb(II)-β-CD was used as a substrate material to modify glass carbon electrodes and formed a sensing platform for the fabricating ECL immunosensor. The presence of silver nanoparticles enables the facile immobilization of capturing antibody of PSA. The specific binding of PSA onto the electrode surface induces the decrease of ECL signals. A linear range of 0.001-50 ng mL(-1) with a detection limit of 0.34 pg mL(-1) (S/N=3) was obtained after the optimization of experimental conditions. This simply fabricated immunosensor exhibits good stability, accuracy and acceptable reproducibility, which suggesting its potential applications in clinical diagnostics.

Topics: beta-Cyclodextrins; Biosensing Techniques; Electrochemical Techniques; Humans; Lead; Limit of Detection; Male; Metal Nanoparticles; Prostate-Specific Antigen; Prostatic Neoplasms; Silver

Camptothecin (CPT), a pentacyclic alkaloid, is an inhibitor of DNA Topoisomerase-I and shows a wide spectrum of anti-cancer activities. The use of CPT has been hampered by poor aqueous solubility and a high degradation rate. Previously, it has been reported that CPT encapsulated in β-cyclodextrin-nanosponges (CN-CPT) overcomes these disadvantages and improves the CPT's inhibitory effect on DU145 prostate tumor cell lines, and PC-3 growth in vitro. This work extends these observations by showing that CN-CPT significantly inhibits the adhesion and migration of these tumor cells and their STAT3 phosphorylation. The anti-adhesive effect is exerted also in human endothelial cells, in which CN-CPT also inhibits the angiogenic activity as assessed by the tubulogenesis and sprouting assays. Finally, CN-CPT substantially delays the growth of PC-3 cell engraftment in SCID mice in vivo without apparent toxic effects. These results support the use of β-cyclodextrin nanosponge nanotechnology as a potential nanocarrier for delivery of anticancer drugs in the treatment of prostate cancers.

Topics: Absorption, Physicochemical; Animals; Antineoplastic Agents, Phytogenic; Apoptosis; beta-Cyclodextrins; Camptothecin; Cell Line, Tumor; Cell Survival; Diffusion; Humans; Male; Mice; Mice, SCID; Nanocapsules; Porosity; Prostatic Neoplasms

Paclitaxel (PTX), a hydrophobic anticancer drug, is facing several clinical limitations such as low bioavailability and drug resistance. To solve the problems, a well-defined β-cyclodextrin-poly(N-isopropylacrylamide) star polymer was synthesized and used as a nanocarrier to improve the water solubility and aim to thermoresponsive delivery of PTX to cancer cells. The star polymer was able to form supramolecular self-assembled inclusion complex with PTX via host-guest interaction at room temperature, which is below the low critical solution temperature (LCST) of the star polymer, significantly improving the solubilization of PTX. At body temperature (above LCST), the phase transition of poly(N-isopropylacrylamide) segments induced the formation of nanoparticles, which greatly enhanced the cellular uptake of the polymer-drug complex, resulting in efficient thermoresponsive delivery of PTX. In particular, the polymer-drug complex exhibited better antitumor effects than the commercial formulation of PTX in overcoming the multi-drug resistance in AT3B-1 cells.

Topics: Acrylamides; Animals; Antineoplastic Agents, Phytogenic; beta-Cyclodextrins; Cell Survival; Drug Delivery Systems; Drug Resistance, Multiple; Drug Resistance, Neoplasm; Inclusion Bodies; Male; Nanoparticles; Paclitaxel; Polymers; Prostatic Neoplasms; Rats; Temperature; Tumor Cells, Cultured

Telmisartan (TEL) requires superior bioavailability in cancer cell compartments. To meet these challenges, we have synthesized a 2-HP-β-CD-TEL complex with stability constant (Kc) of 2.39 × 10(-3)mM. The absence in the FTIR spectrum of 2-HP-β-CD-TEL complex of the characteristic peaks of TEL at 1,699 cm(-1) (carboxylic acid) and 741 and 756 cm(-1) (1,2-disubstituted benzene ring vibrations), is indicative of the encapsulation of TEL in the 2-HP-β-CD cavity. DSC and PXRD also confirmed the synthesis and amorphous structure of complex. The interaction of TEL with 2-HP-β-CD was examined by NMR and 2D-ROESY which affirms the encapsulation of TEL in the 2-HP-β-CD cavity in at least two orientations with equal binding energies. The complex also exhibited its superiority in both in vitro release and cytotoxicity experiments on prostate cancer, PC-3 cells as compared to free drug. These data warrant an in depth in vivo to scale-up the technology for the management of prostate cancer.

Topics: 2-Hydroxypropyl-beta-cyclodextrin; Benzimidazoles; Benzoates; beta-Cyclodextrins; Cell Line, Tumor; Computer Simulation; Drug Carriers; Humans; Male; Models, Molecular; Molecular Conformation; Prostatic Neoplasms; Solubility; Telmisartan

Prostate cancer (PC) is the most frequently diagnosed disease in men in the United States. Curcumin (CUR), a natural diphenol, has shown potent anti-cancer efficacy in various types of cancers. However, suboptimal pharmacokinetics and poor bioavailability limit its effective use in cancer therapeutics. Several successful CUR nanoformulations have recently been reported which improve upon these features; however, there is no personalized safe nanoformulation for prostate cancer. This study contributes two important scientific aspects of prostate cancer therapeutics. The first objective was to investigate the comparative cellular uptake and cytotoxicity evaluation of β-cyclodextrin (CD), hydroxypropyl methylcellulose (cellulose), poly(lactic-co-glycolic acid) (PLGA), magnetic nanoparticles (MNP), and dendrimer based CUR nanoformulations in prostate cancer cells. Curcumin loaded cellulose nanoparticles (cellulose-CUR) formulation exhibited the highest cellular uptake and caused maximum ultrastructural changes related to apoptosis (presence of vacuoles) in prostate cancer cells. Secondly, the anti-cancer potential of the cellulose-CUR formulation was evaluated in cell culture models using cell proliferation, colony formation and apoptosis (7-AAD staining) assays. In these assays, the cellulose-CUR formulation showed improved anti-cancer efficacy compared to free curcumin. Our study shows, for the first time, the feasibility of cellulose-CUR formulation and its potential use in prostate cancer therapy.

Topics: Apoptosis; beta-Cyclodextrins; Cell Line, Tumor; Cell Proliferation; Cellulose; Chemistry, Pharmaceutical; Curcumin; Humans; Lactic Acid; Magnetics; Male; Nanoparticles; Polyglycolic Acid; Polylactic Acid-Polyglycolic Acid Copolymer; Prostatic Neoplasms; Tumor Stem Cell Assay

To investigate the molecular interaction between β-cyclodextrin (βCD) or hydroxypropyl-β-cyclodextrin (HPβCD) and riboflavin (RF), and to test the anticancer potential of these formulations.. The physicochemical characterization of the association between RF and CDs was performed by UV-vis absorption, fluorescence, differential scanning calorimetry and NMR techniques. Molecular dynamics simulation was used to shed light on the mechanism of interaction of RF and CDs. Additionally, in-vitro cell culture tests were performed to evaluate the cytotoxicity of the RF-CD complexes against prostate cancer cells.. Neither βCD nor HPβCD led to substantial changes in the physicochemical properties of RF (with the exception of solubility). Additionally, rotating frame Overhauser effect spectroscopy experiments detected no spatial correlations between hydrogens from the internal cavity of CDs and RF, while molecular dynamics simulations revealed 'out-of-ring' RF-CD interactions. Notwithstanding, both RF-βCD and RF-HPβCD complexes were cytotoxic to PC3 prostate cancer cells.. The interaction between RF and either βCD or HPβCD, at low concentrations, seems to be made through hydrogen bonding between the flavonoid and the external rim of both CDs. Regardless of the mechanism of complexation, our findings indicate that RF-CD complexes significantly increase RF solubility and potentiate its antitumour effect.

Topics: 2-Hydroxypropyl-beta-cyclodextrin; Antineoplastic Agents; beta-Cyclodextrins; Cell Line, Tumor; Drug Carriers; Humans; Hydrogen Bonding; Male; Prostatic Neoplasms; Riboflavin; Solubility

A hepta-guanidino-β-cyclodextrin (G-CD), its hepta-PEG conjugate (G-CD-PEG), and the corresponding anisamide-terminated PEG conjugate (G-CD-PEG-AA) have been synthesised and compared as delivery vectors for siRNA to prostate cancer cells and tumours in vivo. The G-CD-PEG-AA.siRNA formulations (in which anisamide targets the sigma receptor), but not the non-targeted formulations, induced prostate cell-specific internalisation of siRNA resulting in approximately 80% knockdown in vitro of the reporter gene, luciferase. Following intravenous administration of the anisamide-targeted formulation in a mouse prostate tumour model significant tumour inactivation with corresponding reductions in the level of vascular endothelial growth factor (VEGF) mRNA were achieved, without demonstrating enhanced toxicity. This data imply significant potential for anisamide-conjugated cyclodextrin vectors for targeted delivery of therapeutic siRNAs in the treatment of prostate cancer.

Topics: Administration, Intravenous; Animals; Antineoplastic Agents; Benzamides; beta-Cyclodextrins; Cell Death; Cell Line, Tumor; Endocytosis; Fluorescein; Gene Silencing; Gene Transfer Techniques; Genes, Reporter; Humans; Intracellular Space; Male; Mice; Mice, Inbred C57BL; Nanoparticles; Prostatic Neoplasms; RNA, Small Interfering; Vascular Endothelial Growth Factor A

Camptothecin (CPT) is a potent DNA Topoisomerase I inhibitor with anti-tumor activity in hematological and solid tumors. However, it did not reach clinical use because of its poor solubility and high degrability. β-Cyclodextrin nanosponge (CN) have been demonstrated to be able to increase the solubility of lipophilic compounds and to protect them from degradation. In the present study, we evaluated whether β-Cyclodextrin nanosponge carriers can overcome CPT chemical disadvantages and improve the in vitro anti-tumor efficacy in the androgen refractory models of prostate cancer DU145 and PC-3 and the androgen sensitive model LNCaP. Camptothecin-loaded β-Cyclodextrin nanosponge (CN-CPT) showed sizes of about 400 nm, spherical shape and a drug loading of 38%. HPLC analysis, performed on the cell pellet after treatment with CN-CPT revealed that CPT concentration increased over time indicating a prolonged release of the drug. Moreover, CN-CPT inhibited Topoisomerase I activity, and induced DNA damage, and cell cycle arrest more effectively than CPT, indicating that the CN-CPT formulation does not affect activity of the drug. Moreover, Annexin V/Propidium Iodide staining showed an induction of cell death at low concentrations that were not effective for CTP. LNCaP cells were less sensitive to CPT than PC-3 and DU145 cells, but CN-CPT still exerted higher anti-proliferative activity and DNA damage ability than CPT. The experiments performed in LNCaP cells demonstrated that CN-CPT treatment inhibited expression of the androgen receptor at doses where CPT was ineffective. Our results demonstrated the higher anti-tumor effectiveness of CN-CPT compare to CPT in prostate cancer cells, supporting the relevance of future studies for the use of the β-Cyclodextrin nanosponge to deliver anticancer drugs in vivo.

Topics: Androgens; Antineoplastic Agents; beta-Cyclodextrins; Camptothecin; Cell Cycle Checkpoints; Cell Death; Cell Line, Tumor; Cell Proliferation; Chemistry, Pharmaceutical; DNA Damage; Drug Carriers; Histones; Humans; Male; Nanostructures; Particle Size; Phosphorylation; Prostatic Neoplasms; Solubility; Topoisomerase I Inhibitors

The purpose of this study is to develop novel stable PEGylated liposome vincristine formulations with optimal antitumor efficacy. Vincristine could interact with negatively charged distearoylphosphatidylethanolamine-polyethylene glycol (DSPE-PEG), leading to rapid drug release from vesicles. To improve drug retention, vincristine was loaded into vesicles using sulfobutyl ether cyclodextrin (sbe-CD) as trapping agent. Despite that, vincristine could not form a precipitate with sbe-CD; the aggregation status of vincristine/sbe-CD inside vesicles must be complicated because drug retention was considerably improved in vivo. Theoretical consideration revealed that the release constant K equals to pA(m)k(1)k(2)/([H(+)](i)[sbe(-)](i)V(i) ), which can be used to expound why increasing drug/lipid ratio induced decreased vincristine circulation half-life. The stabilization effect afforded by sbe-CD was sufficient to surpass DSPE-PEG-induced drug leakage, so PEGylated liposomal vincristine formulations with prolonged circulation half-life (t(1/2): from 43.6 to 70.0 h) could be achieved, of which the formulation pLV-c-2.9-3 exhibited optimal antitumor effects and reduced toxicity. The strategy might be used to load other vinca alkaloids into PEGylated liposomes and improve their retention inside vesicles.

Topics: Analysis of Variance; Animals; Antineoplastic Agents, Phytogenic; beta-Cyclodextrins; Cell Line, Tumor; Chemistry, Pharmaceutical; Delayed-Action Preparations; Drug Carriers; Drug Compounding; Drug Stability; Female; Injections, Intravenous; Kinetics; Liposomes; Male; Maximum Tolerated Dose; Mice; Mice, Inbred C57BL; Mice, Inbred DBA; Models, Chemical; Phosphatidylethanolamines; Polyethylene Glycols; Prostatic Neoplasms; Solubility; Technology, Pharmaceutical; Tumor Burden; Vincristine

Liposomal delivery of irinotecan could provide protection against drug hydrolysis, deliver more active lactone form to tumours and prolong irinotecan exposure time. Nevertheless, conventional drug-loading technologies have typically resulted in undesired drug retention properties. To resolve the problem, a modified gradient loading method was developed and the resulting formulations were evaluated in a systemic manner.. Irinotecan was loaded into liposomes using a novel sulfobutyl ether beta-cyclodextrin (sbe-CD) gradient. The effect of drug-to-lipid ratio (D/L) and polyethylene glycol (PEG) grafting density were investigated. Drug release experiments were performed in ammonium-containing medium based on the fluorescence dequenching phenomenon of irinotecan. Pharmacokinetic studies were performed in normal balb/c mice treated with different formulations. To compare the anti-tumour effect of different formulations, an RM-1 prostate cancer model was used. Acute toxicity studies were performed in healthy female c57 mice.. Irinotecan could be encapsulated into liposomes with >90% loading efficiency at a high drug-to-lipid mass ratio (>0.5). In-vitro release experiments revealed that sbe-CD anion was more able to retain irinotecan than sulfate. Moreover, the elevated D/L ratio elicited decreased drug release kinetics. Both trends had also been observed when the effects of anions and D/L ratio on half-life of irinotecan were assessed. Pegylated liposomal irinotecan loaded with sbe-CD/triethylammonium gradient had irinotecan half-life values ranging from 9.4 to 13.1 h, surpassing vesicles prepared by the triethylammonium sulfate method (∼4.5 h). In the RM-1 tumour model, all the liposomal irinotecan formulations were more therapeutically active than free irinotecan and the formulation with a high D/L ratio was the most efficacious. Moreover, the high D/L formulation might be less toxic than free irinotecan based on acute toxicity studies.. The novel sbe-CD gradient could mediate effective irinotecan loading and improve irinotecan retention, thus resulting in highly active liposomal irinotecan formulations. The improvement in drug retention might be associated with the formation of complicated aggregates inside vesicles.

Topics: Ammonium Sulfate; Animals; Antineoplastic Agents; beta-Cyclodextrins; Camptothecin; Capsules; Female; Half-Life; Irinotecan; Lipids; Liposomes; Male; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Polyethylene Glycols; Prostatic Neoplasms; Technology, Pharmaceutical

Soy isoflavones and cholesterol have been reported as dietary factors related to the incidence of prostate cancer. In this study, we investigated whether cell survival could be suppressed by a combination of the dispersion of lipid raft microdomains and treatment with genistein, a well-known potential isoflavone, in LNCaP prostate cancer cells. Cell viability was assayed by the property of reagent change upon reduction of resazurin to resorufin and apoptosis was evaluated by ethidium bromide/acridine orange (EB/AO) staining and PARP and caspase-3 expression. Signal transduction was investigated by immunoblot analysis. Cell viability decreased significantly more following successive double treatment with genistein and the cholesterol-lowering agent 2-hydroxypropyl-beta-cyclodextrin (HPCD) than in response to either agent alone. Apoptotic cell staining and cleavage of PARP and caspase-3 appeared more clearly in double-treated cells than in those treated with genistein alone. In cell signaling, both HPCD and genistein decreased the protein expressions of pAkt as well as the androgen receptors stimulated by EGF and DHT, respectively, in concentration-dependent manners. This pattern was also present in protein levels of pAkt and the androgen receptor located in the lipid raft fraction. Furthermore, the phosphorylation cascade of Akt, GSK-3beta and p70S6k was markedly inhibited by the combination treatment. These data suggest that prostate cancer cells could be effectively inhibited by combination treatment of cholesterol-lowering strategies and genistein. The mechanism is likely to be partially via both the EGFR-mediated Akt or p70S6k pathways and a down-regulation of androgen receptor in the lipid raft microdomain.

Topics: 2-Hydroxypropyl-beta-cyclodextrin; Androgen Receptor Antagonists; Anticholesteremic Agents; beta-Cyclodextrins; Cell Survival; Cholesterol; Down-Regulation; ErbB Receptors; Genistein; Humans; Male; Membrane Microdomains; Prostatic Neoplasms; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-akt; Ribosomal Protein S6 Kinases, 70-kDa

Curcumin, a hydrophobic polyphenolic compound derived from the rhizome of the herb Curcuma longa, possesses a wide range of biological applications including cancer therapy. However, its prominent application in cancer treatment is limited due to sub-optimal pharmacokinetics and poor bioavailability at the tumor site. In order to improve its hydrophilic and drug delivery characteristics, we have developed a beta-cyclodextrin (CD) mediated curcumin drug delivery system via encapsulation technique. Curcumin encapsulation into the CD cavity was achieved by inclusion complex mechanism. Curcumin encapsulation efficiency was improved by increasing the ratio of curcumin to CD. The formations of CD-curcumin complexes were characterized by Fourier transform infrared (FTIR), differential scanning calorimetry (DSC), thermo-gravimetric analysis (TGA), scanning electron microscope (SEM), and transmission electron microscope (TEM) analyses. An optimized CD-curcumin complex (CD30) was evaluated for intracellular uptake and anti-cancer activity. Cell proliferation and clonogenic assays demonstrated that beta-cyclodextrin-curcumin self-assembly enhanced curcumin delivery and improved its therapeutic efficacy in prostate cancer cells compared to free curcumin.

Topics: Antineoplastic Agents; beta-Cyclodextrins; Calorimetry, Differential Scanning; Cell Line, Tumor; Cell Proliferation; Cell Survival; Curcumin; Drug Compounding; Drug Delivery Systems; Humans; Male; Microscopy, Electron; Prostatic Neoplasms; Spectroscopy, Fourier Transform Infrared; Thermogravimetry; Tumor Stem Cell Assay; X-Ray Diffraction

A novel PCD/CUR self-assembly approach for improved curcumin delivery to prostate cancer cells is described. The formation of PCD/CUR was confirmed using FTIR, DSC, TGA, and SEM/TEM, and their stability and solubility under physiological conditions was demonstrated. A mechanism for self-assembly is proposed. Intracellular uptake of the self-assemblies was studied by flow cytometry and immunofluorescence microscopy. The therapeutic efficacy was determined by cell proliferation and colony formation assays using C4-2, DU145 and PC3 prostate cancer cells. The results suggest that the PCD/CUR formulation could be a useful system for improving curcumin delivery and its therapeutic efficacy in prostate cancer.

Topics: Antineoplastic Agents; beta-Cyclodextrins; Cell Line, Tumor; Curcumin; Drug Delivery Systems; Humans; Male; Models, Molecular; Propylene Glycols; Prostatic Neoplasms

The HGF/c-Met pathway is an important regulator of signaling pathways responsible for invasion and metastasis of most human cancers, including prostate cancer. Exposure of DU145 prostate tumor cells to HGF stimulates the PI3-kinase and MAPK pathways, leading to increased scattering, motility, and invasion, which was prevented by the addition of EGCG. EGCG acted at the level of preventing phosphorylation of tyrosines 1234/1235 in the kinase domain of the c-Met receptor without effecting dimerization. HGF-induced changes were independent of the formation of reactive oxygen species, suggesting that EGCG functioned independent of its antioxidant ability. ECG, another tea polyphenol, was as effective as EGCG, while EGC and EC were less effective. EGCG added up to 4 h after the addition of HGF still blocked cell scattering and reduced the HGF-induced phosphorylation of c-Met, Akt, and Erk, suggesting that EGCG could act both by preventing activation of c-Met by HGF and by attenuating the activity of pathways already induced by HGF. HGF did not activate the MAPK and PI3-K pathways in cells treated with methyl-beta-cyclodextrin (mCD) to remove cholesterol. Furthermore, subcellular fractionation approaches demonstrated that only phosphorylated c-Met accumulated in Triton X-100 membrane insoluble fractions, supporting a role for lipid rafts in regulating c-Met signaling. Finally, EGCG treatment inhibited DiIC16 incorporation into membrane lipid ordered domains, and cholesterol partially inhibited the EGCG effects on signaling. Together, these results suggest that green tea polyphenols with the R1 galloyl group prevent activation of the c-Met receptor by altering the structure or function of lipid rafts.

Topics: Anticarcinogenic Agents; Antioxidants; beta-Cyclodextrins; Catechin; Cell Movement; Cells; Flavonoids; Humans; Male; Octoxynol; Phenols; Phosphatidylinositol 3-Kinases; Phosphorylation; Polyphenols; Prostatic Neoplasms; Proto-Oncogene Proteins c-akt; Signal Transduction; Tea

We have previously shown that modification of polyphenols with a ferrocenyl group can dramatically enhance their cytotoxicity. We now present two new [3]ferrocenophane compounds, one of which has an antiproliferative effect seven times stronger than the corresponding noncyclic species, with IC50 values of 90 and 94 nM on hormone-independent MDA-MB-231 breast and PC-3 prostate cancer cell lines, respectively. Solubility studies in water using methylated beta-cyclodextrin and electron transfer studies are also presented.

Topics: Antineoplastic Agents; beta-Cyclodextrins; Breast Neoplasms; Cell Line, Tumor; Female; Flavonoids; Humans; Male; Phenols; Polyphenols; Prostatic Neoplasms; Structure-Activity Relationship

Lipid rafts are cholesterol-enriched microdomains in cell membranes that have been shown to regulate signal transduction. We investigated whether membrane cholesterol could regulate apoptosis and attempted to elucidate the mechanism by which apoptosis is induced in prostate cancer cells.. LNCaP cells were exposed to 2-hydroxyprophyl-beta-cyclodextrin (HPCD) to deplete membrane cholesterol. Cell viability and apoptosis were evaluated by Celltiter Bluetrade mark Cell Viability assay and ethidium bromide/acridine orange staining. Signal transduction was investigated by immunoblot analysis of cell lysates.. Cell viability was dose dependent inhibited by HPCD and restored by replenishment of cholesterol. HPCD induced apoptotic cell death through down-regulation of Bcl-xL and up-regulation of caspase-3 and PARP cleavages. HPCD inhibited both EGFR/Akt and EGFR/ERK signal transduction.. Lipid raft cholesterol regulates apoptotic cell death in prostate cancer cells through EGFR-mediated Akt and ERK pathways.

Topics: 2-Hydroxypropyl-beta-cyclodextrin; Apoptosis; bcl-X Protein; beta-Cyclodextrins; Caspase 3; Cell Line, Tumor; Cell Survival; Cholesterol; Dose-Response Relationship, Drug; Down-Regulation; ErbB Receptors; Extracellular Signal-Regulated MAP Kinases; Humans; Male; Membrane Microdomains; Prostatic Neoplasms; Proto-Oncogene Proteins c-akt; Signal Transduction; Up-Regulation

Prostasomes are vesicles secreted by epithelial cells of the prostate gland. However, little is known about the mechanism and the regulation of prostasome secretion. Since endocytic organelles may be involved in prostasome release, PC-3-derived prostasomes were investigated by Western blot analysis for the presence of marker proteins normally associated with these organelles. Prostasomes secreted by PC-3 cells contain clathrin, Tsg101, Hrs, Rab11, Rab5, LAMP-1, LAMP-2, LAMP-3/CD63, and annexin II. Moreover, electron microscopy of PC-3 cells revealed the presence of characteristic multivesicular body-like secretory lysosomes containing vesicles with the same size-distribution as released prostasomes. Ultrastructural immunogold labelling showed that LAMP-1, LAMP-2 and LAMP-3/CD63 were associated with these vesicles. In addition, we have investigated whether cholesterol plays a role in prostasome release by the human prostate cancer cell line PC-3. Interestingly, prostasome release was significantly increased when the cholesterol levels of PC-3 cells were reduced by the cholesterol-sequestering agent methyl-beta-cyclodextrin (MBCD), or by treatment with lovastatin and mevalonate. In conclusion, these studies indicate that cholesterol plays an important role in the release of prostasomes by the human prostate cancer PC-3 cells, and suggest that prostasomes may be released after fusion of secretory lysosomes with the plasma membrane.

Topics: beta-Cyclodextrins; Cell Line, Tumor; Cholesterol; Endocytosis; Humans; Lovastatin; Lysosomes; Male; Mevalonic Acid; Neoplasm Proteins; Prostatic Neoplasms; Secretory Vesicles

Lipid rafts/caveolae are membrane platforms for signaling molecules that regulate various cellular functions, including cell survival. To better understand the role of rafts in tumor progression and therapeutics, we investigated the effect of raft disruption on cell viability and compared raft levels in human cancer cell lines versus their normal counterparts. Here, we report that cholesterol depletion using methyl-beta cyclodextrin caused anoikis-like apoptosis, which in A431 cells involved decreased raft levels, Bcl-xL down-regulation, caspase-3 activation, and Akt inactivation regardless of epidermal growth factor receptor activation. Cholesterol repletion replenished rafts on the cell surface and restored Akt activation and cell viability. Moreover, the breast cancer and the prostate cancer cell lines contained more lipid rafts and were more sensitive to cholesterol depletion-induced cell death than their normal counterparts. These results indicate that cancer cells contain increased levels of rafts and suggest a potential use of raft-modulating agents as anti-cancer drugs.

Topics: Apoptosis; bcl-X Protein; beta-Cyclodextrins; Breast Neoplasms; Carcinoma, Squamous Cell; Caspase 3; Caspases; Cell Line, Tumor; Cell Survival; Cholesterol; Down-Regulation; Enzyme Activation; ErbB Receptors; Female; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Male; Membrane Microdomains; Neoplasms; Prostatic Neoplasms; Proto-Oncogene Proteins c-akt; Signal Transduction; Simvastatin