Sex differences in the clinical manifestations related to dependence behaviors in medication-overuse headache.

OBJECTIVE: The present study aimed to compare sex differences in the clinical manifestations related to dependence behaviors in medication-overuse headache (MOH). METHODS: Consecutive patients with newly diagnosed chronic migraine (CM) with and without MOH based on the Third Edition of International Classification of Headache Disorders (ICHD-3) were enrolled prospectively from the headache clinic of a tertiary medical center. Demographics and clinical profiles were collected by using a questionnaire, which included current use of tobacco, alcohol, and caffeinated beverages, the Leeds Dependence Questionnaire (LDQ), the Severity of Dependence Scale (SDS), the Headache Impact Test-6 (HIT-6), and the Pittsburgh Sleep Quality Index (PSQI). RESULTS: In total, 1419 CM patients (1135F/284 M, mean age 41.7 ± 13.9 years) were recruited, including 799 with MOH (640F/159 M, mean age 42.5 ± 13.2 years) (56.3%). Smoking was associated with an increased risk for MOH in men (odds ratio [OR] = 3.60 [95% confidence interval = 1.73-7.50], p = 0.001), but not in women (OR = 1.34 [0.88-2.04], p = 0.171) (p = 0.021 for interaction). Hypnotic use ≥ 3 days/week was a risk factor for MOH (OR = 2.55 [95% confidence interval = 2.00-3.24], p < 0.001), regardless of sex. By using receiver operating characteristics (ROC) curves, the cutoff scores of the LDQ for MOH were determined at 7 for women and 6 for men, and those for the SDS were 5 and 4, respectively (area under curve all ≥ 0.83). Among patients with MOH, the male sex was associated with a shorter latency between migraine onset and CM onset (12.9 ± 11.1 vs. 15.4 ± 11.5 years, p = 0.008), despite less average headache intensity (6.7 ± 1.9 vs. 7.2 ± 1.9, p = 0.005), functional impacts (HIT-6: 63.4 ± 8.3 vs. 65.1 ± 8.0, p = 0.009), and sleep disturbances (PSQI: 10.9 ± 4.4 vs. 12.2 ± 4.3, p = 0.001). CONCLUSIONS: The current study identified an association between smoking and MOH in men, as well as sex-specific cutoffs of the LDQ and the SDS, for MOH. MOH was characterized by a shorter latency between migraine onset and CM onset in men and a more severe phenotype in women. Sex should be considered as an important factor in the evaluation of MOH.

Clinical Utility of Leeds Dependence Questionnaire in Medication-Overuse Headache.

Dependence behaviors are common in patients with medication-overuse headache (MOH). This prospective study aimed to characterize dependence behaviors in MOH by using Leeds dependence questionnaire (LDQ), and to determine the clinical utility of LDQ in the diagnosis of MOH. In total, 563 consecutive chronic migraine (CM) patients (451F/112M, mean age 41.7 ± 12.0 years) were recruited, including 320 with MOH (56.8%) (254F/66M, mean age 42.3 ± 11.6 years). LDQ scores were positively correlated with the monthly frequency of acute medication use (Spearman's rho = 0.680, p < 0.001). When compared with patients without, those with MOH scored higher on LDQ (13.0 ± 7.6 vs. 3.9 ± 5.1, p < 0.001). By using a receiver operating characteristics curve, the cutoff value of LDQ was determined at 7 (sensitivity = 77.5%, specificity = 77.4%, area under curve = 0.85) for a diagnosis of MOH. An LDQ score of ≥7 was predictive of MOH (odds ratio = 11.80, 95% confidence interval = 7.87-17.67, p < 0.001). In conclusion, the presence of MOH in patients with CM is associated with more severe dependence behaviors. An LDQ score of ≥7 is useful in the detection of MOH in CM patients.

Effect of Tantalum Pentoxide Addition on the Radiopacity Performance of Bi2O3/Ta2O5 Composite Powders Prepared by Mechanical Milling.

Among the various phases of bismuth oxide, the high temperature metastable face-centered cubic δ phase attracts great attention due to its unique properties. It can be used as an ionic conductor or an endodontic radiopacifying material. However, no reports concerning tantalum and bismuth binary oxide prepared by high energy ball milling and serving as a dental radiopacifier can be found. In the present study, Ta2O5-added Bi2O3 composite powders were mechanically milled to investigate the formation of these metastable phases. The as-milled powders were examined by X-ray diffraction and scanning electron microscopy to reveal the structural evolution. The as-milled composite powders then served as the radiopacifier within mineral trioxide aggregates (i.e., MTA). Radiopacity performance, diametral tensile strength, setting times, and biocompatibility of MTA-like cements solidified by deionized water, saline, or 10% calcium chloride solution were investigated. The experimental results showed that subsequent formation of high temperature metastable ß-Bi7.8Ta0.2O12.2, δ-Bi2O3, and δ-Bi3TaO7 phases can be observed after mechanical milling of (Bi2O3)95(Ta2O5)5 or (Bi2O3)80(Ta2O5)20 powder mixtures. Compared to its pristine Bi2O3 counterpart with a radiopacity of 4.42 mmAl, long setting times (60 and 120 min for initial and final setting times) and 84% MG-63 cell viability, MTA-like cement prepared from (Bi2O3)95(Ta2O5)5 powder exhibited superior performance with a radiopacity of 5.92 mmAl (the highest in the present work), accelerated setting times (the initial and final setting time can be shortened to 25 and 40 min, respectively), and biocompatibility (94% cell viability).

Association between suicidal risks and medication-overuse headache in chronic migraine: a cross-sectional study.

BACKGROUND: Behaviors of substance dependence are common among patients with medication-overuse headache (MOH). Whether MOH, like other substance use disorders, is associated with an increased risk for suicide is unknown. METHODS: In this cross-sectional study, newly diagnosed chronic migraine (CM) patients with or without coexisting MOH were enrolled prospectively. Headache diagnoses were made through face-to-face interviews by headache specialists, and a specifically designed questionnaire was used to collect demographics, headache profiles, Migraine Disability Assessment, Hospital Anxiety and Depression Scale, Pittsburgh Sleep Quality Index, etc. Suicidal ideation and prior suicide attempt were specifically questioned. RESULTS: In total, 603 CM patients (485F/118M, mean age 42.03 ± 12.18 years) were recruited, including 320 with MOH (257F/63M, mean age 42.8 ± 11.7 years) (53.1%), and 214 (35.5%) and 81 (13.4%) had suicidal ideation and prior suicide attempt, respectively. Among CM patients, the presence of MOH increased the risks of suicidal ideation (odds ratio [OR] = 1.75 [95% CI = 1.20-2.56], p = 0.004) and prior suicide attempt (OR = 1.88 [1.09-3.24], p = 0.024), after controlling for demographics, headache profile, disabilities, symptoms of anxiety and depression, and sleep quality. CONCLUSIONS: In CM patients, MOH is associated with an increased risk for suicidal ideation and prior suicide attempt, which deserves attention for clinicians taking care of headache patients. However, further studies are needed to determine the causal relationship, as well as the underlying pathophysiology.

The Fabrication and Characterization of InAlAs/InGaAs APDs Based on a Mesa-Structure with Polyimide Passivation.

This paper presents a novel front-illuminated InAlAs/InGaAs separate absorption, grading, field-control and multiplication (SAGFM) avalanche photodiodes (APDs) with a mesa-structure for high speed response. The electric fields in the InAlAs-multiplication layer and InGaAs-absorption layer enable high multiplication gain and high-speed response thanks to the thickness and concentration of the field-control and multiplication layers. A mesa active region of 45 micrometers was defined using a bromine-based isotropic wet etching solution. The side walls of the mesa were subjected to sulfur treatment before being coated with a thick polyimide layer to reduce current leakage, while lowering capacitance and increasing response speeds. The breakdown voltage (VBR) of the proposed SAGFM APDs was approximately 32 V. Under reverse bias of 0.9 VBR at room temperature, the proposed device achieved dark current of 31.4 nA, capacitance of 0.19 pF and multiplication gain of 9.8. The 3-dB frequency response was 8.97 GHz and the gain-bandwidth product was 88 GHz. A rise time of 42.0 ps was derived from eye-diagrams at 0.9 VBR. There was notable absence of intersymbol-interference and the signals remained error-free at data-rates of up to 12.5 Gbps.

Fabrication and Characterization of Planar-Type Top-Illuminated InP-Based Avalanche Photodetector on Conductive Substrate with Operating Speeds Exceeding 10 Gbps.

This paper presents a high-speed top-illuminated InP-based avalanche photodetector (APD) fabricated on conductive InP-wafer using planar processes. The proposed device was then evaluated in terms of DC and dynamic performance characteristics. The design is based on a separate absorption, grading, charge, and multiplication (SAGCM) epitaxial-structure. An electric field-profile of the SAGCM layers was derived from the epitaxial structure. The punch-through voltage of the SAGCM APD was controlled to within 16⁻17 V, whereas the breakdown voltage (VBR) was controlled to within 28⁻29 V. We obtained dark current of 2.99 nA, capacitance of 0.226 pF, and multiplication gain of 12, when the APD was biased at 0.9 VBR at room temperature. The frequency-response was characterized by comparing the calculated 3-dB cut-off modulation-frequency (f3-dB) and f3-dB values measured under various multiplication gains and modulated incident powers. The time-response of the APD was evaluated by deriving eye-diagrams at 0.9 VBR using pseudorandom non-return to zero codes with a length of 231-1 at 10⁻12.5 Gbps. There was a notable absence of intersymbol-interference, and the signals remained error-free at data-rates of up to 12.5 Gbps. The correlation between the rise-time and modulated-bandwidth demonstrate the suitability of the proposed SAGCM-APD chip for applications involving an optical-receiver at data-rates of >10 Gbps.

Discovery of aliphatic-chain hydroxamates containing indole derivatives with potent class I histone deacetylase inhibitory activities.

Histone deacetylase (HDAC) is a validated drug target for various diseases. This study combined indole recognition cap with SAHA, an FDA-approved HDAC inhibitor used to treat cutaneous T-cell lymphoma (CTCL). The structure activity relationship of the resulting compounds that inhibited HDAC was disclosed as well. Some compounds exhibited much stronger inhibitory activities than SAHA. We identified two meta-series compounds 6j and 6k with a two-carbon linker had IC50 values of 3.9 and 4.5 nM for HDAC1, respectively. In contrast, the same oriented compounds with longer carbon chain linkers showed weaker inhibition. The result suggests that the linker chain length greatly contributed to enzyme inhibitory potency. In addition, comparison of enzyme-inhibiting activity between the compounds and SAHA showed that compounds 6j and 6k displayed higher inhibiting activity for class I (HDAC1, -2, -3 and -8). The molecular docking and structure analysis revealed structural differences with the inhibitor cap and metal-binding regions between the HDAC isozymes that affect interactions with the inhibitors and play a key role for selectivity. Further biological evaluation showed multiple cellular effects associated with compounds 6j- and 6k-induced HDAC inhibitory activity.

Phosphodiesterase Type 5 (PDE5) Inhibitors Sensitize Topoisomerase II Inhibitors in Killing Prostate Cancer Through PDE5-Independent Impairment of HR and NHEJ DNA Repair Systems.

Human castration-resistant prostate cancer (CRPC) is a significant target of clinical research. The use of DNA-damaging agents has a long history in cancer chemotherapy but is limited by their toxicities. The combination with a safer drug can be a strategy in reducing dosage and toxicity while increasing anticancer activity in CRPC treatment. Phosphodiesterase type 5 (PDE5) inhibitors are used to treat erectile dysfunction through the selective inhibition of PDE5 that is responsible for cGMP degradation in the corpus cavernosum. Several studies have reported that PDE5 inhibitors display protective effect against doxorubicin-induced cardiotoxicity. The combinatory treatment of CRPC with doxorubicin and PDE5 inhibitors has been studied accordingly. The data demonstrated that sildenafil or vardenafil (two structure-related PDE5 inhibitors) but not tadalafil (structure-unrelated to sildenafil) sensitized doxorubicin-induced apoptosis in CRPC cells with deteriorating the down-regulation of anti-apoptotic Bcl-2 family members, including Bcl-xL and Mcl-1, and amplifying caspase activation. Homologous recombination (HR) and non-homologous end joining (NHEJ) DNA repair systems were inhibited in the apoptotic sensitization through detection of nuclear foci formation of Rad51 and DNA end-binding of Ku80. PDE5 knockdown to mimic the exposure to PDE5 inhibitors did not reproduce apoptotic sensitization, suggesting a PDE5-independent mechanism. Not only doxorubicin, sildenafil combined with other inhibitors of topoisomerase II but not topoisomerase I also triggered apoptotic sensitization. In conclusion, the data suggest that sildenafil and vardenafil induce PDE5-independent apoptotic sensitization to doxorubicin (or other topoisomerase II inhibitors) through impairment of both HR and NHEJ repair systems that are evident by a decrease of nuclear Rad51 levels and their foci formation in the nucleus, and an inhibition of Ku80 DNA end-binding capability. The combinatory treatment may enable an important strategy for anti-CRPC development.

Enantiomerically pure ß-dipeptide derivative induces anticancer activity against human hormone-refractory prostate cancer through both PI3K/Akt-dependent and -independent pathways.

The use of peptides that target cancer cells and induce anticancer activities through various mechanisms is developing as a potential anticancer strategy. KUD983, an enantiomerically pure ß-dipeptide derivative, displays potent activity against hormone-refractory prostate cancer (HRPC) PC-3 and DU145 cells with submicromolar IC50. KUD983 induced G1 arrest of the cell cycle and subsequent apoptosis associated with down-regulation of several related proteins including cyclin D1, cyclin E and Cdk4, and the de-phosphorylation of RB. The levels of nuclear and total c-Myc protein, which could increase the expression of both cyclin D1 and cyclin E, were profoundly inhibited by KUD983. Furthermore, it inhibited PI3K/Akt and mTOR/p70S6K/4E-BP1 pathways, the key signaling in multiple cellular functions. The transient transfection of constitutively active myristylated Akt (myr-Akt) cDNA significantly rescued KUD983-induced caspase activation but did not blunt the inhibition of mTOR/p70S6K/4E-BP1 signaling cascade suggesting the presence of both Akt-dependent and -independent pathways. Moreover, KUD983-induced effect was enhanced with the down-regulation of anti-apoptotic Bcl-2 members (e.g., Bcl-2, and Mcl-1) and IAP family members (e.g., survivin). Notably, KUD983 induced autophagic cell death using confocal microscopic examination, tracking the level of conversion of LC3-I to LC3-II and flow cytometric detection of acidic vesicular organelles-positive cells. In conclusion, the data suggest that KUD983 is an anticancer ß-dipeptide against HRPCs through the inhibition of cell proliferation and induction of apoptotic and autophagic cell death. The suppression of signaling pathways regulated by c-Myc, PI3K/Akt and mTOR/p70S6K/4E-BP1 and the collaboration with down-regulation of Mcl-1 and survivin may explain KUD983-induced anti-HRPC mechanism.

Non-immunosuppressive triazole-based small molecule induces anticancer activity against human hormone-refractory prostate cancers: the role in inhibition of PI3K/AKT/mTOR and c-Myc signaling pathways.

A series of triazole-based small molecules that mimic FTY720-mediated anticancer activity but minimize its immunosuppressive effect have been produced. SPS-7 is the most effective derivative displaying higher activity than FTY720 in anti-proliferation against human hormone-refractory prostate cancer (HRPC). It induced G1 arrest of cell cycle and subsequent apoptosis in thymidine block-mediated synchronization model. The data were supported by a decrease of cyclin D1 expression, a dramatic increase of p21 expression and an associated decrease in RB phosphorylation. c-Myc overexpression replenished protein levels of cyclin D1 indicating that c-Myc was responsible for cell cycle regulation. PI3K/Akt/mTOR signaling pathways through p70S6K- and 4EBP1-mediated translational regulation are critical to cell proliferation and survival. SPS-7 significantly inhibited this translational pathway. Overexpression of Myr-Akt (constitutively active Akt) completely abolished SPS-7-induced inhibitory effect on mTOR/p70S6K/4EBP1 signaling and c-Myc protein expression, suggesting that PI3K/Akt serves as a key upstream regulator. SPS-7 also demonstrated substantial anti-tumor efficacy in an in vivo xenograft study using PC-3 mouse model. Notably, FTY720 but not SPS-7 induced a significant immunosuppressive effect as evidenced by depletion of marginal zone B cells, down-regulation of sphingosine-1-phosphate receptors and a decrease in peripheral blood lymphocytes. In conclusion, the data suggest that SPS-7 is not an immunosuppressant while induces anticancer effect against HRPC through inhibition of Akt/mTOR/p70S6K pathwaysthat down-regulate protein levels of both c-Myc and cyclin D1, leading to G1 arrest of cell cycle and subsequent apoptosis. The data also indicate the potential of SPS-7 since PI3K/Akt signalingis responsive for the genomic alterations in prostate cancer.

Menthols as Chiral Auxiliaries for Asymmetric Cycloadditive Oligomerization: Syntheses and Studies of ß-Proline Hexamers.

To produce a novel class of structurally ordered poly-ß-prolines, an emergent method for synthesizing chiral ß-peptide molecular frameworks was developed based on 1,3-dipolar cycloaddition chemistry of azomethine ylides. Functionalized short ß-peptides with up to six monomeric residues were efficiently synthesized in homochiral forms using a cycloadditive oligomerization approach. X-ray, NMR, and CD structural analyses of the novel ß-peptides revealed secondary structure features that were generated primarily by Z/E-ß-peptide bond isomerism. Anticancer in cellulo activity of the new ß-peptides toward hormone-refractory prostate cancer cells was observed and was dependent on the absolute configuration of the stereogenic centers and the chain length of the ß-proline oligomers.

Epi-reevesioside F inhibits Na+/K+-ATPase, causing cytosolic acidification, Bak activation and apoptosis in glioblastoma.

Epi-reevesioside F, a new cardiac glycoside isolated from the root of Reevesia formosana, displayed potent activity against glioblastoma cells. Epi-reevesioside F was more potent than ouabain with IC50 values of 27.3±1.7 vs. 48.7±1.8 nM (P < 0.001) and 45.0±3.4 vs. 81.3±4.3 nM (P < 0.001) in glioblastoma T98 and U87 cells, respectively. However, both Epi-reevesioside F and ouabain were ineffective in A172 cells, a glioblastoma cell line with low Na+/K+-ATPase α3 subunit expression. Epi-reevesioside F induced cell cycle arrest at S and G2 phases and apoptosis. It also induced an increase of intracellular concentration of Na+ but not Ca2+, cleavage and exposure of N-terminus of Bak, loss of mitochondrial membrane potential, inhibition of Akt activity and induction of caspase cascades. Potassium supplements significantly inhibited Epi-reevesioside F-induced effects. Notably, Epi-reevesioside F caused cytosolic acidification that was highly correlated with the anti-proliferative activity. In summary, the data suggest that Epi-reevesioside F inhibits Na+/K+-ATPase, leading to overload of intracellular Na+ and cytosolic acidification, Bak activation and loss of mitochondrial membrane potential. The PI3-kinase/Akt pathway is inhibited and caspase-dependent apoptosis is ultimately triggered in Epi-reevesioside F-treated glioblastoma cells.

KUD773, a phenylthiazole derivative, displays anticancer activity in human hormone-refractory prostate cancers through inhibition of tubulin polymerization and anti-Aurora A activity.

BACKGROUND: Hormone-refractory prostate cancer (HRPC), which is resistant to hormone therapy, is a major obstacle in clinical treatment. An approach to inhibit HRPC growth and ultimately to kill cancers is highly demanded. RESULTS: KUD773 induced the anti-proliferative effect and subsequent apoptosis in PC-3 and DU-145 (two HRPC cell lines); whereas, it showed less active in normal prostate cells. Further examination showed that KUD773 inhibited tubulin polymerization and induced an increase of mitotic phosphoproteins and polo-like kinase 1 (PLK1) phosphorylation, indicating a mitotic arrest of the cell cycle through an anti-tubulin action. The kinase assay demonstrated that KUD773 inhibited Aurora A activity. KUD773 induced an increase of Cdk1 phosphorylation at Thr(161) (a stimulatory phosphorylation site) and a decrease of phosphorylation at Tyr(15) (an inhibitory phosphorylation site), suggesting the activation of Cdk1. The data were substantiated by an up-regulation of cyclin B1 (a Cdk1 partner). Furthermore, KUD773 induced the phosphorylation and subsequent down-regulation of Bcl-2 and activation of caspase cascades. CONCLUSIONS: The data suggest that KUD773 induces apoptotic signaling in a sequential manner. It inhibits tubulin polymerization associated with an anti-Aurora A activity, leading to Cdk1 activation and mitotic arrest of the cell cycle that in turn induces Bcl-2 degradation and a subsequent caspase activation in HRPCs.

Tubulin-binding agents down-regulate matrix metalloproteinase-2 and -9 in human hormone-refractory prostate cancer cells ­ a critical role of Cdk1 in mitotic entry.

Tubulin is an important target for anticancer therapy. Taxanes and vinca alkaloids are two groups of tubulin-binding agents in cancer chemotherapy. Besides tubulin binding, these groups of agents can also down-regulate protein levels of matrix metalloproteinase (MMP)-2 and -9, two important cancer-associated zinc-dependent endopeptidases in invasion and metastasis. However, the mechanism of action waits to be explored. In this study, protein levels but not mRNA expressions of MMP-2 and -9 were down-regulated by paclitaxel (a microtubule-stabilization agent), vincristine and evodiamine (two tubulin-depolymerization agents). These agents induced an increase of protein expression of cyclin B1, MPM2 (mitosis-specific phosphoprotein) and polo-like kinase (PLK) 1 phosphorylation. The data showed a negative relationship between the levels of mitotic proteins and MMP-2 and -9 expressions. MG132 (a specific cell-permeable proteasome inhibitor) blocked mitotic entry and arrested cell cycle at G2 phase, preventing down-regulation of MMP-2 and -9. Cell cycle synchronization experiments by thymidine block or nocodazole treatment showed that mitotic exit inhibited the down-regulation of MMP-2 and -9, confirming negative relationship between cell mitosis and protein levels of MMP-2 and -9 expressions. Cyclin-dependent kinase (Cdk) 1 is a key kinase in mitotic entry. Knockdown of Cdk1 almost completely inhibited the down-regulation of MMP-2 and -9 induced by tubulin-binding agents. In conclusion, the data suggest that mitotic entry and Cdk1 plays a central role in down-regulation of MMP-2 and -9 protein expressions. Tubulin-binding agents cause mitotic arrest and Cdk1 activation, which may contribute largely to the down-regulation of both MMP-2 and -9 expressions.

Structural studies and anticancer activity of a novel class of ß-peptides.

Functionalized oligomeric organic compounds with well-defined ß-proline scaffold have been synthesized by a cycloadditive oligomerization approach in racemic and enantiopure forms. The structure of the novel ß-peptides was investigated by NMR spectroscopic and X-ray methods determining the conformational shapes of the ß-proline oligomers in solution and solid states. The main structural elements subject to conformational switches are ß-peptide bonds between 5-arylpyrrolidine-2-carboxylic acid units existing in Z/E configurations. The whole library of short ß-peptides and intermediate acrylamides has been tested on antiproliferative activity towards the hormone-refractory prostate cancer cell line PC-3 revealing several oligomeric compounds with low micromolar and submicromolar activities. Bromine-substituted dimeric and trimeric acrylamides induced caspase-dependent apoptosis of PC-3 cells through cell-cycle arrest and mitochondrial damage.

A novel small molecule hybrid of vorinostat and DACA displays anticancer activity against human hormone-refractory metastatic prostate cancer through dual inhibition of histone deacetylase and topoisomerase I.

Vorinostat, which is an extensively studied inhibitor against histone deacetylase (HDAC), shows limited clinical activity to solid tumors. WJ35435, a new hybrid of vorinostat and DACA (a topoisomerase inhibitor) potently inhibited HDAC activity (in particular HDAC1 and HDAC6) in kinase assay and cell-based examination. The anti-HDAC effect was confirmed by the induction of histone H3 acetylation and phosphorylation, α-tubulin acetylation and γ-H2AX formation. WJ35435 showed better potency than vorinostat and DACA against PC-3 and DU-145, two human hormone-refractory metastatic prostate cancer (HRMPC) cell lines, but not benign prostate cells. WJ35435 at differential concentrations induced G1- or G2-phase arrest of the cell cycle in HRMPCs but not in benign prostate cells. WJ35435 induced the formation of topoisomerase I-DNA cleavable complexes but not type-IIα or -IIß. Topoisomerase activity assay confirmed the selective inhibition of topoisomerase I. WJ35435 induced profound DNA damage using comet tailing assay. WJ35435 was less effective than camptothecin and etoposide in inducing the phosphorylation and activation of Chk1, Chk2 and RPA32 which were crucial coordinators in DNA repair pathway, indicating a low DNA repair activity to WJ35435 action. Furthermore, WJ35435 showed an in vivo antitumor activity. A synergistic apoptosis (combination index=0.55) was obtained in combination between WJ35435 and MG-132 (a proteasome inhibitor). In summary, WJ35435 is a dual-targeted anticancer hybrid induces anti-HDAC and anti-topoisomerase I activities that cause DNA damage associated with a low DNA repair capability, and induce cell cycle arrest at G1- and G2-phase. Ultimately, WJ35435 inhibits cell proliferation and induces apoptosis of HRMPCs.

Reevesioside A, a cardenolide glycoside, induces anticancer activity against human hormone-refractory prostate cancers through suppression of c-myc expression and induction of G1 arrest of the cell cycle.

In the past decade, there has been a profound increase in the number of studies revealing that cardenolide glycosides display inhibitory activity on the growth of human cancer cells. The use of potential cardenolide glycosides may be a worthwhile approach in anticancer research. Reevesioside A, a cardenolide glycoside isolated from the root of Reevesia formosana, displayed potent anti-proliferative activity against human hormone-refractory prostate cancers. A good correlation (r²â€Š= 0.98) between the expression of Na⁺/K⁺-ATPase α3 subunit and anti-proliferative activity suggested the critical role of the α3 subunit. Reevesioside A induced G1 arrest of the cell cycle and subsequent apoptosis in a thymidine block-mediated synchronization model. The data were supported by the down-regulation of several related cell cycle regulators, including cyclin D1, cyclin E and CDC25A. Reevesioside A also caused a profound decrease of RB phosphorylation, leading to an increased association between RB and E2F1 and the subsequent suppression of E2F1 activity. The protein and mRNA levels of c-myc, which can activate expression of many downstream cell cycle regulators, were dramatically inhibited by reevesioside A. Transient transfection of c-myc inhibited the down-regulation of both cyclin D1 and cyclin E protein expression to reevesioside A action, suggesting that c-myc functioned as an upstream regulator. Flow cytometric analysis of JC-1 staining demonstrated that reevesioside A also induced the significant loss of mitochondrial membrane potential. In summary, the data suggest that reevesioside A inhibits c-myc expression and down-regulates the expression of CDC25A, cyclin D1 and cyclin E, leading to a profound decrease of RB phosphorylation. G1 arrest is, therefore, induced through E2F1 suppression. Consequently, reevesioside A causes mitochondrial damage and an ultimate apoptosis in human hormone-refractory prostate cancer cells.

Terfenadine induces anti-proliferative and apoptotic activities in human hormone-refractory prostate cancer through histamine receptor-independent Mcl-1 cleavage and Bak up-regulation.

Although the results of several studies have underscored the regulatory effect of H1-histamine receptors in cell proliferation of some cancer cell types, its effect in prostate cancers remains unclear. We have therefore studied the effect of terfenadine (an H1-histamine receptor antagonist) in prostate cancer cell lines. Our data demonstrate that terfenadine was effective against PC-3 and DU-145 cells (two prostate cancer cell lines). In contrast, based on the sulforhodamine B assay, loratadine had less potency while fexofenadine and diphenhydramine had little effect. Terfenadine induced the cleavage of Mcl-1 cleavage into a pro-apoptotic 28-kDa fragment and up-regulation of Bak, resulting in the loss of mitochondrial membrane potential (ΔΨm) and the release of cytochrome c and apoptosis-inducing factor into the cytosol. The activation of caspase cascades was detected to be linked to terfenadine action. Bak up-regulation was also examined at both the transcriptional and translational levels, and Bak activation was validated based on conformational change to expose the N terminus. Terfenadine also induced an indirect-but not direct-DNA damage response through the cleavage and activation of caspase-2, phosphorylation and activation of Chk1 and Chk2 kinases, phosphorylation of RPA32 and acetylation of Histone H3; these processes were highly correlated to severe mitochondrial dysfunction and the activation of caspase cascades. In conclusion, terfenadine induced apoptotic signaling cascades against HRPCs in a sequential manner. The exposure of cells to terfenadine caused the up-regulation and activation of Bak and the cleavage of Mcl-1, leading to the loss of ΔΨm and activation of caspase cascades which further resulted in DNA damage response and cell apoptosis.

A novel hydroxysuberamide derivative potentiates MG132-mediated anticancer activity against human hormone refractory prostate cancers--the role of histone deacetylase and endoplasmic reticulum stress.

BACKGROUND: Histone deacetylase (HDAC) inhibitors are successful for treatment of advanced cutaneous T-cell lymphoma but only show modest effect in solid tumors. Approaches for HDAC inhibitors to improve activity against solid tumors are necessary. METHODS: Sulforhodamine B assay and flow cytometric analysis detected cell proliferation and cell-cycle progression, respectively. Protein expression was determined by Western blotting. Comet assay and DNA end-binding activity of Ku proteins detected DNA damage and DNA repair activity, respectively. siRNA technique was used for knockdown of specific cellular target. RESULTS: WJ25591 displayed inhibitory activity against HDAC1 and cell proliferation in human hormone-refractory prostate cancers PC-3 and DU-145. WJ25591 caused an arrest of cell-cycle at both G1- and G2-phase and increased protein expressions of p21 and cyclin E, followed by cell apoptosis. WJ25591-induced Bcl-2 down-regulation and activation of caspase-9, -8, and -3, suggesting apoptotic execution through both intrinsic and extrinsic apoptotic pathways. WJ25591 also significantly inhibited DNA repair activity but not directly induced DNA damage. Moreover, the proteasome inhibitor MG-132 dramatically sensitized WJ25591-induced cell apoptosis. The siRNA technique demonstrated that endoplasmic reticulum (ER) stress, in particular CHOP/GADD153 up-regulation, contributed to the synergistic effect. CONCLUSIONS: The data suggest that WJ25591 inhibited HDAC activity, leading to cell-cycle arrest and inhibition of DNA repair. Caspase cascades are subsequently triggered to execute cell apoptosis. MG-132 dramatically sensitizes WJ25591-mediated apoptosis, at least partly, through ER stress response. The data also reveal that combination of HDAC inhibitors and proteasome inhibitors may be a potential strategy against hormone-refractory prostate cancers.

Synthesis of a chlorogenin glycoside library using an orthogonal protecting group strategy.

Naturally occurring spirostanol saponins bear a chacotriose, α-L-rhamnopyranosyl-(1→2)-[α-L-rhamnopyranosyl-(1→4)]-ß-D-glucopyranose residue as the oligosaccharide moiety which is believed to be important for biological activity. Herein the development of a concise, combinatorial method for the synthesis of two series of glycan variants at the 2' and/or 4' positions of chacotriose is described and the structure-activity relationships of the glycone part at 3-OH of chlorogenin investigated. These compounds were found to be weakly-cytotoxic toward leukemia cell lines CCRF and HL-20, indicating that the chacotriose moiety is important for anticancer activity.