[show abstract][hide abstract] ABSTRACT: Prostate cancer is the second leading cause of cancer deaths among men. For patients with hormone-refractory disease, few treatments are available once the tumor has metastasized beyond the prostate. In the present study, two conjugated lytic peptide sequences (named JCHLHRH and JC21LHRH) were designed to target luteinizing hormone-releasing hormone receptors (LHRH-R). Our results indicate that human prostate cancer cell lines were sensitive to both LHRH-conjugated and non-conjugated lytic peptides, with IC(50) concentrations for LNCaP cells, 4.4 and 9.1μM; for DU-145 cells, 4.8 and 5.7μM; and for PC-3 cells, 4.4 and 8.2μM, respectively. JCHLHRH and JC21LHRH were nontoxic to normal primary human prostate epithelial cells or to bone marrow stromal cells in co-culture. There were morphological changes in PC-3 cells after 3h of exposure to either peptide; after 6h, there were significant reductions in cell numbers. Exposure of PC-3 cells for 24h to either JCHLHRH or JC21LHRH blocked their growth over 3 days. Since JCHLHRH and JC21LHRH have specificity for and anti-proliferative activity against tumor cells, and low toxicity for normal prostate cells, these peptides could serve as a new type of therapy for prostate cancer.
[show abstract][hide abstract] ABSTRACT: Chemoprevention presents a major strategy for the medical management of colorectal cancer. Most drugs used for colorectal cancer therapy induce DNA-alkylation damage, which is primarily repaired by the base excision repair (BER) pathway. Thus, blockade of BER pathway is an attractive option to inhibit the spread of colorectal cancer. Using an in silico approach, we performed a structure-based screen by docking small-molecules onto DNA polymerase β (Pol-β) and identified a potent anti-Pol-β compound, NSC-124854. Our goal was to examine whether NSC-124854 could enhance the therapeutic efficacy of DNA-alkylating agent, Temozolomide (TMZ), by blocking BER. First, we determined the specificity of NSC-124854 for Pol-β by examining in vitro activities of APE1, Fen1, DNA ligase I, and Pol-β-directed single nucleotide (SN)- and long-patch (LP)-BER. Second, we investigated the effect of NSC-124854 on the efficacy of TMZ to inhibit the growth of mismatch repair (MMR)-deficient and MMR-proficient colon cancer cell lines using in vitro clonogenic assays. Third, we explored the effect of NSC-124854 on TMZ-induced in vivo tumor growth inhibition of MMR-deficient and MMR-proficient colonic xenografts implanted in female homozygous SCID mice. Our data showed that NSC-124854 has high specificity to Pol-β and blocked Pol-β-directed SN- and LP-BER activities in in vitro reconstituted system. Furthermore, NSC-124854 effectively induced the sensitivity of TMZ to MMR-deficient and MMR-proficient colon cancer cells both in vitro cell culture and in vivo xenograft models. Our findings suggest a potential novel strategy for the development of highly specific structure-based inhibitor for the prevention of colonic tumor progression.
PLoS ONE 01/2011; 6(2):e16691. · 3.73 Impact Factor
[show abstract][hide abstract] ABSTRACT: Prostate cancer has been widely viewed as a chemoresistant neoplasm. Perhaps, the most prevalent antimicrotubule strategy involves docetaxel administration at its maximum-tolerated dose (MTD). Although the goal is to obtain total eradication of cancer cells, debilitating toxicities are presented by docetaxel therapy, including myelosuppression, immunosuppression, gastrointestinal toxicity and peripheral neuropathy. In addition, solubility limitations necessitate infusion of high-doses intravenously once or twice a week followed by a rest period, which allows recovery of normal proliferating cells to counter-balance efficacy. An emerging notion is that more of a toxic drug at its MTD is not necessarily better. It is likely that combinatorial antimicrotubule therapy with drugs occupying different sites on tubulin may enhance efficacy while reducing toxicity. Here we show that bromonoscapine (EM011), a microtubule-modulating noscapine analog, displays synergism with docetaxel as seen by cell viability and proliferation assays. Cell-cycle data demonstrated that lower dose-levels of docetaxel (25nM) in combination with EM011 caused an additive increase in proapoptotic activity. Since docetaxel alone caused severe mitotic arrest followed by mitotic slippage and endoreduplication, we strategized a sequential treatment regime that involved initial pretreatment with docetaxel followed by addition of EM011 to maximize mitotic arrest and subsequent apoptosis. In vivo studies with docetaxel and EM011 in combination showed a marked inhibition of tumor growth compared to docetaxel or EM011 as single-agents. Our studies suggest the potential usefulness of EM011 in the clinic to enhance docetaxel activity. This would reduce toxicity, thus improving the quality of life of docetaxel-treated patients.
[show abstract][hide abstract] ABSTRACT: The tubulin-binding anticancer activity of noscapine, an orally available plant-derived anti-tussive alkaloid, has been recently identified. Noscapine inhibits tumor growth in nude mice bearing human xenografts of hematopoietic, breast, lung, ovarian, brain and prostate origin. Despite its nontoxic attributes, significant elimination of the disease has not been achieved, perhaps since the bioavailability of noscapine to tumors saturates at an oral dose of 300 mg/kg body weight. To enable the selective and specific delivery of noscapine to prostate cancer cells, we have engineered a multifunctional nanoscale delivery vehicle that takes advantage of urokinase plasminogen activator receptor (uPAR) overexpression in prostate cancer compared to normal prostate epithelia and can be tracked by magnetic resonance imaging (MRI) and near-infrared (NIR) imaging. Specifically, we employed the human-type 135 amino-acid amino-terminal fragment (hATF) of urokinase plasminogen activator (uPA), a high-affinity natural ligand for uPAR. Noscapine (Nos) was efficiently adsorbed onto the amphiphilic polymer coating of uPAR-targeted nanoparticles (NPs). Nos-loaded NPs were uniformly compact-sized, stable at physiological pH and efficiently released the drug at pH 4 to 5 within a span of 4h. Our results demonstrate that these uPAR-targeted NPs were capable of binding to the receptor and were internalized by PC-3 cells. uPAR-targeted Nos-loaded NPs enhanced intracellular noscapine accumulation as evident by the ~6-fold stronger inhibitory effect on PC-3 growth compared to free noscapine. In addition, Nos-loaded iron oxide NPs maintained their T2 MRI contrast effect upon internalization into tumor cells owing to their significant susceptibility effect in cells. Thus, our data provide compelling evidence that these optically and magnetic resonance imaging (MRI)-trackable uPAR-targeted NPs may offer a great potential for image-directed targeted delivery of noscapine for the management of prostate cancer.
Journal of Controlled Release 10/2010; 149(3):314-22. · 7.63 Impact Factor
[show abstract][hide abstract] ABSTRACT: Noscapine (NOS) is a unique class of tubulin-binding anticancer agents. Their potential usefulness as anticancer drugs is however limited by the poor bioavailability, thus necessitating administration of a higher dose regime in the range of 300-600 mg/kg for tumor growth inhibition. To augment bioavailability, we prepared an inclusion complex of NOS in beta-cyclodextrin (beta-CD) and evaluated its physico-chemical characteristics.
Our phase-solubility analysis shows a 1:1-complexation (Kc approximately 0.454 mM(-1)) of NOS with beta-CD that offers better dissolution properties. We confirmed complex formation in solid state by differential scanning calorimetry, powder X-ray diffractometry, Fourier-transform infrared spectroscopy, 1H nuclear magnetic resonance spectroscopy, rotating frame Overhauser enhancement spectroscopy and by molecular modeling methods. Based upon theoretical calculations in gas phase, we propose O-CH2-O- in orientation of NOS in the beta-CD cavity. The thermal behavior data also provides complementary evidences of complex formation. The pharmacokinetic studies showed a 1.87-fold increase in bioavailability of NOS upon complexation in the beta-CD inclusion complex state as compared to free NOS. Furthermore, the complex retains the anticancer attributes of NOS.
Our studies propose for the first time a stable NOS-beta-CD inclusion complex as an effective approach to enhance the solubility and bioavailability of NOS for anticancer therapy.
Cancer Chemotherapy and Pharmacology 08/2010; 65(3):537-48. · 2.80 Impact Factor
[show abstract][hide abstract] ABSTRACT: Autophagy is being increasingly implicated in both cell survival and death. However, the intricate relationships between drug-induced autophagy and apoptosis remain elusive. Here we demonstrate that a tubulin-binding noscapine analog, (R)-9-bromo-5-((S)-4,5-dimethoxy-1,3-dihydroisobenzofuran-1-yl)-4-methoxy-6-methyl-5,6,7,8-tetrahydro-[1,3]-di-oxolo[4,5-g]isoquinoline (Red-Br-nos), exerts a novel autophagic response followed by apoptotic cell death in human prostate cancer PC-3 cells. Red-Br-nos-induced autophagy was an early event detectable within 12 h that displayed a wide array of characteristic features including double membranous vacuoles with entrapped organelles, acidic vesicular organelles, and increased expression of LC3-II and beclin-1. Red-Br-nos-triggered release of reactive oxygen species (ROS) and attenuation of ROS by tiron, a ROS scavenger, reduced the sub-G(1) population suggesting ROS-dependent apoptosis. Abrogation of ROS also reduced autophagy indicating that ROS triggers autophagy. Pharmacological and genetic approaches to inhibit autophagy uncovered the protective role of Red-Br-nos-induced autophagy in PC-3 cells. Direct effects of the drug on mitochondria viz. disruption of normal cristae architecture and dissipation of mitochondrial transmembrane potential revealed a functional link between ROS generation, autophagy, and apoptosis induction. This is the first report to demonstrate the protective role of ROS-mediated autophagy and induction of caspase-independent ROS-dependent apoptosis in PC-3 cells by Red-Br-nos, a member of the noscapinoid family of microtubule-modulating anticancer agents.
Journal of Biological Chemistry 06/2010; 285(24):18737-48. · 4.65 Impact Factor
[show abstract][hide abstract] ABSTRACT: Hormone-refractory prostate cancer, its skeletal metastasis and complications remain a therapeutic challenge. Here we show that treatment with (S)-3-((R)-9-bromo-4-methoxy-6-methyl-5,6,7,8-tetrahydro-[1,3]dioxolo[4,5-g]isoquinolin-5-yl)-6,7-dimethoxyiso-benzofuran-1(3H)-one (EM011), the brominated analogue of a plant-derived non-toxic antitussive alkaloid, noscapine, achieved significant inhibition of hormone-refractory human prostate cancer implanted intratibially in the bone as shown by non-invasive, real-time bioluminescent imaging of tumour growth in nude mice. Mechanistically, in vitro data suggested that the antiproliferative and proapoptotic effects of EM011 in human prostate cancer cell lines were through blockade of cell-cycle progression by impairing the formation of a bipolar spindle apparatus. The G2/M arrest was accompanied by activation of the mitotic checkpoint, a pre-requisite for induction of optimal apoptosis. Attenuation of mitotic checkpoint by siRNA duplexes led to a reduction in mitotic arrest and subsequent apoptosis. Our results further demonstrated participation of an intrinsic mitochondrially mediated apoptotic pathway that ultimately triggered caspase-driven EM011-induced apoptosis. EM011 did not exert any detectable toxicity in normal tissues with frequently dividing cells such as the gut and bone marrow. Thus, these data warrant further evaluation of EM011 for the management of prostate cancer.
European journal of cancer (Oxford, England: 1990) 03/2010; 46(9):1668-78. · 4.12 Impact Factor
[show abstract][hide abstract] ABSTRACT: HS-27a human bone stromal cells, in 2D or 3D coultures, induced cellular plasticity in human prostate cancer ARCaP(E) and ARCaP(M) cells in an EMT model. Cocultured ARCaP(E) or ARCaP(M) cells with HS-27a, developed increased colony forming capacity and growth advantage, with ARCaP(E) exhibiting the most significant increases in presence of bone or prostate stroma cells. Prostate (Pt-N or Pt-C) or bone (HS-27a) stromal cells induced significant resistance to radiation treatment in ARCaP(E) cells compared to ARCaP(M) cells. However pretreatment with anti-E-cadherin antibody (SHEP8-7) or anti-alpha v integrin blocking antibody (CNT095) significantly decreased stromal cell-induced radiation resistance in both ARCaP(E)- and ARCaP(M)-cocultured cells. Taken together the data suggest that mesenchymal-like cancer cells reverting to epithelial-like cells in the bone microenvironment through interaction with bone marrow stromal cells and reexpress E-cadherin. These cell adhesion molecules such as E-cadherin and integrin alpha v in cancer cells induce cell survival signals and mediate resistance to cancer treatments such as radiation.
[show abstract][hide abstract] ABSTRACT: The delivery of noscapine therapies directly to the site of the tumor would ultimately allow higher concentrations of the drug to be delivered, and prolong circulation time in vivo to enhance the therapeutic outcome of this drug. Therefore, we sought to design magnetic based polymeric nanoparticles for the site directed delivery of noscapine to invasive tumors. We synthesized Fe(3)O(4) nanoparticles with an average size of 10 ± 2.5 nm. These Fe(3)O(4) NPs were used to prepare noscapine loaded magnetic polymeric nanoparticles (NMNP) with an average size of 252 ± 6.3 nm. Fourier transform infrared (FT-IR) spectroscopy showed the encapsulation of noscapine on the surface of the polymer matrix. The encapsulation of the Fe(3)O(4) NPs on the surface of the polymer was confirmed by elemental analysis. We studied the drug loading efficiency of polylactide acid (PLLA) and poly (L-lactide acid-co-gylocolide) (PLGA) polymeric systems of various molecular weights. Our findings revealed that the molecular weight of the polymer plays a crucial role in the capacity of the drug loading on the polymer surface. Using a constant amount of polymer and Fe(3)O(4) NPs, both PLLA and PLGA at lower molecule weights showed higher loading efficiencies for the drug on their surfaces.
Journal of Magnetism and Magnetic Materials 01/2010; 322(2):190-196. · 1.83 Impact Factor
[show abstract][hide abstract] ABSTRACT: Noscapine, a plant-derived, non-toxic, over-the-counter antitussive alkaloid has tubulin-binding properties. Based upon the structural resemblance of noscapine to colchicine, a tubulin-binding anti-inflammatory drug, noscapine and its semi-synthetic brominated analogs were examined for in vitro anti-inflammatory activity. Brominated noscapine analogs were found to inhibit cytokine and chemokine release from macrophage cell lines but did not affect cell viability. Brominated noscapine analogs demonstrated anti-inflammatory properties in both TLR- and non-TLR induced in vitro innate immune pathway inflammation models, mimicking septic and sterile infection respectively. In addition, electron microscopy and immunoblotting data indicated that these analogs induced robust autophagy in human macrophages. This study is the first report to identify brominated noscapines as innate immune pathway anti-inflammatory molecules.
PLoS ONE 01/2010; 5(2):e9165. · 3.73 Impact Factor
[show abstract][hide abstract] ABSTRACT: The enantiomers of mandelic acid and its analogs have been chromatographically separated on a chiral stationary phase (CSP) derived from 4-(3,5-dinitrobenzamido) tetrahydrophenanthrene. The rationale of separations of these compounds is discussed with respect to the method development for determining enantiomeric purity and possibility of obtaining enantiomerically pure materials by high-pressure liquid chromatography. The relationship of analyte structure to the extent of enantiomeric separation has been examined and separation factors (alpha) are presented for various groups of structurally related compounds. Chiral recognition models have been suggested to account for the observed separations. These models provide mechanistic insights into the chiral recognition process.
[show abstract][hide abstract] ABSTRACT: (S)-3-((R)-9-bromo-4-methoxy-6-methyl-5,6,7,8-tetrahydro-[1,3]dioxolo[4,5-g]isoquino-lin-5-yl)-6,7-dimethoxyisobenzofuran-1(3H)-one (EM011) is a tubulin-binding agent with significant anticancer activity. Here we show that EM011 modulates microtubule dynamics at concentrations that do not alter the total polymer mass of tubulin. In particular, EM011 decreases the transition frequencies between growth and shortening phases and increases the duration microtubules spend in an idle 'pause' state. Using B16LS9 murine melanoma cells, we show that EM011 briefly arrests cell-cycle progression at the G2/M phase by formation of multiple aster spindles. An aberrant mitotic exit without cytokinesis then occurs, leading to the accumulation of abnormal multinucleated cells prior to apoptosis. Our pharmacokinetic studies conformed to a linear dose-response relationship upto 150 mg/kg. However, non-linearity was observed at 300 mg/kg. In a syngeneic murine model of subcutaneous melanoma, better antitumor responses were seen at 150 mg/kg compared to 300 mg/kg of EM011. Unlike currently available chemotherapeutics, EM011 is non-toxic to normal tissues and most importantly, does not cause any immunosuppression and neurotoxicity. Our data thus warrant a clinical evaluation of EM011 for melanoma therapy.
International Journal of Cancer 08/2009; 126(1):256-65. · 6.20 Impact Factor
[show abstract][hide abstract] ABSTRACT: In the present investigation, we determined the chemotherapeutic efficacy of 9-bromonoscapine (Br-Nos), a more potent noscapine analog, on MCF10A, spontaneously immortalized human normal breast epithelial cells and MCF10A-CSC3, cigarette smoke condensate (CSC)-transformed cells. The results from cytogenetic analysis showed that Br-Nos induced polyploidy and telomeric association in MCF10A-CSC3 cells, while MCF10A cells remained unaffected. Our immunofluorescence data further demonstrated that MCF10A-CSC3 cells were susceptible to mitotic catastrophe on exposure to Br-Nos and failed to recover after drug withdrawal. MCF10A-CSC3 cells exhibited Br-Nos-induced aberrant multipolar spindle formation, which irreversibly impaired the alignment of replicated chromosome to the equatorial plane and finally culminated in cell death. Although MCF10A cells upon Br-Nos treatment showed bipolar spindles with some uncongressed chromosomes, these cells recovered fairly well after drug withdrawal. Our flow-cytometry analysis data reconfirmed that MCF10A-CSC3 cells were more susceptible to cell death compared to MCF10A cells. Furthermore, our results suggest that decreased levels of cdc2/cyclin B1 and cdc2 kinase activity are responsible for Br-Nos-induced mitotic cell arrest leading to cell death in MCF10A-CSC3 cells. This study thus explores the underlying mechanism of Br-Nos-induced mitotic catastrophe in CSC-transformed MCF10A-CSC3 cells and its potential usefulness as a chemotherapeutic agent for prevention of cigarette smoke-induced breast cancer growth.
Journal of Cellular Biochemistry 03/2009; 106(6):1146-56. · 3.06 Impact Factor
[show abstract][hide abstract] ABSTRACT: Lung cancer remains a leading cause of cancer death among both men and women in the United States. Treatment modalities available for this malignancy are inadequate and thus new drugs with improved pharmacological profiles and superior therapeutic indices are being continually explored. Noscapinoids constitute an emerging class of anticancer agents that bind tubulin but do not significantly alter the monomer/polymer ratio of tubulin. EM011, a rationally-designed member of this class of non-toxic agents, is more potent than the lead molecule, noscapine.
Here we report that EM011 inhibited proliferation of a comprehensive panel of lung cancer cells with IC(50)'s ranging from 4-50 microM. In A549 human non-small cell lung cancer cells, the antiproliferative activity was mediated through blockage of cell-cycle progression by induction of a transient but robust mitotic arrest accompanied by activation of the spindle assembly checkpoint. The mitotically-arrested A549 cells then override the activated mitotic checkpoint and aberrantly exit mitosis without cytokinesis resulting in pseudo G1-like multinucleated cells that either succumb directly to apoptosis or continue another round of the cell-cycle. The accumulated enormous DNA perhaps acts as genotoxic stress to trigger cell death. EM011-induced apoptotic cell death in A549 cells was associated with a decrease of the Bcl2/BAX ratio, activation of caspase-3 and cleavage of PARP. Furthermore, EM011 induced downregulation of survivin expression over time of treatment. Abrogation of survivin led to an increase of cell death whereas, overexpression caused decreased apoptosis.
These in vitro data suggest that EM011 mediates antiproliferative and proapoptotic activity in non-small cell A549 lung cancer cells by impeding cell-cycle progression and attenuating antiapoptotic signaling circuitries (viz. Bcl2, survivin). The study provides evidence for the potential usefulness of EM011 in chemotherapy of lung cancer.
Molecular Cancer 01/2009; 8:93. · 5.13 Impact Factor
[show abstract][hide abstract] ABSTRACT: Eg5 is a motor protein of the kinesin family that is critical for spindle assembly during mitosis and has recently been implicated in tumorigenesis. It is largely unknown how Eg5 expression is regulated in cells. In this study, we present the first evidence that the cellular Eg5 level is down-regulated by Parkin, an E3 ubiquitin ligase well known for its role in the development of Parkinson disease. Our data show that Parkin does not trigger Eg5 protein degradation through the ubiquitin-proteasome pathway. Instead, Parkin represses Eg5 gene transcription by blocking c-Jun binding to the activator protein 1 site present in the Eg5 promoter. Our data further show that Parkin inactivates c-Jun NH2-terminal kinase (JNK), resulting in decreased phosphorylation of c-Jun. The inactivation of JNK is further mediated by multiple monoubiquitination of Hsp70. Importantly, both the ubiquitination of Hsp70 and the subsequent inactivation of the JNK-c-Jun pathway are crucial for Parkin to down-regulate Eg5 expression. These results thus uncover a novel function for Parkin in modulating the expression of Eg5 through the Hsp70-JNK-c-Jun signaling pathway.
Journal of Biological Chemistry 11/2008; 283(51):35783-8. · 4.65 Impact Factor
[show abstract][hide abstract] ABSTRACT: Several DNA- and microtubule-binding agents are used to manage hematologic malignancies in the clinic. However, drug resistance has been a challenge, perhaps due to a few surviving cancer stem cells. Toxicity is another major impediment to successful chemotherapy, leading to an impoverished quality of life. Here, we show that a semisynthetic nontoxic tubulin-binding agent, 9-bromonoscapine (EM011), effectively inhibits growth and regresses multidrug resistance-associated protein (MRP)-overexpressing teniposide-resistant T-cell lymphoma xenografts and prolongs longevity. As expected, teniposide treatment failed to regress teniposide-resistant xenografts, rather, treated mice suffered tremendous body weight loss. Mechanistically, EM011 displays significant antiproliferative activity, perturbs cell cycle progression by arresting mitosis, and induces apoptosis in teniposide-resistant lymphoblastoid T cells both in vitro and in vivo. EM011-induced apoptosis has a mitochondrially-mediated component, which was attenuated by pretreatment with cyclosporin A. We also observed alterations of apoptosis-regulatory molecules such as inactivation of Bcl2, translocation of BAX to the mitochondrial membrane, cytochrome c release, and activation of downstream apoptotic signaling. EM011 caused DNA degradation as evident by terminal deoxynucleotidyl transferase-mediated dUTP-biotin end labeling staining of the increased concentration of 3'-DNA ends. Furthermore, the apoptotic induction was caspase dependent as shown by cleavage of the caspase substrate, poly(ADP)ribose polymerase. In addition, EM011 treatment caused a suppression of natural survival pathways such as the phosphatidylinositol-3'-kinase/Akt signaling. These preclinical findings suggest that EM011 is an excellent candidate for clinical evaluation.
Cancer Research 04/2008; 68(5):1495-503. · 8.65 Impact Factor
[show abstract][hide abstract] ABSTRACT: Myelosuppression and associated immunosuppression are major problems in cancer chemotherapy. Thus, infection remains a significant source of morbidity and mortality during chemotherapy of cancer patients. Viral infections, particularly herpes simplex virus, varicella zoster virus, and cytomegalovirus, result either due to reactivation of latent viruses or new infections as sequelae of chemotherapy and debilitated cell-mediated immunity. Ultimately, the resolution of these infections can only be achieved after the control of malignancy and regaining the patient's ability to mount adequate immune responses. We show here that EM011, a tubulin-binding, nontoxic, orally available anticancer agent, does not alter absolute CD4(+), CD8(+), B220(+), and NK1.1(+) cell counts in immunocompetent mice. More importantly, EM011 treatment at tumor-suppressive dosages (300 mg/kg) does not suppress cell-mediated immune responses in mice experimentally challenged with acute lymphocytic choriomeningitis virus infection, in that mice mount robust virus-specific CD8(+) and CD4(+) T-cell immune responses while maintained on daily drug treatment. Thus, CD8(+) and CD4(+) T-cell expansion and acquisition of effector functions is not perturbed by EM011 treatment. These data provide compelling evidence to support the nonimmunosuppressive nature of EM011 therapy and provide strong impetus for combining chemotherapy with immunotherapy as a novel anticancer strategy.
Molecular Cancer Therapeutics 12/2007; 6(11):2891-9. · 5.60 Impact Factor
[show abstract][hide abstract] ABSTRACT: Noscapine, a naturally occurring antitussive phthalideisoquinoline alkaloid, is a tubulin-binding agent currently in Phase I/II clinical trials for anticancer therapy. Unlike currently available antimitotics such as taxanes and vincas, noscapine is water-soluble, well tolerated, and shows no detectable toxicity.
The goal was to develop a simple, sensitive, quantitative, selective, and less time-consuming high-performance liquid chromatography (HPLC) method for determination of noscapine and to study its pharmacokinetics in mice models.
Noscapine was extracted from mice plasma using the protein-precipitation method and detected using a reversed-phase C8 column with mobile phase consisting of 35% acetonitrile and 65% ammonium acetate buffer (pH 4.5) at 232 nm wavelength. Pharmacokinetic studies of noscapine were performed in mice following intravenous bolus at 10 mg/kg and oral administrations at 75, 150, and 300 mg/kg.
The standard curves for noscapine estimation were linear between 390 and 50,000 ng/ml (lower limit of quantification was 390 ng/ml) and the recovery was approximately 80%. Following 10 mg/kg intravenous dose, mean plasma concentrations of 7.88 microg/ml were achieved at 5 min in mice and declined with undetectable levels at 4 h. The mean total body clearance was 4.78 l/h. The mean volume of distribution (V (d)) was 5.05 l. Non-compartmental analysis yielded the mean area under the plasma concentration-time curve (AUC) for noscapine as 53.42, 64.08, and 198.35 h microg/ml reaching maximum plasma concentrations (C (max)) of 12.74, 23.24, and 46.73 microg/ml at a t (max) of 1.12, 1.50, and 0.46 h at the linearly increasing dose levels.
A rapid and simple HPLC/UV method for the quantification of noscapine in plasma has been developed to study pharmacokinetics of noscapine at tumor-suppressive doses in the mouse. Since orally available anticancer drugs are rare, therefore, noscapine, an innocuous agent, having a mean oral bioavailability of 31.5% over the studied dose range merits its further advancement in humans for anticancer therapy.
Cancer Chemotherapy and Pharmacology 12/2007; 60(6):831-9. · 2.80 Impact Factor
[show abstract][hide abstract] ABSTRACT: Hypoxia-induced multidrug resistance 1 (MDR1) gene expression is known to be mediated by c-Jun NH(2)-terminal kinase (JNK) activation. However, the molecular mechanisms underlying this action of JNK remain elusive. On the contrary, there has been increasing evidence for a negative correlation of JNK activity with MDR1 expression under normoxic conditions. Here, we present evidence that the JNK pathway represses MDR1 expression in normoxia and activates MDR1 expression in hypoxia. Our data show that JNK pathway-induced MDR1 repression in normoxia is mediated by increased c-Jun binding to activator protein 1 site, located in the MDR1 promoter, and requires the activity of histone deacetylase 5. In contrast, JNK pathway-induced MDR1 activation in hypoxia is independent of the activator protein 1 site. Rather, this action is dependent on increased hypoxia-inducible factor 1 (HIF1) binding to the hypoxia response element in the MDR1 promoter, which is promoted by the interaction of HIF1alpha with c-Jun in the nucleus and requires the activity of the p300/CBP (CREB-binding protein) coactivator.
Journal of Biological Chemistry 07/2007; 282(24):17581-6. · 4.65 Impact Factor