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1

Paclitaxel (Taxol) for the treatment of lymphoma.  

PubMed

Paclitaxel (Taxol) was recently tested in patients with relapsed and refractory lymphoma in two phase II clinical trials using two different infusion schedules. The first, reported from the NCI (USA), used a 96-hour intravenous continuous infusion schedule, and the second, from our group, used a 3-hour infusion. In the NCI trial, 29 evaluable patients were treated with 140 mg/m2 every three weeks, which achieved a 17% response rate (all PRs); while we treated 96 evaluable patients with 200 mg/m/ every three weeks, which achieved a 25% response rate (10 CRs and 14 PRs, 95% CI: 17%-35%). In our trial, patients with relapsed (not primary refractory) intermediate-grade lymphoma had a response rate of 50%, and those with relapsed low-grade lymphoma had a response rate of 31%. In a follow-up trial, 12 patients who failed to respond to 3-hour infusion of paclitaxel were crossed over to receive paclitaxel by 96-hour infusion. None of the 12 evaluable patients achieved a major clinical response. Similarly, of 25 patients treated with cyclosporine A and paclitaxel after failing therapy with single-agent paclitaxel, only one patient (4%) responded. We conclude that paclitaxel has a promising single-agent activity, most prominently in patients with relapsed intermediate-grade lymphoma. Paclitaxel-based combination programs are currently being evaluated in our institution. PMID:9187446

Younes, A; Ayoub, J P; Sarris, A; North, L; Pate, O; McLaughlin, P; Rodriguez, M A; Romaguera, J; Hagemeister, F; Bachier, C; Preti, A; Cabanillas, F

1997-01-01

2

Paclitaxel (Taxol)Induced Killing of Leishmania major in Murine Macrophages  

Microsoft Academic Search

Lpsn, but not Lpsd, macrophages by a nitric oxide (NOz)-dependent mechanism. In 1990, Ding and colleagues (3, 5) demonstrated that the antitumor agent paclitaxel (Taxol) induced in murine macro- phages secretion of tumor necrosis factor alpha (TNF-a) and involution of TNF receptors, two actions also elicited by gram- negative lipopolysaccharide (LPS). They also demonstrated that, like LPS, paclitaxel effects were

T. MARK DOHERTY; ALAN SHER; STEFANIE N. VOGEL

1998-01-01

3

Proliferation, migration and invasion of human glioma cells exposed to paclitaxel (Taxol) in vitro  

Microsoft Academic Search

Paclitaxel (Taxol), an anti-cancer drug derived from Taxus species, was tested for its anti-migrational, anti-invasive and anti-proliferative effect on two human glioma cell lines (GaMg and D-54Mg) grown as multicellular tumour spheroids. In addition, the direct effect of paclitaxel on glioma cells was studied using flow cytometry and scanning confocal microscopy. Both cell lines showed a dose-dependent growth and migratory

A-JA Terzis; F Thorsen; O Heese; T Visted; R Bjerkvig; O Dahl; H Arnold; G Gundersen

1997-01-01

4

In vitro synergy of paclitaxel (Taxol) and vinorelbine (navelbine) against human melanoma cell lines  

Microsoft Academic Search

Paclitaxel (PTXL) (Taxol), a taxane, and vinorelbine (VRB), a semisynthetic vinca alkaloid drug, have tubulin as their common intracellular target, but inhibit growth by binding to different sites. We evaluated in vitro the antiproliferative activity of these two drugs as single agents and in combination, against two human melanoma cell lines, G361 and StM111a. The SRB (sulphorhodamine B) assay was

A. Photiou; P. Shah; L. K. Leong; J. Moss; S. Retsas

1997-01-01

5

Mechanistic population pharmacokinetics of total and unbound paclitaxel for a new nanodroplet formulation versus Taxol in cancer patients  

Microsoft Academic Search

Purpose  Our objectives were (1) to compare the disposition and in vivo release of paclitaxel between a tocopherol-based Cremophor-free\\u000a formulation (Tocosol Paclitaxel®) and Cremophor® EL-formulated paclitaxel (Taxol®) in human subjects, and (2) to develop a mechanistic model for unbound and total paclitaxel pharmacokinetics.\\u000a \\u000a \\u000a \\u000a Methods  A total of 35 patients (average ± SD age: 59 ±13 years) with advanced non-hematological malignancies were studied in a randomized\\u000a two-way

Jürgen B. Bulitta; Ping Zhao; Robert D. Arnold; Dean R. Kessler; Richard Daifuku; James Pratt; Gabriel Luciano; Axel-R Hanauske; Hans Gelderblom; Ahmad Awada; William J. Jusko

2009-01-01

6

Medium chain triglyceride (MCT) rich, paclitaxel loaded self nanoemulsifying preconcentrate (PSNP): a safe and efficacious alternative to Taxol.  

PubMed

The current work was aimed to develop Medium Chain Triglyceride (MCT) rich self nanoemulsifying preconcentrate of paclitaxel (PTX) for parenteral delivery. Very high concentrations of Cremophor EL and ethanol in Taxol have rendered patients to severe side effects. Years of extensive research on development of cost effective and safer vehicle for PTX, have failed to provide a promising replacement for Taxol. MCT was selected as oil owing to its parenteral acceptability, high solubilization capacity and multiple therapeutic benefits in cancer cachexia. PTX precipitation kinetics and reported toxicity profile of Kolliphor HS15 has favored its selection for PTX Self Nanoemulsifying Preconcentrate (PSNP). Presence of 30% free PEG in Kolliphor HS15 (PEG-15-hydroxystearate) restricts its miscibility with MCT, imposing significant challenge in development of MCT rich self nanoemulsifying preconcentrate. Removal of PEG layer from oil-surfactant mixture facilitated the formulation of PSNP with 51% w/w MCT. PSNP exhibited better precipitation kinetic profile, higher PTX loading with negligible hemolysis and histamine release compared to Taxol. PSNP was bioequivalent to Taxol, though V(d) and MRT was significantly higher than Taxol. PSNP showed distinctly better profile in inhibiting tumor growth and maintaining body weight with significantly higher % survival. Thus, PSNP can be a safer vehicle with potential clinical benefits. PMID:24266255

Patel, Ketan; Patil, Anand; Mehta, Miten; Gota, Vikram; Vavia, Pradeep

2013-12-01

7

Marked enhancement in vivo of paclitaxel's (taxol's) tumor-regressing activity by ATP-depleting modulation.  

PubMed

Paclitaxel alone is active against the CD8F1 murine spontaneous mammary cancer, and when administered following an ATP-depleting combination of N-(phosphonacetyl)-L-aspartate (PALA) + 6-methylmercaptopurine riboside (MMPR) + 6-aminonicotinamide (6-AN) (PMA) produced significantly enhanced partial tumor regressions over that produced by either paclitaxel alone at the maximal tolerated dose (MTD), or by the PMA drug combination alone, against advanced, first passage spontaneous murine breast tumors. The anticancer activity of paclitaxel is due to enhancement and stabilization of microtubule polymerization. Pertinently, microtubule disassembly (an ATP-dependent process) is known to sharply decrease in the presence of ATP depletion. Thus, the dramatic therapeutic enhancement observed with paclitaxel in combination with PMA is in agreement with biochemical expectations, since PMA has been shown to deplete ATP in CD8F1 tumor cells. The augmented therapeutic results were obtained with approximately one-third the MTD of paclitaxel as a single agent and suggest the potential clinical benefit of more effective treatment with lesser amounts of drug. PMID:8913434

Martin, D S; Stolfi, R L; Colofiore, J R; Nord, L D

1996-08-01

8

Fatal poisoning with Taxus baccata: quantification of paclitaxel (taxol A), 10-deacetyltaxol, baccatin III, 10-deacetylbaccatin III, cephalomannine (taxol B), and 3,5-dimethoxyphenol in body fluids by liquid chromatography-tandem mass spectrometry.  

PubMed

This method development was to confirm the fatal ingestion of toxic yew plant material in postmortem samples (stomach content, urine, femoral blood, cardiac blood, bile, and brain tissue) collected from a 22-year-old man who committed suicide by ingesting yew leaves. The analytical method was based on a liquid-liquid extraction under alkaline conditions followed by LC-MS-MS analysis. Chromatographic separation was achieved by HPLC on a Kinetex C18 2.6u (100 × 3 mm) coupled to a QTRAP 5500 system. The method allows the simultaneous identification and quantification of the yew alkaloids taxoids paclitaxel (taxol A), 10-deacetyltaxol, baccatin III, 10-deacetylbaccatin III, cephalomannine (taxol B), and 3,5-dimethoxyphenol; the alkaloidal diterpenoids monoacetyltaxine, taxine B, monohydroxydiacetyltaxine, triacetyltaxine, and monohydroxytriacetyltaxine were also identified. The initial hypothesis of yew tree (Taxus baccata) poisoning was confirmed. The quantitative evaluation revealed taxoid concentrations ranging from 4.5 to 132 µg/L (stomach content), 1 to 200 µg/L (urine), <0.5 to 12 µg/L (cardiac blood), <0.5 to 7.3 µg/L (femoral blood), and 4.9 to 290 µg/L (bile). In brain tissue, none of these taxoids could be detected (<0.5 µg/L). In urine, after enzymatic hydrolysis, the concentration of 3,5-dimethoxyphenol (3,5-DMP) was 23,000 µg/L. The alkaloidal diterpenoids were found in all postmortem samples. The newly developed LC-MS-MS method enables the identification of alkaloidal and non-alkaloidal diterpenoids and 3,5-dimethoxyphenol in human body fluids and tissues for the confirmation of accidental or intentional poisonings with yew plant material. PMID:22290751

Grobosch, T; Schwarze, B; Stoecklein, D; Binscheck, T

2012-01-01

9

Comparative proteomic analysis of paclitaxel sensitive A549 lung adenocarcinoma cell line and its resistant counterpart A549Taxol  

Microsoft Academic Search

Purpose  Paclitaxel is used as the first-line chemotherapy for Non-Small Cell Lung Cancer (NSCLC), but acquired resistance becomes\\u000a a critical problem. Several mechanisms have been proposed in paclitaxel resistance, but they are not sufficient to exhaustively\\u000a explain this resistance emergence. To better investigate molecular resistance mechanisms, a comparative proteomic approach\\u000a was carried out to identify differentially expressed proteins between human lung

Qiang-ling Sun; Hui-fang Sha; Xiao-hua Yang; Guo-liang Bao; Jing Lu; Yin-yin Xie

2011-01-01

10

The cytotoxic activity of Taxol in primary cultures of tumour cells from patients is partly mediated by Cremophor EL.  

PubMed Central

In patient tumour samples the activity in vitro of Taxol corresponded fairly well to the known clinical activity and Taxol showed low cross-resistance to standard cytotoxic drugs. However, the Taxol solvent Cremophor EL--ethanol was considerably active alone, whereas paclitaxel formulated in ethanol was less active. Taxol thus seems to contain two components active against patient tumour cells in vitro.

Nygren, P.; Csoka, K.; Jonsson, B.; Fridborg, H.; Bergh, J.; Hagberg, H.; Glimelius, B.; Brodin, O.; Tholander, B.; Kreuger, A.

1995-01-01

11

Interaction of taxol with human serum albumin  

Microsoft Academic Search

Taxol (paclitaxel) is an anticancer drug, which interacts with microtuble proteins, in a manner that catalyzes their formation from tubulin and stabilizes the resulting structures (Nogales et al., Nature 375 (1995) 424–427). This study was designed to examine the interaction of taxol with human serum albumin (HSA) in aqueous solution at physiological pH with drug concentrations of 0.0001–0.1 mM, and

M. Purcell; J. F. Neault; H. A. Tajmir-Riahi

2000-01-01

12

Enhanced Oral Paclitaxel Bioavailability After Administration of Paclitaxel-Loaded Lipid Nanocapsules  

Microsoft Academic Search

\\u000a Purpose  The aim of this study was to evaluate the pharmacokinetics of paclitaxel-loaded lipid nanocapsules (LNC) in rats to assess\\u000a the intrinsic effect of the dosage form on the improvement of paclitaxel oral exposure.\\u000a \\u000a \\u000a \\u000a Methods  Paclitaxel-loaded LNC were prepared and characterized in terms of size distribution, drug payload, and the kinetics of paclitaxel\\u000a crystallization. Taxol, Taxol with verapamil, or paclitaxel-loaded LNC were

Sandra Peltier; Jean-Michel Oger; Frédéric Lagarce; William Couet; Jean-Pierre Benoît

2006-01-01

13

Paclitaxel Versus Docetaxel for Early Breast Cancer  

Cancer.gov

Weekly treatment with the drug paclitaxel (Taxol®) in addition to standard chemotherapy proved most effective in extending overall survival among women with early-stage breast cancer, according to the April 17, 2008, New England Journal of Medicine.

14

Design and synthesis of a combinatorial chemistry library of 7-acyl, 10-acyl, and 7,10-diacyl analogues of paclitaxel (taxol) using solid phase synthesis.  

PubMed

A series of 10-acyl and 7,10-diacyl paclitaxel analogues (7a-7e and 9a-9u) have been synthesized using a solid phase combinatorial chemistry approach, and a second series of 7-acyl-10-deacetylpaclitaxel analogues have been prepared by conventional chemistry. In the first series, 10-deacetylpaclitaxel (4) was linked through its 2'-hydroxyl group using 1% polystyrene-divinyl benzene resin functionalized with butyldiethylsilane linker (PS-DES) and then acylated at the C-10 hydroxyl group with various anhydrides and dialkyl dicarbonates in the presence of CeCl(3). The resin-bound C-10 acylated paclitaxel derivatives (6a-6e) were then treated with various carboxylic acids in the presence of 1,3-diisopropylcarbodiimide in toluene to provide polymer-supported 7,10-diacylpaclitaxels (8a-8u). These 7-acyl- and 7,10-diacylpaclitaxels (6a-6e and 8a-8u) were cleaved from the resin to give the 24 paclitaxel analogues 7a-7e and 9a-9u. Nine 7-acyl-10-deacetylpaclitaxel analogues were also prepared by conventional chemistry. Methodology to determine the tubulin-assembly activity of compounds prepared in small quantities by a combinatorial approach has been developed, and four analogues with improved tubulin-assembly activity as compared with paclitaxel were found, together with two analogues with improved cytotoxicity. PMID:12193017

Jagtap, Prakash G; Baloglu, Erkan; Barron, Donna M; Bane, Susan; Kingston, David G I

2002-08-01

15

Phase I Study of Paclitaxel (Taxol) and Pegylated Liposomal Doxorubicin (Caelyx) Administered Every 2 Weeks in Patients with Advanced Solid Tumors  

Microsoft Academic Search

Objectives: Paclitaxel and doxorubicin are among the most active chemotherapeutic agents in various types of tumors. Pegylated liposomal doxorubicin (Caelyx) has a more favorable pharmacokinetic and toxicity profile than the free drug. We conducted a phase I study to determine the maximum tolerated doses (MTD) and the dose limiting toxicities (DLT) of the combination administered every 2 weeks in patients

D. Mavroudis; Ch. Kouroussis; S. Kakolyris; S. Agelaki; K. Kalbakis; N. Androulakis; J. Souglakos; G. Samonis; V. Georgoulias

2002-01-01

16

Fluorescence imaging analysis of taxol-induced ASTC-a-1 cell death with cell swelling and cytoplasmic vacuolization  

Microsoft Academic Search

Taxol (Paclitaxel), an isolated component from the bark of the Pacific yew Taxus brevifolia, exhibits a broad spectrum of clinical activity against human cancers. Taxol can promote microtubule (MT) assembly, inhibit depolymerization, and change MT dynamics, resulting in disruption of the normal reorganization of the microtubule network required for mitosis and cell proliferation. However, the molecular mechanism of taxol-induced cell

Tong-sheng Chen; Lei Sun; Longxiang Wang; Huiying Wang

2008-01-01

17

Pharmacokinetic modeling of paclitaxel encapsulation in Cremophor EL micelles  

Microsoft Academic Search

Nonlinear disposition of paclitaxel (Taxol) in cancer patients has been described in several studies, but the underlying mechanism is still a matter of speculation. Previously, we have shown in vitro that the paclitaxel formulation vehicle, Cremophor EL (CrEL), alters the blood distribution of paclitaxel as a result of entrapment of the compound in circulating CrEL micelles, thereby reducing the free

Lia van Zuylen; Mats O. Karlsson; Jaap Verweij; Eric Brouwer; Peter de Bruijn; Kees Nooter; Gerrit Stoter; Alex Sparreboom

2001-01-01

18

Ethosuximide reverses paclitaxel- and vincristine-induced painful peripheral neuropathy  

Microsoft Academic Search

Paclitaxel (Taxol®) is one of the most effective and frequently used chemotherapeutics for the treatment of solid tumours. However, paclitaxel produces peripheral neurotoxicity with patients reporting sensory abnormalities and neuropathic pain during and often persisting after paclitaxel therapy. The mechanisms underlying this dose-limiting side effect are currently unknown and there are no validated drugs for its prevention or control. Male

Sarah J. L Flatters; Gary J Bennett

2004-01-01

19

Interaction of taxol with human serum albumin.  

PubMed

Taxol (paclitaxel) is an anticancer drug, which interacts with microtuble proteins, in a manner that catalyzes their formation from tubulin and stabilizes the resulting structures (Nogales et al., Nature 375 (1995) 424-427). This study was designed to examine the interaction of taxol with human serum albumin (HSA) in aqueous solution at physiological pH with drug concentrations of 0.0001-0.1 mM, and HSA (fatty acid free) concentration of 2% w/v. Gel electrophoresis, absorption spectra and Fourier transform infrared (FTIR) spectroscopy with self-deconvolution and second-derivative resolution enhancement were used to determine the drug binding mode, binding constant and the protein secondary structure in the presence of taxol in aqueous solution. Spectroscopic evidence showed that taxol-protein interaction results into two types of drug-HSA complexes with overall binding constant of K=1.43 x 10(4) M(-1). The molar ratios of complexes were of taxol/HSA 30/1 (30 mM taxol) and 90/1 (90 mM taxol) with the complex ratios of 1.9 and 3.4 drug molecules per HSA molecule, respectively. The taxol binding results in major protein secondary structural changes from that of the alpha-helix 55 to 45% and beta-sheet 22 to 26%, beta-anti 12 to 15% and turn 11 to 16%, in the taxol-HSA complexes. The observed spectral changes indicate a partial unfolding of the protein structure, in the presence of taxol in aqueous solution. PMID:10719175

Purcell, M; Neault, J F; Tajmir-Riahi, H A

2000-03-16

20

Transcript: Taxol  

Cancer.gov

Michael Grever, M.D., Former Associate Director, DTP: The story of Taxol is probably the National Cancer Institute in its finest hour. It was actually through the National Cancer Institute that this Natural Products work was supported, and Dr. Monroe

21

Formation of complement-activating particles in aqueous solutions of Taxol: possible role in hypersensitivity reactions  

Microsoft Academic Search

We reported earlier that the anticancer drug paclitaxel (Taxol) activated the complement (C) system in human serum in vitro, raising the possibility that C activation might play a role in the ill-understood hypersensitivity reactions (HSRs) to this drug [J. Natl. Cancer Inst. 90 (1998) 300]. In pursuing the mechanism of C activation by Taxol, the present study provided evidence that

Janos Szebeni; Carl R. Alving; Sandor Savay; Yechezkel Barenholz; Aba Priev; Dganit Danino; Yeshayahu Talmon

2001-01-01

22

High sensitivity ELISA determination of taxol in various human biological fluids  

Microsoft Academic Search

Taxol (paclitaxel)-the natural product isolated from Pacific yew (Taxus brevifolia) is a novel agent with high activity in the treatment of patients with several malignant tumors including those resistant to other cytotoxic drugs. The therapeutic index of this promising anticancer drug could be further increased by the exploration of its pharmacokinetic–pharmacodynamic relationship in cancer patients. Since taxol is highly protein

Stan R Svojanovsky; Kamal L Egodage; Jun Wu; Milan Slavik; George S Wilson

1999-01-01

23

Stabilized micelles as delivery vehicles for paclitaxel.  

PubMed

Paclitaxel is an antineoplastic drug used against a variety of tumors, but its low aqueous solubility and active removal caused by P-glycoprotein in the intestinal cells hinder its oral administration. In our study, new type of stabilized Pluronic micelles were developed and evaluated as carriers for paclitaxel delivery via oral or intravenous route. The pre-stabilized micelles were loaded with paclitaxel by simple solvent/evaporation technique achieving high encapsulation efficiency of approximately 70%. Gastrointestinal transit of the developed micelles was evaluated by oral administration of rhodamine-labeled micelles in rats. Our results showed prolonged gastrointestinal residence of the marker encapsulated into micelles, compared to a solution containing free marker. Further, the oral administration of micelles in mice showed high area under curve of micellar paclitaxel (similar to the area of i.v. Taxol(®)), longer mean residence time (9-times longer than i.v. Taxol(®)) and high distribution volume (2-fold higher than i.v. Taxol(®)) indicating an efficient oral absorption of paclitaxel delivered by micelles. Intravenous administration of micelles also showed a significant improvement of pharmacokinetic parameters of micellar paclitaxel vs. Taxol(®), in particular higher area under curve (1.2-fold), 5-times longer mean residence time and lower clearance, indicating longer systemic circulation of the micelles. PMID:22721848

Yoncheva, Krassimira; Calleja, Patricia; Agüeros, Maite; Petrov, Petar; Miladinova, Ivanka; Tsvetanov, Christo; Irache, Juan M

2012-10-15

24

Adding Taxol to Initial Chemotherapy May Be New Option When Breast Cancer Has Spread to Lymph Nodes  

Cancer.gov

Early findings from a large, multicenter trial suggest that the drug Taxol (paclitaxel), in combination with other standard chemotherapy agents, may have a small but significant benefit for breast cancer patients whose disease has spread to nearby lymph nodes.

25

Design and synthesis of de novo cytotoxic alkaloids by mimicking the bioactive conformation of paclitaxel  

PubMed Central

Novel paclitaxel-mimicking alkaloids were designed and synthesized based on a bioactive conformation of paclitaxel, i.e., REDOR-Taxol. The alkaloid 2 bearing a 5-7-6 tricyclic scaffold mimics REDOR-Taxol best among the compounds designed and was found to be the most potent compound against several drug-sensitive and drug-resistant human cancer cell lines. MD simulation study on the paclitaxel mimics 1 and 2 as well as REDOR-Taxol bound to the 1JFF tubulin structure was quite informative to evaluate the level of mimicking. The MD simulation study clearly distinguishes the 5-6-6 and 5-7-6 tricyclic scaffolds, and also shows substantial difference in the conformational stability of the tubulin-bound structures between 2 and REDOR-Taxol. The latter may account for the large difference in potency, and provides critical information for possible improvement in the future design of paclitaxel mimics.

Sun, Liang; Veith, Jean M.; Pera, Paula; Bernacki, Ralph J.; Ojima, Iwao

2010-01-01

26

Quantitative determination of total and unbound paclitaxel in human plasma following Abraxane treatment  

Microsoft Academic Search

A simple, rapid liquid chromatography\\/tandem mass spectrometric (LC–MS\\/MS) assay was developed and validated for the quantification of both unbound and total paclitaxel in plasma following treatment with Abraxane (ABI-007) or Taxol. Accurate and reproducible analysis of ABI-007, an albumin nanoparticle formulation of paclitaxel could not be achieved using previously published methodology designed for Taxol. The final validated method involved protein

Erin R. Gardner; William Dahut; William D. Figg

2008-01-01

27

Cytotoxic activity of a new paclitaxel formulation, Pacliex, in vitro and in vivo  

Microsoft Academic Search

Background The paclitaxel formulation, Taxol (Bristol-Myers Squibb), is one of the most effective anticancer agents used today. However; it is associated with serious side effects believed to be caused by the Cremophor EL used for its formulation. Aim To evaluate the cytotoxic activity of a new paclitaxel formulation, Pacliex (developed by Oasmia Pharmaceutical, Uppsala, Sweden), a mixed micelles preparation in

Saadia Hassan; Sumeer Dhar; Marie Sandström; Dzmitry Arsenau; Marina Budnikova; Igor Lokot; Nikolai Lobanov; Mats O. Karlsson; Rolf Larsson; Elin Lindhagen

2005-01-01

28

Pharmaceutical Nanotechnology Enhanced solubility and stability of PEGylated liposomal paclitaxel: In vitro and in vivo evaluation  

Microsoft Academic Search

An improved PEGylated liposomal formulation of paclitaxel has been developed with the purpose of improving the solubility of paclitaxel as well as the physicochemical stability of liposome in comparison to the current Taxol® formulation. The use of 3% (v\\/v) Tween 80 in the hydration media was able to increase the solubility of drug. The addition of sucrose as a lyoprotectant

Tao Yang; Fu-De Cui; Min-Koo Choi; Jei-Won Cho; Suk-Jae Chung; Chang-Koo Shim; Dae-Duk Kim

29

Preparation, characterization and properties in vitro and in vivo of a paclitaxel–albumin conjugate  

Microsoft Academic Search

Paclitaxel (taxol) is in routine clinical use for treatment of a variety of cancers. Because of its low aqueous solubility, it requires Cremophor EL (polyethoxylated castor oil) and ethanol as a vehicle (Diluent 12). These agents cause severe allergic reactions upon intravenous administration. In this study paclitaxel was covalently attached to human serum albumin. The 2?-hydroxyl group of the drug

Franco Dosio; Paola Brusa; Paola Crosasso; Silvia Arpicco; Luigi Cattel

1997-01-01

30

Peripheral Neuropathy Induced by Paclitaxel: Recent Insights and Future Perspectives  

PubMed Central

Paclitaxel is an antineoplastic agent derived from the bark of the western yew, Taxus brevifolia, with a broad spectrum of activity. Because paclitaxel promotes microtubule assembly, neurotoxicity is one of its side effects. Clinical use of paclitaxel has led to peripheral neuropathy and this has been demonstrated to be dependent upon the dose administered, the duration of the infusion, and the schedule of administration. Vehicles in the drug formulation, for example Cremophor in Taxol®, have been investigated for their potential to induce peripheral neuropathy. A variety of neuroprotective agents have been tested in animal and clinical studies to prevent paclitaxel neurotoxicity. Recently, novel paclitaxel formulations have been developed to minimize toxicities. This review focuses on recent advances in the etiology of paclitaxel-mediated peripheral neurotoxicity, and discusses current and ongoing strategies for amelioration of this side effect.

Scripture, Charity D; Figg, William D; Sparreboom, Alex

2006-01-01

31

Characterization and activity of sonochemically-prepared BSA microspheres containing Taxol – An anticancer drug  

Microsoft Academic Search

Proteinaceous microspheres of BSA (Bovine Serum Albumin) containing an anticancer drug, Taxol (paclitaxel) were fabricated using a sonochemical procedure and then assayed for chemical and biological activity. The sonochemical reaction did not compromise the drug, which became encapsulated in the BSA microspheres. The amount of the anticancer drug in the microspheres was determined by HPLC. Anticancer activity of the proteinaceous

Olga Grinberg; Michal Hayun; Benjamin Sredni; Aharon Gedanken

2007-01-01

32

Application of lipid as emulsifier in the solvent evaporation technique in fabrication of polymeric nanospheres for controlled release of Taxol  

Microsoft Academic Search

This study was intended to examine the potential of application of 1,2-dipalmitoylphosphatidyl-choline (DPPC) as an emulsifier in the solvent evaporation technique, which is one of the most widely used methods to prepare polymeric microspheres and nanospheres for controlled release of an effective anticancer drug Paclitaxel (Taxol(R)). The poly(D,L-lactic-co-glycolic acid) (PLGA, 75\\/25) nanospheres loaded with Taxol were prepared by the solvent

Guo-feng Huangl; Si-Shen Feng

2000-01-01

33

Isolation of anticancer drug TAXOL from Pestalotiopsis breviseta with apoptosis and B-Cell lymphoma protein docking studies  

PubMed Central

Background: Extraction and investigation of TAXOL from Pestalotiopsis breviseta (Sacc.) using protein docking, which is a computational technique that samples conformations of small molecules in protein-binding sites. Scoring functions are used to assess which of these conformations best complements the protein binding site and active site prediction. Materials and Methods: Coelomycetous fungi P. breviseta (Sacc.) Steyaert was screened for the production of TAXOL, an anticancer drug. Results: TAXOL production was confirmed by the following methods: Ultraviolet (UV) spectroscopic analysis, Infrared analysis, High performance liquid chromatography analysis (HPLC), and Liquid chromatography mass spectrum (LC-MASS). TAXOL produced by the fungi was compared with authentic TAXOL, and protein docking studies were performed. Conclusion: The BCL2 protein of human origin showed a higher affinity toward the compound paclitaxel. It has the binding energy value of ?13.0061 (KJ/Mol) with four hydrogen bonds.

Kathiravan, G.; Sureban, Sripathi M.; Sree, Harsha N.; Bhuvaneshwari, V.; Kramony, Evelin

2012-01-01

34

Preliminary analysis of a phase II study of Paclitaxel and CHART in locally advanced non-small cell lung cancer  

Microsoft Academic Search

Paclitaxel (Taxol®; Bristol-Myers Squibb) is one of the most active single agents for non-small cell lung cancer (NSCLC), and ideal in combination with radiation therapy. We designed a phase II study to determine the efficacy and toxicity of continuous hyperfractionated accelerated radiotherapy (CHART) and concurrent weekly Paclitaxel (T) in good performance status patients with unresectable stage III A and B

Ethem Nezih Oral; Sevil Bavbek; Ahmet Kizir; Nuri Tenececi; Adnan Yöney; Esra Kaytan; Erkan Topuz

1999-01-01

35

High sensitivity ELISA determination of taxol in various human biological fluids.  

PubMed

Taxol (paclitaxel)--the natural product isolated from Pacific yew (Taxus brevifolia)--is a novel agent with high activity in the treatment of patients with several malignant tumors including those resistant to other cytotoxic drugs. The therapeutic index of this promising anticancer drug could be further increased by the exploration of its pharmacokinetic pharmacodynamic relationship in cancer patients. Since taxol is highly protein bound, a very specific and highly sensitive analytical method is required in order to determine free, protein unbound and biologically active taxol species in human physiological fluids: plasma; plasma ultrafiltrate; and salivary fluids. In order to accomplish this, a new indirect competitive enzyme-linked immunosorbent assay (ELISA), for quantitating such a low bioactive taxol concentration level, has been developed in our laboratories. This method uses taxol competitive inhibition of mouse anti-taxol antibodies binding to the solid phase coated antigen 7-succinyltaxol-bovine serum albumin. This indicates recognition of the active taxol in the solution phase, where a diluted horseradish peroxidase labeled goat anti-mouse enzyme conjugate is used. While employing this technique, after systematic optimization of the experimental conditions, we are able to detect the anticipated taxol in plasma ultrafiltrate and salivary fluids at the concentration level of subpicogram per milliliter. The working range of the assay is approximately five orders in magnitude, i.e. from pg ml(-1) to 100 ng ml(-1). The clinical part of this study verified the working range of the ELISA method using samples of physiological fluids from a cancer patient treated with 3 h intravenous (i.v.) infusion of this drug. Our results of taxol determination in plasma, plasma ultrafiltrate and saliva demonstrate the applicability of the newly developed ELISA method for further pharmacokinetic studies of free, biologically active taxol species in cancer patients. PMID:10701971

Svojanovsky, S R; Egodage, K L; Wu, J; Slavik, M; Wilson, G S

1999-07-01

36

Paclitaxel ameliorates fibrosis in hepatic stellate cells via inhibition of TGF-?/Smad activity  

PubMed Central

AIM: To investigated if paclitaxel can attenuate hepatic fibrosis in rat hepatic stellate cells (RHSCs). METHODS: RHSCs were cultured in vitro and randomly assigned to four groups: normal control group (treated only with Dulbecco’s Modified Eagle’s Medium), Taxol group (200 nmol/L paclitaxel was added to the cell culture), transforming growth factor (TGF)-? group (5 ng/mL recombinant human TGF-?1 was added to the cell culture), and TGF-? + Taxol group. TGF-? signaling cascade and status of various extracellular matrix proteins were evaluated by real time reverse transcriptase polymerase chain reaction and Western blotting. RESULTS: The paclitaxel treatment markedly suppressed Smad2/3 phosphorylation. This was associated with attenuated expression of collagen I and III and fibronectin in RHSCs. CONCLUSION: These data indicate that 200 nmol/L paclitaxel ameliorates hepatic fibrosis via modulating TGF-? signaling, and that paclitaxel may have some therapeutic value in humans with hepatic fibrosis.

Zhou, Jun; Zhong, De-Wu; Wang, Qun-Wei; Miao, Xiong-Ying; Xu, Xun-Di

2010-01-01

37

Induction of cytochrome P4503A by taxol in primary cultures of human hepatocytes.  

PubMed

In primary cultures of human hepatocytes, paclitaxel (Taxol), at pharmacological concentrations, was demonstrated to induce immunoreactive cytochrome P4503A (CYP3A). The magnitude of the inductive response of the hepatocytes to Taxol varied in five separate cultures. In general, exposure to increasing concentrations of Taxol (0.2 to 10 microM) resulted in increases in immunoreactive CYP3A. In four of the cultures, treatment of hepatocytes with the lowest concentration of Taxol tested (0.2 microM) resulted in approximately two-fold increases in CYP3A. In the other culture, however, a six-fold increase in CYP3A was observed at 0.2 microM. Taxol was almost as effective as rifampicin in inducing CYP3A in two of the cultures, but less effective than rifampicin in two other cultures. CYP3A4 mRNA was increased by Taxol. Increases in CYP3A4 mRNA correlated with increases in the levels of immunoreactive CYP3A. These results demonstrate that Taxol is a potent inducer of CYP3A in human hepatocytes. The clinical significance of these findings is discussed. PMID:9675018

Kostrubsky, V E; Lewis, L D; Strom, S C; Wood, S G; Schuetz, E G; Schuetz, J D; Sinclair, P R; Wrighton, S A; Sinclair, J F

1998-07-15

38

Paclitaxel Injection  

MedlinePLUS

Paclitaxel injection manufactured with human albumin is used to treat breast cancer that has not improved or that has come back after ... doctor and pharmacist if you are allergic to paclitaxel, any other ... polyoxyethylated castor oil, or medications that contain polyoxyethylated ...

39

Paclitaxel-HSA interaction. Binding sites on HSA molecule.  

PubMed

Paclitaxel (trade name Taxol) is one of the world's most effective anticancer drugs. It is used to treat several cancers including tumours of the breast, ovary and lung. In the present work the interaction of paclitaxel with human serum albumin (HSA) in aqueous solution at physiological pH has been investigated through CD, fluorescence spectroscopy and by the antibody precipitate test. Binding of paclitaxel to albumin impact on protein structure and it influences considerably albumin binding of other molecules like warfarin, heme or bilirubin. The paclitaxel-HSA interaction causes the conformational changes with the loss of helical stability of protein and local perturbation in the domain IIA binding pocket. The relative fluorescence intensity of the paclitaxel-bound HSA decreased, suggesting that perturbation around the Trp 214 residue took place. This was confirmed by the destabilization of the warfarin binding site, which includes Trp 214, and high affinity bilirubin binding site located in subdomain IIA. PMID:15158795

Trynda-Lemiesz, Lilianna

2004-06-15

40

Taxol alleviates 2-methoxyestradiol-induced endothelial permeability  

PubMed Central

We have previously shown that the anti-cancer agent 2-methoxyestradiol (2ME) induces hyperpermeability across endothelial monolayers. Here, we show that both microtubule disruptor, 2ME, and microtubule stabilizer, paclitaxel (taxol), increase vascular lung permeability in vitro and in vivo. Simultaneous application of 2ME and taxol alleviates 2ME-induced endothelial barrier dysfunction, which is evident by the decreased Evans Blue Dye accumulation in lung tissue and increased transendothelial resistance across monolayers. 2ME significantly increases the level of p38 and MLC phosphorylation in both endothelial monolayers and murine lungs; this increase is suppressed in the presence of taxol. Taxol treatment leads to an immediate and sustained increase in tubulin acetylation in human pulmonary artery endothelial cells (HPAEC). Surprisingly, 2ME treatment also increases tubulin acetylation; however, the on-set of this process is delayed and co-insides with the stage of a partial barrier restoration in HPAEC monolayer. Inhibition of histone deacetylase 6 (HDAC6) with tubacin increases tubulin acetylation level, suppresses 2ME-induced HSP27 and MLC phosphorylation, and decreases 2ME-induced barrier dysfunction, suggesting barrier-protective and/or barrier-restorative role for tubulin acetylation in vascular endothelium.

Gorshkov, Boris A.; Zemskova, Marina A.; Verin, Alexander D.; Bogatcheva, Natalia V.

2011-01-01

41

Weekly paclitaxel as first-line chemotherapy for elderly patients with metastatic breast cancer. A multicentre phase II trial  

Microsoft Academic Search

Paclitaxel is a cytotoxic agent with proven antitumour activity in metastatic breast cancer. Weekly administration of paclitaxel has demonstrated sustained efficacy together with a more favourable toxicity profile (e.g. less myelotoxicity) than the 3-weekly administration. This study evaluates the activity and toxicity of weekly paclitaxel (Taxol®) as first-line chemotherapy in elderly patients (>70 years of age) with hormone-refractory metastatic breast

A. J ten Tije; C. H Smorenburg; C Seynaeve; A Sparreboom; K. L. C Schothorst; L. G. M Kerkhofs; L. G. P. M van Reisen; G Stoter; M Bontenbal; J Verweij

2004-01-01

42

Abnormal muscle afferent function in a model of Taxol chemotherapy-induced painful neuropathy  

PubMed Central

Despite muscle pain being a well-described symptom in patients with diverse forms of peripheral neuropathy, the role of neuropathic mechanisms in muscle pain have received remarkably little attention. We have recently demonstrated in a well-established model of chemotherapy-induced painful neuropathy (CIPN) that the anti-tumor drug paclitaxel (Taxol) produces mechanical hyperalgesia in skeletal muscle, of similar time course to and with shared mechanism with cutaneous symptoms. In the present study, we evaluated muscle afferent neuron function in this rat model of CIPN. The mechanical threshold of muscle afferents in rats exposed to paclitaxel was not significantly different from the mechanical threshold of muscle afferents in control animals (P = 0.07). However, paclitaxel did produce a marked increase in the number of action potentials elicited by prolonged suprathreshold fixed intensity mechanical stimulation and a marked increase in the conduction velocity. In addition, the interspike interval (ISI) analysis (to evaluate the temporal characteristics of the response of afferents to sustained mechanical stimulation) showed a significant difference in rats treated with paclitaxel; there was a significantly greater ISI percentage of paclitaxel-treated muscle afferents with 0.01- and 0.02-s ISI. In contrast, an analysis of variability of neuronal firing over time (CV2 analysis) showed no effect of paclitaxel administration. These effects of paclitaxel on muscle afferent function contrast with the previously reported effects of paclitaxel on the function of cutaneous nociceptors.

Chen, Xiaojie; Green, Paul G.

2011-01-01

43

High affinity binding of paclitaxel to human serum albumin.  

PubMed

Paclitaxel, a very potent antitumor agent is a hydrophobic molecule with low aqueous solubility. Its currently used formula (Taxol) contains the drug in a 1 : 1 (v/v) mixture of ethanol and Cremophor EL. To minimize vehicle-related toxicity, we developed a novel, water-soluble formulation in which paclitaxel is bound noncovalently to human serum albumin. For this purpose, studies of the paclitaxel-albumin binding equilibrium were performed. Paclitaxel dissolved in ethanol was added to the aqueous solution of human serum albumin. Precipitated paclitaxel was removed and unbound drug was separated by ultrafiltration. Paclitaxel concentration was measured by RP-HPLC. Binding data were evaluated based both on the Scatchard plot and the general binding equation describing binding equilibria with the stepwise stoichiometric binding constants. The Scatchard plot was found to be curvilinear with a slight positive slope of the final part. Parameters of high affinity specific binding were determined from the initial part of the curve (nsp = 1.3 and Ksp = 1.7 x 10(6) M(-1)). Stoichiometric binding constants were estimated by fitting the general binding equation to the experimental data (K1 = 2.4 x 10(6) M(-1) and K2 = 1.0 x 10(5) M(-1)). Saturation of the protein with paclitaxel, similarly to other ligands of albumin, could not be reached. The greatest observed value of r (number of paclitaxel molecules bound to one albumin molecule) was 6.6. PMID:11277943

Paál, K; Müller, J; Hegedûs, L

2001-04-01

44

Taxol on the surface of leaves and inside the needles of three species and two varieties of Taxus.  

PubMed

Leaves of three outside-growing Taxus species (Taxus baccata L.; T. baccava var. elegantissima; T cuspidata Sieb, et Zucc; T. media var. Hatfieldii; T media var. Hickii) and two varieties contained 26-890 ?g/g of taxol (paclitaxel®), thus are substantial renewable resources for obtaining this drug. Taxol® was deposited on the surface of these needles in 0.1-1.29 ?g/g which was removed with brief dipping in hot water amounting up to 0.58% of total concentration. Two other taxanes were identified (7-epi-10-deacetyltaxol; cephalomannine) but still many await identification. Thus, renewable resources of taxol were found both within and on the leaf surface of different Taxus species. The highest taxol concentrations were found to be in the T. media hybrids, higher than in the case of both original species. PMID:23195085

Zobel, A M; Furmanowa, M; Glowniak, K; Cragg, C

1996-11-01

45

AURORA-A amplification overrides the mitotic spindle assembly checkpoint, inducing resistance to Taxol  

Microsoft Academic Search

The serine-threonine kinase gene AURORA-A is commonly amplified in epithelial malignancies. Here we show that elevated Aurora-A expression at levels that reflect cancer-associated gene amplification overrides the checkpoint mechanism that monitors mitotic spindle assembly, inducing resistance to the chemotherapeutic agent paclitaxel (Taxol). Cells overexpressing Aurora-A inappropriately enter anaphase despite defective spindle formation, and the persistence of Mad2 at the kinetochores,

Shubha Anand; Sue Penrhyn-Lowe; Ashok R Venkitaraman

2003-01-01

46

Divergent effect of taxol on proliferation, apoptosis and nitric oxide production in MHH225 CD34 positive and U937 CD34 negative human leukaemia cells  

Microsoft Academic Search

Paclitaxel (Taxol) has been shown to be clinically effective in treatment of patients with breast and ovarian cancer. It has also shown promising results in various other solid tumours. Paclitaxel has induced apoptosis in the G2\\/M phase of the cell cycle in both HL-60 and U937 human leukaemia cells. A recent study has shown a dose-dependent cytotoxicity for both taxanes:

O Al-alami; J Sammons; J. H Martin; H. T Hassan

1998-01-01

47

Diversity of endophytic fungi and screening of fungal paclitaxel producer from Anglojap yew, Taxus x media  

PubMed Central

Background Endophytic fungi represent underexplored resource of novel lead compounds and have a capacity to produce diverse class of plant secondary metabolites. Here we investigated endophytic fungi diversity and screening of paclitaxel-producing fungi from Taxus x media. Results Eighty-one endophytic fungi isolated from T. media were grouped into 8 genera based on the morphological and molecular identification. Guignardia and Colletotrichum were the dominant genera, whereas the remaining genera were infrequent groups. The genera Glomerella and Gibberella were first reported in Taxus. Three representative species of the distinct genera gave positive hits by molecular marker screening and were capable of producing taxol which were validated by HPLC-MS. Among these 3 taxol-producing fungi, the highest yield of taxol was 720 ng/l by Guignardia mangiferae HAA11 compared with those of Fusarium proliferatum HBA29 (240 ng/l) and Colletotrichum gloeosporioides TA67 (120 ng/l). This is the first report of taxol producer from Guignardia. Moreover, the lower similarities of ts and bapt between microbial and plant origin suggested that fungal taxol biosynthetic cluster might be repeatedly invented during evolution, nor horizontal gene transfer from Taxus species. Conclusions Taxol-producing endophytic fungi could be a fascinating reservoir to generate taxol-related drug lead and to elucidate the remained 5 unknown genes or the potential regulation mechanism in the taxol biosynthesis pathway.

2013-01-01

48

Lithium attenuates peripheral neuropathy induced by paclitaxel in rats.  

PubMed

As a cancer chemotherapeutic agent, paclitaxel (Taxol® ) causes dose-related peripheral neuropathy in human beings. The mechanisms underlying this toxicity are currently unknown, and there are no validated treatments for its prevention or control. To assess whether lithium as a pre-treatment and at subtherapeutic dose could prevent the peripheral neuropathy produced by it, rats were treated with paclitaxel (2?mg/kg i.p. every other day for a total of 16 times) and/or lithium chloride (300?mg/l) via water supply. General toxicity and body-weight were measured regularly during the experiment. To evaluate the sensory and motor neuropathy hot-plate, open-field test and nerve conduction velocity were used. In rats treated with only paclitaxel, there was behavioural, electrophysiological and histological evidence of a mixed sensorimotor neuropathy after 16 injections. Lithium robustly reduced the rate of mortality and general toxicity. Paclitaxel-induced sensorimotor neuropathy was significantly improved as indicated by changes in hotplate latency, total distance moved and a significant increase in sciatic, sural and tail sensory or motor nerve conduction velocity. The same results were observed in histopathological examinations; however, dorsal root ganglion neurons did not significantly change in the paclitaxel-treated groups. These results suggest that lithium, at subtherapeutic doses, can prevent both motor and sensory components of paclitaxel neuropathy in rats. Thus, lithium at these doses, as an inexpensive and relatively safe salt, may be useful clinically in preventing the neuropathy induced by paclitaxel treatment. PMID:21917116

Pourmohammadi, Nasir; Alimoradi, Houman; Mehr, Shahram Ejtemaei; Hassanzadeh, Gholamreza; Hadian, Mohammad Reza; Sharifzadeh, Mohammad; Bakhtiarian, Azam; Dehpour, Ahmad Reza

2012-03-01

49

[Antigenicity study of paclitaxel].  

PubMed

The antigenic property of paclitaxel was examined using its protein mixtures (paclitaxel + OVA, paclitaxel + GSA, paclitaxel + RSA) in guinea pigs and mice in comparison with ovalbumin (OVA) and the protein conjugate of 4-aminoantipriyne (AAP). The following results were obtained: 1. When guinea pigs were sensitized with paclitaxel or paclitaxel + OVA emulsified with Freund's complete adjuvant, none of active systemic anaphylaxis (ASA), passive cutaneous anaphylaxis (PCA) and Schultz-Dale reaction were induced by challenge with paclitaxel or paclitaxel + GSA (guinea pig serum albumin). In the observation of active cutaneous anaphylaxis (ACA), no changes were observed in animals treated with paclitaxel alone as a sensitizing and/or a challenging antigen under the condition where slight delayed type hypersensitivity was elicited in animals sensitized with paclitaxel + OVA and challenged with paclitaxel + GSA. 2. When mice were sensitized with paclitaxel or paclitaxel + OVA adsorbed to alum. sera of these animals revealed a negative reaction in PCA using rats by challenge with paclitaxel or paclitaxel + RSA (rat serum albumin). 3. Protein bindings of paclitaxel with the above albumins were more than 40%. As shown above, paclitaxel was considered not to possess antigenic property under the experimental condition. In addition, the dose levels of paclitaxel employed in the present experiment were confirmed not to suppress the immune response to OVA. PMID:7966458

Kawano, S; Ishikawa, K; Kohmura, H; Kadota, T; Takahashi, N

1994-08-01

50

Pharmacokinetic modeling of paclitaxel encapsulation in Cremophor EL micelles.  

PubMed

Nonlinear disposition of paclitaxel (Taxol) in cancer patients has been described in several studies, but the underlying mechanism is still a matter of speculation. Previously, we have shown in vitro that the paclitaxel formulation vehicle, Cremophor EL (CrEL), alters the blood distribution of paclitaxel as a result of entrapment of the compound in circulating CrEL micelles, thereby reducing the free drug fraction available for cellular partitioning. Based on these findings, we prospectively re-evaluated the linearity of paclitaxel disposition in patients using whole blood and plasma analysis, and sought to define a new pharmacokinetic model to describe the data. Seven patients with solid tumors were treated with paclitaxel infused over 3 h, each at consecutive 3-weekly dose levels of 225, 175 and 135 mg/m2 (CrEL dose level, 18.8, 14.6, and 11.3 ml/m2, respectively). Patient samples were collected up to 24 h after the start of infusion, and analyzed by high-performance liquid chromatography. Paclitaxel peak levels and areas under the curve in whole blood increased linearly with dose, whereas plasma levels showed substantial deviation from linearity. This was shown to be caused by a CrEL concentration-dependent decrease in paclitaxel uptake in blood cells, as reflected by the blood:plasma concentration ratios which altered significantly from 0.83 +/- 0.11 (at 135 mg/m2) to 0.68 +/- 0.07 (at 225 mg/m2). It is concluded that the nonlinear disposition of paclitaxel is related to paclitaxel dose-related levels of the formulation vehicle CrEL, leading to a disproportionate drug accumulation in the plasma fraction. The pharmacokinetic model developed accurately described the data, and will help guide future development and refinement of clinical protocols, especially in defining the exposure measure best linked to paclitaxel effects and toxicities. PMID:11345647

van Zuylen, L; Karlsson, M O; Verweij, J; Brouwer, E; de Bruijn, P; Nooter, K; Stoter, G; Sparreboom, A

2001-04-01

51

The Early Stages of Taxol Biosynthesis: An Interim Report on the Synthesis and Identification of Early Pathway Metabolites  

PubMed Central

The biosynthesis of the anti-cancer drug taxol (paclitaxel) has required the collaborative efforts of several research groups to tackle the synthesis and labeling of putative biosynthetic intermediates, in concert with the identification, cloning and functional expression of the biosynthetic genes responsible for the construction of this complex natural product. Based on a combination of precursor labeling and incorporation experiments, and metabolite isolation from Taxus spp., a picture of the complex matrix of pathway oxygenation reactions following formation of the first committed intermediate, taxa-4(5),11(12)-diene, is beginning to emerge. An overview of the current state of knowledge on the early-stages of taxol biosynthesis is presented.

Guerra-Bubb, Jennifer; Croteau, Rodney; Williams, Robert M.

2012-01-01

52

Inhibition of Paclitaxel-induced Decreases in Calcium Signaling*  

PubMed Central

Peripheral neuropathy is one of the most severe and irreversible side effects caused by treatment from several chemotherapeutic drugs, including paclitaxel (Taxol®) and vincristine. Strategies are needed that inhibit this unwanted side effect without altering the chemotherapeutic action of these drugs. We previously identified two proteins in the cellular pathway that lead to Taxol-induced peripheral neuropathy, neuronal calcium sensor-1 (NCS-1) and calpain. Prolonged treatment with Taxol induces activation of calpain, degradation of NCS-1, and loss of intracellular calcium signaling. This paper has focused on understanding the molecular basis for prevention of peripheral neuropathy by testing the effects of addition of two candidate compounds to the existing chemotherapeutic drug regime: lithium and ibudilast. We found that the co-administration of either lithium or ibudilast to neuroblastoma cells that were treated with Taxol or vincristine inhibited activation of calpain and the reductions in NCS-1 levels and calcium signaling associated with these chemotherapeutic drugs. The ability of Taxol to alter microtubule formation was unchanged by the addition of either candidate compound. These results allow us to suggest that it is possible to prevent the unnecessary and irreversible damage caused by chemotherapeutic drugs while still maintaining therapeutic efficacy. Specifically, the addition of either lithium or ibudilast to existing chemotherapy treatment protocols has the potential to prevent chemotherapy-induced peripheral neuropathy.

Benbow, Jennifer H.; Mann, Taylor; Keeler, Camille; Fan, Chengpeng; Hodsdon, Michael E.; Lolis, Elias; DeGray, Brenda; Ehrlich, Barbara E.

2012-01-01

53

Inhibition of paclitaxel-induced decreases in calcium signaling.  

PubMed

Peripheral neuropathy is one of the most severe and irreversible side effects caused by treatment from several chemotherapeutic drugs, including paclitaxel (Taxol®) and vincristine. Strategies are needed that inhibit this unwanted side effect without altering the chemotherapeutic action of these drugs. We previously identified two proteins in the cellular pathway that lead to Taxol-induced peripheral neuropathy, neuronal calcium sensor-1 (NCS-1) and calpain. Prolonged treatment with Taxol induces activation of calpain, degradation of NCS-1, and loss of intracellular calcium signaling. This paper has focused on understanding the molecular basis for prevention of peripheral neuropathy by testing the effects of addition of two candidate compounds to the existing chemotherapeutic drug regime: lithium and ibudilast. We found that the co-administration of either lithium or ibudilast to neuroblastoma cells that were treated with Taxol or vincristine inhibited activation of calpain and the reductions in NCS-1 levels and calcium signaling associated with these chemotherapeutic drugs. The ability of Taxol to alter microtubule formation was unchanged by the addition of either candidate compound. These results allow us to suggest that it is possible to prevent the unnecessary and irreversible damage caused by chemotherapeutic drugs while still maintaining therapeutic efficacy. Specifically, the addition of either lithium or ibudilast to existing chemotherapy treatment protocols has the potential to prevent chemotherapy-induced peripheral neuropathy. PMID:22988235

Benbow, Jennifer H; Mann, Taylor; Keeler, Camille; Fan, Chengpeng; Hodsdon, Michael E; Lolis, Elias; DeGray, Brenda; Ehrlich, Barbara E

2012-11-01

54

Arsenic Trioxide Suppresses Paclitaxel-Induced Mitotic Arrest  

PubMed Central

To human health, arsenic exhibits the property of a double-edged sword. Arsenic compounds such as As2O3 is effective for the treatment of relapsed/refractory acute promyelocytic leukemia, whereas chronic exposure to environmental arsenic is associated with the development of a variety of common cancers. Because As2O3 is capable of inhibiting tubulin polymerization and inducing mitotic arrest, we examined whether there existed any functional interaction between As2O3 and paclitaxel, a well-known microtubule poison. Flow cytometry and fluorescence microscopy revealed that although As2O3 alone caused a moderate level of mitotic arrest, it greatly attenuated paclitaxel-induced mitotic arrest in cells with p53 deficiency. Western blot analysis showed that As2O3 significantly blocked phosphorylation of BubR1, Cdc20, and Cdc27 in cells treated with paclitaxel, suggesting that arsenic compromised the activation of the spindle checkpoint. Our further studies revealed that the attenuation of paclitaxel-induced mitotic arrest by As2O3 resulted primarily from sluggish cell cycle progression at S phase but not enhanced mitotic exit. The clinical efficacy of taxol is associated with its ability to induce mitotic arrest and subsequent mitotic catastrophe. Our observations that As2O3 has a negative impact on the cell cycle checkpoint activation by taxol should have significant clinical implications.

Duan, Qing; Komissarova, Elena; Dai, Wei

2014-01-01

55

Paclitaxel loaded PEG(5000)-DSPE micelles as pulmonary delivery platform: formulation characterization, tissue distribution, plasma pharmacokinetics, and toxicological evaluation.  

PubMed

The objective of the present study was to evaluate the potential of paclitaxel loaded micelles fabricated from PEG(5000)-DSPE as a sustained release system following pulmonary delivery. PEG(5000)-DSPE micelles containing paclitaxel were prepared by solvent evaporation technique followed by investigation of in vitro release of paclitaxel in lung simulated fluid. Tissue distribution and plasma pharmacokinetics of the PEG-lipid micelles after intratracheal and intravenous administrations were investigated in addition to intratracheally administered taxol. Finally, toxicological profile of PEG(5000)-DSPE was investigated. Paclitaxel was successfully formulated in PEG-lipid micelles with encapsulation efficiency of 95%. The PEG-lipid micelles exhibited a sustained release behavior in the simulated lung fluid. Intratracheally administered polymeric micellar paclitaxel showed highest accumulation of paclitaxel in the lungs with AUC(0-12) in lungs being 45-fold higher than intravenously administered formulation and 3-fold higher than intratracheally delivered taxol. Paclitaxel concentration in other non-targeted tissues and plasma were significantly lower as compared to other groups. Furthermore, toxicity studies showed no significant increase in levels of lung injury markers in PEG(5000)-DSPE treated group as compared to saline-treated group. PEG(5000)-DSPE micelles delivered intratracheally were able to sustain highest paclitaxel concentrations in lungs for long periods of time, thus apprehending their suitability as pulmonary drug carriers. PMID:21575719

Gill, Kanwaldeep K; Nazzal, Sami; Kaddoumi, Amal

2011-10-01

56

Chronic exposure to paclitaxel diminishes phosphoinositide signaling by calpain-mediated neuronal calcium sensor-1 degradation  

PubMed Central

Paclitaxel (Taxol) is a well established chemotherapeutic agent for the treatment of solid tumors, but it is limited in its usefulness by the frequent induction of peripheral neuropathy. We found that prolonged exposure of a neuroblastoma cell line and primary rat dorsal root ganglia with therapeutic concentrations of Taxol leads to a reduction in inositol trisphosphate (InsP3)-mediated Ca2+ signaling. We also observed a Taxol-specific reduction in neuronal calcium sensor 1 (NCS-1) protein levels, a known modulator of InsP3 receptor (InsP3R) activity. This reduction was also found in peripheral neuronal tissue from Taxol treated animals. We further observed that short hairpin RNA-mediated NCS-1 knockdown had a similar effect on phosphoinositide-mediated Ca2+ signaling. When NCS-1 protein levels recovered, so did InsP3-mediated Ca2+ signaling. Inhibition of the Ca2+-activated protease ?-calpain prevented alterations in phosphoinositide-mediated Ca2+ signaling and NCS-1 protein levels. We also found that NCS-1 is readily degraded by ?-calpain in vitro and that ?-calpain activity is increased in Taxol but not vehicle-treated cells. From these results, we conclude that prolonged exposure to Taxol activates ?-calpain, which leads to the degradation of NCS-1, which, in turn, attenuates InsP3mediated Ca2+ signaling. These findings provide a previously undescribed approach to understanding and treating Taxol-induced peripheral neuropathy.

Boehmerle, Wolfgang; Zhang, Kun; Sivula, Michael; Heidrich, Felix M.; Lee, Yashang; Jordt, Sven-Eric; Ehrlich, Barbara E.

2007-01-01

57

Influence of Cremophor El on the bioavailability of intraperitoneal paclitaxel.  

PubMed

It has been hypothesized that the paclitaxel vehicle Cremophor EL (CrEL) is responsible for nonlinear drug disposition by micellar entrapment. To gain further insight into the role of CrEL in taxane pharmacology, we studied the pharmacokinetics of paclitaxel in the presence and absence of CrEL after i.p. and i.v. dosing. Patients received an i.p. tracer dose of [G-(3)H]paclitaxel in ethanol without CrEL (100 microCi diluted further in isotonic saline) on day 1, i.p. paclitaxel formulated in CrEL (Taxol; 125 mg/m(2)) on day 4, an i.v. tracer of [G-(3)H]paclitaxel on day 22, and i.v. Taxol (175 mg/m(2)) on day 24. Four patients (age range, 54-74 years) were studied, and serial plasma samples up to 72 h were obtained and analyzed for total radioactivity, paclitaxel, and CrEL. In the presence of CrEL, i.v. paclitaxel clearance was 10.2 +/- 3.76 liters/h/m(2) (mean +/- SD), consistent with previous findings. The terminal disposition half-life was substantially prolonged after i.p. dosing (17.0 +/- 11.3 versus 28.7 +/- 8.72 h), as was the mean residence time (7.28 +/- 2.76 versus 40.7 +/- 13.8 h). The bioavailability of paclitaxel was 31.4 +/- 5.18%, indicating insignificant systemic concentrations after i.p. treatment. CrEL levels were undetectable after i.p. dosing (<0.05 microl/ml), whereas after i.v. dosing, the mean clearance was 159 +/- 58.4 ml/h/m(2), in line with earlier observations. In the absence of CrEL, the bioavailability and systemic concentrations of i.p. paclitaxel were significantly increased. This finding is consistent with the postulated concept that CrEL is largely responsible for the pharmacokinetic advantage for peritoneal cavity exposure to total paclitaxel compared with systemic delivery. PMID:11948138

Gelderblom, Hans; Verweij, Jaap; van Zomeren, Desirée M; Buijs, Dirk; Ouwens, Linda; Nooter, Kees; Stoter, Gerrit; Sparreboom, Alex

2002-04-01

58

Free paclitaxel loaded PEGylated-paclitaxel nanoparticles: Preparation and comparison with other paclitaxel systems in vitro and in vivo.  

PubMed

Previously, PEGylated paclitaxel (PEG-PTX) was found not favorable as a polymer prodrug because of its poor antitumor efficiency. But surprisingly, it was found in our study that PEG-PTX could form a novel nanoparticle system with free PTX. To address how this system works, we compared PTX loaded PEG-PTX nanoparticles (PEG-PTX/PTX) with PTX loaded PEG-PLA micelles (PEG-PLA/PTX) or PTX injection available (Taxol(®)) in vitro and in vivo. Firstly, it was found that PEG-PTX/PTX was more stable in aqueous solution than PEG-PLA/PTX in terms of PTX crystal formation and drug release. Then it was demonstrated that coumarin loaded PEG-PTX nanoparticles had a much higher uptake in MCF-7 cells compared to coumarin loaded PEG-PLA micelles. The in vivo imaging study revealed that DIR or DID (near infrared fluorescent substances) loaded PEG-PTX nanoparticles distributed more in tumors in MCF-7 tumor bearing mice than DIR or DID loaded PEG-PLA micelles and solvent system of Taxol(®). In the efficacy study with MCF-7 tumor bearing mice, PEG-PTX/PTX showed significantly higher antitumor activity than PEG-PLA/PTX at the same PTX dosage. At the dose of 10mg free PTX per kg, PEG-PTX/PTX displayed similar efficacy as Taxol(®) but less toxicity evaluated by the loss of body weight. With the increase of free PTX to 15mg/kg, PEG-PTX/PTX showed significantly better efficacy than Taxol(®). In conclusion, with favorable characteristics in stability, cellular uptake, cytotoxicity, biodistribution, safety and efficacy, PEG-PTX/PTX seems highly potential as a nanocarrier for PTX delivery. PMID:24858391

Lu, Jingkai; Chuan, Xingxing; Zhang, Hua; Dai, Wenbing; Wang, Xinglin; Wang, Xueqing; Zhang, Qiang

2014-08-25

59

Adenocarcinoma cells exposed in vitro to Navelbine or Taxol increase Ep-CAM expression through a novel mechanism  

Microsoft Academic Search

Ep-CAM antigen expression was shown to vary by phase across the cell cycle. Following pretreatment of various adenocarcinoma cells in culture with clinically relevant concentrations of vinorelbine tartrate (Navelbine) or paclitaxel (Taxol), cell surface expression of Ep-CAM antigen increased by two- to ten-fold compared to that of untreated control cells and was associated with arrest of cell cycle progression and

Linda M. Thurmond; Julie B. Stimmel; Adrienne C. Ingram; Christian H. Ryan; Doris M. Murray; Derek J. Eberwein; Sam M. Witherspoon; Vincent C. Knick

2003-01-01

60

Taxol synergizes with antioxidants in inhibiting hormal refractory prostate cancer cell growth.  

PubMed

Taxanes are chemotherapeutic agents commonly used to treat various carcinomas. Dietary antioxidants, such as vitamin E, green tea extracts, and isoflavones have been used against prostate cancer, and exhibit anticancer effects both in vitro and in vivo. We evaluated the combined effect of taxol (paclitaxel) with pyrrolidine dithiocarbamate, vitamin E, epigallocatechin gallate, and genistein in killing hormone-refractory prostate cancer cells. Those agents were tested on the hormone-refractory prostate cancer cell line PC-3, and the viability of the cells was determined using MTT {3 (4, 5-dimethylthiazo-2-yl)-2, 5-diphenyl tetrazolium} assay after drug treatment. PC-3 cells were sensitive to these drugs with 50% inhibitory concentrations of 0.1, 23, 220, 1122, and 260 microM, for taxol, pyrrolidine dithiocarbamate, epigallocatechin gallate, genistein, and vitamin E, respectively. Genistein, pyrrolidine dithiocarbamate, and epigallocatechin gallate showed synergistic cytotoxicity to PC-3 cells when combined with 0.01 microM taxol. Only high concentration of vitamin E showed a synergistic effect with this dose of taxol. Further study revealed that 3 combinations could induce sub-G1 phase of cell cycle, induce apoptosis, and increase caspase activity and decrease Bcl-2 expression simultaneously. In conclusion, in addition to vitamin E, incorporation of these antioxidants with taxan-based cytotoxic therapies offers encouraging strategies for combating hormone-refractory prostate cancers. PMID:18818108

Ping, Szu-Yuan; Hour, Tzyh-Chyuan; Lin, Shinne-Ren; Yu, Dah-Shyong

2010-01-01

61

Synergistic effect of paclitaxel and epigenetic agent phenethyl isothiocyanate on growth inhibition, cell cycle arrest and apoptosis in breast cancer cells  

PubMed Central

This study examined whether combining paclitaxel (taxol) with a novel epigenetic agent phenethyl isothiocyanate (PEITC) will yield a synergistic effect on inhibiting breast cancer cells. Two drug-resistant breast cancer cell lines, MCF7 and MDA-MB-231, were treated with PEITC and taxol. Cell growth, cell cycle, and apoptosis were examined. The combination of PEITC and taxol significantly decreased the IC50 of PEITC and taxol over each agent alone. The combination also increased apoptosis by more than two fold over each single agent in both cell lines. A significant increase of cells in the G2/M phases was detected. In conclusion, the combination of PEITC and taxol exhibits a synergistic effect on growth inhibition in breast cancer cells. This combination deserves further study in vivo.

2013-01-01

62

Paclitaxel-Induced Apoptosis Is BAK-Dependent, but BAX and BIM-Independent in Breast Tumor  

PubMed Central

Paclitaxel (Taxol)-induced cell death requires the intrinsic cell death pathway, but the specific participants and the precise mechanisms are poorly understood. Previous studies indicate that a BH3-only protein BIM (BCL-2 Interacting Mediator of cell death) plays a role in paclitaxel-induced apoptosis. We show here that BIM is dispensable in apoptosis with paclitaxel treatment using bim?/? MEFs (mouse embryonic fibroblasts), the bim?/? mouse breast tumor model, and shRNA-mediated down-regulation of BIM in human breast cancer cells. In contrast, both bak?/? MEFs and human breast cancer cells in which BAK was down-regulated by shRNA were more resistant to paclitaxel. However, paclitaxel sensitivity was not affected in bax?/? MEFs or in human breast cancer cells in which BAX was down-regulated, suggesting that paclitaxel-induced apoptosis is BAK-dependent, but BAX-independent. In human breast cancer cells, paclitaxel treatment resulted in MCL-1 degradation which was prevented by a proteasome inhibitor, MG132. A Cdk inhibitor, roscovitine, blocked paclitaxel-induced MCL-1 degradation and apoptosis, suggesting that Cdk activation at mitotic arrest could induce subsequent MCL-1 degradation in a proteasome-dependent manner. BAK was associated with MCL-1 in untreated cells and became activated in concert with loss of MCL-1 expression and its release from the complex. Our data suggest that BAK is the mediator of paclitaxel-induced apoptosis and could be an alternative target for overcoming paclitaxel resistance.

Nakajima, Wataru; Richardson, Amanda C.; Windle, Jolene J.; Harada, Hisashi

2013-01-01

63

Paclitaxel-Conjugated PAMAM Dendrimers Adversely Affect Microtubule Structure through Two Independent Modes of Action  

PubMed Central

Paclitaxel (Taxol®) is an anti-cancer drug that induces mitotic arrest via microtubule hyperstabilization, but causes side effects due to its hydrophobicity and cellular promiscuity. The targeted cytotoxicity of hydrophilic paclitaxel-conjugated polyamidoamine (PAMAM) dendrimers has been demonstrated in cultured cancer cells. Mechanisms of action responsible for this cytotoxicity are unknown—i.e., whether the cytotoxicity is due to paclitaxel stabilization of microtubules — as is whether paclitaxel is released intracellularly from the dendrimer. To determine whether the conjugated paclitaxel can bind microtubules, we used a combination of ensemble and single microtubule imaging techniques in vitro. We demonstrate that these conjugates adversely affect microtubules by: (1) promoting the polymerization and stabilization of microtubules in a paclitaxel-dependent manner; and (2) bundling pre-formed microtubules in a paclitaxel-independent manner, potentially due to protonation of tertiary amines in the dendrimer interior. Our results provide mechanistic insights into the cytotoxicity of paclitaxel-conjugated PAMAM dendrimers and uncover unexpected risks of using such conjugates therapeutically.

Cline, Erika N.; Li, Ming-Hsin; Choi, Seok Ki; Herbstman, Jeffrey F.; Kaul, Neha; Meyhofer, Edgar; Skiniotis, Georgios; Baker, James R.; Larson, Ronald G.; Walter, Nils G.

2013-01-01

64

Inhibition of cancer cell proliferation and apoptosis-inducing activity of fungal taxol and its precursor baccatin III purified from endophytic Fusarium solani  

PubMed Central

Background Taxol (generic name paclitaxel), a plant-derived antineoplastic agent, used widely against breast, ovarian and lung cancer, was originally isolated from the bark of the Pacific yew, Taxus brevifolia. The limited supply of the drug has prompted efforts to find alternative sources, such as chemical synthesis, tissue and cell cultures of the Taxus species both of which are expensive and yield low levels. Fermentation processes with microorganisms would be the methods of choice to lower the costs and increase yields. Previously we have reported that F. solani isolated from T. celebica produced taxol and its precursor baccatin III in liquid grown cultures J Biosci 33:259-67, 2008. This study was performed to evaluate the inhibition of proliferation and induction of apoptosis of cancer cell lines by the fungal taxol and fungal baccatin III of F. solani isolated from T. celebica. Methods Cell lines such as HeLa, HepG2, Jurkat, Ovcar3 and T47D were cultured individually and treated with fungal taxol, baccatin III with or without caspase inhibitors according to experimental requirements. Their efficacy on apoptotic induction was examined. Results Both fungal taxol and baccatin III inhibited cell proliferation of a number of cancer cell lines with IC50 ranging from 0.005 to 0.2 ?M for fungal taxol and 2 to 5 ?M for fungal baccatin III. They also induced apoptosis in JR4-Jurkat cells with a possible involvement of anti-apoptotic Bcl2 and loss in mitochondrial membrane potential, and was unaffected by inhibitors of caspase-9,-2 or -3 but was prevented in presence of caspase-10 inhibitor. DNA fragmentation was also observed in cells treated with fungal taxol and baccatin III. Conclusions The cytotoxic activity exhibited by fungal taxol and baccatin III involves the same mechanism, dependent on caspase-10 and membrane potential loss of mitochondria, with taxol having far greater cytotoxic potential.

2013-01-01

65

Cremophor-free intravenous microemulsions for paclitaxel II. Stability, in vitro release and pharmacokinetics.  

PubMed

Two cremophor-free microemulsion systems LBMW (lecithin:butanol:myvacet:water) and CMW (capmul:myvacet:water), for intravenous (IV) administration of paclitaxel (PAC) were previously developed and characterized. Their chemical stability, in vitro release and pharmacokinetics of PAC were assessed using Taxol (cremophor:ethanol 1:1, 6 mg/ml) as a reference. The shelf-lives of PAC at 25 degrees C in Taxol, LBMW and CMW, in an accelerated stability study, were 71, 57 and 31 days, respectively. The activation energy (Ea) for PAC in Taxol, LBMW and CMW was 23, 16 and 14 kcal/mol, respectively. PAC released from LBMW and CMW using a dialysis technique was significantly slower than that from Taxol. The extents of release of PAC from LBMW and CMW were 25 and 50% of that from Taxol. In vivo pharmacokinetic studies in male Sprague-Dawley rats after IV administration revealed that PAC in LBMW and CMW remained in the systemic circulation five and two times longer and was eight and three times more widely distributed than PAC from Taxol. LBMW and CMW offer a significant clinical advantage in terms of the prolonged half-life and wide tissue distribution, indicating that PAC delivered by these systems intravenously may result in prolonged exposure of PAC to the tumor and subsequently an improved clinical efficacy. PMID:17869458

Nornoo, Adwoa O; Chow, Diana S-L

2008-02-12

66

Characterization of Polyclonal and Monoclonal Anti-Taxol Antibodies and Measurement of Taxol in Serum1  

Microsoft Academic Search

ABSTRACT Anti-taxol antibodies were generated in the rabbit using a taxol-bovine serum,albumin,conjugate prepared,from 2'-succinyltaxol using a mixed anhydride,procedure. Immunization,with 2'-succinyltaxol-bovine serum albumin,gave rise to polyclonal anti-taxol antibodies. By a radioimmu- noassay using [JH]taxol, a standard curve gave a 50% inhibitory concen tration of 1.0 MM. Taxol levels in human serum could be measured, with the lower limit of detection and

Jyh-Gang Leu; Bi-Xing Chen; Peter B. Schiff; Bernard F. Erlanger

67

Increased elimination of paclitaxel by magnesium isoglycyrrhizinate in epithelial ovarian cancer patients treated with paclitaxel plus cisplatin: a pilot clinical study.  

PubMed

Magnesium isoglycyrrhizinate (MI) has been complementarily used for restoring the hepatic impairments caused by taxol plus platinum based chemotherapies in China. Due to the hepatic dependence of paclitaxel elimination, this pilot clinical study aimed to investigate the influence of MI on the pharmacokinetics of paclitaxel in epithelial ovarian cancer patients. During the standard chemotherapy of intravenous paclitaxel (125 mg/m(2) infused over a 3-h period) and intraperitoneal cisplatin (60 mg/m(2)) for patients with FIGO stage II epithelial ovarian cancer, 9 each of total 18 patients were respectively treated with intravenous MI (100 mg) or vehicle control for 4 days. Plasma paclitaxel was analyzed by HPLC and the pharmacokinetic parameters were calculated with non-compartmental analysis. The hematological, hepatic and renal status was monitored before and 3 days after paclitaxel administration. It was observed the terminal t 1/2 and MRT of paclitaxel were significantly (p = 0.002 and 0.001) reduced by MI, respectively, from 11.0 ± 2.2 and 5.6 ± 1.0 h to 7.7 ± 1.7 and 4.0 ± 0.3 h. Hematological toxicity indicated by platelet count and hepatic events marked with ALT, AST and ?-GT were significant in both groups. In spite of the insignificance of decreased system exposure of paclitaxel and recovered hepatic function by MI, they did correlate with each other. It was therefore deduced that the liver toxicities of paclitaxel plus cisplatin chemotherapy potentially decrease hepatic elimination and increase system exposure of paclitaxel, and the recovery of liver function by MI helps to restore hepatic clearance of paclitaxel. The clinical significance of this pharmacokinetic interaction requires further studies with larger population size. PMID:23681836

Chen, Kai Jie; Chen, Wan Yi; Chen, Xia; Jia, Yi Ming; Peng, Gui Qin; Chen, Li

2014-03-01

68

[Preparation of superparamagnetic paclitaxel nanoparticles from modified chitosan and their cytotoxicity against malignant brain glioma].  

PubMed

We synthesized the superparamagnetic paclitaxel nanoparticles from modified chitosan tangling around Fe3O4 ferrofluid and taxol, and observed the nanoparticles with transmission electronic microscopy (TEM). Then we evaluated the paramagnetism of the particles by vibration specimen magnetometer (VSM) and tested their cytotoxicity with flow cytometry (FCM). The prepared nanoparticle solution was black without any floccule or sediment and appeared transparent after diluted. The nanoparticles were spherical and dispersed in water with mean diameter of 15 nm under TEM and showed superparamagnetic character. FCM test showed the nanoparticles had significant toxic effects against malignant astrocytoma U251 cell lines, equal to taxol alone. These results showed that the superparamagnetic nanoparticle not only enhanced the solubility of paclitaxel in water, but also was superparamagnetic and cytotoxic, which make suitable tools for magnetic targeting chemotherapy of brain gliomas. PMID:21774213

Zhao, Ming; Li, Anmin; Chang, Jin; Wang, Hanjie; Liang, Shuli; Zhang, Jiajing; Yan, Runmin

2011-06-01

69

Linearized Colorimetric Assay for Cremophor EL: Application to Pharmacokinetics after 1Hour Paclitaxel Infusions  

Microsoft Academic Search

Cremophor EL (CrEL) is a polyoxyethylated castor oil surfactant used in the intravenous formulation of the anticancer drug paclitaxel (Taxol). Quantitative determination of CrEL in patient samples can be achieved by complexation of the compound with the Coomassie brilliant blue G-250 dye in protein-free extracts [Sparreboom, A., Loos, W. J., Verweij, J., De Vos, A. I., Van der Burg, M.

Eric Brouwer; Jaap Verweij; Bernhard Hauns; Walter J. Loos; Kees Nooter; Klaus Mross; Gerrit Stoter; Alex Sparreboom

1998-01-01

70

Development of a supersaturable SEDDS (S-SEDDS) formulation of paclitaxel with improved oral bioavailability.  

PubMed

A new, supersaturable self-emulsifying drug delivery system (S-SEDDS) of paclitaxel was developed employing hydroxypropyl methylcellulose (HPMC) as a precipitation inhibitor with a conventional SEDDS formulation. In vitro dilution of the S-SEDDS formulation results in formation of a microemulsion, followed by slow crystallization of paclitaxel on standing. This result indicates that the system is supersaturated with respect to crystalline paclitaxel, and the supersaturated state is prolonged by HPMC in the formulation. In the absence of HPMC the SEDDS formulation undergoes rapid precipitation, yielding a low paclitaxel solution concentration. A pharmacokinetic study was conducted in male Sprague-Dawley rats to assess exposure after an oral paclitaxel dose of 10 mg/kg in the SEDDS formulations with (S-SEDDS) and without HPMC. The paclitaxel S-SEDDS formulation shows approximately 10-fold higher maximum concentration (C(max)) and five-fold higher oral bioavailability (F approximately 9.5%) compared with that of the orally dosed Taxol formulation (F approximately 2.0%) and the SEDDS formulation without HPMC (F approximately 1%). Coadministration of cyclosporin A (CsA), an inhibitor of P-glycoprotein and CYP 3A4 enzyme, at a dose of 5 mg/kg with the S-SEDDS formulation further increased the oral bioavailability (F approximately 22.6%). This assessment demonstrates that the systemic exposure of paclitaxel following oral administration can be substantially improved via the S-SEDDS approach. PMID:14603484

Gao, Ping; Rush, Bobby D; Pfund, William P; Huang, Tiehua; Bauer, Juliane M; Morozowich, Walter; Kuo, Ming-Shang; Hageman, Michael J

2003-12-01

71

Development of New Lipid-Based Paclitaxel Nanoparticles Using Sequential Simplex Optimization  

PubMed Central

The objective of these studies was to develop Cremophor-free lipid-based paclitaxel (PX) nanoparticle formulations prepared from warm microemulsion precursors. To identify and optimize new nanoparticles, experimental design was performed combining Taguchi array and sequential simplex optimization. The combination of Taguchi array and sequential simplex optimization efficiently directed the design of paclitaxel nanoparticles. Two optimized paclitaxel nanoparticles (NPs) were obtained: G78 NPs composed of glyceryl tridodecanoate (GT) and polyoxyethylene 20-stearyl ether (Brij 78), and BTM NPs composed of Miglyol 812, Brij 78 and D-alpha-tocopheryl polyethylene glycol 1000 succinate (TPGS). Both nanoparticles successfully entrapped paclitaxel at a final concentration of 150 ?g/ml (over 6% drug loading) with particle sizes less than 200 nm and over 85% of entrapment efficiency. These novel paclitaxel nanoparticles were stable at 4°C over three months and in PBS at 37°C over 102 hours as measured by physical stability. Release of paclitaxel was slow and sustained without initial burst release. Cytotoxicity studies in MDA-MB-231 cancer cells showed that both nanoparticles have similar anticancer activities compared to Taxol®. Interestingly, PX BTM nanocapsules could be lyophilized without cryoprotectants. The lyophilized powder comprised only of PX BTM NPs in water could be rapidly rehydrated with complete retention of original physicochemical properties, in-vitro release properties, and cytotoxicity profile. Sequential Simplex Optimization has been utilized to identify promising new lipid-based paclitaxel nanoparticles having useful attributes.

Dong, Xiaowei; Mattingly, Cynthia A.; Tseng, Michael; Cho, Moo; Adams, Val R.; Mumper, Russell J.

2008-01-01

72

Studies on Taxol(R) Biosynthesis. Preparation and Tritium Labeling of Biosynthetic intermediates by Deoxygenation of a Taxadiene Tetra-acetate Obtained from Japanese Yew  

PubMed Central

SUMMARY Taxa-4(20),11(12)-diene-5?-acetate 5 and Taxa-4(20), 11(12)-diene-5?-acetate, 10?-ol 6, have been identified as early stage intermediates involved in the biosynthesis of Taxol® (paclitaxel). Tritium-labeled 5 and 6 were successfully prepared by Barton deoxygenation using tri-n-butyltintritiide of the C-14-hydroxyl group of a taxoid obtained from Japanese Yew.

Horiguchi, Tohru; Rithner, Christopher D.; Croteau, Rodney; Williams, Robert M.

2010-01-01

73

Sensitizing the therapeutic efficacy of taxol with shikonin in human breast cancer cells.  

PubMed

Shikonin, a small-molecule natural product which inhibits the activity of pyruvate kinase M2 (PKM2), has been studied as an anti-cancer drug candidate in human cancer models. Here, our results demonstrate that shikonin is able to sensitize human breast cancer cells to chemotherapy by paclitaxel (taxol). Human breast adenocarcinoma MBA-MD-231 cells, which have higher levels of PKM2 expression and activity compared with MCF-7 cells, were selected to study further. The concentrations of shikonin and taxol were first selected at which they did not significantly induce cytotoxicity when treated alone, whereas the combination induced apoptosis. Surprisingly, PKM2 activity was decreased by shikonin, but not by the combination treatment. To identify the potential targets of this combination, human phospho-kinase antibody array analysis was performed and results indicated that the combination treatment inhibited the activation of ERK, Akt, and p70S6 kinases, which are known to contribute to breast cancer progression. Finally, how the combination affects breast cancer cell growth in vivo was tested using a xenograft tumor model. The results indicated that shikonin plus taxol prolonged animal survival and reduced tumor size than the vehicle treatment group. In summary, our results suggest that shikonin has a potential as an adjuvant for breast cancer therapy. PMID:24710512

Li, Wenjuan; Liu, Joan; Jackson, Kasey; Shi, Runhua; Zhao, Yunfeng

2014-01-01

74

Characterization of polyclonal and monoclonal anti-taxol antibodies and measurement of taxol in serum.  

PubMed

Anti-taxol antibodies were generated in the rabbit using a taxol-bovine serum albumin conjugate prepared from 2'-succinyltaxol using a mixed anhydride procedure. Immunization with 2'-succinyltaxol-bovine serum albumin gave rise to polyclonal anti-taxol antibodies. By a radioimmunoassay using [3H]taxol, a standard curve gave a 50% inhibitory concentration of 1.0 nM. Taxol levels in human serum could be measured, with the lower limit of detection and measurement being 0.1 nM or 0.085 ng/ml. Two mouse monoclonal anti-taxol antibodies were isolated by immunizing BALB/c mice with the same antigen. One was an immunoglobulin G1 (69E4A8E) and the other was immunoglobulin M (29B7B3C). The specificity of these antibodies was determined by a competitive enzyme-linked immunosorbent assay with taxol and 10 different related derivatives and analogues. 29B7B3C had higher binding affinities for biologically active derivatives and markedly lower affinities for inactive derivatives; i.e., the specificity was consistent with the results of tubulin disassembly and cytotoxicity studies using the same taxol derivatives, making it suitable for screening for taxol or taxol-like compounds in extracts of natural products. 69E4A8E recognized the benzamidocarbamyl group at the C-3' position of taxol and had a lower affinity for other active compounds with different substitutions. Taxol levels in human serum could be detected and measured by 69E4A8E using a competitive enzyme-linked immunosorbent assay. The lower limit of measurement was about 50 nM or approximately 42 ng/ml. Similar measurements could be made by radioimmunoassay. PMID:8095181

Leu, J G; Chen, B X; Schiff, P B; Erlanger, B F

1993-03-15

75

Taxol induces concentration-dependent apoptotic and paraptosis-like cell death in human lung adenocarcinoma (ASTC-a-1) cells.  

PubMed

Taxol (Paclitaxel) is an important natural product for the treatment of solid tumors such as ovarian, breast, non-small-cell lung tumors, and some head and neck carcinomas. Different concentrations of taxol trigger distinct effects on cell death forms. In present study, cell counting kit (CCK-8) assay, confocal fluorescence microscopy imaging, flow cytometry (FCM) and western blotting (WB) analysis were used to analyze the characteristics of cell death induced by low (35 nM) and high (70 microM) concentration of taxol respectively in human lung adenocarcinoma (ASTC-a-1) cells. Our results showed that low concentration of taxol induced cell death dominantly in apoptotic fashion associated with nuclear fragmentation, protein synthesis, phosphatidylserine (PS) externalization, G2/M cell cycle arrest, Bax translocation into mitochondria and caspase-3 activation, whereas high concentration of this drug induced significant cytoplasm vacuolization, mitochondria swelling and paraptosis-like cell death form without protein synthesis that is necessary for paraptosis. Although the mechanism of high concentration of taxol-induced paraptosis-like cell death has not been clear, this finding might have a potential implication for cancer therapy, especially for apoptosis-resistant cancer. PMID:20714087

Guo, Wen-Jing; Chen, Tong-Sheng; Wang, Xiao-Ping; Chen, Rong

2010-01-01

76

A novel paclitaxel-loaded poly(epsilon-caprolactone)/Poloxamer 188 blend nanoparticle overcoming multidrug resistance for cancer treatment.  

PubMed

Multidrug resistance (MDR) of tumor cells is a major obstacle to the success of cancer chemotherapy. Poloxamers have been used in cancer therapy to overcome MDR. The objective of this research is to test the feasibility of paclitaxel-loaded poly(epsilon-caprolactone)/Poloxamer 188 (PCL/Poloxamer 188) nanoparticles to overcome MDR in a paclitaxel-resistant human breast cancer cell line. Paclitaxel-loaded nanoparticles were prepared by a water-acetone solvent displacement method using commercial PCL and self-synthesized PCL/Poloxamer 188 compound, respectively. PCL/Poloxamer 188 nanoparticles were found to be of spherical shape and tended to have a rough and porous surface. The nanoparticles had an average size of around 220nm, with a narrow size distribution. The in vitro drug release profile of both nanoparticle formulations showed a clear biphasic release pattern. There was an increased level of uptake of PCL/Poloxamer 188 nanoparticles (PPNP) in the paclitaxel-resistant human breast cancer cell line MCF-7/TAX, in comparison with PCL nanoparticles. The cytotoxicity of PCL nanoparticles was higher than commercial Taxol in the MCF-7/TAX cell culture, but the differences were not significant. However, the PCL/Poloxamer 188 nanoparticles achieved a significantly higher level of cytotoxicity than both of PCL nanoparticle formulation and Taxol(R), indicating that paclitaxel-loaded PCL/Poloxamer 188 nanoparticles could overcome MDR in human breast cancer cells and therefore could have considerable therapeutic potential for breast cancer. PMID:19969111

Zhang, Yangqing; Tang, Lina; Sun, Leilei; Bao, Junbo; Song, Cunxian; Huang, Laiqiang; Liu, Kexin; Tian, Yan; Tian, Ge; Li, Zhen; Sun, Hongfan; Mei, Lin

2010-06-01

77

Cremophor EL-mediated alteration of paclitaxel distribution in human blood: clinical pharmacokinetic implications.  

PubMed

We have determined the in vitro and in vivo cellular distribution of the antineoplastic agent paclitaxel (Taxol) in human blood and the influence of Cremophor EL (CrEL), the vehicle used for i.v. drug administration. In the absence of CrEL, the blood:plasma concentration ratio was 1.07+/-0.004 (mean+/-SD). The addition of CrEL at concentrations corresponding to peak plasma levels achieved after the administration of paclitaxel (175 mg/m2 i.v. over a 3-h period; ie., 0.50%) resulted in a significant decrease in the concentration ratio (0.690+/-0.005; P < 0.05). Kinetic experiments revealed that this effect was caused by reduced erythrocyte uptake of paclitaxel by polyoxyethyleneglycerol triricinoleate, the major compound present in CrEL. Using equilibrium dialysis, it was shown that the affinity of paclitaxel for tested matrices was (in decreasing order) CrEL > plasma > human serum albumin, with CrEL present at or above the critical micellar concentration (approximately 0.01%). Our findings in the present study demonstrate a profound alteration of paclitaxel accumulation in erythrocytes caused by a trapping of the compound in CrEL micelles, thereby reducing the free drug fraction available for cellular partitioning. It is proposed that the nonlinearity of paclitaxel plasma disposition in patients reported previously should be reevaluated prospectively by measuring the free drug fractions and whole blood:plasma concentration ratios. PMID:10197613

Sparreboom, A; van Zuylen, L; Brouwer, E; Loos, W J; de Bruijn, P; Gelderblom, H; Pillay, M; Nooter, K; Stoter, G; Verweij, J

1999-04-01

78

Endophytic taxol-producing fungi from bald cypress, Taxodium distichum  

Microsoft Academic Search

as determined by the reactivity of partially purified culture extracts with specific monoclonal antibodies against taxol. In the case of one strain of P. microspora (CP-4), taxol was isolated from culture medium and was shown to be identical to authentic taxol by chromatographic and spectroscopic means.

Jia-yao Li; Gary Strobel; Rajinder Sidhu; W. M. Hess; E. J. Ford

1996-01-01

79

Novel Taxol formulation: polyvinylpyrrolidone nanoparticle-encapsulated Taxol for drug delivery in cancer therapy.  

PubMed

Taxol is a novel antitumor alkaloid that has shown clinical activity against several tumors. However, due to its low aqueous solubility, Cremophor EL (polyoxyethylated castor oil) and ethanol are used as excipients in the pharmaceutical drug formulations. These agents are implicated in hypersensitivity reactions. Hence the goal of this work was to design a novel Taxol formulation using polymeric nanoparticles to eliminate the Cremophor EL vehicle for drug delivery. Polyvinylpyrrolidone nanoparticles containing Taxol were prepared by a reverse microemulsion method. The size of the nanoparticles as determined by quasielastic light scattering was found to be between 50 and 60 nm. The antitumor effect of Taxol encapsulated nanoparticles was evaluated in B16F10 murine melanoma transplanted in C57B1/6 mice. The in vivo efficacy of Taxol-containing nanoparticles as measured by reduction in tumor volume and increased survival time was significantly greater than that of an equivalent concentration of free Taxol. These results suggest that encapsulation of Taxol in polymeric nanoparticles could be useful in improving its therapeutic efficacy in treatment of solid tumors. PMID:8938791

Sharma, D; Chelvi, T P; Kaur, J; Chakravorty, K; De, T K; Maitra, A; Ralhan, R

1996-01-01

80

Hyaluronic acid-coated nanostructured lipid carriers for targeting paclitaxel to cancer.  

PubMed

The aim of our study was to develop hyaluronic acid-coated, paclitaxel-loaded, nanostructured lipid carriers (HA-NLCs) prepared via electrostatic attraction for delivering paclitaxel (PTX) to tumors overexpressing CD44. First, cationic PTX-NLC was prepared by melt emulsion technology. Then, PTX-NLC were coated with hyaluronic acid (HA). The in vitro release of PTX was evaluated by the dialysis method. This analysis showed that PTX was released more slowly from HA-NLC than from Taxol®. The in vitro cytotoxicity of HA-NLC was investigated using the MTT method in B16, CT26 and HCT116 cell lines. The results showed that the cytotoxicity of HA-NLC against these three cancer cell lines was superior to that of Taxol®. The in vivo antitumor effect, the pharmacokinetics and the tissue distribution of HA-NLC were all evaluated in B16-bearing Kunming mice. The results showed that HA-NLC was better tolerated and had increased antitumor activity in B16-bearing Kunming mice compared with Taxol®. Furthermore, HA-NLC could prolong the circulation time of PTX in blood and increase the accumulation of PTX in the tumor. Therefore, HA-NLC prepared via electrostatic attraction was an effective carrier for delivering PTX to tumors overexpressing CD44. PMID:22776563

Yang, Xiao-Yan; Li, Yun-Xia; Li, Min; Zhang, Li; Feng, Li-Xia; Zhang, Na

2013-07-01

81

Tectorigenin sensitizes paclitaxel-resistant human ovarian cancer cells through downregulation of the Akt and NF?B pathway.  

PubMed

Paclitaxel (Taxol) is currently used as the front-line chemotherapeutic agent for several cancers including ovarian carcinoma; however, the drug frequently induces drug resistance through multiple mechanisms. The new strategy of using natural compounds in combination therapies is highly attractive because those compounds may enhance the efficacy of chemotherapy. In this study, we found that tectorigenin, an isoflavonoid isolated from flower of Pueraria thunbergiana, enhanced the growth-inhibitory effect of paclitaxel in paclitaxel-resistant ovarian cancer cells (MPSC1(TR), A2780(TR) and SKOV3(TR)) as well as their naive counterparts. The combination of tectorigenin with paclitaxel resulted in a synergistic apoptosis compared with either agent alone through activation of caspases-3, -8 and -9. Treatment with tectorigenin inhibited the nuclear translocation of NF?B and the expression of NF?B-dependent genes such as FLIP, XIAP, Bcl-2, Bcl-xL and COX-2, which are known to be associated with chemoresistance. In addition, the tectorigenin-paclitaxel combination inhibited the phosphorylation of I?B and IKK and the activation of Akt in paclitaxel-resistant cancer cells. Moreover, tectorigenin-paclitaxel-induced cell growth inhibition was enhanced by pretreatment with the Akt inhibitor LY294002 or overexpression of the dominant negative Akt (Akt-DN), but reduced by overexpression of constitutively activated Akt (Akt-Myr). Furthermore, we found that Akt-Myr, at least in part, reversed tectorigenin-paclitaxel-induced nuclear translocation of NF?B and the phosphorylation of I?B and IKK. These data suggest that tectorigenin could sensitize paclitaxel-resistant human ovarian cancer cells through inactivation of the Akt/IKK/I?B/NF?B signaling pathway, and promise a new intervention to chemosensitize paclitaxel-induced cytotoxicity in ovarian cancer. PMID:23027625

Yang, Yeong-In; Lee, Kyung-Tae; Park, Hee-Juhn; Kim, Tae Jin; Choi, Youn Seok; Shih, Ie-Ming; Choi, Jung-Hye

2012-12-01

82

Differential microRNA expression signatures and cell type-specific association with Taxol resistance in ovarian cancer cells  

PubMed Central

Paclitaxel (Taxol) resistance remains a major obstacle for the successful treatment of ovarian cancer. MicroRNAs (miRNAs) have oncogenic and tumor suppressor activity and are associated with poor prognosis phenotypes. miRNA screenings for this drug resistance are needed to estimate the prognosis of the disease and find better drug targets. miRNAs that were differentially expressed in Taxol-resistant ovarian cancer cells, compared with Taxol-sensitive cells, were screened by Illumina Human MicroRNA Expression BeadChips. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was used to identify target genes of selected miRNAs. Kaplan–Meier survival analysis was applied to identify dysregulated miRNAs in ovarian cancer patients using data from The Cancer Genome Atlas. A total of 82 miRNAs were identified in ovarian carcinoma cells compared to normal ovarian cells. miR-141, miR-106a, miR-200c, miR-96, and miR-378 were overexpressed, and miR-411, miR-432, miR-494, miR-409-3p, and miR-655 were underexpressed in ovarian cancer cells. Seventeen miRNAs were overexpressed in Taxol-resistant cells, including miR-663, miR-622, and HS_188. Underexpressed miRNAs in Taxol-sensitive cells included miR-497, miR-187, miR-195, and miR-107. We further showed miR-663 and miR-622 as significant prognosis markers of the chemo-resistant patient group. In particular, the downregulation of the two miRNAs was associated with better survival, perhaps increasing the sensitivity of cancer cells to Taxol. In the chemo-sensitive patient group, only miR-647 could be a prognosis marker. These miRNAs inhibit several interacting genes of p53 networks, especially in TUOS-3 and TUOS-4, and showed cell line-specific inhibition effects. Taken together, the data indicate that the three miRNAs are closely associated with Taxol resistance and potentially better prognosis factors. Our results suggest that these miRNAs were successfully and reliably identified and would be used in the development of miRNA therapies in treating ovarian cancer.

Kim, Yong-Wan; Kim, Eun Young; Jeon, Doin; Liu, Juinn-Lin; Kim, Helena Suhyun; Choi, Jin Woo; Ahn, Woong Shick

2014-01-01

83

Carboxymethyl-chitosan-tethered lipid vesicles: hybrid nanoblanket for oral delivery of paclitaxel.  

PubMed

We describe the development and evaluation of a hybrid lipopolymeric system comprising carboxymethyl chitosan (CMC), covalently tethered to phosphatidylethanolamine units on the surface of lipid nanovesicles, for oral delivery of paclitaxel. The bioploymer is intended to act as a blanket, thereby shielding the drug from harsh gastrointestinal conditions, whereas the lipid nanovesicle ensures high encapsulation efficiency of paclitaxel and its passive targeting to tumor. CMC-tethered nanovesicles (LN-C-PTX) in the size range of 200-300 nm improved the gastrointestinal resistance and mucoadhesion properties as compared with unmodified lipid nanovesicles (LN-PTX). Conjugation of CMC did not compromise the cytotoxic potential of paclitaxel yet facilitated the interaction and uptake of the nanovesicles by murine melanoma (B16F10) cells through an ATP-dependent process. CMC-conjugated nanovesicles, upon oral administration in rats, improved the plasma concentration profile of paclitaxel, with 1.5 fold increase in its bioavailability and 5.5 folds increase in elimination half life in comparison with Taxol. We also found that CMC in addition to providing a gastric resistant coating also imparted stealth character to the nanovesicles, thereby reducing their reticuloendothelial system (RES)-mediated uptake by liver and spleen and bypassing the need for PEGylation. In vivo efficacy in subcutaneous model of B16F10 showed significantly improved tumor growth inhibition and survival with CMC-tethered nanovesicles as compared with unmodified nanovesicles, both administered orally. LN-C-PTX exhibited therapeutic efficacy comparable to Taxol and Abraxane and also showed reduced toxicity and improved survival. Overall, these results suggest the therapeutic potential of CMC tethered nanovesicles as a platform for oral administration of paclitaxel and also unravel the ability of CMC to impart stealth character to the nanoparticles, thereby preventing their RES clearance. PMID:23721348

Joshi, Nitin; Saha, Rama; Shanmugam, Thanigaivel; Balakrishnan, Biji; More, Prachi; Banerjee, Rinti

2013-07-01

84

Hyaluronic acid-based hydrogel for regional delivery of paclitaxel to intraperitoneal tumors  

PubMed Central

Intraperitoneal (IP) chemotherapy is an effective way of treating local and regional malignancies confined in the peritoneal cavity such as ovarian cancer. However, a persistent major challenge in IP chemotherapy is the need to provide effective drug concentrations in the peritoneal cavity for an extended period of time. We hypothesized that hyaluronic acid (HA)-based in-situ crosslinkable hydrogel would serve as a carrier of paclitaxel (PTX) particles to improve their IP retention and therapeutic effects. In-vitro gel degradation and release kinetics studies demonstrated that HA gels could entrap microparticulate PTX (>100 ?m) and release the drug over 10 days, gradually degraded by hyaluronidase, but had limited effect on retention of Taxol, a 14-nm micelle form of PTX. When administered IP to tumor-bearing nude mice, PTX was best retained in the peritoneal cavity as PTX-gel (microparticulate PTX entrapped in the HA gel), whereas Taxol-gel and other Taxol-based formulations left negligible amount of PTX in the cavity after 14 days. Despite the increase in IP retention of PTX, PTX-gel did not further decrease the tumor burdens than Taxol-based formulations, presumably due to the limited dissolution of PTX. This result indicates that spatial availability of a drug does not necessarily translate to the enhanced anti-tumor effect unless it is accompanied by the temporal availability.

Bajaj, Gaurav; Kim, Mi Ran; Mohammed, Sulma I.; Yeo, Yoon

2012-01-01

85

Clinical and economic implications of the use of nanoparticle paclitaxel (Nanoxel) in India.  

PubMed

Paclitaxel (Taxol), one of the most commonly used chemotherapeutic agents, is poorly soluble in water and requires cremophor, which often causes infusion reactions, as a solvent. Nanoxel, a nanoparticle formulation of the taxane, has been approved by the Indian regulatory authority. In the present article, we aim to describe the experience with the use of Nanoxel in India and its clinical and economic implications. We present three retrospective series in a common practice environment and an economic model. The first series shows no reactions in 596 Nanoxel infusions; the second series shows comparable adverse events other than infusion reactions between 83 patients who received Nanoxel and 32 treated with conventional paclitaxel. The third reveals comparable clinical outcomes for 51 patients treated with Nanoxel or conventional paclitaxel for gastroesophageal tumors. Finally, we describe an economic model which estimates savings of 21 580 Indian rupees per cycle with Nanoxel vis-à-vis conventional paclitaxel in the treatment of solid tumors in India. In conclusion, in an era in which the greatest challenge we face as medical oncologists is how to conciliate hard-won and incremental--but small--improvements in survival with exponentially rising drugs costs, it is refreshing to see a potential new formulation of a commonly used drug that may actually generate cost-savings while improving clinical outcomes and patient well-being. Further studies are clearly warranted to determine the optimal dose and schedule for Nanoxel as well as its comparative effectiveness to cremophor-based paclitaxel. PMID:23975704

Ranade, A A; Joshi, D A; Phadke, G K; Patil, P P; Kasbekar, R B; Apte, T G; Dasare, R R; Mengde, S D; Parikh, P M; Bhattacharyya, G S; Lopes, G L

2013-09-01

86

Taxol-induced bundling of brain-derived microtubules  

PubMed Central

Taxol has two obvious effects in cells. It stabilizes microtubules and it induces microtubule bundling. We have duplicated the microtubule- bundling effect of taxol in vitro and report preliminary characterization of this bundling using electron microscopy, sedimentation, and electrophoretic analyses. Taxol-bundled microtubules from rat brain crude extracts were seen as massive bundles by electron microscopy. Bundled microtubules sedimented through sucrose five times faster than control microtubules. Electrophoretic analysis of control and taxol-bundled microtubules pelleted through sucrose revealed no striking differences between the two samples except for a protein doublet of approximately 100,000 daltons. Taxol-induced microtubule bundling was not produced by using pure tubulin or recycled microtubule protein; this suggested that taxol-induced microtubule bundling was mediated by a factor present in rat brain crude extracts. Taxol cross- linked rat brain crude extract microtubules were entirely labile to ATP in the millimolar range. This ATP-dependent relaxation was also demonstrated in a more purified system, using taxol-bundled microtubules pelleted through sucrose and gently resuspended. Although the bundling factor did not recycle with microtubule protein, it was apparently retained on isolated taxol-stabilized microtubules. The bundling factor was salt extracted from taxol-stabilized microtubules and its retained activity was demonstrated in an add-back experiment with assembled phosphocellulose-purified tubulin.

1984-01-01

87

A self-assembling nanoparticle for paclitaxel delivery in ovarian cancer.  

PubMed

Paclitaxel (PTX) is one of the most effective chemotherapeutic drugs for the treatment of a variety of cancers. However, it is associated with serious side effects caused by PTX itself and the Cremophor EL emulsifier. In the present study, we report the development of a well-defined amphiphilic linear-dendritic copolymer (named as telodendrimer) composed of polyethylene glycol (PEG), cholic acid (CA, a facial amphiphilic molecule) and lysine, which can form drug-loaded core/shell micelles when mixed with hydrophobic drug, such as PTX, under aqueous condition. We have used PEG(5k)-CA(8), a representive telodendrimer, to prepare paclitaxel-loaded nanoparticles (PTX-PEG(5k)-CA(8) NPs) with high loading capacity (7.3 mg PTX/mL) and a size of 20-60 nm. This novel nanoformulation of PTX was found to exhibit similar in vitro cytotoxic activity against ovarian cancer cells as the free drug (Taxol) or paclitaxel/human serum albumin nanoaggregate (Abraxane). The maximum tolerated doses (MTDs) of PTX-PEG(5k)-CA(8) NPs after single dose and five consecutive daily doses in mice were approximately 75 and 45 mg PTX/kg, respectively, which were 2.5-fold higher than those of Taxol. In both subcutaneous and orthotopic intraperitoneal murine models of ovarian cancer, PTX-PEG(5k)-CA(8) NPs achieved superior toxicity profiles and anti-tumor effects compared to Taxol and Abraxane at equivalent PTX doses, which were attributed to their preferential tumor accumulation, and deep penetration into tumor tissue, as confirmed by near infrared fluorescence (NIRF) imaging. PMID:19660809

Xiao, Kai; Luo, Juntao; Fowler, Wiley L; Li, Yuanpei; Lee, Joyce S; Xing, Li; Cheng, R Holland; Wang, Li; Lam, Kit S

2009-10-01

88

A phase I study of paclitaxel, cisplatin, and fluorouracil (TCF) for advanced gastric cancer  

Microsoft Academic Search

Purpose  A phase I study of TCF therapy, which consists of paclitaxel (TXL: Taxol) + cisplatin (CDDP) + 5-fluorouracil (5-FU), in advanced gastric cancer patients was performed to determine the recommended\\u000a dose (RD) for a phase II study by checking the dose-limiting toxicity (DLT) and maximum-tolerated dose (MTD) of 5-FU above\\u000a the fixed dose of TXL and CDDP.\\u000a \\u000a \\u000a \\u000a Methods  The doses of TXL and CDDP were

Takuo Hara; Kenji Omura; Makoto Hirano; Yasuyuki Asada; Yoshinori Munemoto; Junichi Sakamoto

2007-01-01

89

Cremophor EL-mediated alteration of paclitaxel distribution in human blood: clinical pharmacokinetic implications  

Microsoft Academic Search

We have determined the in vitro and in vivo cellular distribution of the\\u000a antineoplastic agent paclitaxel (Taxol) in human blood and the influence\\u000a of Cremophor EL (CrEL), the vehicle used for i.v. drug administration. In\\u000a the absence of CrEL, the blood:plasma concentration ratio was 1.07+\\/-0.004\\u000a (mean+\\/-SD). The addition of CrEL at concentrations corresponding to peak\\u000a plasma levels achieved after the

Alex Sparreboom; Lia van Zuylen; Eric Brouwer; Walter J. Loos; Peter de Bruijn; A. J. Gelderblom; Marrimuthoo Pillay; Kees Nooter; Gerrit Stoter; Jaap Verweij

1999-01-01

90

Human serum albumin: spectroscopic studies of the paclitaxel binding and proximity relationships with cisplatin and adriamycin.  

PubMed

The interactions of anti-cancer drugs with blood constituents, particularly with serum albumin (HSA) may have a major influence on drug pharmacology and efficacy. In the present work the binding of paclitaxel (trade name Taxol) to human serum albumin and its effect on cisplatin and adriamycin interactions has been investigated through UV/visible, CD, fluorescence spectroscopy and the inductively couplet plasma atomic emission spectroscopy method. Displacement studies with use of bilirubin, as a competitive agent provided relevant information about the location of the binding site in HSA as well as the possible multidrug interactions. PMID:15522412

Trynda-Lemiesz, Lilianna; Luczkowski, Marek

2004-11-01

91

Preclinical Evaluation of Genexol-PM, a Nanoparticle Formulation of Paclitaxel, as a Novel Radiosensitizer for the Treatment of Non-Small Cell Lung Cancer  

SciTech Connect

Purpose: A key research objective in radiation oncology is to identify agents that can improve chemoradiation therapy. Nanoparticle (NP) chemotherapeutics possess several properties, such as preferential accumulation in tumors, that are uniquely suited for chemoradiation therapy. To facilitate the clinical translation of NP chemotherapeutics in chemoradiation therapy, we conducted preclinical evaluation of Genexol-PM, the only clinically approved NP chemotherapeutic with a controlled drug release profile, as a radiosensitizer using non-small cell lung cancer (NSCLC) as a model disease. Methods and Materials: The physical characteristics and drug release profile of Genexol-PM were characterized. Genexol-PM's efficacy as a radiosensitizer was evaluated in vitro using NSCLC cell lines and in vivo using mouse xenograft models of NSCLC. Paclitaxel dose to normal lung and liver after Genexol-PM administration were quantified and compared with that after Taxol administration. Results: Genexol-PM has a size of 23.91 ± 0.41 nm and surface charge of ?8.1 ± 3.1 mV. It releases paclitaxel in a controlled release profile. In vitro evaluation of Genexol-PM as a radiosensitizer showed it is an effective radiosensitizer and is more effective than Taxol, its small molecule counterpart, at the half maximal inhibitory concentration. In vivo study of Genexol-PM as a radiosensitizer demonstrated that it is more effective as a radiosensitizer than Taxol. We also found that Genexol-PM leads to lower paclitaxel exposure to normal lung tissue than Taxol at 6 hours postadministration. Conclusions: We have demonstrated that Genexol-PM is more effective than Taxol as a radiosensitizer in the preclinical setting and holds high potential for clinical translation. Our data support the clinical evaluation of Genexol-PM in chemoradiation therapy for NSCLC.

Werner, Michael E.; Cummings, Natalie D.; Sethi, Manish; Wang, Edina C.; Sukumar, Rohit [Laboratory of Nano- and Translational Medicine, Department of Radiation Oncology, Lineberger Comprehensive Cancer Center, University of North Carolina-Chapel Hill, Chapel Hill, North Carolina (United States) [Laboratory of Nano- and Translational Medicine, Department of Radiation Oncology, Lineberger Comprehensive Cancer Center, University of North Carolina-Chapel Hill, Chapel Hill, North Carolina (United States); Carolina Center for Cancer Nanotechnology Excellence, University of North Carolina-Chapel Hill, Chapel Hill, North Carolina (United States); Moore, Dominic T. [Division of Biostatistics and Data Management, Lineberger Comprehensive Cancer Center, University of North Carolina-Chapel Hill, Chapel Hill, North Carolina (United States)] [Division of Biostatistics and Data Management, Lineberger Comprehensive Cancer Center, University of North Carolina-Chapel Hill, Chapel Hill, North Carolina (United States); Wang, Andrew Z., E-mail: zawang@med.unc.edu [Laboratory of Nano- and Translational Medicine, Department of Radiation Oncology, Lineberger Comprehensive Cancer Center, University of North Carolina-Chapel Hill, Chapel Hill, North Carolina (United States); Carolina Center for Cancer Nanotechnology Excellence, University of North Carolina-Chapel Hill, Chapel Hill, North Carolina (United States)

2013-07-01

92

Preclinical Evaluation of Genexol-PM, a Nanoparticle Formulation of Paclitaxel, as a Novel Radiosensitizer for the Treatment of Non-Small Cell Lung Cancer  

PubMed Central

Purpose A key research objective in radiation oncology is to identify agents that can improve chemoradiation therapy. Nanoparticle (NP) chemotherapeutics possess several properties, such as preferential accumulation in tumors, that are uniquely suited for chemoradiation therapy. To facilitate the clinical translation of NP chemotherapeutics in chemoradiation therapy, we conducted preclinical evaluation of Genexol-PM, the only clinically approved NP chemotherapeutic with a controlled drug release profile, as a radiosensitizer using non-small cell lung cancer (NSCLC) as a model disease. Methods and Materials The physical characteristics and drug release profile of Genexol-PM were characterized. Genexol-PM’s efficacy as a radiosensitizer was evaluated in vitro using NSCLC cell lines and in vivo using mouse xenograft models of NSCLC. Paclitaxel dose to normal lung and liver after Genexol-PM administration were quantified and compared with that after Taxol administration. Results Genexol-PM has a size of 23.91 ± 0.41 nm and surface charge of ?8.1 ± 3.1 mV. It releases paclitaxel in a controlled release profile. In vitro evaluation of Genexol-PM as a radiosensitizer showed it is an effective radiosensitizer and is more effective than Taxol, its small molecule counterpart, at the half maximal inhibitory concentration. In vivo study of Genexol-PM as a radiosensitizer demonstrated that it is more effective as a radiosensitizer than Taxol. We also found that Genexol-PM leads to lower paclitaxel exposure to normal lung tissue than Taxol at 6 hours postad-ministration. Conclusions We have demonstrated that Genexol-PM is more effective than Taxol as a radiosensitizer in the preclinical setting and holds high potential for clinical translation. Our data support the clinical evaluation of Genexol-PM in chemoradiation therapy for NSCLC.

Sethi, Manish; Wang, Edina C.; Sukumar, Rohit; Moore, Dominic T.; Wang, Andrew Z.

2013-01-01

93

Effects of 3-repeat tau on taxol mobility through microtubules  

NASA Astrophysics Data System (ADS)

Both the anti-cancer drug taxol and the microtubule-associated protein tau suppress dynamics of microtubules (MT). We have observed taxol mobility with full-length 3-repeat tau, one of six tau isoforms, using fluorescence recovery after photobleaching (FRAP) on MTs and compare with earlier results on recombinant full-length adult 4-repeat tau. Taxol mobility becomes highly sensitive to taxol concentration in the presence of 3-repeat tau (up to 1:1 molar ratio) as it does in the presence of 4-repeat tau, but is 2 to 3 times faster at low taxol concentrations. Fitting to a mean-field binding reaction model [J.L. Ross et.al, PNAS 101:12910-5 (2004)] suggests that the presence of 3-repeat tau enhances taxol movement through pores in the MT walls.

Park, Hyunjoo; Fygenson, Deborah; Kim, Mahn Won

2005-03-01

94

Transcriptional Profiling of Targets for Combination Therapy of Lung Carcinoma with Paclitaxel and Mitogen-activated Protein\\/Extracellular Signal-regulated Kinase Kinase Inhibitor1  

Microsoft Academic Search

A combination of paclitaxel (Taxol) and mitogen-activated protein\\/ extracellular signal-regulated kinase kinase (MEK\\/Erk) inhibitor repre- sents a rational new approach to chemotherapy. We performed Af- fymetrix microarray analysis to understand the global effects of this combination in lung carcinoma. Genes involved in cell cycle control, apoptosis, adhesion, proliferation, invasion, and metastasis were modu- lated. We observed similar patterns of gene

Debra J. Taxman; Jeffrey P. MacKeigan; Casey Clements; Daniel T. Bergstralh

2003-01-01

95

Second-line weekly paclitaxel in patients with inoperable non-small cell lung cancer who fail combination chemotherapy with cisplatin  

Microsoft Academic Search

This phase II study was designed to assess single-agent paclitaxel (Taxol®), as second-line chemotherapy. Eligibility criteria: pathological diagnosis of inoperable non-small cell lung cancer (NSCLC) relapsing or refractory to standard front-line platinum (P)-based chemotherapy, performance status ?3, normal lab tests, informed consent. Ineligibility criteria: history of second or third cancer (unless surgically cured), mental instability or impairment, pre-existing moderate\\/severe peripheral

Gianfranco Buccheri; Domenico Ferrigno

2004-01-01

96

2'-Behenoyl-Paclitaxel Conjugate Containing Lipid Nanoparticles for the Treatment of Metastatic Breast Cancer  

PubMed Central

The aim of these studies was to develop a novel 2’-behenoyl-paclitaxel (C22-PX) conjugate nanoparticle (NP) formulation for the treatment of metastatic breast cancer. A lipophilic paclitaxel derivative C22-PX was synthesized and incorporated into lipid-based NPs. Free C22-PX and its NP formulation were evaluated in a series of in-vitro and in-vivo studies. The results demonstrated that C22-PX NPs were much better tolerated and had significantly higher plasma and tumor AUCs compared to Taxol at the maximum tolerated dose (MTD) in a subcutaneous 4T1 mouse mammary carcinoma model. These benefits resulted in significantly improved antitumor efficacy with the NP-based formulation.

Ma, Ping; Benhabbour, S. Rahima; Feng, Lan; Mumper, Russell J

2012-01-01

97

2'-Behenoyl-paclitaxel conjugate containing lipid nanoparticles for the treatment of metastatic breast cancer.  

PubMed

The aim of these studies was to develop a novel 2'-behenoyl-paclitaxel (C22-PX) conjugate nanoparticle (NP) formulation for the treatment of metastatic breast cancer. A lipophilic paclitaxel derivative C22-PX was synthesized and incorporated into lipid-based NPs. Free C22-PX and its NP formulation were evaluated in a series of in vitro and in vivo studies. The results demonstrated that C22-PX NPs were much better tolerated and had significantly higher plasma and tumor AUCs compared to Taxol at the maximum tolerated dose (MTD) in a subcutaneous 4T1 mouse mammary carcinoma model. These benefits resulted in significantly improved antitumor efficacy with the NP-based formulation. PMID:22902506

Ma, Ping; Rahima Benhabbour, S; Feng, Lan; Mumper, Russell J

2013-07-01

98

Gene expression correlating with response to paclitaxel in ovarian carcinoma xenografts.  

PubMed

We have investigated gene expression profiles of human ovarian carcinomas in vivo during Taxol(R) (paclitaxel) treatment and observed a difference in expression. Nude mice bearing 1A9 or 1A9PTX22 xenografts were given 60 mg/kg of paclitaxel. Therapeutic efficacy was achieved for 1A9, while 1A9PTX22 did not respond. Tumor tissues harvested 4 and 24 h after treatment were evaluated by cDNA microarray against untreated tumors. Paclitaxel caused the modulation of more genes in 1A9 than in 1A9PTX22 tumors, in accordance to their therapeutic response. Most gene expression alterations were detected 24 h after paclitaxel administration and affected genes involved in various biological functions including cell cycle regulation and cell proliferation (CDC2, CDKN1A, PLAB, and TOP2A), apoptosis (BNIP3 and PIG8), signal transduction and transcriptional regulation (ARF1, ATF2, FOS, GNA11, HDAC3, MADH2, SLUG, and SPRY4), fatty acid biosynthesis and sterol metabolism (FDPS, IDI1, LIPA, and SC5D), and IFN-mediated signaling (G1P3, IFI16, IFI27, IFITM1, and ISG15). The modulation of two representative genes, CDKN1A and TOP2A, was validated by Northern analyses on a panel of seven ovarian carcinoma xenograft models undergoing treatment with paclitaxel. We found that the changes in expression level of these genes was strictly associated with the responsiveness to paclitaxel. Our study shows the feasibility of obtaining gene expression profiles of xenografted tumor models as a result of drug exposure. This in turn might provide insights related to the drugs' action in vivo that will anticipate the response to treatment manifested by tumors and could be the basis for novel approaches to molecular pharmacodynamics. PMID:14985451

Bani, Maria Rosa; Nicoletti, Maria Ines; Alkharouf, Nawal W; Ghilardi, Carmen; Petersen, David; Erba, Eugenio; Sausville, Edward A; Liu, Edison T; Giavazzi, Raffaella

2004-02-01

99

Preparation, characterization and properties of sterically stabilized paclitaxel-containing liposomes.  

PubMed

Paclitaxel (Taxol) is a diterpenoid isolated from Taxus brevifolia, approved by the FDA for the treatment of ovarian and breast cancers. Due to its low solubility in water, it is clinically administered dissolved in Cremophor EL, (polyethoxylated castor oil) and ethanol, which cause serious side effects. Inclusion of paclitaxel in liposomal formulations has proved to be a good approach to eliminating this vehicle and improving the drug's antitumor efficacy. We prepared different conventional and PEGylated liposomes containing paclitaxel and determined encapsulation efficiency, physical stability and drug leakage in human plasma. The best conventional liposome formulation was composed of ePC/PG 9:1, while for PEGylated liposomes the best composition was ePC/PG/CHOL/PEG(5000)-DPPE 9:1:2:0.7. PEGylated liposomes were found to be less stable during storage than the corresponding conventional liposomes and to have lower drug release in human plasma at 37 degrees C. In vitro cytotoxic activities were evaluated on HT-29 human colon adenocarcinoma and MeWo melanoma cell lines. After 2 and 48 h, conventional liposomes had the same cytotoxicity as free paclitaxel, while PEGylated liposomes were as active as free drug, only after 48 h. Pharmacokinetics and biodistribution were evaluated in Balb/c mice after i.v. injection of paclitaxel, formulated in Cremophor EL or in conventional or in PEGylated liposomes. Encapsulation of paclitaxel in conventional liposomes produced marked differences over the free drug pharmacokinetics. PEGylated liposomes were long-circulating liposomes, with an increased t(1/2) beta 48.6 h, against t(1/2) beta 9.27 h of conventional liposomes. Biodistribution studies showed a considerable decrease in drug uptake in MPS-containing organs (liver and spleen) at 0.5 and 3 h after injection with PEGylated compared to conventional liposomes. PMID:10640577

Crosasso, P; Ceruti, M; Brusa, P; Arpicco, S; Dosio, F; Cattel, L

2000-01-01

100

RASSF1A and the Taxol Response in Ovarian Cancer  

PubMed Central

The RASSF1A tumor suppressor gene is frequently inactivated by promoter methylation in human tumors. The RASSF1A protein forms an endogenous complex with tubulin and promotes the stabilization of microtubules. Loss of RASSF1A expression sensitizes cells to microtubule destabilizing stimuli. We have observed a strong correlation between the loss of RASSF1A expression and the development of Taxol resistance in primary ovarian cancer samples. Thus, we sought to determine if RASSF1A levels could dictate the response to Taxol and whether an epigenetic therapy approach might be able to reverse the Taxol resistant phenotype of RASSF1A negative ovarian tumor cells. We found that knocking down RASSF1A expression in an ovarian cancer cell line inhibited Taxol-mediated apoptosis and promoted cell survival during Taxol treatment. Moreover, using a combination of small molecule inhibitors of DNA Methyl Transferase enzymes, we were able restore RASSF1A expression and Taxol sensitivity. This identifies a role for RASSF1A in modulating the tumor response to Taxol and provides proof of principal for the use of epigenetic therapy to overcome Taxol resistance.

Kassler, Susannah; Donninger, Howard; Birrer, Michael J.; Clark, Geoffrey J.

2012-01-01

101

Weekly paclitaxel as first-line chemotherapy for elderly patients with metastatic breast cancer. A multicentre phase II trial.  

PubMed

Paclitaxel is a cytotoxic agent with proven antitumour activity in metastatic breast cancer. Weekly administration of paclitaxel has demonstrated sustained efficacy together with a more favourable toxicity profile (e.g. less myelotoxicity) than the 3-weekly administration. This study evaluates the activity and toxicity of weekly paclitaxel (Taxol(R)) as first-line chemotherapy in elderly patients (>70 years of age) with hormone-refractory metastatic breast cancer. Patients with metastatic breast cancer received 80 mg/m(2) paclitaxel administered weekly on days 1, 8 and 15 of a 28-day cycle. Additional cycles were given until disease progression, or unacceptable toxicity. A dose increase to 90 mg/m(2) was allowed in the absence of toxicity. 26 Patients received a total of 101 cycles (median 4, range 1-11). 22 patients completed at least two cycles (six administrations). In 23 patients who were evaluable for response, there were 10 partial responses (38%), 9 patients with stable disease (35%), while 4 patients had disease progression (15%). The median duration of response was 194 days (>6 months). Overall treatment was relatively well tolerated, but 8 patients (32%) had to prematurely discontinue treatment because of fatigue. Neuropathy >grade 1 was noted only after five or more cycles in 4 patients. Weekly paclitaxel at this dose and schedule is an effective treatment regimen in the elderly patient with metastatic breast cancer, and is feasible, but yields relevant fatigue in a subset of patients. PMID:14746852

ten Tije, A J; Smorenburg, C H; Seynaeve, C; Sparreboom, A; Schothorst, K L C; Kerkhofs, L G M; van Reisen, L G P M; Stoter, G; Bontenbal, M; Verweij, J

2004-02-01

102

A Dicarboxylic Fatty Acid Derivative of Paclitaxel for Albumin Assisted Drug Delivery  

PubMed Central

Paclitaxel is a potent chemotherapy for many cancers but it suffers from very poor solubility. Consequently the TAXOL formulation uses copious amounts of the surfactant Cremophor EL to solubilize the drug for injection resulting in severe hypersensitivity and neutropenia. In contrast to Cremophor EL, presented is a way to solubilize paclitaxel (PTX) by conjugation of a dicarboxylic fatty acid for specific binding to the ubiquitous protein, serum albumin. The conjugation chemistry was simplified to a single step using the activated anhydride form of 3-pentadecylglutaric (PDG) acid which is reactive to a variety of nucleophiles. The PDG derivative is less cytotoxic than the parent compound and was found to slowly hydrolyze to PTX (~5% over 72 h) in serum, tumor cytosol, and tumor tissue homogenate. When injected intravenously to tumor bearing mice, [3H]-PTX in the TAXOL formulation was cleared rapidly with a half-life of 7 hours. In the case of the PDG derivative of PTX, the drug is quickly distributed and approximately 20% of the injected dose remained in the vasculature experiencing a 23-h half-life. These improvements from modifying PTX with the PDG fatty acid present the opportunity for PDG to become a generic modification for the improvement of many therapeutics.

Hackett, Michael J.; Joolakanti, Shyamsunder; Hartranft, Megan E.; Guley, Patrick C.; Cho, Moo J.

2013-01-01

103

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and paclitaxel have cooperative in vivo effects against glioblastoma multiforme cells.  

PubMed

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) in conjunction with microtubule-targeting agents may be a promising novel anticancer treatment strategy. In vitro studies have suggested that relatively low concentrations of TRAIL enhance the lethality of paclitaxel (Taxol) against human cancer cells. The increased efficacy may be due to the triggering of caspase activation, resulting in mitotic checkpoint abrogation and catastrophe. We show here that wild-type p53 protects cells from caspase-dependent death induced by this therapeutic combination in vitro. We have now also developed an imaging-based model system to test the in vivo efficacy of combined TRAIL and Taxol, in which tumor growth and treatment response can be monitored noninvasively and in real-time. We further utilize bioluminescence, F18-fluorodeoxyglucose-positron emission tomography, and microscale computed tomography imaging to confirm the effects of combined treatment on tumors. These studies together provide the first in vivo confirmation that combined TRAIL plus paclitaxel results in better tumor control compared with either TRAIL or paclitaxel alone, and with no discernable increased normal tissue toxicity in the mouse. Interestingly, the in vivo antitumor response elicited by combined treatment was not affected by the p53 status of the tumor cells. These preclinical observations together suggest the therapeutic potential of combining TRAIL plus paclitaxel in cancer treatment, and support further preclinical and future clinical testing. PMID:19996278

Dorsey, Jay F; Mintz, Akiva; Tian, Xiaobing; Dowling, Melissa L; Plastaras, John P; Dicker, David T; Kao, Gary D; El-Deiry, Wafik S

2009-12-01

104

Impact of taxol on dermal papilla cells — A proteomics and bioinformatics analysis  

Microsoft Academic Search

Dermal papilla (DP) cells play a regulatory role in hair growth, and also play a role in alopecia (hair loss). However, effects of taxol, which is a widely used chemotherapy drug, on DP cells remain unclear, despite that theoretically taxol can impact on DP cells to contribute to taxol-induced alopecia. To better understand pathophysiology of taxol-induced damage in DP cells,

Pei-Hsiu Chen; Chih-Yuan Wang; Ching-Wu Hsia; Ming-Yi Ho; Ann Chen; Min-Jen Tseng; Yung-Fu Wu; Han-Min Chen; Tzu-Hao Huang; Hung-Te Liu; Hao-Ai Shui

2011-01-01

105

Heat shock protein 90 mediates macrophage activation by Taxol and bacterial lipopolysaccharide  

PubMed Central

Taxol, a plant-derived antitumor agent, stabilizes microtubules. Taxol also elicits cell signals in a manner indistinguishable from bacterial lipopolysaccharide (LPS). LPS-like actions of Taxol are controlled by the lps gene and are independent of binding to the known Taxol target, ?-tubulin. Using biotin-labeled Taxol, avidin-agarose affinity chromatography, and peptide mass fingerprinting, we identified two Taxol targets from mouse macrophages and brain as heat shock proteins (Hsps) of the 70- and 90-kDa families. Geldanamycin, a specific inhibitor of the Hsp 90 family, blocked the nuclear translocation of NF-?B and expression of tumor necrosis factor in macrophages treated with Taxol or with LPS. Geldanamycin did not block microtubule bundling by Taxol or macrophage activation by tumor necrosis factor. Thus, Taxol binds Hsps, and Hsp 90 helps mediate the activation of macrophages by Taxol and by LPS.

Byrd, Cynthia A.; Bornmann, William; Erdjument-Bromage, Hediye; Tempst, Paul; Pavletich, Nikola; Rosen, Neal; Nathan, Carl F.; Ding, Aihao

1999-01-01

106

Cytotoxicity of taxol in vitro against human and rat malignant brain tumors  

Microsoft Academic Search

Taxol is a novel antitumor alkaloid that has shown clinical activity against several tumors, including ovarian and breast carcinoma and melanoma. To evaluate taxol’s potential as a therapy for malignant brain tumors, we measured the sensitivity of four human (U87, U373, H80, and D324) and two rat (9L, F98) brain-tumor cell lines to taxol. The cells were exposed to taxol

Mitchell A. Cahan; Kevin A. Walter; O. Michael Colvin; Henry Brem

1994-01-01

107

The In vitro Subcellular Localization and In vivo Efficacy of Novel Chitosan\\/GMO Nanostructures containing Paclitaxel  

Microsoft Academic Search

Purpose  To determine the in vitro sub-cellular localization and in vivo efficacy of chitosan\\/GMO nanostructures containing paclitaxel (PTX) compared to a conventional PTX treatment (Taxol®).\\u000a \\u000a \\u000a \\u000a Methods  The sub-cellular localization of coumarin-6 labeled chitosan\\/GMO nanostructures was determined by confocal microscopy in MDA-MB-231\\u000a cells. The antitumor efficacy was evaluated in two separate studies using FOX-Chase (CB17) SCID Female-Mice MDA-MB-231 xenograph\\u000a model. Treatments consisted of

W. J. Trickler; A. A. Nagvekar; A. K. Dash

2009-01-01

108

Cremophor-free intravenous microemulsions for paclitaxel I: formulation, cytotoxicity and hemolysis.  

PubMed

Two cremophor-free microemulsions, lecithin:butanol:myvacet oil:water (LBMW) and capmul:myvacet oil:water (CMW) for paclitaxel (PAC) were developed for intravenous (i.v.) administration. Six surfactants and four oils were screened with various combinations for maximal water incorporation and PAC solubility. Microemulsion regions were subsequently determined in ternary phase diagrams. Cytotoxicity in an MDA-M231 human breast cancer cell line and hemolytic potential were assessed in these systems compared to Taxol (cremophor EL:ethanol, 1:1, 6 mgPAC/ml). The maximal water incorporation into the lecithin:butanol surfactant blend was greater than that incorporated into capmul when combined with the oils screened. PAC solubility in myvacet oil was increased 1389-fold over its aqueous solubility. LBMW had a larger microemulsion region (46.5% of total ternary phase diagram) than that seen with CMW (18.6%). The droplet size of the dispersed phase was 111.5 (4.18)nm for LBMW and 110.3 (8.09)nm for CMW. Cytotoxicity of PAC was in decreasing order of: Taxol>LBMW>CMW. The IC50 values for LBMW and CMW ranged from 4.5 to 5.7 and >10 microM, respectively, as compared to that of Taxol (1.3 to 1.8 microM). Eighty-three percent, 68%, and 63% of red blood cells remain unlysed at a formulation volume to blood ratio of 0.035 in LBMW, CMW and Taxol. Promising microemulsions, LBMW and CMW were developed that can incorporate approximately 12 mg/g of PAC, substantially higher than its aqueous solubility (10.8 microg/ml) and that in the Taxol vehicle (6 mg/ml). PAC retained its cytotoxicity in the LBMW and CMW and was less likely to cause hemolysis compared to Taxol. This higher drug loading results in a smaller vehicle volume in required doses of these formulations and potentially less vehicle-related side effects are anticipated. PMID:17869459

Nornoo, Adwoa O; Osborne, David W; Chow, Diana S-L

2008-02-12

109

Effect of taxol on the therapeutic efficacy of radioimmunotherapy  

SciTech Connect

This investigation was conducted to evaluate the potential of using taxol to maximize the therapeutic effectiveness of radioimmunotherapy. Published studies have shown taxol to be an effective radiosensitizer of tumors to external irradiation by blocking tumor cells in the G{sub 2}/M phases of the cell cycle. In vitro and in vivo studies were carried out to study the effect of low-dose taxol on the therapeutic effectiveness of I-131 anti-CEA monoclonal antibody (OEM-094-20856 MoAb) of human colonic carcinoma (LS-174T cell line). The in vitro clonogenic assay studies indicated taxol effectively enhanced the cell killing effect of I-131 MoAb.

Cheng, K.T.; Spicer, K.M.; Means, J. [Univ. of South Carolina, Charleston, SC (United States)

1994-05-01

110

Phase I Clinical and Pharmacokinetic Study of Taxol1  

Microsoft Academic Search

Taxol, selected for clinical trial because of its animal antitumor activity and unique structure and mechanism of action, was administered in Cremophor by i.v. infusion over 6 h in a phase I study. Eastern Cooper ative Oncology Group toxicity grading was used. Eighty-three taxol courses were administered to 34 patients. Grade 3-4 hypersensitivity reactions occurred in 4 of 13 courses

Peter H. Wiernik; Janice J. Strauman; Janice P. Dutcher; Richard B. Lipton; Elisabeth Paietta

1987-01-01

111

Influence of Cremophor EL and genetic polymorphisms on the pharmacokinetics of paclitaxel and its metabolites using a mechanism-based model.  

PubMed

The formulation vehicle Cremophor EL has previously been shown to affect paclitaxel kinetics, but it is not known whether it also affects the kinetics of paclitaxel metabolites. This information may be important for understanding paclitaxel metabolism in vivo and in the investigation of the role of genetic polymorphisms in the metabolizing enzymes CYP2C8 and CYP3A4/CYP3A5 and the ABCB1 transporter. In this study we used the population pharmacokinetic approach to explore the influence of predicted Cremophor EL concentrations on paclitaxel (Taxol) metabolites. In addition, correlations between genetic polymorphisms and enzyme activity with clearance of paclitaxel, its two primary metabolites, 6?-hydroxypaclitaxel and p-3'-hydroxypaclitaxel, and its secondary metabolite, 6?-p-3'-dihydroxypaclitaxel were investigated. Model building was based on 1156 samples from a study with 33 women undergoing paclitaxel treatment for gynecological cancer. Total concentrations of paclitaxel were fitted to a model described previously. One-compartment models characterized unbound metabolite concentrations. Total concentrations of 6?-hydroxypaclitaxel and p-3'-hydroxypaclitaxel were strongly dependent on predicted Cremophor EL concentrations, but this association was not found for 6?-p-3'-dihydroxypaclitaxel. Clearance of 6?-hydroxypaclitaxel (fraction metabolized) was significantly correlated (p < 0.05) to the ABCB1 allele G2677T/A. Individuals carrying the polymorphisms G/A (n = 3) or G/G (n = 5) showed a 30% increase, whereas individuals with polymorphism T/T (n = 8) showed a 27% decrease relative to those with the polymorphism G/T (n = 17). The correlation of G2677T/A with 6?-hydroxypaclitaxel has not been described previously but supports other findings of the ABCB1 transporter playing a part in paclitaxel metabolism. PMID:21056987

Fransson, Martin N; Gréen, Henrik; Litton, Jan-Eric; Friberg, Lena E

2011-02-01

112

Well-defined, size-tunable, multi-functional micelles for efficient paclitaxel delivery for cancer treatment  

PubMed Central

We have developed a well-defined and biocompatible amphiphilic telodendrimer system (PEG-b-dendritic oligo-cholic acid) which can self-assemble into multifunctional micelles in aqueous solution for efficient delivery of hydrophobic drugs such as paclitaxel. In this telodendrimer system, cholic acid is essential for the formation of stable micelles with high drug loading capacity, owing to its facial amphiphilicity. A series of telodendrimers with variable length of PEG chain and number of cholic acid in the dendritic blocks were synthesized. The structure and molecular weight of each of these telodendrimers were characterized, and their critical micellization concentration (CMC), drug-loading properties, particle sizes and cytotoxicity were examined and evaluated for further optimization for anticancer drug delivery. The sizes of the micelles, with and without paclitaxel loading, could be tuned from 11.5 to 21 nm and from 15 to 141 nm, respectively. Optical imaging studies in xenograft models demonstrated preferential uptakes of the smaller paclitaxel-loaded micelles (17–60 nm) by the tumor, and the larger micelles (150 nm) by the liver and lung. The toxicity and anti-tumor efficacy profiles of these paclitaxel-loaded micelles in xenograft models were found to be superior to those of Taxol® and Abraxane®.

Luo, Juntao; Xiao, Kai; Li, Yuanpei; Lee, Joyce S.; Shi, Lifang; Tan, Yih-Horng; Xing, Li; Cheng, R. Holland; Liu, Gang-Yu; Lam, Kit S.

2010-01-01

113

Taxol and Taxane Production by Taxomyces andreanae, an Endophytic Fungus of Pacific Yew  

Microsoft Academic Search

Taxomyces andreanae, a fungal endophyte, was isolated from the phloem (inner bark) of the Pacific yew, Taxus brevifolia. The fungus is hyphomyceteous and, when grown in a semi-synthetic liquid medium, produced taxol and related compounds. Taxol was identified by mass spectrometry, chromatography, and reactivity with monoclonal antibodies specific for taxol. Both [1-14C]acetic acid and L-[U-14C]phenylalanine served as precursors of [14C]taxol

Andrea Stierle; Gary Strobel; Donald Stierle

1993-01-01

114

Cytotoxicity of taxol in vitro against human and rat malignant brain tumors  

Microsoft Academic Search

Taxol is a novel antitumor alkaloid that has shown clinical activity against several tumors, including ovarian and breast carcinoma and melanoma. To evaluate taxol's potential as a therapy for malignant brain tumors, we measured the sensitivity of four human (U87, U373, H80, and D324) and two rat (9L, F98) brain-tumor cell lines to taxol. The cells were exposed to taxol

Mitchell A. Cahan; Kevin A. Walter; O. Michael Colvin; Henry Bremi

1994-01-01

115

Impact of taxol on dermal papilla cells--a proteomics and bioinformatics analysis.  

PubMed

Dermal papilla (DP) cells play a regulatory role in hair growth, and also play a role in alopecia (hair loss). However, effects of taxol, which is a widely used chemotherapy drug, on DP cells remain unclear, despite that theoretically taxol can impact on DP cells to contribute to taxol-induced alopecia. To better understand pathophysiology of taxol-induced damage in DP cells, morphological and biochemical analyses were performed to check whether taxol can cause apoptosis in cultured DP cells or not. If it can, proteomics and bioinformatics analyses were then performed to investigate the protein networks which are impacted by the taxol treatment. Our data showed that taxol can cause apoptotic damage in DP cells in a concentration-dependant manner, as demonstrated by various apoptotic markers. Proteomic analysis on DP cells treated with the lowest apoptosis-inducible concentration of taxol revealed that taxol can affect expression of proteins involved in Ca2+-regulated biological processes, vesicles transport, protein folding, reductive detoxification, and biomolecules metabolism. Furthermore, bioinformatics analysis indicated that taxol can impact on multiple biological networks. Taken together, this biochemical, proteomics, and bioinformatics data may give an insight into pathophysiology of taxol-induced damage in DP cells and shed light on mechanisms underlying taxol-induced alopecia. PMID:21989266

Chen, Pei-Hsiu; Wang, Chih-Yuan; Hsia, Ching-Wu; Ho, Ming-Yi; Chen, Ann; Tseng, Min-Jen; Wu, Yung-Fu; Chen, Han-Min; Huang, Tzu-Hao; Liu, Hung-Te; Shui, Hao-Ai

2011-11-18

116

Microtubule Changes and Cytotoxicity in Leukemic Cell Lines Treated with Taxol1  

Microsoft Academic Search

Taxol, a diterpenoid plant product that enhances the polymerization of tubulin, is currently entering clinical trials in the treatment of human leukemia. In order to develop an in vitro assay to predict tumor sensitivity to taxol, human leukemic cell lines were exposed to clinically achievable concentrations of taxol for relevant exposure periods. Changes in micro- tubules visualized by indirect immunofluorescencewere

Eric K. Rowinsky; Ross C. Donehower; J Jones; Robert W. Tucker

1988-01-01

117

A PEG-Fmoc conjugate as a nanocarrier for paclitaxel.  

PubMed

We report here that a simple, well-defined, and easy-to-scale up nanocarrier, PEG5000-lysyl-(?-Fmoc-?-t-Boc-lysine)2 conjugate (PEG-Fmoc), provides high loading capacity, excellent formulation stability and low systemic toxicity for paclitaxel (PTX), a first-line chemotherapeutic agent for various types of cancers. 9-Fluorenylmethoxycarbonyl (Fmoc) was incorporated into the nanocarrier as a functional building block to interact with drug molecules. PEG-Fmoc was synthesized via a three-step synthetic route, and it readily interacted with PTX to form mixed nanomicelles of small particle size (25-30 nm). The PTX loading capacity was about 36%, which stands well among the reported micellar systems. PTX entrapment in this micellar system is achieved largely via an Fmoc/PTX ?-? stacking interaction, which was demonstrated by fluorescence quenching studies and (13)C NMR. PTX formulated in PEG-Fmoc micelles demonstrated sustained release kinetics, and in vivo distribution study via near infrared fluorescence imaging demonstrated an effective delivery of Cy5.5-labled PTX to tumor sites. The maximal tolerated dose for PTX/PEG-Fmoc (MTD > 120 mg PTX/kg) is higher than those for most reported PTX formulations, and in vivo therapeutic study exhibited a significantly improved antitumor activity than Taxol, a clinically used formulation of PTX. Our system may hold promise as a simple, safe, and effective delivery system for PTX with a potential for rapid translation into clinical study. PMID:24856103

Zhang, Peng; Huang, Yixian; Liu, Hao; Marquez, Rebecca T; Lu, Jianqin; Zhao, Wenchen; Zhang, Xiaolan; Gao, Xiang; Li, Jiang; Venkataramanan, Raman; Xu, Liang; Li, Song

2014-08-01

118

Thermosensitive liposomal taxol formulation: heat-mediated targeted drug delivery in murine melanoma.  

PubMed

Taxol, an antitumour alkaloid which stabilizes microtubules, demonstrates marked activity against several tumours. However, due to its low aqueous solubility, Cremophor EL (polyoxyethylated castor oil) is used as the excipient in pharmaceutical drug preparations of taxol. This has toxic side effects, thereby limiting the clinical use of taxol in cancer therapy. The aim of this study was to design a novel taxol formulation using thermosensitive liposomes in order to eliminate the Cremophor EL vehicle and improve the antitumour activity of taxol by site-specific drug delivery. Temperature-sensitive liposomes encapsulating taxol were prepared using the natural lipids egg phosphatidylcholine and cholesterol in combination with ethanol. The liposomes have a phase transition temperature (Tm) of 43 degrees C. The in vivo efficacy of thermosensitive liposome encapsulated taxol was determined in B16F10 murine melanoma transplanted into C57BI/6 mice in combination with local hyperthermia. A significant reduction in tumour volume and an increase in survival time was observed in tumour-bearing mice treated with a combination of hyperthermia and thermosensitive liposome encapsulated taxol compared with animals treated with an equivalent dose of free taxol with or without hyperthermia. These results suggest that thermosensitive liposome encapsulated taxol in combination with hyperthermia may be useful in improving the therapeutic efficacy of taxol in the treatment of melanoma. PMID:9664145

Sharma, D; Chelvi, T P; Kaur, J; Ralhan, R

1998-06-01

119

Taxol induces caspase-independent cytoplasmic vacuolization and cell death  

Microsoft Academic Search

We for the first time used fluorescence technology to study and find the taxol-induced caspases-independent cytoplasm vacuolization and cell death resembling paraptosis in through ER and mitochondria swelling at single living ASTC-a-1 cell level.

Tong-sheng Chen

2008-01-01

120

Suppression of endotoxin-induced inflammation by taxol  

Microsoft Academic Search

The pathogenesis of acute lung injury includes transendothelial diapedesis of leukocytes into lung tissues and disruption of endothelial\\/epithelial barriers leading to protein- rich oedema. In vitro studies show that the microtubule network plays a role in the regulation of endothelial permeability as well as in neutrophil locomotion. It was hypothesised that the microtubule-stabilising agent, taxol, might attenuate inflammation and vascular

T. Mirzapoiazova; I. A. Kolosova; L. Moreno; S. Sammani; J. G. N. Garcia; A. D. Verin

2007-01-01

121

Stable paclitaxel formulations in oily contrast medium.  

PubMed

Stable paclitaxel/Lipiodol solutions as well as emulsions were developed for the treatment of solid tumors including hepatocellular carcinoma. Paclitaxel could be dissolved in Lipiodol, an oily contrast medium, but precipitated out and formed aggregates with time. Paclitaxel precipitation was due to the inter- and intra-molecular hydrogen bonding of paclitaxel molecules. Time-dependent paclitaxel aggregation was completely prevented by adding small amounts of additional solvents, which are miscible with Lipiodol. It was also notable that paclitaxel helped in stabilizing the water-in-oil (w/o) type emulsion of Lipiodol and Iopamiro. The stability, physical properties and in vitro drug release profiles of the stable paclitaxel solutions and emulsions were characterized. When the stable oily paclitaxel solution was used for the treatment of B16F10 melanoma in C57BL/6 mice, the malignant cells were eradicated completely in 2 weeks, whereas the solid tumor grew rapidly and metastasized to the thigh and to other organs in the control group. Also, the mice survived for more than 1 year after the paclitaxel treatment, whereas all of those in the control group died in 40 days. PMID:15653161

Lee, In-Hyun; Park, Yeong Taek; Roh, Kyungho; Chung, Hesson; Kwon, Ick Chan; Jeong, Seo Young

2005-02-01

122

[Fluorescence analysis of taxol-induced paraptosis-like independent of caspase-3 activation].  

PubMed

In the present report, the authors for the first time described the characteristics of taxol-induced paraptosis-like for the human lung adenocarcinoma cells (ASTC-a-1). CCK-8 was used to assay the inhibition of taxol on the cells viability. Cell viability was inhibited obviously 24 h after taxol treatment. Confocal fluorescence scanning microscope was used to monitor the morphology changes in cells with taxol treatment. Fluorescence resonance energy transfer (FRET) and acceptor photobleaching techniques were used to analyze the caspase-3 activation in the taxol-induced cell swelling and cell dearth. Taxol induced cell swelling, cytoplasmatic vacuolization and cell death without cell shrinkage, an apoptotic feature, and membrane rupture, a necrotic feature. The emission spectra of scat3 inside living cells expressed stably with scat3 were the same for control (without taxol). Further analysis with FRET and acceptor photobleaching techniques showed that the caspase-3 was not activated by taxol for the cytoplastic vacuoliazation cells expressed stably with scat3 plasmid, suggesting that caspase-3 is not involved in the taxol-inducecd cell swelling, cytoplasmatic vacuolization and cell death. These results show that taxol can induce a novel nonapoptotic PCD resembling the paraptosis in ASTC-a-1 cells. PMID:19271504

Chen, Tong-Sheng; Wang, Xiao-Ping; Sun, Lei; Wang, Hui-Ying; Wang, Long-Xiang

2008-11-01

123

Adenovirus-mediated p53 gene therapy and paclitaxel have synergistic efficacy in models of human head and neck, ovarian, prostate, and breast cancer.  

PubMed

Synergy (or antagonism) between two chemical agents is an in vitro empirical phenomenon, in which the observed effect of the combination is more (or less) than what would be predicted from the effects of each agent working alone. Although mathematical synergy is not directly provable in the clinical setting, it does predict a favorable outcome when the two therapeutics are combined in vivo and strongly suggests the presence of in vivo synergy. In contrast, overt antagonism warns of future problems. Sophisticated three-dimensional statistical modeling was used to evaluate the presence of synergistic, additive, or antagonistic efficacy between adenovirus (Ad)-mediated p53 gene therapy (p53 Ad) and paclitaxel (Taxol) in a panel of human tumor cell lines. Cells were either pretreated with paclitaxel 24 h before p53 Ad or treated with both agents simultaneously. Cell proliferation was measured 3 days later. Paclitaxel had synergistic or additive efficacy with p53 gene therapy. In no case was the interaction antagonistic. Cell cycle analysis demonstrated that p53 Ad arrested cells in G0/G1 prior to apoptotic cell death, whereas paclitaxel arrested cells in G2-M prior to apoptotic cell death. When combined, the relative concentration of each agent determined the dominant cellular response. These results are consistent with the previously reported cell cycle effects of p53 or paclitaxel, respectively; however, these data fail to explain the observed drug synergy. We found that low concentrations of paclitaxel (1-14 nM) increased the number of cells transduced by recombinant Ad 3-35% in a dose-dependent manner, which is one possible mechanism for the observed synergy. Of particular note, the concentrations of paclitaxel responsible for increased Ad transduction were lower than the concentrations required for microtubule condensation. The efficacy of combination therapy was also evaluated in vivo. In the p53null SK-OV-3 xenograft model of ovarian cancer, a dosing schedule of p53 Ad that, by itself, had a relatively minimal effect on tumor burden (16%) caused a much greater decrease in tumor burden (55%) when combined with paclitaxel. Greater combined efficacy was also observed in the p53mut DU-145 prostate, p53mut MDA-MB-468 breast, and p53mut MDA-MB-231 breast cancer xenograft models in vivo. In summary, p53 Ad for cancer shows enhanced efficacy when combined with paclitaxel. This combination is recommended for clinical cancer trials. PMID:9563876

Nielsen, L L; Lipari, P; Dell, J; Gurnani, M; Hajian, G

1998-04-01

124

Possible Side Effects of Carboplatin and Paclitaxel  

Cancer.gov

Page of 1Possible Side Effects of Carboplatin and Paclitaxel (Table Version Date: October 8, 2013) COMMON, SOME MAY BE SERIOUS In 100 people receiving Carboplatin and Paclitaxel, more than 20 and up to 100 may have: Hair loss Infection, especially when

125

Binding of taxol to human plasma, albumin and alpha 1-acid glycoprotein.  

PubMed

The binding of taxol to human plasma and to individual plasma proteins was studied by equilibrium dialysis. Taxol was found to bind extensively (about 95%) without a significant difference between healthy volunteers and cancer patients. At clinically relevant concentrations (0.1-6 microM), the binding was found to be concentration independent, indicating nonspecific hydrophobic binding. Human serum albumin and alpha 1-acid glycoprotein were found to contribute about equally to the binding, with a minor contribution from lipoproteins. None of the drugs commonly coadministered with taxol (dexamethasone, diphenhydramine, ranitidine, doxorubicin, 5-fluorouracil and cisplatin) altered the binding of taxol significantly. The protein binding of taxol was found to dramatically decrease the red blood cell uptake of taxol. PMID:8102493

Kumar, G N; Walle, U K; Bhalla, K N; Walle, T

1993-06-01

126

HPLC Determination of Taxol and Related Compounds in Taxus Plant Extracts  

Microsoft Academic Search

A sensitive and reproducible HPLC method, using a Curosil G column and gradient elution, was developed for the routine analysis of taxol (I) and six related taxanes, 10-desacetyl-7-epi-taxol (II), cephalomannine (III), 10-desacetyl taxol (IV), baccatin III (V), 10-desacetyl-7-epi-baccatin III (VI), and 10-desacetyl baccatin III (VII) in Taxus plant extracts. The method was linear for taxanes I-VII within the concentration range

W. J. Kopycki; H. N. Elsohly; J. D. McChesney

1994-01-01

127

Involvement of mitochondrial pathway in Taxol-induced apoptosis of human T24 bladder cancer cells  

Microsoft Academic Search

We examined a human urothelial cancer T24 cell line, which was exposed to clinically achievable concentrations of Taxol and detected the lethal effect of Taxol as measured by a cytotoxic dose-response curve. Marked nuclear condensation and the fragmentation of chromatin were observed by DAPI stain, DNA ladder formation, and flow cytometry at an LC90 concentration of 0.8 µg\\/ml Taxol, which

Sheau-Yun Yuan; Shih-Lan Hsu; Kan-Jen Tsai; Chi-Rei Yang

2002-01-01

128

Cell kill kinetics and cell cycle effects of taxol on human and hamster ovarian cell lines  

Microsoft Academic Search

Taxol is a clinically active anticancer drug, which exerts its cytotoxicity by the unique mechanism of polymerizing tubulin monomers into microtubules and stabilizing microtubules. Our studies with ovarian (hamster CHO and human A2780) cells showed that taxol is a phase-specific agent that is much more cytotoxic to mitotic cells than interphase cells. First, the dose-survival pattern of taxol resembled that

Narima M. Lopes; Earl G. Adams; Thomas W. Pitts; Bijoy K. Bhuyan

1993-01-01

129

Taxol-induced paraptosis-like A549 cell death is not senescence  

Microsoft Academic Search

Our previous studies have shown that taxol, a potent anticancer agent, induces caspase-independent cell death and cytoplasmic vacuolization in human lung cancer cells. However, the mechanisms of taxol-induced cytoplasmic vacuolization are poorly understood. Cytoplasmic vacuolization have been reported to be a characteristic of cell senescence. Here, we employed confocal fluorescence microscopy imaging to study the reversibility of taxol-induced cytoplasmic vacuolization

Chao-Yang Wang; Tong-Sheng Chen

2011-01-01

130

A Mixed Micellar Formulation Suitable for the Parenteral Administration of Taxol  

Microsoft Academic Search

Taxol is a promising antitumor agent with poor water solubility. Intravenous administration of a current taxol formulation in a non-aqueous vehicle containing Cremophor EL may cause allergic reactions and precipitation upon aqueous dilution. In this study a novel approach to formulate taxol in aqueous medium for i.v. delivery is described. The drug is solubilized in bile salt (BS)\\/phospholipid (PC) mixed

Hayat Alkan-Onyuksel; Suganthi Ramakrishnan; Hee-Byung Chai; John M. Pezzuto

1994-01-01

131

A Phosphoglycoprotein Associated with Taxol Resistance in J774.2 Cells1  

Microsoft Academic Search

Taxol is an inhibitor of cell replication that promotes the assembly of microtubules in vitro and in cells. In the murine macrophage-like cell line J774.2, a taxol-resistant subline (J7\\/ TAX-50) has been developed in vitro by growing the cells in increasing drug concentrations. These cells, which are approxi mately 800-fold resistant to taxol, display some cross-resistance to colchicine, vinblastine, puromycin,

Samar N. Roy; Susan Band Horwitz

1985-01-01

132

Radiosensitization of paclitaxel, etanidazole and paclitaxel+etanidazole nanoparticles on hypoxic human tumor cells in vitro  

Microsoft Academic Search

Paclitaxel and etanidazole are hypoxic radiosensitizers that exhibit cytotoxic action at different mechanisms. The poly(d,l-lactide-co-glycolide) (PLGA) nanoparticles containing paclitaxel, etanidazole and paclitaxel+etanidazole were prepared by o\\/w and w\\/o\\/w emulsification-solvent evaporation method. The morphology of the nanoparticles was investigated by scanning electron microscope (SEM). The drug encapsulation efficiency (EE) and release profile in vitro were measured by high-performance liquid chromatography (HPLC).

Cheng Jin; Ling Bai; Hong Wu; Furong Tian; Guozhen Guo

2007-01-01

133

Intratumoral injection of taxol in vivo suppresses A549 tumor showing cytoplasmic vacuolization.  

PubMed

Based on our recent in vitro studies, this report was designed to explore the mechanism by which high concentration of taxol (70 µM) induced paraptosis-like cell death in human lung carcinoma (A549) cells, and to evaluate the therapeutic efficacy of taxol using A549 tumor-bearing mice in vivo. Exposure of cells to taxol induced time-dependent cytotoxicity and cytoplasmic vacuolization without the involvement of Bax, Bak, Mcl-1, Bcl-XL, and caspase-3. Although taxol treatment induced activating transcription factor 6 (ATF6) cleavage indicative of endoplasmic reticulum (ER) stress, silencing ATF6 by shATF6 did not prevent taxol-induced both cytotoxcity and cytoplasmic vacuolization, suggesting that taxol-induced cytoplasmic vacuolization and cell death were not due to ER stress. Moreover, taxol-treated cells did not show DNA fragmentation and loss of mitochondrial membrane potential, the typical characteristics of apoptosis. In addition, taxol-induced cytoplasmic vacuolization did not show the cellular lysis, the characteristics of oncosis, and positive of ?-galactosidase, the characteristic of senescence, indicating that taxol induced paraptosis-like cell death is neither oncosis nor senescence. Moreover, our in vivo data showed that intratumoral injection of taxol (50 mg/kg) in A549 tumor xenograft mice on day 1 and day 19 potently suppressed tumor growth showing significant ER vacuolization without toxicity. In conclusion, high concentration of taxol exhibits a significant anticancer activity by inducing paraptosis-like cell death in vitro and in vivo, without significant toxicity, suggesting a promising therapeutic strategy for apoptosis-resistance cancer by inducing ER vacuolization. PMID:22134971

Wang, Chaoyang; Chen, Tongsheng

2012-04-01

134

In vivo efficacy of paclitaxel-loaded injectable in situ-forming gel against subcutaneous tumor growth.  

PubMed

Injectable in situ-forming gels have received considerable attention as localized drug delivery systems. Here, we examined a poly(ethylene glycol)-b-polycaprolactone (MPEG-PCL) diblock copolymer gel as an injectable drug depot for paclitaxel (Ptx). The copolymer solution remained liquid at room temperature and rapidly gelled in vivo at body temperature. In vitro experiments showed that Ptx was released from MPEG-PCL copolymer gels over the course of more than 14 days. Experiments employing intratumoral injection of saline (control), gel-only, Taxol, or Ptx-loaded gel into mice bearing B16F10 tumor xenografts showed that Ptx-loaded gel inhibited the growth of B16F10 tumors more effectively than did saline or gel alone. Further, intratumoral injection of Ptx-loaded gel was more efficacious in inhibiting the growth of B16F10 tumor over 10 days than was injection of Taxol. A histological analysis demonstrated an increase in necrotic tissue in tumors treated with Ptx-loaded gel. In conclusion, our data show that intratumoral injection of Ptx-loaded MPEG-PCL diblock copolymer yielded an in situ-forming gel that exhibited controlled Ptx release profile, and that was effective in treating localized solid tumors. PMID:20298770

Lee, Ju Young; Kim, Kyung Sook; Kang, Yun Mi; Kim, E Sle; Hwang, Sung-Joo; Lee, Hai Bang; Min, Byoung Hyun; Kim, Jae Ho; Kim, Moon Suk

2010-06-15

135

Amphiphilic carboxymethyl chitosan-quercetin conjugate with P-gp inhibitory properties for oral delivery of paclitaxel.  

PubMed

An amphiphilic carboxymethyl chitosan-quercetin (CQ) conjugate was designed and synthesized for oral delivery of paclitaxel (PTX) to improve its oral bioavailability by increasing its water solubility and bypassing the P-gp drug efflux pumps. CQ conjugate had low critical micelle concentration (55.14 ?g/mL), and could self assemble in aqueous condition to form polymeric micelles (PMs). PTX-loaded CQ PMs displayed a particle size of 185.8 ± 4.6 nm and polydispersity index (PDI) of 0.134 ± 0.056. The drug-loading content (DL) and entrapment efficiency (EE) were 33.62 ± 1.34% and 85.63 ± 1.26%, respectively. Moreover, PTX-loaded CQ PMs displayed similar sustained-release profile in simulated gastrointestinal fluids (pH 1.2/pH 6.8) and PBS (pH 7.4). In situ intestinal absorption experiment showed that PTX-loaded CQ PMs significantly improved the effective permeability of PTX as compared to verapamil (P < 0.01). Likewise, PTX-loaded CQ PMs significantly enhanced the oral bioavailability of PTX, resulting in strong antitumor efficacy against tumor xenograft models with better safety profile as compared to Taxol(®) and Taxol(®) with verapamil. Overall, the results implicate that CQ PMs are promising vehicles for the oral delivery of water-insoluble anticancer drugs. PMID:24927684

Wang, Xiaoying; Chen, Yihang; Dahmani, Fatima Zohra; Yin, Lifang; Zhou, Jianping; Yao, Jing

2014-08-01

136

Isolation of Colletotrichum gloeosporioides, a novel endophytic taxol-producing fungus from the leaves of a medicinal plant, Justicia gendarussa  

Microsoft Academic Search

Taxol is a potent anticancer drug used widely in the treatment of a variety of cancers. An endophytic fungus Colletotrichum gloeosporioides (strain JGC-9) was isolated from Justicia gendarussa, a medicinal plant and screened for taxol production. Th e fungus was identifi ed based on the morphology of the fungal culture and the characteristics of the spores and screened for taxol

V. Gangadevi; J. Muthumary

2008-01-01

137

In vitro cell cultures obtained from different explants of Corylus avellana produce Taxol and taxanes  

Microsoft Academic Search

BACKGROUND: Taxol is an effective antineoplastic agent, originally extracted from the bark of Taxus brevifolia with a low yield. Many attempts have been made to produce Taxol by chemical synthesis, semi-synthesis and plant tissue cultures. However, to date, the availability of this compound is not sufficient to satisfy the commercial requirements. The aim of the present work was to produce

Federica Bestoso; Laura Ottaggio; Andrea Armirotti; Alessandro Balbi; Gianluca Damonte; Paolo Degan; Mauro Mazzei; Francesca Cavalli; Bernardetta Ledda; Mariangela Miele

2006-01-01

138

Effects of Cremophor EL on distribution of Taxol to serum lipoproteins  

Microsoft Academic Search

The clinical formulation of the anti-tumour agent Taxol involves the use of a mixture of ethanol and Cremophor EL. Gel electrophoresis and density-gradient ultracentrifugation were used to detect effects of Taxol infusions on serum lipoproteins. Use of the Cremophor vehicle results in a decrease in the electrophoretic mobility of serum lipoproteins along with the appearance of a lipoprotein dissociation product.

E Sykes; K Woodburn; D Decker; D Kessel

1994-01-01

139

Effects of Cremophor EL on distribution of Taxol to serum lipoproteins.  

PubMed

The clinical formulation of the anti-tumour agent Taxol involves the use of a mixture of ethanol and Cremophor EL. Gel electrophoresis and density-gradient ultracentrifugation were used to detect effects of Taxol infusions on serum lipoproteins. Use of the Cremophor vehicle results in a decrease in the electrophoretic mobility of serum lipoproteins along with the appearance of a lipoprotein dissociation product. These effects persist during a 24 h infusion and for at least 1.5 h afterwards, and can be reproduced in vitro using purified high-density lipoprotein (HDL) or low-density lipoprotein (LDL). In control serum, Taxol binds to albumin > HDL, but after serum is exposed to Cremophor EL in vitro or in vivo substantial binding of Taxol to the lipoprotein dissociation product(s) was observed. The latter could represent an important factor in taxol biodistribution. PMID:7915910

Sykes, E; Woodburn, K; Decker, D; Kessel, D

1994-09-01

140

Modulating paclitaxel bioavailability for targeting prostate cancer  

Microsoft Academic Search

Four novel water-soluble peptide-paclitaxel conjugates were designed and synthesized as prostate-specific antigen (PSA)-activated prodrugs for prostate cancer therapy. These prodrugs were composed of a peptide, HSSKLQ or SSKYQ, each of which is selectively cleavable by PSA; a self-immolative linker, either para-aminobenzyl alcohol (PABS) or ethylene diamine (EDA); and the parent drug, paclitaxel. Introduction of a PABA or EDA linker between

Srinivas K. Kumar; Simon A. Williams; John T. Isaacs; Samuel R. Denmeade; Saeed R. Khan

2007-01-01

141

Management of paclitaxel-induced neurotoxicity  

Microsoft Academic Search

Paclitaxel exerts its antitumor activity by promoting microtubule assembly and stabilizing microtubules. Microtubules are\\u000a important for the development and maintenance of neurons. As a consequence, neurotoxicity is one of the drug’s major side\\u000a effects. The risk of neurotoxicity depends on dose, duration and schedule of paclitaxel. Risk increases for patients with\\u000a pre-existing conditions that may cause neuropathy (such as alcohol

Manisha Bhutani; Philomena M. Colucci; Heather Laird-Fick; Barbara A. Conley

2010-01-01

142

Improving anti-tumor activity with polymeric micelles entrapping paclitaxel in pulmonary carcinoma.  

PubMed

Nanoscale polymeric micelles have promising applications as drug delivery systems (DDS). In this work, to improve the anti-tumor activity and eliminate toxicity of the commercial formulation (cremophor EL and ethanol) of paclitaxel (PTX), we developed biodegradable poly(ethylene glycol)-poly(?-caprolactone) (MPEG-PCL) micelles entrapping PTX by a simple one-step solid dispersion method, which is without any surfactants or additives and is easy to scale up. In addition, the PTX micelles could be lyophilized into powder without any adjuvant and the re-dissolved PTX micelles are stable and homogeneous. The prepared PTX micelles have a mean particle size of 38.06 ± 2.30 nm, a polydispersity index of 0.168 ± 0.014, a drug loading of 14.89 ± 0.06% and an encapsulation efficiency of 99.25 ± 0.38%. A molecular modeling study implied that PTX interacted with PCL as a core, which was embraced by PEG as a shell. The encapsulation of PTX in polymeric micelles enhanced its cytotoxicity by increasing the uptake by LL/2 cells. A sustained in vitro release behavior and slow extravasation behavior from blood vessels in a transgenic zebrafish model were observed in the PTX micelles. Furthermore, compared with Taxol®, the PTX micelles were more effective in suppressing tumor growth in the subcutaneous LL/2 tumor model. The PTX micelles also inhibited metastases in the pulmonary metastatic LL/2 tumor model and prolonged survival in both mouse models. Pharmacokinetic and tissue distribution studies showed that after PTX was encapsulated in polymeric micelles, the biodistribution pattern of PTX was altered and the PTX concentration in tumors was increased compared with Taxol® after intravenous injection. In conclusion, we have developed a polymeric micelles entrapping PTX that enhanced cytotoxicity in vitro and improved anti-tumor activity in vivo with low systemic toxicity on pulmonary carcinoma. The biodegradable MPEG-PCL micelles entrapping PTX may have promising applications in pulmonary carcinoma therapy. PMID:22910790

Gong, Changyang; Xie, Yongmei; Wu, Qinjie; Wang, Yujun; Deng, Senyi; Xiong, Dake; Liu, Lei; Xiang, Mingli; Qian, Zhiyong; Wei, Yuquan

2012-09-28

143

Biological Assessment of Triazine Dendrimers as Candidate Platforms for Nanomedicine: Toxicological Profiles, Solution Behavior, Biodistribution, and Drug Release and Efficacy in a PEGylated, Paclitaxel Construct  

PubMed Central

The physicochemical characteristics, in vitro properties, and in vivo toxicity and efficacy of a third generation triazine dendrimer bearing approximately nine 2 kDa polyethylene glycol chains and twelve ester linked paclitaxel groups are reported. The hydrodynamic diameter of the neutral construct varies slightly with aqueous solvent ranging from 15.6–19.4 nm. Mass spectrometry and light scattering suggest radically different molecular weights with the former ~40 kDa mass consistent with expectation, and the latter 400 kDa mass consistent with a decameric structure and the observed hydrodynamic radii. HPLC can be used to assess purity as well as paclitaxel release, which is insignificant in organic solvents or aqueous solutions at neutral and low pH. Paclitaxel release occurs in vitro in human, rat, and mouse plasma and is non-linear, ranging from 7–20% cumulative release over a 48 hour incubation period. The construct is 2–3 orders of magnitude less toxic than Taxol® by weight in human hepatocarcinoma (Hep G2), porcine renal proximal tubule (LLC-PK1), and human colon carcinoma (LS174T) cells, but shows similar cytotoxicity to Abraxane® in LS174T cells. Both Taxol® and the construct appear to induce caspase 3-dependent apoptosis. The construct shows a low level of endotoxin, is not hemolytic and does not induce platelet aggregation in vitro, but does appear to reduce collagen-induced platelet aggregation in vitro. Furthermore, the dendrimer formulation slightly activates the complement system in vitro due most likely to the presence of trace amounts (<1%) of free paclitaxel. An animal study provided insight into the maximum tolerated dose (MTD) wherein 10, 25, 50 and 100 mg paclitaxel/kg of construct or Abraxane were administered once per week for three consecutive weeks to non-tumor bearing athymic nude mice. The construct showed in vivo toxicity comparable to Abraxane. Both formulations were found to be non-toxic at the administered doses, and the dendrimer had an acute MTD greater than the highest dose administered. In a prostate tumor model (PC-3-luc), efficacy was observed over 70 days with an arrest of tumor growth and lack of luciferase activity observed in the twice treated cohort.

Lo, Su-Tang; Stern, Stephan; Clogston, Jeffrey D.; Zheng, Jiwen; Adiseshaiah, Pavan P.; Dobrovolskaia, Marina; Lim, Jongdoo; Patri, Anil; Sun, Xiankai; Simanek, Eric E.

2010-01-01

144

Modulating paclitaxel bioavailability for targeting prostate cancer.  

PubMed

Four novel water-soluble peptide-paclitaxel conjugates were designed and synthesized as prostate-specific antigen (PSA)-activated prodrugs for prostate cancer therapy. These prodrugs were composed of a peptide, HSSKLQ or SSKYQ, each of which is selectively cleavable by PSA; a self-immolative linker, either para-aminobenzyl alcohol (PABS) or ethylene diamine (EDA); and the parent drug, paclitaxel. Introduction of a PABA or EDA linker between the peptide and paclitaxel in prodrugs 2-5 resulted in products with an increased rate of hydrolysis by PSA. The stability of prodrugs 2 and 3, with the PABA linker, was poor in the serum-containing medium because of the weak carbonate bond between the PABA and paclitaxel; however, this disadvantage was overcome by introducing a carbamate bond using an EDA linker in prodrugs 4 and 5. Thus, the incorporation of an EDA linker increased both the stability and PSA-mediated activation of these prodrugs. The cytotoxicity of each prodrug, as compared to paclitaxel, was determined against a variety of cell lines, including the PSA-secreting CWR22Rv1 prostate cancer cell line. The EDA-derived prodrug of paclitaxel 5 was stable and capable of being efficiently converted to an active drug that killed cells specifically in the presence of PSA, suggesting that this prodrug and similarly designed PSA-cleavable prodrugs may have potential as prostate cancer-specific therapeutic agents. PMID:17502149

Kumar, Srinivas K; Williams, Simon A; Isaacs, John T; Denmeade, Samuel R; Khan, Saeed R

2007-07-15

145

Src family kinases and paclitaxel sensitivity  

PubMed Central

Src-family Kinases (SFKs) participate in the regulation of proliferation, differentiation, apoptosis, autophagy, adhesion, migration, invasion and angiogenesis in normal and cancer cells. Abnormal expression of SFKs has been documented in cancers that arise in breast, colon, ovary, melanocyte, gastric mucosa, head and neck, pancreas, lung and brain. Targeting SFKs in cancer cells has been shown to be a promising therapeutic strategy in solid tumors, particularly in ovarian, colon and breast cancers. Paclitaxel is one of most widely used chemotherapeutic agents for the management of ovarian, breast, lung and head and neck cancers. As a microtubule-stabilizing agent, paclitaxel possesses both mitosis-dependent and mitosis-independent activities against cancer cells. A variety of mechanisms such as deregulation of P-glycoprotein, alteration of tubulin isotypes, alteration of microtubule-regulatory proteins, deregulation of apoptotic signaling pathways, mutation of tubulins and overexpression of copper transporters have been implicated in the development of primary or secondary resistance to paclitaxel. By affecting cancer cell survival, proliferation, autophagy, microtubule stability, motility, and/or angiogenesis, SFKs interact with mechanisms that regulate paclitaxel sensitivity. Inhibition of SFKs can potentiate the anti-tumor activity of paclitaxel by enhancing apoptosis, autophagy and microtubule stability. Based on pre-clinical observations, administration of SFK inhibitors in combination with paclitaxel could improve treatment for ovarian, breast, lung and head and neck cancers. Identification and validation of predictive biomarkers could also permit personalization of the therapy.

2011-01-01

146

Recent Advances in the Study of the Bioactive Conformation of Taxol  

PubMed Central

Paclitaxel is one of the most important chemotherapeutic drugs in the fight against cancer. This minireview covers the recent advances in the study of the bioactive conformation of paclitaxel in tubulin/microtubules. The tubulin-bound structure of paclitaxel has been studied by means of photoaffinity labeling, cryo-electron microscopy, solid-state NMR, molecular modeling, MD simulations and the synthesis of conformationally restrained analogues and paclitaxel mimics. The bioactive conformation of paclitaxel is important since it could provide critical information that would allow the design of novel analogues with simpler structures and/or increased potency against cancer.

Sun, Liang; Simmerling, Carlos; Ojima, Iwao

2011-01-01

147

The intracellular uptake of CD95 modified paclitaxel-loaded poly(lactic-co-glycolic acid) microparticles.  

PubMed

The CD95/CD95L receptor-ligand system is mainly recognised in the induction of apoptosis. However, it has also been shown that CD95L is over-expressed in many cancer types where it modulates immune-evasion and together with its receptor CD95 promotes tumour growth. Here, we show that CD95 surface modification of relatively large microparticles >0.5 ?m in diameter, including those made from biodegradable polylactic-co-glycolic acid (PLGA), enhances intracellular uptake by a range of CD95L expressing cells in a process akin to phagocytosis. Using this approach we describe the intracellular uptake of microparticles and agent delivery in neurons, medulloblastoma, breast and ovarian cancer cells in vitro. CD95 modified paclitaxel-loaded PLGA microparticles are shown to be significantly more effective compared to conventional paclitaxel therapy (Taxol) at the same dose in subcutaneous medulloblastoma (???P < 0.0001) and orthotopic ovarian cancer xenograft models where a >65-fold reduction in tumour bioluminescence was measured after treatment (?P = 0.012). This drug delivery platform represents a new way of manipulating the normally advantageous tumour CD95L over-expression towards a therapeutic strategy. CD95 functionalised drug carriers could contribute to the improved function of cytotoxics in cancer, potentially increasing drug targeting and efficacy whilst reducing toxicity. PMID:21824652

Ateh, Davidson D; Leinster, Veronica H; Lambert, Sally R; Shah, Afsha; Khan, Ayub; Walklin, Hazel J; Johnstone, Jennifer V; Ibrahim, Nader I; Kadam, Mustafa M; Malik, Zain; Gironès, Míriam; Veldhuis, Gert J; Warnes, Gary; Marino, Silvia; McNeish, Iain A; Martin, Joanne E

2011-11-01

148

Possible Side Effects of Cyclophosphamide, Doxorubicin, and Paclitaxel  

Cancer.gov

Page of 1Possible Side Effects of Cyclophosphamide, Doxorubicin, and Paclitaxel (Table Version Date: October 8, 2013) COMMON, SOME MAY BE SERIOUS In 100 people receiving Cyclophosphamide, Doxorubicin, and Paclitaxel, more than 20 and up to 100 may have: Hair

149

Live-Cell Analysis of Mitotic Spindle Formation in Taxol-Treated Cells  

PubMed Central

Taxol functions to suppress the dynamic behavior of individual microtubules, and induces multipolar mitotic spindles. However, little is known about the mechanisms by which taxol disrupts normal bipolar spindle assembly in vivo. Using live imaging of GFP-? tubulin expressing cells, we examined spindle assembly after taxol treatment. We find that as taxol-treated cells enter mitosis, there is a dramatic redistribution of the microtubule network from the centrosomes to the cell cortex. As they align there, the cortical microtubules recruit NuMA to their embedded ends, followed by the kinesin motor HSET. These cortical microtubules then bud off to form cytasters, which fuse into multipolar spindles. Cytoplasmic dynein and dynactin do not re-localize to cortical microtubules, and disruption of dynein/dynactin interactions by over-expression of p50 “dynamitin” does not prevent cytaster formation. Taxol added well before spindle poles begin to form induces multipolarity, but taxol added after nascent spindle poles are visible—but before NEB is complete—results in bipolar spindles. Our results suggest that taxol prevents rapid transport of key components, such as NuMA, to the nascent spindle poles. The net result is loss of mitotic spindle pole cohesion, microtubule re-distribution, and cytaster formation.

Hornick, Jessica E.; Bader, Jason R.; Tribble, Emily K.; Trimble, Kayleigh; Breunig, J. Scott; Halpin, Elizabeth S.; Vaughan, Kevin T.; Hinchcliffe, Edward H.

2009-01-01

150

Effect of taxol on secretory cells: functional, morphological, and electrophysiological correlates  

PubMed Central

The effect of 0.5-1.0 microM taxol, a potent promoter of microtubule polymerization in vitro, was studied on the secretory activity of chromaffin cells of the adrenal medulla. Taxol was found to have a dual effect: the long-term effect (after a 1-h incubation) of taxol was to induce almost complete inhibition of catecholamine release, whereas after a short incubation (10 min) a massive, nicotine-independent release of catecholamine was produced. From results obtained using the patch-clamp technique to study the Ca++-dependent K+ channels (Ic channels), it was possible to conclude that taxol probably provokes an augmentation of free [Ca++]i in the cytoplasm, values increasing from 10(-8) M at rest to several 10(-7) M. The increased spontaneous release of stored neurohormones and the increased frequency of opening of Ic channels occur simultaneously and could both originate from a rise of [Ca++]i upon taxol addition. Immunofluorescence and ultrastructural studies showed that 13-h taxol treatment of chromaffin cells led to a different distribution of secretory organelles, and also to microtubule reorganization. In treated cells, microtubules were found to form bundles beneath the cell membrane and, at the ultrastructural level, to be packed along the cell axis. It is concluded that in addition to its action on microtubules, the antitumor drug taxol has side effects on the cell secretory activity, one of them being to modify free [Ca++]i.

1985-01-01

151

Inhibition of P-glycoprotein-mediated paclitaxel resistance by reversibly linked quinine homodimers.  

PubMed

P-glycoprotein (P-gp), an ATP-dependent drug efflux pump, has been implicated in multidrug resistance of several cancers as a result of its overexpression. In this work, rationally designed second-generation P-gp inhibitors are disclosed, based on dimerized versions of the substrates quinine and quinidine. These dimeric agents include reversible tethers with a built-in clearance mechanism. The designed agents were potent inhibitors of rhodamine 123 efflux in cultured cancer cell lines that display high levels of P-gp expression at the cell surface and in transfected cells expressing P-gp. The quinine homodimer Q2, which was tethered by reversible ester bonds, was particularly potent (IC(50) approximately 1.7 microM). Further studies revealed that Q2 inhibited the efflux of a range of fluorescent substrates (rhodamine 123, doxorubicin, mitoxantrone, and BODIPY-FL-prazosin) from MCF-7/DX1 cells. The reversibility of the tether was confirmed in experiments showing that Q2 was readily hydrolyzed by esterases in vitro (t(1/2) approximately 20 h) while demonstrating high resistance to nonenzymatic hydrolysis in cell culture media (t(1/2) approximately 21 days). Specific inhibition of [(125)I]iodoarylazidoprazosin binding to P-gp by Q2 verified that the bivalent agent interacted specifically with the drug binding site(s) of P-gp. Q2 was also an inhibitor of verapamil-stimulated ATPase activity. In addition, low concentrations of Q2 stimulated basal P-gp ATPase levels. Finally, Q2 was shown to inhibit the transport of radiolabeled paclitaxel (Taxol) in MCF-7/DX1 cells, and it completely reversed the P-gp-mediated paclitaxel resistance phenotype. PMID:18945821

Pires, Marcos M; Emmert, Dana; Hrycyna, Christine A; Chmielewski, Jean

2009-01-01

152

Systems pharmacological analysis of paclitaxel-mediated tumor priming that enhances nanocarrier deposition and efficacy.  

PubMed

Paclitaxel (PAC)-mediated apoptosis decompresses and primes tumors for enhanced deposition of nanoparticulate agents such as pegylated liposomal doxorubicin (DXR). A quantitative pharmacokinetic/pharmacodynamic (PK/PD) approach was developed to analyze efficacy and identify optima for PAC combined with sterically stabilized liposome (SSL)-DXR. Using data extracted from diverse literature sources, Cremophor-paclitaxel (Taxol(®)) PK was described by a carrier-mediated dispositional model and SSL-DXR PK was described by a two-compartment model with first-order drug release. A hybrid-physiologic, well-stirred model with partition coefficients (Kp) captured intratumor concentrations. Apoptotic responses driving tumor priming were modeled using nonlinear, time-dependent transduction functions. The tumor growth model used net first-order growth and death rate constants, and two transit compartments that captured the temporal displacement of tumor exposure versus effect, and apoptotic signals from each agent were used to drive cytotoxic effects of the combination. The final model captured plasma and intratumor PK data, apoptosis induction profiles, and tumor growth for all treatments/sequences. A feedback loop representing PAC-induced apoptosis effects on Kp(_DXR) enabled the model to capture tumor-priming effects. Simulations to explore time- and sequence-dependent effects of priming indicated that PAC priming increased K(p_DXR) 3-fold. The intratumor concentrations producing maximal and half-maximal effects were 18 and 7.2 ?g/ml for PAC, and 17.6 and 14.3 ?g/ml for SSL-DXR. The duration of drug-induced apoptosis was 27.4 h for PAC and 15.8 h for SSL-DXR. Simulations suggested that PAC administered 24 h before peak priming could increase efficacy 2.5-fold over experimentally reported results. The quantitative approach developed in this article is applicable for evaluating tumor-priming strategies using diverse agents. PMID:23115220

Ait-Oudhia, Sihem; Straubinger, Robert M; Mager, Donald E

2013-01-01

153

Systems Pharmacological Analysis of Paclitaxel-Mediated Tumor Priming That Enhances Nanocarrier Deposition and Efficacy  

PubMed Central

Paclitaxel (PAC)-mediated apoptosis decompresses and primes tumors for enhanced deposition of nanoparticulate agents such as pegylated liposomal doxorubicin (DXR). A quantitative pharmacokinetic/pharmacodynamic (PK/PD) approach was developed to analyze efficacy and identify optima for PAC combined with sterically stabilized liposome (SSL)-DXR. Using data extracted from diverse literature sources, Cremophor-paclitaxel (Taxol®) PK was described by a carrier-mediated dispositional model and SSL-DXR PK was described by a two-compartment model with first-order drug release. A hybrid-physiologic, well-stirred model with partition coefficients (Kp) captured intratumor concentrations. Apoptotic responses driving tumor priming were modeled using nonlinear, time-dependent transduction functions. The tumor growth model used net first-order growth and death rate constants, and two transit compartments that captured the temporal displacement of tumor exposure versus effect, and apoptotic signals from each agent were used to drive cytotoxic effects of the combination. The final model captured plasma and intratumor PK data, apoptosis induction profiles, and tumor growth for all treatments/sequences. A feedback loop representing PAC-induced apoptosis effects on Kp_DXR enabled the model to capture tumor-priming effects. Simulations to explore time- and sequence-dependent effects of priming indicated that PAC priming increased Kp_DXR 3-fold. The intratumor concentrations producing maximal and half-maximal effects were 18 and 7.2 ?g/ml for PAC, and 17.6 and 14.3 ?g/ml for SSL-DXR. The duration of drug-induced apoptosis was 27.4 h for PAC and 15.8 h for SSL-DXR. Simulations suggested that PAC administered 24 h before peak priming could increase efficacy 2.5-fold over experimentally reported results. The quantitative approach developed in this article is applicable for evaluating tumor-priming strategies using diverse agents.

Straubinger, Robert M.; Mager, Donald E.

2013-01-01

154

Supramolecular Filaments Containing a Fixed 41% Paclitaxel Loading  

PubMed Central

We report here the self-assembly of a rationally designed paclitaxel drug amphiphile into well-defined supramolecular filaments that possess a fixed 41% paclitaxel loading. These filaments can exert effective cytotoxicity against a number of cell lines comparable to that of free paclitaxel.

Lin, Ran; Cheetham, Andrew G.; Zhang, Pengcheng; Lin, Yi-an

2013-01-01

155

In vitro cell cultures obtained from different explants of Corylus avellana produce Taxol and taxanes  

PubMed Central

Background Taxol is an effective antineoplastic agent, originally extracted from the bark of Taxus brevifolia with a low yield. Many attempts have been made to produce Taxol by chemical synthesis, semi-synthesis and plant tissue cultures. However, to date, the availability of this compound is not sufficient to satisfy the commercial requirements. The aim of the present work was to produce suspension cell cultures from plants not belonging to Taxus genus and to verify whether they produced Taxol and taxanes. For this purpose different explants of hazel (Corylus avellana species) were used to optimize the protocol for inducing in vitro callus, an undifferentiated tissue from which suspension cell cultures were established. Results Calli were successfully induced from stems, leaves and seeds grown in various hormone concentrations and combinations. The most suitable callus to establish suspension cell cultures was obtained from seeds. Media recovered from suspension cell cultures contained taxanes, and showed antiproliferative activity on human tumour cells. Taxol, 10-deacetyltaxol and 10-deacetylbaccatin III were the main taxanes identified. The level of Taxol recovered from the media of hazel cultures was similar to that found in yew cultures. Moreover, the production of taxanes in hazel cell cultures increased when elicitors were used. Conclusion Here we show that hazel cell cultures produce Taxol and taxanes under controlled conditions. This result suggests that hazel possesses the enzymes for Taxol production, which until now was considered to be a pathway particular to Taxus genus. The main benefit of producing taxanes through hazel cell cultures is that hazel is widely available, grows at a much faster rate in vivo, and is easier to cultivate in vitro than yew. In addition, the production of callus directly from hazel seeds shortens the culture time and minimizes the probability of contamination. Therefore, hazel could become a commercial source of Taxol and taxanes, both to be used as new therapeutic agents or as new precursors for Taxol semi-synthesis.

Bestoso, Federica; Ottaggio, Laura; Armirotti, Andrea; Balbi, Alessandro; Damonte, Gianluca; Degan, Paolo; Mazzei, Mauro; Cavalli, Francesca; Ledda, Bernardetta; Miele, Mariangela

2006-01-01

156

Molecular and biomolecular-based nanomaterials: Tubulin and taxol as molecular constituents  

NASA Astrophysics Data System (ADS)

The new field of protein-based nano-technology takes advantage of the complex interactions between proteins to form unique structures with properties that cannot be achieved with traditional components. Microtubules (MTs), self assembled proteinaceous hollow filaments, offer promise in the development of MT-based nano-systems. The compelling need for the controlled assembly of 3D MT arrays is the fundamental motivation for the first part of this research. We report on the morphology of MTs grown in a crowded environment in the form of high viscosity fluids containing agarose and a novel process that enables the assembly of MTs supported by gel-based 3D scaffolds. Our research on MTs and their interaction with other molecules lead us to discover extraordinary spherulitic structures that changed the course of the project. The novel subject situate us into a complicated dilemma that question the nature of MT asters reported in experiments carried out in cells. The second part of this research is focused in the crystallization of Taxol, a MT stabilizing molecule used as anti-cancer drug. It was confirmed via fluorescent and differential interference contrast microscopy that Taxol crystals can be decorated with fluorescent proteins and fluorochromes without perturbing their morphology. We used theoretical calculations to further investigate Taxol-fluorescent agent interactions. Furthermore, the crystallization of Taxol was studied in pure water, aqueous solutions containing tubulin proteins and tubulin-containing agarose gels. We demonstrated that tubulin is able to heterogeneously nucleate Taxol spherulites. To explain the formation of tubulin-Taxol nuclei a new, secondary Taxol-binding site within the tubulin heterodimer is suggested. Results presented in this work are important for in vivo and in vitro microtubule studies due to the possibility of mistaking these Taxol spherulites for microtubule asters. Thus, we are confirming the need for careful interpretation of fluorescence microscopy observations of MT structures when large concentrations of Taxol are used as stabilizing agent in cells.

Castro Carmona, Javier Servando

157

Paclitaxel-resistant Human Ovarian Cancer Cells Have Mutant b- Tubulins That Exhibit Impaired Paclitaxel-driven Polymerization  

Microsoft Academic Search

Acquired resistance to paclitaxel can be mediated by P-glycoprotein or by alterations involving tubulin. We report two paclitaxel-resistant sublines derived from 1A9 human ovarian carcinoma cells. Single-step pacli- taxel selection with verapamil yielded two clones that are resistant to paclitaxel and collaterally sensitive to vinblastine. The resistant sublines are not paclitaxel-de- pendent, and resistance remained stable after 3 years of

Paraskevi Giannakakou; Dan L. Sackett; Yoon-Koo Kang; Zhirong Zhan; Jeroen T. M. Buters; Tito Fojo; Marianne S. Poruchynsky

1997-01-01

158

Thermosensitive and biodegradable polymeric micelles for paclitaxel delivery.  

PubMed

The preparation, release and in vitro cytotoxicity of a novel polymeric micellar formulation of paclitaxel (PTX) were investigated. The micelles consisted of an AB block copolymer of poly(N-(2-hydroxypropyl) methacrylamide lactate) and poly(ethylene glycol) (pHPMAmDL-b-PEG). Taking advantage of the thermosensitivity of pHPMAmDL-b-PEG, the loading was done by simply mixing of a small volume of a concentrated PTX solution in ethanol and an aqueous polymer solution and subsequent heating of the resulting solution above the critical micelle temperature of the polymer. PTX could be almost quantitatively loaded in the micelles up to 2 mg/mL. By dynamic light scattering and cryo-transmission electron microscopy, it was shown that PTX-loaded micelles have a mean size around 60 nm with narrow size distribution. At pH 8.8 and 37 degrees C, PTX-loaded micelles destabilized within 10 h due to the hydrolysis of the lactic acid side group of the pHPMAmDL. Because the hydrolysis of the lactic acid side groups is first order in hydroxyl ion concentration, the micelles were stable for about 200 h at physiological conditions. The presence of serum proteins did not have an adverse effect on the stability of the micelles during at least 15 h. Interestingly, the dissolution kinetics of pHPMAmDL-b-PEG micelles was retarded by incorporation of PTX, indicating a strong interaction between PTX and the pHPMAmDL block. The PTX-loaded micelles showed a release of the incorporated 70% of PTX during 20 h at 37 degrees C and at pH 7.4. PTX-loaded pHPMAmDL-b-PEG micelles showed comparable in vitro cytotoxicity against B16F10 cells compared to the Taxol standard formulation containing Cremophor EL, while pHPMAmDL-b-PEG micelles without PTX were far less toxic than the Cremophor EL vehicle. Confocal laser-scanning microscopy (CLSM) and fluorescence activated cell sorting (FACS) analysis of fluorescently labelled micelles showed that pHPMAmDL-b-PEG micelles were internalized by the B16F10 cells. The present results suggest that pHPMAmDL-b-PEG block copolymer micelles are a promising delivery system for the parenteral administration of PTX. PMID:15763618

Soga, Osamu; van Nostrum, Cornelus F; Fens, Marcel; Rijcken, Cristianne J F; Schiffelers, Raymond M; Storm, Gert; Hennink, Wim E

2005-03-21

159

Oral microemulsions of paclitaxel: in situ and pharmacokinetic studies.  

PubMed

The overall goal of this study was to develop cremophor-free oral microemulsions of paclitaxel (PAC) to enhance its permeability and oral absorption. The mechanism of this enhancement, as well as characteristics of the microemulsions relevant to the increase in permeability and absorption of the low solubility, low permeability PAC was investigated. Phase diagrams were used to determine the macroscopic phase behavior of the microemulsions and to compare the efficiency of different surfactant-oil mixtures to incorporate water. The microemulsion region on the phase diagrams utilizing surfactant-myvacet oil combinations was in decreasing order: lecithin: butanol: myvacet oil (LBM, 48.5%)>centromix CPS: 1-butanol: myvacet oil (CPS, 45.15%)>capmul MCM: polysorbate 80: myvacet oil (CPM, 27.6%)>capryol 90: polysorbate 80: myvacet oil (CP-P80, 23.9%)>capmul: myvacet oil (CM, 20%). Oil-in-water (o/w) microemulsions had larger droplet sizes (687-1010 nm) than the water-in-oil (w/o) microemulsions (272-363 nm) when measured using a Zetasizer nano series particle size analyzer. Utilizing nuclear magnetic resonance spectroscopy (NMR), the self-diffusion coefficient (D) of PAC in CM, LBM and CPM containing 10% of deuterium oxide (D(2)O) was 2.24x10(-11), 1.97x10(-11) and 0.51x10(-11) m(2)/s, respectively. These values indicate the faster molecular mobility of PAC in the two w/o microemulsions (CM and LBM) than the o/w microemulsion--CPM. The in situ permeability of PAC through male CD-IGS rat intestine was 3- and 11-fold higher from LBM and CM, respectively, than that from the control clinical formulation, Taxol (CE, cremophor: ethanol) in a single pass perfusion study. PAC permeability was significantly increased in the presence of the pgp/CYP3A4 inhibitor cyclosporine A (CsA). This enhancement may be attributed to the pgp inhibitory effect of the surfactants, oil and/or the membrane perturbation effect of the surfactants. The oral disposition of PAC in CM, LBM and CPM compared to CE was studied in male CD-IGS rats after a single oral dose (20 mg/kg). The area-under-the-curve of PAC in CM was significantly larger than LBM, CPM and CE. Oral microemulsions of PAC were developed that increased both the permeability and AUC of PAC as compared to CE. PMID:18793723

Nornoo, Adwoa O; Zheng, Haian; Lopes, Luciana B; Johnson-Restrepo, Boris; Kannan, Kurunthachalam; Reed, Rachel

2009-02-01

160

Survivin deregulation in beta-tubulin mutant ovarian cancer cells underlies their compromised mitotic response to taxol.  

PubMed

Taxol is one of the most successful drugs for the treatment of cancer because of its ability to target tubulin, block cell cycle progression at mitosis, and induce apoptosis. Despite the success of Taxol, the development of drug resistance hampers its clinical applicability. Herein we report that beta-tubulin mutant, Taxol-resistant ovarian cancer cells exhibit defective mitotic response to Taxol, even at high concentrations that are sufficient to trigger apoptosis. This mitotic response-defective phenotype is independent of p53 status. We have found that survivin, the mitosis regulator and inhibitor of apoptosis protein, is deregulated in these Taxol-resistant cancer cells; Taxol fails to induce survivin levels and survivin phosphorylation in these cells, in contrast to their parental drug-sensitive counterparts. Exogenous expression of wild-type survivin is able to restore the mitotic response of the resistant cells to Taxol treatment. On the other hand, exogenous expression of dominant-negative survivin abrogates the Taxol-induced mitotic response in drug-sensitive cancer cells. We have also found that overexpression of the mitotic kinase Cdk1, which phosphorylates survivin, is unable to restore the Taxol-induced mitotic response in the resistant cells. Our results show the importance of survivin for the mitotic response in the context of Taxol resistance and provide novel insights into the mechanisms of mitotic arrest and apoptosis induced by microtubule-targeting agents. PMID:15574781

Zhou, Jun; O'brate, Aurora; Zelnak, Amelia; Giannakakou, Paraskevi

2004-12-01

161

Thermosensitive micelles-hydrogel hybrid system based on poloxamer 407 for localized delivery of paclitaxel.  

PubMed

A thermosensitive micelles-hydrogel hybrid system based on Poloxamer 407 (P407) was prepared to resolve the fast erosion and low loading capability of lipophilic drug of P407 gels for local chemotherapy. Different amounts of glutaraldehyde (GA) were applied to generate cross-linked networks with carboxymethyl chitosan (CMCS) interpenetrated in P407 gels, in which paclitaxel (PTX)-loaded N-octyl-O-sulfate chitosan micelles (PTX-M) were dispersed uniformly. The in vitro characteristics of CMCS-modified P407 gels (PTX-M-MG) were performed by examining the viscosity, swelling ratio, mechanical property, and drug release, while the in vivo evaluation included tissue distribution and anticancer efficacy through intratumoral administration in hepatoma solidity cell (Heps) tumor-bearing mice. The results showed that PTX-M-MG containing 0.05% (w/v) GA possessed lower viscosity, higher swelling ratio, stronger mechanical property, and longer term drug release, in which the loading efficiency of PTX was enlarged by the introduction of PTX-M. Moreover, PTX-M-MG revealed a prolonged retention at tumor sites, lasting for 20 days, and a superior tumor inhibition rate (64.27%) with reduced toxicity compared with Taxol(®) , PTX-M, and PTX-M loaded unmodified P407 gels (PTX-M-P407). It can be concluded that PTX-M-MG is a promising local delivery system for hydrophobic drug in cancer therapy, providing both improved efficacy and relieved side effects. PMID:23839931

Ju, Caoyun; Sun, Juan; Zi, Peng; Jin, Xiang; Zhang, Can

2013-08-01

162

Lipid nanocarriers improve paclitaxel transport throughout human intestinal epithelial cells by using vesicle-mediated transcytosis.  

PubMed

The use of lipid nanocapsules (LNCs) has enabled an improvement of the oral bioavailability of paclitaxel (Ptx). However, mechanisms that support this recent observation are not yet understood. By focusing on the well defined in vitro Caco-2 model, the purpose of this study was to evaluate the transport of LNCs across a model intestinal barrier. Firstly, four sizes of paclitaxel or dye (Nile Red)-loaded LNCs were formulated and LNCs with sizes between 26.3+/-2.7 nm and 132.7+/-5.5 nm were obtained. Different transport and uptake experiments were then performed across a Caco-2 cells culture model using these LNCs. Paclitaxel-loaded LNCs improved permeability of Ptx across intestinal epithelium compared with free Ptx or Taxol by a factor of 3.5. At 37 degrees C particle size did not influence transport efficiency. However, at 4 degrees C a decrease in Ptx transport was observed with increasing size of LNCs. Thus, with LNCs of 25 nm size, the apparent permeability coefficient (P(app)) was 5.3+/-1.1 cm s(-1) at 37 degrees C and 2.2+/-0.4 cm s(-1) at 4 degrees C. In comparison in LNCs of 130 nm size, the P(app) decreased from 5.8+/-0.8 cm s(-1) at 37 degrees C to 0.5+/-0.1 cm s(-1) at 4 degrees C. The uptake of LNCs by Caco-2 cells and the incapacity of LNCs to open tight junctions were also demonstrated. Furthermore, experiment transports were performed in the presence of different inhibitors of endocytosis. Findings indicated a reduction of Ptx transport of 30+/-6% when cell cholesterol was depleted, 65+/-12% when caveolae-mediated endocytosis was inhibited and 20+/-8% when clathrin-mediated endocytosis was inhibited. Finally, transmission electronic microscopy showed the presence of nano-objects on the basolateral side of the Caco-2 cell monolayers when LNCs were applied on the apical side. PMID:19699246

Roger, E; Lagarce, F; Garcion, E; Benoit, J-P

2009-12-01

163

Taxol inhibits stretch-induced electrophysiological alterations in isolated rat hearts with acute myocardial infarction.  

PubMed

Mechanosensitive channels have been determined to work as transducers of mechanoelectric feedback in the heart, which is associated with the generation of arrhythmias. Recent studies have investigated the role of the cytoskeleton in ion channels control. This study explored the ability of taxol to inhibit stretch-induced electrophysiological alterations in the ischemic myocardium. Thirty-two Wistar rats were randomly divided into four groups: normal control group (n=9), taxol group (n=7), myocardial infarction (MI) group (n=9), and MI+taxol group (n=7). After Langendorff perfusion, the isolated hearts were stretched for 5 s by balloon inflation to 0.2 or 0.3 mL. The effects of stretching on 90% monophasic action potential duration (MAPD(90)), premature ventricular beats (PVB), and ventricular tachycardia (VT) were observed for 30 s. Stretching increased MAPD(90) in both the normal control and MI groups, but MAPD(90) increased more in the MI group for the same degree of stretch. Taxol (5 mumol L(-1)) had no effect on MAPD(90) under baseline, unstretched conditions, but MAPD(90) in the taxol group was slightly increased after stretching compared with the normal control group (P>0.05). However, taxol reduced MAPD(90) in infarcted myocardium (P<0.05 at DeltaV=0.3 mL). The incidences of PVB and VT in the MI group were higher than in the normal control group (both P<0.01). Taxol had no effect on the occurrence of arrhythmias in normal myocardium, but it inhibited PVB and VT in infarcted hearts (both P<0.01). Thus changes in MAPD and the occurrence of arrhythmias caused by mechanical stretching of the myocardium could be inhibited by taxol in isolated rat hearts during AMI, indicating the involvement of tubulin in mechanoelectric feedback in AMI. PMID:20821300

Cao, JunXian; Fu, Lu; Sun, DianJun; Xie, RongSheng; Zhou, Jue; Qu, Fan

2010-08-01

164

Taxol induces paraptosis independent of both protein synthesis and MAPK pathway.  

PubMed

Our recent studies have shown that high concentration of taxol induced a caspase-independent paraptosis-like cell death and cytoplasmic vacuolization derived predominantly from endoplasmic reticulum (ER) swelling in human lung carcinoma cell lines (ASTC-a-1). In this report, we further explored the relationship between taxol-induced cell death and vacuolization, and the roles of protein synthesis, mitogen-activated protein kinase kinases (MEK), c-jun N-terminal kinase (JNK) and P38 in taxol-induced paraptosis. Enhanced green fluorescent protein (EGFP) was used to probe the cell morphological change, while ER-targeted red fluorescent protein (er-RFP) was used to probe ER spatial distribution. Real-time monitoring of the ER swelling dynamics during the formation of vacuolization inside single living cells co-expressing EGFP and er-RFP further demonstrated that taxol-induced cytoplasmic vacuolization was from the ER restructuring due to fusion and swelling. PI staining showed that taxol-induced vacuolization was not necrosis. These results further demonstrated that the taxol-induced cell death was neither apoptosis nor necrosis, and fitted the criteria of paraptosis characterized by cytoplasmic vacuolization, caspase-independence, lack of apoptotic morphology and insensitivity to broad caspase inhibitor. Our data further indicated that taxol-induced paraptosis required neither protein synthesis nor the participation of MEK, JNK, and P38, which was different from the insulin-like growth factor I receptor (IGFIR)-induced paraptosis. These results suggest that high concentration of taxol activates an alternative paraptotic cell death pathway. PMID:19918793

Sun, Qingrui; Chen, Tongsheng; Wang, Xiaoping; Wei, Xunbin

2010-02-01

165

Expression of the anti-apoptotic gene survivin correlates with taxol resistance in human ovarian cancer  

Microsoft Academic Search

Stable transfection of human ovarian carci- noma cells with survivin cDNA caused a four- to sixfold increase in cell resistance to taxotere and taxol (two-sided Student's t test, p < 0.05), with a concomitant reduction in the apoptotic response to taxol, but did not affect cell sen- sitivity to cisplatin or oxaliplatin. Such findings were in- directly supported by similar

N. Zaffaroni; M. Pennati; G. Colella; P. Perego; R. Supino; L. Gatti; S. Pilotti; F. Zunino; M. G. Daidone

2002-01-01

166

Alteration of Lymphocyte Microtubule Assembly, Cytotoxicity, and Activation by the Anticancer Drug Taxol1  

Microsoft Academic Search

We studied the effect of the anticancer drug taxol on the cytotoxic mechanism of major histocompatibility complex nonrestricted lympho cytes and their activation with interleukin 2. Unseparated lymphocytes or highly enriched natural killer or T-cells were treated with 0.2-10 ¿tg\\/ml of taxol for various times and tested for cytotoxicity against the K562 cell line and the ovarian cell line, OV-2774.

Linus T. Chuang; Julian Heath; Kenton R. Cook; Adnan Munkarah; Mitchell Morris; J. Taylor Wharton

167

Enhancement of esculetin on Taxol-induced apoptosis in human hepatoma HepG2 cells  

SciTech Connect

The potential use of low dose chemotherapy has been appealing since lower dosages are more attainable during cancer therapy and cause less toxicity in patients. Combination therapy of Taxol, a promising frontline chemotherapy agent, with natural anti-tumor agents that are considerably less toxic with a capability of activating additional apoptotic signals or inhibiting survival signals may provide a rational molecular basis for novel chemotherapeutic strategies. Esculetin, a well-known lipoxygenase inhibitor, showed an inhibitory effect on the cell cycle progression of HL-60 cells in our previous study. In this report, the effects of a concomitant administration of esculetin and Taxol were investigated in human hepatoma HepG2 cells. Firstly, esculetin alone could exert an antiproliferation effect together with an inhibitory effect on the activation of ERKs and p38 MAPK. As compared to the treatment with Taxol only, a co-administration with esculetin and Taxol could result in a further enhancement of apoptosis as revealed by DNA fragmentation assay and Annexin-V-based assay. Meanwhile, immunoblotting analysis also showed that the co-administration of esculetin and Taxol could increase the expression of Bax and the cytosolic release of cytochrome C and enhance the expression of Fas and Fas ligand while the activation of caspase-8 and caspase-3 was also increased. Finally, the ERK cascade was proven to be involved in the enhancement of esculetin on the Taxol-induced apoptosis.

Kuo, H.-C. [Institute of Biochemistry and Biotechnology, Chung Shan Medical University, Chien Kuo N. Road, Taichung 402, Taiwan (China); Lee, H.-J. [Institute of Biochemistry and Biotechnology, Chung Shan Medical University, Chien Kuo N. Road, Taichung 402, Taiwan (China); Hu, C.-C. [School of Applied Chemistry, Chung Shan Medical University, No. 110, Section 1, Chien Kuo N. Road, Taichung 402, Taiwan (China); Shun, H.-I [Institute of Biochemistry and Biotechnology, Chung Shan Medical University, Chien Kuo N. Road, Taichung 402, Taiwan (China); Tseng, T.-H. [School of Applied Chemistry, Chung Shan Medical University, No. 110, Section 1, Chien Kuo N. Road, Taichung 402, Taiwan (China)]. E-mail: tht@csmu.edu.tw

2006-01-15

168

Abundant expression of the microtubule-associated protein, ensconsin (E-MAP-115), alters the cellular response to Taxol  

Microsoft Academic Search

Correlation between expression level of a microtubule-associated protein called ens- consin (E-MAP-115) and degree of Taxol sensitivity in several cultured cell lines prompted us to investigate potential cause-and-effect relationships between ensconsin level and Taxol action. We used human MCF-7 or HeLa cells, which are sensitive to low Taxol concentrations (LD50 of 30 -35 and 3.5 nM, respectively) to prepare stably

Dorota Gruber; Kathleen Faire

2001-01-01

169

Taxol-induced mitotic block triggers rapid onset of a p53-independent apoptotic pathway.  

PubMed Central

BACKGROUND: At therapeutic concentrations, the antineoplastic agent taxol selectively perturbs mitotic spindle microtubules. Taxol has recently been shown to induce apoptosis, similar to the mechanism of cell death induced by other antineoplastic agents. However, taxol has shown efficacy against drug-refractory cancers, raising the possibility that this pharmacological agent may trigger an alternative apoptotic pathway. MATERIALS AND METHODS: The kinetics and IC50 of mitotic (M) block, aberrant mitosis, and cytotoxicity following taxol treatment were analyzed in human cell lines as well as normal mouse embryo fibroblasts (MEFs) and MEFs derived from p53-null mice. Apoptosis was followed by DNA gel electrophoresis and by in situ DNA end-labeling (TUNEL). RESULTS: Taxol induced two forms of cell cycle arrest: either directly in early M at prophase or, for those cells progressing through aberrant mitosis, arrest in G1 as multimininucleated cells. TUNEL labeling revealed that DNA nicking occurred within 30 min of the arrest in prophase. In contrast, G1-arrested, multimininucleated cells became TUNEL positive only after several days. In the subset of cells that became blocked directly in prophase, both wt p53-expressing and p53-null MEFs responded similarly to taxol, showing rapid onset of DNA nicking and apoptosis. However, p53-null MEFs progressing through aberrant mitosis failed to arrest in the subsequent G1 phase or to become TUNEL positive, and remained viable. CONCLUSIONS: Taxol induces two forms of cell cycle arrest, which in turn induce two independent apoptotic pathways. Arrest in prophase induces rapid onset of a p53-independent pathway, whereas G1-block and the resulting slow (3-5 days) apoptotic pathway are p53 dependent. Images FIG. 2 FIG. 3 FIG. 4 FIG. 5 FIG. 8 FIG. 9 FIG. 11

Woods, C. M.; Zhu, J.; McQueney, P. A.; Bollag, D.; Lazarides, E.

1995-01-01

170

Taxol and Taurine Protect the Renal Tissue of Rats after Unilateral Ureteral Obstruction: A Stereological Survey  

PubMed Central

Purpose Blockage of the urinary tract induces changes in renal structure including tubular dilatation or atrophy, tubular cell death, inflammatory processes, and progressive interstitial fibrosis with the loss of renal parenchyma. The present study was conducted to survey the protective effects of Taxol and taurine on the renal structure after unilateral ureteral obstruction (UUO). Materials and Methods UUO was induced in three groups of rats (n=6) who then received distilled water, Taxol (0.3 mg/kg/d), or taurine (7.5 mg/kg/d). Stereological methods were used to gather quantitative as well as comparative data. Results Less than -8% of the volume of the glomeruli, proximal convoluted tubules (PCT), distal convoluted tubules (DCT), Henle's loop, and collecting ducts were preserved after UUO. After treatment of the UUO rats with Taxol, between -32% and 88% of the parameters mentioned above remained intact, and after treatment of the UUO rats with taurine, between -16% and 46% of the parameters remained intact (p<0.01). Compared with the untreated UUO animals, the volume of necrotic and fibrotic tissues decreased -53% and -63% in the UUO rats treated with Taxol and taurine, respectively (p<0.01). Less than -3% of the lengths of the renal tubules (PCT, DCT, Henle's loop, and collecting) were preserved in the UUO rats. After treatment with Taxol and taurine, -61% to 70% and -43% to 53% of the length of the renal tubules were preserved, respectively (p<0.01). Conclusions Taurine and Taxol are effective in preventing some structural renal damage in a direct ureteral obstruction model. Taxol was more effective in renal protection.

Karbalay-Doust, Saied; Pourshahid, Seyed-Mohammad

2012-01-01

171

Insulin-Like Growth Factor 2 Silencing Restores Taxol Sensitivity in Drug Resistant Ovarian Cancer  

PubMed Central

Drug resistance is an obstacle to the effective treatment of ovarian cancer. We and others have shown that the insulin-like growth factor (IGF) signaling pathway is a novel potential target to overcome drug resistance. The purpose of this study was to validate IGF2 as a potential therapeutic target in drug resistant ovarian cancer and to determine the efficacy of targeting IGF2 in vivo. An analysis of The Cancer Genome Atlas (TCGA) data in the serous ovarian cancer cohort showed that high IGF2 mRNA expression is significantly associated with shortened interval to disease progression and death, clinical indicators of drug resistance. In a genetically diverse panel of ovarian cancer cell lines, the IGF2 mRNA levels measured in cell lines resistant to various microtubule-stabilizing agents including Taxol were found to be significantly elevated compared to the drug sensitive cell lines. The effect of IGF2 knockdown on Taxol resistance was investigated in vitro and in vivo. Transient IGF2 knockdown significantly sensitized drug resistant cells to Taxol treatment. A Taxol-resistant ovarian cancer xenograft model, developed from HEY-T30 cells, exhibited extreme drug resistance, wherein the maximal tolerated dose of Taxol did not delay tumor growth in mice. Blocking the IGF1R (a transmembrane receptor that transmits signals from IGF1 and IGF2) using a monoclonal antibody did not alter the response to Taxol. However, stable IGF2 knockdown using short-hairpin RNA in HEY-T30 effectively restored Taxol sensitivity. These findings validate IGF2 as a potential therapeutic target in drug resistant ovarian cancer and show that directly targeting IGF2 may be a preferable strategy compared with targeting IGF1R alone.

Brouwer-Visser, Jurriaan; Lee, Jiyeon; McCullagh, KellyAnne; Cossio, Maria J.; Wang, Yanhua; Huang, Gloria S.

2014-01-01

172

Evaluation of neurotoxicity induced by paclitaxel second-line chemotherapy  

Microsoft Academic Search

The most important cytotoxic drugs for the treatment of ovarian cancer, platinum compounds and paclitaxel, are known to induce\\u000a neurotoxicity, which is dose limiting when higher paclitaxel doses are used or platinum-pretreated patients are treated. The\\u000a absolute dose of paclitaxel per course has been demonstrated to be an important risk factor for the development of neurotoxicity.\\u000a The role of cumulative

Andreas du Bois; Markus Schlaich; Hans-Joachim Lück; Anne Mollenkopf; Ulrike Wechsel; Matthea Rauchholz; Thomas Bauknecht; Hans-Gerd Meerpohl

1999-01-01

173

EGFR-Specific Single-Chain Antibody-Taxol Conjugate for Radiosensitizing Breast Carcinomas.  

National Technical Information Service (NTIS)

We propose to conjugate paclitaxel to a single-chain antibody that specifically binds to the extracellular domain of the EGFR. The scFv-paclitaxel conjugate will be able to localize to the tumor rapidly, penetrate deeper, be eliminated quickly, and induce...

K. P. Raisch

2001-01-01

174

Ion specific effects in bundling and depolymerization of taxol-stabilized microtubules  

PubMed Central

Microtubules (MTs) are nanometer scale hollow cylindrical biological polyelectrolytes. They are assembled from ?/?-tubulin dimers, which stack to form protofilaments (PFs) with lateral interactions between PFs resulting in the curved MT. In cells, MTs and their assemblies are critical components in a range of functions from providing tracks for the transport of cargo to forming the spindle structure during mitosis. Previous studies have shown that while cations with valence equal to or larger than 3+ tend to assemble tight 3D bundles of taxol-stabilized MTs, certain divalent cations induce relatively loose 2D bundles of different symmetry [D. J. Needleman, et al., PNAS, 2004, 101, 16099]. Similarly, divalent cations form 2D bundles of DNA adsorbed on cationic membranes [I. Koltover, et al., PNAS, 2000, 97, 14046]. The bundling behavior for these biological polyelectrolyte systems is qualitatively in agreement with current theory. Here, we present results, which show that unlike the case for DNA adsorbed on cationic membranes, bundling of taxol-stabilized MTs occurs only for certain divalent cations above a critical ion concentration (e.g. Ca2+, Sr2+, Ba2+). Instead many divalent cations preempt the bundling transition and depolymerize taxol-stabilized MTs at a lower counterion concentration. Although previous cryogenic TEM has shown that, in the absence of taxol, Ca2+ depolymerizes MTs assembling in buffers containing GTP (guanosine triphosphate), our finding is surprising given the known stabilizing effects of taxol on GDP (guanosine diphosphate)-MTs. The ion concentration required for MT depolymerization decreases with increasing atomic number for the divalents Mg2+, Mn2+, Co2+, and Zn2+. GdCl3 (3+) is found to be extremely efficient at MT depolymerization requiring about 1 mM, while oligolysine (2+), is observed not to depolymerize MTs at concentrations as high as 144 mM. The surprising MT depolymerization results are discussed in the context of divalents disrupting either lateral interactions between PFs (which are strengthened for taxol containing ?-tubulin) or interfering with taxol’s ability to induce flexibility at the interface between two tubulin dimers in the same PF (which has been recently suggested as a mechanism by which taxol stabilizes MTs post-hydrolysis with the induced flexibility counteracting the kink between GDP-tubulin dimers in a PF).

Needleman, Daniel J.; Ojeda-Lopez, Miguel A.; Raviv, Uri; Miller, Herbert P.; Li, Youli; Song, Chaeyeon; Feinstein, Stuart C.; Wilson, Leslie; Choi, Myung Chul

2013-01-01

175

Biological and ultrastructural effects of the anti-microtubule agent taxol against Trypanosoma cruzi.  

PubMed

Microtubules play fundamental roles in eukaryotic cells and have been investigated as target for drugs. Several studies showed the potential use of anti-microtubule agents against pathogenic protozoa. Taxol has been intensively studied in Leishmania spp. and microtubules have been considered as a promising antileishmanial drug target. It has been also shown that taxol interferes with the proliferation of Trypanosoma cruzi, leading to morphological alterations and interruption of nuclear division and cytokinesis. In the present work we show that T. cruzi bloodstream trypomastigotes were much more susceptible than epimastigotes, and in both forms taxol caused severe ultrastructural damage, especially associated to changes in the shape of the parasites. In trypomastigotes, different degrees of body contortion along the longitudinal axis and a marked dilatation of the flagellar pocket were detected. Treated epimastigotes presented a decrease in the electron density of the mitochondrial matrix, absence of mitochondrial cristae and an increase in the number of lipid droplets. Bizarre multi-flagellar epimastigotes were also detected, suggesting an interruption of the cytokinesis. Taxol caused no noticeable ultrastructural alterations on sub-pellicular and flagellar microtubules of both evolutive forms of T. cruzi. As already described in the literature, such structures in trypanosomatids are very resistant to microtubule disrupters when compared to those in mammalian cells. Taxol prevented the endocytosis of albumin-gold complexes by epimastigotes, and this result could be associated to the loss of the dynamic stability of the microtubules of the cytostome. PMID:14690177

Dantas, A P; Barbosa, H S; De Castro, S L

2003-07-01

176

Supramolecular micellar nanoaggregates based on a novel chitosan/vitamin E succinate copolymer for paclitaxel selective delivery  

PubMed Central

Background Nowadays, many cytotoxic anticancer drugs exhibit low solubility and poor tumor selectivity, which means that the drug formulation is very important. For example, in the case of paclitaxel (PTX), Cremophor EL® (BASF, Ludwigshafen, Germany) needs to be used as a solubilizer in its clinical formulation (Taxol®, Bristol-Myers Squibb, New York, NY), although it can cause serious side effects. Nanomicellar systems are promising carriers to resolve the above problems, and the polymer chosen is the key element. Methods In this study, a novel amphiphilic chitosan/vitamin E succinate (CS-VES) copolymer was successfully synthesized for self-assembling polymeric micelles. Proton nuclear magnetic resonance spectroscopy and infrared were used to characterize the molecular structure of the copolymer. The PTX-loaded CS-VES polymeric micelles (PTX-micelles) were characterized by dynamic light scattering, transmission electron microscopy, X-ray diffraction, and differential scanning calorimetry. Results The critical micelle concentration of CS-VES was about 12.6 ?g/mL, with the degree of amino group substitution being 20.4%. PTX-micelles were prepared by a nanoprecipitation/dispersion technique without any surfactant being involved. PTX-micelles exhibited a drug loading as high as 21.37% and an encapsulation efficiency of 81.12%, with a particle size ranging from 326.3 to 380.8 nm and a zeta potential of +20 mV. In vitro release study showed a near zero-order sustained release, with 51.06%, 50.88%, and 44.35% of the PTX in the micelles being released up to 168 hours at three drug loadings of 7.52%, 14.09%, and 21.37%, respectively. The cellular uptake experiments, conducted by confocal laser scanning microscopy, showed an enhanced cellular uptake efficiency of the CS-VES micelles in MCF-7 cells compared with Taxol. The PTX-micelles exhibited a comparable but delayed cytotoxic effect compared with Taxol against MCF-7 cells, due to the sustained-release characteristics of the nanomicelles. More interestingly, blank nanomicelles based on CS-VES copolymer demonstrated significant cytotoxicity against MCF-7 cells. Conclusion The supramolecular micellar aggregates based on CS-VES copolymer is a promising nanocarrier and efficacy enhancer when used as an anticancer drug-delivery system.

Lian, He; Sun, Jin; Yu, Yan Ping; Liu, Yan Hua; Cao, Wen; Wang, Yong Jun; Sun, Ying Hua; Wang, Si Ling; He, Zhong Gui

2011-01-01

177

The mechanism of enhancement on oral absorption of paclitaxel by N-octyl-O-sulfate chitosan micelles.  

PubMed

The overall objective of the present investigation was to demonstrate the effect of N-octyl-O-sulfate chitosan (NOSC) micelles on enhancing the oral absorption of paclitaxel (PTX) in vivo and in vitro, and identify the mechanism of this action of NOSC. In vivo, the oral bioavailability of PTX loaded in NOSC micelles (PTX-M) was 6-fold improved in comparison with that of an orally dosed Taxol(®). In the Caco-2 uptake studies, NOSC micelles brought about a significantly higher amount of PTX accumulated in Caco-2 cells via both clathrin- and caveolae-mediated endocytosis, and NOSC had the effect on inhibiting PTX secreted by P-glycoprotein (P-gp), which was also proved by the studies on rhodamine 123 incorporated in NOSC micelles, fluorescence labeled micelles. The mechanism of NOSC on P-gp inhibition was demonstrated in connection with interfering the P-gp ATPase by NOSC rather than reducing the P-gp expression. Moreover, NOSC with the concentration approaching the critical micellar concentration (CMC) had the strongest effect on P-gp inhibition. In the Caco-2 transport studies, the presence of verapamil and NOSC both improved the transport of Taxol(®), which further certified the effect of NOSC on P-gp inhibition, and PTX-M enhanced the permeability of PTX compared with Taxol(®). The apparent permeability coefficient (Papp) of PTX-M decreased significantly at 4 °C in comparison with at 37 °C, which indicated a predominant active endocytic mechanism for the transport of PTX-M, a P-gp-independent way. Furthermore, the transcytosis of PTX-M was via clathrin-mediated rather than caveolae-mediated. In addition, the transepithelial electrical resistance (TEER) of Caco-2 cell monolayers had no significant change during the transport study, which pointed out that NOSC had no effect on opening the intercellular tight junctions. Based on the obtained results, it is suggested that NOSC micelles might be a potentially applicable tool for enhancing the oral absorption of P-gp substrates. PMID:21440934

Mo, Ran; Jin, Xiang; Li, Nan; Ju, Caoyun; Sun, Minjie; Zhang, Can; Ping, Qineng

2011-07-01

178

Fabrication of monodispersed Taxol-loaded particles using electrohydrodynamic atomization.  

PubMed

In the fabrication of controlled drug release matrix, monodispersed particle sizes are usually preferred as they give a more uniform and precisely controlled release profile. Electrohydrodynamic atomization (EHDA) [J.C. Ijsebaert, K.B. Geerse, J.C.M. Marijnissen, J.W.J Lammers, P. Zannen, Electro-Hydrodynamic atomization of drug solutions for inhalation purposes, J. Appl. Physiol. 91(2001), 2735-2741.] is a method that can potentially produce particles with very low polydispersity. In the present work, Taxol-loaded poly-caprolactone (PCL) particles were fabricated using EHDA. Effort was undertaken to investigate the cause of the low yield of EHDA and to improve it to around 80%. This was achieved by increasing the ventilation and properly discharging the residual charges on the particulate cake at the filter paper. A phase Doppler particle analyzer (PDPA) was used to detect the spray modes of EHDA and the optimum operating conditions were determined. With differential scanning calorimetry (DSC), the uniformity of drug and polymer matrix is investigated. Moderate zeta potential values together with laser confocal micrographs give a possible explanation for the in vitro cell uptake data. These results are substantiated by a reasonably high encapsulation efficiency (EE) and sustained release profiles over 1-month period. The EHDA method is shown to be a potentially suitable technique to prepare close to monodispersed drug release particles. PMID:15653160

Ding, Luna; Lee, Timothy; Wang, Chi-Hwa

2005-02-01

179

Economic considerations in cooperative research and development agreements (CRADA): The case of Taxol, NIH, and technology transfer  

Microsoft Academic Search

The General Accounting Office (GAO) of the U.S. Congress released a 2003 report examining the legal and financial issues by the National Institutes of Health (NIH) in the technology transfer of Taxol, a cancer treatment drug, which was commercialized quickly by Bristol-Myers Squibb (BMS). The GAO concludes that the 1991 cooperative research and development agreement (CRADA) transferring Taxol to the

Thomas A. Hemphill

2006-01-01

180

Effect of phenylalanine on Taxol production and antioxidant activity of extracts of suspension-cultured hazel (Corylus avellana L.) cells.  

PubMed

Taxol is produced by a few microorganisms and plants such as yew (Taxus sp.). Recent researches have shown that hazel (Corylus avellana L.) is also able to produce Taxol. In the present study, effects of different concentrations of phenylalanine (Phe) on the production of Taxol, antioxidant activity, and cytotoxic effects of extracts of suspension-cultured hazel cells were investigated. The cells were treated with different concentrations of Phe on day 7 of subculture and were harvested on day 14. The results showed that the amounts of Taxol and antioxidant activity were increased by increasing the phenylalanine supply. Interestingly, the cytotoxic effects of hazel cell extract were even stronger than that of pure Taxol (standard), suggesting hazel cell extract as a novel and suitable probe for treating human cancer. Application of phenylalanine to hazel cells exaggerates their effects. PMID:22847380

Bemani, Ebrahim; Ghanati, Faezeh; Rezaei, Ayatollah; Jamshidi, Mitra

2013-07-01

181

Expression of paclitaxel-inactivating CYP3A activity in human colorectal cancer: implications for drug therapy  

PubMed Central

Cytochrome P450 3A is a drug-metabolising enzyme activity due to CYP3A4 and CYP3A5 gene products, that is involved in the inactivation of anticancer drugs. This study analyses the potential of cytochrome P450 3A enzyme in human colorectal cancer to impact anticancer therapy with drugs that are cytochrome P450 3A substrates. Enzyme activity, variability and properties, and the ability to inactivate paclitaxel (taxol) were analysed in human colorectal cancer and healthy colorectal epithelium. Cytochrome P450 3A enzyme activity is present in healthy and tumoral samples, with a nearly 10-fold interindividual variability. Nifedipine oxidation activity±s.d. for colorectal cancer microsomes was 67.8±36.6?pmol min?1?mg?1. The Km of the tumoral enzyme (42±8??M) is similar to that in healthy colorectal epithelium (36±8??M) and the human liver enzyme. Colorectal cancer microsomes metabolised the anticancer drug paclitaxel with a mean activity was 3.1±1.2?pmol?min?1?mg?1. The main metabolic pathway is carried out by cytochrome P450 3A, and it is inhibited by the cytochrome P450 3A-specific inhibitor ketoconazole with a KI value of 31?nM. This study demonstrates the occurrence of cytochrome P450 3A-dependent metabolism in colorectal cancer tissue. The metabolic activity confers to cancer cells the ability to inactivate cytochrome P450 3A substrates and may modulate tumour sensitivity to anticancer drugs. British Journal of Cancer (2002) 87, 681–686. doi:10.1038/sj.bjc.6600494 www.bjcancer.com © 2002 Cancer Research UK

Martinez, C; Garcia-Martin, E; Pizarro, R M; Garcia-Gamito, F J; Agundez, J A G

2002-01-01

182

Reduced effect of taxol on plasma protein secretion by developing rat liver.  

PubMed

The effect of taxol, a potent stabilizer of microtubules, on plasma protein secretion by slices prepared from mature and developing rat liver was determined. After 4 hr of incubation, taxol (50 microM) inhibited albumin secretion by only 10% on gestation Day 19, by 16% 4 days after birth, but by 40% in the adult. Inhibition of glycoprotein secretion by taxol was similar to that of albumin secretion at all ages studied. Combined with information obtained from previous investigations, the present study indicates that agents that either inhibit microtubular assembly or that stabilize microtubules both have a reduced capacity to inhibit hepatic protein secretion during development. These findings suggest that a reduced requirement for microtubular participation in protein secretion is present in developing liver. PMID:2868546

Kaufman, S S; Tuma, D J; Vanderhoof, J A

1986-02-01

183

Distinct Pose of Discodermolide in Taxol Binding Pocket Drives a Complementary Mode of Microtubule Stabilization  

PubMed Central

The microtubule cytoskeleton has proven to be an effective target for cancer therapeutics. One class of drugs, known as microtubule stabilizing agents (MSAs), binds to microtubule polymers and stabilizes them against depolymerization. The prototype of this group of drugs, Taxol, is an effective chemotherapeutic agent used extensively in the treatment of human ovarian, breast, and lung carcinomas. Although electron crystallography and photoaffinity labeling experiments determined that the binding site for Taxol is in a hydrophobic pocket in ?-tubulin, little was known about the effects of this drug on the conformation of the entire microtubule. A recent study from our laboratory utilizing hydrogen-deuterium exchange (HDX) in concert with various mass spectrometry (MS) techniques has provided new information on the structure of microtubules upon Taxol binding. In the current study we apply this technique to determine the binding mode and the conformational effects on chicken erythrocyte tubulin (CET) of another MSA, discodermolide, whose synthetic analogues may have potential use in the clinic. We confirmed that like Taxol, discodermolide binds to the taxane binding pocket in ?-tubulin. However, as opposed to Taxol, which has major interactions with the M-loop, discodermolide orients itself away from this loop and towards the N-terminal H1–S2 loop. Additionally, discodermolide stabilizes microtubules mainly via its effects on interdimer contacts, specifically on the ?-tubulin side, and to a lesser extent on interprotofilament contacts between adjacent ?-tubulin subunits. Also, our results indicate complementary stabilizing effects of Taxol and discodermolide on the microtubules, which may explain the synergy observed between the two drugs in vivo.

Khrapunovich-Baine, Marina; Menon, Vilas; Verdier-Pinard, Pascal; Smith, Amos B.; Angeletti, Ruth Hogue; Fiser, Andras; Horwitz, Susan Band; Xiao, Hui

2010-01-01

184

Possible Side Effects of Carboplatin, 5-Fluorouracil, and Paclitaxel  

Cancer.gov

Page of 1Possible Side Effects of Carboplatin, 5-Fluorouracil, and Paclitaxel (Table Version Date: October 8, 2013) COMMON, SOME MAY BE SERIOUS In 100 people receiving Carboplatin, 5-Fluorouracil, and Paclitaxel, more than 20 and up to 100 may have: Hair

185

Possible Side Effects of Cisplatin, 5-Fluorouracil, and Paclitaxel  

Cancer.gov

Page of 1Possible Side Effects of Cisplatin, 5-Fluorouracil, and Paclitaxel (Table Version Date: October 8, 2013) COMMON, SOME MAY BE SERIOUS In 100 people receiving Cisplatin, 5-Fluorouracil, and Paclitaxel, more than 20 and up to 100 may have: Diarrhea,

186

Possible Side Effects of 5-Fluorouracil, Oxaliplatin, Paclitaxel  

Cancer.gov

Page of 2Possible Side Effects of 5-Fluorouracil, Oxaliplatin, Paclitaxel (Table Version Date: October 8, 2013) COMMON, SOME MAY BE SERIOUS In 100 people receiving 5-Fluorouracil, Oxaliplatin, Paclitaxel, more than 20 and up to 100 may have: Hair loss Redness,

187

Erythropoietin protects sensory axons against paclitaxel-induced distal degeneration  

Microsoft Academic Search

Paclitaxel causes a sensory polyneuropathy with characteristic features of distal axonal degeneration. Although the exact mechanisms underlying distal axonal degeneration are unknown, paclitaxel-induced axonal degeneration has been shown to be associated with an increase in detyrosinated tubulin. Here we show that recombinant human erythropoietin prevents axonal degeneration in sensory neurons in vitro and this effect is associated with downregulation of

Giorgia Melli; Christelene Jack; George L. Lambrinos; Mathias Ringkamp; Ahmet Höke

2006-01-01

188

Taxol-induced Rose Microtubule PolymerizationInVitroand itsinhibitionby Colchicine  

Microsoft Academic Search

Tubulin was isolatedfrom culturedcellsof rose (Rosa,sp.cv.Paul'sscarlet)by DEAE-Sephadex A50 chromatography, and thetaxol-inducedpolymerizationofmicrotubules in vitrowas characterizedat 24°C by turbiditydevelopment, sedimentation analysis,and electronmicroscopy.Numerous, shortmicrotubuleswere formed inthe presence of taxol, and maximum levelsof turbidityand polymer yieldwere obtained at -2:1 molar ratiosof taxolto tubulin.The criticalconcentrationof rose tubulinforpolymerizationin saturating taxolwas estimatedto be 0.21mg\\/ml .Colchicineinhibitedthe taxol-inducedpolymerization of tubulin as shown by sedimentation assays; however, much higher concentrationsof

LOUIS C. MOREJOHN; DONALD E. FOSKET

1984-01-01

189

Management of Paclitaxel-Induced Hand-Foot Syndrome  

PubMed Central

Summary Background Hand-foot syndrome (HFS), also known as acral erythema or palmoplantar dysesthesia, is a manifestation of painful erythema and dysesthesia mostly occurring in the palms and soles. Although many chemotherapeutic agents have been shown to cause HFS, it remains an uncommon adverse cutaneous manifestation of paclitaxel. Case Report We report a case of paclitaxel-induced grade 3 HFS in a patient with breast cancer. HFS developed after 6 weeks of paclitaxel weekly infusions. The patient was managed by avoidance of sun exposure and extensive use of sunscreen and moisturizers. The skin lesions stabilized and improved gradually. This allowed us to continue the planned necessary course of 12 weeks of paclitaxel under close surveillance. Conclusion Paclitaxel-induced HFS can be managed with topical creams and avoidance of sun exposure without the need to discontinue chemotherapy. However, close monitoring for any increase or change in symptoms is warranted.

Assi, Hussein A.; Ayoub, Zeina A.; Jaber, Sara M.; Sibai, Hassan A.; El Saghir, Nagi S.

2013-01-01

190

Differential effects of Paclitaxel on dendritic cell function  

PubMed Central

Background The potential utility of dendritic cells (DC) as cancer vaccines has been established in early trials in human cancers. The concomitant administration of cytotoxic agents and DC vaccines has been previously avoided due to potential immune suppression by chemotherapeutics. Recent studies show that common chemotherapy agents positively influence adaptive and innate anti-tumour immune responses. Results We investigated the effects of paclitaxel on human DC biology in vitro. DCs appear to sustain a significant level of resistance to paclitaxel and maintain normal viability at concentrations of up to 100 ?mol. In some cases this resistance against paclitaxel is significantly better than the level seen in tumour cell lines. Paclitaxel exposure led to a dose dependent increase in HLA class II expression equivalent to exposure to lipopolysaccharide (LPS), and a corresponding increase in proliferation of allogeneic T cells at the clinically relevant doses of paclitaxel. Increase in HLA-Class II expression induced by paclitaxel was not blocked by anti TLR-4 antibody. However, paclitaxel exposure reduced the endocytic capacity of DC but reduced the expression of key pro-inflammatory cytokines such as IL-12 and TNF?. Key morphological changes occurred when immature DC were cultured with 100 ?mol paclitaxel. They became small rounded cells with stable microtubules, whereas there were little effects on LPS-matured DC. Conclusions The effect of paclitaxel on human monocyte derived DC is complex, but in the clinical context of patients receiving preloaded and matured DC vaccines, its immunostimulatory potential and resistance to direct cytotoxicity by paclitaxel would indicate potential advantages to co-administration with vaccines.

2010-01-01

191

Electron Paramagnetic Resonance Highlights That the Oxygen Effect Contributes to the Radiosensitizing Effect of Paclitaxel  

PubMed Central

Background Paclitaxel (PTX) is a potent anti-cancer chemotherapeutic agent and is widely used in the treatments of solid tumors, particularly of the breast and ovaries. An effective and safe micellar formulation of PTX was used to administer higher doses of PTX than Taxol® (the current commercialized drug). We hypothesize that PTX-loaded micelles (M-PTX) may enhance tumor radiosensitivity by increasing the tumor oxygenation (pO2). Our goals were (i) to evaluate the contribution of the “oxygen effect” to the radiosensitizing effect of PTX; (ii) to demonstrate the therapeutic relevance of the combination of M-PTX and irradiation and (iii) to investigate the underlying mechanisms of the observed oxygen effect. Methodology and Principal Findings We used (PEG-p-(CL-co-TMC)) polymeric micelles to solubilize PTX. pO2 was measured on TLT tumor-bearing mice treated with M-PTX (80 mg/kg) using electron paramagnetic resonance (EPR) oximetry. The regrowth delay following 10 Gy irradiation 24 h after M-PTX treatment was measured. The tumor perfusion was assessed by the patent blue staining. The oxygen consumption rate and the apoptosis were evaluated by EPR oximetry and the TUNEL assay, respectively. EPR oximetry experiments showed that M-PTX dramatically increases the pO2 24 h post treatment. Regrowth delay assays demonstrated a synergy between M-PTX and irradiation. M-PTX increased the tumor blood flow while cells treated with M-PTX consumed less oxygen and presented more apoptosis. Conclusions M-PTX improved the tumor oxygenation which leads to synergy between this treatment and irradiation. This increased pO2 can be explained both by an increased blood flow and an inhibition of O2 consumption.

Magotteaux, Nicolas; De Preter, Geraldine; Ucakar, Bernard; Karroum, Oussama; Jordan, Benedicte; Gallez, Bernard; Preat, Veronique

2012-01-01

192

Paclitaxel metabolism in rat and human liver microsomes is inhibited by phenolic antioxidants  

Microsoft Academic Search

Paclitaxel is an important, recently introduced anti-neoplastic drug. Paclitaxel metabolites are virtually inactive in comparison with the parent drug. The study investigated whether phenolic antioxidants could inhibit metabolic inactivation sufficiently to increase paclitaxel effects. Cytochrome P450 (CYP)-catalysed metabolism of paclitaxel was investigated in rat and human liver microsomes. In rat microsomes, paclitaxel was metabolised mainly to C3'-hydroxypaclitaxel (C3'-OHP), less to

Radka Václavíková; Stanislav Horský; Petr Šimek; Ivan Gut

2003-01-01

193

Paclitaxel-loaded poly(glycolide-co-?-caprolactone)-b-D-?-tocopheryl polyethylene glycol 2000 succinate nanoparticles for lung cancer therapy  

PubMed Central

In order to improve the therapeutic efficacy and minimize the side effects of lung cancer chemotherapy, the formulation of paclitaxel-loaded poly(glycolide-co-?-caprolactone)-b-D-?-tocopheryl polyethylene glycol 2000 succinate nanoparticles (PTX-loaded [PGA-co-PCL]-b-TPGS2k NPs) was prepared. The novel amphiphilic copolymer (PGA-co-PCL)-b-TPGS2k was synthesized by ring-opening polymerization and characterized by proton nuclear magnetic resonance spectroscopy and gel permeation chromatography. The PTX-loaded (PGA-co-PCL)-b-TPGS2k NPs were characterized in terms of size, size distribution, zeta potential, drug encapsulation, surface morphology, and drug release. In vitro cellular uptakes of NPs were investigated with confocal laser scanning microscopy, indicating the coumarin 6-loaded (PGA-co-PCL)-b-TPGS2k NPs could be internalized by human lung cancer A-549 cells. The antitumor effect of PTX-loaded NPs was evaluated, both in vitro and in vivo, on an A-549 cell tumor-bearing mouse model via intratumoral injection. The commercial PTX formulation Taxol was chosen as the reference. Experimental results showed that the PTX-loaded NPs possessed higher cytotoxicity and could effectively inhibit the growth of tumor. All the results suggested that amphiphilic copolymer (PGA-co-PCL)-b-TPGS2k could act as a potential biological material for nanoformulation in the treatment of lung cancer.

Zhao, Tiejun; Chen, Hezhong; Dong, Yuchao; Zhang, Jiajun; Huang, Haidong; Zhu, Ji; Zhang, Wei

2013-01-01

194

Defining the Role of APC in the Mitotic Spindle Checkpoint In Vivo: APC Deficient Cells Are Resistant to Taxol  

PubMed Central

Mutations in the adenomatous polyposis coli (APC) tumour suppressor are the key initiating event of colorectal cancer. Although the control of WNT signaling is well established as a central tumour suppressive function, the significance of APC in regulating chromosome instability is less well established. In this study, we test whether APC-deficient cells have a functional spindle assembly checkpoint in vivo by examining the response of these cells to Taxol and Vinorelbine. Here we show for the first time that APC deficiency compromises the arrest response to Taxol in vivo. This effect is independent of the role APC plays in WNT signaling. At higher levels of Taxol, APC-deficient cells arrest as efficiently as wild-type cells. Importantly, this dose of Taxol strongly suppresses intestinal tumourigenesis in models of benign (APCMin/+ mouse) and invasive (AhCreER+ APCfl/+ PTENfl/fl) cancer. In contrast to intestinal enterocytes with a general spindle assembly checkpoint defect due to Bub1 deletion, APC-deficient enterocytes arrest equivalently to wild-type when treated with Vinorelbine. This suggests that the failed arrest in response to Taxol is due to a specific defect in microtubule stabilisation following Taxol treatment rather than a general role of the APC protein in the mitotic spindle checkpoint. In summary, this study clarifies the role of APC as a mitotic spindle checkpoint protein in vivo and shows that APC-deficient cells have a compromised response to Taxol.

Radulescu, Sorina; Ridgway, Rachel A; Appleton, Paul; Kroboth, Karin; Patel, Satish; Woodgett, James; Taylor, Stephen; Nathke, Inke S; Sansom, Owen J

2010-01-01

195

The effects of thalidomide and minocycline on taxol-induced hyperalgesia in rats  

PubMed Central

Chemotherapy-induced pain is the most common treatment-limiting complication encountered by cancer patients receiving taxane-, vinca alkaloid- or platin-based chemotherapy. Several lines of evidence indicate that activation of pro-inflammatory cascades involving the release of cytokines including tumor necrosis factor-alpha (TNF-?), interleukin-1 beta (IL-1?) and interleukin-6 (IL-6) as well as various growth factors are key events in the pathogenesis of many types of nerve-injury related pain. Similar mechanisms might also be involved in the etiology of chemotherapy-induced pain. Thalidomide and minocycline have profound immunomodulatory actions in addition to their originally intended pharmacological actions. These compounds were evaluated here for effects in preventing the development of taxol-induced mechanical and thermal hyperalgesia in rats. Thalidomide (50.0 mg/kg) reduced taxol-induced mechanical allodynia and hyperalgesia whereas minocycline (20.0 mg/kg) reduced taxol-induced mechanical hyperalgesia and allodynia as well as taxol-induced thermal hyperalgesia. These results suggest that immunomodulatory agents may provide a treatment option for the protection or reversal of chemotherapy-related pain.

Cata, Juan P.; Weng, Han-Rong

2008-01-01

196

Chemotherapy Drugs Thiocolchicoside and Taxol Permeabilize Lipid Bilayer Membranes by Forming Ion Pores  

Microsoft Academic Search

We report ion channel formation by chemotherapy drugs: thiocolchicoside (TCC) and taxol (TXL) which primarily target tubulin but not only. For example, TCC has been shown to interact with GABAA, nuclear envelope and strychnine-sensitive glycine receptors. TXL interferes with the normal breakdown of microtubules inducing mitotic block and apoptosis. It also interacts with mitochondria and found significant chemotherapeutic applications for

M Duszyk; J A Tuszynski

2011-01-01

197

Driving p53 Response to Bax Activation Greatly Enhances Sensitivity to Taxol by Inducing Massive Apoptosis  

PubMed Central

Abstract The proapoptotic gene bax is one of the downstream effectors of p53. The p53 binding site in the bax promoter is less responsive to p53 than the one in the growth arrest mediating gene p21. We introduced the bax gene under the control of 13 copies of a strong p53 responsive element into two ovarian cancer cell lines. The clones expressing bax under the control of p53 obtained from the wild-type (wt) p53-expressing cell line A2780 were much more sensitive (500- to 1000-fold) to the anticancer agent taxol than the parent cell line, with a higher percentage of cells undergoing apoptosis after drug treatment that was clearly p53-dependent and bax-mediated. Xenografts established in nude mice from one selected clone (A2780/C3) were more responsive to taxol than the parental line and the apoptotic response of A2780/C3 tumors was also increased after treatment. Introduction of the same plasmid into the p53 null SKOV3 cell line did not alter the sensitivity to taxol or the induction of apoptosis. In conclusion, driving the p53 response (after taxol treatment) by activating the bax gene rather than the p21 gene results in induction of massive apoptosis, in vitro and in vivo, and greatly enhances sensitivity to the drug.

De Feudis, Paola; Vignati, Sara; Rossi, Cosmo; Mincioni, Tatiana; Giavazzi, Raffaella; D'Incalci, Maurizio; Broggini, Massimo

2000-01-01

198

Development of paclitaxel-TyroSpheres for topical skin treatment  

PubMed Central

A potential topical psoriasis therapy has been developed consisting of tyrosine-derived nanospheres (TyroSpheres) with encapsulated anti-proliferative paclitaxel. TyroSpheres provide enhancement of paclitaxel solubility (almost 4,000 times greater than PBS) by effective encapsulation and enable sustained, dose-controlled release over 72 hours under conditions mimicking skin permeation. TyroSpheres offer potential in the treatment of psoriasis, a disease resulting from over-proliferation of keratinocytes in the basal layer of the epidermis, by (a) enabling delivery of paclitaxel into the epidermis at concentrations >100 ng/cm2 of skin surface area and (b) enhancing the cytotoxicity of loaded paclitaxel to human keratinocytes (IC50 of paclitaxel-TyroSpheres was approximately 45% lower than that of free paclitaxel). TyroSpheres were incorporated into a gel-like viscous formulation to improve their flow characteristics with no impact on homogeneity, release or skin distribution of the payload. The findings reported here confirm that the TyroSpheres provide a platform for paclitaxel topical administration allowing skin drug localization and minimal systemic escape.

Kilfoyle, Brian E.; Sheihet, Larisa; Zhang, Zheng; Laohoo, Marissa; Kohn, Joachim; Michniak-Kohn, Bozena B.

2012-01-01

199

The interaction of taxol and vinblastine with radiation induction of p53 and p21 WAF1/CIP1.  

PubMed Central

The combination of the microtubule active drug taxol with radiation has shown promise for use in combined modality therapy. Recent studies have demonstrated that radiation and a wide range of chemotherapy agents, including microtubule active drugs, induce p53. In certain circumstances, the induction of p53 has been shown to be an important parameter in the response of a tumour to cytotoxic treatment. We examined the induction of p53 and its downstream target, p21WAF1/CIP1, by the microtubule active agents taxol and vinblastine with radiation. An increase in induction of both p53 and p21 WAF1/CIP1 was demonstrated when radiation was added to either taxol or vinblastine treatment. These results, in conjunction with data on taxol and vinblastine induction of p21WAF1/CIP1, suggest a rationale for the combination therapy. Images Figure 2 Figure 1

Tishler, R. B.; Lamppu, D. M.

1996-01-01

200

Sequence-dependent cytotoxic effects due to combinations of cisplatin and the antimicrotubule agents taxol and vincristine  

Microsoft Academic Search

The antineoplastic activity that taxol has demonstrated in advanced ovarian cancer and other neoplasms in which the platinum analogues are among the most active agents has been the impetus for the development of taxol\\/platinum combination regimens. Since both classes of agents are known to induce cell-cycle-dependent effects and to delay cell-cycle traverse in specific phases of the cycle, an evaluation

Eric K. Rowinsky; Martin J. Citardi; Dennis A. Noe; Ross C. Donehower

1993-01-01

201

Clinical trials and progress with paclitaxel in ovarian cancer  

PubMed Central

Paclitaxel is a front-line agent for ovarian cancer chemotherapy, along with the platinum agents. Derived from the Pacific yew tree, Taxus brevifolia, paclitaxel has covered significant ground from the initial discovery of its antineoplastic properties to clinical applications in many forms of human cancers, including ovarian cancer. Although much has been published about the unique mechanism of action of this agent, several issues remain to be resolved. Finding the appropriate dosage schedule for paclitaxel in chemo-naïve and recurrent ovarian cancer, defining the role of paclitaxel in maintenance chemotherapy, and elucidating the mechanisms of taxane resistance are areas of intense research. Newer forms of taxanes are being manufactured to avoid troublesome adverse effects and to improve clinical efficacy. These issues are reviewed in detail in this paper with an emphasis on clinically relevant evidence-based information.

Kumar, Sanjeev; Mahdi, Haider; Bryant, Christopher; Shah, Jay P; Garg, Gunjal; Munkarah, Adnan

2010-01-01

202

Inhibitory Effect of Paclitaxel on Endothelial Cell Adhesion and Migration  

Microsoft Academic Search

The long-term success of percutaneous coronary interventions has been limited by restenosis. Therefore, local delivery of paclitaxel, an antiproliferative agent, using drug-eluting stents has been applied to prevent in-stent restenosis. However, paclitaxel not only inhibits smooth muscle cell proliferation, but also delays re-endothelialization of the damaged site, which may cause potentially life-threatening cardiovascular adverse events, especially late and very late

Hua Li; Li-jun Zhang; Bai-hua Chen; Xuan Zhou; Ke Su; Wen-tao Shi; Jun-zhu Wu; Hong Yu; Lei Wei

2010-01-01

203

Preclinical evaluation of alternative pharmaceutical delivery vehicles for paclitaxel.  

PubMed

New solubilizers, including Sorporol 230, Sorporol 120Ex, Aceporol 345-T, Aceporol 460 and Riciporol 335, as potential new delivery vehicles for paclitaxel were investigated, since recent studies have shown that the paclitaxel delivery vehicle Cremophor EL significantly alters the pharmacokinetics of paclitaxel. Cremophor EL and Tween 80 were used as a reference. As in the case of Cremophor EL, alteration of blood distribution of paclitaxel occurred in the presence of all tested vehicles. Also, no differences in the affinity of paclitaxel for the tested solubilizers was found during equilibrium dialysis experiments. The different vehicles could be distinguished by a different rate of esterase-mediated breakdown, which was correlated with the fatty acid content of the solubilizers. The activation of the complement cascade was less pronounced for all solubilizers, except Riciporol 335, compared to Cremophor EL. The strategies presented here provide the possibility to rapidly screen future candidate delivery vehicles with optimal characteristics for use as a solubilizer in clinical formulations of paclitaxel or other poorly water-soluble drugs. PMID:12187334

Loos, Walter J; Szebeni, Janos; ten Tije, Albert J; Verweij, Jaap; van Zomeren, Desirée M; Chung, Kyu-nung; Nooter, Kees; Stoter, Gerrit; Sparreboom, Alex

2002-08-01

204

Inhibition study on insulin fibrillation and cytotoxicity by paclitaxel.  

PubMed

Alzheimer, a neurodegenerative disease, and a large variety of pathologic conditions are associated with a form of protein aggregation known as amyloid fibrils. Since fibrils and prefibrillar intermediates are cytotoxic, numerous attempts have been made to inhibit fibrillation process as a therapeutic strategy. Peptides, surfactants and aromatic small molecules have been used as fibrillation inhibitors. Here we studied the effects of paclitaxel, a polyphenol with a high tendency for interaction with proteins, on fibrillation of insulin as a model protein. The effects of paclitaxel on insulin fibrillation were determined by Thioflavin T fluorescence, Congo red absorbance, circular dichroism and atomic force microscopy. These studies indicated that paclitaxel considerably hindered nucleation, and therefore, fibrillation of insulin in a dose-dependant manner. The isothermal titration calorimetry studies showed that the interaction between paclitaxel and insulin was spontaneous. In addition, the van der Waal's interactions and hydrogen bonds were prominent forces contributing to this interaction. Computational results using molecular dynamic simulations and docking studies revealed that paclitaxel diminished the polarity of insulin dimer and electrostatic interactions by increasing the hydrophobicity of its dimer state. Furthermore, paclitaxel reduced disrupting effects of insulin fibrils on PC12 cell's neurite outgrowth and complexity, and enhanced their survival. PMID:24535601

Kachooei, Ehsan; Moosavi-Movahedi, Ali Akbar; Khodagholi, Fariba; Mozaffarian, Faroogh; Sadeghi, Payam; Hadi-Alijanvand, Hamid; Ghasemi, Atiyeh; Saboury, Ali Akbar; Farhadi, Mohammad; Sheibani, Nader

2014-06-01

205

Enhancement of the Therapeutic Efficacy of Taxol by the Mitogen-Activated Protein Kinase Kinase Inhibitor CI1040 in Nude Mice Bearing Human Heterotransplants  

Microsoft Academic Search

Taxol may contribute to intrinsic chemoresistance by activat- ing the mitogen-activated protein kinase kinase (MEK)\\/ extracellular signal-regulated kinase (ERK) cytoprotective pathway in human cancer cell lines and tumors. We have previously shown additivity between Taxol and the MEK inhibitor, U0126 in human cancer cell lines. Here, the combination of Taxol with an orally bioavailable MEK inhibitor, CI-1040, was evaluated in

Hayley M. McDaid; Lluis Lopez-Barcons; Aaron Grossman; Marie Lia; Steven Keller; Susan Band Horwitz

2005-01-01

206

Effect of Ethyl Pyruvate on Paclitaxel-Induced Neuropathic Pain in Rats  

PubMed Central

Background Although paclitaxel is a widely used chemotherapeutic agent for the treatment of solid cancers, side effects such as neuropathic pain lead to poor compliance and discontinuation of the therapy. Ethyl pyruvate (EP) is known to have analgesic effects in several pain models and may inhibit apoptosis. The present study was designed to investigate the analgesic effects of EP on mechanical allodynia and apoptosis in dorsal root ganglion (DRG) cells after paclitaxel administration. Methods Rats were randomly divided into 3 groups: 1) a control group, which received only vehicle; 2) a paclitaxel group, which received paclitaxel; and 3) an EP group, which received EP after paclitaxel administration. Mechanical allodynia was tested before and at 7 and 14 days after final paclitaxel administration. Fourteen days after paclitaxel treatment, DRG apoptosis was determined by activated caspase-3 immunoreactivity (IR). Results Post-treatment with EP did not significantly affect paclitaxel-induced allodynia, although it tended to slightly reduce sensitivities to mechanical stimuli after paclitaxel administration. After paclitaxel administration, an increase in caspase-3 IR in DRG cells was observed, which was co-localized with NF200-positive myelinated neurons. Post-treatment with EP decreased the paclitaxel-induced caspase-3 IR. Paclitaxel administration or post-treatment with EP did not alter the glial fibrillary acidic protein IRs in DRG cells. Conclusions Inhibition of apoptosis in DRG neurons by EP may not be critical in paclitaxel-induced mechanical allodynia.

Choi, Seong Soo; Koh, Won Uk; Nam, Jae Sik; Shin, Jin Woo; Leem, Jeong Gill

2013-01-01

207

Inhibitory effect of taxol, a microtubule stabilizing agent, on induction of DNA synthesis is dependent upon cell lines and growth factors.  

PubMed

Growth-arrested rat fibroblasts, 3Y1, and human diploid fibroblasts, TIG-1, were induced to synthesize DNA by stimulation with various agents such as fetal bovine serum (FBS), epidermal growth factor (EGF), colcemid, or colchicine. Taxol, a microtubule-stabilizing agent, blocked the induction of DNA synthesis after stimulation with colcemid or colchicine in both cell lines. Taxol inhibited the induction of DNA synthesis after stimulation with FBS or EGF in TIG-1, but did not in 3Y1. 12-O-tetradecanoylphorbol-13-acetate (TPA) induced DNA synthesis in TIG-1, which was reduced only partly by taxol. Taxol stabilized or polymerized microtubules in both cell lines. These results indicate that the inhibitory effect of taxol on the induction of DNA synthesis varied among cell lines and among growth factors, and suggest that signal transduction processes may be differentiated by taxol sensitivity. In TIG-1 cells, when taxol was added within 6 h, about halfway into the initiation of DNA synthesis after the addition of FBS or EGF, the inhibition of DNA synthesis still occurred. Taxol did not inhibit the induction of c-fos and c-myc genes by FBS or EGF stimulation. Colchicine itself did not induce these genes in TIG-1. Thus, taxol appeared to inhibit the induction of DNA synthesis not by blockage in the early transduction process of the growth signal from the cell surface to nuclei but by blockage in processes operating in the mid- or late-prereplicative phase. PMID:1351422

Tsuji, K; Ueno, A; Ide, T

1992-04-01

208

Effect of Smac and Taxol on non-small-cell lung cancer.  

PubMed

A series of structurally unique second mitochondria-derived activator of caspases (Smacs) that act as antagonists of the inhibitor of apoptosis proteins (IAPs) directly have been discovered. They play crucial roles in mitochondrial apoptosis pathways and promote chemotherapy-induced apoptosis. In this study, we constructed a eukaryotic expression vector pcDNA3.1/Smac and transfected it into A549 human lung cancer cells. Then we analyzed the cell invasive and cloning ability, as well as cell apoptosis induced by Taxol. The results showed that over-expressed Smac significantly inhibited A549 cell invasive and cloning ability and promoted apoptosis following Taxol treatment. This finding provides a potential approach for the biological therapy of lung cancer. PMID:24681884

Peng, Chuanliang; Hao, Yingtao; Zhao, Yunpeng; Sun, Qifeng; Zhao, Xiaogang; Cong, Bo

2014-05-01

209

Anti-invasion and anti-angiogenesis effect of taxol and camptothecin on melanoma cells  

Microsoft Academic Search

Two highly invasive melanoma cell lines B16BL6 and B16F10 were used to investigate the anti-invasion and anti-angiogenesis action of taxol and camptothecin (CPT). The adhesion of melanoma cells was tested by optical absorbance at 545?nm. The invasive activity of these cells was tested in a transwell cell chamber assay. The cell migration within a 3D collagen matrix was recorded with

Fang Wang; Yu Cao; Hong-Yan Liu; Shao-Feng Xu; Rui Han

2003-01-01

210

Cordyceps sinensis Health Supplement Enhances Recovery from Taxol-Induced Leukopenia  

Microsoft Academic Search

This study aimed to evaluate the ability of the health food supplement Cordyceps sinensis (CS) to ameliorate suppressive effects of chemotherapy on bone marrow function as a model for cancer treatment. Mice were treated with Taxol (17 mg\\/kg body wt) one day before oral administration of a hot-water extract of CS (50 mg\\/kg daily) that was given daily for 3

WEI-CHUNG LIU; WEI-LING CHUANG; MIN-LUNG TSAI; JI-HONG HONG; WILLIAM H. MCBRIDE; CHI-SHIUN CHIANG

211

Preliminary assessment of the C13-side chain 2'-hydroxylase involved in Taxol biosynthesis  

SciTech Connect

The biosynthesis of the anticancer drug Taxol in yew (Taxus) species is thought to involve the preliminary formation of the advanced taxane diterpenoid intermediate baccatin III upon which the functionally important N-benzoyl phenylisoserinoyl side chain is subsequently assembled at the C13-O-position. In vivo feeding studies with Taxus tissues and characterization of the two transferases responsible for C13-side chain construction have suggested a sequential process in which an aminomutase converts {alpha}-phenylalanine to {beta}-phenylalanine which is then activated to the corresponding CoA ester and transferred to baccatin III to yield {beta}-phenylalanoyl baccatin III (i.e., N-debenzoyl-2'-deoxytaxol) that undergoes subsequent 2'-hydroxylation and N-benzoylation to afford Taxol. However, because the side chain transferase can utilize both {beta}-phenylalanoyl CoA and phenylisoserinoyl CoA in the C13-O-esterification of baccatin III, ambiguity remained as to whether the 2'-hydroxylation step occurs before or after transfer of the amino phenylpropanoyl moiety. Using cell-free enzyme systems from Taxus suspension cells, no evidence was found for the direct hydroxylation of {beta}-phenylalanine to phenylisoserine; however, microsomal preparations from this tissue appeared capable of the cytochrome P450-mediated hydroxylation of {beta}-phenylalanoyl baccatin III to phenylisoserinoyl baccatin III (i.e., N-debenzoyltaxol) as the penultimate step in the formation of Taxol and related N-substituted taxoids. These preliminary results, which are consistent with the proposed side chain assembly process, have clarified an important step of Taxol biosynthesis and set the foundation for cloning the responsible cytochrome P450 hydroxylase gene.

Long, Robert M. [Institute of Biological Chemistry, Washington State University, Pullman, WA 99164-6340 (United States); Croteau, Rodney [Institute of Biological Chemistry, Washington State University, Pullman, WA 99164-6340 (United States)]. E-mail: croteau@wsu.edu

2005-12-09

212

Survivin is required for stable checkpoint activation in taxol-treated HeLa cells  

Microsoft Academic Search

gradual increase in the percentage of multinucleated cells in the culture. Time-lapse imaging of synchronized cultures revealed that control and Survivin-depleted cells arrested in mitosis in the presence of nocodazole; however, the latter failed to arrest in mitosis when treated with taxol. Immunofluorescence studies revealed that Survivin- depleted cells were unable to stably maintain BubR1 at the kinetochores in the

Ana Carvalho; Mar Carmena; Clara Sambade; William C. Earnshaw; Sally P. Wheatley

2003-01-01

213

Effect of taxol on the heparin-induced secretion of lipoprotein lipase from cardiac myocytes  

Microsoft Academic Search

The heparin-induced secretion of LPL into the incubation medium of cardiac myocytes occurred in two phases: a rapid release (5–10 min), followed by a slower rate of release (10–60 min). Reducing the incubation temperature from 37° C to 23° C inhibited the slow phase of secretion, but had no effect on the rapid phase. Similarly, taxol, a microtubule-stabilizing drug, selectively

David L. Severson; Rogayah Carroll

1989-01-01

214

Comparative effects of taxol and Taxotere on two different human carcinoma cell lines  

Microsoft Academic Search

The effects of taxoids (taxol and Taxotere) were followed on two human cancerous cell lines (bladder carcinoma J82 cells and epidermoid carcinoma KB 3-1 cells). Three cellular parameters were studied, viz., the qualitative effect on cellular microtubules, the quantitation of tubulin, and the antimitotic action, using two-parametric flow-cytometric analyses in treated cells. In both of the cell lines the tubulin

Patrick Garcia; Diane Braguer; Gérard Carles; Said El Khyari; Yves Barra; Concepcion Ines; Isabel Barasoain; Claudette Briand

1994-01-01

215

Radial Compression of Microtubules and the Mechanism of Action of Taxol and Associated Proteins  

Microsoft Academic Search

Microtubules (MTs) are hollow cylindrical polymers composed of ??-tubulin heterodimers that align head-to-tail in the MT wall, forming linear protofilaments that interact laterally. We introduce a probe of the interprotofilament interactions within MTs and show that this technique gives insight into the mechanisms by which MT-associated proteins (MAPs) and taxol stabilize MTs. In addition, we present further measurements of the

Daniel J. Needleman; Miguel A. Ojeda-Lopez; Uri Raviv; Kai Ewert; Herbert P. Miller; Leslie Wilson; Cyrus R. Safinya

2005-01-01

216

Anti-invasion and anti-angiogenesis effect of taxol and camptothecin on melanoma cells.  

PubMed

Two highly invasive melanoma cell lines B16BL6 and B16F10 were used to investigate the anti-invasion and antiangiogenesis action of taxol and camptothecin (CPT). The adhesion of melanoma cells was tested by optical absorbance at 545 nm. The invasive activity of these cells was tested in a transwell chamber assay. The cell migration within a 3D collagen matrix was recorded with a time-lapse video recorder and analyzed by computer-assisted cell tracking. Gelatin zymography was used to study the metalloproteinase activity. The chicken chorioallantoic membrane (CAM) model was used to study the anti-angiogenesis effect of the two drugs. The results demonstrated that both taxol and CPT could inhibit the migration of B16F10 cells, and inhibit the adhesion of B16F10 to fibronectin and laminin. They can reduce the metalloproteinase secretion of HT1080 and exhibit the antiangiogenesis effect in the CAM model. Taxol showed a highly anti-invasion effect on B16BL6 cells while CPT did not exhibit such an effect. PMID:12765196

Wang, Fang; Cao, Yu; Liu, Hong-Yan; Xu, Shao-Feng; Han, Rui

2003-06-01

217

Cordyceps sinensis Health Supplement Enhances Recovery from Taxol-Induced Leukopenia  

PubMed Central

This study aimed to evaluate the ability of the health food supplement Cordyceps sinensis (CS) to ameliorate suppressive effects of chemotherapy on bone marrow function as a model for cancer treatment Mice were treated with Taxol (17 mg/kg body wt) one day before oral administration of a hot-water extract of CS (50 mg/kg daily) that was given daily for 3 weeks. White blood cell counts in peripheral blood of mice receiving Taxol were at 50% of normal levels on day 28 but had recovered completely in mice treated with CS. In vitro assays showed that CS enhanced the colony-forming ability of both granulocyte macrophage colony forming unit (GM-CFU) and osteogenic cells from bone marrow preparations and promoted the differentiation of bone marrow mesenchymal stromal cells into adipocytes, alkaline phosphatase–positive osteoblasts, and bone tissue. This result could be attributed to enhanced expression of Cbfa1 (core binding factor a) and BMP-2 (bone morphogenetic protein) with concurrent suppression of ODF (osteoclast differentiation factor/RANK [receptor activator of NF-?B]) ligand. In summary, CS enhances recovery of mice from leukopenia caused by Taxol treatment. It appears to do so by protecting both hematopoietic progenitor cells directly and the bone marrow stem cell niche through its effects on osteoblast differentiation.

Liu, Wei-Chung; Chuang, Wei-Ling; Tsai, Min-Lung; Hong, Ji-Hong; McBride, William H.; Chiang, Chi-Shiun

2009-01-01

218

Preparation of nano-emulsified paclitaxel using MPEG–PLGA diblock copolymers  

Microsoft Academic Search

In this work, we prepared nano-emulsified paclitaxel using administration form of the self-microemulsifying drug delivery systems (SMEDDS) in order to increase efficacy of paclitaxel. As paclitaxel delivery carrier, we chose MPEG–PLGA diblock copolymers with different hydrophilic and hydrophobic balances (HLB) by changing PLGA segments under constant MPEG segment. Paclitaxel and MPEG–PLGA diblock copolymers were dissolved by solubilizer such as tetraglycol,

Soo Young Lee; Hoon Hyun; Ju Yong Youn; Byung Soo Kim; In Beum Song; Moon Suk Kim; Bong Lee; Gilson Khang; Hai Bang Lee

2008-01-01

219

Taxol biosynthesis: Identification and characterization of two acetyl CoA:taxoid-O-acetyl transferases that divert pathway flux away from Taxol production¶  

PubMed Central

Two cDNAs encoding taxoid-O-acetyl transferases (TAX 9 and TAX 14) were obtained from a previously isolated family of Taxus acyl/aroyl transferase cDNA clones. The recombinant enzymes catalyze the acetylation of taxadien-5?,13?-diacetoxy-9?,10?-diol to generate taxadien-5?,10?,13?-tri-acetoxy-9?-ol and taxadien-5?,9?,13?-triacetoxy-10?-ol, respectively, both of which then serve as substrates for a final acetylation step to yield taxusin, a prominent side route metabolite of Taxus. Neither enzyme acetylate the 5?- or the 13?-hydroxyls of taxoid polyols, indicating that prior acylations is required for efficient peracetylation to taxusin. Both enzymes were kinetically characterized, and the regioselectivity of acetylation was shown to vary with pH. Sequence comparison with other taxoid acyl transferases confirmed that primary structure of this enzyme type reveals little about function in taxoid metabolism. Unlike previously identified acetyl transferases involved in Taxol production, these two enzymes appear to act exclusively on partially acetylated taxoid polyols to divert the Taxol pathway to side-route metabolites.

Hampel, Daniela; Mau, Christopher J.D.; Croteau, Rodney B.

2009-01-01

220

Interactions between Co-Habitating fungi Elicit Synthesis of Taxol from an Endophytic Fungus in Host Taxus Plants  

PubMed Central

Within a plant, there can exist an ecosystem of pathogens and endophytes, the latter described as bacterial and fungal inhabitants that thrive without causing disease to the host. Interactions between microbial inhabitants represent a novel area of study for natural products research. Here we analyzed the interactions between the fungal endophytes of Taxus (yew) trees. Fungal endophytes of Taxus have been proposed to produce the terpenoid secondary metabolite, Taxol, an anti-cancer drug. It is widely reported that plant extracts stimulate endophytic fungal Taxol production, but the underlying mechanism is not understood. Here, Taxus bark extracts stimulated fungal Taxol production 30-fold compared to a 10-fold induction with wood extracts. However, candidate plant-derived defense compounds (i.e., salicylic acid, benzoic acid) were found to act only as modest elicitors of fungal Taxol production from the endophytic fungus Paraconiothyrium SSM001, consistent with previous studies. We hypothesized the Taxus plant extracts may contain elicitors derived from other microbes inhabiting these tissues. We investigated the effects of co-culturing SSM001 with other fungi observed to inhabit Taxus bark, but not wood. Surprisingly, co-culture of SSM001 with a bark fungus (Alternaria) caused a ?threefold increase in Taxol production. When SSM001 was pyramided with both the Alternaria endophyte along with another fungus (Phomopsis) observed to inhabit Taxus, there was an ?eightfold increase in fungal Taxol production from SSM001. These results suggest that resident fungi within a host plant interact with one another to stimulate Taxol biosynthesis, either directly or through their metabolites. More generally, our results suggest that endophyte secondary metabolism should be studied in the context of its native ecosystem.

Soliman, Sameh S. M.; Raizada, Manish N.

2012-01-01

221

Paclitaxel chemotherapy: from empiricism to a mechanism-based formulation strategy  

PubMed Central

Paclitaxel is an anticancer agent effective for the treatment of breast, ovarian, lung, and head and neck cancer. Because of water insolubility, paclitaxel is formulated with the micelle-forming vehicle Cremophor EL to enhance drug solubility. However, the addition of Cremophor EL results in hypersensitivity reactions, neurotoxicity, and altered pharmacokinetics of paclitaxel. To circumvent these unfavorable effects resulting from the addition of Cremophor EL, efforts have been made to develop new delivery systems for paclitaxel administration. For example, ABI-007 is a Cremophor-free, albumin-stabilized, nanoparticle paclitaxel formulation that was found to have significantly less toxicity than Cremophor-containing paclitaxel in mice. Pharmacokinetic studies indicate that in contrast to Cremophor-containing paclitaxel, ABI-007 displays linear pharmacokinetics over the clinically relevant dose range of 135–300 mg/m2. In a phase III study conducted in patients with metastatic breast cancer, patients treated with ABI-007 achieved a significantly higher objective response rate and time to progression than those treated with Cremophor-containing paclitaxel. Together these findings suggest that nanoparticle albumin-bound paclitaxel may enable clinicians to administer paclitaxel at higher doses with less toxicity than is seen with Cremophor-containing paclitaxel. The role of this novel paclitaxel formulation in combination therapy with other antineoplastic agents needs to be determined.

Scripture, Charity D; Figg, William D; Sparreboom, Alex

2005-01-01

222

4-Deacetylbaccatin III: a proposed biosynthetic precursor of paclitaxel from the bark of Taxus wallichiana.  

PubMed

4-Deacetylbaccatin III was isolated and characterized from the bark of Taxus wallichiana Zucc. It was previously identified as an intermediate during the synthesis of paclitaxel and was proposed as a precursor for the biosynthesis of paclitaxel. Existence of 4-deacetylbaccatin III in T. wallichiana is strong evidence for the previously proposed biosynthetic pathway of paclitaxel via 4-deacetylbaccatin III. PMID:21213967

Nisar, Muhammad; Qayum, Mughal; Adhikari, Achyut; Khan, Inamullah; Kaleem, Waqar Ahamad; Ali, Zulfiqar; Choudhary, M Iqbal

2010-11-01

223

Formulation and pharmacokinetic evaluation of a paclitaxel nanosuspension for intravenous delivery  

PubMed Central

Paclitaxel is a diterpenoid isolated from Taxus brevifolia. It is effective for various cancers, especially ovarian and breast cancer. Due to its aqueous insolubility, it is administered dissolved in ethanol and Cremophor® EL (BASF, Ludwigshafen, Germany), which can cause serious allergic reactions. In order to eliminate Cremophor EL, paclitaxel was formulated as a nanosuspension by high-pressure homogenization. The nanosuspension was lyophilized to obtain the dry paclitaxel nanoparticles (average size, 214.4 ± 15.03 nm), which enhanced both the physical and chemical stability of paclitaxel nanoparticles. Paclitaxel dissolution was also enhanced by the nanosuspension. Differential scanning calorimetry showed that the crystallinity of paclitaxel was preserved during the high-pressure homogenization process. The pharmacokinetics and tissue distribution of paclitaxel were compared after intravenous administration of paclitaxel nanosuspension and paclitaxel injection. In rat plasma, paclitaxel nanosuspension exhibited a significantly (P < 0.01) reduced area under the concentration curve (AUC)0–? (20.343 ± 9.119 ?g · h · mL?1 vs 5.196 ± 1.426 ?g · h · mL?1), greater clearance (2.050 ± 0.616 L · kg?1 · h?1 vs 0.556 ± 0.190 L · kg?1 · h?1), and shorter elimination half-life (5.646 ± 2.941 vs 3.774 ± 1.352 hours) compared with the paclitaxel solution. In contrast, the paclitaxel nanosuspension resulted in a significantly greater AUC0–? in liver, lung, and spleen (all P < 0.01), but not in heart or kidney.

Wang, Yonglu; Li, Xueming; Wang, Liyao; Xu, Yuanlong; Cheng, Xiaodan; Wei, Ping

2011-01-01

224

Specificity of the N-benzoyl transferase responsible for the last step of Taxol biosynthesis?  

PubMed Central

The last few steps in the biosynthesis of the anticancer drug Taxol in yew (Taxus) species are thought to involve the attachment of ?-phenylalanine to the C13-O-position of the advanced taxane diterpenoid intermediate baccatin III to yield N-debenzoyl-2?-deoxytaxol, followed by hydroxylation on the side chain at the C2?-position to afford N-debenzoyltaxol, and finally N-benzoylation to complete the pathway. A cDNA encoding the N-benzoyl transferase that catalyzes the terminal step of the reaction sequence was previously isolated from a family of transferase clones (derived from an induced Taxus cell cDNA library) by functional characterization of the corresponding recombinant enzyme using the available surrogate substrate N-debenzoyl-2?-deoxytaxol [Walker et al., Proc. Natl. Acad. Sci. USA 99(2002) 9166–9171]. Semi-synthetic N-debenzoyltaxol was prepared by coupling of 7-triethylsilybaccatin III and (2R,3S)-?-phenylisoserine protected as the N-Boc N,O-isopropylidene derivative by means of carbodiimide activation and formic acid deprotections. The selectivity of the recombinant N-transferase for N-debenzoyltaxol was evaluated, and the enzyme was shown to prefer, by a catalytic efficiency factor of two, N-debenzoyltaxol over N-debenzoyl-2?-deoxytaxol as the taxoid co-substrate in the benzoyl transfer reaction, consistent with the assembly sequence involving 2?-hydroxylation prior to N-benzoylation. Selectivity for the acyl/aroyl-CoA co-substrate was also examined, and the enzyme was shown to prefer benzoyl CoA. Transfer from tigloyl-CoA to N-debenzoyltaxol to afford cephalomannine (taxol B) was not observed, nor was transfer observed from hexanoyl-CoA or butanoyl-CoA to yield taxol C or taxol D, respectively. These results support the proposed sequence of reactions for C13-O-side chain assembly in Taxol biosynthesis, and suggest that other N-transferases are responsible for the formation of related, late pathway, N-acylated taxoids.

Long, Robert M.; Lagisetti, Chandraiah; Coates, Robert M.; Croteau, Rodney B.

2008-01-01

225

Hydrophobically modified glycol chitosan nanoparticles as carriers for paclitaxel.  

PubMed

Self-assembled nanoparticles based on hydrophobically modified glycol chitosan (HGC) were prepared as a carrier for paclitaxel. HGC conjugates were prepared by chemically linking 5beta-cholanic acid to glycol chitosan chains using 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide chemistry. In phosphate-buffered saline (PBS; pH 7.4), the synthesized HGC conjugates formed nano-sized particles with a diameter of 200 nm and exhibited high thermodynamic stability as reflected by their low critical aggregation concentration (0.03 mg/ml). Paclitaxel was efficiently loaded into HGC nanoparticles up to 10 wt.% using a dialysis method. The paclitaxel-loaded HGC (PTX-HGC) nanoparticles were 400 nm in diameter and were stable in PBS for 10 days. These PTX-HGC nanoparticles also showed sustained release of the incorporated of paclitaxel (80% of the loaded dose was released in 8 days at 37 degrees C in PBS). Owing to sustained release, the PTX-HGC nanoparticles were less cytotoxic to B16F10 melanoma cells than free paclitaxel formulated in Cremophor EL. Injection of PTX-HGC nanoparticles into the tail vein of tumor-bearing mice prevented increases in tumor volume for 8 days. Finally, PTX was less toxic to the tumor-bearing mice when formulated in HGC nanoparticles than when formulated with Cremophor EL. PMID:16458988

Kim, Jong-Ho; Kim, Yoo-Shin; Kim, Sungwon; Park, Jae Hyung; Kim, Kwangmeyung; Choi, Kuiwon; Chung, Hesson; Jeong, Seo Young; Park, Rang-Woon; Kim, In-San; Kwon, Ick Chan

2006-03-10

226

Sensitization of taxol-induced apoptosis by curcumin involves down-regulation of nuclear factor-kappaB and the serine\\/threonine kinase Akt and is independent of tubulin polymerization  

Microsoft Academic Search

Taxol is the best anticancer agent that has ever been isolated from plants, but its major disadvantage is its dose-limiting toxicity. In this study, we report with mechanism-based evidence that curcumin, a nontoxic food additive commonly used by the Indian population, sensitizes tumor cells more efficiently to the therapeutic effect of Taxol. A combination of 5 nm Taxol with 5

Smitha V Bava; Vineshkumar T Puliappadamba; Ayswaria Deepti; Asha Nair; Devarajan Karunagaran; Ruby John Anto

2005-01-01

227

Effect of Taxol on cytochrome P450 3A and acetaminophen toxicity in cultured rat hepatocytes: comparison to dexamethasone.  

PubMed

The purpose of this study was to determine if Taxol induced CYP3A in primary cultures of rat hepatocytes and, if so, whether induction of CYP3A would increase acetaminophen toxicity. Taxol caused a concentration-dependent increase in the amount of immunoreactive CYP3A and in the steady-state levels of CYP3A1/DEX but not CYP3A2 mRNA. Similar concentration-dependent increases in toxicity as measured by a decrease in protein synthesis were observed after exposure of cells to acetaminophen for 7 hr whether cells were pretreated with Taxol or dexamethasone. Increased release of lactate dehydrogenase occured after 24 hr exposure to acetaminophen, with no further decreases in protein synthesis than those observed at 7 hr. Increases in acetaminophen toxicity correlated with increased covalent binding of acetaminophen to cellular proteins. Triacetyloleandomycin, a selective inhibitor of CYP3A, completely protected the cells against acetaminophen toxicity in both Taxol- and dexamethasone-pretreated cells and prevented the increase in covalent binding of acetaminophen to cellular proteins. These results demonstrate that Taxol, like dexamethasone, induces CYP3A and that increases in this P450 are responsible for increased acetaminophen toxicity. PMID:9007036

Kostrubsky, V E; Lewis, L D; Wood, S G; Sinclair, P R; Wrighton, S A; Sinclair, J F

1997-01-01

228

Ultrasound-potentiated salicylic acid-induced physiological effects and production of taxol in hazelnut (Corylus avellana L.) cell culture.  

PubMed

Effects of ultrasound (US), salicylic acid (SA) and their combined use on the growth and secondary metabolite production of suspension-cultured Corylus avellana cells were investigated. The cultures were treated with US (40 kHz) for short periods of time (2, 3, 5 and 10 min) and SA (25 and 50 mg L(-1)). Results showed that although phenolic content of the cells was significantly increased under exposure to treatments, flavonoids content significantly decreased. Taxol biosynthesis was improved by all treatments. US exposure increased the extracellular, cell-associated and total taxol yield three-, 1.6-, and two-fold compared with that of the control, respectively. SA at all levels was more effective than US in stimulating cell-associated and total taxol production. Combined treatment of US and SA at 50 mg L(-1) resulted in the most improvement in total taxol production, which was about seven times higher than that of the US, three times higher than that of the SA and 14 times higher than that of the control. The results suggest a synergism between US and SA in enhancing taxol production by hazelnut cells. PMID:21835541

Rezaei, Ayatollah; Ghanati, Faezeh; Behmanesh, Mehrdad; Mokhtari-Dizaji, Manijhe

2011-11-01

229

Taxane-specific monoclonal antibodies: measurement of taxol, baccatin III, and "total taxanes" in Taxus brevifolia extracts by enzyme immunoassay.  

PubMed

Three monoclonal antibodies with either specificity to taxol or baccatin III, or cross-reactivity with several common taxanes have been prepared and used to develop sensitive competitive-inhibition enzyme immunoassays. The hybridomas producing these monoclonal antibodies were obtained by fusing P3X63Ag8.653 plasmacytoma cells and splenocytes from mice hyperimmunized with keyhole limpet hemocyanin-7-succinyltaxol or -7-succinylbaccatin III conjugates. Direct and indirect competitive inhibition enzyme immunoassays were developed with these monoclonal antibodies and microtiter plates coated with bovine serum albumin conjugates of the complementary hapten. Detection limits for the direct competitive inhibition enzyme immunoassays, conducted in buffer containing 10% MeOH, were 0.6 nM taxol for 3C6 (anti-taxol); 1.1 nM baccatin III for 3H5 (anti-baccatin III); and 0.6 nM taxol or baccatin III for 8A10 (anti-taxane). The immunoassays accurately detected taxol, baccatin III, and "total taxanes" in crude MeOH extracts of Taxus brevifolia bark and in hplc fractions of these extracts. PMID:7561893

Grothaus, P G; Bignami, G S; O'Malley, S; Harada, K E; Byrnes, J B; Waller, D F; Raybould, T J; McGuire, M T; Alvarado, B

1995-07-01

230

Cremophor-Induced Lupus Erythematosus-Like Reaction with Taxol Administration: A Case Report and Review of the Literature  

PubMed Central

We report the first case of Cremophor EL-induced cutaneous lupus erythematosus-like reaction in a 40-year-old female undergoing treatment for breast cancer. There have been four reported cases of paclitaxel- and four cases of docetaxel-induced cutaneous lupus reactions in the published literature [Dasanu and Alexandrescu: South Med J 2008;101:1161–1162; Adachi and Horikawa: J Dermatol 2007;34:473–476; Lortholary et al: Presse Med 2007;36:1207–1208; Chen et al: J Rheumatol 2004;31:818–820]. Our patient developed findings of a cutaneous lupus-like reaction with administration of paclitaxel which was subsequently discontinued. She was re-challenged with albumin-bound paclitaxel which has no Cremophor EL compound in its formulation. This administration of albumin-bound paclitaxel did not induce further reaction. She did not develop a cutaneous lupus erythematosus-like reaction with three other subsequent administrations of albumin-bound paclitaxel. The diagnosis of lupus-like reaction in our patient was made based on the development of a malar butterfly rash sparing the nasolabial folds, the appearance of this rash in context of recently receiving treatments with paclitaxel, resolution of the rash after discontinuing the paclitaxel, and the presence of autoimmune antibodies in the patient's serum which resolved with discontinuation of the paclitaxel. This is the first case demonstrating that the cause of the cutaneous lupus erythematosus-like reaction is not likely due to the taxane component of paclitaxel but the chemical composition of Cremophor EL. If the chemotherapeutic agent was causing the reaction then the same reaction should be seen by albumin-bound paclitaxel. We propose that previously reported lupus reactions may actually be due to Cremophor EL, which consists of polyoxyethylated castor oil, and not the chemotherapeutic agent itself.

Pham, Anthony Q.; Berz, David; Karwan, Patricia; Colvin, Gerald A.

2011-01-01

231

Epstein-Barr Virus (EBV) Genome and Expression in Breast Cancer Tissue: Effect of EBV Infection of Breast Cancer Cells on Resistance to Paclitaxel (Taxol)  

Microsoft Academic Search

The Epstein-Barr virus (EBV) has been detected in subsets of breast cancers. In order to elaborate on these observations, we quantified by real-time PCR (Q-PCR) the EBV genome in biopsy specimens of breast cancer tissue as well as in tumor cells isolated by microdissection. Our findings show that EBV genomes can be detected by Q-PCR in about half of tumor

Hratch Arbach; Viktor Viglasky; Florence Lefeu; Jean-Marc Guinebretiere; Vanessa Ramirez; Nadege Bride; Nadia Boualaga; Thomas Bauchet; Jean-Philippe Peyrat; Marie-Christine Mathieu; Samia Mourah; Marie-Pierre Podgorniak; Jean-Marie Seignerin; Kenzo Takada; Irene Joab

2006-01-01

232

Therapeutic Angiogenesis Inhibits or Rescues Chemotherapy-induced Peripheral Neuropathy: Taxol and Thalidomide-induced Injury of Vasa Nervorum is Ameliorated by VEGF  

Microsoft Academic Search

Toxic neuropathy represents an important clinical problem in the use of the chemotherapeutic substances Taxol and thalidomide. Sensory neuropathy has a high incidence, lacks an effective treatment and is the dose-limiting factor for these drugs. The pathogenic basis of these neuropathies is unknown. We investigated the hypothesis that the experimental toxic neuropathies from Taxol and thalidomide results from destruction of

Rudolf Kirchmair; Anne B Tietz; Eleftheria Panagiotou; Dirk H Walter; Marcy Silver; Young-Sup Yoon; Peter Schratzberger; Alberto Weber; Kengo Kusano; David H Weinberg; Allan H Ropper; Jeffrey M Isner; Douglas W Losordo

2007-01-01

233

Identification of a novel function of TWIST, a bHLH protein, in the development of acquired taxol resistance in human cancer cells  

Microsoft Academic Search

Taxol is one of the widely used chemotherapeutic drugs against many types of human cancer. While it is considered as one of the most effective anticancer drugs, treatment failure often occurs due to development of acquired resistance. Therefore, it is important to understand the molecular mechanisms responsible for the development of drug resistance. Although it is generally believed that taxol

Xianghong Wang; Ming Tat Ling; Xin-Yuan Guan; Sai Wah Tsao; Hiu Wing Cheung; Davy Tak Lee; Yong Chuan Wong; X Wang

2004-01-01

234

Lyoprotected nanosphere formulations for paclitaxel controlled delivery.  

PubMed

The preparation and technological characterization of nanosphere formulations (NS) containing the anticancer drug paclitaxel (PTX) are reported. Poly(lactide) (PLA) and poly(lactide-co-glycolide) (PLGA) nanospheres (NS) were prepared by a solvent displacement method. They showed a mean particle size in the range 150-300 nm, with a high homogeneity (polydispersity index < 0.3). For long term stability, NS require additional procedures, such as freeze-drying. In this study, the effect on NS particle size and surface charge of different lyoprotectants (mono- and disaccharides, polyalcohols, and hydroxypropyl-beta-cyclodextrin) at various concentrations was tested by means of light scattering size analysis. The formulations freeze-dried with the addition of 10% glucose (w/v) showed interesting characteristics after freeze-drying. They were chosen for specific studies on drug encapsulation efficiency, in vitro drug release and biological activity on the human anaplastic thyroid carcinoma cell line 8305C. The PLGA NS, in particular, showed a cell growth inhibitory activity comparable to the free drug. PMID:17048526

Musumeci, T; Vicari, L; Ventura, C A; Gulisano, M; Pignatello, R; Puglisi, G

2006-01-01

235

Self-assembled poly(butadiene)-b-poly(ethylene oxide) polymersomes as paclitaxel carriers.  

PubMed

In this work, self-assembled poly(butadiene)-b-poly(ethylene oxide) (PB-PEO) polymersomes (polymer vesicles) and worm micelles were evaluated as paclitaxel carriers. Paclitaxel was successfully incorporated into PB-PEO polymersomes and worm micelles. The loading capacity of paclitaxel inside PB-PEO colloids ranged from 6.7% to 13.7% w/w, depending on the morphology of copolymer colloids and the molecular weight of diblock copolymer. Paclitaxel loaded OB4 (PB219-PEO121) polymersome formulations were colloidally stable for 4 months at 4 degrees C and exhibited slow steady release of paclitaxel over a 5 week period at 37 degrees C. Evaluation of the in vitro cytotoxicity of paclitaxel-polymersome formulations showed that the ability of paclitaxel-loaded polymersomes to inhibit proliferation of MCF-7 human breast cancer cells was less compared to paclitaxel alone. By increasing the concentration of paclitaxel in polymersomes from 0.02 to 0.2 mug/mL, paclitaxel-polymersome formulations showed comparable activity in inhibiting the growth of MCF-7 cells. Taken together, these results demonstrate that paclitaxel-polymersomes have desirable restrained release profile and exhibit long-term stability. PMID:17269699

Li, Shuliang; Byrne, Belinda; Welsh, Joellen; Palmer, Andre F

2007-01-01

236

Cytotoxicity of liposomal Paclitaxel in breast cancer cell line mcf-7.  

PubMed

Regarding that the breast cancer is the most prevalent disease among women, paclitaxel, an anti-cancer drug, could be used in treatment of this disease. As paclitaxel has adverse effects, it was used of nanoliposome drug delivery technology in order to reduce adverse effects and improve drug efficacy. Certain ratios of phosphatidylcholine, cholesterol and paclitaxel were synthesized to prepare nanoliposomal paclitaxel. Using Zeta sizer device, the mean diameter of nanoliposomal paclitaxel was obtained 421.4 nm and its encapsulation efficiency was 91.3 %. By dialysis, drug release in nanoliposome paclitaxel formulation within 28 h was studied which was 5.53 %. This study showed that cytotoxicity effect of nanoliposomal paclitaxel is more than that of the standard form. PMID:24426237

Esfahani, Maedeh Koohi Moftakhari; Alavi, Seyed Ebrahim; Movahedi, Fatemeh; Alavi, Fatemeh; Akbarzadeh, Azim

2013-10-01

237

The potential of Pluronic polymeric micelles encapsulated with paclitaxel for the treatment of melanoma using subcutaneous and pulmonary metastatic mice models.  

PubMed

The increasing global incidence of malignant melanoma combined with the poor prognosis and low survival rates of patients necessitates the development of new chemotherapeutic strategies. Thus, the objective of this present study was to investigate the therapeutic efficacy of Pluronic polymeric micelles encapsulating paclitaxel (PTX) in both B16F10 melanoma subcutaneous mice model and pulmonary metastatic mice model. Herein, we developed a PTX-loaded polymeric micelles (PF-PTX) consisting of Pluronic P 123 and F127 block copolymers with small particle size (?25 nm), high encapsulation efficiency (>90%), good stability in lyophilized form and pH-dependent in vitro release. Furthermore, influence of PF-PTX on in vitro cytotoxicity was determined by MTT assay using B16F10 melanoma cell line, while cellular distribution of PF-PTX was detected by confocal microscopy. Additionally, C57BL/6 mice bearing subcutaneous or pulmonary B16F10 melanoma tumors were treated with Taxol or PF-PTX, and antitumor effect was compared. It was found that antitumor efficacy of PF-PTX in both tumor models showed significant tumor growth delay and increased survival. In summary, the simple Pluronic-based nanocarrier could be harnessed for the delivery of anticancer drug to melanoma, with increased therapeutic index. PMID:21596432

Zhang, Wei; Shi, Yuan; Chen, Yanzuo; Hao, Junguo; Sha, Xianyi; Fang, Xiaoling

2011-09-01

238

SPARC independent drug delivery and antitumour effects of nab-paclitaxel in genetically engineered mice  

PubMed Central

Design Pharmacokinetic and pharmacodynamic parameters of cremophor-paclitaxel, nab-paclitaxel (human-albumin-bound paclitaxel, Abraxane) and a novel mouse-albumin-bound paclitaxel (m-nab-paclitaxel) were evaluated in genetically engineered mouse models (GEMMs) by liquid chromatography-tandem mass spectrometry (LC-MS/MS), histological and biochemical analysis. Preclinical evaluation of m-nab-paclitaxel included assessment by three-dimensional high-resolution ultrasound and molecular analysis in a novel secreted protein acidic and rich in cysteine (SPARC)-deficient GEMM of pancreatic ductal adenocarcinoma (PDA). Results nab-Paclitaxel exerted its antitumoural effects in a dose-dependent manner and was associated with less toxicity compared with cremophor-paclitaxel. SPARC nullizygosity in a GEMM of PDA, KrasG12D;p53flox/?;p48Cre (KPfC), resulted in desmoplastic ductal pancreas tumours with impaired collagen maturation. Paclitaxel concentrations were significantly decreased in SPARC null plasma samples and tissues when administered as low-dose m-nab-paclitaxel. At the maximally tolerated dose, SPARC deficiency did not affect the intratumoural paclitaxel concentration, stromal deposition and the immediate therapeutic response. Conclusions nab-Paclitaxel accumulates and acts in a dose-dependent manner. The interaction of plasma SPARC and albumin-bound drugs is observed at low doses of nab-paclitaxel but is saturated at therapeutic doses in murine tumours. Thus, this study provides important information for future preclinical and clinical trials in PDA using nab-paclitaxel in combination with novel experimental and targeted agents.

Neesse, Albrecht; Frese, Kristopher K; Chan, Derek S; Bapiro, Tashinga E; Howat, William J; Richards, Frances M; Ellenrieder, Volker; Jodrell, Duncan I; Tuveson, David A

2014-01-01

239

Primary chemotherapy with gemcitabine, epirubicin and taxol (GET) in operable breast cancer: a phase II study.  

PubMed

This trial was conducted to assess the activity and tolerability of the gemcitabine, epirubicin, taxol triplet combination in patients with operable breast cancer. After core biopsy, 43 women with stage II-IIIA breast cancer were treated with gemcitabine 1000 mg m(-2) over 30 min on days 1 and 4, epirubicin 90 mg m(-2) as an intravenous bolus on day 1, and taxol 175 mg m(-2) as a 3-h infusion on day 1, every 21 days for four cycles. The primary end point was the percentage of pathological complete responses (pCR) in the breast; secondary end points were tolerability, clinical response rates, overall and progression-free survival, tumour biomarkers before and after primary chemotherapy (PCT). All patients were included in safety and survival analyses; 41 eligible patients were evaluated for response. The overall clinical response rate was 87.8% (95% CI 77.8-97.8), with 26.8% complete responses (95% CI 13.3-40.3). A pCR in the breast was observed in six patients (14.6%; 95% CI 3.8-25.4); 15 patients (36.6%; 95% CI 21.9-51.3) had negative axillary lymph nodes. Grade 4 neutropenia was observed in 67.4% of the patients; febrile neutropenia occurred in 1.9% of cycles (granulocyte colony-stimulating factor was used in 3.2% of the cycles to shorten the duration of neutropenia). A statistically significant difference between Mib-1 at baseline (> or =20% in 71.4% of the patients) and at definitive surgery (28.6%, P < 0.05) was observed. The gemcitabine, epirubicin, taxol regimen is active and well tolerated as PCT for operable breast cancer. This combination allows the administration of full doses of active agents with a low incidence of febrile neutropenia. PMID:16052214

Conte, P F; Donati, S; Gennari, A; Guarneri, V; Orlandini, C; Rondini, M; Roncella, M; Marini, L; Collecchi, P; Viacava, P; Naccarato, A G; Degli Esposti, R; Bonardi, S; Bottini, A; Saracchini, S; Tumolo, S; Gullo, G; Santoro, A; Crino, L

2005-08-22

240

Primary chemotherapy with gemcitabine, epirubicin and taxol (GET) in operable breast cancer: a phase II study  

PubMed Central

This trial was conducted to assess the activity and tolerability of the gemcitabine, epirubicin, taxol triplet combination in patients with operable breast cancer. After core biopsy, 43 women with stage II–IIIA breast cancer were treated with gemcitabine 1000?mg?m?2 over 30?min on days 1 and 4, epirubicin 90?mg?m?2 as an intravenous bolus on day 1, and taxol 175?mg?m?2 as a 3-h infusion on day 1, every 21 days for four cycles. The primary end point was the percentage of pathological complete responses (pCR) in the breast; secondary end points were tolerability, clinical response rates, overall and progression-free survival, tumour biomarkers before and after primary chemotherapy (PCT). All patients were included in safety and survival analyses; 41 eligible patients were evaluated for response. The overall clinical response rate was 87.8% (95% CI 77.8–97.8), with 26.8% complete responses (95% CI 13.3–40.3). A pCR in the breast was observed in six patients (14.6%; 95% CI 3.8–25.4); 15 patients (36.6%; 95% CI 21.9–51.3) had negative axillary lymph nodes. Grade 4 neutropenia was observed in 67.4% of the patients; febrile neutropenia occurred in 1.9% of cycles (granulocyte colony-stimulating factor was used in 3.2% of the cycles to shorten the duration of neutropenia). A statistically significant difference between Mib-1 at baseline (?20% in 71.4% of the patients) and at definitive surgery (28.6%, P<0.05) was observed. The gemcitabine, epirubicin, taxol regimen is active and well tolerated as PCT for operable breast cancer. This combination allows the administration of full doses of active agents with a low incidence of febrile neutropenia.

Conte, P F; Donati, S; Gennari, A; Guarneri, V; Orlandini, C; Rondini, M; Roncella, M; Marini, L; Collecchi, P; Viacava, P; Naccarato, A G; Degli Esposti, R; Bonardi, S; Bottini, A; Saracchini, S; Tumolo, S; Gullo, G; Santoro, A; Crino, L

2005-01-01

241

Biodistribution of paclitaxel and poly( l -glutamic acid)-paclitaxel conjugate in mice with ovarian OCa1 tumor  

Microsoft Academic Search

Purpose: Poly(l-glutamic acid)-paclitaxel (PG-TXL) is a water-soluble paclitaxel (TXL) conjugate made by conjugating TXL to poly(l-glutamic acid) via ester bonds. In preclinical studies, PG-TXL has shown significant antitumor activity against a variety\\u000a of solid tumors. To elucidate the relationship between tissue distribution and antitumor efficacy of PG-TXL, we studied and\\u000a compared the biodistribution of PG-TXL and TXL. Methods: Female C3Hf\\/Kam

Chun Li; Robert A. Newman; Qing-Ping Wu; Shi Ke; Wei Chen; Toni Hutto; Zuxing Kan; Melvin D. Brannan; Chusilp Charnsangavej; Sidney Wallace

2000-01-01

242

Janus nanogels of PEGylated Taxol and PLGA-PEG-PLGA copolymer for cancer therapy  

NASA Astrophysics Data System (ADS)

Nanogels are promising carriers for the delivery of anti-cancer drugs for cancer therapy. We report in this study on a Janus nanogel system formed by mixing a prodrug of Taxol (PEGylated Taxol) and a copolymer of PLGA-PEG-PLGA. The Janus nanogels have good stability over months in aqueous solutions and the freeze-dried powder of nanogels can be re-dispersed instantly in aqueous solutions. The Janus nanogels show an enhanced inhibition effect on tumor growth in a mice breast cancer model probably due to the enhanced uptake of the nano-sized materials by the EPR effect. What is more, the nanogels can also serve as physical carriers to co-deliver other anti-cancer drugs such as doxorubicin to further improve the anti-cancer efficacy. The results obtained from H&E staining and TUNEL assay also support the observation of tumor growth inhibition. These results suggest the potential of this novel delivery system for cancer therapy.Nanogels are promising carriers for the delivery of anti-cancer drugs for cancer therapy. We report in this study on a Janus nanogel system formed by mixing a prodrug of Taxol (PEGylated Taxol) and a copolymer of PLGA-PEG-PLGA. The Janus nanogels have good stability over months in aqueous solutions and the freeze-dried powder of nanogels can be re-dispersed instantly in aqueous solutions. The Janus nanogels show an enhanced inhibition effect on tumor growth in a mice breast cancer model probably due to the enhanced uptake of the nano-sized materials by the EPR effect. What is more, the nanogels can also serve as physical carriers to co-deliver other anti-cancer drugs such as doxorubicin to further improve the anti-cancer efficacy. The results obtained from H&E staining and TUNEL assay also support the observation of tumor growth inhibition. These results suggest the potential of this novel delivery system for cancer therapy. Electronic supplementary information (ESI) available: Synthesis and characterization of compounds, dynamic time sweep, H&E result and body weight change of mice. See DOI: 10.1039/c3nr02937a

Wei, Jun; Wang, Huaimin; Zhu, Meifeng; Ding, Dan; Li, Dongxia; Yin, Zhinan; Wang, Lianyong; Yang, Zhimou

2013-09-01

243

Molecular simulations of Taxawallin I inside classical taxol binding site of ?-tubulin.  

PubMed

A new taxoid Taxawallin I (1) along with two known taxoids (2-3) were isolated from methanolic bark extract of Taxus wallichiana Zucc. Structural characterization was confirmed by mass and NMR spectral techniques. Taxawallin I exhibited significant in-vitro anticancer activity against HepG2, A498, NCI-H226 and MDR 2780AD cancer lines. Tubulin binding assay was performed to assess its tubulin binding activity. Molecular docking analysis was performed to study the potential binding mode inside the taxol binding site of ?-tubulin. PMID:20969934

Khan, Inamullah; Nisar, Muhammad; Ahmad, Manzoor; Shah, Hamidullah; Iqbal, Zafar; Saeed, Muhammad; Halimi, Syed Muhammad Ashhad; Kaleem, Waqar Ahmad; Qayum, Mughal; Aman, Akhter; Abdullah, Syed Muhammad

2011-03-01

244

Paclitaxel induces neurotoxicity through endoplasmic reticulum stress.  

PubMed

Due to chemotherapy, the majority of breast cancer patients survive, but frequently complain of chemotherapy-associated cognitive impairment. This phenomenon is termed "chemobrain" or "chemofog" in the literature. However, its mechanisms are unclear. The objective of this study was to investigate the mechanisms of paclitaxel (Px)-induced neurotoxicity, with a focus on endoplasmic reticulum (ER) stress. To investigate Px-induced neurotoxicity and ER stress induction, SK-N-SH cells were treated with 1, 10, 50, and 100 ?M Px for 24 h. Neurotoxicity was assessed using MTS viability assays, and ER stress was assessed by evaluating the expression of phosphorylated elF2? (phospho-eIF2?), C/EBP homologous protein (CHOP), and cleaved caspase 4 and caspase 3 (the active form of each caspase). Furthermore, to investigate whether immunoglobulin heavy-chain binding protein (BiP) inducer X (BIX), which induces the molecular chaperone BiP, could attenuate Px-induced neurotoxicity, SK-N-SH cells were pre-treated for 12 h with 3.5 ?M BIX before Px treatment. Neurotoxicity was observed in SK-N-SH cells treated with Px in a dose-dependent manner compared with vehicle control. Furthermore, phospho-eIF2?, CHOP, and activated caspase 4 and caspase 3 were significantly induced in Px-treated cells. In addition, pre-treatment with BIX significantly attenuated the induction of CHOP and activated caspase 4 and caspase 3. The viability of BIX pre-treated cells prior to Px treatment was significantly increased compared with cells that were not treated with BIX. Our results suggest that Px induces neurotoxicity in part through activating the ER stress response. Our findings should contribute to novel approaches regarding the mechanism of Px-induced neurotoxicity, including chemobrain. PMID:23806691

Tanimukai, Hitoshi; Kanayama, Daisuke; Omi, Tsubasa; Takeda, Masatoshi; Kudo, Takashi

2013-07-19

245

Functionalized nanospheres for targeted delivery of paclitaxel.  

PubMed

Targeted delivery of anti-cancer agents to cancer cells is a mature line of investigation that has yet to realize its full potential. In this study we report on the development of a delivery platform with the future goal of merging two thus far parallel methods for selective elimination of cancer cells: targeted nanospheres and pretargeted radioimmunotherapy. Several clinical trials have shown the promise of pretargeted radioimmunotherapy, which leverages the specificity of antibodies for targeted cell populations and delivers a localized dose of a biotinylated radionuclide that is most often administered following binding of a biotinylated antibody and streptavidin (StA) to the target cells. The work presented here describes the development of biotinylated nanospheres based on an ABA-type copolymer comprised of a tyrosine-derived oligomer as the B-block and poly(ethylene glycol) (PEG) A-blocks. The biotinylated nanospheres encapsulate paclitaxel (PTX) to the same extent as unbiotinylated nanospheres. Efficacy of targeting was shown on CD44 positive cells in the SUM159 breast cancer cell line by incubating the cells sequentially with a biotinylated anti-CD44 antibody, StA and the biotinylated nanospheres encapsulating PTX. Targeted nanospheres achieved the half maximal inhibitory concentration of PTX on SUM159 cells at a 5-10 fold lower concentration than that of PTX applied in either non-targeted nanospheres or free drug approaches. Moreover, targeted nanospheres selectively eliminated CD44 positive SUM159 cells compared to free PTX and untargeted nanospheres. This new generation of nano-sized carrier offers a versatile platform that can be adopted for a wide variety of drug and target specific applications and has the potential to be combined with the clinically emerging method of pretargeted radioimmunotherapy. PMID:23792807

Bushman, Jared; Vaughan, Asa; Sheihet, Larisa; Zhang, Zheng; Costache, Marius; Kohn, Joachim

2013-11-10

246

Novel free paclitaxel-loaded poly(L-?-glutamylglutamine)-paclitaxel nanoparticles  

PubMed Central

The purpose of this study was to develop a novel formulation of paclitaxel (PTX) that would improve its therapeutic index. Here, we combined a concept of polymer–PTX drug conjugate with a concept of polymeric micelle drug delivery to form novel free PTX-loaded poly(L-?-glutamylglutamine) (PGG)–PTX conjugate nanoparticles. The significance of this drug formulation emphasizes the simplicity, novelty, and flexibility of the method of forming nanoparticles that contain free PTX and conjugated PTX in the same drug delivery system. The results of effectively inhibiting tumor growth in mouse models demonstrated the feasibility of the nanoparticle formulation. The versatility and potential of this dual PTX drug delivery system can be explored with different drugs for different indications. Novel and simple formulations of PTX-loaded PGG–PTX nanoparticles could have important implications in translational medicines.

Yang, Danbo; Van, Sang; Jiang, Xinguo; Yu, Lei

2011-01-01

247

Testing Dose-Dense Paclitaxel for Ovarian and Related Cancers  

Cancer.gov

In this trial, women with stage III or IV ovarian epithelial, fallopian tube, or primary peritoneal cancer will be randomly assigned to receive either standard or dose-dense paclitaxel in addition to standard carboplatin (given once every 3 weeks) and optional bevacizumab.

248

Paclitaxel induces vascular endothelial growth factor expression through reactive oxygen species production.  

PubMed

The antineoplastic drug paclitaxel is known to block cells in the G2/M phase of the cell cycle through stabilization of microtubules. The development of paclitaxel resistance in tumors is one of the most significant obstacles to successful therapy. Vascular endothelial growth factor (VEGF) and hypoxia-inducible factor 1 (HIF-1) are important regulators of neovascularization. HIF-1 regulates VEGF expression at the transcriptional level. Here, we investigated whether paclitaxel treatment affects VEGF expression for the development of paclitaxel resistance. Paclitaxel treatment induced dose-dependent cell death and increased VEGF expression. Paclitaxel also induced nuclear factor-kappaB activation and stabilized HIF-1alpha, which stimulated luciferase activity of HIF-1alpha response element on VEGF gene. As paclitaxel treatment produced reactive oxygen species (ROS), VEGF expression was increased by H2O2 treatment and reduced by various ROS scavengers such as N-acetyl-L-cysteine, pyrrolidine dithiocarbamate and diphenylene iodonium. Paclitaxel-induced cell death was aggravated by incubation with those ROS scavengers. Collectively, this suggests that paclitaxel-induced VEGF expression could be mediated by paclitaxel-induced ROS production through nuclear factor-kappaB activation and HIF-1alpha stabilization, which could affect resistance induction to antitumor therapeutics during cancer treatment. PMID:18322419

Kim, Hyun Sun; Oh, Jin Mi; Jin, Dong Hoon; Yang, Kyu-Hwan; Moon, Eun-Yi

2008-01-01

249

Masitinib antagonizes ATP-binding cassette subfamily C member 10-mediated paclitaxel resistance: a preclinical study.  

PubMed

Paclitaxel displays clinical activity against a wide variety of solid tumors. However, resistance to paclitaxel significantly attenuates the response to chemotherapy. The ABC transporter subfamily C member 10 (ABCC10), also known as multidrug resistance protein 7 (MRP7) efflux transporter, is a major mediator of paclitaxel resistance. In this study, we show that masitinib, a small molecule stem-cell growth factor receptor (c-Kit) tyrosine kinase inhibitor, at nontoxic concentrations, significantly attenuates paclitaxel resistance in HEK293 cells transfected with ABCC10. Our in vitro studies indicated that masitinib (2.5 ?mol/L) enhanced the intracellular accumulation and decreased the efflux of paclitaxel by inhibiting the ABCC10 transport activity without altering the expression level of ABCC10 protein. Furthermore, masitinib, in combination with paclitaxel, significantly inhibited the growth of ABCC10-expressing tumors in nude athymic mice in vivo. Masitinib administration also resulted in a significant increase in the levels of paclitaxel in the plasma, tumors, and lungs compared with paclitaxel alone. In conclusion, the combination of paclitaxel and masitinib could serve as a novel and useful therapeutic strategy to reverse paclitaxel resistance mediated by ABCC10. PMID:24431074

Kathawala, Rishil J; Sodani, Kamlesh; Chen, Kang; Patel, Atish; Abuznait, Alaa H; Anreddy, Nagaraju; Sun, Yue-Li; Kaddoumi, Amal; Ashby, Charles R; Chen, Zhe-Sheng

2014-03-01

250

Evaluation of lercanidipine in Paclitaxel-induced neuropathic pain model in rat: a preliminary study.  

PubMed

Objective. To demonstrate the antinociceptive effect of lercanidipine in paclitaxel-induced neuropathy model in rat. Materials and Methods. A total of 30 rats were divided into five groups of six rats in each group as follows: Gr I: 0.9% NaCl, Gr II: paclitaxel?+?0.9% NaCl, Gr III: paclitaxel?+?lercanidipine 0.5??g/kg, Gr IV: paclitaxel?+?lercanidipine 1??g/kg, and Gr V: paclitaxel?+?lercanidipine 2.5??g/kg. Paclitaxel-induced neuropathic pain in rat was produced by single intraperitoneal (i.p.) injection of 1?mg/kg of paclitaxel on four alternate days (0, 2, 4, and 6). The tail flick and cold allodynia methods were used for assessing the pain threshold, and the assessments were done on days 0 (before first dose of paclitaxel) and on days 7, 14, 21, and 28. Results. There was a significant decrease (P < 0.001) in the tail flick and cold allodynia latency in the paclitaxel-alone group from day 14 onward when compared with day 0. In the lercanidipine groups, the decrease in the tail flick and cold allodynia latency was not observed in 1.0 and 2.5??g/kg groups and it was statistically significant (P < 0.01) when compared with paclitaxel-alone group. PMID:22550574

Saha, Lekha; Hota, Debasish; Chakrabarti, Amitava

2012-01-01

251

Nab-paclitaxel for the treatment of breast cancer: efficacy, safety, and approval  

PubMed Central

Nanoparticle albumin-bound paclitaxel (nab-paclitaxel) is a novel formulation of paclitaxel that does not require solvents such as polyoxyethylated castor oil and ethanol. Use of these solvents has been associated with toxic response, including hypersensitivity reactions and prolonged sensory neuropathy, as well as a negative impact in relation to the therapeutic index of paclitaxel. nab-paclitaxel displays greater antitumor activity and less toxicity than solvent-base paclitaxel. In a phase I trial of single nab-paclitaxel, the maximum tolerated dose was 300 mg/m2 with the dose limiting toxicities being sensory neuropathy, stomatitis, and superficial keratopathy. In the metastatic setting, a pivotal comparative randomized phase III study demonstrated that nab-paclitaxel (at 260 mg/m2 over 30 minutes infusion without premedication every 3 weeks) mediated a superior objective response rate and prolonged time to progression compared with solvent-based paclitaxel (at 175 mg/m2 over a 3-hour injection with standard premedication). The nab-paclitaxel-treated group showed a higher incidence of sensory neuropathy than the solvent-based paclitaxel group. However, these adverse side effects rapidly resolved after interruption of treatment and dose reduction. Weekly administration of nabpaclitaxel was also more active and displayed less toxicity compared with 100 mg/m2 docetaxel given triweekly. Nab-paclitaxel has already been approved in 42 countries for the treatment of metastatic breast cancer previously treated with anthracycline, based on confirmation of the efficacy and manageable toxicity in the metastatic setting. This review summarizes the most relevant knowledge on nab-paclitaxel for treating breast cancer in terms of clinical usefulness including efficacy and safety of this new agent.

Yamamoto, Yutaka; Kawano, Ichiro; Iwase, Hirotaka

2011-01-01

252

Radiosensitization of malignant gliomas following intracranial delivery of paclitaxel biodegradable polymer microspheres.  

PubMed

Object The aim of this study was to demonstrate that paclitaxel could function as a radiosensitizer for malignant glioma in vitro and in vivo. Methods The radiosensitizing effect of paclitaxel was tested in vitro using the human U373MG and rat 9L glioma cell lines. Cell cycle arrest in response to paclitaxel exposure was quantified by flow cytometry. Cells were subsequently irradiated, and toxicity was measured using the clonogenic assay. In vivo studies were performed in Fischer 344 rats implanted with intracranial 9L gliosarcoma. Rats were treated with control polymer implants, paclitaxel controlled-release polymers, radiotherapy, or a combination of the 2 treatments. The study end point was survival. Results Flow cytometry demonstrated G2-M arrest in both U373MG and 9L cells following 6-12 hours of paclitaxel exposure. The order in which the combination treatment was administered was significant. Exposure to radiation treatment (XRT) during the 6-12 hours after paclitaxel treatment resulted in a synergistic reduction in colony formation. This effect was greater than the effect from either treatment alone and was also greater than the effect of radiation exposure followed by paclitaxel. Rats bearing 9L gliosarcoma tumors treated with paclitaxel polymer administration followed by single-fraction radiotherapy demonstrated a synergistic improvement in survival compared with any other treatment, including radiotherapy followed by paclitaxel treatment. Median survival for control animals was 13 days; for those treated with paclitaxel alone, 21 days; for those treated with XRT alone, 21 days; for those treated with XRT followed by paclitaxel, 45 days; and for those treated with paclitaxel followed by XRT, more than 150 days (p < 0.0001). Conclusions These results indicate that paclitaxel is an effective radiosensitizer for malignant gliomas because it renders glioma cells more sensitive to ionizing radiation by causing G2-M arrest, and induces a synergistic response to chemoradiotherapy. PMID:24605841

Gabikian, Patrik; Tyler, Betty M; Zhang, Irma; Li, Khan W; Brem, Henry; Walter, Kevin A

2014-05-01

253

Aprepitant  

MedlinePLUS

... Gleevec), irinotecan (Camptosar), paclitaxel (Taxol), tamoxifen (Nolvadex), vinblastine, vincristine (Vincasar), and vinorelbine (Navelbine); carbamazepine (Tegretol); clarithromycin (Biaxin); ...

254

Idiotypic mimicry and the assembly of a supramolecular structure: an anti-idiotypic antibody that mimics taxol in its tubulin-microtubule interactions.  

PubMed Central

Taxol, originally extracted from the bark of the western yew, Taxus brevifolia, is reportedly the first of a new class of anti-cancer agents. It acts by promoting and irreversibly stabilizing microtubule assembly, thus interfering with the dynamic processes required for cell viability and multiplication. With the aim of using immunological techniques to study the mechanism of action of taxol, a monoclonal anti-idiotypic antibody that mimics taxol was prepared, using an auto-anti-idiotypic strategy. It and its Fab fragment inhibited the binding of [3H]taxol to microtubules. Moreover, like taxol, both promoted the assembly of tubulin into microtubules. These findings provide an example of an anti-idiotypic antibody capable of assembling an organized supramolecular structure from soluble cellular components. In addition, it further establishes the ability of anti-idiotypic antibodies to be functional mimics of ligand molecules bearing no structural similarity to immunoglobulins. The variable regions of the antibody have been sequenced. With the exception of the complementarity-determining region 3, the sequence of the heavy chain variable region is strikingly similar to that of an anti-idiotypic antibody raised to anti-insulin. The finding that a polypeptide can mimic taxol raises the possibility that taxol acts as a peptidomimetic compound that interferes with the function of an endogenous polypeptide. Images

Leu, J G; Chen, B X; Diamanduros, A W; Erlanger, B F

1994-01-01

255

Nab-paclitaxel monotherapy in refractory pancreatic adenocarcinoma  

PubMed Central

Background The standard of care in patients with metastatic pancreatic adenocarcinoma is undefined beyond second line of treatment. There have been scant reports of benefit from nab-paclitaxel in patients with refractory pancreatic cancer. Materials and methods A retrospective review was carried out in patients with pancreatic adenocarcinoma at Siteman Cancer Center, who had received nab-paclitaxel monotherapy after experiencing disease progression on standard treatments. Nab-paclitaxel was given either two out of every three weeks or three out of every four weeks. Results Twenty patients were identified and included for data analysis. Median age was 63.5 years old. All patients had previously received gemcitabine, while 40% had also received FOLFIRINOX. Median number of prior lines of systemic treatment was 2. Patients were treated for a median of 15 weeks, with a range of 1 to 41.7 weeks. Median dose of nab-paclitaxel was 100 mg/m2 with range of 75-125 mg/m2. Best response imaging was available in 17 patients and 11 out of the 17 patients (64.7%) had stable disease. Median progression-free survival (PFS) was 3.7 months and overall survival (OS) were 5.2 months. Most common treatment related toxicities included grade 1 pneumonitis in five patients (25%), grade 3 or 4 neutropenia in three patients (15%), and dehydration resulting in hospitalization in one patient (5%). Conclusions Nab-paclitaxel monotherapy had acceptable level of toxicity in a heavily pretreated patient population with pancreatic cancer and appeared to provide a clinical benefit. This agent is worthy of further prospective studies to evaluate extent of benefit after standard therapies have failed.

Peddi, Parvin F.; Cho, May; Wang, Jian; Gao, Feng

2013-01-01

256

Transformation of taxol-stabilized microtubules into inverted tubulin tubules triggered by a tubulin conformation switch  

PubMed Central

Bundles of taxol-stabilized microtubules (MTs) – hollow tubules comprised of assembled ??-tubulin heterodimers – spontaneously assemble above a critical concentration of tetravalent spermine and are stable over long times at room temperature. Here we report that at concentrations of spermine several-fold higher the MT bundles (BMT) quickly become unstable and undergo a shape transformation to bundles of inverted tubulin tubules (BITT), the outside surface of which corresponds to the inner surface of the BMT tubules. Using transmission electron microscopy and synchrotron small-angle x-ray scattering, we quantitatively determined both the nature of the BMT to BITT transformation pathway, which results from a spermine-triggered conformation switch from straight to curved in the constituent taxol-stabilized tubulin oligomers, and the structure of the BITT phase, which is formed of tubules of helical tubulin oligomers. Inverted tubulin tubules provide a platform for studies requiring exposure and availability of the inside, luminal surface of MTs to MT-targeted-drugs and MT-associated-proteins.

Ginsburg, Avi; Kohl, Phillip A.; Li, Youli; Miller, Herbert P.; Wilson, Leslie; Raviv, Uri; Choi, Myung Chul; Safinya, Cyrus R.

2014-01-01

257

Radial Compression of Microtubules and the Mechanism of Action of Taxol and Associated Proteins  

PubMed Central

Microtubules (MTs) are hollow cylindrical polymers composed of ??-tubulin heterodimers that align head-to-tail in the MT wall, forming linear protofilaments that interact laterally. We introduce a probe of the interprotofilament interactions within MTs and show that this technique gives insight into the mechanisms by which MT-associated proteins (MAPs) and taxol stabilize MTs. In addition, we present further measurements of the mechanical properties of MT walls, MT-MT interactions, and the entry of polymers into the MT lumen. These results are obtained from a synchrotron small angle x-ray diffraction (SAXRD) study of MTs under osmotic stress. Above a critical osmotic pressure, Pcr, we observe rectangular bundles of MTs whose cross sections have buckled to a noncircular shape; further increases in pressure continue to distort MTs elastically. The Pcr of ?600 Pa provides, for the first time, a measure of the bending modulus of the interprotofilament bond within an MT. The presence of neuronal MAPs greatly increases Pcr, whereas surprisingly, the cancer chemotherapeutic drug taxol, which suppresses MT dynamics and inhibits MT depolymerization, does not affect the interprotofilament interactions. This SAXRD-osmotic stress technique, which has enabled measurements of the mechanical properties of MTs, should find broad application for studying interactions between MTs and of MTs with MAPs and MT-associated drugs.

Needleman, Daniel J.; Ojeda-Lopez, Miguel A.; Raviv, Uri; Ewert, Kai; Miller, Herbert P.; Wilson, Leslie; Safinya, Cyrus R.

2005-01-01

258

Janus nanogels of PEGylated Taxol and PLGA-PEG-PLGA copolymer for cancer therapy.  

PubMed

Nanogels are promising carriers for the delivery of anti-cancer drugs for cancer therapy. We report in this study on a Janus nanogel system formed by mixing a prodrug of Taxol (PEGylated Taxol) and a copolymer of PLGA-PEG-PLGA. The Janus nanogels have good stability over months in aqueous solutions and the freeze-dried powder of nanogels can be re-dispersed instantly in aqueous solutions. The Janus nanogels show an enhanced inhibition effect on tumor growth in a mice breast cancer model probably due to the enhanced uptake of the nano-sized materials by the EPR effect. What is more, the nanogels can also serve as physical carriers to co-deliver other anti-cancer drugs such as doxorubicin to further improve the anti-cancer efficacy. The results obtained from H&E staining and TUNEL assay also support the observation of tumor growth inhibition. These results suggest the potential of this novel delivery system for cancer therapy. PMID:23982346

Wei, Jun; Wang, Huaimin; Zhu, Meifeng; Ding, Dan; Li, Dongxia; Yin, Zhinan; Wang, Lianyong; Yang, Zhimou

2013-10-21

259

Human cancer cell line microRNAs associated with in vitro sensitivity to paclitaxel  

PubMed Central

Paclitaxel is a mainstay of treatment for many solid tumors, and frequently, clinical outcome is influenced by paclitaxel sensitivity. Despite this, our understanding of the molecular basis of paclitaxel response is incomplete. Recently, it has been shown that microRNAs (miRNAs) influence messenger RNA (mRNA) transcriptional control and can contribute to human carcinogenesis. In the present study, our objective was to identify miRNAs associated with cancer cell line response to paclitaxel and to evaluate these miRNAs as therapeutic targets to increase paclitaxel sensitivity. We measured the expression of 335 unique miRNAs in 40 human cancer cell lines selected from the NCI panel. We then integrated miRNA expression data with publicly available paclitaxel-sensitivity (GI50) data for each of the 40 cell lines to identify miRNAs associated with paclitaxel sensitivity. Ovarian cancer cell lines with differential miRNA expression and paclitaxel sensitivity were transiently transfected with miRNA precursors and inhibitors, and the effects on in vitro cell paclitaxel sensitivity were evaluated. Pearson’s correlation identified 2 miRNAs (miR-367 and miR-30a-5p) associated with the NCI40 cell line in vitro paclitaxel response (P<0.0003). Ovarian cancer cells were selected based on the association between paclitaxel sensitivity and miR-367/miR-30a-5p expression. Overexpression of miR-367 in the paclitaxel-sensitive cells [PA1; IC50, 1.69 nM, high miR-367 (2.997), low miR-30a-5p (?0.323)] further increased paclitaxel sensitivity, whereas miR-367 depletion decreased paclitaxel sensitivity. In contrast, overexpression and depletion of miR-30a-5p in the paclitaxel-resistant cells [OVCAR4; IC50, 17.8 nM, low miR-367 (?0.640), high miR-30a-5p (3.270)] decreased and increased paclitaxel sensitivity, respectively. We identified and successfully targeted miRNAs associated with human cancer cell line response to paclitaxel. Our strategy of integrating in vitro miRNA expression and drug sensitivity data may not only aid in the characterization of determinants of drug response but also in the identification of novel therapeutic targets to increase activity of existing therapeutics.

CHEN, NING; CHON, HYE SOOK; XIONG, YIN; MARCHION, DOUGLAS C.; JUDSON, PATRICIA L.; HAKAM, ARDESHIR; GONZALEZ-BOSQUET, JESUS; PERMUTH-WEY, JENNIFER; WENHAM, ROBERT M.; APTE, SACHIN M.; CHENG, JIN Q.; SELLERS, THOMAS A.; LANCASTER, JOHNATHAN M.

2014-01-01

260

Enzyme-linked immunosorbent assay for the detection and the semi-quantitative determination of taxane diterpenoids related to taxol in Taxus sp. and tissue cultures.  

PubMed

An ELISA-assay for the detection and the semi-quantitative determination of taxane diterpenoids structurally related to taxol found in Taxus sp. has been developed. The antiserum was raised in rabbits using a 2'-succinyltaxol-bovine serum albumin conjugate as immunogen. The working range of the assay was from 1 to 100 ng of taxol. In order to improve the production of taxol, preliminary experiments have been performed on crude extracts of several Taxus sp.; the results indicate that the present immunoassay is an useful tool for the rapid screening of species, varieties or individual plants out of a large population as well as for tissue cultures analysis. PMID:1680168

Jaziri, M; Diallo, B M; Vanhaelen, M H; Vanhaelen-Fastre, R J; Zhiri, A; Bécu, A G; Homes, J

1991-01-01

261

Entrapment by Cremophor EL decreases the absorption of paclitaxel from the gut  

Microsoft Academic Search

Background: Recent studies in mice and patients have shown that the low oral bioavailability of paclitaxel can be increased by coadministration of P-glycoprotein blockers. However, in patients an increase in the oral paclitaxel dose from 60 to 300 mg\\/m2 does not result in proportionally higher plasma levels. We hypothesized that the surfactant Cremophor EL, present in the formulation of paclitaxel,

Heleen A. Bardelmeijer; Mariët Ouwehand; Mirte M. Malingré; Jan H. Schellens; Jos H. Beijnen; Olaf van Tellingen

2002-01-01

262

Poly(L-glutamic acid)-paclitaxel conjugate is a potent enhancer of tumor radiocurability  

Microsoft Academic Search

Purpose: Conjugating drugs with polymeric carriers is one way to improve selective delivery to tumors. Poly (L-glutamic acid)-paclitaxel (PG-TXL) is one such conjugate. Compared with paclitaxel, its uptake, tumor retention, and antitumor efficacy are increased. Initial studies showed that PG-TXL given 24 h before or after radiotherapy enhanced tumor growth delay significantly more than paclitaxel. To determine if PG-TXL-induced enhancement

Luka Milas; Kathryn A Mason; Nancy Hunter; Chun Li; Sidney Wallace

2003-01-01

263

Combined Delivery of Paclitaxel and Tanespimycin via Micellar Nanocarriers: Pharmacokinetics, Efficacy and Metabolomic Analysis  

PubMed Central

Background Despite the promising anticancer efficacy observed in preclinical studies, paclitaxel and tanespimycin (17-AAG) combination therapy has yielded meager responses in a phase I clinical trial. One serious problem associated with paclitaxel/17-AAG combination therapy is the employment of large quantities of toxic organic surfactants and solvents for drug solubilization. The goal of this study was to evaluate a micellar formulation for the concurrent delivery of paclitaxel and 17-AAG in vivo. Methodology/Principal Findings Paclitaxel/17-AAG-loaded micelles were assessed in mice bearing human ovarian tumor xenografts. Compared with the free drugs at equivalent doses, intravenous administration of paclitaxel/17-AAG-loaded micelles led to 3.5- and 1.7-fold increase in the tumor concentrations of paclitaxel and 17-AAG, respectively, without significant altering drug levels in normal organs. The enhanced tumor accumulation of the micellar drugs was further confirmed by the whole-body near infrared imaging using indocyanine green-labeled micelles. Subsequently, the anticancer efficacy of paclitaxel/17-AAG-loaded micelles was examined in comparison with the free drugs (weekly 20 mg/kg paclitaxel, twice-weekly 37.5 mg/kg 17-AAG). We found that paclitaxel/17-AAG-loaded micelles caused near-complete arrest of tumor growth, whereas the free drug-treated tumors experienced rapid growth shortly after the 3-week treatment period ended. Furthermore, comparative metabolomic profiling by proton nuclear magnetic resonance revealed significant decrease in glucose, lactate and alanine with simultaneous increase in glutamine, glutamate, aspartate, choline, creatine and acetate levels in the tumors of mice treated with paclitaxel/17-AAG-loaded micelles. Conclusions/Significance We have demonstrated in the current wok a safe and efficacious nano-sized formulation for the combined delivery of paclitaxel and 17-AAG, and uncovered unique metabolomic signatures in the tumor that correlate with the favorable therapeutic response to paclitaxel/17-AAG combination therapy.

Wang, Yingzhe; Teng, Quincy; Tan, Chalet

2013-01-01

264

Role of Reoxygenation in Induction of Enhancement of Tumor Radioresponse by Paclitaxel1  

Microsoft Academic Search

We reported previously(L. Milas et al., Cancer Res., 54: 3506-3510, 1994)that paclitaxel greatly enhances the response of a murine mammary carcinoma to subsequent irradiation and hypothesized that the enhanced radioresponse was mediated by tumor cell reoxygenation caused by treat ment with paclitaxel. Because paclitaxel induced massive tumor cell de struction by apoptosis, it was reasoned that as apoptotic cells were

Luka Milus; Nancy R. Hunter; Kathryn A. Mason; Christopher G. Milross; Yoshihiro Saito; Lester J. Peters

265

Synthesis and Biological Evaluation of a Biotinylated Paclitaxel With an Extra-Long Chain Spacer Arm  

PubMed Central

A biotinylated paclitaxel derivative with an extra-long-chain (LC-LC-Biotin) spacer arm was synthesized using an improved synthetic reaction sequence. The biotinylated paclitaxel analogue retained excellent microtubule stabilizing activity in vitro. Furthermore, it was shown that this analogue can simultaneously engage streptavidin and the binding site on microtubules, making it suitable for localization studies or for the attachment of paclitaxel to solid substrates via a streptavidin linkage.

Lis, Lev. G.; Smart, Mary A.; Luchniak, Anna; Gupta, Mohan L.; Gurvich, Vadim J.

2012-01-01

266

Differential sensitivity of paclitaxel-induced apoptosis in human esophageal squamous cell carcinoma cell lines  

Microsoft Academic Search

Purpose: Paclitaxel is a highly effective chemotherapy agent against adenocarcinomas and squamous cell carcinomas of the esophagus.\\u000a However, its precise effects in human esophageal cancer cells are not well understood. This study was designed to examine\\u000a the relationship between cell-cycle phases of paclitaxel-activated checkpoints and to elucidate the molecular pathway of the\\u000a effect of paclitaxel in human esophageal squamous cell

Ahmad Faried; Leri S. Faried; Hitoshi Kimura; Makoto Sohda; Masanobu Nakajima; Tatsuya Miyazaki; Hiroyuki Kato; Tatsuya Kanuma; Hiroyuki Kuwano

2006-01-01

267

Effect of paclitaxel on transient receptor potential vanilloid 1 in rat dorsal root ganglion.  

PubMed

Peripheral neuropathy is a common adverse effect of paclitaxel treatment. To analyze the contribution of transient receptor potential vanilloid 1 (TRPV1) in the development of paclitaxel-induced thermal hyperalgesia, TRPV1 expression in the rat dorsal root ganglion (DRG) was analyzed after paclitaxel treatment. Behavioral assessment using the tail-flick test showed that intraperitoneal administration of 2 and 4 mg/kg paclitaxel induced thermal hyperalgesia after days 7, 14, and 21. Paclitaxel-induced thermal hyperalgesia after day 14 was significantly inhibited by the TRP antagonist ruthenium red (3 mg/kg, s.c.) and the TRPV1 antagonist capsazepine (30 mg/kg, s.c.). Paclitaxel (2 and 4 mg/kg) treatment increased the expression of TRPV1 mRNA and protein in DRG neurons. Immunohistochemistry showed that paclitaxel (4 mg/kg) treatment increased TRPV1 protein expression in small and medium DRG neurons 14 days after treatment. Antibody double labeling revealed that isolectin B4-positive small DRG neurons co-expressed TRPV1. TRPV1 immunostaining was up-regulated in paw skin day 14 after paclitaxel treatment. Moreover, in situ hybridization histochemistry revealed that most of the TRPV1 mRNA-labeled neurons in the DRG were small or medium in size. These results suggest that paclitaxel treatment increases TRPV1 expression in DRG neurons and may contribute to functional peripheral neuropathic pain. PMID:23602343

Hara, Tomomi; Chiba, Terumasa; Abe, Kenji; Makabe, Akiko; Ikeno, Souichi; Kawakami, Kazuyoshi; Utsunomiya, Iku; Hama, Toshihiro; Taguchi, Kyoji

2013-06-01

268

Label-free detection of anticancer drug paclitaxel in living cells by confocal Raman microscopy  

NASA Astrophysics Data System (ADS)

Confocal Raman microscopy, a non-invasive, label-free, and high spatial resolution imaging technique is employed to trace the anticancer drug paclitaxel in living Michigan Cancer Foundation-7 (MCF-7) cells. The Raman images were treated by K-mean cluster analysis to detect the drug in cells. Distribution of paclitaxel in cells is verified by calculating the correlation coefficient between the reference spectrum of the drug and the whole Raman image spectra. A time dependent gradual diffusion of paclitaxel all over the cell is observed suggesting a complementary picture of the pharmaceutical action of this drug based on rapid binding of free tubulin to crystallized paclitaxel.

Salehi, H.; Derely, L.; Vegh, A.-G.; Durand, J.-C.; Gergely, C.; Larroque, C.; Fauroux, M.-A.; Cuisinier, F. J. G.

2013-03-01

269

Vasodilatation in the rat dorsal hindpaw induced by activation of sensory neurons is reduced by Paclitaxel  

PubMed Central

Peripheral neuropathy is a major side effect following treatment with the cancer chemotherapeutic drug paclitaxel. Whether paclitaxel-induced peripheral neuropathy is secondary to altered function of small diameter sensory neurons remains controversial. To ascertain whether the function of the small diameter sensory neurons was altered following systemic administration of paclitaxel, we injected male Sprague Dawley rats with 1 mg/kg paclitaxel every other day for a total of four doses and examined vasodilatation in the hindpaw at day 14 as an indirect measure of calcitonin gene related peptide (CGRP) release. In paclitaxel-treated rats, the vasodilatation induced by either intradermal injection of capsaicin into the hindpaw or electrical stimulation of the sciatic nerve was significantly attenuated in comparison to vehicle-injected animals. Paclitaxel treatment, however, did not affect direct vasodilatation induced by intradermal injection of methacholine or CGRP, demonstrating that the blood vessels’ ability to dilate was intact. Paclitaxel treatment did not alter the compound action potentials or conduction velocity of C-fibers. The stimulated release of CGRP from the central terminals in the spinal cord was not altered in paclitaxel-injected animals. These results suggest that paclitaxel affects the peripheral endings of sensory neurons to alter transmitter release, and this may contribute to the symptoms seen in neuropathy.

Gracias, N.G.; Cummins, T.R.; Kelley, M.R.; Basile, D.P.; Iqbal, T.; Vasko, M.R.

2010-01-01

270

Overcoming paclitaxel resistance in uterine endometrial cancer using a COX-2 inhibitor.  

PubMed

Cyclooxygenase (COX)-2 inhibitors have been reported to potentially modulate the resistance of cancer cells to chemotherapeutic drugs by affecting multidrug resistance 1 (MDR1) expression. In the present study, we investigated the association between COX-2 and MDR1 expression in endometrial cancers and evaluated the effects of the COX-2 inhibitor, etodolac, in combination with paclitaxel on paclitaxel-resistant endometrial cancer cells. The relationship between COX-2 and MDR1 mRNA expression was examined by quantitative PCR in 36 endometrial cancer specimens. The paclitaxel-resistant cell line OMC-2P was established from OMC-2 cells. Paclitaxel (1 µg/ml) with or without etodolac (10 µg/ml) was added to OMC-2 and OMC-2P cells, and COX-2 and MDR1 mRNA expression levels were examined. The concentration of prostaglandin E2 (PGE2) in the supernatant of each cell line was examined by enzyme-linked immunosorbent assay. The function of MDR1 was determined by intracellular accumulation of rhodamine 123 using flow cytometry, and the concentration of intracellular paclitaxel was determined by high-performance liquid chromatography. We found a positive relationship between COX-2 and MDR1 mRNA expression in endometrial cancer. Both COX-2 mRNA expression and PGE2 production were elevated in resistant OMC-2P cells when compared to non-resistant OMC-2 cells. Additionally, MDR1 mRNA expression was markedly upregulated in OMC-2P cells. In OMC-2 cells, COX-2 and MDR1 mRNA levels were significantly upregulated by paclitaxel treatment and downregulated by co-administration with etodolac. In OMC-2P cells, COX-2 mRNA expression was also significantly upregulated by paclitaxel treatment and tended to be downregulated by co-administration with etodolac. Moreover, co-administration of paclitaxel and etodolac suppressed the induction of MDR1 mRNA. Rhodamine 123 efflux was increased in OMC-2P cells when compared to the efflux in the OMC-2 cells and was increased in response to paclitaxel treatment. Co-administration of paclitaxel and etodolac in both cell lines resulted in decreased rhodamine 123 efflux. The actual concentration of intracellular paclitaxel in OMC-2P cells was significantly lower than that in OMC-2 cells treated with paclitaxel alone and was significantly increased after co-administration of paclitaxel and etodolac. These findings suggest that paclitaxel resistance may be associated with COX-2 and MDR1 expression in cancer cells. Co-administration of COX-2 inhibitors and paclitaxel may have a key role in modulating or overcoming paclitaxel resistance in endometrial cancers. PMID:24100466

Hasegawa, Kiyoshi; Ishikawa, Kunimi; Kawai, Satoshi; Torii, Yutaka; Kawamura, Kyoko; Kato, Rina; Tsukada, Kazuhiko; Udagawa, Yasuhiro

2013-12-01

271

Neuroprotection of paclitaxel against cerebral ischemia/reperfusion-induced brain injury through JNK3 signaling pathway.  

PubMed

In this study, we investigated the neuroprotective effects of paclitaxel in transient cerebral ischemia and possible regulatory mechanism of these neuroprotection. Our data showed that paclitaxel can down-regulate the increased MLK3, JNK3, c-Jun, Bcl-2, and caspase-3 phosphorylation induced by ischemia injury. Cresyl violet staining and immunohistochemistry results demonstrated that paclitaxel had neuroprotective effect against ischemia/reperfusion-induced neuronal cell death. These results indicated that paclitaxel has neuroprotection in ischemic injury through JNK3 signaling pathway and provided a novel possible drug in therapeutics of brain ischemia. PMID:22060185

Qi, Su-Hua; Zhao, Hui; Gong, Juan-Juan; Sun, Fu-Mou; Yue, Jun; Guan, Qiu-Hua; Wang, Min

2011-12-01

272

Pemirolast potently attenuates paclitaxel hypersensitivity reactions through inhibition of the release of sensory neuropeptides in rats.  

PubMed

The effects of anti-allergic agents on the hypersensitivity reactions to paclitaxel, an anti-cancer agent, were examined in rats. Intravenous injection of paclitaxel (15 mg/kg) caused a marked extravasation of plasma protein in lungs and a transient decrease in arterial partial oxygen pressure (PaO(2)). The paclitaxel-induced protein extravasation was inhibited by low doses (0.1-1 mg/kg) of pemirolast or high doses (30-100 mg/kg) of cromoglycate. However, ketotifen was not effective. The decrease in PaO(2) induced by paclitaxel was also significantly reversed by pemirolast. On the other hand, the paclitaxel-induced plasma extravasation was not attenuated by a histamine H(1) blocker diphenhydramine or an H(2) blocker famotidine, but was significantly reduced by a neurokinin NK(1) antagonist LY303870 (0.5 mg/kg) and an NK(2) antagonist SR48968 (1 mg/kg). The concentrations of proteins and sensory peptides such as substance P, neurokinin A and calcitonin gene-related peptide but not histamine in the rat bronchoalveolar lavage fluid were elevated by paclitaxel injection. Both cromoglycate and pemirolast reduced the paclitaxel-induced rise in proteins and sensory peptides. Therefore, we demonstrated for the first time that sensory nerve peptides are involved in paclitaxel hypersensitivity and that an anti-allergic agent pemirolast attenuates the paclitaxel response by inhibiting the release of sensory nerve peptides. PMID:15033348

Itoh, Yoshinori; Sendo, Toshiaki; Hirakawa, Toshio; Takasaki, Shinya; Goromaru, Takeshi; Nakano, Hitoo; Oishi, Ryozo

2004-05-01

273

A TPGS-incorporating nanoemulsion of paclitaxel circumvents drug resistance in breast cancer.  

PubMed

Paclitaxel resistance is usually developed in clinical chemotherapy, which remains a major obstacle for successful cancer treatment. Herein, we attempted to develop a TPGS incorporating nanoemulsion of paclitaxel (NE-PTX) to circumvent the drug resistance in breast cancer. NE-PTX was prepared by a self-assembly technique and the physicochemical properties were characterized. The efficacy of NE-PTX on overcoming paclitaxel resistance was measured by in vitro and in vivo evaluation. The measured results indicated that NE-PTX was nanometer-sized droplets with the mean diameter of 24.93±3.45nm. The IC50 value of paclitaxel in resistant MCF-7/ADR cells was greatly reduced from 101.45?g/mL to 5.39?g/mL, which indicated that the paclitaxel resistance was effectively reduced by NE-PTX. The reversal of paclitaxel resistance could mainly ascribe to the significant inhibition of P-gp activity and enhancement of anti-cancer activity. Moreover, the tumor volume in resistant tumor xenograft model treated with NE-PTX was only 10.06% of that of paclitaxel solution group, and the tumor inhibitory rate of NE-PTX reached 93.84%, which effectively verified the efficacy of NE-PTX on treating paclitaxel resistance. Thereby, NE-PTX could provide an effective strategy for circumventing paclitaxel resistance in breast cancer. PMID:24866272

Bu, Huihui; He, Xinyu; Zhang, Zhiwen; Yin, Qi; Yu, Haijun; Li, Yaping

2014-08-25

274

Archaeosome: as new drug carrier for delivery of Paclitaxel to breast cancer.  

PubMed

In the present study, paclitaxel was archaeosomed to reduce side effects and improve its therapeutic index. Carriers have made a big evolution in treatment of many diseases in recent years. Lipid carriers are of special importance among carriers. Archaeosome is one of the lipid carriers. Paclitaxel is one of the drugs used to treat breast cancer which has some unwanted side effects despite its therapeutic effects. Archaeosomes were extracted from methanogenic archi bacteria and synthesized with a certain ratio of paclitaxel in PBS. The mean diameter of archaeosomal paclitaxel was measured by Zeta sizer instrument, Drug releasing of archaeosomal paclitaxel was examined within 26 h which results showed that the most drug releasing occurs during first 3 h. The cytotoxicity effect of archaeosomal paclitaxel on breast cancer's cell line was evaluated by MTT assay which results showed that the cytotoxicity effect of archaeosomal paclitaxel on breast cancer's cell line is more than that of the standard paclitaxel formulation. The results indicated that new drug delivery of paclitaxel using archaeosome, increases the therapeutic index of the drug. PMID:24757295

Alavi, Seyed Ebrahim; Mansouri, Hamidreza; Esfahani, Maedeh Koohi Moftakhari; Movahedi, Fatemeh; Akbarzadeh, Azim; Chiani, Mohsen

2014-04-01

275

A synergistic combination therapy with paclitaxel and doxorubicin loaded micellar nanoparticles.  

PubMed

Doxorubicin was chemically conjugated to a biodegradable polymeric carrier as a polymer-doxorubicin (polymer-Dox) conjugate via an acid labile Schiff-base bond. Then, paclitaxel was physically encapsulated by the polymer-Dox conjugate to self assemble in water as micellar nanoparticles with both doxorubicin and paclitaxel in one nanoparticle. In this way, doxorubicin and paclitaxel were combined. The preparation of the polymer-doxorubicin conjugates, encapsulation of paclitaxel, characterization of nanoparticles was systematically studied and the biological evaluation of the free drug combination as well as the micellar platform combination in vitro was thoroughly detailed. PMID:24441457

Wang, Yan; Ma, Shurong; Xie, Zhongshi; Zhang, Haishan

2014-04-01

276

Studies on paclitaxel-loaded glyceryl monostearate nanoparticles.  

PubMed

Solid lipid nanoparticles (SLNs) of Paclitaxel were prepared by modified Hot homogenization method using Glyceryl monostearate (GMS). The SLNs were characterized for its physicochemical characteristics such as mean particle size, percentage entrapment efficiency and zeta potential, which were found to be 226 nm, 92.43% and -29.4 mV, respectively. The Transmission Electron Microscopy (TEM) studies showed that prepared SLNs were of spherical shape. The drug retarding efficiency of the lipid (GMS) was better in pH 7.4 compared to pH 3.5. The release profile showed a tendency to follow Higuchi diffusion pattern at pH 7.4 and Peppas-Korsenmeyer model at pH 3.5. Chemosensitivity assay carried out using B16F10 cell lines showed that anti-proliferative activity of Paclitaxel was not hindered due to encapsulation. PMID:19169921

Shenoy, Vikram Subraya; Rajyaguru, Tushar Himmatlal; Gude, Rajiv Phondu; Murthy, Rayasa S Ramchandra

2009-09-01

277

Thermosensitive and biodegradable polymeric micelles for paclitaxel delivery  

Microsoft Academic Search

The preparation, release and in vitro cytotoxicity of a novel polymeric micellar formulation of paclitaxel (PTX) were investigated. The micelles consisted of an AB block copolymer of poly(N-(2-hydroxypropyl) methacrylamide lactate) and poly(ethylene glycol) (pHPMAmDL-b-PEG). Taking advantage of the thermosensitivity of pHPMAmDL-b-PEG, the loading was done by simply mixing of a small volume of a concentrated PTX solution in ethanol and

Osamu Soga; Cornelus F. van Nostrum; Marcel Fens; Cristianne J. F. Rijcken; Raymond M. Schiffelers; Gert Storm; Wim E. Hennink

2005-01-01

278

Paclitaxel-coated balloons - Survey of preclinical data.  

PubMed

Restenosis following interventions in the coronary or peripheral arteries develops over weeks to months. In coronary arteries the restenosis rate has been markedly reduced since the advent of drug-eluting stents. Non-stent-based methods for local drug delivery enable restenosis inhibition without the need for stent implantation, does not permanently change the structure of the vessel, are repeatable, and seems to be applicable where drug-eluting stents provide insufficient protection. Preclinical data indicate that short exposure of the vessel wall to a lipophilic inhibitor of cell proliferation is sufficient for preventing restenosis. Initial evidence to this effect emerged from an investigation of paclitaxel embedded in a matrix that enhances the solubility and release of the agent from the balloon coating as well as its transfer to the vessel wall. Further corroborating data from preclinical and clinical studies demonstrating a reduction in late lumen loss and lower restenosis rates led to the market introduction of a variety of paclitaxel-coated angioplasty balloons. The effectiveness of restenosis inhibition is not determined by the active agent alone. Other factors that are crucial for the effectiveness and safety of drug-coated angioplasty balloons are the formulation containing the agent and the coating technique. In this review we first outline the development of paclitaxel-coated balloons to then provide an overview of the preclinical results obtained with different paclitaxel-coated balloons and finally compare these with the outcome in patients. The article concludes with a short outlook on initial results with a zotarolimus-coated angioplasty balloon. PMID:20948503

Schnorr, B; Kelsch, B; Cremers, B; Clever, Y P; Speck, U; Scheller, B

2010-10-01

279

Cardioprotection by dexrazoxane in rats treated with doxorubicin and paclitaxel  

Microsoft Academic Search

Purpose: Results of several clinical studies suggest that the combination of doxorubicin (DOX) and paclitaxel (PTX) is highly active\\u000a against solid tumors. Both drugs are known to cause adverse cardiac effects, cardiomyopathy in the case of DOX and acute changes\\u000a in cardiac rhythm in the case of PTX. It has been suggested that the addition of dexrazoxane (DZR) to this

Paola Della Torre; Anthony R. Imondi; Claudio Bernardi; Arturo Podestà; Donatella Moneta; Mariagrazia Riflettuto; Guy Mazué

1999-01-01

280

Potential of Negatively Charged Pectin Nanoparticles Encapsulating Paclitaxel: Preparation & Characterization  

Microsoft Academic Search

Sugars with their three dimensional structures are important for many biological functions. We report preparation of negatively charged pectin nanoparticles and its efficacy as a drug delivery vehicle for anticancer drug Paclitaxel assessed. Pectin nanoparticles were prepared by ionic gelation having a mean diameter of ~300350nm, and were stable over a wide range of temperature and pH. FT-IR spectra revealed

Anita K. Verma; A. Chanchal; A. Kumar

2011-01-01

281

Carrier proteins determine local pharmacokinetics and arterial distribution of paclitaxel.  

PubMed

The growing use of local drug delivery to vascular tissues has increased interest in hydrophobic compounds. The binding of these drugs to serum proteins raises their levels in solution, but hinders their distribution through tissues. Inside the arterial interstitium, viscous and steric forces and binding interactions impede drug motion. As such, this might be the ideal scenario for increasing the amount of drug delivered to, and residence time within, arterial tissues. We quantified carrier-mediated transport for paclitaxel, a model hydrophobic agent with potential use in proliferative vascular diseases, by determining, in the presence or absence of carrier proteins, the maximum concentration of drug in aqueous solution, the diffusivity in free solution, and the diffusivity in arterial tissues. Whereas solubility of paclitaxel was raised 8.1-, 21-, and 57-fold by physiologic levels of alpha(1)-acid glycoproteins, bovine serum albumin, and calf serum over that in protein-free solution, diffusivity of paclitaxel in free solution was reduced by 41, 49, and 74%, respectively. When paclitaxel mixed in these solutions was applied to arteries both in vitro and in vivo, drug was more abundant at the tissue interface, but protein carriers tended to retain drug in the lumen. Once within the tissue, these proteins did not affect the rate at which drug traverses the tissue because this hydrophobic drug interacted with the abundant fixed proteins and binding sites. The protein binding properties of hydrophobic compounds allow for beneficial effects on transvascular transport, deposition, and distribution, and may enable prolonged effect and rationally guide local and systemic strategies for their administration. PMID:11745785

Lovich, M A; Creel, C; Hong, K; Hwang, C W; Edelman, E R

2001-09-01

282

Extravasation of paclitaxel into breast tissue from central catheter port  

Microsoft Academic Search

A 53-year-old woman with advanced-stage ovarian cancer experienced extravasation of paclitaxel into the breast tissue as a result of inappropriate needle insertion and\\/or dislodgement; it came from a central catheter port (CCP) that was found to be intact under radiological examination with contrast material. The breast became tender and oedematous with erythema, and local warming was observed within a few

Sabri Barutca; Gurhan Kadikoylu; Zahit Bolaman; Nezih Meydan; Irfan Yavasoglu

2002-01-01

283

Targeting of albumin-embedded paclitaxel nanoparticles to tumors  

Microsoft Academic Search

We have used tumor-homing peptides to target abraxane, a clinically approved paclitaxel-albumin nanoparticle, to tumors in mice. The targeting was accomplished with two peptides, CREKA and LyP-1 (CGNKRTRGC). Fluorescein (FAM)-labeled CREKA-abraxane, when injected intravenously into mice bearing MDA-MB-435 human cancer xenografts, accumulated in tumor blood vessels, forming aggregates that contained red blood cells and fibrin. FAM-LyP-1-abraxane co-localized with extravascular islands

Priya Prakash Karmali; Venkata Ramana Kotamraju; Mark Kastantin; Matthew Black; Dimitris Missirlis; Matthew Tirrell; Erkki Ruoslahti

2009-01-01

284

Serine protease inhibitor TPCK prevents Taxol-induced cell death and blocks cRaf1 and Bcl2 phosphorylation in human breast carcinoma cells  

Microsoft Academic Search

The mechanism of Taxol-induced apoptosis was investigated in MCF-7 human breast carcinoma cells. Taxol-induced apoptosis was associated with phosphorylation of both c-Raf-1 and Bcl-2 and activation of ERK and JNK MAP kinases. The serine protease inhibitor N-tosyl-L-phenylalanine chloromethyl ketone (TPCK) effectively blocked apoptosis, but N-p-tosyl-L-lysine chloromethyl ketone (TLCK), another serine protease inhibitor, was without effect. TPCK treatment also prevented phosphorylation

Ying Huang; M Saeed Sheikh; Albert J Fornace; Nikki J Holbrook

1999-01-01

285

A fungal taxol from Botryodiplodia theobromae Pat., attenuates 7, 12 dimethyl benz(a)anthracene (DMBA)-induced biochemical changes during mammary gland carcinogenesis  

Microsoft Academic Search

The aim of this study was to investigate the anticancer activity of fungal taxol against dimethyl benz(a)anthracene (DMBA)-induced mammary gland carcinogenesis in Sprague Dawley rats. After 90 days of tumor induction, fungal and commercial taxol were administered intraperitoneally once a week for four weeks. Tissues were analyzed for biochemical markers that included aspartate aminotransaminase (AST), alanine aminotransaminase (ALT), acid phosphatase

M. Pandi; P. Rajapriya; G. Suresh; N. Ravichandran; R. Manikandan; R. Thiagarajan; J. Muthumary

2011-01-01

286

Taxol induces caspase-independent cytoplasmic vacuolization and cell death through endoplasmic reticulum (ER) swelling in ASTC-a-1 cells  

Microsoft Academic Search

High concentration of taxol was found to induce programmed cell death (PCD) and cytoplasm vacuolization in human lung adenocarcinoma (ASTC-a-1) cells. To elucidate the relationship between the PCD and cytoplasm vacuolization, confocal fluorescence microscopy was performed on the cytoplasm vacuolization, endoplasmic reticulum (ER) and mitochondria swelling after taxol treatment in living cells. erRFP plasmid was used to probe the ER

Tong-sheng Chen; Xiao-ping Wang; Lei Sun; Long-xiang Wang; Da Xing; Martin Mok

2008-01-01

287

In vitro activity of taxol and taxotere in comparison with doxorubicin and cisplatin on primary cell cultures of human breast cancers  

Microsoft Academic Search

Thein vitro activities of taxol and taxotere in comparison with cisplatin and doxorubicin were assessed in 30 primary tumor cultures from human breast cancers. Both taxanes were much more potent than cisplatin and doxorubicin. Taxotere was 3.1; 296, and 9.6-fold more cytotoxic than taxol, cisplatin, and doxorubicin respectively. The cytotoxic activity observed in our experiments confirms the potential clinical relevance

Wainer Zoli; Alberto Flamigni; Giovanni Luca Frassineti; Paola Bajorko; Franca De Paola; Carlo Milandri; Dino Amadori; Anna Gasperi-Campani

1995-01-01

288

Sgk1 enhances RANBP1 transcript levels and decreases taxol sensitivity in RKO colon carcinoma cells.  

PubMed

The serum- and glucocorticoid-regulated kinase (Sgk1) is essential for hormonal regulation of epithelial sodium channel-mediated sodium transport and is involved in the transduction of growth factor-dependent cell survival and proliferation signals. Growing evidence now points to Sgk1 as a key element in the development and/or progression of human cancer. To gain insight into the mechanisms through which Sgk1 regulates cell proliferation, we adopted a proteomic approach to identify up- or downregulated proteins after Sgk1-specific RNA silencing. Among several proteins, the abundance of which was found to be up- or downregulated upon Sgk1 silencing, we focused our attention of RAN-binding protein 1 (RANBP1), a major effector of the GTPase RAN. We report that Sgk1-dependent regulation of RANBP1 has functional consequences on both mitotic microtubule activity and taxol sensitivity of cancer cells. PMID:23108393

Amato, R; Scumaci, D; D'Antona, L; Iuliano, R; Menniti, M; Di Sanzo, M; Faniello, M C; Colao, E; Malatesta, P; Zingone, A; Agosti, V; Costanzo, F S; Mileo, A M; Paggi, M G; Lang, F; Cuda, G; Lavia, P; Perrotti, N

2013-09-19

289

[Weekly paclitaxel therapy is curative for patients with retroperitoneal liposarcoma].  

PubMed

In March 2004, we resected a giant retroperitoneal liposarcoma and the transverse colon, spleen and left kidney in a 58-year-old woman. In July, recurrence was detected in the right pelvis and left upper abdomen; therefore, we resected the tumor. In September 2004, computed tomography (CT) revealed multiple recurrences in the right lower abdomen, left upper abdomen, front of the left lobe of the liver, and at the back of the stomach. In October 2004, we started mesna, doxorubicin, ifosfamide, and dacarbazine therapy (MAID); however, after 1 course, the disease progressed, and the patient developed edema in the bilateral legs due to inferior vena cava (IVC) compression. In November 2004, we started weekly paclitaxel therapy (100 mg/m(2), once a week for 3 weeks followed by 1 drug-free week). CT revealed no change as a result of chemotherapy; however, IVC compression had improved, and leg edema had decreased. In August 2005, chemotherapy was stopped; therefore,the patient's condition worsened. She died in September 2005. We performed weekly paclitaxel therapy for the patient with recurrent liposarcoma. This improved her symptoms and quality of life (QOL). Therefore,we consider weekly paclitaxel therapy to be effective for liposarcoma treatment. PMID:17353645

Yoshida, Yasushi; Inoue, Katsuhiko; Ohsako, Tomofumi; Nagamoto, Nobuhide; Tanaka, Eiji; Tsuruzoe, Shu

2007-03-01

290

Phase I study of temozolomide plus paclitaxel in patients with advanced malignant melanoma and associated in vitro investigations  

Microsoft Academic Search

The purpose of this study was to determine activity of temozolomide combined with paclitaxel or epothilone B in vitro, and to investigate the combination of temozolomide with paclitaxel in a Phase I clinical trial. Melanoma cell lines A375P and DX3 were treated with temozolomide and either paclitaxel or epothilone B. Combination indices were determined to assess the degree of synergism.

A Azzabi; A N Hughes; P M Calvert; E R Plummer; R Todd; M J Griffin; M J Lind; A Maraveyas; C Kelly; K Fishwick; A H Calvert; A V Boddy

2005-01-01

291

Mechanisms of Paclitaxel-Induced Apoptosis in an Ovarian Cancer Cell Line and Its Paclitaxel-Resistant Clone  

Microsoft Academic Search

Background: To understand the complicated network of paclitaxel (PTX)-induced apoptosis pathways and to elucidate mechanisms of drug resistance in ovarian cancer, we looked at PTX-induced apoptosis by using cDNA microarray. We also quantitated the changes in apoptosis-related proteins in the process of apoptosis. Methods: An ovarian cancer cell line KF, and its PTX-resistant clone KFTX, were treated with PTX or

Masaki Sugimura; Satoru Sagae; Shin-ichi Ishioka; Yoshihiro Nishioka; Kuniko Tsukada; Ryuichi Kudo

2004-01-01

292

nab-Paclitaxel in combination with biologically targeted agents for early and metastatic breast cancer.  

PubMed

Taxanes are highly active chemotherapeutic agents used in the treatment of early-stage and metastatic breast cancer. Novel formulations have been developed to improve efficacy and decrease toxicity associated with these cytotoxic agents. nab-Paclitaxel is a biologically interactive, solvent-free, 130-nm-sized albumin-bound paclitaxel, developed to avoid the Cremophor vehicle used in solvent-based paclitaxel. Based on a pivotal phase 3 study, nab-paclitaxel was shown to be safely infused at a significantly higher dose of paclitaxel than the doses used with standard paclitaxel therapy, and had a shorter infusion time, no premedication, and higher response rates. It is now approved in the United States for treatment of breast cancer after failure of combination chemotherapy for metastatic disease or relapse within 6 months of adjuvant therapy, and has demonstrated promising efficacy and favorable tolerability. Recently, several phase 2 and 3 studies have suggested a role for nab-paclitaxel in combination with biologically targeted agents for the treatment of early- and late-stage breast cancer. This review will discuss the findings of clinical trials evaluating nab-paclitaxel in combination with biologically targeted therapeutic agents for breast cancer in the neoadjuvant, adjuvant, and metastatic settings. PMID:24560997

Megerdichian, Christine; Olimpiadi, Yuliya; Hurvitz, Sara A

2014-06-01

293

Paclitaxel: Ein Chemotherapeutikum zur Restenoseprophylaxe? Experimentelle Untersuchungen in vitro und in vivo  

Microsoft Academic Search

Summary Paclitaxel, a potent anti-tumor agent, shifts the cytoskeleton equilibrium towards assembly of altered and extraordinarily stable microtubules. These cellular modifications lead to reduced proliferation, migration, and signal transduction. It is highly lipophilic, which promotes a rapid cellular uptake, and has a long-lasting effect in the cell due to the structural alteration of the cytoskeleton. This makes paclitaxel a promising

C. Herdeg; M. Oberhoff; D. I. Siegel-Axel; A. Baumbach; A. Blattner; A. Küttner; S. Schröder; K. R. Karsch

2000-01-01

294

Chemoprophylaxis with Ciprofloxacin in Ovarian Cancer Patients Receiving Paclitaxel: A Randomized Trial  

Microsoft Academic Search

The objective of this study was to evaluate the efficacy of oral ciprofloxacin in preventing febrile morbidity superimposed on the neutropenia induced from a paclitaxel regimen in ovarian cancer patients. Eligible patients received paclitaxel at doses of 135 to 175 mg\\/m2alone or in combination with a platinum agent. They were randomized to either an observation (control) group or a ciprofloxacin

J. W. Carlson; J. M. Fowler; S. K. Mitchell; L. F. Carson; A. R. Mayer; L. J. Copeland

1997-01-01

295

Low-Dose Oxaliplatin Enhances the Antitumor Efficacy of Paclitaxel in Human Gastric Cancer Cell Lines  

Microsoft Academic Search

Background: The enhanced antitumor effect of paclitaxel when used with oxaliplatin in gastric cancer is reported, however the underlying biological mechanism is unknown. Methods: We tested the cytotoxic activity, apoptosis, and mitotic catastrophe of paclitaxel and oxaliplatin in MKN-28 and MKN-45 gastric cancer cell lines. The modulation of survivin expression was determined by Western blotting. Results: WST-1 assay indicated that

Jinyu Gu; Hirofumi Yamamoto; Xueying Lu; Chew Yee Ngan; Tadashi Tsujino; Ken Konishi; Ichiro Takemasa; Masataka Ikeda; Hiroshi Nagata; Shusuke Hashimoto; Takeshi Matsuzaki; Mitsugu Sekimoto; Akimitsu Takagi; Morito Monden

2006-01-01

296

Preparation and biological activity of a paclitaxel-single-walled carbon nanotube complex.  

PubMed

Single-walled carbon nanotubes (SWCNTs) have unique transmembrane abilities. The huge superficial area and abundance of ? electrons confer SWCNTs perfect absorptive capability toward proteins, nucleates, and many drugs. These characteristics make SWCNTs a new and efficient drug carrier. The purpose of this study was to disperse SWCNTs in water and have paclitaxel absorbed onto them in order to construct an asparagine-glycine-arginine (NGR)-SWCNT-Paclitaxel complex as a targeting nanoparticle system. The NGR-SWCNT-Paclitaxel complex was systematically studied, and analytical methods, including spectrophotometry for SWCNTs and high-performance liquid chromatography for paclitaxel, were employed. The preparation and the prescription of the NGR-SWCNT-Paclitaxel complex lyophilized powder were investigated. MCF-7 cancer cells, Sprague-Dawley rats, and S180 tumor-bearing mice were used as experimental subjects to evaluate the in vitro and in vivo activity of NGR-SWCNT-Paclitaxel complex dispersion. The complex dispersion showed obvious inhibition activity against MCF-7 cancer cells. Within 1 h, the NGR-SWCNT-Paclitaxel complex could be transferred to cells, and sustained the release of drugs. In addition, the tumor and liver targeting and improved therapeutic effects of the NGR-SWCNT-Paclitaxel complex were confirmed. PMID:24668633

Fu, X D; Zhang, Y Y; Wang, X J; Shou, J X; Zhang, Z Z; Song, L J

2014-01-01

297

First line treatment of advanced non-small-cell lung cancer - specific focus on albumin bound paclitaxel  

PubMed Central

Lung cancer is the leading cause of cancer mortality worldwide in both men and women. Non-small-cell lung cancer (NSCLC) is the most common type of lung cancer, accounting for more than 80% of cases. Paclitaxel has a broad spectrum of activity against various malignancies, including NSCLC. Paclitaxel is poorly soluble in water and thus, until recently, its commercially available preparations contained a non-ionic solvent Cremophor EL®. Cremophor EL® improves the solubility of paclitaxel and allows its intravenous administration. However, certain side-effects associated with paclitaxel, such as hypersensitivity reactions, myelosuppression, and peripheral neuropathy, are known to be worsened by Cremophor®. Nanoparticle albumin-bound paclitaxel ([nab-paclitaxel] ABRAXANE® ABI-007) is a new generation formulation of paclitaxel that obviates the need for Cremophor®, resulting in a safer and faster infusion without requiring the use of premedications to avoid hypersensitivity. Albumin-binding receptor-mediated delivery and lack of sequestering Cremophor® micelles allow higher intratumoral concentration of pharmacologically active paclitaxel. Multiple clinical trials have demonstrated a superior tolerability profile of nab-paclitaxel in comparison to solvent-bound paclitaxel (sb-paclitaxel). A recent Phase III trial compared the effects of weekly nab-paclitaxel in combination with carboplatin versus sb-paclitaxel in combination with carboplatin given every 3 weeks for first line treatment of NSCLC. This trial highlights the weekly nab-paclitaxel combination as an alternate treatment option for NSCLC, with higher response rate in squamous cell NSCLC and longer survival in elderly patients. This review will focus on the properties of nab-paclitaxel and its use in the first line treatment of NSCLC.

Gupta, Neha; Hatoum, Hassan; Dy, Grace K

2014-01-01

298

Induction of Paclitaxel Resistance by the Kaposi's Sarcoma-Associated Herpesvirus Latent Protein LANA2?  

PubMed Central

Kaposi's sarcoma-associated herpesvirus (KSHV) is the causal agent of both KS and primary effusion lymphoma (PEL). Although treatment with paclitaxel has significant antitumor activity in KS, drug resistance represents a major obstacle for improving the overall response and survival of PEL patients. The transcriptional pattern of KSHV is cell/tissue specific, as revealed by the fact that the viral latent protein LANA2 is detected exclusively in B cells. This paper focuses on the mechanism of paclitaxel resistance observed in PEL cells. Here we show that LANA2 protein modulates microtubule dynamics through its direct binding to polymerized microtubules, preventing microtubule stabilization induced by paclitaxel. This is the first demonstration of paclitaxel resistance induced by a viral protein and suggests a link between the expression of LANA2 and the resistance of PEL cells to paclitaxel.

Munoz-Fontela, C.; Marcos-Villar, L.; Hernandez, F.; Gallego, P.; Rodriguez, E.; Arroyo, J.; Gao, S.-J.; Avila, J.; Rivas, C.

2008-01-01

299

Acetyl-L-carnitine prevents and reduces paclitaxel-induced painful peripheral neuropathy.  

PubMed

This study examines the potential efficacy of acetyl-L-carnitine (ALC) to prevent and treat paclitaxel-induced pain. Rats received four intraperitoneal (i.p.) injections of 2 mg/kg paclitaxel on alternate days which, following a short delay induced marked mechanical hypersensitivity. Daily administration of ALC (50 mg/kg and 100 mg/kg; p.o.; concurrently with paclitaxel and for 14 days afterwards) prevented the development of paclitaxel-induced pain. This effect was long lasting, for at least 3 weeks after the last dose of ALC. In a separate experiment, daily administration of ALC (100 mg/kg; p.o.; for 10 days) to rats with established paclitaxel-induced pain produced an analgesic effect. This effect dissipated shortly after ALC treatment was withdrawn. We conclude that ALC may be useful in the prevention and treatment of chemotherapy-induced painful peripheral neuropathy. PMID:16406309

Flatters, Sarah J L; Xiao, Wen-Hua; Bennett, Gary J

2006-04-24

300

The Extracellular Matrix Protein TGFBI Induces Microtubule Stabilization and Sensitizes Ovarian Cancers to Paclitaxel  

PubMed Central

Summary The extracellular matrix (ECM) can induce chemotherapy resistance via AKT-mediated inhibition of apoptosis. Here, we show that loss of the ECM protein TGFBI (transforming growth factor beta induced) is sufficient to induce specific resistance to paclitaxel and mitotic spindle abnormalities in ovarian cancer cells. Paclitaxel-resistant cells treated with recombinant TGFBI protein show integrin-dependent restoration of paclitaxel sensitivity via FAK- and Rho-dependent stabilization of microtubules. Immunohistochemical staining for TGFBI in paclitaxel-treated ovarian cancers from a prospective clinical trial showed that morphological changes of paclitaxel-induced cytotoxicity were restricted to areas of strong expression of TGFBI. These data show that ECM can mediate taxane sensitivity by modulating microtubule stability.

Ahmed, Ahmed Ashour; Mills, Anthony D.; Ibrahim, Ashraf E.K.; Temple, Jillian; Blenkiron, Cherie; Vias, Maria; Massie, Charlie E.; Iyer, N. Gopalakrishna; McGeoch, Adam; Crawford, Robin; Nicke, Barbara; Downward, Julian; Swanton, Charles; Bell, Stephen D.; Earl, Helena M.; Laskey, Ronald A.; Caldas, Carlos; Brenton, James D.

2007-01-01

301

Successful treatment by adding duloxetine to pregabalin for peripheral neuropathy induced by paclitaxel.  

PubMed

Although paclitaxel is a commonly used anticancer drug, peripheral neuropathy may develop as a side effect. Worsening of the symptoms with time may cause patients who receive paclitaxel to give up their chemotherapy. Duloxetine, a serotonin- and norepinephrine-reuptake inhibitor, has been used to treat peripheral neuropathic pain. We report the case of a 68-year-old man with gastric cancer, who underwent gastrectomy and then received 8 cycles of chemotherapy involving weekly administrations of paclitaxel. Under this paclitaxel treatment, he complained of severe peripheral neuropathy, leading to a diminished quality of life. Following treatment with a combination of duloxetine and pregabalin, a remission of his symptoms was achieved. Duloxetine plus pregabalin therapy may be useful for the peripheral neuropathy induced by paclitaxel. PMID:23064035

Takenaka, Motoyasu; Iida, Hiroki; Matsumoto, Shigemi; Yamaguchi, Shinobu; Yoshimura, Noritaka; Miyamoto, Maki

2013-11-01

302

GS164, a small synthetic compound, stimulates tubulin polymerization by a similar mechanism to that of Taxol  

Microsoft Academic Search

Purpose: During our search for new microtubule effectors as anticancer agents, we have found that a small synthetic molecule designated\\u000a GS-164 interferes with the assembly of porcine microtubule proteins and has cytotoxic activity against a wide range of human\\u000a tumor cell lines. In this study, we investigated mode of action of the compound in comparison with Taxol and colcemid. Methods:

Yasushi Shintani; Toshimasa Tanaka; Yukimasa Nozaki

1997-01-01

303

Synergy of Taxol and rhein lysinate associated with the downregulation of ERK activation in lung carcinoma cells  

PubMed Central

In previous studies we observed that rhein lysinate (RHL), a salt of rhein and lysine that is easily dissolved in water, inhibited the growth of tumor cells in breast cancer, ovarian cancer, hepatocellular carcinoma and cervical cancer. The present study aimed to investigate the effects of RHL on H460 and A549 non-small cell lung cancer (NSCLC) cells using a combination of RHL and Taxol. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay was used to determine the growth inhibition effect of the drugs in the H460 and A549 cells. Cell apoptosis was analyzed by flow cytometry combined with fluorescein-isothiocyanate-Annexin V/propidium iodide (PI) staining. The expression levels of proteins were detected by western blotting. There was a significant reduction in the proliferation of the NSCLC cell lines treated with a combination of Taxol and RHL. The overall growth inhibition was directly correlated with apoptotic cell death. RHL potentiated Taxol-induced cell killing by reducing extracellular signal-regulated kinase (ERK) activity and increasing the levels of cleaved poly(ADP-ribose) polymerase (PARP) and caspase-3. Notably, the results for the Bcl-2 and NF-?B proteins also showed downregulation in the combined treatment group compared with the single-agent treatment and the untreated control groups. The present results showed that RHL potentiates the growth inhibition induced by Taxol in NSCLC cells and showed that this synergy may be associated with the downregulation of ERK activation.

ZHEN, YONG-ZHAN; HU, GANG; ZHAO, YU-FANG; YAN, FENG; LI, RAN; GAO, JUN-LING; LIN, YA-JUN

2013-01-01

304

Regulatory Polymorphisms in ?-Tubulin IIa Are Associated with Paclitaxel-Induced Peripheral Neuropathy  

PubMed Central

Purpose Peripheral neuropathy is the dose-limiting toxicity of paclitaxel, a chemotherapeutic drug widely used to treat several solid tumors such as breast, lung, and ovary. The cytotoxic effect of paclitaxel is mediated through ?-tubulin binding in the cellular microtubules. In this study, we investigated the association between paclitaxel neurotoxicity risk and regulatory genetic variants in ?-tubulin genes. Experimental Design We measured variation in gene expression of three ?-tubulin isotypes (I, IVb, and IIa) in lymphocytes from 100 healthy volunteers, sequenced the promoter region to identify polymorphisms putatively influencing gene expression and assessed the transcription rate of the identified variants using luciferase assays. To determine whether the identified regulatory polymorphisms were associated with paclitaxel neurotoxicity, we genotyped them in 214 patients treated with paclitaxel. In addition, paclitaxel-induced cytotoxicity in lymphoblastoid cell lines was compared with ?-tubulin expression as measured by Affymetrix exon array. Results We found a 63-fold variation in ?-tubulin IIa gene (TUBB2A) mRNA content and three polymorphisms located at ?101, ?112, and ?157 in TUBB2A promoter correlated with increased mRNA levels. The ?101 and ?112 variants, in total linkage disequilibrium, conferred TUBB2A increased transcription rate. Furthermore, these variants protected from paclitaxel-induced peripheral neuropathy [HR, 0.62; 95% confidence interval (CI), 0.42–0.93; P = 0.021, multivariable analysis]. In addition, an inverse correlation between TUBB2A and paclitaxel-induced apoptosis (P = 0.001) in lymphoblastoid cell lines further supported that higher TUBB2A gene expression conferred lower paclitaxel sensitivity. Conclusions This is the first study showing that paclitaxel neuropathy risk is influenced by polymorphisms regulating the expression of a ?-tubulin gene.

Leandro-Garcia, Luis J.; Leskela, Susanna; Jara, Carlos; Green, Henrik; Avall-Lundqvist, Elisabeth; Wheeler, Heather E.; Dolan, M. Eileen; Inglada-Perez, Lucia; Maliszewska, Agnieszka; de Cubas, Aguirre A.; Comino-Mendez, Inaki; Mancikova, Veronika; Cascon, Alberto; Robledo, Mercedes; Rodriguez-Antona, Cristina

2013-01-01

305

Gemcitabine plus paclitaxel versus carboplatin plus either gemcitabine or paclitaxel in advanced non-small-cell lung cancer: a literature-based meta-analysis.  

PubMed

The combination of gemcitabine plus paclitaxel has been proposed as an alternative to the platinum-based combinations for treatment of advanced non-small-cell lung cancer (NSCLC). However, conflicting results have been reported. This meta-analysis was performed to compare the activity, efficacy, and toxicity of gemcitabine plus paclitaxel versus carboplatin plus either gemcitabine or paclitaxel in patients with untreated advanced NSCLC. Randomized phase II and phase III clinical trials comparing gemcitabine plus paclitaxel with carboplatin plus gemcitabine or paclitaxel were collected from electronic databases (Medline, EMBASE, and the Cochrane Central Register of Controlled Trials), relevant reference lists, and abstract books. The published languages and years were not limited. Pooled odds ratios (ORs) were calculated for the 1-year survival rate (1-year SR), the overall response rate (ORR), and grade 3 and grade 4 toxicities. Four randomized controlled trials (2186 patients) were identified from 2051 reports. They were all published as full-text articles. No significant heterogeneity was detected in these studies. A significant difference in ORR favoring gemcitabine plus paclitaxel over carboplatin-based doublets was observed [OR = 1.20; 95% confidence interval (95% CI) = 1.02-1.42; P = 0.03], whereas the trend toward an improved 1-year SR was not significant (OR = 1.07; 95% CI = 0.91-1.26; P = 0.41). An increased risk of grade 3-4 toxicities for patients receiving carboplatin-based chemotherapy was statistically demonstrated. The gemcitabine plus paclitaxel combination showed an improved ORR and a better toxicity profile but a similar 1-year SR compared to carboplatin-based doublets. For nonplatinum-based chemotherapy, gemcitabine plus paclitaxel is a useful alternative. PMID:20703493

Li, Chenguang; Sun, Yihua; Pan, Yunjian; Wang, Qifeng; Yang, Shu; Chen, Haiquan

2010-10-01

306

An enzyme immunoassay for the determination of taxol and taxanes in Taxus sp. tissues and human plasma.  

PubMed

A rapid and sensitive indirect competitive inhibition enzyme immunoassay (CIEIA) method has been developed for quantitating taxanes in extracts of Taxus brevifolia Nutt. tissue and in human plasma. High titer rabbit polyclonal antibodies (pAb) were raised against a conjugate of 7-succinyltaxol and keyhole limpet hemocyanin. The presence of taxane analyte competitively inhibited the binding of the rabbit anti-taxane pAbs to a 7-succinyltaxol-bovine serum albumin solid phase coating antigen. The CIEIA detected taxol and cephalomannine in concentrations as low as 0.3 ng/ml (3.5 x 10(-4) microM), but did not detect baccatin III or 10-deacetylbaccatin III at concentrations below 1000 ng/ml (1.7 microM and 1.8 microM, respectively). This method is useful for estimating the taxane content of T. brevifolia extracts and may be useful for monitoring the taxol plasma level of taxol-treated patients. PMID:8094087

Grothaus, P G; Raybould, T J; Bignami, G S; Lazo, C B; Byrnes, J B

1993-01-14

307

Potentiation of paclitaxel activity by curcumin in human breast cancer cell by modulating apoptosis and inhibiting EGFR signaling.  

PubMed

It has been suggested that combined effect of natural products may improve the treatment effectiveness in combating proliferation of cancer cells. Here, we examined the combined anticancer activities of compounds of three natural origin including baicalein, curcumin, and resveratrol with chemotherapy drug paclitaxel respectively, which showed that combination of paclitaxel with curcumin exhibited synergistic growth inhibition and induced significant apoptosis in MCF-7 cell lines. Treatment of MCF-7 cell lines with paclitaxel and curcumin induced the apoptosis of regulatory protein Bcl-2 but decreased Bax expression. In addition, simultaneous treatment with paclitaxel and curcumin strongly inhibited paclitaxel-induced activities of EGFR signaling. Furthermore, the combination of paclitaxel and curcumin exerted increased anti-tumor efficacy on mouse models. Overall, our data described the promising therapeutic potential and underlying mechanisms of combining paclitaxel with curcumin in treating breast cancer. PMID:24318305

Zhan, Yingzhuan; Chen, Yinnan; Liu, Rui; Zhang, Han; Zhang, Yanmin

2014-08-01

308

Effects of paclitaxel and doxorubicin in histocultures of hepatocelular carcinomas.  

PubMed

Cancer has been the leading cause of death in Taiwan over the past two decades and liver cancer is the leading cause of all cancer deaths in Taiwan with a trend of increase in incidence. Therapeutic options and efficacy for liver cancer have been limited and the 5-year survival rate is less than 7% in the Unite States. The study was conducted to establish a histoculture system of human hepatocellular carcinomas (HCC) for biological and pharmacological studies and to determine the efficacy of anticancer drugs with the established HCC histocultures. Patient HCC tissues freshly obtained after surgeries were prepared and histocultured. The histocultured HCC were treated with doxorubicin and paclitaxel of various concentrations for 96-h. Upon drug treatments, the activity of tumor cell proliferation and extent of cell death induction were measured and changes of the alpha-fetoprotein levels in the culture medium were determined. We demonstrated that human HCC can be successfully cultured in a 3-dimensional histoculture system and used for pharmacological studies. Doxorubicin and paclitaxel showed concentration-dependent activities in anti-proliferation and cell death induction against the human HCC. Inhibitory effects of both drugs on alpha-fetoprotein production of the cultured HCC were in agreement with their anti-proliferative effects. Exposure time-dependent antitumoral effects of paclitaxel treatments at 3-, 24-, and 96-h against the histocultured HCC PLC/PRF/5 xenograft tumors were also observed. In conclusion, we have demonstrated a histoculture system for patient HCC and it can be utilized in selection of active drugs prior to treatments in patients and in evaluation of new agents against HCC, for which therapeutic agents are in desperate needs worldwide. PMID:17206490

Chuu, Jiunn-Jye; Liu, Jacqueline Ming; Tsou, Mei-Hua; Huang, Chen-Lung; Chen, Ching-Ping; Wang, Hsin-Sheng; Chen, Chiung-Tong

2007-03-01

309

Characterization and in vitro assessment of paclitaxel loaded lipid nanoparticles formulated using modified solvent injection technique.  

PubMed

This study investigates the design and characterization of solid lipid nanoparticles (SLNs) containing paclitaxel fabricated by a modified solvent injection technique using stearic acid as lipid and stabilized by a mixture of surfactants, for future evaluation of this colloidal carrier system for the oral delivery of paclitaxel, devoid of the side effects of Cremophor EL. SLN formulations of paclitaxel stabilized by mixture of surfactants i.e. lecithin/poloxamer 188 were developed with smaller size and narrow size distribution. The paclitaxel-loaded SLNs exhibited spherical shape with smooth surface as analyzed by transmission electron microscopy (TEM). The average particle size obtained through this method was found to be approximately 113 nm. The zeta potential was between -32 and -39 mV with poloxamer 188. Encapsulation efficiencies of about 72.18 +/- 3.7 and 89.0 +/- 2.4% were achieved using 0.05 and 0.25 mmol of paclitaxel, respectively. Paclitaxel showed a sustained in vitro release profile and was found to follow Higuchi kinetic equations. In vitro cytotoxicity assay confirmed that paclitxel entrapped in SLNs showed higher cytotoxicity against cultured hepatocelluler carcinoma cells than paclitaxel alone. The modified solvent injection technique used in this research proved to be a simple, easily available and effective method to produce SLNs and could be used for controlled delivery of different lipophilic drugs for cancer chemotherapy. PMID:19530440

Pandita, D; Ahuja, A; Velpandian, T; Lather, V; Dutta, T; Khar, R K

2009-05-01

310

Angiogenesis inhibition in the in vivo antineoplastic effect of manumycin and paclitaxel against anaplastic thyroid carcinoma.  

PubMed

Our laboratory has investigated the anticancer effects of combined manumycin (a farnesyltransferase inhibitor) and paclitaxel (a microtubule inhibitor) against anaplastic thyroid carcinoma (ATC). In this study we reported the in vivo efficacy of this combination against ATC cells and the lack of toxicity of this treatment in mice. We observed that manumycin-treated tumors looked paler than both control and paclitaxel-treated tumors. We hypothesized that angiogenesis inhibition mediated part of the in vivo effect of manumycin. This hypothesis was supported by the findings that manumycin significantly inhibited angiogenesis (as directly demonstrated by measurement of hemoglobin content and vascular area) in Matrigel implanted into mice, that manumycin decreased the vascular endothelial growth factor in hypoxic ATC cells, and that both manumycin and paclitaxel inhibited endothelial cell proliferation. Interestingly, inhibition of endothelial tubule formation in Matrigel was enhanced by combining manumycin and paclitaxel. As angiogenesis and tumor growth are continuous processes, we investigated the effect of sustained delivery of manumycin and found that paclitaxel plus slow release manumycin (13.25 mg/kg x week) inhibited ATC xenografts more than paclitaxel plus intermittent manumycin (15 mg/kg x week). In conclusion, manumycin plus paclitaxel is an effective combination against ATC, and inhibition of angiogenesis plays a role in the antineoplastic effect of this combination. PMID:11297616

Xu, G; Pan, J; Martin, C; Yeung, S C

2001-04-01

311

Role of tumor necrosis factor alpha-induced protein 1 in paclitaxel resistance.  

PubMed

Paclitaxel has been extensively used as an antitumor drug to treat a broad range of epithelial cancers, including breast and cervical cancers. However, the efficacy of this drug is greatly limited by the development of acquired resistance. Identification of the underlying resistance mechanisms may inform the development of new therapies that elicit long-term response of tumors to paclitaxel treatment. Here we report that increased expression of TNFAIP1 (tumor necrosis factor alpha-induced protein 1) confers acquired resistance to paclitaxel. TNFAIP1 is shown to compete with paclitaxel for binding to ?-tubulin, thereby preventing paclitaxel-induced tubulin polymerization, cell cycle arrest and ultimate cell death. We also show that expression of TNFAIP1 is regulated by the transcriptional factor Sp1. In a xenograft mouse model, increased expression of TNFAIP1 decreases, whereas knockdown of TNFAIP1 increases tumor response to paclitaxel. Therefore, these results reveal tnfaip1 as a novel paclitaxel-resistance associated gene and suggest that TNFAIP1 may represent a valuable therapeutic target for the treatment of cancer. PMID:23912453

Zhu, Y; Yao, Z; Wu, Z; Mei, Y; Wu, M

2014-06-19

312

Vorinostat increases carboplatin and paclitaxel activity in non-small cell lung cancer cells  

PubMed Central

We observed a 53% response rate in non-small cell lung cancer (NSCLC) patients treated with vorinostat plus paclitaxel/carboplatin in a Phase I trial. Studies were undertaken to investigate the mechanism (s) underlying this activity. Growth inhibition was assessed in NSCLC cells by MTT assay after 72 h of continuous drug exposure. Vorinostat (1 µM) inhibited growth by: 17±7% in A549, 28±6% in 128-88T, 39±8% in Calu1, and 41±7% in 201T cells. Vorinostat addition to carboplatin or paclitaxel led to significantly greater growth inhibition than chemotherapy alone in all 4 cell lines. Vorinostat (1 µM) synergistically increased the growth inhibitory effects of carboplatin/paclitaxel in 128-88T cells. When colony formation was measured after drug withdrawal, vorinostat significantly increased the effects of carboplatin but not paclitaxel. The % colony formation was: control 100%; 1 µM vorinostat 83% ± 10%; 5 µM carboplatin, 41% ± 11%; carboplatin/vorinostat, 8% ± 4%; 2 nM paclitaxel, 53% ± 11%; paclitaxel/vorinostat 46% ± 21%. In A549 and 128-88T, vorinostat potentiated carboplatin induction of gamma-H2AX (a DNA damage marker) and increased ?-tubulin acetylation (a marker for stabilized mictrotubules). In A549, combination of vorinostat with paclitaxel resulted in a synergistic increase in ?-tubulin acetylation, which reversed upon drug wash-out. We conclude that vorinostat interacts favorably with carboplatin and paclitaxel in NSCLC cells, which may explain the provocative response observed in our clinical trial. This likely involves a vorinostat-mediated irreversible increase in DNA damage in the case of carboplatin and a reversible increase in microtubule stability in the case of paclitaxel.

Owonikoko, Taofeek K.; Ramalingam, Suresh S.; Kanterewicz, Beatriz; Balius, Trent; Belani, Chandra P.; Hershberger, Pamela A.

2009-01-01

313

Effect of maceligan on the systemic exposure of paclitaxel: in vitro and in vivo evaluation.  

PubMed

This study investigated the effect of macelignan on the P-glycoprotein-mediated drug efflux as well as CYP3A4-mediated drug metabolism and subsequently its in vivo implication on the bioavailability of paclitaxel. The inhibition effect of macelignan on the CYP3A4-mediated metabolism was negligible over the concentration range of 0.01-100muM in rat liver microsome while approximately 33% inhibition was observed at 100muM in human liver microsome, implying that the interaction of macelignan with CYP3A4 might be insignificant at the physiologically achievable concentrations. In contrast, macelignan (20muM) increased the cellular accumulation of paclitaxel by approximately 1.7-fold in NCI/ADR-RES cells overexpressing P-gp, while it did not alter the cellular accumulation of paclitaxel in OVCAR-8 cells lacking P-gp. The effect of macelignan on the systemic exposure of paclitaxel was also examined in rats after the intravenous and oral administration of paclitaxel in the presence and the absence of macelignan. The concurrent use of macelignan significantly (p<0.05) enhanced the oral exposure of paclitaxel in rats while it did not affect the intravenous pharmacokinetics of paclitaxel, implying that macelignan might be more effective to improve the intestinal absorption rather than reducing hepatic elimination. In conclusion, macelignan appeared to be effective to improve the cellular accumulation as well as oral exposure of paclitaxel mainly via the inhibition of P-gp-mediated cellular efflux, suggesting that the concomitant use of macelignan may provide a therapeutic benefit in improving the anticancer efficacy of paclitaxel. PMID:20600879

Qiang, Fu; Lee, Beom-Jin; Ha, Ilho; Kang, Keon Wook; Woo, Eun-Rhan; Han, Hyo-Kyung

2010-10-01

314

Development and validation of a method to determine the unbound paclitaxel fraction in human plasma.  

PubMed

Paclitaxel is pharmaceutically formulated in a mixture of Cremophor EL and ethanol (1:1, v/v). The unbound fraction of the anticancer drug paclitaxel in plasma is dependent on both plasma protein binding and entrapment in Cremophor EL micelles. We have developed a simple and reproducible method for the quantification of the unbound paclitaxel fraction in human plasma. Human plasma was spiked with [3H]paclitaxel and [14C]glucose (unbound reference) and incubated at 37 degrees C for 30 min. Plasma ultrafiltrate was prepared by a micropartition system (MPS-1) and collected in a sample cup containing 100 microl of plasma to prevent the loss of paclitaxel due to adsorption. The radionuclides were separated after combustion of the biological samples using a sample oxidizer and the radioactivity was determined by liquid scintillation counting. The unbound fraction of paclitaxel was calculated by dividing the ratios of 3H and 14C in plasma ultrafiltrate and in plasma. The method was thoroughly validated using human plasma spiked with pharmacologically relevant concentrations of paclitaxel (10-1000 ng/ml) and Cremophor EL (0.25-2.0%). The method was precise, with a within-day precision ranging from 3.9 to 11.0% and a between-day precision ranging from 5.8 to 13.1%. In patient plasma with low serum albumin values containing 1% of Cremophor EL, the unbound fraction appeared to be significantly higher than that in plasma with normal albumin values. The determination of the unbound fraction of paclitaxel proved to be stable during a 10-week storage at -20 degrees C. Furthermore, the assay was applicable in patient samples. This assay can be used to determine the unbound fraction of paclitaxel in plasma. Moreover, its design should allow the determination of the unbound concentrations of other hydrophobic drugs. PMID:14654039

van den Bongard, H J G Desirée; Kemper, E Marleen; van Tellingen, Olaf; Rosing, Hilde; Mathôt, Ron A A; Schellens, Jan H M; Beijnen, Jos H

2004-01-01

315

Taxol induces caspase-independent cytoplasmic vacuolization and cell death through endoplasmic reticulum (ER) swelling in ASTC-a-1 cells.  

PubMed

High concentration of taxol was found to induce programmed cell death (PCD) and cytoplasm vacuolization in human lung adenocarcinoma (ASTC-a-1) cells. To elucidate the relationship between the PCD and cytoplasm vacuolization, confocal fluorescence microscopy was performed on the cytoplasm vacuolization, endoplasmic reticulum (ER) and mitochondria swelling after taxol treatment in living cells. erRFP plasmid was used to probe the ER distribution, and SCAT3 plasmid was used to monitor the caspase-3 activation in living cells. Our results showed that taxol induced concentration-dependent and caspases-independent cytoplasm vacuolization and cell death through ER and mitochondria swelling. Live confocal imaging of ASTC-a-1 cells stably expressing SCAT3 further verified that taxol-induced cytoplasm vacuolization and cell death was caspase-3-independent. In conclusion, we found for the first time that taxol induces a paraptosis-like PCD in the ASTC-a-1 cells by cytoplasm vacuolization due to the swelling of both ER and mitochondria without activating the caspase enzymes. PMID:18547714

Chen, Tong-sheng; Wang, Xiao-ping; Sun, Lei; Wang, Long-xiang; Xing, Da; Mok, Martin

2008-10-18

316

Salvage chemotherapy with carboplatin and paclitaxel for cisplatin-resistant thymic carcinoma--three cases.  

PubMed

The optimal chemotherapeutic regimen for thymic carcinoma remains uncertain and the utility of salvage therapy has also not been reported. Three cases of unresectable and locally advanced thymic carcinoma, resistant to prior chemotherapy with cisplatin are reported. These patients were treated with carboplatin and paclitaxel chemotherapy, as salvage chemotherapy. Although concomitant thoracic radiotherapy was performed in one patient, two showed a partial response and the other showed a minor response after carboplatin and paclitaxel chemotherapy. Thymic carcinoma is sensitive to platinum-based chemotherapy and paclitaxel appears to have significant activity against thymic carcinoma. PMID:17214351

Komatsu, Yoshimichi; Koizumi, Tomonobu; Tanabe, Tsuyoshi; Hatayama, Orie; Yasuo, Masanori; Okada, Mitsuyo; Yamamoto, Hiroshi; Kubo, Keishi; Sasabayashi, Mari; Tsunoda, Toshiyuki

2006-01-01

317

PACLITAXEL GELATIN NANOPARTICLES FOR INTRAVESICAL BLADDER CANCER THERAPY  

PubMed Central

Purpose We have shown that inadequate drug delivery to tumor cells is a major cause of failures in intravesical therapy of nonmuscle-invading bladder cancer. This is partly due to the dilution of drug concentration by urine production during treatment. To address this problem, we developed gelatin nanoparticles of paclitaxel (PNP) designed to yield constant drug concentrations. The hypothesis that constant, therapeutic concentrations in urine, bladder tissue and tumors can be attained was evaluated in dogs. Materials and methods We studied the drug release from PNP in culture medium in vitro. In vivo studies were performed in tumor-free dogs and in pet dogs with naturally occurring transitional cell carcinoma, where the pharmacokinetics (plasma, urine and tumors) of PNP was determined. Results The release of paclitaxel from PNP in vitro and in vivo was rate-limited by the drug solubility in aqueous medium. This property yielded constant drug concentrations independent of changes in the urine volume over the 2-hr treatment. Intravesical PNP showed low systemic absorption and favorable bladder tissue/tumor targeting and retention properties, with pharmacologically active concentrations retained in tumors for at least 1 week. Conclusions The constant drug release from PNP may overcome the problem of drug dilution by newly produced urine and the sustained drug levels in tumors may reduce the treatment frequency.

Lu, Ze; Yeh, Teng-Kuang; Wang, Jie; Chen, Ling; Lyness, Greg; Xin, Yan; Wientjes, M. Guillaume; Bergdall, Valerie; Couto, Guillermo; Alvarez-Berger, Francisco; Kosarek, Carrie E.; Au, Jessie L-S.

2013-01-01

318

Paclitaxel-loaded composite fibers: microstructure and emulsion stability.  

PubMed

New core/shell fiber structures loaded with paclitaxel were developed and studied. These composite fibers are ideal for forming thin, delicate, biomedically important structures for various applications. Possible applications include fiber-based endovascular stents that mechanically support blood vessels while delivering drugs for preventing restenosis directly to the blood vessel wall, or drug delivery systems for cancer treatment. The core/shell fiber structures were formed by "coating" nylon fibers with porous paclitaxel-containing poly(DL-lactic-co-glycolic acid) structures. Shell preparation ("coating") was performed by freeze-drying water in oil emulsions. The present study focused on the effects of the emulsion's formulation (composition) and processing conditions on the porous shell structure, which actually reflects the emulsion's stability and also the drug release profile from the fibers. In general, extremely porous "shell" structures were obtained with good adhesion to the core fiber. An increase in the emulsion's drug content and copolymer composition demonstrated a significant effect on pore size and distribution, because of enhanced emulsion instability, whereas the homogenization rate and duration had only a slight effect on the pores' microstructure. The thermodynamic parameters in the studied system are thus more important than the kinetic parameters in determining the emulsion's stability and the shell's porous structure. PMID:17117472

Kraitzer, Amir; Zilberman, Meital

2007-05-01

319

Paclitaxel loaded PEGylated gleceryl monooleate based nanoparticulate carriers in chemotherapy.  

PubMed

A PEGylated drug delivery system of paclitaxel (PTX), based on glyceryl monooleate (GMO) was prepared by optimizing various parameters to explore its potential in anticancer therapy. The prepared system was characterized through polarized light microscopy, TEM, AFM and SAXS to reveal its liquid crystalline nature. As GMO based LCNPs exhibit high hemolytic toxicity and faster release of entrapped drug (66.2 ± 2.5% in 24 h), PEGylation strategy was utilized to increase the hemocompatibility (reduction in hemolysis from 60.3 ± 10.2 to 4.4 ± 1.3%) and control the release of PTX (43.6 ± 3.2% released in 24 h). The cytotoxic potential and cellular uptake was assessed in MCF-7 cell lines. Further, biodistribution studies were carried out in EAT (Ehrlich Ascites tumor) bearing mice using (99m)Tc-(Technetium radionuclide) labeled formulations and an enhanced circulation time and tumor accumulation (14 and 8 times, respectively) were observed with PEGylated carriers over plain ones, at 24 h. Finally, tumor growth inhibition experiment was performed and after 15 days, control group exhibited 15 times enhancement in tumor volume, while plain and PEGylated systems exhibited only 8 and 4 times enhancement, respectively, as compared to initial tumor volume. The results suggest that PEGylation enhances the hemocompatibility and efficacy of GMO based system that may serve as an efficient i.v. delivery vehicle for paclitaxel. PMID:22809646

Jain, Vikas; Swarnakar, Nitin K; Mishra, Prabhat R; Verma, Ashwni; Kaul, Ankur; Mishra, Anil K; Jain, Narendra K

2012-10-01

320

Population analysis of a 24-h paclitaxel infusion in advanced endometrial cancer: a gynaecological oncology group study  

PubMed Central

Aims To examine determinants of paclitaxel disposition and the association between paclitaxel exposure and toxicity or survival in patients with advanced stage or recurrent endometrial cancer treated with doxorubicin plus paclitaxel. Methods A limited sampling scheme was used to examine the population pharmacokinetics of paclitaxel in 160 patients from one arm of a randomized Phase III trial of doxorubicin plus paclitaxel or cisplatin. Four plasma samples per patient were collected at approximately 0, 3, 22 and 27 h after the first 24-h infusion of paclitaxel and submitted to the Gynecological Oncology Group (GOG) Pharmacology Core Laboratory. Total paclitaxel concentrations were quantified by LC/MS and paclitaxel disposition was examined using NONMEM. Paclitaxel exposure was evaluated for associations with toxicity or survival. Results Patient weight, age and serum glutamic-oxaloacetic transaminase level were determinants of paclitaxel clearance (clearance increased 0.437 l h?1 kg?1; decreased 0.223 l h?1 year?1 and 0.105 l h?1 IU?1). Bayesian shrinkage was minimal for this parameter. In different measures of paclitaxel exposure, AUC was most predictive of toxicity, with higher AUC associated with granulocytopenia [probability of 1% at AUC = 1 to 22% at AUC = 4 µg l?1 h?1 for performance status (PS) = 0]. PS was more strongly associated with survival than disease stage and higher paclitaxel AUC was associated with worse survival irrespective of PS and stage. Conclusions Paclitaxel AUC is an independent predictor of granulocytopenia and survival in patients with advanced stage or recurrent endometrial cancer. Future studies are needed to validate the latter finding. This study confirms the appropriateness of evaluating pharmacokinetics and pharmacodynamics in multicentre oncology trials.

Mould, Diane R; Fleming, Gini F; Darcy, Kathleen M; Spriggs, David

2006-01-01

321

Identification of a novel function of TWIST, a bHLH protein, in the development of acquired taxol resistance in human cancer cells.  

PubMed

Taxol is one of the widely used chemotherapeutic drugs against many types of human cancer. While it is considered as one of the most effective anticancer drugs, treatment failure often occurs due to development of acquired resistance. Therefore, it is important to understand the molecular mechanisms responsible for the development of drug resistance. Although it is generally believed that taxol induces cell death through interfering with microtubules leading to mitotic arrest, recent evidence has suggested that taxol-induced cell death also occurs through pathways independent of either microtubule or mitotic arrest. In this study, we report the identification of a novel role for TWIST, a basic helix-loop-helix protein, which plays a central role in cell type determination and differentiation, during generation of acquired resistance to taxol in a nasopharyngeal carcinoma cell line, HNE1-T3, using comparative genome hybridization (CGH) and subsequent RT-PCR and Western blotting. We found that upregulation of TWIST was associated with cellular resistance to taxol but not other drugs with different mechanisms of action. The fact that increased TWIST protein levels were also associated with another microtubule-targeting anticancer drug, vincristine, in four types of human cancer including nasopharyngeal, bladder, ovarian and prostate, indicates that it may play a central role in the resistance to microtubule-disrupting agents. In addition, ectopic expression of TWIST into human cancer cells also led to increased resistance to both taxol and vincristine. Our results indicate a novel mechanism that leads to resistance to microtubule-disrupting anticancer drugs through upregulation of TWIST. Our evidence provides a therapeutic strategy to overcome acquired resistance through inactivation of TWIST expression in human cancer. PMID:14724576

Wang, Xianghong; Ling, Ming Tat; Guan, Xin-Yuan; Tsao, Sai Wah; Cheung, Hiu Wing; Lee, Davy Tak; Wong, Yong Chuan

2004-01-15

322

Poly-cyclodextrin and poly-paclitaxel nano-assembly for anticancer therapy  

NASA Astrophysics Data System (ADS)

Effective anticancer therapy can be achieved by designing a targeted drug-delivery system with high stability during circulation and efficient uptake by the target tumour cancer cells. We report here a novel nano-assembled drug-delivery system, formed by multivalent host–guest interactions between a polymer–cyclodextrin conjugate and a polymer–paclitaxel conjugate. The multivalent inclusion complexes confer high stability to the nano-assembly, which efficiently delivers paclitaxel into the targeted cancer cells via both passive and active targeting mechanisms. The ester linkages between paclitaxel and the polymer backbone permit efficient release of paclitaxel within the cell by degradation. This novel targeted nano-assembly exhibits significant antitumour activity in a mouse tumour model. The strategy established in this study also provides knowledge for the development of advanced anticancer drug delivery.

Namgung, Ran; Mi Lee, Yeong; Kim, Jihoon; Jang, Yuna; Lee, Byung-Heon; Kim, In-San; Sokkar, Pandian; Rhee, Young Min; Hoffman, Allan S.; Kim, Won Jong

2014-05-01

323

Differential regulation of calcium homeostasis in adenocarcinoma cell line A549 and its Taxol-resistant subclone  

PubMed Central

Drug resistance is a fundamental problem in cancer chemotherapy. Intracellular calcium concentration ([Ca2+]i) may play a role in the development of chemoresistance. We investigated the regulatory role of [Ca2+]i in Taxol resistance in the non-small-cell lung cancer cell line A549 and its chemoresistant subclone A549-T24. Measurement of cytosolic calcium ([Ca2+]c) in single cells and cell populations revealed similar levels of basal calcium in the two cell lines. However, a reduced response to thapsigargin (a sarcoplasmic/endoplasmic reticulum Ca2+-ATPase (SERCA) inhibitor) in A549-T24 cells compared to the parent cell line suggested a lower ER Ca2+ content in these cells. mRNA expression of SERCA2b and SERCA3, major Ca2+ pumps involved in ER Ca2+ homeostasis, did not significantly differ between the two cell lines, as revealed by RT–PCR. An altered calcium influx pathway in the Taxol-resistant cell line was observed. Modulation of the ER calcium pools using CMC (4-chloro-m-cresol) and ATP revealed lower ryanodine receptor (RyR) and IP3 receptor (IP3R)-sensitive Ca2+ stores in the chemoresistant cell line. Western blot and RT–PCR studies suggested that A549-T24 cells expressed higher levels of the antiapoptotic protein Bcl-2 and the calcium-binding protein sorcin, respectively, in comparison to the parent cell line. Both of these proteins have been previously implicated in chemoresistance, in part, due to their ability to modulate [Ca2+]i. These results suggest that altered intracellular calcium homeostasis may contribute to the Taxol-resistant phenotype.

Padar, Shanthala; van Breemen, Cornelis; Thomas, David W; Uchizono, James A; Livesey, John C; Rahimian, Roshanak

2004-01-01

324

Docetaxel and paclitaxel inhibit DNA-adduct formation and intracellular accumulation of cisplatin in human leukocytes  

Microsoft Academic Search

The purpose of this study was to determine the mechanism of the pharmacodynamic interaction between docetaxel\\/paclitaxel\\u000a and cisplatin. Cisplatin-induced DNA-adducts and cisplatin accumulation were quantitated in peripheral blood leukocytes (WBC).\\u000a The WBC were obtained from patients treated with docetaxel or paclitaxel in phase I\\/II studies and were incubated in vitro\\u000a with cisplatin. In addition, blank whole-blood samples were obtained from

Jianguo Ma; Jaap Verweij; Andre S. T. Planting; Herman J. Kolker; Walter J. Loos; Maureen de Boer-Dennert; Maria E. L. van der Burg; Gerrit Stoter; J. H. M. Schellens

1996-01-01

325

Paclitaxel administration and its effects on clinically relevant human cancer and non cancer cell lines  

Microsoft Academic Search

Comparisons of the effects of clinically relevant concentrations of the anticancer agent paclitaxel on growth, viability, and apoptosis were determined using in vitro human cell cultures. Growth of the cervical cancer cell line, HeLa-S3, was significantly reduced, and apoptotic index was significantly increased, after 24 h in cultures treated with 12 nM paclitaxel. In contrast, hepatic carcinoma (HEpG2) cells capable

Gretchen McAuliffe; Louis Roberts; Susan Roberts

2002-01-01

326

Comparison of two different paclitaxel-coated balloon catheters in the porcine coronary restenosis model  

Microsoft Academic Search

Background  Drug-eluting balloon (DEB) catheters coated with paclitaxel in a water-soluble matrix have shown beneficial effects in the\\u000a treatment and prevention of restenosis in the porcine coronary overstretch model and in clinical trials. Adherence of paclitaxel,\\u000a same dose, on another recently introduced coated percutaneous coronary intervention (PCI) catheter (DIOR®) is mediated by a roughened balloon surface. Only scarce experimental and clinical

Bodo Cremers; Melanie Biedermann; Dirk Mahnkopf; Michael Böhm; Bruno Scheller

2009-01-01

327

Paclitaxel-hyaluronic nanoconjugates prolong overall survival in a preclinical brain metastases of breast cancer model.  

PubMed

Brain (central nervous system; CNS) metastases pose a life-threatening problem for women with advanced metastatic breast cancer. It has recently been shown that the vasculature within preclinical brain metastasis model markedly restricts paclitaxel delivery in approximately 90% of CNS lesions. Therefore to improve efficacy, we have developed an ultra-small hyaluronic acid (HA) paclitaxel nanoconjugate (?5 kDa) that can passively diffuse across the leaky blood-tumor barrier and then be taken up into cancer cells (MDA-MB-231Br) via CD44 receptor-mediated endocytocis. Using CD44 receptor-mediated endocytosis as an uptake mechanism, HA-paclitaxel was able to bypass p-glycoprotein-mediated efflux on the surface of the cancer cells. In vitro cytoxicity of the conjugate and free paclitaxel were similar in that they (i) both caused cell-cycle arrest in the G2-M phase, (ii) showed similar degrees of apoptosis induction (cleaved caspase), and (iii) had similar IC50 values when compared with paclitaxel in MTT assay. A preclinical model of brain metastases of breast cancer using intracardiac injections of Luc-2 transfected MDA-MB-231Br cells was used to evaluate in vivo efficacy of the nanoconjugate. The animals administered with HA-paclitaxel nanoconjugate had significantly longer overall survival compared with the control and the paclitaxel-treated group (P < 0.05). This study suggests that the small molecular weight HA-paclitaxel nanoconjugates can improve standard chemotherapeutic drug efficacy in a preclinical model of brain metastases of breast cancer. PMID:24002934

Mittapalli, Rajendar K; Liu, Xinli; Adkins, Chris E; Nounou, Mohamed I; Bohn, Kaci A; Terrell, Tori B; Qhattal, Hussaini S; Geldenhuys, Werner J; Palmieri, Diane; Steeg, Patricia S; Smith, Quentin R; Lockman, Paul R

2013-11-01

328

Potentiation of ovarian OCa1 tumor radioresponse by poly (L-glutamic acid)-paclitaxel conjugate  

Microsoft Academic Search

Purpose: It has been shown that paclitaxel (TXL) can strongly enhance tumor cells’ sensitivity to radiation. We examined whether the radiosensitizing effect of paclitaxel can be further enhanced when it is delivered systemically as a polymer-drug conjugate that provides enhanced tumor uptake and prolonged release of TXL in the tumor.Methods and Materials: C3Hf\\/Kam mice bearing 8-mm murine ovarian OCa-1 tumors

Chun Li; Shi Ke; Qing-Ping Wu; Wayne Tansey; Nancy Hunter; Lara M Buchmiller; Luka Milas; Chusilp Charnsangavej; Sidney Wallace

2000-01-01

329

Development of nonionic surfactant\\/phospholipid o\\/w emulsion as a paclitaxel delivery system  

Microsoft Academic Search

Paclitaxel is an anticancer agent with low aqueous solubility. More extensive clinical use of this drug is somewhat delayed due to lack of appropriate delivery vehicles. An attempt was made to adopt an o\\/w emulsion as the drug carrier which incorporated paclitaxel in the triacylglycerol stabilized by a mixed-emulsifier system. A suitable formulation was found in this study: 0.75 mg\\/ml

Pei Kan; Zhi-Beng Chen; Chau-Jen Lee; I-Ming Chu

1999-01-01

330

PHARMACOKINETICS OF PACLITAXEL ADMINISTERED AS A 3HOUR OR 96HOUR INFUSION  

Microsoft Academic Search

Aim: To investigate the pharmacokinetics of paclitaxel (PaxeneTM) administered to patients with advanced breast or ovarian cancer and to document safety and anti-tumour activity in this study population. Patients and methods: Patients with advanced breast or ovarian cancer were accrued to two clinical studies. Paclitaxel (PaxeneTM) was administered as a 3-h 175 mg m?2or as a 96-h 140 mg m?2(105

VINODH R. NANNAN PANDAY; WIM W. TEN BOKKEL HUININK; JAN B. VERMORKEN; HILDE ROSING; FRANCISCA J. KOOPMAN; MARTHA SWART; JAN H. M. SCHELLENS; JOS H. BEIJNEN

1999-01-01

331

Synergy of a Herpes OncolyticVirus and Paclitaxel for Anaplastic Thyroid Cancer  

PubMed Central

Purpose Novel therapeutic regimens are needed to improve the dismal outcomes of patients with anaplastic thyroid cancer (ATC). Oncolytic herpes simplex virus have shown promising activity against human ATC. We studied the application of oncolytic herpes simplex virus (G207 and NV1023) in combination with currently used chemotherapeutic drugs (paclitaxel and doxorubicin) for the treatment of ATC. Experimental Design and Results All four agents showed dose-response cytotoxicity in vitro for the human ATC cell lines KAT4 and DRO90-1. G207, combined with paclitaxel, showed synergistic cytotoxicity. Chou-Talalay combination indices ranged from 0.56 to 0.66 for KAT4, and 0.68 to 0.74 for DRO90-1at higher affected fractions. Paclitaxel did not enhance G207 viral entry and early gene expression or G207 viral replication. Paclitaxel combined with G207 compared with single-agent treatment or controls showed significantly increased microtubule acetylation, mitotic arrest, aberrant chromatid separation, inhibition of metaphase to anaphase progression, and apoptosis. A single i.t. injection of G207 combined with biweekly i.p. paclitaxel injections in athymic nude mice bearing KAT4 flank tumors showed significantly reduced mean tumor volume (74 F 38 mm3) compared with G207 alone (388 F 109 mm3), paclitaxel alone (439 F 137 mm3), and control (520 F 160 mm3) groups at 16 days. There was no morbidity in vivo attributable to therapy. Conclusions Mechanisms of paclitaxel antitumoral activity, including microtubule acetylation, mitotic block, and apoptosis, were enhanced by G207, which also has direct oncolytic effects. Combination of G207 and paclitaxel therapy is synergistic in treating ATC and holds promise for patients with this fatal disease.

Lin, Shu-Fu; Gao, Sizhi Paul; Price, Daniel L.; Li, Sen; Chou, Ting-Chao; Singh, Paramjeet; Huang, Yu-Yao; Fong, Yuman; Wong, Richard J.

2009-01-01

332

A phase II\\/pharmacokinetic trial of high-dose progesterone in combination with paclitaxel  

Microsoft Academic Search

Purpose: The purpose of this study was to investigate the effect of high-dose progesterone, an inhibitor of P glycoprotein, on the\\u000a pharmacokinetics and toxicity of paclitaxel. Patients and methods: A total of 29 patients with various tumors were treated with single-agent paclitaxel (125?mg\\/m2 administered over 3?h once every 3 weeks) until progression of disease, at which point high-dose progesterone (3?g

S. Aebi; T. W. Schnider; G. Los; D. D. Heath; D. Darrah; S. Kirmani; E. F. McClay; H. D'Agostino; S. C. Plaxe; D. Fink; M. M. De las Alas; S. B. Howell; R. D. Christen

1999-01-01

333

Paeonol reverses paclitaxel resistance in human breast cancer cells by regulating the expression of transgelin 2.  

PubMed

Paclitaxel (PTX) is a first-line antineoplastic drug that is commonly used in clinical chemotherapy for breast cancer treatment. However, the occurrence of drug resistance in chemotherapeutic treatment has greatly restricted its use. There is thus an urgent need to find ways of reversing paclitaxel chemotherapy resistance in breast cancer. Plant-derived agents have great potential in preventing the onset of the carcinogenic process and enhancing the efficacy of mainstream antitumor drugs. Paeonol, a main compound derived from the root bark of Paeonia suffruticosa, has various biological activities, and is reported to have reversal drug resistance effects. This study established a paclitaxel-resistant human breast cancer cell line (MCF-7/PTX) and applied the dual-luciferase reporter gene assay, MTT assay, flow cytometry, transfection assay, Western blotting and the quantitative real-time polymerase chain reaction (qRT-PCR) to investigate the reversing effects of paeonol and its underlying mechanisms. It was found that transgelin 2 may mediate the resistance of MCF-7/PTX cells to paclitaxel by up-regulating the expressions of the adenosine-triphosphate binding cassette transporter proteins, including P-glycoprotein (P-gp), multidrug resistance associated protein 1 (MRP1), and breast cancer resistance protein (BCRP). Furthermore, the ability of paeonol to reverse paclitaxel resistance in breast cancer was confirmed, with a superior 8.2-fold reversal index. In addition, this study found that paeonol down-regulated the transgelin 2-mediated paclitaxel resistance by reducing the expressions of P-gp, MRP1, and BCRP in MCF-7/PTX cells. These results not only provide insight into the potential application of paeonol to the reversal of paclitaxel resistance, thus facilitating the sensitivity of breast cancer chemotherapy, but also highlight a potential role of transgelin 2 in the development of paclitaxel resistance in breast cancer. PMID:24680370

Cai, Jiangxia; Chen, Siying; Zhang, Weipeng; Hu, Sasa; Lu, Jun; Xing, Jianfeng; Dong, Yalin

2014-06-15

334

Antiangiogenic Activity of Sterically Stabilized Liposomes Containing Paclitaxel (SSL-PTX): In Vitro and In Vivo  

Microsoft Academic Search

The purpose of this present study was to evaluate the antiangiogenic activity of sterically stabilized liposomes containing\\u000a paclitaxel (SSL-PTX). The SSL-PTX was prepared by the thin-film method. The release of paclitaxel from SSL-PTX was analyzed\\u000a using a dialysis method. The effect of SSL-PTX on endothelial cell proliferation and migration was investigated in vitro. The antitumor and antiangiogenic activity of SSL-PTX

Yue Huang; Xiao-Mei Chen; Bing-Xiang Zhao; Xi-Yu Ke; Bo-Jun Zhao; Xin Zhao; Ying Wang; Xuan Zhang; Qiang Zhang

2010-01-01

335

Microtubule-associated protein tau: A marker of paclitaxel sensitivity in breast cancer  

Microsoft Academic Search

Breast cancers show variable sensitivity to paclitaxel. There is no diagnostic test to identify tumors that are sensitive to this drug. We used U133A chips to identify genes that are associated with pathologic complete response (pCR) to preoperative paclitaxel-containing chemotherapy in stage I-III breast cancer (n = 82). Tau was the most differentially expressed gene. Tumors with pCR had significantly

Roman Rouzier; Radhika Rajan; Peter Wagner; Kenneth R. Hess; David L. Gold; James Stec; Mark Ayers; Jeffrey S. Ross; Peter Zhang; Thomas A. Buchholz; Henry Kuerer; Marjorie Green; Banu Arun; Gabriel N. Hortobagyi; W. Fraser Symmans; Lajos Pusztai

2005-01-01

336

Agrobacterium tumefaciens-mediated genetic transformation of the Taxol-producing endophytic fungus Ozonium sp EFY21.  

PubMed

An efficient Agrobacterium tumefaciens-mediated genetic transformation method was successfully established for a newly isolated Taxol-producing fungus, Ozonium sp EFY21. A specific hygromycin B resistance expression vector, pCAMBIA1304'AN7-1, was constructed for fungal transformation. Key factors affecting transformation efficiency were thoroughly investigated and optimized. PCR amplification and Southern hybridization were used to verify the transformation events. This study should pave the way for future genetic modification studies of Ozonium sp EFY21. PMID:24065647

Liu, L; Wei, Y M; Zhou, X W; Lin, J; Sun, X F; Tang, K X

2013-01-01

337

Physico chemical characterization of a novel anti-cancer agent and its comparison to Taxol(®).  

PubMed

Every year several thousand compounds are screened for their anti-cancer activity by a general test procedure amongst which only few selected move past the in vitro screening process. This may be due to the intrinsic property of the drug substance. Therefore, a complete physicochemical characterization of a New Chemical Entity (NCE) is essential to understand the effect of these properties on the in vitro and possibly in vivo behavior of these compounds. Various physicochemical properties such as dissociation constant, octanol-water partition co-efficient, pH solubility, stability, thermal characterization and membrane permeability were evaluated for a novel tubulin-binding agent JCA112 and were compared to that of Taxol(®). The drug exhibited a pKa value of 10.9, log P value of 2.3, pH dependent solubility, and low artificial membrane permeability. Stability of the drug substance in the in vitro screening media suggested a significant degradation during the 48-hour study duration. The results demonstrate that due to low aqueous solubility, limited membrane permeability and due to insufficient stability of JCA112 in the in vitro screening media, the drug exhibited limited anti-cancer activity. Along with challenging physicochemical characteristics, a generalization of the in vitro testing procedure may also result in loss of important anti-cancer agents. As a result, a complete understanding of the physico-chemical properties of the drug leading to prototype formulation with acceptable physico-chemical properties may be required for successful in vitro screening. PMID:22339150

Shah, Amit K; Wyandt, Christy M; Stodghill, Steven P

2013-01-01

338

Nanosuspension delivery of paclitaxel to xenograft mice can alter drug disposition and anti-tumor activity  

PubMed Central

Paclitaxel is a common chemotherapeutic agent that is effective against various cancers. The poor aqueous solubility of paclitaxel necessitates a large percentage of Cremophor EL:ethanol (USP) in its commercial formulation which leads to hypersensitivity reactions in patients. We evaluate the use of a crystalline nanosuspension versus the USP formulation to deliver paclitaxel to tumor-bearing xenograft mice. Anti-tumor efficacy was assessed following intravenous administration of three 20 mg/kg doses of paclitaxel. Paclitaxel pharmacokinetics and tissue distribution were evaluated, and differences were observed between the two formulations. Plasma clearance and tissue to plasma ratio of mice that were dosed with the nanosuspension are approximately 33- and 11-fold higher compared to those of mice that were given the USP formulation. Despite a higher tumor to plasma ratio for the nanosuspension treatment group, absolute paclitaxel tumor exposure was higher for the USP group. Accordingly, a higher anti-tumor effect was observed in the xenograft mice that were dosed with the USP formulation (90% versus 42% tumor growth inhibition). This reduction in activity of nanoparticle formulation appeared to result from a slower than anticipated dissolution in vivo. This study illustrates a need for careful consideration of both dose and systemic solubility prior utilizing nanosuspension as a mode of intravenous delivery.

2014-01-01

339

nab-Paclitaxel: novel clinical and experimental evidence in pancreatic cancer.  

PubMed

The past few decades have seen virtually no treatment advances for patients with metastatic pancreatic cancer. Clinical hallmark features of pancreatic ductal adenocarcinoma (PDA) include late symptom onset, invasive growth, early liver and lymph node metastasis, and resistance to available chemotherapies. nab-Paclitaxel (Abraxane®) is generated through high-pressure homogenization of human albumin and conventional paclitaxel resulting in non-covalently bound, water-soluble albumin-paclitaxel particles with an approximate diameter of 130?nm. Results from the recently completed Metastatic Pancreatic Adenocarcinoma Trial (MPACT) (phase III trial) showed a significant survival benefit for patients treated with nab-paclitaxel in combination with gemcitabine, and this treatment regimen is currently being implemented in national and international guidelines for PDA patients. Therefore, this regimen provides a much needed vantage point of attack for this recalcitrant tumor offering potential new hope for our patients. Mechanisms such as stromal depletion, selective intratumoral accumulation, synergism with gemcitabine metabolism and secreted protein acidic and rich in cysteine (SPARC) mediated anti-tumor activity have been suggested for nab-paclitaxel. This review discusses the clinical and experimental advances of nab-paclitaxel in pancreatic cancer. PMID:24687799

Neesse, A; Michl, P; Tuveson, D A; Ellenrieder, V

2014-04-01

340

Pazopanib enhances paclitaxel-induced mitotic catastrophe in anaplastic thyroid cancer.  

PubMed

Anaplastic thyroid cancer (ATC) has perhaps the worst prognosis of any cancer, with a median survival of only about 5 months regardless of stage. Pazopanib monotherapy has promising clinical activity in differentiated thyroid cancers (generally attributed to vascular endothelial growth factor receptor inhibition), yet has less effective single-agent activity in ATC. We now report that combining pazopanib with microtubule inhibitors such as paclitaxel produced heightened and synergistic antitumor effects in ATC cells and xenografts that were associated with potentiated mitotic catastrophe. We hypothesized that combined effects may reflect enhanced paclitaxel-induced cytotoxicity mediated by cell cycle regulatory kinase inhibition by pazopanib. Indeed, pazopanib potently inhibited aurora A, with pazopanib/paclitaxel synergy recapitulated by aurora A short hairpin RNA knockdown or by specific aurora A pharmacological inhibition. Pazopanib/paclitaxel synergy was reversed by aurora A knockdown. Moreover, aurora A (but not B or C) message and protein levels were significantly increased in patient ATCs, and durable benefit resulted from pilot clinical translation of pazopanib/paclitaxel therapy in a patient with metastatic ATC. Collectively, these results suggest that the pazopanib/paclitaxel combination is a promising candidate therapeutic approach in ATC and that aurora A may represent a potentially viable therapeutic molecular target in ATC. PMID:23283368

Isham, Crescent R; Bossou, Ayoko R; Negron, Vivian; Fisher, Kelly E; Kumar, Rakesh; Marlow, Laura; Lingle, Wilma L; Smallridge, Robert C; Sherman, Eric J; Suman, Vera J; Copland, John A; Bible, Keith C

2013-01-01

341

Nanosuspension delivery of paclitaxel to xenograft mice can alter drug disposition and anti-tumor activity  

NASA Astrophysics Data System (ADS)

Paclitaxel is a common chemotherapeutic agent that is effective against various cancers. The poor aqueous solubility of paclitaxel necessitates a large percentage of Cremophor EL:ethanol (USP) in its commercial formulation which leads to hypersensitivity reactions in patients. We evaluate the use of a crystalline nanosuspension versus the USP formulation to deliver paclitaxel to tumor-bearing xenograft mice. Anti-tumor efficacy was assessed following intravenous administration of three 20 mg/kg doses of paclitaxel. Paclitaxel pharmacokinetics and tissue distribution were evaluated, and differences were observed between the two formulations. Plasma clearance and tissue to plasma ratio of mice that were dosed with the nanosuspension are approximately 33- and 11-fold higher compared to those of mice that were given the USP formulation. Despite a higher tumor to plasma ratio for the nanosuspension treatment group, absolute paclitaxel tumor exposure was higher for the USP group. Accordingly, a higher anti-tumor effect was observed in the xenograft mice that were dosed with the USP formulation (90% versus 42% tumor growth inhibition). This reduction in activity of nanoparticle formulation appeared to result from a slower than anticipated dissolution in vivo. This study illustrates a need for careful consideration of both dose and systemic solubility prior utilizing nanosuspension as a mode of intravenous delivery.

Chiang, Po-Chang; Gould, Stephen; Nannini, Michelle; Qin, Ann; Deng, Yuzhong; Arrazate, Alfonso; Kam, Kimberly R.; Ran, Yingqing; Wong, Harvey

2014-04-01

342

Nanoparticle albumin-bound paclitaxel for treatment of metastatic breast cancer.  

PubMed

Two taxanes, paclitaxel and docetaxel, are among the most widely used chemotherapeutic agents in solid tumor oncology, with efficacy against tumors of the breast, lung, head and neck, ovary, prostate, stomach and urothelium. The taxanes have been studied extensively and have been proven effective for treating early and advanced breast cancer. However, paclitaxel and docetaxel are both highly hydrophobic compounds, requiring synthetic solvents for parenteral administration. The solvents in commercially available preparations cause life-threatening toxic effects and decreased efficacy, and they are inconvenient to administer. Nanoparticle albumin-bound paclitaxel (nabP) is a novel, solvent-free formulation of paclitaxel. With nabP, in contrast to standard paclitaxel, life-threatening hypersensitivity reactions have not been observed, and it can be administered safely without steroid and antihistamine premedication. Furthermore, nabP exploits cellular and tumor transport mechanisms to preferentially target tumor cells. Data from phase III studies of metastatic breast cancer demonstrated higher response rates, longer time to progression and an improved toxicity profile for nabP compared with standard paclitaxel. The U.S. Food and Drug Administration approved nabP in late 2004 for treatment of metastatic breast cancer after failure of an anthracycline-based regimen. PMID:17028669

Pinder, Mary C; Ibrahim, Nuhad K

2006-09-01

343

A phase I and pharmacokinetic study of bi-daily dosing of oral paclitaxel in combination with cyclosporin A  

Microsoft Academic Search

Purpose: To investigate dose escalation of bi-daily (b.i.d.) oral paclitaxel in combination with cyclosporin A in order to improve and prolong the systemic exposure to paclitaxel and to explore the maximum tolerated dose and dose limiting toxicity (DLT) of this combination. Patients and methods: A total of 15 patients received during course 1 two doses of oral paclitaxel (2Ꮔ, 2Ꮲ,

Mirte M. Malingré; Jos H. Beijnen; Hilde Rosing; Franciska J. Koopman; Olaf van Tellingen; Ken Duchin; Wim W. Ten Bokkel Huinink; Martha Swart; Jan Lieverst; Jan H. M. Schellens

2001-01-01

344

Resistance mechanisms determining the in vitro sensitivity to paclitaxel of tumour cells cultured from patients with ovarian cancer  

Microsoft Academic Search

Paclitaxel, a drug which stabilises microtubules, demonstrates marked activity against ovarian cancer. We investigated the sensitivity to paclitaxel of tumour cells from disaggregated solid tumours or tumour-bearing ascites from 7 ovarian cancer patients, and 21 established tumour cell lines (ovarian, melanoma and lung). Response was quantitated by [3H]-thymidine incorporation in 96-well plates or by colony growth. Dose-response curves to paclitaxel

B. C. Baguley; E. S. Marshall; J. R. Whittaker; M. C. Dotchin; J. Nixon; M. R. McCrystal; G. J. Finlay; J. H. L. Matthews; K. M. Holdaway; P. van Zijl

1995-01-01

345

SPARC Expression Correlates with Tumor Response to Albumin-Bound Paclitaxel in Head and Neck Cancer Patients  

Microsoft Academic Search

SPARC up-regulation is a poor prognostic factor in head and neck cancer. It was hypothesized that because of a SPARC-albumin interaction, tumoral SPARC facilitates the accumulation of albumin in the tumor and increases the effectiveness of albumin-bound paclitaxel (nab-paclitaxel). This hypothesis was tested by correlating the re- sponse to nab-paclitaxel and SPARC tumor expression in a retrospective analysis of a

Neil Desai; Vuong Trieu; Bruno Damascelli; Patrick Soon-Shiong

346

Phase I feasibility study of intraperitoneal cisplatin and intravenous paclitaxel followed by intraperitoneal paclitaxel in untreated ovarian, fallopian tube, and primary peritoneal carcinoma: A Gynecologic Oncology Group Study  

PubMed Central

Purpose Intraperitoneal chemotherapy has shown a survival advantage over intravenous chemotherapy for women with newly diagnosed optimally debulked epithelial ovarian, fallopian tube, or primary peritoneal carcinoma. However, significant toxicity has limited its acceptance. In an effort to reduce toxicity, the Gynecologic Oncology Group conducted a Phase I study to evaluate the feasibility of day 1 intravenous (IV) paclitaxel and intraperitoneal (IP) cisplatin followed by day 8 IP paclitaxel on an every 21-day cycle. Methods Patients with Stage IIB-IV epithelial ovarian, fallopian tube, primary peritoneal carcinomas or carcinosarcoma received paclitaxel 135 mg/m2 IV over 3 hours followed by cisplatin 75 mg/m2 IP on day 1 and paclitaxel 60 mg/m2 IP on day 8 of a 21 day cycle with 6 cycles planned. Dose-limiting toxicity (DLT) was defined as febrile neutropenia or dose-delay of greater than 2 weeks due to failure to recover counts, or Grade 3-5 non-hematologic toxicity occurring within the first 4 cycles of treatment. Results Twenty of 23 patients enrolled were evaluable and nineteen (95%) completed all six cycles of therapy. Three patients experienced a DLT consisting of infection with normal absolute neutrophil count, grade 3 hyperglycemia, and grade 4 abdominal pain. Conclusions This modified IP regimen which administers both IV paclitaxel and IP cisplatin on day one, followed by IP paclitaxel on day eight, of a twenty-one day cycle appears feasible and is an attractive alternative to the intraperitoneal treatment regimen administered in GOG-0172.

Dizon, Don S.; Sill, Michael W.; Gould, Natalie; Rubin, Stephen C.; Yamada, S. Diane; DeBernardo, Robert L.; Mannel, Robert S.; Eisenhauer, Eric L.; Duska, Linda R.; Fracasso, Paula M.

2011-01-01

347

Combined modality radioimmunotherapy: synergistic effect of Paclitaxel and additive effect of Bevacizumab  

PubMed Central

Introduction This study was undertaken to investigate the effect of Paclitaxel and Bevacizumab on the therapeutic efficacy of 90Y-labeled B3 mAb, directed against Ley antigen, for the treatment of Ley-positive A431 tumors implanted s.c. in the right hind flank of nude mice. Methods When the tumor size reached ~200 mm3, the mice received a single dose of i.v. 90Y-labeled B3 (60 ?Ci/150 ?g or 100 ?Ci/150 ?g B3), i.p. Paclitaxel (40 mg/kg), or i.v. Bevacizumab (5 mg/kg) for monotherapy. To investigate the effect of combined therapies on survival, the mice were treated with two or three agents in the following combinations: 90Y-B3 on day 0 and Paclitaxel on day 1; Bevacizumab on ?1 day and 90Y-B3 on day 0; Bevacizumab on ?1 day and Paclitaxel on day 1; Bevacizumab, 90Y-B3, and Paclitaxel each at 1-day intervals. The mice with no treatment were used as a control. The tumor volume at 1,000 mm3 was used as a surrogate endpoint of survival. Results Compared to control animals, Paclitaxel delayed tumor growth with a significantly longer median survival time (P < 0.001) whereas Bevacizumab alone showed a less pronounced effect on a median survival time (P = 0.18). 90Y-B3 increased the median survival time in a dose dependent manner (P < 0.05). The combined therapy of Bevacizumab with Paclitaxel produced a trend toward an increase of the median survival time compared to Paclitaxel alone (P = 0.06), whereas Bevacizumab combined with 90Y-B3 showed a statistically insignificant increase in the median survival time compared to 90Y-B3 alone (P = 0.25). The tumor sizes of all animals in these groups reached the surrogate end point of survival by day 35. In contrast, the combined therapy involving 90Y-B3 with Paclitaxel showed a striking synergistic effect in shrinking tumors and prolonging the survival time (P < 0.001); on day 120, 3 of 9 mice (33%) and 6 of 6 mice (100%) were alive without tumor when treated with 60 ?Ci 90Y-B3 and 100 ?Ci 90Y-B3, respectively. The addition of Bevacizumab treatment one day before the combined therapy of 60 ?Ci 90Y-B3 with Paclitaxel did not produce a statistically significant increase in survival when compared to the 90Y-B3 with Paclitaxel (P > 0.10). Fluorescence microscopy analysis indicated that Paclitaxel increased, whereas Bevacizumab decreased the accumulation and penetration of Alexa Fluor 647-B3 into tumor microenvironment compared to the control (P < 0.05). Conclusion Our findings on the Paclitaxel effect support a hypothesis that the increased tumor accumulation and penetration of 90Y-B3 as well as the high radio-sensitization of tumor cells by Paclitaxel may be the major factors responsible for the synergistic effect of the combined therapy involving 90Y-B3 with Paclitaxel.

Jang, B. S.; Lee, S. -M.; Kim, H. S.; Shin, I. S.; Razjouyan, F.; Wang, S.; Yao, Z.; Pastan, I.; Dreher, M. R.; Paik, C. H.

2011-01-01

348

Is a reduction in radiation lung volume and dose necessary with paclitaxel chemotherapy for node-positive breast cancer?  

SciTech Connect

Purpose: To evaluate and quantify the effect of irradiated lung volume, radiation dose, and paclitaxel chemotherapy on the development of radiation pneumonitis (RP) in breast cancer patients with positive lymph nodes. Methods and Materials: We previously reported the incidence of RP among 41 patients with breast cancer treated with radiotherapy (RT) and adjuvant paclitaxel-containing chemotherapy. We recorded the central lung distance, a measure of the extent of lung included in the RT volume, in these patients. We used this measure and the historical and observed rates of RP in our series to model the lung tolerance to RT in patients receiving chemotherapy (CHT) both with and without paclitaxel. To evaluate the risk factors for the development of RP, we performed a case-control study comparing paclitaxel-treated patients who developed RP with those who did not, and a second case-control study comparing patients receiving paclitaxel in addition to standard CHT/RT (n = 41) and controls receiving standard CHT/RT alone (n 192). Results: The actuarial rate of RP in the paclitaxel-treated group was 15.4% compared with 0.9% among breast cancer patients treated with RT and non-paclitaxel-containing CHT. Our mathematical model found that the effective lung tolerance for patients treated with paclitaxel was reduced by approximately 24%. No statistically significant difference was found with regard to the dose delivered to specific radiation fields, dose per fraction, central lung distance, or percentage of lung irradiated in the case-control study of paclitaxel-treated patients who developed RP compared with those who did not. In the comparison of 41 patients receiving RT and CHT with paclitaxel and 192 matched controls receiving RT and CHT without paclitaxel, the only significant differences identified were the more frequent use of a supraclavicular radiation field and a decrease in the RT lung dose among the paclitaxel-treated patients. This finding indicates that the major factor associated with development of RP was paclitaxel treatment. Conclusions: The use of paclitaxel chemotherapy and RT in the primary treatment of node-positive breast cancer is likely to increase the incidence of RP. In patients treated with paclitaxel, reducing the percentage of lung irradiated by 24% should reduce the risk of RP to 1%, according to our calculations of lung tolerance. Future clinical trials using combination CHT that includes paclitaxel and RT should carefully evaluate the incidence and severity of RP and should also accurately monitor the extent of lung included within the RT volume to develop safe guidelines for the delivery of what is becoming standard therapy for node-positive breast cancer.

Taghian, Alphonse G. [Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA (United States)]. E-mail: ataghian@partners.org; Assaad, Sherif I. [Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA (United States); Niemierko, Andrzej [Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA (United States); Floyd, Scott R. [Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA (United States); Powell, Simon N. [Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA (United States)

2005-06-01

349

Low-dose paclitaxel modulates tumour fibrosis in gastric cancer  

PubMed Central

Various treatments have been used for peritoneal dissemination, which is the most common mode of metastasis in gastric cancer, but sufficiently good clinical outcomes have not yet been obtained because of the presence of rich fibrous components and acquired drug resistance. Epithelialmesenchymal transition (EMT) is one of the major causes of tissue fibrosis and transforming growth factor-? (TGF-?) has a pivotal function in the progression of EMT. Smad proteins play an important role in the TGF-? signalling pathway. The TGF-?/Smad signalling pathway can be modulated by stabilising microtubules with paclitaxel (PTX). Here, we investigated whether paclitaxel can modulate TGF-?/Smad signalling in human peritoneal methothelial cells (HPMCs). To determine the cytostatic concentrations of antineoplastic agents in HPMCs, a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was performed using PTX, 5-fluorouracil and cisplatin. The minimum concentration that caused significant inhibition of TGF-?1-induced morphological changes in human peritoneal methothelial cells on pre-treatment with PTX was 5 nM at 48 h (cell viability: 87.1±1.5%, P<0.01). The TGF-? signalling cascade and the status of various fibrous components were evaluated by immunofluorescence staining, real-time quantitative PCR and western blotting. TGF-? signalling induced morphological changes, ?-SMA expression and collagen I synthesis in HPMCs and PTX treatment suppressed these EMT-like changes. Moreover, PTX treatment markedly suppressed Smad2 phosphorylation. These data suggest that at a low-dose, PTX can significantly suppress the TGF-?/Smad signalling pathway by inhibiting Smad2 phosphorylation in the human peritoneum and that this can reduce stromal fibrosis.

TSUKADA, TOMOYA; FUSHIDA, SACHIO; HARADA, SHINICHI; TERAI, SHIROH; YAGI, YASUMICHI; KINOSHITA, JUN; OYAMA, KATSUNOBU; TAJIMA, HIDEHIRO; NINOMIYA, ITASU; FUJIMURA, TAKASHI; OHTA, TETSUO

2013-01-01

350

Polymer-polymer conjugation to fabricate multi-block polymer as novel drug carriers: poly(lactic acid)-poly(ethylene glycol)-poly(L-lysine) to enhance paclitaxel target delivery.  

PubMed

Multifunctional nanoparticles assembled from multi-block polymers are now one of the most convenient and convincing carriers for target drug delivery. Multi-block polymers could provide multi-functions such as sufficient drug loading capability and efficient target ligand coupling potency. In this article, novel multi-block polymer poly(lactic acid)-poly(ethylene glycol)-poly(L-lysine) (PLA-PEG-PLL) with relatively precise block molecular weight were synthesized by new method which we called polymer-polymer conjugation. This method conjugated different polymer blocks by reactions between the terminal active groups of different blocks, thus simplified the synthesis procedure. The obtained PLA-PEG-PLL was characterized by 1H NMR and gel permeation chromatography. The controlled drug delivery capability and the target ligand coupling potency of PLA-PEG-PLL were verified using paclitaxel (PTX) as model drug and vascular endothelial growth factor (VEGF) antibody as target ligand. The PTX-loaded PLA-PEG-PLL nanoparticles (PNP) and VEGF antibody modified PTX-loaded PLA-PEG-PLL nanoparticles (VPNP) were prepared using solvent diffusion methods. The two nanoparticles showed spherical or ellipsoidal shapes with uniform particle size distribution (190.1 +/- 1.27 nm and 203.6 +/- 4.10 nm for PNP and VPNP, respectively) and positive zeta potential (23.76 +/- 0.72 mv and 20.76 +/- 0.34 mv for PNP and VPNP, respectively). The cellular cytotoxicity, cellular uptake, in vivo therapeutic effects of the two nanoparticles were investigated. Cytotoxicity of VPNP against HepG2 cells was superior to that of PNP and Taxol. The VPNP and PNP showed better antitumor efficacy in a murine model bearing H22 compared with Taxol and VPNP was the best. The study on cellular uptake indicated that the better antitumor efficacy of VPNP was attributed to the increased uptake of drug by tumor cells. These results demonstrated that PLA-PEG-PLL was a favorable multifunctional material for drug target delivery and polymer-polymer conjugation was a promising method to fabricate novel multi-block polymers. PMID:24749390

Liu, Yongjun; Liu, Chunxi; Li, Min; Liu, Fengxi; Feng, Lixia; Zhang, Li; Zhang, Na

2014-06-01

351

Novel core-shell magnetic nanoparticles for Taxol encapsulation in biodegradable and biocompatible block copolymers: preparation, characterization and release properties.  

PubMed

Theranostic polymeric nanocarriers loaded with anticancer drug Taxol and superparamagnetic iron oxide nanocrystals have been developed for possible magnetic resonance imaging (MRI) use and cancer therapy. Multifunctional nanocarriers with a core-shell structure have been prepared by coating superparamagnetic Fe3O4 nanoparticles with block copolymer of poly(ethylene glycol)-b-poly(propylene succinate) with variable molecular weights of the hydrophobic block poly(prolylene succinate). The multifunctional polymer nano-vehicles were prepared using a nanoprecipitation method. Scanning transmission electron microscopy revealed the encapsulation of magnetic nanoparticles inside the polymeric matrix. Energy dispersive X-ray spectroscopy and electron energy loss spectroscopy mapping allowed us to determine the presence of the different material ingredients in a quantitative way. The diameter of the nanoparticles is below 250 nm yielding satisfactory encapsulation efficiency. The nanoparticles exhibit a biphasic drug release pattern in vitro over 15 days depending on the molecular weight of the hydrophobic part of the polymer matrix. These new systems where anti-cancer therapeutics like Taxol and iron oxide nanoparticles (IOs) are co-encapsulated into new facile polymeric nanoparticles, could be addressed as potential multifunctional vehicles for simultaneous drug delivery and targeting imaging as well as real time monitoring of therapeutic effects. PMID:23524084

Filippousi, Maria; Papadimitriou, Sofia A; Bikiaris, Dimitrios N; Pavlidou, Eleni; Angelakeris, Mavroeidis; Zamboulis, Dimitris; Tian, He; Van Tendeloo, Gustaaf

2013-05-01

352

Loss of functional E-cadherin renders cells more resistant to the apoptotic agent taxol in vitro  

SciTech Connect

Experimental evidence supports a role for E-cadherin in suppressing invasion, metastasis, and proliferation. Germline mutations of the E-cadherin represent the genetic cause of hereditary diffuse gastric cancer (HDGC). In this type of tumor, isolated cancer cells permeate the basal membrane and paradoxically survive in the gastric wall in the absence of contact with neighbor epithelial cells or with the extracellular matrix. This suggests that upon E-cadherin deregulation, cells acquired resistance to apoptosis. To test this hypothesis, CHO cells stably expressing either wild-type E-cadherin or the HDGC-related germline mutations T340A and V832M were seeded either on a thin layer of collagen type I or on plastic and then subjected to the apoptotic agent taxol. We found that in vitro functional E-cadherin renders cells more sensitive to the effect of taxol. Our results also indicate that this effect is associated to decreased level of the anti-apoptotic bcl-2 protein.

Ferreira, Paulo [Instituto de Patologia e Imunologia Molecular da Universidade do Porto (IPATIMUP), 4200 Porto (Portugal); Oliveira, Maria Jose [Instituto de Patologia e Imunologia Molecular da Universidade do Porto (IPATIMUP), 4200 Porto (Portugal); Beraldi, Eliana [Prostate Centre, Vancouver General Hospital, Vancouver, BC (Canada); Mateus, Ana Rita [Instituto de Patologia e Imunologia Molecular da Universidade do Porto (IPATIMUP), 4200 Porto (Portugal); Nakajima, Takashi [Department of Tumor Pathology, Gunma University Graduate School of Medicine, Gunma (Japan); Gleave, Martin [Prostate Centre, Vancouver General Hospital, Vancouver, BC (Canada); Yokota, Jun [Biology Division, National Cancer Center Research Institute, Tokyo (Japan); Carneiro, Fatima [Instituto de Patologia e Imunologia Molecular da Universidade do Porto (IPATIMUP), 4200 Porto (Portugal); Faculdade de Medicina, Hospital S. Joao, Porto (Portugal); Huntsman, David [Genetic Pathology Evaluation Centre of the Department of Pathology and Prostate Centre at Vancouver General Hospital, Department of Pathology, British Columbia Cancer Agency and University of British Columbia, Vancouver (Canada); Seruca, Raquel [Instituto de Patologia e Imunologia Molecular da Universidade do Porto (IPATIMUP), 4200 Porto (Portugal); Faculdade de Medicina, Hospital S. Joao, Porto (Portugal); Suriano, Gianpaolo [Instituto de Patologia e Imunologia Molecular da Universidade do Porto (IPATIMUP), 4200 Porto (Portugal) and Genetic Pathology Evaluation Centre of the Department of Pathology and Prostate Centre at Vancouver General Hospital, Department of Pathology, British Columbia Cancer Agency and University of British Columbia, Vancouver (Canada)]. E-mail: gsuriano@ipatimup.pt

2005-10-15

353

Cremophor-Induced Lupus Erythematosus-Like Reaction with Taxol Administration: A Case Report and Review of the Literature  

Microsoft Academic Search

We report the first case of Cremophor EL-induced cutaneous lupus erythematosus-like reaction in a 40-year-old female undergoing treatment for breast cancer. There have been four reported cases of paclitaxel- and four cases of docetaxel-induced cutaneous lupus reactions in the published literature [Dasanu and Alexandrescu: South Med J 2008;101:1161–1162; Adachi and Horikawa: J Dermatol 2007;34:473–476; Lortholary et al: Presse Med 2007;36:1207–1208;

Anthony Q. Pham; David Berz; Patricia Karwan; Gerald A. Colvin

2011-01-01

354

Rapamycin potentiates the effects of paclitaxel in endometrial cancer cells through inhibition of cell proliferation and induction of apoptosis1  

PubMed Central

mTOR inhibitors modulate signaling pathways involved in cell cycle progression, and recent phase II trials demonstrate activity in endometrial cancer patients. Our objective was to examine the effects of combination therapy with rapamycin and paclitaxel in endometrial cancer cell lines. Paclitaxel inhibited proliferation in a dose-dependent manner in both cell lines with IC50 values of 0.1–0.5 nM and 1–5 nM for Ishikawa and ECC-1 cells, respectively. To assess synergy of paclitaxel and rapamycin, the combination index (CI) was calculated by the method of Chou and Talalay. Simultaneous exposure of cells to various doses of paclitaxel in combination with rapamycin (1 nM) resulted in a significant synergistic anti-proliferative effect (CI <1, range 0.131–0.920). Rapamycin alone did not induce apoptosis, but combined treatment with paclitaxel increased apoptosis over that of paclitaxel alone. Treatment with rapamycin and paclitaxel resulted in decreased phosphorylation of S6 and 4E-BP1, two critical downstream targets of the mTOR pathway. Rapamycin decreased hTERT mRNA expression by real-time RT-PCR while paclitaxel alone had no effect on telomerase activity. Paclitaxel increased polymerization and acetylation of tubulin, and rapamycin appeared to enhance this effect. Thus, in conclusion, we demonstrate that rapamycin potentiates the effects of paclitaxel in endometrial cancer cells through inhibition of cell proliferation, induction of apoptosis and potentially increased polymerization and acetylation of tubulin. This suggests that the combination of rapamycin and paclitaxel may be a promising effective targeted therapy for endometrial cancer.

Shafer, Aaron; Zhou, Chunxiao; Gehrig, Paola A.; Boggess, John F.; Bae-Jump, Victoria L.

2009-01-01

355

Development of lipid-based nanoparticles for enhancing the oral bioavailability of paclitaxel.  

PubMed

The current research work investigates the potential of solid lipid nanoparticles (SLNs) in improving the oral bioavailability of paclitaxel. Paclitaxel-loaded SLNs (PTX-SLNs) were prepared by modified solvent injection method using stearylamine as lipid, soya lecithin and poloxamer 188 as emulsifiers. SLNs were characterized in terms of surface morphology, size and size distribution, surface chemistry and encapsulation efficiency. Pharmacokinetics and bioavailability studies were conducted in male Swiss albino mice after oral administration of PTX-SLNs. SLNs exhibited spherical shape with smooth surface as analyzed by transmission electron microscopy (TEM). The mean particle size of SLNs was 96 ± 4.4 nm with a low polydispersity index of 0.162 ± 0.04 and zeta potential of 39.1 ± 0.8 mV. The drug entrapment efficiency was found to be 75.42 ± 1.5% with a loading capacity of 31.5 ± 2.1% (w/w). Paclitaxel showed a slow and sustained in vitro release profile and followed Higuchi kinetic equations. After oral administration of the PTX-SLNs, drug exposure in plasma and tissues was ten- and twofold higher, respectively, when compared with free paclitaxel solution. PTX-SLNs produced a high mean C (max) (10,274 ng/ml) compared with that of free paclitaxel solution (3,087 ng/ml). The absorbed drug was found to be distributed in liver, lungs, kidneys, spleen, and brain. The results suggested that PTX-SLNs dispersed in an aqueous environment are promising novel formulations that enhanced the oral bioavailability of hydrophobic drugs, like paclitaxel and were quite safe for oral delivery of paclitaxel as observed by in vivo toxicity studies. PMID:21637945

Pandita, Deepti; Ahuja, Alka; Lather, Viney; Benjamin, Biju; Dutta, Tathagata; Velpandian, Thirumurthy; Khar, Roop Krishen

2011-06-01

356

A Phase I study of paclitaxel and continuous daily CAI in patients with refractory solid tumors  

PubMed Central

Background Carboxyamido-triazole (CAI) is a calcium influx inhibitor with anti-angiogenic and anti-invasive properties and stabilizes tumor progression in patients. We hypothesized daily oral micronized CAI with q3 week paclitaxel would be well-tolerated and active. Results Twenty-nine heavily pretreated patients [median 3 (0–7)] were enrolled on five dose levels. No additive or cumulative toxicity was observed, and grade III nonhematological toxicity was rare. Neutropenia was the most common hematologic toxicity, seen in 79% of patients, with a trend towards increasing grade with higher paclitaxel doses. The recommended phase II dose defined by the maximum tolerated dose (MTD) was CAI 250 mg daily and paclitaxel 200 mg/m2 q3weeks. Pharmacokinetic analysis revealed paclitaxel increases CAI trough concentration at all dose levels by over 100% (p < 0.0001). A trend towards higher steady-state CAI trough concentrations was found in patients with a partial response (PR; p = 0.09). Six patients had confirmed PR (24%; 4–67 cycles, median 10); two patients had minor responses. Patients and methods Eligible patients with solid tumors received micronized CAI daily (150–250 mg PO) and paclitaxel intravenously q3weeks (175–250 mg/m2), sequentially escalating each drug. CAI preceded paclitaxel by one week to permit pharmacokinetic analysis. Patients were assessed for toxicity, pharmacokinetics and disease outcome. Conclusions The MTD of the combination of CAI and paclitaxel is 250 mg daily and 200 mg/m2 q3weeks, respectively. The combination is tolerable and has potential antitumor activity.

Azad, Nilofer; Perroy, Alyssa; Gardner, Erin; Imamura, Chiyo K.; Graves, Cynthia; Sarosy, Gisele A.; Minasian, Lori; Kotz, Herbert; Raggio, Miranda; Figg, William D.; Kohn, Elise C.

2011-01-01

357

Improvement of paclitaxel therapeutic index by derivatization and association to a cholesterol-rich microemulsion: in vitro and in vivo studies  

Microsoft Academic Search

A cholesterol-rich microemulsion or nanoparticle termed LDE concentrates in cancer tissues after injection into the bloodstream. Here the cytotoxicity, pharmacokinetics, toxicity to animals and therapeutic action of a paclitaxel lipophilic derivative associated to LDE is compared with those of the commercial paclitaxel. Results show that LDE-paclitaxel oleate is stable. The cytostatic activity of the drug in the complex is diminished

Debora G. Rodrigues; Durvanei A. Maria; Denise C. Fernandes; Claudete J. Valduga; Ricardo D. Couto; Olga C. M. Ibañez; Raul C. Maranhão

2005-01-01

358

Schedule-dependent paclitaxel tolerance/activity: data from a 7 day infusion phase I study with pharmacokinetics in paclitaxel refractory ovarian cancer.  

PubMed

Our objective was to determine the maximum tolerated dose (MTD) of paclitaxel when given as a 7 day continuous i.v. infusion, repeated every 3 weeks, and to evaluate the toxicity and the efficacy of such a schedule of administration as a salvage treatment in ovarian cancer patients pretreated and refractory to 3 or 24 h paclitaxel. Thirteen women were enrolled in this phase I trial. Four dose levels ranging from 105 to 157.5 mg/m2/cycle were explored. Two of four patients experienced dose-limiting febrile neutropenia at the dose of 157.5 mg/m2. No objective response was observed, although three patients experienced disease stabilization (five to six cycles), with regression of disease symptoms, two of them having sustained 50% or greater decrease in CA 125. We conclude that the MTD in this population was paclitaxel 140 mg/m2/7 days. Schedule-dependent mechanisms of resistance to paclitaxel could not be demonstrated in this clinical setting of heavily pretreated ovarian cancer patients. PMID:9396620

Soulié, P; Trandafir, L; Taamma, A; Lokiec, F; Brain, E; Delord, J P; Mita, A; Vannetzel, J M; Cvitkovic, E; Misset, J L

1997-09-01

359

Phase I study of temozolomide plus paclitaxel in patients with advanced malignant melanoma and associated in vitro investigations.  

PubMed

The purpose of this study was to determine activity of temozolomide combined with paclitaxel or epothilone B in vitro, and to investigate the combination of temozolomide with paclitaxel in a Phase I clinical trial. Melanoma cell lines A375P and DX3 were treated with temozolomide and either paclitaxel or epothilone B. Combination indices were determined to assess the degree of synergism. In a clinical study, 21 patients with malignant melanoma were treated with increasing doses of temozolomide (orally, days 1-5), in combination with a fixed dose of paclitaxel (i.v. infusion day 1), followed by dose escalation of the latter drug. Cycles of treatment were repeated every 3 weeks. Pharmacokinetics of both agents were determined on day 1, with temozolomide pharmacokinetics also assessed on day 5. All three compounds were active against the melanoma cell lines, with epothilone B being the most potent. There was a strong degree of synergism between temozolomide and either paclitaxel or epothilone B. In the clinical study, no pharmacokinetic interaction was observed between temozolomide and paclitaxel. Dose escalation of both drugs to clinically active doses was possible, with no dose-limiting toxicities observed at 200 mg m(-2) day(-1) temozolomide and 225 mg m(-2) day(-1) paclitaxel. There were two partial responses out of 15 evaluable patients. One patient remains alive and symptom-free at 4 years after treatment. Temozolomide and paclitaxel may be administered safely at clinically effective doses. Further evaluation of these combinations in melanoma is warranted. PMID:15756276

Azzabi, A; Hughes, A N; Calvert, P M; Plummer, E R; Todd, R; Griffin, M J; Lind, M J; Maraveyas, A; Kelly, C; Fishwick, K; Calvert, A H; Boddy, A V

2005-03-28

360

Phase I study of temozolomide plus paclitaxel in patients with advanced malignant melanoma and associated in vitro investigations  

PubMed Central

The purpose of this study was to determine activity of temozolomide combined with paclitaxel or epothilone B in vitro, and to investigate the combination of temozolomide with paclitaxel in a Phase I clinical trial. Melanoma cell lines A375P and DX3 were treated with temozolomide and either paclitaxel or epothilone B. Combination indices were determined to assess the degree of synergism. In a clinical study, 21 patients with malignant melanoma were treated with increasing doses of temozolomide (orally, days 1–5), in combination with a fixed dose of paclitaxel (i.v. infusion day 1), followed by dose escalation of the latter drug. Cycles of treatment were repeated every 3 weeks. Pharmacokinetics of both agents were determined on day 1, with temozolomide pharmacokinetics also assessed on day 5. All three compounds were active against the melanoma cell lines, with epothilone B being the most potent. There was a strong degree of synergism between temozolomide and either paclitaxel or epothilone B. In the clinical study, no pharmacokinetic interaction was observed between temozolomide and paclitaxel. Dose escalation of both drugs to clinically active doses was possible, with no dose-limiting toxicities observed at 200?mg?m?2?day?1 temozolomide and 225?mg?m?2?day?1 paclitaxel. There were two partial responses out of 15 evaluable patients. One patient remains alive and symptom-free at 4 years after treatment. Temozolomide and paclitaxel may be administered safely at clinically effective doses. Further evaluation of these combinations in melanoma is warranted.

Azzabi, A; Hughes, A N; Calvert, P M; Plummer, E R; Todd, R; Griffin, M J; Lind, M J; Maraveyas, A; Kelly, C; Fishwick, K; Calvert, A H; Boddy, A V

2005-01-01

361

Synergistic Suppression of Microtubule Dynamics by Discodermolide and Paclitaxel in Non-Small Cell Lung Carcinoma Cells  

Microsoft Academic Search

Discodermolide is a new microtubule-targeted antimitotic drug in Phase I clinical trials that, like paclitaxel, stabilizes microtubule dynamics and enhances microtubule polymer mass in vitro and in cells. Despite their apparently similar binding sites on microtubules, discodermolide acts synergistically with paclitaxel to inhibit proliferation of A549 human lung cancer cells (L. Martello et al., Clin. Cancer Res., 6: 1978 -1987,

Stephane Honore; Kathy Kamath; Diane Braguer; Susan Band Horwitz; Leslie Wilson; Claudette Briand; Mary Ann Jordan

2004-01-01

362

Phase I study of saracatinib (AZD0530) in combination with paclitaxel and/or carboplatin in patients with solid tumours  

PubMed Central

Background: As a prelude to combination studies aimed at resistance reversal, this dose-escalation/dose-expansion study investigated the selective Src kinase inhibitor saracatinib (AZD0530) in combination with carboplatin and/or paclitaxel. Methods: Patients with advanced solid tumours received saracatinib once-daily oral tablets in combination with either carboplatin AUC 5 every 3 weeks (q3w), paclitaxel 175?mg?m?2 q3w, paclitaxel 80?mg?m?2 every 1 week (q1w), or carboplatin AUC 5 plus paclitaxel 175?mg?m?2 q3w. The primary endpoint was safety/tolerability. Results: A total of 116 patients received saracatinib 125 (N=20), 175 (N=44), 225 (N=40), 250 (N=9), or 300?mg (N=3). There were no clear dose-related trends within each chemotherapy regimen group in number or severity of adverse events (AEs). However, combining all groups, the occurrence of grade ?3 asthenic AEs (all causality) was dose-related (125?mg, 10% 175?mg, 20% ?225?mg, 33%), and grade ?3 neutropenia occurred more commonly at doses ?225?mg. There was no evidence that saracatinib affected exposure to carboplatin or paclitaxel, or vice versa. Objective responses were seen in 5 out of 44 patients (11%) receiving carboplatin plus paclitaxel q3w, and 5 out of 24 (21%) receiving paclitaxel q1w. Conclusion: Saracatinib doses up to 175?mg with paclitaxel with/without carboplatin showed acceptable toxicity in most patients, and are suitable for further trials.

Kaye, S; Aamdal, S; Jones, R; Freyer, G; Pujade-Lauraine, E; de Vries, E G E; Barriuso, J; Sandhu, S; Tan, D S-W; Hartog, V; Kuenen, B; Ruijter, R; Kristensen, G B; Nyakas, M; Barrett, S; Burke, W; Pietersma, D; Stuart, M; Emeribe, U; Boven, E

2012-01-01

363

Effects of paclitaxel, docetaxel and their combinations on subcutaneous lymphomas in inbred Sprague-Dawley/Cub rats.  

PubMed

We investigated, whether the effects on paclitaxel, docetaxel or their combinations on T-cell lymphomas in Sprague-Dawley/Cub rats were mainly caused by their different efficiency or combination of different mechanism of action, or limited by metabolic inactivation by P450 enzymes or drug efflux caused by P-glycoprotein (P-gp). Docetaxel most effectively prolonged the survival of rats and the time of lymphoma appearance, inhibited their intravital size and weight after sacrifice. Paclitaxel was poorly effective and combined administration had intermediate effects. Blood levels of both drugs were similar. Repeated administration of paclitaxel, but not docetaxel, decreased its area under concentration, but the effect disappeared 6h after dosing and was not sufficient to explain lower effects of paclitaxel. The faster metabolism of docetaxel than paclitaxel in vitro did not limit its higher efficiency and repeated administration of paclitaxel did not induce its metabolism to decrease its blood levels sufficiently. Likewise, undetectable expression of P-gp protein in tumours could not explain lower effects of paclitaxel, which is a better substrate of P-gp. Docetaxel was three-fold more effective than paclitaxel against P388D1 lymphoma cell line, used as a model of the T-cell lymphoma and combined action was dominated by the effects of docetaxel. Thus, docetaxel was effective against T-cell lymphomas and may be a potential anticancer drug in similar indications. PMID:17000091

Otová, Berta; Václavíková, Radka; Danielová, Vlasta; Holubová, Jaroslava; Ehrlichová, Marie; Horský, Stanislav; Soucek, Pavel; Simek, Petr; Gut, Ivan

2006-12-01

364

Alteration of the Mitochondrial Apoptotic Pathway Is Key to Acquired Paclitaxel Resistance and Can Be Reversed by ABT-737  

Microsoft Academic Search

Paclitaxel is a microtubule-targeting antineoplastic drug widely used in human cancers. Even when tumors are initially responsive, progression of disease despite continued taxane therapy is all too common in the treatment of many of the most common epithelial cancers, including breast cancer. However, the mechanisms underlying paclitaxel resistance in cancer cells are not completely understood. Our hypothesis is that changes

Ozgur Kutuk; Anthony Letai

2008-01-01

365

Efficacy of poly(sebacic acid-co-ricinoleic acid) biodegradable delivery system for intratumoral delivery of paclitaxel.  

PubMed

The effectiveness of an injectable polymeric formulation, based on poly(sebacic acid-co-ricinoleic acid) and paclitaxel against a heterotopic tumor model was studied. An injectable pasty polymer that releases an incorporated drug over a period of weeks was used. The degradation rate of formulations with paclitaxel was examined in vitro and in vivo. The effectiveness of the polymeric carrier of paclitaxel was investigated using a melanoma heterotopic model in C57BL/6 mice. Tumor bearing animals were injected intratumorally with 0.1 ml of formulations containing 5%, 10%, 15%, and 20% paclitaxel. Formulations with 5% and 10% paclitaxel content degraded faster in vivo then in vitro. Changes in tumor progression, survival time, and body weight were observed over a period of 77 days. The highest tumor size was reported for the control groups that did not receive paclitaxel in their treatment regiment: 3.6 g on day 20, while in all groups treated with polymer loaded with paclitaxel the tumor size was much smaller than that in the blank polymer or non treatment groups and ranged from 1.3 g to 0.3 g. Intratumoral injection of paclitaxel loaded in the polymer was found to be an effective treatment for localized tumors. PMID:19343769

Shikanov, Ariella; Vaisman, Boris; Shikanov, Sergey; Domb, Abraham J

2010-03-15

366

Pharmacological study of paclitaxel duration of infusion combined with GFR-based carboplatin in the treatment of ovarian cancer  

Microsoft Academic Search

Purpose: To determine the effect on systemic pharmacology and clinical toxicity of dose and mode of administration of paclitaxel combined with carboplatin in the treatment of ovarian cancer. Patients and methods: A total of 18 patients were treated with a dose of carboplatin determined by GFR, to attain a target AUC of 6 or 7 mg\\/ml·min. The paclitaxel dose was

Alan V. Boddy; Melanie J. Griffin; Julieann Sludden; Huw D. Thomas; Kevin Fishwick; James G. Wright; Ruth E. Plummer; Martin Highley; Hilary A. Calvert

2001-01-01

367

Pharmacokinetic and efficacy study of cisplatin and paclitaxel formulated in a new injectable poly(sebacic-co-ricinoleic acid) polymer.  

PubMed

Injectable biodegradable polymer poly(sebacic-co-ricinoleic acid), P(SA-RA) is currently under development for intratumoral (IT) delivery of drugs for treating solid tumors. This study presents formulation development, pharmacokinetic and efficacy studies of two anticancer drugs (cisplatin and paclitaxel) formulated with P(SA-RA) polymer. In pharmacokinetic study, systemic exposure and pharmacokinetic parameters of cisplatin/paclitaxel following single intravenous (IV) or subcutaneous (SC) doses of cisplatin/paclitaxel was compared with intramuscular (IM) or SC doses of cisplatin/paclitaxel formulated with P(SA-RA) polymer in male CD rat. Simultaneously, the tumor reduction effect and toxicity for these formulations were evaluated in human FaDu head and neck tumor xenograft subcutaneous nude mouse model. Pharmacokinetic data reflect the lower maximal concentrations and sustained release of polymer-cisplatin/paclitaxel formulations compared to standard cisplatin/paclitaxel administration. Regarding efficacy study, a single IT or near the tumor injection (NT) of polymer-paclitaxel or polymer-cisplatin formulation significantly reduced the tumor size, compared to the standard paclitaxel or cisplatin treatments. No death or toxicity and no effect on body weight as well as macroscopic and/or microscopic changes in or near the injected area were observed, proving biocompatibility and acceptability of polymer-formulations. In conclusion, the developed formulation demonstrated controlled release and significant efficacy in delivering these agents and exhibit potential for further clinical development. PMID:22732267

Levy-Nissenbaum, Etgar; Khan, Wahid; Pawar, Rajendra P; Tabakman, Rinat; Naftali, Esmira; Winkler, Ilan; Kaufman, Olga; Klapper, Leah; Domb, Abraham J

2012-09-01

368

Peripheral Neuropathy Caused by Paclitaxel and Docetaxel: An Evaluation and Comparison of Symptoms  

PubMed Central

The purpose of this study was to explore the prevalence, severity, distress, and timing of neuropathic symptoms in cancer patients receiving taxanes and to explore neuropathy-related interference with activities. In this descriptive, cross-sectional study, 68 adult outpatients receiving paclitaxel (n = 36) and docetaxel (n = 32) completed the Chemotherapy Induced Peripheral Neuropathy Assessment Tool and a demographic questionnaire. Muscle or joint aches were the most prevalent symptom. Muscle or joint aches were also the most severe and distressing symptom in persons receiving paclitaxel. Participants receiving paclitaxel reported that neuropathic symptoms interfered with a mean of 7.3 (standard deviation [SD] = 4.1) of 14 activities. Nerve pain was the most severe and distressing symptom in persons receiving docetaxel. Participants receiving docetaxel reported that neuropathic symptoms interfered with a mean of 7.1 (SD = 4.1) of 14 activities. Numbness in the feet was the most frequent or constant symptom in persons receiving paclitaxel or docetaxel. Patients receiving paclitaxel and docetaxel experienced similar symptoms of peripheral neuropathy and interference with activities. Continued focus on treatment of painful neuropathy including myalgias and arthralgias is needed.

Tofthagen*, Cindy; McAllister, R. Denise; Visovsky, Constance

2013-01-01

369

Synthesis and biological evaluation of a peptide-paclitaxel conjugate which targets the integrin ?v??.  

PubMed

The integrin ?(v)?(6) is an emergent biomarker for non-small cell lung cancer (NSCLC) as well as other carcinomas. We previously developed a tetrameric peptide, referred to as H2009.1, which binds ?(v)?(6) and displays minimal affinity for other RGD-binding integrins. Here we report the use of this peptide to actively deliver paclitaxel to ?(v)?(6)-positive cells. We synthesized a water soluble paclitaxel-H2009.1 peptide conjugate in which the 2'-position of paclitaxel is attached to the tetrameric peptide via an ester linkage. The conjugate maintains its specificity for ?(v)?(6)-expressing NSCLC cells, resulting in selective cytotoxicity. Treatment of ?(v)?(6)-positive cells with the conjugate results in cell cycle arrest followed by induction of apoptosis in the same manner as free paclitaxel. However, initiation of apoptosis and the resultant cell death is delayed compared to free drug. The conjugate demonstrates anti-tumor activity in a H2009 xenograft model of NSCLC with efficacy comparable to treatment with free paclitaxel. PMID:21868241

Li, Shunzi; Gray, Bethany Powell; McGuire, Michael J; Brown, Kathlynn C

2011-09-15

370

A clinical and pharmacokinetic study of the combination of carboplatin and paclitaxel for epithelial ovarian cancer.  

PubMed Central

The aim of this phase I study was to determine the maximum tolerated dose of a 3-h infusion of paclitaxel, combined with carboplatin at a fixed AUC of 7 mg ml-1 min every 4 weeks for up to six cycles and to evaluate any possible pharmacokinetic interaction. Twelve chemonaive patients with ovarian cancer were treated with paclitaxel followed by a 30-min infusion of carboplatin. Paclitaxel dose was escalated from 150 mg m-2 to 225 mg m-2 in cohorts of three patients. Carboplatin dose was based on renal function. Pharmacokinetic studies were performed in nine patients (at least two at each dose level). A total of 66 courses were evaluable for assessment. Grade 3 or 4 neutropenia was seen in 70% of the courses, however hospitalization was not required. Grade 3 or 4 thrombocytopenia occurred in 24% of the courses. Alopecia, myalgia and peripheral neuropathy were common but rarely severe. The pharmacokinetics of paclitaxel was non-linear and did not appear to be influenced by co-administration of carboplatin. The AUC of carboplatin was 7.0 +/- 1.4 mg ml-1 min, indicating that there was no pharmacokinetic interaction. The combination of carboplatin and paclitaxel may be administered as first-line treatment for advanced ovarian cancer. Although myelosuppression is the dose-limiting toxicity of the component drugs, the severity of thrombocytopenia was less than anticipated. The results of this study, with only a small number of patients, need to be confirmed in future investigations.

Siddiqui, N.; Boddy, A. V.; Thomas, H. D.; Bailey, N. P.; Robson, L.; Lind, M. J.; Calvert, A. H.

1997-01-01

371

Characterization of PEG-iron oxide hydrogel nanocomposites for dual hyperthermia and paclitaxel delivery.  

PubMed

Hyperthermia, the heating of tissue from 41 to 45?°C, has been shown to improve the efficacy of cancer therapy when used in conjunction with irradiation and/or chemotherapy. In this work, hydrogel nanocomposites have been developed that can control the delivery of both heat and a chemotherapeutic agent (e.g. paclitaxel). The nanocomposites studied involve a stealth, poly(ethylene glycol) (PEG)-based system comprised of PEG (n?=?1000) methyl ether methacrylate and PEG (n?=?400) dimethacrylate with iron oxide nanoparticles physically entrapped within the hydrogel matrices. The capability of the hydrogel nanocomposites to be heated in an alternating magnetic field was demonstrated. The heating of the hydrogel systems was dependent on the crosslinking of the hydrogel network where hydrogels with lower swelling ratios were found to heat to a greater extent than those with higher ratios. In addition, paclitaxel was shown to exhibit non-Fickian release from the hydrogel systems, with the amount of drug released dependent on the hydrogel network structure. Three cell lines: M059K (glioblastoma), MDA MB 231 (breast carcinoma), and A549 (lung adenocarcinoma) were exposed to paclitaxel only, hyperthermia only, and both paclitaxel and hyperthermia to determine if a synergistic cytotoxic effect was possible for these cell lines. The efficacy of paclitaxel was greater with hyperthermia for the A549 cells; however, the M059K and MDA MB 231 did not show the same response. PMID:23683041

Meenach, Samantha A; Shapiro, Jenna M; Hilt, J Zach; Anderson, Kimberly W

2013-01-01

372

Cytotoxicity of paclitaxel in breast cancer is due to chromosome missegregation on multipolar spindles.  

PubMed

The blockbuster chemotherapy drug paclitaxel is widely presumed to cause cell death in tumors as a consequence of mitotic arrest, as it does at concentrations routinely used in cell culture. However, we determine here that paclitaxel levels in primary breast tumors are well below those required to elicit sustained mitotic arrest. Instead, cells in these lower concentrations of drug proceed through mitosis without substantial delay and divide their chromosomes on multipolar spindles, resulting in chromosome missegregation and cell death. Consistent with these cell culture data, most mitotic cells in primary human breast cancers contain multipolar spindles after paclitaxel treatment. Contrary to the previous hypothesis, we find that mitotic arrest is dispensable for tumor regression in patients. These results demonstrate that mitotic arrest is not responsible for the efficacy of paclitaxel, which occurs because of chromosome missegregation on highly abnormal, multipolar spindles. This mechanistic insight may be used to improve selection of future antimitotic drugs and to identify a biomarker with which to select patients likely to benefit from paclitaxel. PMID:24670687

Zasadil, Lauren M; Andersen, Kristen A; Yeum, Dabin; Rocque, Gabrielle B; Wilke, Lee G; Tevaarwerk, Amye J; Raines, Ronald T; Burkard, Mark E; Weaver, Beth A

2014-03-26

373

Paclitaxel sensitivity in relation to ABCB1 expression, efflux and single nucleotide polymorphisms in ovarian cancer.  

PubMed

ABCB1 (adenosine triphosphate-binding cassette transporter B1) mediates cellular elimination of many chemotherapeutic agents including paclitaxel, which is commonly used to treat ovarian cancer. A significant association between common single nucleotide polymorphisms (SNPs) in ABCB1 and progression-free survival has been reported in patients with ovarian cancer. Variable paclitaxel clearance due to genotype specific differences in ABCB1 activity in cancer cells and/or normal tissues may underlie the association. Using cell-based models, we evaluated the correlations between ABCB1 expression, polymorphisms, transporter activity and paclitaxel sensitivity in ovarian cancer (n = 10) and lymphoblastoid (n = 19) cell lines. Close associations between ABCB1 expression, transporter function and paclitaxel sensitivity were found in lymphoblastoid cell lines, although we could not demonstrate an association with common SNPs. In ovarian cancer cell lines, ABCB1 expression was low and the association between expression and function was lost. These results suggest that ABCB1 related survival difference in ovarian cancer patients is more likely to be due to differential whole body paclitaxel clearance mediated by normal cells rather than a direct effect on cancer cells. PMID:24810093

Gao, Bo; Russell, Amanda; Beesley, Jonathan; Chen, Xiao Qing; Healey, Sue; Henderson, Michelle; Wong, Mark; Emmanuel, Catherine; Galletta, Laura; Johnatty, Sharon E; Bowtell, David; Haber, Michelle; Norris, Murray; Harnett, Paul; Chenevix-Trench, Georgia; Balleine, Rosemary L; Defazio, Anna

2014-01-01

374

Antitumor activity of Triolimus: a novel multidrug-loaded micelle containing Paclitaxel, Rapamycin, and 17-AAG.  

PubMed

Triolimus is a first-in-class, multidrug-loaded micelle containing paclitaxel, rapamycin, and 17-AAG. In this study, we examine the antitumor mechanisms of action, efficacy, and toxicity of Triolimus in vitro and in vivo. In vitro cytotoxicity testing of Triolimus was conducted using two aggressive adenocarcinomas including the lung cancer cell line, A549, and breast cancer cell line, MDA-MB-231. The three-drug combination of paclitaxel, rapamycin, and 17-AAG displayed potent cytotoxic synergy in both A549 and MDA-MB-231 cell lines. Mechanistically, the drug combination inhibited both the Ras/Raf/mitogen-activated protein kinase and PI3K/Akt/mTOR pathways. Triolimus was advanced into tumor xenograft models for assessment of efficacy, toxicity, and mechanisms of action. In vivo, a three-infusion schedule of Triolimus inhibited A549 and MDA-MB-231 tumor growth far more potently than paclitaxel-containing micelles and effected tumor cures in MDA-MB-231 tumor-bearing animals. Tumor growth delays resulted from a doubling in tumor cell apoptosis and a 50% reduction in tumor cell proliferation compared with paclitaxel-containing micelles. Enhanced antitumor efficacy was achieved without clinically significant increases in acute toxicity. Thus, Triolimus displays potent synergistic activity in vitro and antitumor activity in vivo with comparable toxicity to paclitaxel. These observations provide strong support for further development of Triolimus and an important proof of concept for safe, effective nanoparticle-based delivery of three complementary anticancer agents. PMID:22896668

Hasenstein, Jason R; Shin, Ho-Chul; Kasmerchak, Kelsey; Buehler, Darya; Kwon, Glen S; Kozak, Kevin R

2012-10-01

375

E2F Inhibition Synergizes with Paclitaxel in Lung Cancer Cell Lines  

PubMed Central

The CDK/Rb/E2F pathway is commonly disrupted in lung cancer, and thus, it is predicted that blocking the E2F pathway would have therapeutic potential. To test this hypothesis, we have examined the activity of HLM006474 (a small molecule pan-E2F inhibitor) in lung cancer cell lines as a single agent and in combination with other compounds. HLM006474 reduces the viability of both SCLC and NSCLC lines with a biological IC50 that varies between 15 and 75 µM, but with no significant difference between the groups. Combination of HLM006474 with cisplatin and gemcitabine demonstrate little synergy; however, HLM006474 synergizes with paclitaxel. Surprisingly, we discovered that brief treatment of cells with HLM006474 led to an increase of E2F3 protein levels (due to de-repression of these promoter sites). Since paclitaxel sensitivity has been shown to correlate with E2F3 levels, we hypothesized that HLM006474 synergy with paclitaxel may be mediated by transient induction of E2F3. To test this, H1299 cells were depleted of E2F3a and E2F3b with siRNA and treated with paclitaxel. Assays of proliferation showed that both siRNAs significantly reduced paclitaxel sensitivity, as expected. Taken together, these results suggest that HLM006474 may have efficacy in lung cancer and may be useful in combination with taxanes.

Kurtyka, Courtney A.; Chen, Lu; Cress, W. Douglas

2014-01-01

376

Paclitaxel induces apoptosis in Saos-2 cells with CD95L upregulation and Bcl-2 phosphorylation.  

PubMed

We examined the effect of paclitaxel on human osteoblastic cells Saos-2 to determine if paclitaxel can affect proliferation and apoptosis. We used a p53-negative cell line in order to mimic the loss of function frequently observed at the clinical level. Paclitaxel induced cell death in a dose- and time-dependent manner. Marked nuclear condensation and fragmentation of chromatin were observed by Hoechst 33258 stain, DNA ladder formation, electron microscopy, and flow cytometry at concentrations as low as 100 nM, a concentration which can be achieved by infusion in human plasma. At 100 nM, paclitaxel induced a G2 arrest at 8 h of treatment. The cells then continued to accumulate in G2 until 72 h when the percentage of apoptotic events reached 54%. At the molecular level, Bcl-2 protein was phosphorylated at 16 h and PARP protein was cleaved, indicating the activation of caspase-3-like proteases. Caspase inhibitors Z-VAD-FMK and Z-DEVD-FMK rescued Saos-2 cells from paclitaxel-induced apoptosis. CD95 expression was constantly high, while CD95L showed a threefold increase in expression. This suggests that, following the G2 arrest, apoptosis is induced through the CD95/CD95L system. PMID:10502406

Pucci, B; Bellincampi, L; Tafani, M; Masciullo, V; Melino, G; Giordano, A

1999-10-10

377

Paclitaxel sensitivity in relation to ABCB1 expression, efflux and single nucleotide polymorphisms in ovarian cancer  

PubMed Central

ABCB1 (adenosine triphosphate-binding cassette transporter B1) mediates cellular elimination of many chemotherapeutic agents including paclitaxel, which is commonly used to treat ovarian cancer. A significant association between common single nucleotide polymorphisms (SNPs) in ABCB1 and progression-free survival has been reported in patients with ovarian cancer. Variable paclitaxel clearance due to genotype specific differences in ABCB1 activity in cancer cells and/or normal tissues may underlie the association. Using cell-based models, we evaluated the correlations between ABCB1 expression, polymorphisms, transporter activity and paclitaxel sensitivity in ovarian cancer (n = 10) and lymphoblastoid (n = 19) cell lines. Close associations between ABCB1 expression, transporter function and paclitaxel sensitivity were found in lymphoblastoid cell lines, although we could not demonstrate an association with common SNPs. In ovarian cancer cell lines, ABCB1 expression was low and the association between expression and function was lost. These results suggest that ABCB1 related survival difference in ovarian cancer patients is more likely to be due to differential whole body paclitaxel clearance mediated by normal cells rather than a direct effect on cancer cells.

Gao, Bo; Russell, Amanda; Beesley, Jonathan; Chen, Xiao Qing; Healey, Sue; Henderson, Michelle; Wong, Mark; Emmanuel, Catherine; Galletta, Laura; Johnatty, Sharon E.; Bowtell, David; Bowtell, David; Chenevix-Trench, Georgia; deFazio, Anna; Gertig, Dorota; Green, Adle; Webb, Penelope; Hung, Jillian; Moore, Sue; Traficante, Nadia; Fereday, Sian; Harrap, Karen; Sadkowsky, Troy; Pandeya, Nirmala; Stuart-Harris, Robin; Kirsten, Fred; Rutovitz, Josie; Clingan, Peter; Glasgow, Amanda; Proietto, Anthony; Braye, Stephen; Otton, Greg; Shannon, Jennifer; Bonaventura, Tony; Stewart, James; Begbie, Stephen; Friedlander, Michael; Bell, David; Baron-Hay, Sally; Ferrier, Alan; Gard, Greg; Nevell, David; Pavlakis, Nick; Valmadre, Sue; Young, Barbara; Camaris, Catherine; Crouch, Roger; Edwards, Lyndal; Hacker, Neville; Marsden, Donald; Robertson, Greg; Beale, Phillip; Beith, Jane; Carter, Jonothan; Dalrymple, Chris; Hamilton, Anne; Houghton, Roger; Russell, Peter; Links, Matthew; Grygiel, John; Hill, Jane; Brand, Alison; Byth, Karen; Jaworski, Richard; Harnett, Paul; Sharma, Raghwa; Achen, Anita; Wain, Gerard; Ward, Bruce; Papadimos, David; Crandon, Alex; Cummings, Margaret; Horwood, Ken; Obermair, Andreas; Perrin, Lew; Wyld, David; Nicklin, Jim; Davy, Margaret; Oehler, Martin K; Hall, Chris; Dodd, Tom; Healy, Tabitha; Pittman, Ken; Henderson, Doug; Miller, John; Pierdes, John; Blomfield, Penny; Challis, David; McIntosh, Robert; Parker, Andrew; Brown, Bob; Rome, Robert; Allen, David; Grant, Peter; Hyde, Simon; Laurie, Rohan; Robbie, Melissa; Healy, David; Jobling, Tom; Manolitsas, Tom; McNealage, Jane; Rogers, Peter; Susil, Beatrice; Sumithran, Eric; Simpson, Ian; Phillips, Kelly; Rischin, Danny; Fox, Stephen; Johnson, Daryl; Waring, Paul; Lade, Stephen; Loughrey, Maurice; O’Callaghan, Neil; Murray, William; Billson, Virginia; Pyman, Jan; Neesham, Debra; Quinn, Michael; Underhill, Craig; Bell, Richard; Ng, Leong-Fook; Blum, Robert; Ganju, Vinod; Hammond, Ian; Leung, Yee; McCartney, Anthony; Buck, Martin; Haviv, Izak; Purdie, David; Whiteman, David; Zeps, Nikolajs; Malt, Mary-Rose; Mellon, Anne; Robertson, Randall; Bergh, Trish Vanden; Jones, Marian; Mackenzie, Patricia; Maidens, Jane; Nattress, Kath; Chiew, Yoke-Eng; Stenlake, Annie; Sullivan, Helen; Alexander, Barbara; Ashover, Pat; Brown, Sue; Corrish, Tracy; Green, Lyn; Jackman, Leah; Ferguson, Kaltin; Martin, Karen; Martyn, Adam; Ranieri, Barbara; White, Jo; Jayde, Victoria; Bowes, Leanne; Mamers, Pamela; Galletta, Laura; Giles, Debra; Hendley, Joy; Alsop, Katherine; Schmidt, Trudy; Shirley, Helen; Ball, Colleen; Young, Cherry; Viduka, Suzanna; Tran, Hoa; Bilic, Sanela; Glavinas, Lydia; Brooks, Julia; Haber, Michelle; Norris, Murray; Harnett, Paul; Chenevix-Trench, Georgia; Balleine, Rosemary L.; deFazio, Anna

2014-01-01

378

Synergistic Effect of COX-2 Inhibitor on Paclitaxel-Induced Apoptosis in the Human Ovarian Cancer Cell Line OVCAR-3  

PubMed Central

Purpose Celecoxib, a highly selective cyclooxygenase-2 inhibitor, regulates apoptosis of several types of human cancer cells. The purpose of this study was to investigate whether celecoxib in combination with paclitaxel modulates apoptosis of ovarian cancer cells, and to identify the signal pathway by which celecoxib mediates apoptosis. Materials and Methods OVCAR-3 cells were exposed to paclitaxel (20 µM) in the absence or presence of celecoxib (10 µM). Cell viability was evaluated using a Cell Counting Kit-8 assay. Apoptosis was evaluated using Annexin-V/7-aminoactinomycin D staining and a cellular DNA fragmentation enzyme-linked immunosorbent assay. Caspase-3, -9, and cleavage of poly ADP-ribose polymerase (PARP) were determined by western blotting. Expression of nuclear factor-?B (NF-?B) and vascular endothelial growth factor (VEGF) and Akt activation were assessed using reverse transcriptase-polymerase chain reaction and western blotting. Results Celecoxib enhanced paclitaxel-induced growth inhibition of OVCAR-3 cells. Celecoxib significantly increased paclitaxel-induced apoptosis of OVCAR-3 cells. Pretreatment with celecoxib also increased activation of caspase-9, -3 and cleaved PARP following paclitaxel-treatment. Exposure of OVCAR-3 cells to celecoxib in combination with paclitaxel resulted in downregulation of NF-?B activation and VEGF expression. Furthermore, combining celecoxib and paclitaxel inhibited phosphorylation of Akt. Conclusion OVCAR-3 cells were sensitized to paclitaxel-induced apoptosis by celecoxib through downregulation of NF-?B and Akt activation, suggesting that celecoxib may work synergistically with paclitaxel to inhibit different targets and ultimately produce anticancer effects. Combining celecoxib with paclitaxel may prove beneficial in the clinical treatment of ovarian cancer.

Kim, Hee Jung; Yim, Ga Won; Nam, Eun Ji

2014-01-01

379

Constitutive Androstane Receptor Ligands Modulate the Anti-Tumor Efficacy of Paclitaxel in Non-Small Cell Lung Cancer Cells  

PubMed Central

Background Lung tumors are the leading cause of cancer deaths worldwide and paclitaxel has proven to be useful for patients with lung cancer, however, acquired resistance is a major problem. To overcome this problem, one promising option is the use of Constitutive Androstane Receptor (CAR) ligands in combination with chemotherapeutics against cancer cells. Therefore, we wish to elucidate the effects of CAR ligands on the antineoplastic efficacy of paclitaxel in lung cancer cells. Methodology/Principal Findings Our results from cell viability assays exposing CAR agonist or inverse-agonist to mouse and human lung cancer cells modulated the antineoplastic effect of paclitaxel. The CAR agonists increased the effect of Paclitaxel in 6 of 7 lung cancer cell lines, whereas the inverse-agonist had no effect on paclitaxel cytotoxicity. Interestingly, the mCAR agonist TCPOBOP enhanced the expression of two tumor suppressor genes, namely WT1 and MGMT, which were additively enhanced in cells treated with CAR agonist in combination with paclitaxel. Also, in silico analysis showed that both paclitaxel and CAR agonist TCPOBOP docked into the mCAR structure but not the inverse agonist androstenol. Paclitaxel per se increases the expression of CAR in cancer cells. At last, we analyzed the expression of CAR in two public independent studies from The Cancer Genome Atlas (TCGA) of Non Small Cell Lung Cancer (NSCLC). CAR is expressed in variable levels in NSCLC samples and no association with overall survival was noted. Conclusions/Significance Taken together, our results demonstrated that CAR agonists modulate the antineoplastic efficacy of paclitaxel in mouse and human cancer cell lines. This effect was probably related by the enhanced expression of two tumor suppressor genes, viz. WT1 and MGMT. Most of NSCLC cases present CAR gene expression turning it possible to speculate the use of CAR modulation by ligands along with Paclitaxel in NSCLC therapy.

Fukumasu, Heidge; Rochetti, Arina L.; Pires, Pedro R. L.; Silva, Edson R.; Mesquita, Ligia G.; Strefezzi, Ricardo F.; De Carvalho, Daniel D.; Dagli, Maria L.

2014-01-01

380

Enhanced antitumour activity of 6-hydroxymethylacylfulvene in combination with topotecan or paclitaxel in the MV522 lung carcinoma xenograft model.  

PubMed

6-Hydroxymethylacylfulvene (HMAF; MGI 114; Irofulven) is a semisynthetic analogue of the toxin illudin S, which is a product of the Omphalotus mushroom. MGI 114 induces cytotoxicity against a broad range of solid tumours in vivo, including the drug-refractory MV522 human lung cancer xenograft. In this study, the potential application of MGI 114 in the treatment of lung cancer was explored by evaluating the activity of MGI 114 in combination with either topotecan (TPT) or paclitaxel. Groups of eight nude mice bearing MV522 xenografts were treated with MGI 114, TPT or paclitaxel as single agents and with MGI 114 in combination with TPT or paclitaxel. MGI 114 was administered at doses of 2.5 and 5.0 mg/kg intraperitoneally (i.p.) daily on days 1-5, while TPT and paclitaxel were administered at doses of 0.5 or 1.0 mg/kg and 20 mg/kg, respectively, i.p. on days 1-5. In the single-agent studies, MGI 114, TPT and paclitaxel all resulted in decreased final tumour weights compared with vehicle-treated controls. As single agents, TPT, at the 0.5 mg/kg dose level, and paclitaxel, at the 20 mg/kg dose level, produced partial shrinkages (PSs). All combinations of MGI 114, and either TPT or paclitaxel, produced decrements in final tumour weights compared with monotherapy with the same doses of MGI 114, TPT and paclitaxel. Although all animals treated with the combination of MGI 114 and paclitaxel experienced PSs or complete shrinkages (CSs) (or died), analysis of the time to tumour doubling revealed that the combination of MGI 114 and TPT at 2.5 and 0.5 mg/kg, respectively, was synergistic. These results suggest that cytotoxic activity is enhanced when MGI 114 is combined with either TPT or paclitaxel, and clinical trials to further evaluate these combination regimens are warranted. PMID:11094320

Hammond, L A; Hilsenbeck, S G; Eckhardt, S G; Marty, J; Mangold, G; MacDonald, J R; Rowinsky, E K; Von Hoff, D D; Weitman, S

2000-12-01

381

Efficacy of paclitaxel-eluting stent implantation in hemodialysis patients.  

PubMed

Hemodialysis patients were recognized as a high-risk group for restenosis after percutaneous coronary intervention in the era of the bare-metal stent. Recently, sirolimus-eluting stents (SES) have reduced restenosis and target lesion revascularization (TLR); however, it has been reported that their efficacy in hemodialysis patients is limited. The purpose of this study was to investigate whether paclitaxel-eluting stents (PES) improved angiographic outcomes of hemodialysis patients compared with SES. This study is a retrospective cohort study. We analyzed 54 hemodialysis patients with 87 lesions implanted with PES from February 2007 to September 2008, and 49 hemodialysis patients with 68 lesions implanted with SES from August 2004 to January 2007. Angiographic follow-up after 8-10 months was obtained for 59 lesions (67.8%) in the PES group and 43 lesions (63.2%) in the SES group. At baseline, the PES patients had more peripheral artery disease compared with the SES group (66.7 vs. 34.7%; p = 0.0012). There were no significant differences in the angiographic characteristics or procedural index. The binary restenosis rate was lower in lesions implanted with PES than in those with SES (13.6 vs. 39.5%; p = 0.034). Accordingly, the TLR rate was lower in lesions implanted with PES than with SES (9.3 vs. 26.5%; p = 0.041). Our results suggest that PES is more effective than SES in reducing restenosis and TLR in hemodialysis patients. PMID:21267582

Higashitani, Michiaki; Mori, Fumiaki; Yamada, Norihiro; Arashi, Hiroyuki; Kojika, Asako; Hoshi, Hiromi; Minami, Yuichiro; Yamaguchi, Junichi; Yamauchi, Takao; Takagi, Atsushi; Ogawa, Hiroshi; Hagiwara, Nobuhisa

2011-11-01

382

A Novel Nanoparticle Formulation for Sustained Paclitaxel Delivery  

PubMed Central

Purpose To develop a novel nanoparticle drug delivery system consisting of chitosan and glyceryl monooleate (GMO) for the delivery of a wide variety of therapeutics including paclitaxel. Methods Chitosan/GMO nanoparticles were prepared by multiple emulsion (o/w/o) solvent evaporation methods. Particle size and surface charge were determined. The morphological characteristics and cellular adhesion were evaluated with surface or transmission electron microscopy methods. The drug loading, encapsulation efficiency, in vitro release and cellular uptake were determined using HPLC methods. The safety and efficacy were evaluated by MTT cytotoxicity assay in human breast cancer cells (MDA-MB-231). Results These studies provide conceptual proof that chitosan/GMO can form polycationic nano-sized particles (400 to 700 nm). The formulation demonstrates high yields (98 to 100%) and similar entrapment efficiencies. The lyophilized powder can be stored and easily be resuspended in an aqueous matrix. The nanoparticles have a hydrophobic inner-core with a hydrophilic coating that exhibits a significant positive charge and sustained release characteristics. This novel nanoparticle formulation shows evidence of mucoadhesive properties; a fourfold increased cellular uptake and a 1000-fold reduction in the IC50 of PTX. Conclusion These advantages allow lower doses of PTX to achieve a therapeutic effect, thus presumably minimizing the adverse side effects.

Trickler, W. J.; Nagvekar, A. A.

2008-01-01

383

Targeting of albumin-embedded paclitaxel nanoparticles to tumors  

PubMed Central

We have used tumor-homing peptides to target abraxane, a clinically approved paclitaxel-albumin nanoparticle, to tumors in mice. The targeting was accomplished with two peptides, CREKA, and LyP-1 (CGQKRTRGC). Fluorescein (FAM)-labeled CREKA-abraxane, when injected intravenously into mice bearing MDA-MB-435 human cancer xenografts, accumulated in tumor blood vessels, forming aggregates that contained red blood cells and fibrin. FAM-LyP-1-abraxane co-localized with extravascular islands expressing its receptor, p32. Self-assembled mixed micelles carrying the homing peptide and the label on different subunits accumulated in the same areas of tumors as LyP-1-abraxane, showing that Lyp-1 can deliver intact nanoparticles into extravascular sites. Untargeted, FAM-abraxane was detected in the form of a faint meshwork in tumor interstitium. LyP-1-abraxane produced a statistically highly significant inhibition of tumor growth compared to untargeted abraxane. These results show that nanoparticles can be effectively targeted into extravascular tumor tissue and that targeting can enhance the activity of a therapeutic nanoparticle.

Karmali, Priya Prakash; Kotamraju, Venkata Ramana; Kastantin, Mark; Black, Matthew; Missirlis, Dimitris; Tirrell, Matthew; Ruoslahti, Erkki

2010-01-01

384

Paclitaxel isomerisation in polymeric micelles based on hydrophobized hyaluronic acid.  

PubMed

Physical and chemical structure of paclitaxel (PTX) was studied after its incorporation into polymeric micelles made of hyaluronic acid (HA) (Mw=15kDa) grafted with C6 or C18:1 acyl chains. PTX was physically incorporated into the micellar core by solvent evaporation technique. Maximum loading capacity for HAC6 and HAC18:1 was determined to be 2 and 14wt.%, respectively. The loading efficiency was higher for HAC18:1 and reached 70%. Independently of the derivative, loaded HA micelles had spherical size of approximately 60-80nm and demonstrated slow and sustained release of PTX in vitro. PTX largely changed its form from crystalline to amorphous after its incorporation into the micelle's interior. This transformation increased PTX sensitivity towards stressing conditions, mainly to UV light exposure, during which the structure of amorphous PTX isomerized and formed C3C11 bond within its structure. In vitro cytotoxicity assay revealed that polymeric micelles loaded with PTX isomer had higher cytotoxic effect to normal human dermal fibroblasts (NHDF) and human colon carcinoma cells (HCT-116) than the same micelles loaded with non-isomerized PTX. Further observation indicated that PTX isomer influenced in different ways cell morphology and markers of cell cycle. Taken together, PTX isomer loaded in nanocarrier systems may have improved anticancer activity in vivo than pure PTX. PMID:24614580

Smejkalová, Daniela; Nešporová, Kristina; Hermannová, Martina; Huerta-Angeles, Gloria; Cožíková, Dagmar; Vištejnová, Lucie; Safránková, Barbora; Novotný, Jaroslav; Ku?erík, Ji?í; Velebný, Vladimír

2014-05-15

385

Cellular and clinical pharmacology of the taxanes docetaxel and paclitaxel - a review.  

PubMed

Paclitaxel and docetaxel are active against a range of human cancers. Their antitumor activity is based on stabilization of the microtubule dynamics and thereby disruption of the cell cycle. The taxanes are administered as intravenous solutions in a short administration schedule. Distribution of both taxanes is rapid, with large volumes of distribution and significant binding to plasma proteins. The metabolism of paclitaxel is mediated primarily by the P450 cytochrome enzymes CYP2C8 and CYP3A, whereas docetaxel is only metabolized by CYP3A4. The most common toxicities after intravenous administration are neutropenia, hypersensitivity reactions, neurotoxicity, and alopecia. Several new administration forms are in development; albumin-bound paclitaxel (Abraxane) has recently been registered. Oral formulations of taxanes have been developed, and several are now undergoing phase I trials. New formulations might improve efficacy and safety and could be easier to use. PMID:24637579

de Weger, Vincent A; Beijnen, Jos H; Schellens, Jan H M

2014-04-01

386

[A case of paclitaxel-induced peripheral neuropathy successfully treated by H2-blocker, lafutidine].  

PubMed

We report a 75-year-old female gastric cancer patient with paclitaxel-induced peripheral neuropathy, which was successfully treated by the H2-blocker, lafutidine. From December 2007, she underwent second-line chemotherapy using paclitaxel (80 mg/m/2 day 1, 7, 14/28 days) for peritoneal dissemination which had been refractory to first-line chemotherapy using S-1 (80 mg/m / 2, day 1-28/42 days). After 2 courses, CT showed a complete response (CR) of the peritoneal dissemination. However, at the same time peripheral neuropathy appeared, which was aggravated to grade 3 at the 6th course. Beginning with the 7th course, we administered lafutidine (10 mg/day) for peripheral neuropathy, which recovered to grade 1 after 14 days of lafutidine administration. Lafutidine was administered until July 2008, when peripheral neuropathy kept grade 1 without lafutidine. After 9 courses, paclitaxel therapy failed because of general fatigue. PMID:19755835

Matsumura, Tae; Imamura, Hiroshi; Kishimoto, Tomono; Miyazaki, Yasuhiro; Fujii, Chika; Fujino, Misako; Yasui, Yukako; Anami, Setsuko; Sumita, Rumi; Takada, Natsuko; Fujita, Yuuko; Furukawa, Hiroshi

2009-09-01

387

Diverticular Bleeding of the Colon during Combination Chemotherapy with Bevacizumab and Paclitaxel for Recurrent Breast Cancer  

PubMed Central

Background Bevacizumab has been increasingly used in combination chemotherapy with paclitaxel for treatment of metastatic or recurrent breast cancer. The aim of this report is to underline possible risks associated with the new combination chemotherapy. Case Presentation A 39-year-old woman with recurrent breast cancer was treated with bevacizumab and paclitaxel. Positron emission tomography revealed breast cancer metastasis to the left supraclavicular lymph nodes and right axillary lymph nodes, with no distant metastasis. Results After the third cycle of bevacizumab and paclitaxel, the patient developed a bloody bowel discharge. Emergent colonoscopy demonstrated diverticular bleeding on one of the multiple diverticula in the ascending colon. The bleeding point was successfully clipped colonoscopically. Conclusion The factors for diverticular bleeding are believed to be non-steroidal anti-inflammatory drugs, constipation, and bevacizumab. We recommend reviewing anamneses for diverticulitis, multiple prior abdominal surgeries, peritoneal carcinomatosis, and regular use of certain drugs.

Nakayama, Yoshie; Ito, Yoshinori; Tanabe, Masahiko; Takahashi, Shunji

2013-01-01

388

Taxol-induced sensory disturbance is characterized by preferential impairment of myelinated fiber function in cancer patients.  

PubMed

Taxol produces neuropathic pain with three distinct zones of involvement in the extremities. Most distally is an area of on-going pain and proximal to this is a zone of sensory disturbance but not overt pain. These two areas were confined in all but one case to the glabrous skin of the hands and/or feet. More proximal is an area not recognized by the patients as involved with pain or sensory disturbance yet wherein quantitative sensory tests nevertheless reveal altered sensibility. Impairment of perception to light touch, normally conveyed by myelinated fibers, was dramatically altered in all three areas, being approximately 50-fold greater than normal in areas of pain and sensory disturbance as well as in areas of skin perceived by the patients as not affected. Impairment of perception to sharpness, normally conveyed by small myelinated fibers, was most pronounced in areas of on-going pain, intermediate in areas of sensory disturbance and near baseline in more proximal skin of chemotherapy patients. In contrast to mechanical sensibility, thermal thresholds for warm and heat pain detection were normal throughout. Finally, chemotherapy patients showed paradoxical burning pain to skin cooling that was most pronounced in proximal areas of skin thought to be unaffected by the patients, intermediate in the border zone of altered sensibility and least pronounced in areas of on-going pain. These data suggest that taxol produces a neuropathy characterized by pronounced impairment of function in A-beta myelinated fibers, intermediate impairment of A-delta myelinated fibers, and a relative sparing of C-fibers. PMID:15082135

Dougherty, Patrick M; Cata, Juan P; Cordella, Joseph V; Burton, Allen; Weng, Han-Rong

2004-05-01

389

Stability of paclitaxel with ondansetron hydrochloride or ranitidine hydrochloride during simulated Y-site administration.  

PubMed

The stability of paclitaxel with either ondansetron hydrochloride or ranitidine hydrochloride during simulated Y-site injection at room temperature was studied. Triplicate test solutions of paclitaxel 0.3 and 1.2 mg/mL were admixed 1:1 with ondansetron 0.03 and 0.3 mg/mL (as the hydrochloride salt) or ranitidine 0.5 and 2.0 mg/mL (as the hydrochloride salt). Also, paclitaxel 1.2 mg/mL was admixed 1:1:1 with ondansetron 0.3 mg/mL and ranitidine 2.0 mg/mL. The solutions were stored in glass containers at room temperature, and samples were removed at zero, one, two, and four hours for immediate assay. At the time of the assay and before any dilution, each sample was visually inspected for clarity, color, and precipitation, and the pH was determined. Drug concentrations were measured by stability-indicating high-performance liquid chromatographic procedures. Throughout the study, more than 90% of the initial concentrations of paclitaxel, ondansetron, and ranitidine remained in the solutions. No precipitates, color changes, or haziness was seen. The changes in pH were minor. Paclitaxel in concentrations of 0.3 and 1.2 mg/mL was stable when mixed with either ondansetron (0.03 or 0.3 mg/mL, as the hydrochloride salt) or ranitidine (0.5 or 2.0 mg/mL, as the hydrochloride salt) and stored in glass containers for four hours. Paclitaxel 1.2 mg/mL was also stable when mixed with both ondansetron 0.3 mg/mL and ranitidine 2.0 mg/mL and stored in glass containers for four hours. PMID:7913797

Burm, J P; Jhee, S S; Chin, A; Moon, Y S; Jeong, E; Nii, L; Fox, J L; Gill, M A

1994-05-01

390

miR-375 is upregulated in acquired paclitaxel resistance in cervical cancer  

PubMed Central

Background: Chemo-resistance is one of the key causal factors in cancer death and emerging evidences suggest that microRNAs (miRNAs) have critical roles in the regulation of chemo-sensitivity in cancers. Cervical cancer is one of the most common malignancies in women and insensitive to chemotherapy clinically. Methods: The differentially expressed miRNAs