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1

Overview of paclitaxel (TAXOL).  

PubMed

The history of development of paclitaxel (TAXOL [Bristol-Myers Squibb Co., Princeton, NJ]) is a long story and serves as a model of perseverance for those involved in drug development. Notations of the use of products of the yew tree date back to the Celts, but it was in the 1950s to the 1960s that the National Cancer Institute (NCI) selected the product for trials and the current process began. The active agent was identified in the 1970s, and when its unique mechanism of action was isolated in 1979, interest reemerged. Paclitaxel is an antimicrotubule agent that, unlike other antimicrotubule agents, promotes microtubule assembly. This unique mechanism of action has generated considerable interest in oncology. The clinical trials in the 1980s documented the drug's safety, identified its side effects, and demonstrated its activity in patients with ovarian cancer who had received prior treatment. The many clinical trials currently under way will provide information on the drug's range of activity. Paclitaxel's development has been an arduous process. Its development and supply initially were complicated, but these hurdles have been overcome, and the drug's unique mechanism of action and initial clinical trial results hold promise in the 1990s. PMID:7904376

Martin, V

1993-11-01

2

Paclitaxel (Taxol) in breast cancer.  

PubMed

Paclitaxel (Taxol) is a diterpine plant compound that was isolated initially from the bark of the western yew tree, Taxus brevifolia, but can now be produced by semisynthesis from a renewable source. Paclitaxel is the first new agent in the past decade to have confirmed single agent activity in breast cancer in excess of 50%. A 28% response rate has been reported in doxorubicin-refractory patients. Ongoing studies include attempts to combine paclitaxel with other drugs used for breast cancer treatment and with radiation. PMID:7908664

Arbuck, S G; Dorr, A; Friedman, M A

1994-02-01

3

Combination paclitaxel (Taxol) and doxorubicin therapy for metastatic breast cancer.  

PubMed

Paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) is a very active agent for the treatment of breast cancer, with associated complete response rates of 12% in patients with minimally pretreated metastatic disease. Simultaneous paclitaxel and doxorubicin administration by 72-hour continuous infusion in patients with previously untreated metastatic breast cancer has yielded an overall response rate of 72% with 8% complete responses. No alterations in paclitaxel or doxorubicin pharmacokinetics were observed when the drugs were administered alone versus in combination. Two phase I studies from the M.D. Anderson Cancer Center (Houston, TX) and the University of Indiana (Indianapolis, IN) have shown that administration of a 24-hour paclitaxel infusion prior to doxorubicin results in a significantly higher incidence of mucositis than the reverse sequence. Preliminary pharmacokinetic studies from M.D. Anderson suggest that peak plasma concentration and clearance of doxorubicin are altered by pretreatment with 24-hour paclitaxel. In contrast, in an ongoing phase I study at the Istituto Nazionale Tumori in Milan, Italy, no differences in toxicities have been observed with the combination of intravenous bolus doxorubicin and 3-hour infusional paclitaxel administered by either sequence. Preclinical in vitro and in vivo studies suggest that the combination of paclitaxel and doxorubicin is associated with no or minimal additive antitumor effects. The modest complete response rates that have been observed in patients with metastatic breast cancer to date are in agreement with these observations. A randomized study of paclitaxel versus doxorubicin versus intravenous bolus doxorubicin followed by 24-hour paclitaxel is now being conducted by the Eastern Cooperative Oncology Group. PMID:7939757

O'Shaughnessy, J A; Fisherman, J S; Cowan, K H

1994-10-01

4

Effects of emulsifiers on the controlled release of paclitaxel (Taxol ®) from nanospheres of biodegradable polymers  

Microsoft Academic Search

Paclitaxel (Taxol®) is an antineoplastic drug effective for various cancers especially ovarian and breast cancer. Due to its high hydrophobicity, however, an adjuvant such as Cremophor EL has to be used in its clinical administration, which causes serious side-effects. Nanospheres of biodegradable polymers could be an ideal solution. This study investigates the effects of various emulsifiers on the physical\\/chemical properties

Si-shen Feng; Guofeng Huang

2001-01-01

5

A MATHEMATICAL MODEL FOR THE TRANSPORT OF PACLITAXEL (TAXOL)  

E-print Network

the central nervous system by the blood-brain barrier is a major obstacle for paclitaxel-based treat- ment from entering the central nervous system (CNS) from blood via the wall of brain capillaries. The wall, however, the human brain became a volitional target of xenobiotics. Today, drugs against brain diseases

6

A novel controlled release formulation for the anticancer drug paclitaxel (Taxol ®): PLGA nanoparticles containing vitamin E TPGS  

Microsoft Academic Search

Paclitaxel (Taxol®) is one of the best antineoplastic drugs found from nature in the past decades. Like many other anticancer drugs, there are difficulties in its clinical administration due to its poor solubility. Therefore an adjuvant called Cremophor EL has to be employed, but this has been found to cause serious side-effects. However, nanoparticles of biodegradable polymers can provide an

L Mu; S. S Feng

2003-01-01

7

K252a, KT5720, KT5926, and U98017 support paclitaxel (taxol)-dependent cells and synergize with paclitaxel.  

PubMed

We have used paclitaxel-dependent Tax 2-4 cells to screen for compounds that have paclitaxel-like functional activity. The indolocarbazole serine/threonine kinase inhibitor K252a and analogues such as KT5926, KT5720, and K252b partially support the growth of the paclitaxel-dependent cells in the absence of paclitaxel. A novel kinase inhibitor of similar structure, U98017, supports the growth of the dependent cells to 48% of that seen with paclitaxel. Used in combination with paclitaxel, these compounds reduce the amount of paclitaxel required for maximum growth of the dependent cells. Isobologram analysis demonstrates that these compounds also act synergistically with paclitaxel to promote toxicity in wild-type Chinese hamster ovary cells. These selected indolocarbazoles may act at sites distinct from that of paclitaxel and may specifically inhibit kinases that contribute to the destabilization of microtubules. Other indolocarbazoles such as staurosporine and rebeccamycin do not support paclitaxel-dependent cell growth. Structurally unrelated serine/threonine kinase inhibitors such as H-9 and H-7 or tyrosine kinase inhibitors such as lavendustin do not support the growth of these cells. These results define a screen for functional paclitaxel analogues and suggest that it may be useful to investigate the possible synergy of selected indolocarbazoles and paclitaxel in vivo. PMID:7954419

Abraham, I; Wolf, C L; Sampson, K E; Laborde, A L; Shelly, J A; Aristoff, P A; Skulnick, H I

1994-11-15

8

Phase I study of escalating doses of paclitaxel (Taxol) with fixed doses of ifosfamide, carboplatin, and etoposide.  

PubMed

The combination of ifosfamide (with mesna uroprotection), carboplatin, and etoposide (ICE) has demonstrated activity in a variety of cancers. Paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ), a dipertene compound extracted from the Pacific yew Taxus brevifolia, appeared a good candidate for study as an addition to the ICE regimen (ICE-T) because of its broad antitumor activity, its unique mechanism of action, and its toxicity profile, which was not expected to impact the ICE regimen adversely. In a phase I study, we evaluated the impact of adding escalating doses of paclitaxel (120 mg/m2, 135 mg/m2, 150 mg/m2, and 175 mg/m2) to the ICE regimen in 13 previously untreated (with two exceptions) patients with breast cancer, sarcoma, lung cancer, and adenoid cystic carcinoma. In general, ICE-T was well tolerated with some myelosuppression observed. Responses were seen at all dose levels. To date, the maximal tolerated dose of paclitaxel has not been reached; we are currently administering 175 mg/m2. PMID:7610396

Boros, L; Garrow, G C; Asbury, R F; Chang, A Y

1995-06-01

9

Taxol reactions.  

PubMed

Paclitaxel (Taxol) a taxane antineoplastic agent causing irreversible microtubule aggregation with activity against breast, ovarian, lung, head and neck, bladder, testicular, esophageal, endometrial and other less common tumors was derived from the bark of the Pacific yew (Taxus brevifolia). Phase I trials conducted in the late 1980s were almost halted because of the high frequency of hypersensitivity-like reactions. Respiratory distress (dyspnea and/or bronchospasm), hypotension, and angioedema were the major manifestations, but flushing, urticaria, chest, abdomen, and extremity pains were described also. Reactions occurred on first exposure in the majority of cases raising etiologic questions. The vehicle for paclitaxel Cremophor EL (polyoxyethylated castor oil in 50% ethanol) was strongly suspect as a direct (non-immunoglobulin E dependent) histamine releaser. Premedication regimens and longer infusion times lowered the incidence of reactivity allowing phase II and III trials to progress through the early 1990s. The mechanism(s) underlying paclitaxel hypersensitivity-like reactions is still unknown, and clinical data on probable complement and mast cell activation are lacking. The original clinical trial protocols for paclitaxel required discontinuation of therapy for patients who experienced hypersensitivity-like reactions. Here, we review the current etiologic knowledge of these reactions and describe our clinical approach to allow completion of chemotherapy with this powerful plant-derived agent. PMID:12125509

Price, Kursteen S; Castells, Mariana C

2002-01-01

10

Isoprenoid Pathway Optimization for Taxol Precursor Overproduction in Escherichia coli  

E-print Network

Taxol (paclitaxel) is a potent anticancer drug first isolated from the Taxus brevifolia Pacific yew tree. Currently, cost-efficient production of Taxol and its analogs remains limited. Here, we report a multivariate-modular ...

Wang, Y.

11

Taxol-producing Fungi: A New Approach to Industrial Production of Taxol  

Microsoft Academic Search

Produced by and purified from the Pacific yew Taxus brevifolia, taxol (Paclitaxel) has become a widely used cancer drug in clinics. Due to the rapid growing market, current industrial production of taxol by semi-synthesis that consumes large amount of yew trees cannot meet the demand of the market. The discovery of taxol-producing fungus Taxomyces andeanae, an endophyte of T. brevifolia,

Yuan JI; Jian-Nan BI; Bing YAN; Xu-Dong ZHU

2006-01-01

12

[Taxol-producing fungi: a new approach to industrial production of taxol].  

PubMed

Produced by and purified from Taxus brevifolia, Taxol (paclitaxel) has become a widely used cancer drug in clinic. Due to the rapid growing market, current industrial production of taxol by semi-synthesis that consumes large amount of Taxus trees cannot meet the requirement of the market. The discovery of taxol-producing fungus Taxomyces andeanae, an endophyte of T. brevifolia, by Stierle et al (1993), paves a new way to the production of the drug, i.e. employing large-scale fungal fermentation to make Taxol at lower cost and yet higher yield. This review discusses the present problems in taxol production in pharmaceutical industry, the finding and research progress on taxol-producing fungi, and the potential application of fungal fermentation to manufacture this important drug. PMID:16572833

Ji, Yuan; Bi, Jian-Nan; Yan, Bing; Zhu, Xu-Dong

2006-01-01

13

Fabrication, characterization and in vitro release of paclitaxel (Taxol ®) loaded poly (lactic-co-glycolic acid) microspheres prepared by spray drying technique with lipid\\/cholesterol emulsifiers  

Microsoft Academic Search

Spray dry technique was applied to produce paclitaxel loaded microspheres of biodegradable poly (lactic-co-glycolic acid) (PLGA) as an alternative delivery system. Various emulsifiers such as l-?-dipalmitoyl-phosphatidylcholine (DPPC), cholesterol, polyvinyl alcohol (PVA), gelatin were incorporated in order to achieve high encapsulating efficiency of paclitaxel in the microspheres and desired properties for a sustained release. Atomic force microscopy (AFM) and scanning electron

L Mu; S. S Feng

2001-01-01

14

[Pharmacological action of paclitaxel].  

PubMed

Paclitaxel (taxol, Tax) is a novel plant product isolated from the Pacific yew (Taxus brevifolia). It has a unique mechanism of action, because it induces very stable and dysfunctional microtubules. Paclitaxel has a broad spectrum of antineoplastic activity. It has been successfully used in the treatment of ovarian cancer, metastatic breast cancer, lung cancer, carcinoma of the head and neck, malignant melanoma and other human neoplasms. Tax has response rates of 20-36% in patients with refractory ovarian cancer. Toxic effects include myelosuppresion, hypersensitivity reactions, peripheral neuropathy, cardiac disturbances, alopecia. However, studies evaluating the drug still are ongoing paclitaxel seems to be one of the most promising antineoplastic agents. PMID:10344150

Potemski, P; P?uza?ska, A

1999-01-01

15

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.

16

Vitamin E TPGS used as emulsifier in the solvent evaporation\\/extraction technique for fabrication of polymeric nanospheres for controlled release of paclitaxel (Taxol ®)  

Microsoft Academic Search

The d-?-tocopheryl polyethylene glycol 1000 succinate (vitamin E TPGS) was applied in the present investigation as surfactant stabiliser to fabricate paclitaxel-loaded PLGA nanospheres in the solvent evaporation\\/extraction technique with successful achievement. Laser light scattering system (LLS), scanning electron microscopy (SEM), atomic force microscopy (AFM), differential scanning calorimetry (DSC), Fourier transform infra-red spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) were employed

L Mu; S. S Feng

2002-01-01

17

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

18

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

19

The Shape of Things to Come: Structural and Synthetic Studies of Taxol and Related Compounds  

PubMed Central

The history of the development of TaxolTM (paclitaxel) as an anticancer drug is reviewed, and some aspects of the phytochemistry of Taxus species and of the medicinal chemistry of taxol are discussed. The nature of the taxol-tubulin interaction is then described, with an emphasis on studies that led to the discovery and experimental proof of the T-taxol conformation as the tubulin-binding conformation of taxol. The implications of this conformation for future drug development are also briefly covered. PMID:17184797

Kingston, David G. I.

2007-01-01

20

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

21

Biosynthetic studies on taxol  

Microsoft Academic Search

The biosynthesis of the plant antitumor agent, taxol, was studied by feeding radioactive or stable isotope-labeled precursors to cut stems or to inner bark tissue of Taxus brevifolia. The labeled taxol was purified to radiochemical purity and subjected to chemical degradation or was analyzed by electrospray tandem mass spectrometry. It was demonstrated that in the plant taxol is synthesized from

P. E. Fleming; G. Floss; M. Haertel; A. R. Knaggs; A. Lansing; U. Mocek; K. D. Walker

1994-01-01

22

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.

23

Neurotoxicity of Taxol.  

PubMed

Neurotoxicity, manifested primarily by a motor and sensory polyneuropathy, is the principal nonhematological side effect of Taxol. Available evidence suggests that Taxol produces a toxic effect involving either axons or ganglion cell bodies, or both, rather than a myelinopathy. As with other toxic polyneuropathies, patients with preexisting peripheral neuropathies, such as those caused by diabetes mellitus or ethanol, appear to be particularly predisposed to developing neurological toxicity. The incidence and severity of the neuropathic manifestations also appear to be related to the Taxol dose level, the cumulative dose of Taxol, and possibly to the use of Taxol in combination with cisplatin. Rarely, manifestations of autonomic and central nervous system dysfunction occur. Taxol also induces myalgias in the peri-treatment period, especially when used in high doses, and a myopathy has been noted in patients treated with high doses of Taxol administered alone and in combination with cisplatin. Although dose-response relationships for Taxol have not been clearly established, these neuromuscular effects are likely to become a significant clinical problem if higher doses of Taxol are used with hematopoietic colony-stimulating factors. The neuromuscular effects of Taxol, including symptoms, physical and electrophysiological manifestations, and predisposing factors, as well as agents that may be used for neuroprotection, are discussed in this report. PMID:7912516

Rowinsky, E K; Chaudhry, V; Cornblath, D R; Donehower, R C

1993-01-01

24

Paclitaxel Arrests Growth of Intracellular Toxoplasma gondii  

Microsoft Academic Search

Addition of paclitaxel (Taxol) at a concentration of 1 m Mt oToxoplasma gondii-infected human foreskin fi- broblasts arrested parasite multiplication. Division of the T. gondii tachyzoite nucleus was inhibited, leading to syncytium-like parasite structures within the fibroblasts by 24 h after infection and treatment of the cultures. By 4 days after infection and treatment of the cultures with paclitaxel, this

RANDEE ESTES; NICOLAS VOGEL; DOUGLAS MACK; RIMA MCLEOD

1998-01-01

25

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

NASA Astrophysics Data System (ADS)

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 death is still unclear. In this report, CCK-8 was used to assay the inhibition of taxol on the human lung adenocarcinoma (ASTC-a-1) cells viability, confocal fluorescence microscope was used to monitor the morphology changes of cells with taxol treatment. We for the first time describe the characteristics of taxol-induced cells swelling, cytoplasmic vacuolization and cell death. Taxol induced swelling, cytoplasmatic vacuolization and cell death without cell shrinkage and membrane rupture. These features differ from those of apoptosis and resemble the paraptosis, a novel nonapoptotic PCD.

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

2008-02-01

26

Paclitaxel: new uses for an old drug  

PubMed Central

Paclitaxel (Taxol), one of the most important anticancer drugs, has been used for therapy of different types of cancers. Mechanistically, paclitaxel arrests cell cycle and induces cell death by stabilizing microtubules and interfering with microtubule disassembly in cell division. Recently, it has been found that low-dose paclitaxel seems promising in treating non-cancer diseases, such as skin disorders, renal and hepatic fibrosis, inflammation, axon regeneration, limb salvage, and coronary artery restenosis. Future studies need to understand the mechanisms underlying these effects in order to design therapies with specificity. PMID:24591817

Zhang, Dongshan; Yang, Ruhao; Wang, Shixuan; Dong, Zheng

2014-01-01

27

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. PMID:20800500

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

2010-01-01

28

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

PubMed

Novel paclitaxel-mimicking alkaloids were designed and synthesized based on a bioactive conformation of paclitaxel, that is, 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. PMID:20800500

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

2010-10-01

29

Taxol: A New Antineoplastic Agent  

Microsoft Academic Search

Summary Taxol was discovered in extracts of the bark of the western yew (Taxus brevifolia), an evergreen tree in the ancient forest of the Pacific Northwest. Procurement of the bark and isolation of Taxol resulted in a low yield of the drug. Progress has been made in preparation of semisynthetic Taxol and Taxol analogues from 10-deacetyl-baccatin III, a precursor of

K. Diergarten; A. Dreps

1993-01-01

30

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

31

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

Microsoft Academic Search

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

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

2000-01-01

32

Preparation, characterization, cytotoxicity and pharmacokinetics of liposomes containing water-soluble prodrugs of paclitaxel  

Microsoft Academic Search

Paclitaxel (Taxol) is a diterpenoid isolated from Taxus brevifolia, used clinically for the treatment of ovarian and breast cancer. Due to its aqueous insolubility it is administered dissolved in ethanol and Cremophor EL (polyethoxylated castor oil), which has serious side effects. In order to eliminate this vehicle, in previous work we entrapped paclitaxel in conventional and in polyethylene glycol coated

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

2000-01-01

33

Paclitaxel Injection  

MedlinePLUS

... organs where eggs are formed), breast cancer, and lung cancer. Paclitaxel injection with polyoxyethylated castor oil is also ... of your medications or monitor you carefully for side effects. Many other medications may also interact with paclitaxel, ...

34

Total synthesis of taxol.  

PubMed

Taxol, a substance originally isolated from the Pacific yew tree (Taxus brevifolia) more than two decades ago, has recently been approved for the clinical treatment of cancer patients. Hailed as having provided one of the most significant advances in cancer therapy, this molecule exerts its anticancer activity by inhibiting mitosis through enhancement of the polymerization of tubulin and consequent stabilization of microtubules. The scarcity of taxol and the ecological impact of harvesting it have prompted extension searches for alternative sources including semisynthesis, cellular culture production and chemical synthesis. The latter has been attempted for almost two decades, but these attempts have been thwarted by the magnitude of the synthetic challenge. Here we report the total synthesis of taxol by a convergent strategy, which opens a chemical pathway for the production of both the natural product itself and a variety of designed taxoids. PMID:7906395

Nicolaou, K C; Yang, Z; Liu, J J; Ueno, H; Nantermet, P G; Guy, R K; Claiborne, C F; Renaud, J; Couladouros, E A; Paulvannan, K

1994-02-17

35

Peripheral neuropathy induced by paclitaxel: recent insights and future perspectives.  

PubMed

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. PMID:18615126

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

2006-04-01

36

Total synthesis of taxol  

Microsoft Academic Search

TAXOL1-4, a substance originally isolated from the Pacific yew tree (Taxus brevifolia) more than two decades ago, has recently been approved for the clinical treatment of cancer patients. Hailed as having provided one of the most significant advances in cancer therapy5, this molecule exerts its anticancer activity by inhibiting mitosis through enhancement of the polymerization of tubulin and consequent stabilization

K. C. Nicolaou; Z. Yang; J. J. Liu; H. Ueno; P. G. Nantermet; R. K. Guy; C. F. Claiborne; J. Renaud; E. A. Couladouros; K. Paulvannan; E. J. Sorensen

1994-01-01

37

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

38

Isoprenoid pathway optimization for Taxol precursor overproduction in Escherichia coli.  

PubMed

Taxol (paclitaxel) is a potent anticancer drug first isolated from the Taxus brevifolia Pacific yew tree. Currently, cost-efficient production of Taxol and its analogs remains limited. Here, we report a multivariate-modular approach to metabolic-pathway engineering that succeeded in increasing titers of taxadiene--the first committed Taxol intermediate--approximately 1 gram per liter (~15,000-fold) in an engineered Escherichia coli strain. Our approach partitioned the taxadiene metabolic pathway into two modules: a native upstream methylerythritol-phosphate (MEP) pathway forming isopentenyl pyrophosphate and a heterologous downstream terpenoid-forming pathway. Systematic multivariate search identified conditions that optimally balance the two pathway modules so as to maximize the taxadiene production with minimal accumulation of indole, which is an inhibitory compound found here. We also engineered the next step in Taxol biosynthesis, a P450-mediated 5?-oxidation of taxadiene to taxadien-5?-ol. More broadly, the modular pathway engineering approach helped to unlock the potential of the MEP pathway for the engineered production of terpenoid natural products. PMID:20929806

Ajikumar, Parayil Kumaran; Xiao, Wen-Hai; Tyo, Keith E J; Wang, Yong; Simeon, Fritz; Leonard, Effendi; Mucha, Oliver; Phon, Too Heng; Pfeifer, Blaine; Stephanopoulos, Gregory

2010-10-01

39

MiR-634 sensitizes nasopharyngeal carcinoma cells to paclitaxel and inhibits cell growth both in vitro and in vivo  

PubMed Central

Resistance to chemotherapy is one of the key causal factors in cancer death and increasing evidence has revealed that microRNAs (miRNAs) are involved in chemoresistance in many kinds of human cancers. Paclitaxel has been used for treatment of advanced nasopharyngeal carcinoma (NPC); however, treatment failure often occurs due to development of acquired paclitaxel resistance. In this study, based on miRNA microarray screening and qRT-PCR validation, we found six differentially expressed miRNAs in our induced paclitaxel-resistant NPC CNE-1/Taxol cells. Furthermore, we clarified the role of miR-634, most significantly downregulated in the paclitaxel-resistant CNE-1/Taxol, in regulating the paclitaxel sensitivity in NPC cells. We restored miR-634 expression in the CNE-1/Taxol cells by lentivirus infection, and found restoration of miR-634 re-sensitized the CNE-1/Taxol cells to paclitaxel in vitro by MTT assay and colony formation assay. In xenograft mouse model, we found that miR-634 inhibited tumor growth and enhanced paclitaxel sensitivity. Thus, our findings provide important information for the development of targeted gene therapy for reversing paclitaxel resistance in NPC.

Peng, Xiaowei; Cao, Peiguo; He, Dong; Han, Shuang; Zhou, Jianda; Tan, Guolin; Li, Wei; Yu, Fenghui; Yu, Jianjun; Li, Zan; Cao, Ke

2014-01-01

40

Sequential chemo- and radiochemotherapy with weekly paclitaxel (Taxol) and 3D-conformal radiotherapy of stage III inoperable non-small cell lung cancer. Results of a dose escalation study.  

PubMed

The purpose of this study was the determination of the maximum tolerable dose (MTD) of weekly paclitaxel (PX) in combination with 3D-conformal radiotherapy in non-small cell lung cancer (NSCLC) and the evaluation of side effects, patient outcome and tumor response. Thirty-eight patients with inoperable NSCLC, UICC-stage IIIA (n=14)/IIIB (n=24) received two cycles of induction chemotherapy with PX/carboplatin followed by combined radiochemotherapy (60 Gy/6 weeks) with weekly PX which was escalated in cohorts of four patients until dose limiting toxicity (DLT) was reached. Starting level was 40 mg/m(2). 3D-conformal radiotherapy was applied in all patients. Toxicity was determined by WHO criteria. Patients were followed-up 3-monthly. Thirty eight patients have entered the study, 34 patients are evaluable. DLT was esophagitis III degrees, requiring interruption of radiotherapy and was reached at the PX 70 mg/m(2). Two hypersensitivity reactions (50 mg/m(2)) and one leucopenia III degrees (60 mg/m(2)) were observed. Only one patient (60 mg/m(2), 50 Gy) completely aborted treatment. The pneumonitis rate was between 21 and 36% but showed no clear correlation with PX dose. Tumor response (PR and CR) defined by CT-scan 6 weeks following radiotherapy was 88% (30/34). The 1- and 2-year survival rate is 73% and 34%. We conclude that the MTD of weekly PX with 60 Gy normofractionated radiotherapy is 60 mg/m(2). The DLT is esophagitis. Response and survival data of this sequential/combined approach are promising. A minor increase of pulmonary toxicity of irradiation is suspected. PMID:11325487

Willner, J; Schmidt, M; Kirschner, J; Lang, S; Borgmeier, A; Huber, R M; Flentje, M

2001-05-01

41

Success Story: Taxol  

Cancer.gov

Paclitaxel, the most well-known natural-source cancer drug in the United States, is derived from the bark of the Pacific yew tree (Taxus brevifolia) and is used in the treatment of breast, lung, and ovarian cancer, as well as Kaposi's sarcoma.

42

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

43

Genome sequencing and analysis of the paclitaxel-producing endophytic fungus Penicillium aurantiogriseum NRRL 62431  

PubMed Central

Background Paclitaxel (Taxol™) is an important anticancer drug with a unique mode of action. The biosynthesis of paclitaxel had been considered restricted to the Taxus species until it was discovered in Taxomyces andreanae, an endophytic fungus of T. brevifolia. Subsequently, paclitaxel was found in hazel (Corylus avellana L.) and in several other endophytic fungi. The distribution of paclitaxel in plants and endophytic fungi and the reported sequence homology of key genes in paclitaxel biosynthesis between plant and fungi species raises the question about whether the origin of this pathway in these two physically associated groups could have been facilitated by horizontal gene transfer. Results The ability of the endophytic fungus of hazel Penicillium aurantiogriseum NRRL 62431 to independently synthesize paclitaxel was established by liquid chromatography-mass spectrometry and proton nuclear magnetic resonance. The genome of Penicillium aurantiogriseum NRRL 62431 was sequenced and gene candidates that may be involved in paclitaxel biosynthesis were identified by comparison with the 13 known paclitaxel biosynthetic genes in Taxus. We found that paclitaxel biosynthetic gene candidates in P. aurantiogriseum NRRL 62431 have evolved independently and that horizontal gene transfer between this endophytic fungus and its plant host is unlikely. Conclusions Our findings shed new light on how paclitaxel-producing endophytic fungi synthesize paclitaxel, and will facilitate metabolic engineering for the industrial production of paclitaxel from fungi. PMID:24460898

2014-01-01

44

Role of specific apoptotic pathways in the restoration of paclitaxel-induced apoptosis by valspodar in doxorubicin-resistant MCF7 breast cancer cells  

Microsoft Academic Search

Paclitaxel (Taxol®) kills tumor cells by inducing both cellular necrosis and apoptosis. A major impediment to paclitaxel cytotoxicity is the establishment of multidrug resistance whereby exposure to one chemotherapeutic agent results in cross-resistance to a wide variety of other drugs. For example, selection of MCF-7 breast cancer cells for resistance to doxorubicin (MCF-7ADR cells) results in cross-resistance to paclitaxel. This

Antony Chadderton; David J. Villeneuve; Stefan Gluck; Angie F. Kirwan-Rhude; Brian R. Gannon; David E. Blais; Amadeo M. Parissenti

2000-01-01

45

Chemical conjugation of muramyl dipeptide and paclitaxel to explore the combination of immunotherapy and chemotherapy for cancer  

Microsoft Academic Search

Paclitaxel (Taxol®) conjugated to muramyl dipeptide (MDP) is described. Biological testing showed that the conjugation of\\u000a MDP at 2?-O-paclitaxel (2?-\\u000a O\\u000a -MTC-01) not only has antitumor activity, but also have immunoenhancement capacity. Compared with paclitaxel or MDP alone or with\\u000a a mixture of paclitaxel + MDP, 2?-\\u000a O\\u000a -MTC-01 significantly increases the production and expression of TNF-? and IL-12 from

Xuqin Li; Junli Yu; Song Xu; Nan Wang; Hongzhen Yang; Zheng Yan; Guifang Cheng; Gang Liu

2008-01-01

46

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. PMID:23537181

2013-01-01

47

Human liver microsomal metabolism of paclitaxel and drug interactions  

Microsoft Academic Search

Summary  The aim of this study was to investigate the influence of several anticancer drugs and investigational multidrug resistance\\u000a (MDR) reversing agents on the hepatic metabolism of paclitaxel (Taxol) to its primary metabolites, 6 ?-hydroxypaclitaxel (metabolite,\\u000a MA) and 3?-p-hydroxypaclitaxel (metabolite, MB). There is significant inter-individual variability associated with the levels of these two metabolites. In many cases, 6?-hydroxypaclitaxel\\u000a has been observed

P. B. Desai; J. Z. Duan; Y. W. Zhu; S. Kouzi

1998-01-01

48

Initiation, Growth and Immobilisation of Cell Cultures of Taxus spp. for Paclitaxel Production  

Microsoft Academic Search

Paclitaxel (Taxol), a cytotoxic diterpene initially isolated from the bark of Taxus brevifolia (Pacific yew), has been approved for cancer treatment. Since total chemical synthesis is not economical, plant biotechnology can offer an alternative route for the production of this drug. Callus cultures were initiated from different explants of Taxus x media and Taxus cuspidata on various media using different

CHI WAI TANG; Eman Zalat; Ferda Mavituna

49

Negative Impact of Paclitaxel Crystallization on Hydrogels and Novel Approaches for  

E-print Network

32 Negative Impact of Paclitaxel Crystallization on Hydrogels and Novel Approaches for Anticancer the intravenously administration of the drug, process termed as chemotherapy. This technique has brought many. Based in facts we point a delicate issue, Taxol crystallization in hydrogels and its negative impact

Deymier, Pierre

50

Inhibition of Hec1 expression enhances the sensitivity of human ovarian cancer cells to paclitaxel  

PubMed Central

Aim: Hec1, a member of the Ndc80 kinetochore complex, is highly expressed in cancers. The aim of this study was to explore the role and mechanism of action of Hec1 with respect to the cytotoxicity of paclitaxel in ovarian cancer. Methods: Thirty ovarian cancer samples and 6 normal ovarian samples were collected. Hec1 expression in these samples was determined with immunohistochemistry. Ovarian cancer cell lines A2780, OV2008, C13K, SKOV3, and CAOV3 and A2780/Taxol were examined. Cell apoptosis and cell cycle analysis were detected with flow cytometric technique. siRNA was used to delete Hec1 in the cells. The expression of related mRNAs and proteins was measured using RT-PCR and Western blot analysis, respectively. Results: Hec1 expression was significantly higher in ovarian cancer samples than in normal ovarian samples, and was associated with paclitaxel-resistance and poor prognosis. Among the 6 ovarian cancer cell lines examined, Hec1 expression was highest in paclitaxel-resistant A2780/Taxol cells, and lowest in A2780 cells. Depleting Hec1 in A2780/Taxol cells with siRNA decreased the IC50 value of paclitaxel by more than 10-fold (from 590±26.7 to 45.6±19.4 nmol/L). Depleting Hec1 in A2780 cells had no significant effect on the paclitaxel sensitivity. In paclitaxel-treated A2780/Taxol cells, depleting Hec1 significantly increased the cleaved PARP and Bax protein levels, and decreased the Bcl-xL protein level. Conclusion: Hec1 overexpression is associated with the progression and poor prognosis of ovarian cancer. Inhibition of Hec1 expression can sensitize ovarian cancer cells to paclitaxel. PMID:23474708

Mo, Qing-qing; Chen, Ping-bo; Jin, Xin; Chen, Qian; Tang, Lan; Wang, Bei-bei; Li, Ke-zhen; Wu, Peng; Fang, Yong; Wang, Shi-xuan; Zhou, Jian-feng; Ma, Ding; Chen, Gang

2013-01-01

51

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

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. PMID:22988235

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

2012-01-01

53

Independent evaluation of the anatomical and behavioral effects of Taxol in rat models of spinal cord injury.  

PubMed

The goal of the current manuscript was to replicate published data that show intrathecal infusions of Taxol® (paclitaxel), an anti-neoplastic microtubule stabilizing agent, reduce fibrogliotic scarring caused by a dorsal spinal hemisection (DHx) injury and increase functional recovery and growth of serotonergic axons after moderate spinal contusion injury. These experiments were completed as part of an NIH-NINDS contract entitled "Facilities of Research Excellence in Spinal Cord Injury (FORE-SCI) - Replication". Here, data are presented that confirm the anti-scarring effects of Taxol after DHx injury; however, Taxol did not confer neuroprotection or promote serotonergic axon growth nor did it improve functional recovery in a model of moderate spinal contusion injury. Thus, only partial replication was achieved. Possible explanations for disparate results in our studies and published data are discussed. PMID:24999028

Popovich, Phillip G; Tovar, C Amy; Lemeshow, Stanley; Yin, Qin; Jakeman, Lyn B

2014-11-01

54

Taxol Biosynthesis and Molecular Genetics  

Microsoft Academic Search

Biosynthesis of the anticancer drug Taxol in Taxus (yew) species involves 19 steps from the universal diterpenoid progenitor geranylgeranyl diphosphate derived by the plastidial methyl erythritol phosphate pathway for isoprenoid precursor supply. Following the committed cyclization to the taxane skeleton, eight cytochrome P450-mediated oxygenations, three CoA-dependent acyl\\/aroyl transfers, an oxidation at C9, and oxetane (D-ring) formation yield the intermediate baccatin

Rodney Croteau; Raymond E. B. Ketchum; Robert M. Long; Rüdiger Kaspera; Mark R. Wildung

2006-01-01

55

Pharmacokinetics, biodistribution, efficacy and safety of N-octyl- O-sulfate chitosan micelles loaded with paclitaxel  

Microsoft Academic Search

Paclitaxel (Taxol®, PTX) is a promising anti-cancer drug and has been successfully used to treat a wide variety of cancers. Unfortunately, serious clinical side effects are associated with it, which are caused by PTX itself and non-aqueous vehicle containing Cremophor EL. Development of new formulation of PTX with better efficacy and fewer side effects is extremely urgent. In the present

Can Zhang; Guowei Qu; Yingji Sun; Xiaoli Wu; Zhong Yao; Qinglong Guo; Qilong Ding; Shengtao Yuan; Zilong Shen; Qineng Ping; Huiping Zhou

2008-01-01

56

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

PubMed

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. PMID:23388416

Liu, Katherine; Cang, Shundong; Ma, Yuehua; Chiao, Jen Wei

2013-01-01

57

Antitumor effect of taxol-containing liposomes in a taxol-resistant murine tumor model.  

PubMed

Taxol is a promising agent for use in ovarian cancer and other malignancies. One problem associated with taxol is its low aqueous solubility, requiring Cremophor EL (polyethoxylated castor oil) and ethanol as excipients (Diluent 12); these agents cause serious adverse effects. Liposomes containing taxol and phospholipid (in a 1:33 mole ratio, respectively) were prepared from phosphatidylglycerol and phosphatidylcholine in a 1:9 mole ratio. Antitumor effect was evaluated against Colon-26, a taxol-resistant murine tumor. Given as 1, 4, or 9 injections, free taxol given i.v. in Diluent 12 was ineffective at delaying tumor growth at doses < or = 30 mg/kg per injection (the maximum tolerated dose). In contrast, taxol-liposomes were well tolerated at doses greater than or equal to the maximum tolerated dose of free taxol and showed significant tumor growth inhibition at 10-45 mg/kg per injection. PMID:7903197

Sharma, A; Mayhew, E; Straubinger, R M

1993-12-15

58

Biodistribution and pharmacokinetics of a telodendrimer micellar paclitaxel nanoformulation in a mouse xenograft model of ovarian cancer  

PubMed Central

Background A multifunctional telodendrimer-based micelle system was characterized for delivery of imaging and chemotherapy agents to mouse tumor xenografts. Previous optical imaging studies demonstrated qualitatively that these classes of nanoparticles, called nanomicelles, preferentially accumulate at tumor sites in mice. The research reported herein describes the detailed quantitative imaging and biodistribution profiling of nanomicelles loaded with a cargo of paclitaxel. Methods The telodendrimer was covalently labeled with 125I and the nanomicelles were loaded with 14C-paclitaxel, which allowed measurement of pharmacokinetics and biodistribution in the mice using microSPECT/CT imaging and liquid scintillation counting, respectively. Results The radio imaging data showed preferential accumulation of nanomicelles at the tumor site along with a slower clearance rate than paclitaxel formulated in Cremophor EL (Taxol®). Liquid scintillation counting confirmed that 14C-labeled paclitaxel sequestered in nanomicelles had increased uptake by tumor tissue and slower pharmacokinetics than Taxol. Conclusion Overall, the results indicate that nanomicelle-formulated paclitaxel is a potentially superior formulation compared with Taxol in terms of water solubility, pharmacokinetics, and tumor accumulation, and may be clinically useful for both tumor imaging and improved chemotherapy applications. PMID:22605931

Xiao, Wenwu; Luo, Juntao; Jain, Teesta; Riggs, John W; Tseng, Harry P; Henderson, Paul T; Cherry, Simon R; Rowland, Douglas; Lam, Kit S

2012-01-01

59

Phenethyl isothiocyanate and paclitaxel synergistically enhanced apoptosis and alpha-tubulin hyperacetylation in breast cancer cells  

PubMed Central

Combination of phenethyl isothiocyanate (PEITC) and paclitaxel (taxol) has been shown to work synergistically to increase apoptosis and cell cycle arrest in breast cancer cells. In this report, we further explored the mechanisms for the synergistic activity of PEITC and taxol in MCF7 and MDA-MB-231 (MB) breast cancer cell lines. By Western blotting analysis, treatment of MCF7 cells with both PEITC and taxol led to a 10.4-fold and 5.96-fold increase in specific acetylation of alpha-tubulin over single agent PEITC and taxol, respectively. This synergistic effect on acetylation of alpha-tubulin was also seen in MB cells. The combination of PEITC and taxol also reduced expressions of cell cycle regulator Cdk1, and anti-apoptotic protein bcl-2, enhanced expression of Bax and cleavage of PARP proteins. In conclusion, this study provided biochemical evidence for the mechanism of synergistic effect between the epigenetic agent PEITC and the chemotherapeutic agent taxol. PMID:24495785

2014-01-01

60

Phenethyl isothiocyanate and paclitaxel synergistically enhanced apoptosis and alpha-tubulin hyperacetylation in breast cancer cells.  

PubMed

Combination of phenethyl isothiocyanate (PEITC) and paclitaxel (taxol) has been shown to work synergistically to increase apoptosis and cell cycle arrest in breast cancer cells. In this report, we further explored the mechanisms for the synergistic activity of PEITC and taxol in MCF7 and MDA-MB-231 (MB) breast cancer cell lines. By Western blotting analysis, treatment of MCF7 cells with both PEITC and taxol led to a 10.4-fold and 5.96-fold increase in specific acetylation of alpha-tubulin over single agent PEITC and taxol, respectively. This synergistic effect on acetylation of alpha-tubulin was also seen in MB cells. The combination of PEITC and taxol also reduced expressions of cell cycle regulator Cdk1, and anti-apoptotic protein bcl-2, enhanced expression of Bax and cleavage of PARP proteins. In conclusion, this study provided biochemical evidence for the mechanism of synergistic effect between the epigenetic agent PEITC and the chemotherapeutic agent taxol. PMID:24495785

Cang, Shundong; Ma, Yuehua; Chiao, Jen-Wei; Liu, Delong

2014-01-01

61

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

62

Taxol production in nodule cultures of Taxus.  

PubMed

The in vitro synthesis of secondary compounds from plants is one source of scarce and valuable phytopharmaceuticals. Often, some level of cellular or tissue differentiation is needed for the biosynthesis of many of these important compounds. Nodule cultures, consisting of cohesive multicellular units displaying a high degree of differentiation, were initiated from cultured needles of seven Taxus cultivars (Taxus cuspidata, Taxus x media 'Hicksii', Taxus x hunnewelliana 'Richard Horsey', Taxus x media 'Dark Green Spreader', Taxus x media 'L. C. Bobbick', and Taxus brevifolia). Under normal semicontinuous perfusion culture conditions (bimonthly refreshments to yield 0.2% sucrose), only trace amounts of taxol were detected from Taxus nodule cultures. However, with an elevated sucrose level (0.5% or 1.0%), taxol production was enhanced in T. cuspidata nodules to approximately 12 micrograms taxol/g nodule dry weight (dw). Stimulation of taxol production by elevated sucrose levels occurred even in the absence of other nutrients. The effect of increased sucrose on taxol induction does not appear to be due to an osmotic effect in the medium, suggesting that the increase in taxol production may be correlated with a metabolic process within the nodules. Although sucrose had a significant effect on taxol production, taxane precursors or elicitors of terpenes, as well as other plant secondary metabolites, had no effect on the production of taxol from these cultures. In addition to taxol, the higher sucrose levels also induced the production of 7-epi-10-deacetyltaxol, cephalomannine, and 7-epi-10-deacetylcephalomannine, so that total content of these taxanes equaled approximately 39 micrograms taxane/g dw nodules. PMID:8882426

Ellis, D D; Zeldin, E L; Brodhagen, M; Russin, W A; McCown, B H

1996-03-01

63

Targeting of tumor endothelium by RGD-grafted PLGA-nanoparticles loaded with Paclitaxel  

Microsoft Academic Search

Paclitaxel (PTX)-loaded PEGylated PLGA-based nanoparticles (NP) have been previously described as more effective in vitro and in vivo than Taxol®. The aim of this study was to test the hypothesis that our PEGylated PLGA-based nanoparticles grafted with the RGD peptide or RGD-peptidomimetic (RGDp) would target the tumor endothelium and would further enhance the anti-tumor efficacy of PTX. The ligands were

Fabienne Danhier; Benoît Vroman; Nathalie Lecouturier; Nathalie Crokart; Vincent Pourcelle; Hélène Freichels; Christine Jérôme; Jacqueline Marchand-Brynaert; Olivier Feron; Véronique Préat

2009-01-01

64

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. PMID:19111929

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

2008-01-01

65

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

66

In vitro and in vivo study of two types of long-circulating solid lipid nanoparticles containing paclitaxel.  

PubMed

Paclitaxel (Taxol), a diterpenoid isolated from Taxus brevifolia, is effective against several murine tumors, and is one of the most exciting anticancer molecules currently available. Due to its low solubility in water, it is clinically administered with polyethoxylated castor oil (Cremophor EL), which causes serious side effects. Inclusion of paclitaxel in solid lipid nanoparticles (SLNs) has proved to be a good approach to eliminate the need for Cremophor EL and improve the drug's antitumor efficacy. This paper describes the development of two types of long-circulating SLNs as colloidal carriers for paclitaxel. SLNs are constituted mainly of bioacceptable and biodegradable lipids. In vitro release kinetics showed that the release was very slow, the release of paclitaxel from F68-SLN is linear, and the release of paclitaxel from Brij78-SLN followed the Weibull equation. Pharmacokinetics was evaluated in KM mice after injection of paclitaxel formulated in Cremophor EL or in Brij78-SLN and F68-SLN. Encapsulation of paclitaxel in both SLNs produced marked differences compared with the free drug pharmacokinetics. F68-SLN and Brij78-SLN are long-circulating (t 1/2 beta, 10.06 and 4.88 h, respectively) compared with paclitaxel injection (t 1/2 beta, 1.36 h). PMID:11724235

Chen, D B; Yang, T Z; Lu, W L; Zhang, Q

2001-11-01

67

SYNOPSIS Synopsis of the thesis entitled Production of Anticancer Drug Taxol and Its Precursor Baccatin III by Fusarium solani and Their Apoptotic Activity on Human Cancer Cell Lines Submitted by  

E-print Network

Taxol (generic name paclitaxel), a plant?derived antineoplastic agent, was originally isolated from the bark of the Pacific yew, Taxus brevifolia. Obtaining taxol from this source requires destruction of trees. It has been used alone or in combination with other chemotherapeutic agents for the treatment of breast, ovarian as well as many other types of cancer, including non?small cell lung carcinoma, prostate, head and neck cancer, and lymphoma, as well as AIDS? related Kaposi’s sarcoma. The mode of action of taxol against a number of human cancer cells is by preventing the depolymerization of tubulin during cell division. This molecule increases microtubule stability in the cell and induces apoptosis. From yew trees, the yield of taxol is usually between 0.004 to 0.1 % of the dry weight. The commercial isolation of 1 Kg of taxol requires about 6 to 7 tons of T. brevifolia bark obtained from 2000?3000 well?grown trees. The limited supply of the drug has prompted efforts to find alternative sources of taxol. Alternative methods for taxol production, such as chemical synthesis, tissue and cell cultures of the Taxus species are expensive and give low yields. A fermentation process involving any microorganism would be the most desirable means to lower the cost and increase availability. iv SYNOPSIS The first report on the isolation of taxol?producing fungi from Taxus brevifolia appeared in 1993 (Stierle, et al., 1993). Several taxol?producing fungi have been identified since, such as Taxomyces andreanae, Taxodium disticum,

unknown authors

68

Taxol and Related Taxanes. I. Taxanes of Taxus brevifolia Bark  

Microsoft Academic Search

The published procedures for the isolation of taxol from the Pacific yew (Taxus brevifolia) and other species of Taxus are cumbersome, and the yields of taxol are in the range of 0.0075–0.01%. This paper describes a simple and efficient procedure for the isolation of taxol and its major natural analogues from the bark of T. brevifolia consisting of a single

Koppaka V. Rao

1993-01-01

69

Preparation, characterization, cytotoxicity and pharmacokinetics of liposomes containing water-soluble prodrugs of paclitaxel.  

PubMed

Paclitaxel (Taxol) is a diterpenoid isolated from Taxus brevifolia, used clinically for the treatment of ovarian and breast cancer. Due to its aqueous insolubility it is administered dissolved in ethanol and Cremophor EL (polyethoxylated castor oil), which has serious side effects. In order to eliminate this vehicle, in previous work we entrapped paclitaxel in conventional and in polyethylene glycol coated liposomes. However, in neither formulation did we obtain satisfactory entrapment efficiency. In this study we increased the paclitaxel concentration entrapped in liposomes by incorporating different water-soluble prodrugs, such as the 2'-succinyl, 2'-methylpyridinium acetate and 2'-mPEG ester paclitaxel derivatives, in the lipid vesicles. Liposomes containing 2'-mPEG (5000)-paclitaxel showed the best performance in terms of stability, entrapment efficiency and drug concentration (6.5 mgml(-1)). The in vitro cytotoxic activity of this liposomal prodrug was similar to that of the parent drug. The pharmacokinetic parameters for the free and for the liposomal prodrugs fitted a bi-exponential plasma disposition. The most important change in pharmacokinetic values of the prodrug vs. the free drug liposomal formulations was t(1/2)beta, plasma lifetime, which was longer in liposomes containing 2'-mPEG (5000)-paclitaxel. PMID:10640588

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

2000-01-01

70

Camptothecin and taxol: from discovery to clinic.  

PubMed

Camptothecin (CPT) and taxol are secondary metabolites found in the stembark of Camptotheca acuminata, a native of China, and Taxus brevifolia, found in the northwest Pacific coastal region of the USA, respectively. The compounds were isolated through bioassay-guided fractionation of various extracts and through chromatographic fractions. Their unique and hitherto unknown structures were elucidated by nuclear magnetic resonance, mass spectrometry and X-ray analysis. Both compounds have unique mechanisms of antitumor activity; CPT uniquely inhibits an enzyme, topoisomerase I, involved in DNA replication, while taxol binds to a protein, tubulin, thus inhibiting cell division. Taxol has been called the best new anticancer agent developed from natural products, showing particular efficacy against ovarian cancer. CPT and analogs singly or combined with cisplatinum show efficacy against solid tumors, breast, lung, and colorectal, which hitherto have been unaffected by most cancer chemotherapeutic agents. PMID:9213622

Wall, M E; Wani, M C

1996-04-01

71

Inhibition of glycogen synthase kinase 3beta activity with lithium prevents and attenuates paclitaxel-induced neuropathic pain.  

PubMed

Paclitaxel (taxol) is a first-line chemotherapy-drug used to treat many types of cancers. Neuropathic pain and sensory dysfunction are the major toxicities, which are dose-limiting and significantly reduce the quality of life in patients. Two known critical spinal mechanisms underlying taxol-induced neuropathic pain are an increased production of pro-inflammatory cytokines including interleukin-1? (IL-1?) and suppressed glial glutamate transporter activities. In this study, we uncovered that increased activation of glycogen synthase kinase 3beta (GSK3?) in the spinal dorsal horn was concurrently associated with increased protein expressions of GFAP, IL-1? and a decreased protein expression of glial glutamate transporter 1 (GLT-1), as well as the development and maintenance of taxol-induced neuropathic pain. The enhanced GSK3? activities were supported by the concurrently decreased AKT and mTOR activities. The changes of all these biomarkers were basically prevented when animals received pre-emptive lithium (a GSK3? inhibitor) treatment, which also prevented the development of taxol-induced neuropathic pain. Further, chronic lithium treatment, which began on day 11 after the first taxol injection, reversed the existing mechanical and thermal allodynia induced by taxol. The taxol-induced increased GSK3? activities and decreased AKT and mTOR activities in the spinal dorsal horn were also reversed by lithium. Meanwhile, protein expressions of GLT-1, GFAP and IL-1? in the spinal dorsal horn were improved. Hence, suppression of spinal GSK3? activities is a key mechanism used by lithium to reduce taxol-induced neuropathic pain, and targeting spinal GSK3? is an effective approach to ameliorate GLT-1 expression and suppress the activation of astrocytes and IL-1? over-production in the spinal dorsal horn. PMID:24070631

Gao, M; Yan, X; Weng, H-R

2013-12-19

72

Lipopolysaccharide antagonists block taxol-induced signaling in murine macrophages  

PubMed Central

Taxol is the prototype of a new class of microtubule stabilizing agents with promising anticancer activity. Several studies show that taxol mimics the actions of lipopolysaccharide (LPS) on murine macrophages. To investigate the mechanism of taxol-induced macrophage stimulation, we evaluated the ability of Rhodobacter sphaeroides diphosphoryl lipid A (RsDPLA) and SDZ 880.431 to block taxol-induced effects. RsDPLA and SDZ 880.431 are lipid A analogues that lack LPS-like activity, but inhibit the actions of LPS, presumably by blocking critical cellular binding sites. We report that RsDPLA and SDZ 880.431 potently inhibited taxol-induced TNF secretion, gene activation, and protein-tyrosine phosphorylation. The role of microtubules in taxol signaling was investigated. Taxol-induced microtubule bundling in primary and transformed RAW 264.7 macrophages was not blocked by RsDPLA or SDZ 880.431. Taxotere, a semisynthetic taxoid, was more potent than taxol as an inducer of microtubule bundling, but did not induce tumor necrosis factor alpha secretion and gene activation. These data dissociate the microtubule effects of taxol from macrophage stimulation and suggest that taxol stimulates macrophages through an LPS receptor- dependent mechanism. The results underscore the potential of taxol as a tool for studying LPS receptor activation and provide insights into possible therapeutic actions of this new class of drugs. PMID:8101863

1993-01-01

73

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. PMID:24591819

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

2014-01-01

74

Camptothecin and taxol: from discovery to clinic  

Microsoft Academic Search

Camptothecin (CPT) and taxol are secondary metabolites found in the stembark of Camptotheca acuminata, a native of China, and Taxus brevifolia, found in the northwest Pacific coastal region of the USA, respectively. The compounds were isolated through bioassay-guided fractionation of various extracts and through chromatographic fractions. Their unique and hitherto unknown structures were elucidated by nuclear magnetic resonance, mass spectrometry

Monroe E. Wall; Mansukh C. Wani

1996-01-01

75

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

PubMed

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. PMID:22178261

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

2012-03-28

76

Cyclization of geranylgeranyl diphosphate to taxa-4(5),11(12)-diene is the committed step of taxol biosynthesis in Pacific yew.  

PubMed

The biosynthesis of taxol (paclitaxel) and related taxoids in Pacific yew (Taxus brevifolia) is thought to involve the cyclization of geranylgeranyl diphosphate to a taxadiene followed by extensive oxygenation of this diterpene olefin intermediate. A cell-free preparation from sapling yew stems catalyzed the conversion of [1-3H]geranylgeranyl diphosphate to a cyclic diterpene olefin that, when incubated with stem sections, was converted in good radiochemical yield to several highly functionalized taxanes, including 10-deacetyl baccatin III and taxol itself. Addition of the labeled olefin to a yew bark extract, followed by radiochemically guided fractionation, provided sufficient product to establish the structure as taxa-4(5),11(12)-diene by two-dimensional NMR spectroscopic methods. Therefore, the first dedicated step in taxol biosynthesis is the conversion of the universal diterpenoid precursor geranylgeranyl diphosphate to taxa-4(5),11(12)-diene, rather than to the 4(20),11(12)-diene isomer previously suggested on the basis of the abundance of taxoids with double bonds in these positions. The very common occurrence of taxane derivatives bearing the 4(20)-ene-5-oxy functional grouping, and the lack of oxygenated derivatives bearing a 4(5)-double bond, suggest that hydroxylation at C-5 of taxadiene with allylic rearrangement of the double bond is an early step in the conversion of this olefin intermediate to taxol. PMID:7721772

Koepp, A E; Hezari, M; Zajicek, J; Vogel, B S; LaFever, R E; Lewis, N G; Croteau, R

1995-04-14

77

Photodistributed erythema multiforme: paclitaxel-related, photosensitive conditions in patients with cancer.  

PubMed

Paclitaxel (Taxol) is an intravenously administered antineoplastic agent derived from the yew tree, Taxus brevifolia, whose mechanism of action involves inhibition of mitosis. Some of the mucocutaneous reactions to the drug that have been observed include alopecia, mucositis, hypersensitivity reactions (with erythema and urticaria), nail changes, changes occurring at intravenous sites, and radiation recall dermatitis. Less commonly, acral erythema, erythema multiforme, pustular dermatitis, and scleroderma-like changes have been described. A female patient who was receiving adjuvant weekly paclitaxel for the treatment of intraductal breast carcinoma developed photodistributed erythema multiforme and onycholysis after sun exposure to the affected areas. Including this woman, paclitaxel-associated photosensitve conditions have only been reported in 9 female oncology patients: onycholysis (5), erythema multiforme and onycholysis (2), photo-recall phenomenon (1), and subacute cutaneous lupus erythematosus (1). The patients were either receiving treatment for breast carcinoma (8) or lung cancer (1). The skin lesions developed on sun-exposed areas, usually after the patient had received several weekly doses of paclitaxel, and resolved following discontinuation of the drug. Several of the patients were subsequently able to receive additional cycles of paclitaxel without recurrence of their drug-associated photosensitive conditions by concurrently using photoprotection to prevent additional sun exposure to the previously affected sites during treatment. PMID:19180897

Cohen, Philip R

2009-01-01

78

Camptothecin and taxol: discovery to clinic.  

PubMed

Camptothecin (CPT) is a pentacyclic alkaloid isolated from wood and bark of Camptotheca acuminata. Initially it was found to be highly active in a number of mouse in vivo cancer assays. Subsequently, CPT was found to uniquely inhibit an enzyme, topoisomerase I, which is involved in DNA replication. A number of CPT analogs are in advanced clinical trial, and two, Topotecan and CPT-11, have been approved for marketing by the FDA. taxol, a taxane alkaloid, was isolated from Taxus brevifolia. Taxol is a highly cytotoxic compound active in several mouse antitumor assays. It was subsequently found to uniquely inhibit tubulin, a protein involved in mitosis. After clinical evaluation, it has become the drug of choice for treatment of ovarian cancer. PMID:9735871

Wall, M E

1998-09-01

79

Effect of elicitors and a biogenetic precursor on paclitaxel production in cell suspension cultures of Taxus cuspidata var. nana.  

PubMed

To stimulate the production of taxol (paclitaxel) by cell suspension cultures of Taxus cuspidata var. nana, two kinds of elicitors and a biogenetic precursor were used in F4G4 culture medium. Paclitaxel production was enhanced by each elicitor as well as by the biogenetic precursor and by a combination of the two elicitors or one elicitor and the biogenetic precursor. The amount ofpaclitaxel produced (16.6 mg L(-1)) was greatest when the cell suspension cultures were conducted in F4G4 medium containing chito-heptaose (8 mg L(-1)) and jasmonic acid (21 mg L(-1)). The productivity was enhanced 4.1 fold compared to the control. The amount of paclitaxel produced was increased by supplying air to the cultures, though the productivity depended on the amount of air supplied. However, no enhancement of production was observed when a combination of air and chito-heptaose was provided to the cell suspension cultures. PMID:19090188

Tachinbana, Sanro; Muranaka, Toshio; Itoh, Kazutaka

2007-09-01

80

From taxol to Taxol: the changing identities and ownership of an anti-cancer drug.  

PubMed

This paper analyzes the emergence and evolution of taxol, the world's bestselling anti-cancer drug. Over the years taxol has changed its identity, its status as property, and its association with different places (from the old-growth forests of Washington State to the government agencies of Washington, D.C., to laboratories in France). Taxol is not only a profitable pharmaceutical commodity and a substance injected into women with breast and/or ovarian cancer; it is also a natural product found in the bark of Taxus brevifolia (the Pacific yew, which is native to the North American Pacific Northwest) and a chemical substance that was discovered and brought to the point of commercial production in the public sector. We explore its role in several controversies: the destruction of old-growth forests, public participation in policy making, and the privatization of intellectual property and its effect on the price of drugs. PMID:12458837

Walsh, Vivien; Goodman, Jordan

2002-01-01

81

Increased Spinal Cord Na+-K+-2Cl- Cotransporter-1 (NKCC1) Activity Contributes to Impairment of Synaptic Inhibition in Paclitaxel-induced Neuropathic Pain.  

PubMed

Microtubule-stabilizing agents, such as paclitaxel (Taxol), are effective chemotherapy drugs for treating many cancers, and painful neuropathy is a major dose-limiting adverse effect. Cation-chloride cotransporters, such as Na(+)-K(+)-2Cl(-) cotransporter-1 (NKCC1) and K(+)-Cl(-) cotransporter-2 (KCC2), critically influence spinal synaptic inhibition by regulating intracellular chloride concentrations. Here we show that paclitaxel treatment in rats significantly reduced GABA-induced membrane hyperpolarization and caused a depolarizing shift in GABA reversal potential of dorsal horn neurons. However, paclitaxel had no significant effect on AMPA or NMDA receptor-mediated glutamatergic input from primary afferents to dorsal horn neurons. Paclitaxel treatment significantly increased protein levels, but not mRNA levels, of NKCC1 in spinal cords. Inhibition of NKCC1 with bumetanide reversed the paclitaxel effect on GABA-mediated hyperpolarization and GABA reversal potentials. Also, intrathecal bumetanide significantly attenuated hyperalgesia and allodynia induced by paclitaxel. Co-immunoprecipitation revealed that NKCC1 interacted with ?-tubulin and ?-actin in spinal cords. Remarkably, paclitaxel increased NKCC1 protein levels at the plasma membrane and reduced NKCC1 levels in the cytosol of spinal cords. In contrast, treatment with an actin-stabilizing agent had no significant effect on NKCC1 protein levels in the plasma membrane or cytosolic fractions of spinal cords. In addition, inhibition of the motor protein dynein blocked paclitaxel-induced subcellular redistribution of NKCC1, whereas inhibition of kinesin-5 mimicked the paclitaxel effect. Our findings suggest that increased NKCC1 activity contributes to diminished spinal synaptic inhibition and neuropathic pain caused by paclitaxel. Paclitaxel disrupts intracellular NKCC1 trafficking by interfering with microtubule dynamics and associated motor proteins. PMID:25253692

Chen, Shao-Rui; Zhu, Lihong; Chen, Hong; Wen, Lei; Laumet, Geoffroy; Pan, Hui-Lin

2014-11-01

82

Synthesis and characterization of polymeric nanospheres loaded with the anticancer drug paclitaxel and magnetic particles  

NASA Astrophysics Data System (ADS)

We describe the preparation (by nanoprecipitation) and characterization of nanospheres (NPs) for magnetic drug targeting made of a magnetic fluid with poly(ethylene glycol), poly( D, L-lactic- co-glycolic acid) (PLGA), and the anticancer drug paclitaxel (Taxol ®). Infrared spectroscopy confirmed the incorporation of the drug in the PLGA NPs, which were also characterized in terms of morphology, size (typical diameter 200-250 nm) and colloidal stability in aqueous solutions of NaCl. Drug release and in vivo toxicity experiments of the prepared samples were performed. Their stability, magnetic properties (superparamagnetism), and lethal dose were found to be acceptable for the proposed application in cancer therapy.

Závišová, Vlasta; Koneracká, Martina; Mú?ková, Marta; Kop?anský, Peter; Tomašovi?ová, Natália; Lancz, Gábor; Timko, Milan; Pätoprstá, Božena; Bartoš, Peter; Fabián, Martin

2009-05-01

83

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

84

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. PMID:22902506

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

2012-01-01

85

Use of the tubulin bound paclitaxel conformation for structure-based rational drug design.  

PubMed

A new computational docking protocol has been developed and used in combination with conformational information inferred from REDOR-NMR experiments on microtubule bound 2-(p-fluorobenzoyl)paclitaxel to delineate a unique tubulin binding structure of paclitaxel. A conformationally constrained macrocyclic taxoid bearing a linker between the C-14 and C-3'N positions has been designed and synthesized to enforce this "REDOR-taxol" conformation. The novel taxoid SB-T-2053 inhibits the growth of MCF-7 and LCC-6 human breast cancer cells (wild-type and drug resistant) on the same order of magnitude as paclitaxel. Moreover, SB-T-2053 induces in vitro tubulin polymerization at least as well as paclitaxel, which directly validates our drug design process. These results open a new avenue for drug design of next generation taxoids and other microtubule-stabilizing agents based on the refined structural information of drug-tubulin complexes, in accordance with typical enzyme-inhibitor medicinal chemistry precepts. PMID:15797218

Geney, Raphaël; Sun, Liang; Pera, Paula; Bernacki, Ralph J; Xia, Shujun; Horwitz, Susan B; Simmerling, Carlos L; Ojima, Iwao

2005-03-01

86

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

87

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. PMID:22674061

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

2013-01-01

88

Structural significance of the acyl group at the C-10 position and the A ring of the taxane core of paclitaxel for inducing nitric oxide and tumor necrosis factor production by murine macrophages.  

PubMed

The antitumor agent, paclitaxel (Taxol), mimics the actions of lipopolysaccharide (LPS) on murine macrophages (Mphi). Various synthetic analogs of paclitaxel were examined for their potencies to induce nitric oxide (NO) and tumor necrosis factor (TNF) production by murine peritoneal Mphi, and by human peripheral blood cells. The benzoyl group at C-2, the hydroxy group at C-7 and the acetyl group at C-10 were found to be critically important sites to activate murine Mphi. Nor-seco-taxoid analogs lacking the A ring of the taxane core of paclitaxel were inactive, but inhibit paclitaxel- or LPS-induced NO production. All the compounds tested did not induce TNF production by human blood cells. PMID:10930572

Kirikae, T; Ojima, I; Fuero-Oderda, C; Lin, S; Kirikae, F; Hashimoto, M; Nakanoc, M

2000-08-01

89

Metabolic engineering of isoprenoid biosynthesis in Arabidopsis for the production of taxadiene, the first committed precursor of Taxol.  

PubMed

Paclitaxel (Taxol) is a widely used anticancer isoprenoid produced by the secondary metabolism of yew (Taxus sp.) trees. However, only limited amounts of Taxol or related metabolites (taxoids) can be obtained from the currently available sources. In this work we have taken the first step toward genetically engineering the biosynthesis of taxoids in angiosperms. The first committed step in Taxol biosynthesis is the production of taxadiene from geranylgeranyl diphosphate (GGPP), catalyzed by the plastid-localized enzyme taxadiene synthase (TXS). A recombinant T. baccata TXS lacking the putative plastid targeting peptide and fused to a C-terminal histidine (His) tag was shown to be enzymatically active in Escherichia coli. Constitutive production of the full-length His-tagged enzyme in Arabidopsis thaliana plants led to the accumulation of taxadiene and concomitant growth retardation and decreased levels of photosynthetic pigment in transgenic plants. Although these phenotypes may derive from a toxic effect of taxadiene, the lower accumulation of endogenous plastid isoprenoid products such as carotenoids and chlorophylls in transgenic plants also suggests that the constitutive production of an active TXS enzyme might alter the balance of the GGPP pool. Induction of transgene expression using a glucocorticoid-mediated system consistently resulted in a more efficient recruitment of GGPP for the production of taxadiene, which reached levels 30-fold higher than those in plants constitutively expressing the transgene. This accomplishment illustrates the possibility of engineering the production of taxoids and other GGPP-derived isoprenoids in crop plants despite the constraints associated with limited knowledge with regard to regulation of GGPP availability. PMID:15449291

Besumbes, Oscar; Sauret-Güeto, Susanna; Phillips, Michael A; Imperial, Santiago; Rodríguez-Concepción, Manuel; Boronat, Albert

2004-10-20

90

Effects of taxol on isolated rat hepatocyte metabolism.  

PubMed

Taxol is a natural product, isolated from Taxus brevifolia, with increasing clinical applications because of its potent antitumor activity. Although it is mainly metabolized in the liver, its effect on hepatocyte metabolism has been scarcely investigated. In this study, the response of isolated rat hepatocytes to taxol was evaluated by correlating the changes observed in global indexes such as viability and heat dissipation with those produced in oxygen consumption and intracellular metabolites (ATP, fructose 2,6-bisphosphate, and lactate). The results indicate that taxol reduces aerobic metabolism, which induces an insufficient increase of the ATP via anaerobic glycolysis. Moreover, incubations of isolated mitochondria with taxol indicate that the respiratory chain is directly affected by this drug. PMID:8997198

Manzano, A; Roig, T; Bermúdez, J; Bartrons, R

1996-12-01

91

A phase II trial of paclitaxel in squamous cell carcinoma of the head and neck with correlative laboratory studies.  

PubMed

Head and neck cancer is a major cause of cancer-related deaths. In general, early stage head and neck cancers are effectively treated with either radiation or surgery. More advanced tumors often require combined-modality therapy with both radiation therapy and surgery. Recent investigations indicate that the addition of chemotherapy may be helpful. One of the newer chemotherapy agents that appears to have significant activity against head and neck cancer is paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ). Paclitaxel, originally derived from the western yew Taxus brevifolia, acts by increasing the stability of microtubules and preventing mitosis. Recent evidence indicates that the microtubule system is vital to the release of various cytokines and that modulation of cytokine release may play a major role in the drug's antitumor activity. We report a phase II trial of paclitaxel in patients with head and neck cancer, not only to evaluate its clinical effects, but also to study its effect on cytokine release. We assessed interleukin-1 beta (IL-1 beta) and tumor necrosis factor-alpha production by using a sensitive enzyme-linked immunosorbent assay to assess the serum of patients receiving paclitaxel and to detect cytokine release in vitro. The objective response rate was 36%, with 12% complete responses and 24% partial responses. No IL-1 beta or tumor necrosis factor-alpha was detected in patient serum at any time during the infusion of paclitaxel or after overnight incubation with patient monocytes. No proIL-1 beta was detected in in vitro cultures of paclitaxel-treated patient monocytes. When monocytes were stimulated with endotoxin, IL-1 beta production was greatest at 48 hours, suggesting that paclitaxel can prime cells to produce greater quantities of cytokines after a second stimulus. PMID:7597432

Smith, R E; Thornton, D E; Allen, J

1995-06-01

92

Induction of monocyte chemoattractant protein-1 (MCP-1) and its receptor CCR2 in primary sensory neurons contributes to paclitaxel-induced peripheral neuropathy  

PubMed Central

The use of paclitaxel (Taxol®), a microtubule stabilizer, for cancer treatment is often limited by its associated peripheral neuropathy (chemotherapy-induced peripheral neuropathy, CIPN) which predominantly results in sensory dysfunction including chronic pain. Here we show that paclitaxel CIPN was associated with an induction of chemokine monocyte chemoattractant protein-1 (MCP-1) and its cognate receptor CCR2 in primary sensory neurons of dorsal root ganglia (DRG). Immunostaining revealed that MCP-1 was mainly expressed in small nociceptive neurons while CCR2 was expressed in large and medium-sized myelinated neurons. Direct application of MCP-1 consistently induced intracellular calcium increases in DRG large and medium-sized but not small neurons mainly dissociated from paclitaxel- but not vehicle-treated animals. Paclitaxel also induced increased expression of MCP-1 in spinal astrocytes but no CCR2 signal was detected in spinal cord. Local blockade of MCP-1/CCR2 signaling by anti-MCP-1 antibody or CCR2 antisense oligodeoxynucleotides significantly attenuated paclitaxel CIPN phenotypes including mechanical hypersensitivity and loss of intraepidermal nerve fibers (IENFs) in hindpaw glabrous skin. These results suggest that activation of paracrine MCP-1/CCR2 signaling between DRG neurons plays a critical role in the development of paclitaxel CIPN and targeting MCP-1/CCR2 signaling could be a novel therapeutic approach. PMID:23726937

Zhang, Haijun; Boyette-Davis, Jessica A.; Kosturakis, Alyssa K.; Li, Yan; Yoon, Seo-Yeon; Walters, Edgar T.; Dougherty, Patrick M.

2013-01-01

93

Taxol in combination with acute and low dose rate irradiation.  

PubMed

Taxol is an investigational antineoplastic agent which acts by stabilizing microtubules, thereby preventing normal mitosis. It is believed to block cells in the G2/M phase of the cell cycle. The drug is a natural product isolated from the yew, Taxus brevifolia. We have used a cell line derived from human cervical carcinoma to investigate the combination of Taxol with high and low dose rate 137Cs irradiation. An additive effect for Taxol plus radiation was observed; supra-additivity or synergism is not suggested by our data. In the cell line studied, drug concentrations that accumulate cells to some degree in the G2/M phase of the cycle lead to cell lethality, so that no radiosensitizing effect is possible. We have also shown that the cytotoxic effect of Taxol is not limited to the G2/M phase of the cell cycle. In the clinic, Taxol shows promise both as a chemotherapeutic agent and as a possible adjunct to radiation. The present work demonstrates the need for further studies of Taxol plus radiation with a variety of human cell lines of normal and malignant origin. PMID:7972905

Minarik, L; Hall, E J

1994-08-01

94

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

95

A routine experimental protocol for qHNMR illustrated with Taxol.  

PubMed

Quantitative 1H NMR (qHNMR) provides a value-added dimension to the standard spectroscopic data set involved in structure analysis, especially when analyzing bioactive molecules and elucidating new natural products. The qHNMR method can be integrated into any routine qualitative workflow without much additional effort by simply establishing quantitative conditions for the standard solution 1H NMR experiments. Moreover, examination of different chemical lots of taxol (paclitaxel) and a Taxus brevifolia extract as working examples led to a blueprint for a generic approach to performing a routinely practiced 13C-decoupled qHNMR experiment and for recognizing its potential and main limitations. The proposed protocol is based on a newly assembled 13C GARP broadband decoupled proton acquisition sequence that reduces spectroscopic complexity by removal of carbon satellites. The method is capable of providing qualitative and quantitative NMR data simultaneously and covers various analytes from pure compounds to complex mixtures such as metabolomes. Due to a routinely achievable dynamic range of 300:1 (0.3%) or better, qHNMR qualifies for applications ranging from reference standards to biologically active compounds to metabolome analysis. Providing a "cookbook" approach to qHNMR, acquisition conditions are described that can be adapted for contemporary NMR spectrometers of all major manufacturers. PMID:17298095

Pauli, Guido F; Jaki, Birgit U; Lankin, David C

2007-04-01

96

An Endophytic Taxol-Producing Fungus from Taxus media , Cladosporium cladosporioides MD2  

Microsoft Academic Search

Fermentation processes using taxol-producing fungi other than Taxus spp. may be an alternative way to produce taxol, which is an important antitumor agent used widely in the clinic setting.\\u000a In this study, a taxol-producing endophytic fungus strain MD2 was isolated from the inner bark of Taxus media. Strain MD2 produced taxol when grown in potato dextrose liquid medium. The fungal

Peng Zhang; Peng-Peng Zhou; Long-Jiang Yu

2009-01-01

97

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

98

Taxol and related compounds in Korean native yews (Taxus cuspidata).  

PubMed

The concentrations of taxol and related compounds in the bark and needles of Taxus cuspidata grown on Mt. Jiri, Mt. Sobaek, and Cheju Island, and T. cuspidata var. latifolia on Ullung Island in Korea were determined by high performance liquid chromatography (HPLC). The taxane content significantly varied with the location and plant part. The taxol content in the bark of native yews from Mt. Jiri and Mt. Sobaek was high when compared to that reported for Pacific yew (T. brevifolia), whereas bark from trees on Cheju and Ullung islands contained a much lower level. Surprisingly, the needles from Cheju and Ullung islands contained a much higher level of taxol (0.022% and 0.0173%, respectively) than those of intermountain locations (0.0058% to 0.0085%), on the basis of dry weight. The bark and needles of T. cuspidata var. latifolia on Ullung Island also contained relatively high concentrations of 10-deacetylbaccatin III, 0.0497% and 0.0545%, respectively, and indicated that environmental factors may affect the quantity. Taxol in the needles was confirmed by electrospray mass spectrometry. These results suggest that foliage from yew trees growing in their natural habitats on Cheju and Ullung islands may provide a renewable source for taxol. PMID:7617770

Choi, M S; Kwak, S S; Liu, J R; Park, Y G; Lee, M K; An, N H

1995-06-01

99

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®. PMID:20536174

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

100

Solvent optimization on Taxol extraction from Taxus baccata L., using HPLC and LCMS  

Microsoft Academic Search

Background and the purpose of the study: Taxol, a natural antitumor agent, was first isolated from the extract of the bark of Taxus brevifolia Nutt., which is potentially a limited source for Taxol. In the search of an alternative source, optimum and cost benefit extracting solvents, various solvents with different percentage were utilized to extract Taxol from needles of Taxus

2009-01-01

101

Production of taxol and related taxanes in Taxus brevifolia cell cultures: Effect of sugar  

Microsoft Academic Search

Suspension cells of Taxus brevifolia were cultured as an alternative source of taxol and related taxanes. The effects of basal medium, sugar type, and sugar concentration on growth and taxane production were investigated. To induce taxol production, modification of medium composition was necessary. Fructose supported the best taxol yield and the use of high concentration of sugar was desirable. The

Jin-Hoon Kim; Jeong-Hwan Yun; Yong-Soon Hwang; Sang Yo Byuna; Dong-Il Kim

1995-01-01

102

Intraperitoneal Cisplatin and Paclitaxel in Ovarian Cancer  

Microsoft Academic Search

background Standard chemotherapy for newly diagnosed ovarian cancer is a platinum-taxane combination. The Gynecologic Oncology Group conducted a randomized, phase 3 trial that compared intravenous paclitaxel plus cisplatin with intravenous paclitaxel plus intraperitoneal cisplatin and paclitaxel in patients with stage III ovarian cancer. methods We randomly assigned patients with stage III ovarian carcinoma or primary perito- neal carcinoma with no

Deborah K. Armstrong; Brian Bundy; Lari Wenzel; Helen Q. Huang; Rebecca Baergen; Shashikant Lele; Larry J. Copeland; Joan L. Walker; Robert A. Burger

2010-01-01

103

Low-dose paclitaxel ameliorates fibrosis in the remnant kidney model by down-regulating miR-192.  

PubMed

Transforming growth factor (TGF)-? has been shown to play a central role in the development of tubulointerstitial fibrosis, which can be corrected via treatment with paclitaxel. The biology of microRNA (miR) can be modulated by paclitaxel. We hypothesized that paclitaxel may attenuate renal fibrosis in a rat model of remnant kidney disease by inhibiting TGF-? induced-miRs. Rats in groups of 12 were subjected to 5/6 nephrectomy and received low-dose intraperitoneal injection of paclitaxel. Renal functions were assessed at 8 weeks. The TGF-? signalling cascade and ECM proteins were evaluated by real-time polymerase chain reaction (TRT-PCR) and immunofluorescence microscopy. Animals with remnant kidneys developed hypertension, which was not relieved with paclitaxel treatment. However, paclitaxel treatment resulted in dampening the proteinuric response, reduction in serum BUN, creatinine levels and urine protein : creatinine ratio and normalization of creatinine clearance. These effects were accompanied by the inhibition of Smad2/3 activation, attenuation of renal fibrosis and normalization of integrin-linked kinase (ILK), COL(I)A1, COL(IV)A2 and ?-SMA expression. Also, paclitaxel down-regulated the expression of miR-192, miR-217 and miR -377, while miR-15 was up-regulated in the remnant kidney. In vitro, in tubular epithelial cells (NRK-52E), paclitaxel also inhibited TGF-?1-induced Smad2/3 activation and normalized ILK, COL(I)A1, COL(IV)A2 and ?-SMA expression. Furthermore, ChIP analyses indicated that Taxol suppressed Smad3-mediated miR-192 transcriptional activity. Over-expression of miR-192 in NRK-52E mimicked the changes seen in the remnant kidney, while inclusion of miR-192 inhibitor in the culture medium blocked TGF-?1-induced COL(I)A1 and COL(IV)A2 expression, while ILK and ?-SMA were unaffected. These data suggest that low-dose paclitaxel ameliorates renal fibrosis via modulating miR-192 pathobiology and TGF-?/Smad signalling. PMID:21984124

Sun, Lin; Zhang, Dongshan; Liu, Fuyou; Xiang, Xudong; Ling, Guanghui; Xiao, Li; Liu, Yinghong; Zhu, Xuejing; Zhan, Ming; Yang, Yeyi; Kondeti, Vinay K; Kanwar, Yashpal S

2011-11-01

104

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

NASA Astrophysics Data System (ADS)

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 and whether taxol triggers senescence in A549 cells. We found that taxol-induced cytoplasmic vacuolization at 6 or 9 h after treatment with taxol did not decrease but increase at 24 h or 72 h after refreshing the culture medium without taxol, indicating taxol-induced cytoplasmic vacuolization is irreversible. We used SA-?-Gal (senescence-associated ?-galactosidase) to assess whether taxol-induced cell death in cytoplasmic vacuolization fashion is senescence, and found that hydrogen peroxide (H2O2)-treated, but not taxol-treated cells is significantly stained by the SA-?-Gal, a senescence testing kit, indicating that the form of taxol-induced cell death is not senescence.

Wang, Chao-yang; Chen, Tong-Sheng

2011-03-01

105

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

106

PEG-Derivatized Embelin as a Nanomicellar Carrier For Delivery of Paclitaxel to Breast and Prostate Cancers  

PubMed Central

Paclitaxel (PTX) is one of the most effective chemotherapeutic agents for a wide spectrum of cancers, but its therapeutic benefit is often limited by severe side effects. We have developed a micelle-based PTX formulation based on a simple conjugate derived from polyethylene glycol 5000 (PEG5K) and embelin (EB). Embelin is a natural product and exhibits antitumor activity through blocking the activity of X-linked inhibitor of apoptosis protein (XIAP). PEG5K-EB2 conjugate self-assembles to form stable micelles in aqueous solution and efficiently encapsulates hydrophobic drugs such as PTX. PEG5K-EB2 micelles have a relatively low CMC of 0.002mg/mL (0.35?M) with sizes in the range of 20 ~ 30 nm with or without loaded PTX. In vitro cell uptake study showed that the PEG5K-EB2 micelles were efficiently taken up by tumor cells. In vitro release study showed that PTX formulated in PEG5K-EB2 micelles was slowly released over 5 days with much slower release kinetics than that of Taxol formulation. PTX formulated in PEG5K-EB2 micelles exhibited more potent cytotoxicity than Taxol in several cultured tumor cell lines. Total body near infrared fluorescence (NIRF) imaging showed that PEG5K-EB2 micelles were selectively accumulated at tumor site with minimal uptake in major organs including liver and spleen. PTX-loaded PEG5K-EB2 micelles demonstrated an excellent safety profile with a maximum tolerated dose (MTD) of 100–120 mg PTX/kg in mice, which was significantly higher than that for Taxol (15–20 mg PTX/kg). Finally, PTX formulated in PEG5K-EB2 micelles showed superior anti-tumor activity compared to Taxol in murine models of breast and prostate cancers. PMID:23182923

Lu, Jianqin; Huang, Yixian; Zhao, Wenchen; Marquez, Rebecca T.; Meng, Xiaojie; Li, Jiang; Gao, Xiang; Venkataramanan, Raman; Wang, Zhou; Li, Song

2012-01-01

107

In vivo evaluation of novel chitosan graft polymeric micelles for delivery of paclitaxel.  

PubMed

A water-insoluble anti-tumor agent, Paclitaxel (PTX) was successfully incorporated into polymeric micelles formed from new graft copolymers, N-octyl-N-(2-carboxyl-cyclohexamethenyl) chitosan derivatives(OCCC). The objective of this study was to optimize and characterize the novel PTX micelle (PTX-M). Furthermore, the pharmacokinetics, NIR-imaging, biodistribution, and anti-tumor effects of PTX-M were evaluated. The results showed that the PTX-M had high drug loading (43.25%). The Vd and t1/2? of PTX-M were increased by 11.4- and 2.83-fold, respectively, but the plasma AUC of PTX-M was 3.8-fold lower than that of Taxol. Biodistribution study indicated that PTX-M was widely distributed into most tissues, most of them found in liver, spleen, lung, and kidney. This result was similar with NIR(near-infrared)-imaging. Tumor growth was significantly inhibited after intravenous injection of PTX-M. PTX-M showed the enhanced anti-tumor effect and non-toxic effects compared with Taxol, the commercial product of PTX. Therefore, the chitosan-derived micelle system offered a stable and effective platform for cancer chemotherapy with PTX. PMID:20942638

Liu, Jia; Li, Hongxia; Chen, Daquan; Jin, Xiang; Zhao, Xiaoliang; Zhang, Can; Ping, Qineng

2011-04-01

108

[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

109

Biological assessment of triazine dendrimer: toxicological profiles, solution behavior, biodistribution, drug release and efficacy in a PEGylated, paclitaxel construct.  

PubMed

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 to 19.4 nm. Mass spectrometry and light scattering suggest radically different molecular weights with the former approximately 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 nonlinear, ranging from 7 to 20% cumulative release over a 48 h 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 of 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 that of Abraxane. Both formulations were found to be nontoxic at the administered doses, and the dendrimer had an acute MTD greater than the highest dose administered. In a prostate tumor model (PC-3-h-luc), efficacy was observed over 70 days with an arrest of tumor growth and lack of luciferase activity observed in the twice treated cohort. PMID:20481608

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

2010-08-01

110

Bioprocessing of plant in vitro systems for the mass production of pharmaceutically important metabolites: paclitaxel and its derivatives.  

PubMed

Taxol (paclitaxel) and its derivatives are microtubule-stabilizing drugs widely used in the treatment of several types of cancer, including mammary, prostate, ovarian and non-small-cell lung carcinoma, as well as AIDS-associated Kaposi's sarcoma and other types of tumor. Taxanes stabilize microtubules by enhancing their polymerization and inhibiting depolymerization. Microtubule dynamics are crucial to mitotic spindle formation and function; therefore, cells exposed to taxanes are unable to undergo chromosomal separation during mitosis, become arrested in the G2/M phases of the cell cycle, and are subsequently targeted for apoptosis. Plant cell cultures are used for industrial-scale biotechnological production of important bioactive plant secondary metabolites, including the anticancer agent paclitaxel. In the last two decades, there have been numerous empirical approaches to improve the biotechnological production of taxanes, leading to the conclusion that treatment of Taxus sp. cells with methyl jasmonate or other elicitors is the most effective strategy. However, little insight has been gained into how the elicitors increase taxane biosynthesis or how this process is regulated. In recent years, with the help of "omics" tools, a rational approach has provided new information about taxane metabolism and its control. Once pathway bottlenecks have been identified, it will be possible to engineer Taxus sp. cell lines with overexpression of genes that control the flux-limiting steps, thus boosting taxane productivity. This review describes the chemical and biological characterization of paclitaxel and its derivatives and discusses future prospects for their biotechnological production. PMID:23210777

Onrubia, M; Cusidó, R M; Ramirez, K; Hernández-Vázquez, L; Moyano, E; Bonfill, M; Palazon, J

2013-01-01

111

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

112

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

113

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

Microsoft Academic Search

The effect of 0.5-1.0 #M 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 rain)

JOSETTE THURET-CARNAHAN; JEAN-LOUIS BOSSU; ANNE FELTZ; KEITH LANGLEY; DOMINIQUE AUNIS

1985-01-01

114

Structural significance of the benzoyl group at the C-3'-N position of paclitaxel for nitric oxide and tumor necrosis factor production by murine macrophages.  

PubMed

The antitumor agent paclitaxel (Taxol) mimics the actions of lipopolysaccharide (LPS) on murine macrophages (M phi). Recently, we have shown that the benzoyl group at the C-3' position of paclitaxel is the most important site to induce nitric oxide (NO) and tumor necrosis factor (TNF) production by C3H/HeN M phi (Biochem. Biophys. Res. Commun. 210, 678-686, 1996). In the present study, synthetic analogs of paclitaxel with replacement of the C-3'-N position were examined for their potencies to induce NO and TNF production by peritoneal M phi of LPS-responsive C3H/HeN mice and LPS-hyporesponsive C3H/HeJ mice, by human blood cells and human M phi. In this structure-activity relationship study, we found that (i) the p-substitution of the benzoyl group definitely affects the activity to activate C3H/HeN M phi, (ii) the analogs having a methyl or chloro group at the p-position exhibit stronger activity than that of paclitaxel, (iii) there is good correlation between NO and TNF production by the M phi in response to compounds, (iv) the compounds tested do not induce either NO or TNF production by C3H/HeJ M phi or TNF production by human cells, (v) a previous treatment of C3H/HeN M phi with the inactive compounds can hardly affect either paclitaxel- or LPS-induced TNF production by the M phi, (vi) paclitaxel and its analogs marginally affect LPS-induced TNF production by human blood cells, and (vii) there is no correlation between the NO/TNF inducibility to C3H/HeN M phi and growth inhibitory activity against M phi-like J774.1 and J7.DEF3 cells. PMID:9588177

Kirikae, T; Ojima, I; Ma, Z; Kirikae, F; Hirai, Y; Nakano, M

1998-04-28

115

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

116

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

117

Cell-cycle synchronization reverses Taxol resistance of human ovarian cancer cell lines  

PubMed Central

Background Taxol is a powerful chemotherapy agent leading to mitotic arrest and cell death; however, its clinical efficacy has been hampered due to the development of drug resistance. Taxol specifically targets the cell cycle. Progress through mitosis (M stage) is an absolute requirement for drug-induced death because cell death is markedly reduced in cells blocked at the G1-S transition. The measured doubling time for ovarian cancer cells is about 27 h. As such, during treatment with Taxol most of the cells are not in the M stage of the cell cycle. Thus, the effect of cell-cycle synchronization was investigated in regard to reversing Taxol resistance in ovarian cancer cells. Methods Giemsa-Wright staining was used for assessing the morphology of the cells. The doubling time of the cells was calculated using formula as follows: Td?=?In2/slope. The resistant index and cell cycle were measured via MTT assays and flow cytometry. Thymidine was used to induce cell-cycle synchronization, and cell apoptosis rates following exposure to Taxol were measured using a flow cytometer. Results The growth doubling time of two Taxol-resistant cell lines were longer than that of Taxol-sensitive cells. Apoptotic rates in Taxol-sensitive and -resistant cell lines after synchronization and exposure to Taxol were all higher compared to unsynchronized controls (p <0.05). Conclusions Synchronization of the cell-cycle resulted in an increased effectiveness of Taxol toward ovarian cancer cell lines. We speculated that formation of drug resistance toward Taxol in ovarian cancer could be partly attributed to the longer doubling time of these cells. PMID:23899403

2013-01-01

118

Separation and purification of taxol and cephalomannine from Taxus Cuspidada by normal phase chromatography and twice-reversed-phase chromatography  

Microsoft Academic Search

Taxol is a kind of terpene compounds, which was separated from Taxus brevifolia by Wani et al. [1] originally. Because of the special anticancer mechanics and special curative effect for some kinds of tumor, taxol has attracted much attention recently. At present, an effective method used to ob tain taxol is extraction and separation frorm taxus. It is very difficult

Huiru Dong; Lina Luo; Shan Zhou; Pengyu Bi; Kailu Liu; Jingcheng Zhao

2007-01-01

119

Taxol Suppresses Dynamics of Individual Microtubules in Living Human Tumor Cells  

Microsoft Academic Search

Microtubules are intrinsically dynamic polymers, and their dynamics play a crucial role in mitotic spindle assembly, the mitotic checkpoint, and chromosome movement. We hypothesized that, in living cells, suppression of microtubule dynamics is responsible for the ability of taxol to inhibit mitotic progression and cell proliferation. Using quantitative fluorescence video microscopy, we examined the effects of taxol (30 -100 nM)

Anne-Marie C. Yvon; Patricia Wadsworth; Mary Ann Jordan

1999-01-01

120

Taxol-induced meiotic maturation delay, spindle defects, and aneuploidy in mouse oocytes and zygotes  

Microsoft Academic Search

To increase our understanding about the potential risks of chemically-induced aneuploidy, more information about the various mechanisms of aneuploidy induction is needed, particularly in germ cells. Most chemicals that induce aneuploidy inhibit microtubule polymerization. However, taxol alters microtubule dynamics by enhancing polymerization and stabilizing the polymer fraction. We tested the hypothesis that taxol induces meiotic delay, spindle defects, and aneuploidy

John B Mailhes; Mary J Carabatsos; Daniel Young; Steve N London; Maria Bell; David F Albertini

1999-01-01

121

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

122

Taxol partitioning in two-phase plant cell cultures of Taxus brevifolia  

Microsoft Academic Search

An accumulation phase for taxanes was evaluated for its effect on growth and production kinetics in Taxus brevifolia cell cultures. The second phase, tricaprylin, is an eight-carbon triglyceride that favorably partitions taxol secreted into the medium. Cell growth was generally unaffected by the presence of tricaprylin and a moderate increase in taxol synthesis over a 4-week period was observed. Adjustments

M. Collins-Pavao; C.-K. Chin; H. Pedersen

1996-01-01

123

Development of Taxol and other endophyte produced anti-cancer agents.  

PubMed

Taxol is a powerful and complex anti-cancer compound that was first isolated from the bark of the Pacific yew Taxus brevifolia. Although it offered huge potential as an anti-cancer agent, it experienced a long development period, attributed to by its low availability from its traditional source. Research into alternate sources and methods of production for Taxol have been crucial in meeting with demand for the drug. Three main avenues of research have resulted. Firstly, chemical syntheses of this complex diterpene consist of multiple steps and are not economically feasible due to their low yield. Developments have therefore concentrated on enhancing production in vivo. Efforts have been made to understand the enzymatic steps involved in the synthesis within the yew and innovations to produce Taxol and Taxol-like substances in high yield from cell cultures of Taxus species. An alternative stream of research focuses on endophytes as the producer of Taxol. Endophytes can be isolated from the yew tree and produce Taxol in culture. Encouraging findings with endophytes resulted in much interest in the prospect of using endophytes as the producer of Taxol and Taxol-like substances. This review also discusses patents and the future prospects of each of the main streams of production. PMID:18289120

Miller, Kristin; Neilan, Brett; Sze, Daniel M Y

2008-01-01

124

A New Large-Scale Process for Taxol and Related Taxanes from Taxus brevifolia  

Microsoft Academic Search

Purpose. In view of the demonstrated antitumor activity of taxol, ready availability of the drug is important. The current isolation methods starting from the bark of Taxus brevifolia involve multiple manipulations, leading to only taxol and in a yield of 0.01%. A new process consisting of a single reverse phase column is introduced here, and the present purpose is to

Koppaka V. Rao; Jampani B. Hanuman; Claudio Alvarez; Mark Stoy; John Juchum; Richard M. Davies; Ronald Baxley

1995-01-01

125

d-?-Tocopherol Polyethylene Glycol Succinate-Based Redox-Sensitive Paclitaxel Prodrug for Overcoming Multidrug Resistance in Cancer Cells.  

PubMed

To overcome the multidrug resistance (MDR) of P-glycoprotein (P-gp) substrate anticancer drugs, such as paclitaxel (PTX), a novel dual-functional prodrug, D-?-tocopherol polyethylene glycol succinate (TPGS) based PTX prodrug (TPGS-S-S-PTX), was synthesized here to fulfill the synergistic effect of P-gp inhibiting and intracellular redox-sensitive release. The prodrug could self-assemble into stable micelles in physiological environment with a diameter of ?140 nm, while it disassociated in reductive condition and released PTX and TPGS active derivatives rapidly. High cell cytotoxicity in PTX-resistant human ovarian cell line A2780/T was observed with enhanced PTX accumulation due to the P-gp inhibition by the TPGS moiety. The IC50 of TPGS-S-S-PTX was 55% and 91% more effective than that of Taxol (clinical formulation of PTX) and uncleavable TPGS-C-C-PTX prodrug, respectively. This was found to be related with the increased apoptosis/necrosis and cell arrest in G2/M phase. In vivo evaluation of the TPGS-S-S-PTX prodrug exhibited an extended half-life, increased AUC (area under the concentration-time curve), enhanced tumor distribution and significant tumor growth inhibition with reduced side effects as compared to Taxol and TPGS-C-C-PTX. This prodrug has great potential in improving efficiency in the treatment of MDR tumors. PMID:25102234

Bao, Yuling; Guo, Yuanyuan; Zhuang, Xiangting; Li, Dan; Cheng, Bolin; Tan, Songwei; Zhang, Zhiping

2014-09-01

126

Camptothecin and taxol: historic achievements in natural products research.  

PubMed

The research team of Dr. Monroe E. Wall and Dr. Mansukh C. Wani of Research Triangle Institute discovered two first-in-class life-saving chemotherapeutic agents. Camptothecin, first isolated and identified from Camptotheca acuminata, was found to kill cancer cells uniquely via topoisomerase I poisoning. Presently, two first-generation analogues of camptothecin are used to treat ovarian, colorectal, and small-cell lung cancers, and several second-generation analogues are in clinical trials. Taxol, first isolated and identified by Wall and Wani from Taxus brevifolia, was found to inhibit cancer cell growth via the stabilization of microtubules. In 1992, taxol was approved for refractory ovarian cancer and today is used against breast and non-small cell lung cancers and in Kaposi's sarcoma. While there have been numerous reviews of these molecules individually, this review offers an integrated account of the research team of "Wall and Wani" and the significance of their discoveries to chemistry, biology, and clinical medicine. PMID:14987046

Oberlies, Nicholas H; Kroll, David J

2004-02-01

127

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. PMID:19360801

Sun, Liang; Simmerling, Carlos; Ojima, Iwao

2011-01-01

128

Recent advances in the study of the bioactive conformation of taxol.  

PubMed

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. PMID:19360801

Sun, Liang; Simmerling, Carlos; Ojima, Iwao

2009-05-01

129

Peptide-conjugated biodegradable nanoparticles as a carrier to target paclitaxel to tumor neovasculature.  

PubMed

Antiangiogenic cancer therapy can be achieved through the targeted delivery of antiangiogenic agents to the endothelial cells of tumor neovasculature. In the present study, we developed a drug delivery system (DDS), nanoparticles conjugated with K237-(HTMYYHHYQHHL) peptides for tumor neovasculature targeting drug delivery. Paclitaxel, a chemotherapeutic agent with potent antiangiogenic activity, was used as a prototype drug. We synthesized the aldehyde poly(ethylene glycol)-poly(lactide) (aldehyde-PEG-PLA) block copolymer by ring opening polymerization. The nanoparticles loading paclitaxel (PTX-NP) were fabricated using the O/W emulsion and evaporation technique. K237 ligand, a peptide that can bind to the KDR receptors predominantly expressed on the surface of tumor neovasculature endothelial cells with high affinity and specificity and inhibit the VEGF-KDR angiogenic signal pathway, was conjugated to the aldehyde group of PEG chain using the N-terminal PEGylation technique. The K237 conjugated paclitaxel-loaded nanoparticles (K237-PTX-NP) had a hydrodynamic diameter of 150 nm. The K237 density on nanoparticle surface was 474 and the mean distance between two neighboring PEG chains linked to K237 peptide was 12 nm. The K237 conjugated nanoparticles could be significantly internalized by human umbilical vein endothelial cells (HUVEC) through the K237-KDR interaction, and this facilitated uptake led to the expected enhanced antiangiogenic activity shown by HUVEC proliferation, migration and tube formation compared to cells treated with the commercial formulation Taxol and PTX-NP. The long-circulating property and the K237 ligand of K237-PTX-NP warranted rapid, long-term, and accurate in vivo tumor neovasculature targeting, and thereafter the significant apoptosis of tumor neovasculature endothelial cells and necrosis of tumor tissues of MDA-MB-231 breast tumors implanted in female BLAB/c nude mice. This nanoparticulate DDS offers a new strategy for paclitaxel chemotherapy application and it could also be used to carry other chemotherapeutic drugs, genes, and proteins with antiangiogenic activity for antiangiogenic cancer therapy. PMID:20053444

Yu, De-Hong; Lu, Qin; Xie, Jing; Fang, Chao; Chen, Hong-Zhuan

2010-03-01

130

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. PMID:21646863

2011-01-01

131

Fate of paclitaxel lipid nanocapsules in intestinal mucus in view of their oral delivery  

PubMed Central

The bioavailability of paclitaxel (Ptx) has previously been improved via its encapsulation in lipid nanocapsules (LNCs). In this work, the interactions between LNCs and intestinal mucus are studied because they are viewed as an important barrier to successful oral delivery. The rheological properties of different batches of pig intestinal mucus were studied under different conditions (the effect of hydration and the presence of LNCs). Fluorescence resonance energy transfer (FRET) was used to study the stability of LNCs in mucus at 37°C for at least 3 hours. Diffusion through 223, 446, and 893 ?m mucus layers of 8.4, 16.8, and 42 ?g/mL Ptx formulated as Taxol® (Bristol-Myers Squibb, Rueil-Malmaison, France) or encapsulated in LNCs (Ptx-LNCs) were investigated. The effect of the size of the LNCs on their diffusion was also investigated (range, 25–110 nm in diameter). Mucus behaves as a non-Newtonian gel with rheofluidifying properties and a flow threshold. The viscous (G?) and elastic (G?) moduli and flow threshold of the two mucus batches varied with water content, but G? remained below G?. LNCs had no effect on mucus viscosity and flow threshold. The FRET efficiency remained at 78% after 3 hours. Because the destruction of the LNCs would lead to a FRET efficiency below 25%, these results suggest only a slight modification of LNCs after their contact with mucus. The diffusion of Taxol® and Ptx-LNCs in mucus decreases if the mucus layer is thicker. Interestingly, the apparent permeability across mucus is higher for Ptx-LNCs than for Taxol® for drug concentrations of 16.8 and 42 ?g/mL Ptx (P<0.05). The diffusion of Ptx-LNCs through mucus is not size-dependent. This study shows that LNCs are stable in mucus, do not change mucus rheological properties, and improve Ptx diffusion at low concentrations, thus making these systems good candidates for Ptx oral delivery. The study of the physicochemical interaction between the LNC surface and its diffusion in mucus is now envisioned. PMID:24235827

Groo, Anne-Claire; Saulnier, Patrick; Gimel, Jean-Christophe; Gravier, Julien; Ailhas, Caroline; Benoit, Jean-Pierre; Lagarce, Frederic

2013-01-01

132

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

133

Tumor targeting by conjugation of DHA to paclitaxel.  

PubMed

Targeting an anti-cancer drug to tumors should increase the Area Under the drug concentration-time Curve (AUC) in tumors while decreasing the AUC in normal cells and should therefore increase the therapeutic index of that drug. Anti-tumor drugs typically have half-lives far shorter than the cell cycle transit times of most tumor cells. Tumor targeting, with concomitant long tumor exposure times, will increase the proportion of cells that move into cycle when the drug concentration is high, which should result in more tumor cell killing. In an effort to test that hypothesis, we conjugated a natural fatty acid, docosahexaenoic acid (DHA), through an ester bond to the paclitaxel 2'-oxygen. The resulting paclitaxel fatty acid conjugate (DHA-paclitaxel) does not assemble microtubules and is non-toxic. In the M109 mouse tumor model, DHA-paclitaxel is less toxic than paclitaxel and cures 10/10 tumored animals, whereas paclitaxel cures 0/10. One explanation for the conjugate's greater therapeutic index is that the fatty acid alters the pharmacokinetics of the drug to increase its AUC in tumors and decrease its AUC in normal cells. To test that possibility, we compared the pharmacokinetics of DHA-paclitaxel with paclitaxel in CD2F1 mice bearing approximately 125 mg sc M109 tumors. The mice were injected at zero time with a bolus of either DHA-paclitaxel or paclitaxel formulated in 10% cremophor/10% ethanol/80% saline. Animals were sacrificed as a function of time out to 14 days. Tumors and plasma were frozen and stored. The concentrations of paclitaxel and DHA-paclitaxel were analyzed by LC/MS/MS. The results show that DHA targets paclitaxel to tumors: tumor AUCs are 61-fold higher for DHA-paclitaxel than for paclitaxel at equitoxic doses and eight-fold higher at equimolar doses. Likewise, at equi-toxic doses, the tumor AUCs of paclitaxel derived from i.v. DHA-paclitaxel are 6.1-fold higher than for paclitaxel derived from i.v. paclitaxel. The tumor concentration of paclitaxel derived from i.v. paclitaxel drops rapidly, so that by 16 h it has fallen to the same concentration (2.8 microM) as after an equi-toxic concentration of DHA-paclitaxel. In plasma, paclitaxel AUC after an MTD dose of DHA-paclitaxel is approximately 0.5% of DHA-paclitaxel AUC. Thus, the increase in tumor AUC and the limited plasma AUC of paclitaxel following DHA-paclitaxel administration are consistent with the increase in therapeutic index of DHA-paclitaxel relative to paclitaxel in the M109 mouse tumor model. A phase I clinical study has been completed at The Johns Hopkins Hospital to evaluate the safety of DHA-paclitaxel in patients with a variety of solid tumors. Twenty-one patients have been treated to date. The recommended phase II dose is 1100 mg/m(2), which is equivalent to 4.6 times the maximum approved paclitaxel dose on a molar basis. No alopecia or significant peripheral neuropathy, nausea, or vomiting have been observed. Asymptomatic, transient neutropenia has been the primary side effect. Eleven of 22 evaluable phase I patients transitioned from progressive to stable disease, as assessed by follow-up CT. Significant quality of life improvements have been observed. Thus, DHA-paclitaxel is well tolerated in patients and cures tumors in mice by targeting drug to tumors. PMID:11489499

Bradley, M O; Swindell, C S; Anthony, F H; Witman, P A; Devanesan, P; Webb, N L; Baker, S D; Wolff, A C; Donehower, R C

2001-07-01

134

A cDNA clone for taxadiene synthase, the diterpene cyclase that catalyzes the committed step of taxol biosynthesis.  

PubMed

The committed step of taxol (paclitaxel) biosynthesis is catalyzed by taxa-4(5),11(12)-diene synthase, a diterpene cyclase responsible for transforming the ubiquitous isoprenoid intermediate geranylgeranyl diphosphate to the parent olefin with a taxane skeleton. To obtain the corresponding cDNA clone, a set of degenerate primers was constructed based on consensus sequences of related monoterpene, sesquiterpene, and diterpene cyclases. Two of these primers amplified a 83-base pair fragment that was cyclase-like in sequence and that was employed as a hybridization probe to screen a cDNA library constructed from poly(A)+ RNA extracted from Pacific yew (Taxus brevifolia) stems. Twelve independent clones with insert size in excess of 2 kilobase pairs were isolated and partially sequenced. One of these cDNA isolates was functionally expressed in Escherichia coli, yielding a protein that was catalytically active in converting geranylgeranyl diphosphate to a diterpene olefin that was confirmed to be taxa-4(5),11(12)-diene by combined capillary gas chromatography-mass spectrometry. The sequence specifies an open reading frame of 2586 nucleotides, and the complete deduced polypeptide, including a long presumptive plastidial targeting peptide, contains 862 amino acid residues and has a molecular weight of 98,303, compared with about 79,000 previously determined for the mature native enzyme. Sequence comparisons with monoterpene, sesquiterpene, and diterpene cyclases of plant origin indicate a significant degree of similarity between these enzymes; the taxadiene synthase most closely resembles (46% identity, 67% similarity) abietadiene synthase, a diterpene cyclase from grand fir. PMID:8621577

Wildung, M R; Croteau, R

1996-04-19

135

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

136

Structureactivity profiles of eleutherobin analogs and their cross-resistance in Taxol-resistant cell lines  

Microsoft Academic Search

Purpose: Eleutherobin, a natural product, is an antimitotic agent that promotes the polymerization of stable microtubules. Although\\u000a its mechanism of action is similar to that of Taxol, its structure is distinct. A structure-activity profile of synthetic\\u000a eleutherobin derivatives that have modifications at C3, C8 and C15 was undertaken to define the structural requirements for\\u000a microtubule stabilization and cross-resistance in Taxol-resistant

Hayley M. McDaid; Samit K. Bhattacharya; Xiao-Tao Chen; Lifeng He; Heng-Jia Shen; Clare E. Gutteridge; Susan Band Horwitz; Samuel J. Danishefsky

1999-01-01

137

Non-anti-mitotic concentrations of taxol reduce breast cancer cell invasiveness  

SciTech Connect

Taxol is widely used in breast cancer chemotherapy. Its effects are primarily attributed to its anti-mitotic activity. Microtubule perturbators also exert antimetastatic activities which cannot be explained solely by the inhibition of proliferation. Voltage-dependent sodium channels (Na{sub V}) are abnormally expressed in the highly metastatic breast cancer cell line MDA-MB-231 and not in MDA-MB-468 cell line. Inhibiting Na{sub V} activity with tetrodotoxin is responsible for an approximately 0.4-fold reduction of MDA-MB-231 cell invasiveness. In this study, we focused on the effect of a single, 2-h application of 10 nM taxol on the two cell lines MDA-MB-231 and MDA-MB-468. At this concentration, taxol had no effect on proliferation after 7 days and on migration in any cell line. However it led to a 40% reduction of transwell invasion of MDA-MB-231 cells. There was no additive effect when taxol and tetrodotoxin were simultaneously applied. Na{sub V} activity, as assessed by patch-clamp, indicates that it was changed by taxol pre-treatment. We conclude that taxol can exert anti-tumoral activities, in cells expressing Na{sub V}, at low doses that have no effect on cell proliferation. This effect might be due to a modulation of signalling pathways involving sodium channels.

Tran, Truong-An; Gillet, Ludovic; Roger, Sebastien; Besson, Pierre [Inserm, U921, 37000 Tours (France); Universite Francois-Rabelais, 37000 Tours (France); White, Edward [Institute of Membrane and Systems Biology, University of Leeds, LS2 9JT LEEDS (United Kingdom); Le Guennec, Jean-Yves [Inserm, U921, 37000 Tours (France); Universite Francois-Rabelais, 37000 Tours (France)], E-mail: Jean-Yves.LeGuennec@Univ-Tours.Fr

2009-02-06

138

Herbal Medicine Goshajinkigan Prevents Paclitaxel-Induced Mechanical Allodynia without Impairing Antitumor Activity of Paclitaxel  

PubMed Central

Chemotherapy-induced peripheral neuropathy is a major dose-limiting side effect of commonly used chemotherapeutic agents. However, there are no effective strategies to treat the neuropathy. We examined whether Goshajinkigan, a herbal medicine, would prevent paclitaxel-induced allodynia without affecting the anticancer action in mice. Murine breast cancer 4T1 cells were inoculated into the mammary fat pad. Paclitaxel (10 and 20?mg/kg, intraperitoneal, alternate day from day 7 postinoculation) inhibited the tumor growth, and Goshajinkigan (1?g/kg, oral, daily from day 2 postinoculation) did not affect the antitumor action of paclitaxel. Mechanical allodynia developed in the inoculated region due to tumor growth and in the hind paw due to paclitaxel-induced neuropathy. Paclitaxel-induced allodynia was markedly prevented by Goshajinkigan, although tumor-associated allodynia was not inhibited by Goshajinkigan. These results suggest that Goshajinkigan prevents paclitaxel-induced peripheral neuropathy without interfering with the anti-cancer action of paclitaxel. PMID:24198846

Bahar, Muh. Akbar; Andoh, Tsugunobu; Ogura, Keisuke; Hayakawa, Yoshihiro; Saiki, Ikuo; Kuraishi, Yasushi

2013-01-01

139

Paclitaxel loaded nano-aggregates based on pH sensitive polyaspartamide amphiphilic graft copolymers.  

PubMed

Polyaspartamide (PASPAM) derivatives grafted with 1-(3-aminopropyl)imidazole (API), O-(2-aminoethyl)-O'-methylpolyethylene glycol (MPEG), and octadecylamine (C18) groups were synthesized and their pH-sensitive structure and Paclitaxel (PTX) load/release properties were investigated. C18/MPEG/API-g-PASPAMs systems synthesized showed a strong pH-dependent phase transition behavior near pH 6.7. Large amount of PTX up to 60-75%, depending on polymer composition, was possibly loaded into the C18/MPEG/API-g-PASPAMs nano-aggregates using a solvent-free protocol. Its pH dependent release pattern was affected correspondingly by the phase transition behavior associated with the composition of graft substituents. The pure C18/MPEG/API-g-PASPAMs systems did not show cell toxicity but the PTX-loaded copolymer systems showed a similar cell toxicity to a Taxol-type PTX. From the in vivo animal study, PTX-loaded nano-aggregates showed the much improved inhibition effect on tumor growth compared to the conventional PTX formulation. PMID:22226879

Seo, Kwangwon; Chung, Seung Woo; Byun, Youngro; Kim, Dukjoon

2012-03-15

140

A3 adenosine receptor agonist prevents the development of paclitaxel-induced neuropathic pain by modulating spinal glial-restricted redox-dependent signaling pathways.  

PubMed

Chemotherapy-induced peripheral neuropathy accompanied by chronic neuropathic pain is the major dose-limiting toxicity of several anticancer agents including the taxane paclitaxel (Taxol). A critical mechanism underlying paclitaxel-induced neuropathic pain is the increased production of peroxynitrite in spinal cord generated in response to activation of the superoxide-generating enzyme, NADPH oxidase. Peroxynitrite in turn contributes to the development of neuropathic pain by modulating several redox-dependent events in spinal cord. We recently reported that activation of the Gi/Gq-coupled A3 adenosine receptor (A3AR) with selective A3AR agonists (ie, IB-MECA) blocked the development of chemotherapy induced-neuropathic pain evoked by distinct agents, including paclitaxel, without interfering with anticancer effects. The mechanism or mechanisms of action underlying these beneficial effects has yet to be explored. We now demonstrate that IB-MECA attenuates the development of paclitaxel-induced neuropathic pain by inhibiting the activation of spinal NADPH oxidase and two downstream redox-dependent systems. The first relies on inhibition of the redox-sensitive transcription factor (NF?B) and mitogen activated protein kinases (ERK and p38) resulting in decreased production of neuroexcitatory/proinflammatory cytokines (TNF-?, IL-1?) and increased formation of the neuroprotective/anti-inflammatory IL-10. The second involves inhibition of redox-mediated posttranslational tyrosine nitration and modification (inactivation) of glia-restricted proteins known to play key roles in regulating synaptic glutamate homeostasis: the glutamate transporter GLT-1 and glutamine synthetase. Our results unravel a mechanistic link into biomolecular signaling pathways employed by A3AR activation in neuropathic pain while providing the foundation to consider use of A3AR agonists as therapeutic agents in patients with chemotherapy-induced peripheral neuropathy. PMID:25242567

Janes, Kali; Esposito, Emanuela; Doyle, Timothy; Cuzzocrea, Salvatore; Tosh, Dillip K; Jacobson, Kenneth A; Salvemini, Daniela

2014-12-01

141

Advancements in the understanding of Paclitaxel metabolism in tissue culture.  

PubMed

Paclitaxel is a potent chemotherapeutic agent approved in the treatment of a variety of cancers, and under evaluation for the treatment of Alzheimer's and heart disease. Originally isolated from Taxus brevifolia, this highly substituted ring diterpenoid belongs to a family of plant secondary metabolites known as taxoids. Paclitaxel is currently supplied through both a semi-synthetic process and plant cell culture. Taxus spp. cell culture offers the potential to produce large amounts of paclitaxel and related taxoids, although variability in accumulation and low yields represent key limitations. Thus, intense efforts have been put forth towards understanding Taxus spp. metabolism to increase paclitaxel accumulation in cell culture. While elicitation and environmental optimization have provided some success in increasing paclitaxel accumulation in vitro, understanding metabolism of paclitaxel on the molecular level is essential for process optimization. Utilizing direct and indirect molecular techniques, a further understanding of paclitaxel biosynthesis has been gained, though knowledge into other aspects of paclitaxel global metabolism, such as regulation, transport, and degradation is lacking. Taxus spp. cell cultures are highly heterogeneous, displaying significant cell-cell variability in growth and paclitaxel accumulation. Information gathered on culture subpopulations as well as putative transcriptional bottlenecks in paclitaxel biosynthesis, coupled with successful transformation of Taxus spp. will allow for the targeted metabolic engineering of Taxus spp. or other model organisms for paclitaxel accumulation to ensure future supply of this important pharmaceutical. PMID:17691991

Vongpaseuth, Kham; Roberts, Susan C

2007-08-01

142

An Italian cost-effectiveness analysis of paclitaxel albumin (nab-paclitaxel) versus conventional paclitaxel for metastatic breast cancer patients: the COSTANza study  

PubMed Central

Purpose Paclitaxel albumin (nab-paclitaxel) is a nanoparticle albumin-bound paclitaxel formulation aimed at increasing therapeutic index in metastatic breast cancer. When compared to conventional paclitaxel, nab-paclitaxel has a reported longer time to progression, higher response, lower incidence of neutropenia, no need for premedication, shorter time of administration, and in pretreated metastatic breast cancer patients, extended overall survival. This study investigates the cost-effectiveness of nab-paclitaxel versus conventional paclitaxel for pretreated metastatic breast cancer patients in Italy. Materials and methods A Markov model with progression-free, progressed, and dead states was developed to estimate costs, outcomes, and quality adjusted life years over 5 years from the Italian National Health Service viewpoint. Patients were assumed to receive nab-paclitaxel 260 mg/m2 three times weekly or conventional paclitaxel 175 mg/m2 three times weekly. Data on health care resource consumption was collected from a convenience sample of five Italian centers. Resources were valued at Euro (€) 2011. Published utility weights were applied to health states to estimate the impact of response, disease progression, and adverse events on quality adjusted life years. Three sensitivity analyses tested the robustness of the base case incremental cost-effectiveness ratio (ICER). Results and conclusion Compared to conventional paclitaxel, nab-paclitaxel gains an extra 0.165 quality adjusted life years (0.265 life years saved) and incurs additional costs of €2506 per patient treated. This translates to an ICER of €15,189 (95% confidence interval: €11,891–€28,415). One-way sensitivity analysis underscores that ICER for nab-paclitaxel remains stable despite varying taxanes cost. Threshold analysis shows that ICER for nab-paclitaxel exceeds €40,000 only if cost per mg of conventional paclitaxel is set to zero. Probabilistic sensitivity analysis highlights that nab-paclitaxel has a 0.99 probability to be cost-effective for a threshold value of €40,000 and is the optimal alternative from a threshold value of €16,316 onwards. Based on these findings, nab-paclitaxel can be considered highly cost-effective when compared to the acceptability range for ICER proposed by the Italian Health Economics Association (€25,000–€40,000). PMID:23610525

Lazzaro, Carlo; Bordonaro, Roberto; Cognetti, Francesco; Fabi, Alessandra; De Placido, Sabino; Arpino, Grazia; Marchetti, Paolo; Botticelli, Andrea; Pronzato, Paolo; Martelli, Elisa

2013-01-01

143

Promotion of tubulin assembly by poorly soluble taxol analogs.  

PubMed

Promotion or inhibition of tubulin assembly into microtubules is the standard in vitro assay for evaluating potential antimicrotubule agents. Many agents to be tested are poorly soluble in aqueous solution and require a cosolvent such as dimethyl sulfoxide (DMSO). However, DMSO itself can promote tubulin assembly, and its inclusion in assays for compounds that induce tubulin assembly complicates interpretation of the results. Substituting GDP for GTP in the exchangeable nucleotide binding site of tubulin produces a less active form of the protein, tubulin-GDP. Here it is shown that tubulin-GDP can be assembled into normal microtubules in DMSO concentrations up to 15% (v/v), and polymerization assays performed under these conditions can be compared with assays run under more standard conditions. Assays for measuring the effective concentration of a ligand for promotion of tubulin assembly (EC(50)), measuring the concentration for inhibition of tubulin assembly (IC(50)) by a colchicine site ligand, and measuring tubulin critical concentrations in the presence of poorly soluble taxol derivatives are illustrated. PMID:17097592

Sharma, Shubhada; Ganesh, Thota; Kingston, David G I; Bane, Susan

2007-01-01

144

Estrogen receptor expression and sensitivity to paclitaxel in breast cancer.  

PubMed

A retrospective analysis of CALGB trial 9344 suggested paclitaxel administration following cyclophosphamide and doxorubicin adjuvant chemotherapy is most beneficial for patients with ERalpha negative (ERalpha-) breast cancer. Since the cytotoxic effects of paclitaxel are cell cycle dependent, we postulated that the relationship between ERalpha and the effectiveness of adjuvant paclitaxel reflects the observation that ERalpha positive (ERalpha+) breast cancers proliferate more slowly than ERalpha- breast cancers. Three in vitro models (MCF-7, T47D and ZR-75) were examined to compare growth rates and paclitaxel-induced apoptosis in ERalpha+ and ERalpha- clones of the same, originally ERalpha+ cell line. For the T47D and ZR-75 cell lines, loss of ERalpha was associated with a decrease in doubling time and an increase in paclitaxel sensitivity. However, when cell culture conditions were altered to achieve equivalent cell proliferation rates, no difference in paclitaxel sensitivity was observed. Similarly, an ERalpha- clone of MCF-7 cells that did not exhibit an enhanced growth rate compared to its ERalpha+ counterpart also did not show increased paclitaxel sensitivity. The combined apoptotic effects of tamoxifen and paclitaxel on MCF-7 cells were not synergistic or even clearly additive. In these in vitro models, the effectiveness of paclitaxel correlated more closely with growth rate than ERalpha expression. These data suggest that measurements of tumor proliferation may provide more accurate predictive markers for the benefits of adjuvant paclitaxel than ERalpha analysis. PMID:15020841

Dougherty, Michele K; Schumaker, Lisa M; Jordan, V Craig; Welshons, Wade V; Curran, Edward M; Ellis, Matthew J; El-Ashry, Dorraya

2004-05-01

145

Taxol-resistant epithelial ovarian tumors are associated with altered expression of specific beta-tubulin isotypes.  

PubMed Central

The treatment of advanced ovarian cancer with taxol is hindered by the development of drug resistance. The cellular target for taxol is the microtubule that is stabilized by the drug. Taxol preferentially binds to the beta subunit of tubulin of which there are six distinct isotypes in mammalian cells. We have used highly specific oligonucleotides and polymerase chain reaction to analyze expression of all six beta-tubulin genes. Human lung cancer cells (A549) were selected in 12 and 24 nM taxol resulting in cell lines that were 9- and 17-fold resistant, respectively. These cells displayed an altered ratio of classes I, II, III, and IVa beta-tubulin isotypes. Ovarian tumors, seven untreated primary and four taxol- resistant tumor-bearing ascites, displayed significant increases (P < 0.005) in classes I (3.6-fold), III (4.4-fold), and IVa (7.6-fold) isotypes in the taxol-resistant samples as compared with untreated primary ovarian tumors. The increased expression appears to be related to the resistance phenotype, as the basal levels of the class III and IVa isotypes in the untreated tumors were extremely low. This is the first report of altered expression of specific beta-tubulin genes in taxol-resistant ovarian tumors and we propose that the latter may play a role in clinical resistance to taxol. PMID:9276747

Kavallaris, M; Kuo, D Y; Burkhart, C A; Regl, D L; Norris, M D; Haber, M; Horwitz, S B

1997-01-01

146

Supercritical extraction and HPLC analysis of taxol from Taxus brevifolia using nitrous oxide and nitrous oxide + ethanol mixtures  

Microsoft Academic Search

Taxol is an alkaloid which has been found to be exceptionally promising in the treatment of ovarian cancer. The major current sources of the drug are yew species which are in limited supply. As a result, there is a need for improved separation processes to effectively remove the drug from its natural sources. In this study, the separation of taxol

Vishnu Vandana; Amyn S. Teja; Leon H. Zalkow

1996-01-01

147

Taxol production and taxadiene synthase activity in Taxus canadensis cell suspension cultures.  

PubMed

The cyclization of geranylgeranyl diphosphate to taxa-4(5),11(12)-diene represents the first committed, and a slow, step in the complex biosynthetic pathway leading to the anticancer drug Taxol. The cyclization enzyme, taxadiene synthase, has been previously purified from Pacific yew (Taxus brevifolia) stem and characterized, and the corresponding cDNA has been isolated. To better assess the role of taxadiene synthase in the control of pathway flux in Canadian yew (T. canadensis) cells, a reliable system for production of Taxol in suspension culture, the enzyme from this source was isolated and shown to be chromatographically, electrophoretically, and kinetically identical to that of T. brevifolia stem. Results from the analysis of enzyme activity levels during the time course of Taxol accumulation in developing cell cultures of T. canadensis indicate that rate-limiting transformations lay farther down the pathway than the cyclization step in this system. PMID:9016812

Hezari, M; Ketchum, R E; Gibson, D M; Croteau, R

1997-01-15

148

Downstream reactions and engineering in the microbially reconstituted pathway for Taxol.  

PubMed

Taxol (a trademarked product of Bristol-Myers Squibb) is a complex isoprenoid natural product which has displayed potent anticancer activity. Originally isolated from the Pacific yew tree (Taxus brevifolia), Taxol has been mass-produced through processes reliant on plant-derived biosynthesis. Recently, there have been alternative efforts to reconstitute the biosynthetic process through technically convenient microbial hosts, which offer unmatched growth kinetics and engineering potential. Such an approach is made challenging by the need to successfully introduce the significantly foreign enzymatic steps responsible for eventual biosynthesis. Doing so, however, offers the potential to engineer more efficient and economical production processes and the opportunity to design and produce tailored analog compounds with enhanced properties. This mini review will specifically focus on heterologous biosynthesis as it applies to Taxol with an emphasis on the challenges associated with introducing and reconstituting the downstream reaction steps needed for final bioactivity. PMID:22460591

Jiang, Ming; Stephanopoulos, Gregory; Pfeifer, Blaine A

2012-05-01

149

Studies directed toward the synthesis of the A-ring of taxol  

SciTech Connect

Taxol 1, a novel anticancer agent, isolated from Taxus brevifolia, is a member of the class of taxane diterpenes. Since its isolation and characterization many groups around the world using varied approaches have made significant contributions toward the assembly of the taxane framework and ultimately to taxol itself. The focus of this investigation was directed towards making a fully functionalized A-ring synthon of taxol. Toward this end three approaches were explored. These approaches to the A-ring involve a Robinson annulation, an alkoxide accelerated vinylcyclobutane to cyclohexenol rearrangement and acid catalyzed electrophilic cyclization of geranyl acetate and its derivatives. Early difficulties with the alkoxide accelerated ring expansion approach resulted in it being aborted. The other two approaches led to interesting intermediates with the requisite number of carbon atoms and latent functionalities. However, later efforts to transform these intermediates to the targeted A-ring synthon (93), were futile.

Hamilton, P.M.

1992-01-01

150

Camptothecin and taxol: discovery to clinic--thirteenth Bruce F. Cain Memorial Award Lecture.  

PubMed

Camptothecin and taxol are secondary metabolites found, respectively, in the wood bark of Camptotheca acuminata, a native of China, and Taxus brevifolia, found in the northwest Pacific coastal region of the United States. The compounds were isolated guided by bioassay on various extracts and chromatographic fractions. Their unique and hitherto unknown structures were elucidated by nuclear magnetic resonance, mass spectrometry, and X-ray analysis. Both compounds have unique mechanisms of antitumor activity; camptothecin uniquely inhibits an enzyme, topoisomerase I, involved in DNA replication. Taxol binds to a protein, tubulin, thus inhibiting cell division. Taxol has been called the best new anticancer agent developed from natural products, showing particular efficacy against ovarian cancer. Camptothecin and analogues singly or combined with cisplatin show efficacy against solid tumors, breast, lung, and colorectal, which hitherto have been unaffected by most cancer chemotherapeutic agents. PMID:7850785

Wall, M E; Wani, M C

1995-02-15

151

Improved taxol yield by aromatic carboxylic acid and amino acid feeding to cell cultures of taxus cuspidata.  

PubMed

Cell culture of Taxus cuspidata represents an alternative to whole plant extraction as a source of taxol and related taxanes. Feeding phenylalanine to callus cultures was previously shown to result in increased taxol yields, probably due to the involvement of this amino acid as a precursor for the N-benzoylphenylisoserine side chain of taxol. Inthis study, we have examined the effect of various concentrations of phenylalanine, benzoic acid, N-benzoylglycine, serine, glycine, alanine, and 3-amino-3-phenyl-propionic acid on taxol accumulation in 2-year-old cell suspensions of Taxus cuspidata, cell line FCL1F, and in developing callus cultures of T. cuspidata. All compounds tested were included in media at stationary phase (suspensions) or after the period of fastest growth (calli). Alanine and 3-amino-3-phenyl-propionicacid were tested only in callus cultures and did not affect taxol accumulation. Significant increases or trends toward increases in taxol accumulationin callus and suspensions were observed in the presence of phenylalanine, benzoic acid, N-benzoylglycine, serine, and glycine. The greatest increases in taxol accumulation were observed in the presence of various concentrations of phenylalanine (1 mM for callus; 0.05, 0.1, and 0.2 mM for suspensions) and benzoic acid (0.2 and 1 mM for callus and 0.05, 0.1, and 0.2 mM for suspensions). Increases in taxol yields of cell suspensions in the presence of the most effective precursors brought taxol amounts at stationary phase from 2 mug . g(-1) to approximately 10 mug . g(-1) of the extracted dry weight. The results are discussed in termsof possible implications to taxol biosynthesis and in terms of practical applications to large-scale cell culture systems for the production ofthis drug. (c) 1994 John Wiley & Sons, Inc. PMID:18618915

Fett-Neto, A G; Melanson, S J; Nicholson, S A; Pennington, J J; Dicosmo, F

1994-10-01

152

Current status of paclitaxel in the treatment of breast cancer  

Microsoft Academic Search

Paclitaxel is a highly active single agent as therapy for previously untreated as well as doxorubicin-refractory metastatic breast cancer, with associated response rates of 62% and 20–48%, respectively. Complete responses with paclitaxel occur chiefly in breast cancer patients whose metastatic disease has not been previously treated with chemotherapy. Early data suggest a possible dose-response relationship for paclitaxel in metastatic breast

Joyce A. O'Shaughnessy; Kenneth H. Cowan

1995-01-01

153

Improved Taxol production by combination of inducing factors in suspension cell culture of Taxus baccata.  

PubMed

To date enormous attempts have been devoted to improve Taxol production exploiting various methodologies from bioprocess engineering to biotechnological and synthetic approaches. We have developed a 2-stage suspension cell culture of Taxus baccata L. using modified B5 medium in order to improve cell growth as well as productivity. After callus induction and cell line selection, B5 medium was supplemented with vanadyl sulfate (0.1 mg/l), silver nitrate (0.3 mg/l) and cobalt chloride (0.25 mg/l) at the first day of stage I culture to maximize cell growth. This medium was further supplemented with sucrose (1%) and ammonium citrate (50 mg/l) on day 10 and sucrose (1%) and phenylalanine (0.1 mM) on day 20 (i.e., biomass growth medium). At stage II (day 25), two different concentrations of several elicitors such as methyl jasmonate (10 or 20 mg/l), salicylic acid (50 or 100 mg/l) and fungal elicitor (25 or 50 mg/l) were added to the biomass growth medium with the aim of improving cellular productivity. For morphological analysis, microscopic inspection was carried out during cultivation. Cell-associated and extracellular amount of Taxol were detected and measured using HPLC methodology. At stage I, overall Taxol amount of biomass growth medium was 13.75 mg/l (i.e., 5.6-fold higher than that of untreated B5 control). At stage II, treated cells with methyl jasmonate (10 mg/l), salicylic acid (100 mg/l) and fungal elicitor (25 mg/l) produced the highest amount of Taxol (39.5 mg/l), which is 16-fold higher than that of untreated B5 control (2.45 mg/l). Microscopic analyses of Taxus cells in suspension cultures showed various positional auto-fluorescence showing direct correlation with Taxol production. Our studies revealed that intervallic supplementation of B5 medium with combination of biomass growth factors at stage I and mixture of elicitors at stage II could significantly increase Taxol production. Thus, we suggest that the exploitation of this methodology may improve the production of Taxol since demands for Taxol pharmaceuticals are increasingly growing and resource paucities have limited its direct harvesting from Taxus trees. PMID:16378737

Khosroushahi, A Yari; Valizadeh, M; Ghasempour, A; Khosrowshahli, M; Naghdibadi, H; Dadpour, M R; Omidi, Y

2006-03-01

154

Experimental design towards an optimal lipid nanosystem: a new opportunity for paclitaxel-based therapeutics.  

PubMed

Lipid based nanoparticles represent a class of nanocarriers that have caused great expectation, particularly due to their suitability to incorporate BCS class II and IV drugs. The use of solid lipid nanoparticles (SLNs) as a nanocarrier for antineoplastic agents has been underexplored when compared to the encapsulation of the same agents in polymeric particles. The preparation and efficacy assessment of a SLN platform as drug delivery carrier for anticancer agents, herein proposed as a strategy to find innovative formulations, could dramatically improve the outcome of cancer therapy. Considering these lipid nanoparticles, despite the great amount of insights described in the literature, it seems that improving their manufacturability could be the missing step to convert this system into a drug product. A way to circumvent that problem would be to select a preparation method that could take advantage of the pharmaceutical industry installed capabilities, thus speeding-up the scale-up translational steps while maintaining both regulatory compliance and flexibility. The High Pressure Homogenization (HPH) has proved to be a reliable process for SLN preparation. However, the use of the high-shear mixer, a well established process to manufacture coarse dispersions at industrial scale, has still not been fully explored to prepare SLN. In this study, we explore the possibility of using the hot emulsification/solidification method to prepare SLN's that complies with the current pharmaceutical quality requirements. Thus, a high-shear based process that consistently accomplishes performance requirements was optimized in order to standardize the nanocarrier production following the identification of some process and formulation critical parameters. A hydrophobic drug, Paclitaxel (Ptx) was successfully incorporated using the proposed developed method. The particles physicochemical characteristics changes caused by the drug entrapment as well as the particles stability were also evaluated. In addition the ability of SLN to travel across biological barriers due to its matrix lipid nature was explored upon comparing the efficacy of the drug loaded SLN with the conventional marketed drug product (Taxol®). The cellular uptake studies showed that the developed Ptx loaded SLN were in fact internalized and demonstrated higher efficacy in the cancer cells death process than Taxol. The experimental data demonstrated that the hot homogenization technique using a high-shear mechanical homogenizer allows the preparation of suitable size (around 150 nm) SLN. Overall, the results obtained can be particularly impactful in the forthcoming SLN research. PMID:23528739

Videira, Mafalda A; Arranja, Alexandra G; Gouveia, Luís F

2013-05-13

155

Antitumor properties of taxol in combination with cyclooxygenase-1 and cyclooxygenase-2 selective inhibitors on ovarian tumor growth in vivo.  

PubMed

The present study was designed to investigate whether taxol in combination with cyclooxygenase (COX) inhibitors could be superior on inhibitory effect of ovarian cancer growth than taxol alone as drug therapy of mice implanted with human ovarian carcinoma cell line SKOV-3. The animals were treated with 100 mg/ kg celecoxib (a COX-2 selective inhibitor) alone or in combination with 3 mg/kg SC-560 (a COX-1 selective inhibitor) by gavage twice a day, 20mg/kg taxol alone by intraperitoneal (IP) once a week or in combination with celecoxib, or SC-560/celecoxib/taxol for 3 weeks. To test the mechanism of the combination treatment, the index of cell proliferation, expression of cyclin D1, and microvessel density (MVD) in tumor tissues were determined by immunohistochemistry and the index of apoptotic cells by the terminal-deoxynucleotidyl-transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL) method. Mean tumor volume in the SC-560/celecoxib/taxol group was first significantly lower than control at day 14 (p < 0.05). In the SC-560/celecoxib/taxol group, the index of cell proliferation and apoptosis and quantification of cyclin D1-postive cells were 6.93%, 69.62%, and 19.14%, respectively, which are statistically significant compared with those of the control group (29.85%, p < 0.001; 32.81% and 36.99%, both p < 0.05). Statistical significance on MVD was observed between the SC-560/celecoxib/taxol (39.57 +/- 4.98) and the control (73.2 +/- 1.96) group (p < 0.001). Our results suggest that the combined antitumor efficacy of taxol and COX inhibitors may be superior to taxol alone as drug therapy against ovarian cancer in mice, and that synergism of the combination treatment in part may be mediated through accelerated apoptosis and suppression of cell proliferation and angiogenesis. PMID:23193911

Li, Wei; Zhai, Lingyun; Tang, Yunxian; Cai, Jiahui; Liu, Meilin; Zhang, Jun

2012-01-01

156

Novel molecules that interact with microtubules and have functional activity similar to Taxol  

Microsoft Academic Search

Taxol™ is an antitumor drug approved by the FDA for the treatment of ovarian, breast and non-small-cell lung carcinomas. Originally isolated from the bark of the Pacific yew, Taxus brevifolia, it was the first natural product described that stabilized microtubules. In the past five years, a group of novel natural products, including the epothilones, discodermolide, eleutherobin, sarcodictyins and the laulimalides,

Lifeng He; George A Orr; Susan Band Horwitz

2001-01-01

157

Subcutaneous study on the controlled release of Etanidazole and Taxol for the treatment of Glioma  

E-print Network

BALB/c nude mice 6 weeks old were inoculated with glioma C6 cell-line and the efficacy of the different amount of Etanidazole-discs and Taxol-microspheres was investigated. Poly (D,L-lactic-co-glycolic acid) (PLGA) was ...

Naraharisetti, Pavan Kumar

158

Improved Taxol production by combination of inducing factors in suspension cell culture of Taxus baccata  

Microsoft Academic Search

To date enormous attempts have been devoted to improve Taxol production exploiting various methodologies from bioprocess engineering to biotechnological and synthetic approaches. We have developed a 2-stage suspension cell culture of Taxus baccata L. using modified B5 medium in order to improve cell growth as well as productivity. After callus induction and cell line selection, B5 medium was supplemented with

A. Yari Khosroushahi; M. Valizadeh; A. Ghasempour; M. Khosrowshahli; H. Naghdibadi; M. R. Dadpour; Y. Omidi

2006-01-01

159

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,

160

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,

161

Paclitaxel and concurrent radiation in upper gastrointestinal cancers.  

PubMed

Effective locoregional treatments are needed for adenocarcinomas of the esophagus, stomach, and pancreas. Paclitaxel has been investigated as a radiation sensitizer for upper gastrointestinal malignancies. In esophageal cancer, the combination of low-dose weekly paclitaxel, platinum, and concurrent radiation therapy (RT) has substantial activity and is well tolerated. Regimens that add fluorouracil (5-FU) to paclitaxel and platinum or incorporate hyperfractionation radiation have a higher incidence of severe esophagitis. In gastric cancer, adjuvant concurrent paclitaxel, 5-FU, and radiation is being investigated in the cooperative group setting. In pancreatic cancer, paclitaxel may be a radiation sensitizer even to tumor cells that are resistant to paclitaxel as a single agent. The Radiation Therapy Oncology Group (RTOG) demonstrated a 43% 1-year survival with paclitaxel/RT for patients with locally advanced pancreatic cancer. This represented a 40% improvement in survival compared to the previous RTOG 92-09 study of 5-FU-based chemoradiation. Ongoing trials in pancreatic cancer are investigating the addition of gemcitabine to paclitaxel and radiation and incorporating molecular targeting agents. PMID:14735693

Constantinou, Maria; Tsai, James Y; Safran, Howard

2003-01-01

162

A Randomized Clinical Trial of Cisplatin\\/Paclitaxel Versus Carboplatin\\/Paclitaxel as First-Line Treatment of Ovarian Cancer  

Microsoft Academic Search

Background: Despite considerable improvement in the treat- ment of advanced ovarian cancer, the optimization of effi- cacy and tolerability remains an important issue. Therefore, we performed a randomized, phase III non-inferiority trial comparing paclitaxel plus cisplatin (PT) with paclitaxel plus carboplatin (TC) in patients with advanced ovarian cancer. Methods: A total of 798 patients with International Federa- tion of Gynecology

Hans-Joachim Luck; Werner Meier; Hans-Peter Adams; Volker Mobus; Serban Costa; Thomas Bauknecht; Barbara Richter; Matthias Warm; Willibald Schroder; Sigrid Olbricht; Ulrike Nitz; Christian Jackisch; Gunther Emons; Uwe Wagner; Walther Kuhn; Jacobus Pfisterer

2003-01-01

163

Characterization of the Taxol binding site on the microtubule. Identification of Arg(282) in beta-tubulin as the site of photoincorporation of a 7-benzophenone analogue of Taxol.  

PubMed

Photoaffinity labeling methods have allowed a definition of the sites of interaction between Taxol and its cellular target, the microtubule, specifically beta-tubulin. Our previous studies have indicated that [(3)H]3'-(p-azidobenzamido)Taxol photolabels the N-terminal 31 amino acids of beta-tubulin (Rao, S., Krauss, N. E., Heerding, J. M., Swindell, C. S., Ringel, I., Orr, G. A., and Horwitz, S. B. (1994) J. Biol. Chem. 269, 3132-3134) and [(3)H]2-(m-azidobenzoyl)Taxol photolabels a peptide containing amino acid residues 217-233 of beta-tubulin (Rao, S., Orr, G. A., Chaudhary, A. G., Kingston, D. G. I., and Horwitz, S. B. (1995) J. Biol. Chem. 270, 20235-20238). The site of photoincorporation of a third photoaffinity analogue of Taxol, [(3)H]7-(benzoyldihydrocinnamoyl) Taxol, has been determined. This analogue stabilizes microtubules polymerized in the presence of GTP, but in contrast to Taxol, does not by itself enhance the polymerization of tubulin to its polymer form. CNBr digestion of [(3)H]7-(benzoyldihydrocinnamoyl)Taxol-labeled tubulin, with further arginine-specific cleavage by clostripain resulted in the isolation of a peptide containing amino acid residues 277-293. Amino acid sequence analysis indicated that the photoaffinity analogue cross-links to Arg(282) in beta-tubulin. Advances made by electron crystallography in understanding the structure of the tubulin dimer have allowed us to visualize the three sites of photoincorporation by molecular modeling. There is good agreement between the binding site of Taxol in beta-tubulin as determined by photoaffinity labeling and electron crystallography. PMID:10608867

Rao, S; He, L; Chakravarty, S; Ojima, I; Orr, G A; Horwitz, S B

1999-12-31

164

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. PMID:23696703

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

2013-01-01

165

Characteristics of the combination paclitaxel plus doxorubicin in breast cancer cell lines analyzed with the ATP-cell viability assay.  

PubMed

Preliminary clinical data show promising activity regarding the combination of paclitaxel (Taxol) (TAX) and doxorubicin (Adriamycin) (ADR) in the treatment of breast cancer. This combination needs both further preclinical and clinical investigations to better understand the drug interaction, and to optimize the dose and schedule of these drugs. This study was done to evaluate the combination effect of TAX and ADR in three human breast cancer cell lines. The ATP-Cell-Viability Assay was used to evaluate the chemosensitivity profiles and to obtain dose response curves. For quantitation of synergism and antagonism the median-effect principle was applied and the corresponding combination index values were calculated. Drug synergism/antagonism was shown to be dose-related; synergism was enhanced at higher fractions affected. From this preclinical data, we have concluded that TAX-ADR is highly effective and partly synergistic in vitro. In spite of severe initial toxicities in early clinical trials in metastatic breast cancer patients, further clinical studies appear to be justified in order to define a tolerable dosage. PMID:7907234

Koechli, O R; Sevin, B U; Perras, J P; Chou, T C; Angioli, R; Steren, A; Untch, M; Averette, H E

1993-10-01

166

Tubulins in the primate retina: evidence that xanthophylls may be endogenous ligands for the paclitaxel-binding site.  

PubMed

The xanthophylls-lutein, zeaxanthin, and meso-zeaxanthin (L&Z)-are found in the central region of the primate retina, which is called the macula lutea (yellow spot). How they are anchored there and what their function is has been debated for over 50 years. Here, we present evidence that they may be bound to the paclitaxel (Taxol) binding site of the beta-tubulin subunit of microtubules and that a major function may be to modulate the dynamic instability of microtubules in the macula. Also, we compare nucleic acid and amino acid sequences of tubulins that are in human brain with those we have isolated from human-retina and monkey-macula cDNA libraries. In so doing, we suggest that in primates, class I beta-tubulin consists of at least two subtypes (beta(Ia) and beta(Ib)). Alignment analysis of the sequences of the genes for beta(Ia) and beta(Ib) indicates that the corresponding mRNAs may have other functions in addition to that of coding for proteins. Furthermore, we show that there are at least five different types of beta-tubulin in the macula lutea of rhesus monkey. PMID:11504633

Crabtree, D V; Ojima, I; Geng, X; Adler, A J

2001-08-01

167

Hypoxia counteracts taxol-induced apoptosis in MDA-MB-231 breast cancer cells: role of autophagy and JNK activation  

PubMed Central

Cancer cell resistance against chemotherapy is still a heavy burden to improve anticancer treatments. Autophagy activation and the development of hypoxic regions within the tumors are known to promote cancer cell resistance. Therefore, we sought to evaluate the role of autophagy and hypoxia on the taxol-induced apoptosis in MDA-MB-231 breast cancer cells. The results showed that taxol induced apoptosis after 16?h of incubation, and that hypoxia protected MDA-MB-231 cells from taxol-induced apoptosis. In parallel, taxol induced autophagy activation already after 2?h of incubation both under normoxia and hypoxia. Autophagy activation after taxol exposure was shown to be a protective mechanism against taxol-induced cell death both under normoxia and hypoxia. However, at longer incubation time, the autophagic process reached a saturation point under normoxia leading to cell death, whereas under hypoxia, autophagy flow still correctly took place allowing the cells to survive. Autophagy induction is induced after taxol exposure via mechanistic target of rapamycin (mTOR) inhibition, which is more important in cells exposed to hypoxia. Taxol also induced c-Jun N-terminal kinase (JNK) activation and phosphorylation of its substrates B-cell CLL/lymphoma 2 (Bcl2) and BCL2-like 1 (BclXL) under normoxia and hypoxia very early after taxol exposure. Bcl2 and BclXL phosphorylation was decreased more importantly under hypoxia after long incubation time. The role of JNK in autophagy and apoptosis induction was studied using siRNAs. The results showed that JNK activation promotes resistance against taxol-induced apoptosis under normoxia and hypoxia without being involved in induction of autophagy. In conclusion, the resistance against taxol-induced cell death observed under hypoxia can be explained by a more effective autophagic flow activated via the classical mTOR pathway and by a mechanism involving JNK, which could be dependent on Bcl2 and BclXL phosphorylation but independent of JNK-induced autophagy activation. PMID:23681233

Notte, A; Ninane, N; Arnould, T; Michiels, C

2013-01-01

168

Hypoxia counteracts taxol-induced apoptosis in MDA-MB-231 breast cancer cells: role of autophagy and JNK activation.  

PubMed

Cancer cell resistance against chemotherapy is still a heavy burden to improve anticancer treatments. Autophagy activation and the development of hypoxic regions within the tumors are known to promote cancer cell resistance. Therefore, we sought to evaluate the role of autophagy and hypoxia on the taxol-induced apoptosis in MDA-MB-231 breast cancer cells. The results showed that taxol induced apoptosis after 16 h of incubation, and that hypoxia protected MDA-MB-231 cells from taxol-induced apoptosis. In parallel, taxol induced autophagy activation already after 2 h of incubation both under normoxia and hypoxia. Autophagy activation after taxol exposure was shown to be a protective mechanism against taxol-induced cell death both under normoxia and hypoxia. However, at longer incubation time, the autophagic process reached a saturation point under normoxia leading to cell death, whereas under hypoxia, autophagy flow still correctly took place allowing the cells to survive. Autophagy induction is induced after taxol exposure via mechanistic target of rapamycin (mTOR) inhibition, which is more important in cells exposed to hypoxia. Taxol also induced c-Jun N-terminal kinase (JNK) activation and phosphorylation of its substrates B-cell CLL/lymphoma 2 (Bcl2) and BCL2-like 1 (BclXL) under normoxia and hypoxia very early after taxol exposure. Bcl2 and BclXL phosphorylation was decreased more importantly under hypoxia after long incubation time. The role of JNK in autophagy and apoptosis induction was studied using siRNAs. The results showed that JNK activation promotes resistance against taxol-induced apoptosis under normoxia and hypoxia without being involved in induction of autophagy. In conclusion, the resistance against taxol-induced cell death observed under hypoxia can be explained by a more effective autophagic flow activated via the classical mTOR pathway and by a mechanism involving JNK, which could be dependent on Bcl2 and BclXL phosphorylation but independent of JNK-induced autophagy activation. PMID:23681233

Notte, A; Ninane, N; Arnould, T; Michiels, C

2013-01-01

169

Delayed expression of apoptosis in human lymphoma cells undergoing low-dose taxol-induced mitotic stress  

Microsoft Academic Search

The links between low-dose range taxol-induced mitotic arrest and the subsequent engagement of apoptosis are important for identifying the routes to therapeutic action. Here we have investigated the timing of cell-cycle perturbation and cell death responses following continuous exposure to clinically relevant drug concentrations (1–20 nM). Following 8 h of exposure to taxol, the cell line DoHH2 (p53 wild type)

R Allman; R J Errington; P J Smith

2003-01-01

170

The search for a taxol-producing microorganism among the endophytic fungi of the Pacific yew, Taxus brevifolia.  

PubMed

Endophytic microbes associated with the Pacific yew tree, Taxus brevifolia, were examined as potential sources of the anticancer drug taxol [1], a secondary metabolite of the host organism. The first promising organism found was the novel fungus, Taxomyces andreanae, which was isolated from the inner bark of a yew tree growing in northwestern Montana. It appears to produce taxol and other taxanes in de novo fashion when grown in semi-synthetic liquid media. The presence of 1 in the fungal extract was confirmed by mass spectrometry, comparative chromatographic behavior with "yew" taxol, reactivity with taxol-specific monoclonal antibodies, and 9KB cytotoxicity studies. Both acetate-1-14C and phenylalanine UL-14C served as precursors of taxol-14C in fungal culture labeling studies, confirming the de novo synthesis of 1 by the fungus. Immunoassay techniques are currently being used to screen extracts of Taxomyces andreanae for new taxanes, and to determine if other endophytic fungi are taxol producers. PMID:7494141

Stierle, A; Strobel, G; Stierle, D; Grothaus, P; Bignami, G

1995-09-01

171

Effects of SC-560 in Combination with Cisplatin or Taxol on Angiogenesis in Human Ovarian Cancer Xenografts  

PubMed Central

This study was designed to evaluate the effect of cyclooxygenase-1 (COX-1) inhibitor, SC-560, combined with cisplatin or taxol, on angiogenesis in human ovarian cancer xenografts. Mice were treated with intraperitoneal (i.p.) injections of SC-560 6 mg/kg/day, i.p. injections of cisplatin 3 mg/kg every other day and i.p. injections of taxol 20 mg/kg once a week for 21 days. Vascular endothelial growth factor (VEGF) mRNA levels were detected by reverse transcription-polymerase chain reaction (RT-PCR); microvessel density (MVD) was determined by immunohistochemistry; and prostaglandin E2 (PGE2) levels were determined using ELISA. Expression levels of VEGF mRNA and MVD in treatment groups were inhibited significantly when compared with the control group (p < 0.05 for all), and SC-560 combined with cisplatin displayed a greater reduction in the expression of VEGF and MVD than SC-560 or cisplatin alone (p < 0.05). SC-560 combined with taxol showed a greater inhibition on VEGF mRNA expression than SC-560 or taxol alone (p < 0.05). The level of PGE2 in treatment groups was significantly reduced when compared with the control group (p < 0.01 for all). These findings may indicate that cisplatin or taxol supplemented by SC-560 in human ovarian cancer xenografts enhances the inhibition effect of cisplatin or taxol alone on angiogenesis. PMID:25342321

Li, Wei; Wan, Liang; Zhai, Ling-Yun; Wang, Jane

2014-01-01

172

Effects of SC-560 in Combination with Cisplatin or Taxol on Angiogenesis in Human Ovarian Cancer Xenografts.  

PubMed

This study was designed to evaluate the effect of cyclooxygenase-1 (COX-1) inhibitor, SC-560, combined with cisplatin or taxol, on angiogenesis in human ovarian cancer xenografts. Mice were treated with intraperitoneal (i.p.) injections of SC-560 6 mg/kg/day, i.p. injections of cisplatin 3 mg/kg every other day and i.p. injections of taxol 20 mg/kg once a week for 21 days. Vascular endothelial growth factor (VEGF) mRNA levels were detected by reverse transcription-polymerase chain reaction (RT-PCR); microvessel density (MVD) was determined by immunohistochemistry; and prostaglandin E2 (PGE2) levels were determined using ELISA. Expression levels of VEGF mRNA and MVD in treatment groups were inhibited significantly when compared with the control group (p < 0.05 for all), and SC-560 combined with cisplatin displayed a greater reduction in the expression of VEGF and MVD than SC-560 or cisplatin alone (p < 0.05). SC-560 combined with taxol showed a greater inhibition on VEGF mRNA expression than SC-560 or taxol alone (p < 0.05). The level of PGE2 in treatment groups was significantly reduced when compared with the control group (p < 0.01 for all). These findings may indicate that cisplatin or taxol supplemented by SC-560 in human ovarian cancer xenografts enhances the inhibition effect of cisplatin or taxol alone on angiogenesis. PMID:25342321

Li, Wei; Wan, Liang; Zhai, Ling-Yun; Wang, Jane

2014-01-01

173

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. PMID:22732474

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

2012-01-01

174

Novel molecules that interact with microtubules and have functional activity similar to Taxol.  

PubMed

Taxol is an antitumor drug approved by the FDA for the treatment of ovarian, breast and non-small-cell lung carcinomas. Originally isolated from the bark of the Pacific yew, Taxus brevifolia, it was the first natural product described that stabilized microtubules. In the past five years, a group of novel natural products, including the epothilones, discodermolide, eleutherobin, sarcodictyins and the laulimalides, all of which have biological activities similar to those of Taxol, has been discovered. In this review, we discuss each of these novel microtubule-stabilizing agents and the search for a common pharmacophore among them, taking into consideration recent advances in our understanding of the taxanes and tubulin. PMID:11700217

He, Lifeng; Orr, George A.; Horwitz, Susan Band

2001-11-15

175

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

176

Taxol Production and Taxadiene Synthase Activity in Taxus canadensisCell Suspension Cultures  

Microsoft Academic Search

The cyclization of geranylgeranyl diphosphate to taxa-4(5),11(12)-diene represents the first committed, and a slow, step in the complex biosynthetic pathway leading to the anticancer drug Taxol. The cyclization enzyme, taxadiene synthase, has been previously purified from Pacific yew (Taxus brevifolia) stem and characterized, and the corresponding cDNA has been isolated. To better assess the role of taxadiene synthase in the

Mehri Hezari; Raymond E. B. Ketchum; Donna M. Gibson; Rodney Croteau

1997-01-01

177

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

178

Effect of taxol from Pestalotiopsis mangiferae on A549 cells-In vitro study.  

PubMed

Pestalotiopsis mangiferae Coelomycete fungi were used to examine the production of taxol. The taxol isolated from this fungus is biologically active against cancer cell lines were investigated for its antiproliferative activity in human Non Small Cell Lung Cancer A549 cells. The results showed that the methylene chloride extraction of Pestalotiopsis mangiferae inhibited the proliferation of A 549 cells as measured by MTT and Trypan blue assay. Flow cytometric analysis showed that methylene chloride extraction of Pestalotiopsis mangiferae blocked cell cycle progression in G0/G1 phase. In addition fungal taxol induced A549 cell apoptosis as determined by propidium iodide staining. Further the percentage of LDH release was increased at increasing concentrations which is a measure of cell death. The levels of sialic acid levels and DNA, RNA and protein levels were decreased after treatment with methylene chloride extraction of Pestalotiopsis mangiferae. We suggests that methylene chloride extraction of Pestalotiopsis mangiferae might be considered for future therapeutic application with further studies against lung cancer. PMID:25206246

Kathiravan, Govindarajan; Sureban, Sripathi M

2009-12-01

179

Clinical trials and progress with paclitaxel in ovarian cancer.  

PubMed

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. PMID:21270965

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

2010-01-01

180

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. PMID:23346084

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

2012-01-01

181

Weekly paclitaxel infusion as salvage therapy in ovarian cancer.  

PubMed

The majority of women diagnosed with epithelial ovarian cancer will have persistent or recurrent disease after initial treatment. We evaluated response and toxicity in women with advanced stage disease given salvage paclitaxel as a low-dose, weekly infusion. We performed a retrospective review of 22 women with advanced stage epithelial ovarian (19 women) or primary peritoneal carcinoma (3 women) who had received low-dose, weekly paclitaxel salvage therapy. All women had refractory, persistent, or recurrent disease following first-line treatment with paclitaxel and platin chemotherapy. Response and toxicity were assessed. Measurable disease present on physical or radiologic exam and serum carbohydrate antigen-125 levels were used to assess disease response. Overall response rate to low-dose, weekly paclitaxel salvage therapy was 50% (27% complete, 23% partial). Median progression-free interval (PFI) in responders was 27 weeks (range, 14-68 weeks). Stabilization of disease occurred in an additional 27% of patients with a median PFI of 22 weeks (range, 15-89 weeks). No difference in response was detected between the 7 women with platin-sensitive disease and the 15 women with platin-resistant disease (P = 0.19). The median dose of paclitaxel was 80 mg/m2 (range, 60-80 mg/m2). During a total of 325 weeks of paclitaxel treatment (median per patient, 12 weeks; range, 6-49 weeks), 13 treatment delays occurred (hematologic indication, 9; nonhematologic indication, 4). No cases of grade 4 hematologic toxicity, sepsis, or worsening neuropathy were documented. Weekly paclitaxel infusion given as salvage therapy results in significant clinical response, even in women previously treated with paclitaxel. The regimen is well tolerated with no cases of grade 4 neutropenia or worsening neuropathy in our population. PMID:14628424

Boruta, David M; Fowler, Wesley C; Gehrig, Paola A; Boggess, John F; Walton, Leslie A; Van Le, Linda

2003-01-01

182

Paclitaxel Induces Apoptosis in AIDS-Related Kaposi's Sarcoma Cells  

PubMed Central

Paclitaxel is a microtubule stabilizing drug that causes dividing cells to arrest and then undergo apoptosis. It also has antiangiogenic activity because it alters cytoskeletal structure, affecting migration and invasion. Paclitaxel is an effective treatment for AIDS-related Kaposi’s sarcoma (KS). KS is a tumor in which there is marked proliferation of endothelial cells in addition to the tumor cells, which themselves share many markers with activated (proliferating) endothelial cells.We sought to determine the mechanism by which paclitaxel exerts its anti-KS tumor effects. In vitro, KS cells are very sensitive to paclitaxel, with half-maximal growth inhibition observed at 0.8 nM. Inhibition of migration of KS cells was also observed at nanomolar concentrations of the drug. Paclitaxel induced cell cycle arrest with an accumulation of cells in sub-G1.This was accompanied in vitro by various events typical of apoptosis: phosphorylation of two anti-apoptotic proteins Bcl-2 and Bcl-xL , release of cytochrome c into the cytoplasm, cleavage and activation of caspase-3. In vitro results were borne out by studies of KS tumor xenografts in nude mice. Paclitaxel (10 mg/kg) inhibited tumor growth by 75% over 21 days. Histological examination of the tumors revealed a decrease in proliferative index, a decrease in the number of mitotic figures and an increase in apoptotic cells compared to tumors from untreated mice. PMID:18521433

Cai, Jie; Zheng, Tong; Masood, Rizwan; Smith, D. Lynne; Hinton, David R.; Kim, Caryn Nae; Fang, Guofu; Bhalla, Kapil

2000-01-01

183

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

184

Idiotypic Mimicry and the Assembly of a Supramolecular Structure: An Anti-Idiotypic Antibody that Mimics Taxol in its Tubulin-Microtubule Interactions  

Microsoft Academic Search

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

Jyh-Gang Leu; Bi-Xing Chen; Andrew W. Diamanduros; Bernard F. Erlanger

1994-01-01

185

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

186

Modulation of human mammary cell sensitivity to paclitaxel by new quinoline sulfonamides.  

PubMed

Sulfonamide derivatives of chloroquine and primaquine were synthesised and evaluated against both paclitaxel-sensitive and paclitaxel-resistant mammarian cancer cell lines. All derivatives exhibited at least 96% MDR reversal activity when co-administered with paclitaxel at 5 microM. The best compound, a chloroquine derivative, exhibited 99% MDR reversal activity when co-administered with paclitaxel at 1 microM. Molecular modelling studies reveal that these derivatives share a common pharmacophore with taxane MDR reversal agents. PMID:11549446

Chibale, K; Ojima, I; Haupt, H; Geng, X; Pera, P; Bernacki, R J

2001-09-17

187

Taxol effect: bizarre mitotic figures (abnormal spindle asters) in a malignant peritoneal effusion: report of a case.  

PubMed

Taxol (Paclitaxol) is a diterpenoid taxane derivative found in the bark and needles of the Western yew, Taxus brevifolia, indigenous to the old growth forests of the Pacific Northwest. As compared with other antineoplastic agents (vinca alkaloids and colchicine) that enhance microtubule disassembly, taxol promotes microtubule polymerization. In interphase cells, abnormal microtubular bundles or arrays are seen. In mitotic cells, abnormal spindle asters form. Such morphologic changes have been described frequently in cell culture systems and in in vitro systems using fresh tumor tissue. To our knowledge, these changes have not been described in a peritoneal effusion specimen from a patient with stage III ovarian cancer treated with taxol. In addition, the mitotic stabilization produced interpretative difficulties in evaluating the peritoneal fluid because a vast majority of the presumed malignant cells were in mitosis and, hence, not evaluable by ordinary cytologic criteria. PMID:9285194

Jordan, C D; Wells, W A

1997-09-01

188

Paclitaxel nanoparticle inhibits growth of ovarian cancer xenografts and enhances lymphatic targeting  

Microsoft Academic Search

Objectives: Ovarian cancer has the highest mortality of all the gynecologic cancers. The antitumor agent paclitaxel has been proved to be efficient in the treatment of ovarian cancer. Our study is to develop a polymeric drug delivery system for paclitaxel and determine whether paclitaxel nanoparticle can inhibit growth of ovarian carcinoma xenografts in Fisher344 (F344) rats by intraperitoneal administration. The

Hongxia Lu; Bin Li; Yu Kang; Wei Jiang; Qian Huang; Qinghua Chen; Limin Li; Congjian Xu

2007-01-01

189

RNA interference (RNAi) screening approach identifies agents that enhance paclitaxel activity in breast cancer cells  

Microsoft Academic Search

ABSTRACT: INTRODUCTION: Paclitaxel is a widely used drug in the treatment of patients with locally advanced and metastatic breast cancer. However, only a small portion of patients have a complete response to paclitaxel-based chemotherapy, and many patients are resistant. Strategies that increase sensitivity and limit resistance to paclitaxel would be of clinical use, especially for patients with triple-negative breast cancer

Joshua A Bauer; Fei Ye; Clayton B Marshall; Brian D Lehmann; Christopher S Pendleton; Yu Shyr; Carlos L Arteaga; Jennifer A Pietenpol

2010-01-01

190

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

PubMed

Survivin is an essential chromosomal passenger protein whose function remains unclear. Here, we have used RNA interference to specifically repress Survivin in cultured HeLa cells. Immunoblot analysis showed that Survivin was no longer detectable in cultures 60 hours after transfection with Survivin-specific siRNA. Live cell analysis showed that many Survivin-depleted cells were delayed in mitosis, and immunofluorescence analysis of fixed specimens revealed that Survivin-depleted cells accumulated in prometaphase with misaligned chromosomes. The chromosomal passenger proteins, INCENP and Aurora-B, which can interact directly with Survivin, were absent from the centromeres of Survivin-depleted cells. These data contribute to the emerging picture that Survivin operates together with INCENP and Aurora-B to perform its mitotic duties. Some Survivin-depleted cells eventually exited mitosis without completing cytokinesis. This resulted in a 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 presence of either taxol or nocodazole. Our data reveal that Survivin is not required for the spindle assembly checkpoint when it is activated by the loss of microtubules. However, Survivin is required for the maintenance of the checkpoint when it is activated by taxol, which is generally thought to cause a loss of spindle tension. PMID:12783991

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

2003-07-15

191

Design and Characterization of PEG-Derivatized Vitamin E as a Nanomicellar Formulation for Delivery of Paclitaxel  

PubMed Central

Various PEG-Vitamin E conjugates including D-alpha-tocopheryl polyethylene glycol succinate 1000 (TPGS) have been extensively studied as a nonionic surfactant in various drug delivery systems. However, limited information is available about the structure-activity relationship of PEG-Vitamin E conjugates as a micellar formulation for paclitaxel (PTX). In this study, four PEG-Vitamin E conjugates were developed that vary in the molecular weight of PEG (PEG2K vs PEG5K) and the molar ratio of PEG/Vitamin E (1/1 vs 1/2) in the conjugates. These conjugates were systematically characterized with respect to CMC, PTX loading efficiency, stability, and their efficiency in delivery of PTX to tumor cells in vitro and in vivo. Our data show that PEG5K-conjugates have lower CMC values and are more effective in PTX loading with respect to both loading capacity and stability. The conjugates with two Vitamin E molecules also worked better than the conjugates with one molecule of Vitamin E, particularly for PEG2K-system. Furthermore, all of the PEG-Vitamin E conjugates can inhibit P-gp function with their activity being comparable to that of TPGS. More importantly, PTX-loaded PEG5K-VE2 resulted in significantly improved tumor growth inhibitory effect in comparison to PTX formulated in PEG2K-VE or PEG2K-VE2, as well as Cremophor EL (Taxol) in a syngeneic mouse model of breast cancer (4T1.2). Our study suggests that PEG5K-Vitmin E2 may hold promise as an improved micellar formulation for in vivo delivery of anticancer agents such as PTX. PMID:23768151

Lu, Jianqin; Huang, Yixian; Zhao, Wenchen; Chen, Yichao; Li, Jiang; Gao, Xiang; Venkataramanan, Raman; Li, Song

2013-01-01

192

Enabling Anticancer Therapeutics by Nanoparticle Carriers: The Delivery of Paclitaxel  

PubMed Central

Anticancer drugs, such as paclitaxel (PTX), are indispensable for the treatment of a variety of malignancies. However, the application of most drugs is greatly limited by the low water solubility, poor permeability, or high efflux from cells. Nanoparticles have been widely investigated to enable drug delivery due to their low toxicity, sustained drug release, molecular targeting, and additional therapeutic and imaging functions. This review takes paclitaxel as an example and compares different nanoparticle-based delivery systems for their effectiveness in cancer chemotherapy. PMID:21845085

Liu, Yongjin; Zhang, Bin; Yan, Bing

2011-01-01

193

Preclinical evaluation of nanoparticle albumin-bound paclitaxel for treatment of pediatric bone sarcoma.  

PubMed

The combination of docetaxel and gemcitabine is frequently used to treat recurrent bone sarcoma. Nanoparticle albumin-bound paclitaxel (nab-paclitaxel) is less toxic and more active than docetaxel or paclitaxel for breast cancer patients. The combination of nab-paclitaxel and gemcitabine has preclinical synergy and is approved to treat pancreatic cancer. We observed growth inhibition and improved survival with nab-paclitaxel in a Ewing sarcoma xenograft, and activity was additive with gemcitabine in an osteosarcoma model. Primary Ewing sarcoma tumors expressed the transport protein SPARC, previously associated with nab-paclitaxel activity. These findings provide rationale for further evaluation of nab-paclitaxel with gemcitabine for bone sarcoma. Pediatr Blood Cancer 2014;61:2096-2098. © 2014 Wiley Periodicals, Inc. PMID:24753077

Wagner, Lars M; Yin, Hong; Eaves, David; Currier, Mark; Cripe, Timothy P

2014-11-01

194

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

PubMed

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. PMID:7840821

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

1994-10-25

195

Chemo-enzymatic Synthesis of Propionyl-ester-linked Taxol-monosaccharide Conjugate and its Drug Delivery System Using Hybrid-Bio-nanocapsules Targeting Brain Glioma Cells  

PubMed Central

Taxol is recognized as one of the most potent anticancer agents used in the treatment of breast and ovarian cancers, which are common cancers in women. To overcome its shortcomings, that is, its low water-solubility that reduces drug loading capacity of DDS carriers when incorporating taxol, chemo-enzymatic synthesis of ester-linked taxol-glucose conjugate, i.e., 7-propionyltaxol 2?-O-?-D-glucoside, as a water soluble taxol prodrug was achieved by using a-glucosidase as a glucosylation catalyst. The water-solubility of 7-propionyltaxol 2?-O-?-D-glucoside (25 mM) was 63 fold higher than that of taxol (0.4 mM). The pre-S1 peptide which displays on the surface of bio-nanocapsules, which are nanoparticles composed of the hepatitis B virus surface antigen, was replaced with the antibody affinity motif of protein A. Conjugation of such bio-nanocapsules with anti-human epidermal growth factor receptor antibody gave hybrid bio-nanocapsules. The hybrid bio-nanocapsules were effective for delivering 7-propionyltaxol 2?-O-?-D-glucoside to human brain glioma cells. 7-Propionyltaxol 2?-O-?-D-glucoside was effectively hydrolyzed to give taxol in 95% by human glioma cells. The drug loading capacity of hybrid bio-nanocapsules incorporating 7-propionyltaxol 2?-O-?-D-glucoside was 120 times higher than that incorporating taxol itself. PMID:24665217

Hamada, Hiroki; Shimoda, Kei; Seno, Masaharu

2013-01-01

196

Differential sensitivity of human glioblastoma LN18 (PTEN-positive) and A172 (PTEN-negative) cells to Taxol for apoptosis  

PubMed Central

Glioblastoma is the most malignant brain tumors in humans and an average survival of glioblastoma patients hardly exceeds 12 months. Taxol is a plant-derived anti-cancer agent, which has been used in the treatments of many solid tumors. Deletion or mutation of phosphatase and tension homolog located on chromosome ten (PTEN) occurs in as high as 80% glioblastomas. We examined the sensitivity of human glioblastoma LN18 (PTEN-positive) and A172 (PTEN-negative) cells to Taxol for induction of apoptosis. Wright staining showed morphological features of apoptosis after treatment with different doses of Taxol for 24 h. Significant amount of apoptosis occurred in LN18 cells after treatment with 25 nM Taxol, while in A172 cells only after treatment with 50 nM Taxol. Western blotting with an antibody that could specifically detect activation or phosphorylation of Akt (p-Akt) did not show any p-Akt in LN18 cells but an increase in p-Akt in A172 cells. Activation of Akt in A172 cells could be reversed by pre-treatment of the cells with the phosphatidylinositol-3-kinase (PI3K) inhibitor LY294002, indicating involvement of PI3K activity in this process. Apoptosis occurred with an increase in Bax:Bcl-2 and mitochondrial release of cytochrome c into the cytosol leading to activation of mitochondria-dependent caspase cascade. Taxol did not cause upregulation of vascular endothelial growth factor (VEGF), a key mediator of angiogenesis, in LN18 cells but substantial upregulation of VEGF in A172 cells. After treatment with Taxol, increases in p-Akt and VEGF could maintain survival and angiogenesis, respectively, in PTEN-negative glioblastoma. As a single chemotherapy, Taxol might be more efficacious in PTEN-positive glioblastoma than in PTEN-negative glioblastoma. Thus, our study showed differential sensitivity of PTEN-positive and PTEN-negative glioblastoma cells to Taxol. PMID:18804099

Zhang, Ran; Banik, Naren L.; Ray, Swapan K.

2008-01-01

197

Epothilones, a New Class of Microtubule-stabilizing Agents with a Taxol-like Mechanism of Action  

Microsoft Academic Search

Tubulin polymerizationinto microtubulesis a dynamic process, with the equilibrium between growth and shrinkage being essential for many cellular processes. The antineoplastic agent taxol hyperstabilizes polymerized microtubules, leading to mitotic arrest and cytotoxicity in proliferating cells. Using a sensitive filtration-calorimetric assay to detect microtubule nucleating activity, we have identified epothilones A and B as compounds that possess all the biological effects

Daniel M. Bollag; Patricia A. McQueney; Jian Zhu; Otto Hensens; Lawrence Koupal; Jerrold Liesch; Michael Goetz; Elias Lazarides; Catherine M. Woods

1995-01-01

198

Synergistic dual-targeting hydrogel improves targeting and anticancer effect of Taxol in vitro and in vivo.  

PubMed

A synergistic dual-targeting molecular self-assembly hydrogel was designed with estrone (Et) and Arg-Gly-Asp (RGD) peptide. Confocal imaging in vitro and real-time visualization in vivo researches were carried out to evidence enhanced targeted delivery and anticancer effect of Taxol. PMID:25349928

Shu, Chang; Li, Ruixin; Yin, Yajun; Yin, Deyan; Gu, Yueqing; Ding, Li; Zhong, Wenying

2014-12-18

199

Improving the antitumor activity of squalenoyl-paclitaxel conjugate nanoassemblies by manipulating the linker between paclitaxel and squalene.  

PubMed

A series of new lipid prodrugs of paclitaxel, which can be formulated as nanoassemblies, are described. These prodrugs which are designed to overcome the limitations due to the systemic toxicity and low water solubility of paclitaxel consist of a squalene chain bound to the 2'-OH of paclitaxel through a 1,4-cis,cis-dienic linker. This design allows the squalene-conjugates to self-assemble as nanoparticular systems while preserving an efficient release of the free drug, thanks to the dienic spacer. The size, steric hindrance, and functional groups of the spacer have been modulated. All these prodrugs self-assemble into nanosized aggregates in aqueous solution as characterized by dynamic light scattering and transmission electron microscopy and appear stable in water for several days as determined by particle size measurement. In vitro biological assessment shows that these squalenoyl-paclitaxel nanoparticles display notable cytotoxicity on several tumor cell lines including A549 lung cell line, colon cell line HT-29, or KB 3.1 nasopharyngeal epidermoid cell line. The cis,cis-squalenyl-deca-5,8-dienoate prodrug show improved activity over simple 2'-squalenoyl-paclitaxel prodrug highlighting the favourable effect of the dienic linker. The antitumor efficacy of the nanoassemblies constructed with the more active prodrugs has been investigated on human lung (A549) carcinoma xenograft model in mice. The prodrug bearing the cis,cis-deca-5,8-dienoyl linker shows comparable antitumor efficacy to the parent drug, but reveals a much lower subacute toxicity as seen in body weight loss. Thus, nanoparticles with the incorporated squalenoyl paclitaxel prodrug may prove useful for replacement of the toxic Cremophor EL. PMID:23213041

Caron, Joachim; Maksimenko, Andrei; Wack, Séverine; Lepeltier, Elise; Bourgaux, Claudie; Morvan, Estelle; Leblanc, Karine; Couvreur, Patrick; Desmaële, Didier

2013-01-01

200

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.

201

BAD partly reverses paclitaxel resistance in human ovarian cancer cells  

Microsoft Academic Search

Although paclitaxel is an important chemotherapy agent for the treatment of patients with epithelial ovarian cancer, its utility is significantly limited by the frequent development of drug resistance. Recent evidence suggests that resistance to chemotherapy may be partly related to defects in the apoptotic pathway. In this study we have investigated whether enhancement of apoptotic pathway function through stable expression

Thomas Strobel; Yu-Tzu Tai; Stanley Korsmeyer; Stephen A Cannistra

1998-01-01

202

Kinetics of P-glycoprotein-mediated efflux of paclitaxel.  

PubMed

Paclitaxel is a substrate of the mdr1 P-glycoprotein (Pgp). The objective of the present study was to determine the kinetics of the Pgp-mediated efflux and its contribution to the overall efflux of paclitaxel at the clinically achievable concentration range of 1 to 1500 nM. Human breast carcinoma BC19 cells that were derived from MCF7 cells by mdr1 transfection and show a >10-fold higher level of the Pgp protein were used to measure the uptake and efflux of [(3)H]paclitaxel. A computational model of intracellular paclitaxel pharmacokinetics was developed to analyze for the Pgp efflux parameters. The results show a saturable Pgp-mediated efflux in BC19 cells; the dissociation constant was 14 nM, and the maximal efflux rate was 2.8 x 10(-4) pmol/h/cell. The contribution of Pgp-mediated efflux to the total efflux decreased with increasing extracellular drug concentrations; the Pgp efflux accounted for 86 and 34% of total efflux at 1 and 1500 nM, respectively. The validity of the model was confirmed by the close agreement between the model-predicted data and the experimentally obtained data (approximately 6% deviation) describing the effect of cell density and intracellular-to-extracellular concentration gradient on the kinetics of drug accumulation and efflux. In conclusion, our results indicate that the Pgp-mediated efflux represents a major efflux mechanism of paclitaxel at the low end of the clinically observed drug concentration range, but accounts for only a minor part of the efflux at higher concentrations in BC19 cells. PMID:11504826

Jang, S H; Wientjes, M G; Au, J L

2001-09-01

203

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. PMID:24220856

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

204

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

205

Purification and Characterization of Taxa4(5),11(12)-diene Synthase from Pacific Yew ( Taxus Brevifolia) that Catalyzes the First Committed Step of Taxol Biosynthesis  

Microsoft Academic Search

The first step in the biosynthesis of taxol in Pacific yew (Taxus brevifolia) is the cyclization of the universal diterpene precursor geranylgeranyl pyrophosphate to taxa-4(5),11(12)-diene. This parent olefin of the taxane diterpenoids is then elaborated to taxol and related compounds by a complex series of reactions involving oxidations and side-chain acylations. Cyclization activity is located principally in yew stem bark

M. Hezari; N. G. Lewis; R. Croteau

1995-01-01

206

Determination of taxol in Taxus species grown in Hungary by high-performance liquid chromatography-diode array detection effect of vegetative period  

Microsoft Academic Search

The influence of a vegetative period on the taxol content in the needles of Taxus brevifolia grown in Hungary was determined using porous graphitized carbon column and a HPLC-diode array detection system. The relative standard deviation of the retention time of taxol peak was 1.24%, the peak symmetry 1.06–1.07 indicating the reliability of the HPLC systems. It was found that

Veronika Németh-Kiss; Esther Forgács; Tibor Cserháti; Gábor Schmidt

1996-01-01

207

Amphiphilic dextran-graft-poly(epsilon-caprolactone) films for the controlled release of paclitaxel.  

PubMed

Amphiphilic graft copolymers with dextrans as the main chains and poly(epsilon-caprolactone) as the side chains were synthesized by solution polymerization in dimethyl sulfoxide using stannous 2-ethylhexanoate as a catalyst. The copolymers were characterized with nuclear magnetic resonance spectroscopy and gel permeation chromatography. Paclitaxel loaded copolymer films were prepared using a solution cast method. In vitro release rates were influenced by both the initial paclitaxel loading and the morphology of the films. The films with paclitaxel loadings up to 10% (w/w) showed a single-phase morphology when dry. However, paclitaxel crystallization occurred in the films with high loadings (5 and 10%) upon incubation in phosphate buffered saline at 37 degrees C. The crystals had a spherulitic structure and were found to be paclitaxel dihydrate based on X-ray diffraction analysis. The formation of paclitaxel dihydrate in the films produced a marked effect on the in vitro release rates. PMID:15129983

Shi, Ruiwen; Burt, Helen M

2004-03-01

208

Paclitaxel loaded nanosponges: in-vitro characterization and cytotoxicity study on MCF-7 cell line culture.  

PubMed

Beta cyclodextrin (?-CD) based nanosponges were synthesized and paclitaxel inclusion complex with nanosponges were prepared using techniques of inclusion complex formation. The paclitaxel nanosponge's complexes were evaluated for their release. The nanosponges complexes were also evaluated using DSC, FTIR, and NMR techniques for confirmation of inclusion complex formation between paclitaxel and nanosponges. Particle size and morphology of paclitaxel nanosponge's complex were estimated using SEM, TEM and dynamic light scattering techniques. The particle sizes were found out to be in range of 400 to 600 nm. Cytotoxic efficacy of paclitaxel nanosponge complex was determined against MCF-7 cells and paclitaxel nanosponge's complex was found to be cytotoxic and more effective against this cell line. PMID:21235471

Ansari, Khalid A; Torne, Satyen J; Vavia, Pradeep R; Trotta, Francesco; Cavalli, Roberta

2011-03-01

209

Expression of recombinant alpha and beta tubulins from the yew Taxus cuspidata and analysis of the microtubule assembly in the presence of taxol.  

PubMed

Taxol was originally isolated from the yew Taxus brevifolia. Because taxol inhibits the depolymerization of microtubules, the presence of a self-resistance mechanism in Taxus spp. was hypothesized. The cloning of the cDNA for alpha and beta tubulins from Taxus cuspidata and those from the human embryonic kidney cell line HEK293T revealed that the (26)Asp, (359)Arg, and (361)Leu residues in the human beta tubulin, which are important for taxol binding, were replaced with Glu, Trp, and Met in the beta tubulin of T. cuspidata, respectively. The microtubule assembly of the recombinant alpha and beta tubulins was monitored turbidimetrically, and the results clearly demonstrated that the microtubule from T. cuspidata is less sensitive to taxol than that from HEK293T cells. The Taxus microtubule composed of the wild-type alpha tubulin and the beta tubulin with the E26D mutation restored the sensitivity to taxol. We thus postulated that the mutation identified in the beta tubulin of T. cuspidata plays a role in the self-resistance of this species against taxol. PMID:25070196

Kudo, Yuma; Abe, Akihiro; Ito, Kumiko; Cho, Yuko; Yotsu-Yamashita, Mari; Konoki, Keiichi

2014-11-01

210

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. PMID:21796250

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

2011-01-01

211

Formulation and pharmacokinetic evaluation of a paclitaxel nanosuspension for intravenous delivery.  

PubMed

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 AUC(0-?) in liver, lung, and spleen (all P < 0.01), but not in heart or kidney. PMID:21796250

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

2011-01-01

212

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. PMID:23505544

Wang, Yingzhe; Teng, Quincy; Tan, Chalet

2013-01-01

213

Paclitaxel stimulates chromosomal fusion and instability in cells with dysfunctional telomeres: Implication in multinucleation and chemosensitization  

SciTech Connect

Research highlights: {yields} Paclitaxel serves as a stimulator of chromosomal fusion in cells in which telomeres are dysfunctional. {yields} Typical fusions involve p-arms, but paclitaxel-induced fusions occur between both q- and p-arms. {yields} Paclitaxel-stimulated fusions in cells in which telomeres are dysfunctional evoke prolonged G2/M cell cycle arrest and delay multinucleation. {yields} Upon telomere erosion, paclitaxel promotes chromosomal instability and subsequent apoptosis. {yields} Chromosomal fusion enhances paclitaxel chemosensitivity under telomere dysfunction. -- Abstract: The anticancer effect of paclitaxel is attributable principally to irreversible promotion of microtubule stabilization and is hampered upon development of chemoresistance by tumor cells. Telomere shortening, and eventual telomere erosion, evoke chromosomal instability, resulting in particular cellular responses. Using telomerase-deficient cells derived from mTREC-/-p53-/- mice, here we show that, upon telomere erosion, paclitaxel propagates chromosomal instability by stimulating chromosomal end-to-end fusions and delaying the development of multinucleation. The end-to-end fusions involve both the p- and q-arms in cells in which telomeres are dysfunctional. Paclitaxel-induced chromosomal fusions were accompanied by prolonged G2/M cell cycle arrest, delayed multinucleation, and apoptosis. Telomere dysfunctional cells with mutlinucleation eventually underwent apoptosis. Thus, as telomere erosion proceeds, paclitaxel stimulates chromosomal fusion and instability, and both apoptosis and chemosensitization eventually develop.

Park, Jeong-Eun [Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, Seoul 139-706 (Korea, Republic of)] [Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, Seoul 139-706 (Korea, Republic of); Woo, Seon Rang [Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, Seoul 139-706 (Korea, Republic of) [Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, Seoul 139-706 (Korea, Republic of); Department of Biochemistry, College of Medicine, Korea University, Seoul 136-705 (Korea, Republic of); Kang, Chang-Mo [Laboratory of Cytogenetics and Tissue Regeneration, Korea Institute of Radiological and Medical Sciences, Seoul 139-706 (Korea, Republic of)] [Laboratory of Cytogenetics and Tissue Regeneration, Korea Institute of Radiological and Medical Sciences, Seoul 139-706 (Korea, Republic of); Juhn, Kyoung-Mi; Ju, Yeun-Jin; Shin, Hyun-Jin; Joo, Hyun-Yoo; Park, Eun Ran; Park, In-chul; Hong, Sung Hee; Hwang, Sang-Gu [Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, Seoul 139-706 (Korea, Republic of)] [Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, Seoul 139-706 (Korea, Republic of); Lee, Jung-Kee [Department of Life Science and Genetic Engineering, Paichai University, Daejeon 302-735 (Korea, Republic of)] [Department of Life Science and Genetic Engineering, Paichai University, Daejeon 302-735 (Korea, Republic of); Kim, Hae Kwon [Department of Biotechnology, Seoul Woman's University, Seoul 139-774 (Korea, Republic of)] [Department of Biotechnology, Seoul Woman's University, Seoul 139-774 (Korea, Republic of); Cho, Myung-Haing [Laboratory of Toxicology, College of Veterinary Medicine, Seoul National University, Seoul 151-74-2 (Korea, Republic of)] [Laboratory of Toxicology, College of Veterinary Medicine, Seoul National University, Seoul 151-74-2 (Korea, Republic of); Park, Gil Hong [Department of Biochemistry, College of Medicine, Korea University, Seoul 136-705 (Korea, Republic of)] [Department of Biochemistry, College of Medicine, Korea University, Seoul 136-705 (Korea, Republic of); Lee, Kee-Ho, E-mail: khlee@kirams.re.kr [Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, Seoul 139-706 (Korea, Republic of)] [Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, Seoul 139-706 (Korea, Republic of)

2011-01-14

214

Supporting information for: Paclitaxel-Conjugated PAMAM Dendrimers Adversely  

E-print Network

OH:CH2Cl2) to yield the N-Boc protected cystamine-5 succinic acid (2) as a white solid (1.64 g, 21 %). Rf of paclitaxel (200 mg, 0.234 mmol) and the N-Boc protected cystamine-9 succinic acid (2; 87 mg, 0.246 mmol H (2) (Boc)2O, 12 h RT 1 2 34 PX, EDC/ DMF, 48 h RT TFA, CH2Cl2 20 min RT (1) Succinic anhydride Na

Walter, Nils G.

215

Comparative benefits of Nab-paclitaxel over gemcitabine or polysorbate-based docetaxel in experimental pancreatic cancer  

PubMed Central

Gemcitabine has limited clinical benefits in pancreatic ductal adenocarcinoma. The solvent-based traditional taxanes docetaxel and paclitaxel have not shown clinical results superior to gemcitabine. Nab-paclitaxel, a water-soluble albumin-bound paclitaxel, may carry superior distribution properties into the tumor microenvironment and has shown efficacy in multiple tumor types. We evaluated nab-paclitaxel effects compared with gemcitabine or docetaxel. For pancreatic ductal adenocarcinoma cells AsPC-1, BxPC-3, MIA PaCa-2 and Panc-1, gemcitabine IC50 ranged from 494nM to 23.9 ?M; docetaxel IC50 range was from 5 to 34nM; nab-paclitaxel IC50 range was from 243nM to 4.9 ?M. Addition of IC25 dose of docetaxel or nab-paclitaxel decreased gemcitabine IC50. Net tumor growth inhibition after gemcitabine, docetaxel or nab-paclitaxel was 67, 31 and 72%, which corresponded with intratumoral proliferative and apoptotic indices. Tumor stromal density was decreased by nab-paclitaxel and to a lesser extent by docetaxel as measured through reduction in ?-smooth muscle actin, S100A4 and collagen 1 expression. Animal survival was prolonged after nab-paclitaxel treatment (41 days, P < 0.002) compared with gemcitabine (32 days, P = 0.005), docetaxel (32 days, P = 0.005) and controls (20 days). Survival in nab-paclitaxel/gemcitabine and docetaxel/gemcitabine sequential treatment groups was not superior to nab-paclitaxel alone. Low-dose combination of gemcitabine with nab-paclitaxel or docetaxel was more effective compared with controls or gemcitabine alone but not superior to regular dose nab-paclitaxel alone. Combination treatment of gemcitabine+nab-paclitaxel or gemcitabine+docetaxel increased gemcitabine concentration in plasma and tumor. The superior antitumor activity of nab-paclitaxel provides a strong rationale for considering nab-paclitaxel as first-line monotherapy in pancreatic ductal adenocarcinoma. PMID:23803690

Schwarz, Roderich E.

2013-01-01

216

Extraction and RP-HPLC determination of taxol in rat plasma, cell culture and quality control samples  

PubMed Central

A rapid, sensitive, selective and validated reverse phase high-performance liquid chromatography (RP-HPLC) method for the estimation of paclitaxel in micro-sample of rat plasma and in culture of cancer cells was performed in this study. The mobile phase consisted of an optimized mixture of methanol:water: trifluroacetic acid (80: 20: 0.1, v/v/v). Column elution at a flow rate of 1 mL/minute with UV detection at 225 nm at room temperature was used. The RP-HPLC method was successfully applied for the determination of paclitaxel in plasma samples and in culture of cancer cells with nano-quantity of estimation. The validation studies were performed in accordance with the International Conference on Harmonization (ICH) guidelines. The intra- and inter-day precision showed that the coefficients of variation ranged from 1.07% to 4.27% at different levels of concentrations. To the best of our knowledge, this study also reported for the first time the optimization of different solvents for effective extraction of paclitaxel wherein tert.-butyl methyl ether (TBME): diethyl ether (DEE) in 50: 50 v/v composition was found most efficient with extraction efficiency ranging between 77.99% and 91.74% and between 76.14 and 93.66% in the plasma and cell culture, respectively. This proposed method was successfully applied to study the pharmacokinetics of paclitaxel and the influence of verapamil and all-trans retinoic acid (atRA) on paclitaxel pharmacokinetics in rat models. This proposed method might emerge as a valuable aid in the laboratory monitoring of paclitaxel in a variety of in vitro as well as in vivo scenarios. PMID:24086173

Tekade, Rakesh Kumar; D'Emanuele, Antony; Elhissi, Abdelbary; Agrawal, Ashish; Jain, Anurekha; Arafat, Basel Tawfiq; Jain, Narendra Kumar

2013-01-01

217

Chemical inhibitors suggest endophytic fungal paclitaxel is derived from both mevalonate and non-mevalonate-like pathways.  

PubMed

Taxus trees possess fungal endophytes reported to produce paclitaxel. Inhibitors that block early steps in plant paclitaxel biosynthesis were applied to a paclitaxel-producing fungus to determine whether these steps are shared. The plant paclitaxel backbone is reportedly derived from the non-mevalonate terpenoid pathway, while the side chain is phenylalanine-derived. Evidence that the shikimate pathway contributes to fungal paclitaxel was shown by decreased paclitaxel accumulation following inhibition of phenylalanine ammonia lyase. Expression of another shikimate pathway enzyme, 3-dehydroquinate synthase, coincided with paclitaxel production. The importance of the mevalonate pathway in fungal paclitaxel biosynthesis was shown by inhibition of fungal paclitaxel accumulation using compactin, a specific inhibitor of 3-hydroxy-3-methyl-glutaryl-CoA reductase. Expression of another mevalonate pathway enzyme, 3-hydroxy-3-methyl-glutaryl-CoA synthase, coincided with fungal paclitaxel accumulation. Unexpectedly, results from using fosmidomycin suggested that fungal paclitaxel requires 1-deoxy-D-xylulose-5-phosphate reductoisomerase (DXR), an enzyme in the 2-C-methyl-D-erythritol-4-phosphate (MEP) pathway normally found in bacteria/plants. Additional lines of evidence support this finding; first, a plant DXR antibody recognized a fungal peptide of the correct size; second, expression of an apparent fungal DXR ortholog correlated to changes in paclitaxel production; finally, BLAST searching identified a gene putatively encoding 1-deoxy-D-xylulose-5-phosphate synthase, the first enzyme in the MEP pathway in Aspergillus. PMID:22103292

Soliman, Sameh S M; Tsao, Rong; Raizada, Manish N

2011-12-27

218

Paclitaxel Induces Apoptosis in Breast Cancer Cells through Different Calcium—Regulating Mechanisms Depending on External Calcium Conditions  

PubMed Central

Previously, we reported that endoplasmic reticulum calcium stores were a direct target for paclitaxel initiation of apoptosis. Furthermore, the actions of paclitaxel attenuated Bcl-2 resistance to apoptosis through endoplasmic reticulum-mediated calcium release. To better understand the calcium-regulated mechanisms of paclitaxel-induced apoptosis in breast cancer cells, we investigated the role of extracellular calcium, specifically; whether influx of extracellular calcium contributed to and/or was necessary for paclitaxel-induced apoptosis. Our results demonstrated that paclitaxel induced extracellular calcium influx. This mobilization of extracellular calcium contributed to subsequent cytosolic calcium elevation differently, depending on dosage. Under normal extracellular calcium conditions, high dose paclitaxel induced apoptosis-promoting calcium influx, which did not occur in calcium-free conditions. In the absence of extracellular calcium an “Enhanced Calcium Efflux” mechanism in which high dose paclitaxel stimulated calcium efflux immediately, leading to dramatic cytosolic calcium decrease, was observed. In the absence of extracellular calcium, high dose paclitaxel’s stimulatory effects on capacitative calcium entry and apoptosis could not be completely restored. Thus, normal extracellular calcium concentrations are critical for high dose paclitaxel-induced apoptosis. In contrast, low dose paclitaxel mirrored controls, indicating that it occurs independent of extracellular calcium. Thus, extracellular calcium conditions only affect efficacy of high dose paclitaxel-induced apoptosis. PMID:24549172

Pan, Zhi; Avila, Andrew; Gollahon, Lauren

2014-01-01

219

EFFICIENT EXTRACTION OF PACLITAXEL AND RELATED TAXOIDS FROM LEAF TISSUE OF TAXUS USING A POTABLE SOLVENT SYSTEM  

Microsoft Academic Search

Leaves of Taxus x media and Taxus brevifolia were examined for their potential use as a source of paclitaxel and related taxoids. Various solvent systems were compared for their efficacy in the extraction of paclitaxel, as well as the extraction of contaminating residue. A method of extraction has been developed that enriches paclitaxel by over 500-fold using only potable solvents

Raymond E. B. Ketchum; Judy V. Luong; Donna M. Gibson

1999-01-01

220

Determinants of paclitaxel uptake, accumulation and retention in solid tumors.  

PubMed

This report addresses the determinants of the rate and extent of paclitaxel accumulation in tumors. In a 2-dimensional system such as monolayers where the drug is directly in contact with tumor cells, drug accumulation is determined by the extracellular-to-intracellular concentration gradient, the drug binding to extracellular and intracellular macromolecules, the presence of the mdrl p-glycoprotein (Pgp). and the time-dependent and drug concentration-dependent changes in tubulins and cell density. Intracellular pharmacokinetic models were developed to depict the effects of these parameters. Computer simulation results indicate that at the clinically relevant concentration range of 1 to 1,000 nM, (a) the binding affinity and the number of intracellular saturable drug binding sites are important for drug accumulation at low and high extracellular concentrations, respectively, (b) saturation in the drug binding to the high affinity intracellular binding sites (e.g., tubulin/microtubule) occurs at extracellular drug concentration above 100 nM, (c) treatment with 1,000 nM paclitaxel for >4 hr results in increased levels of tubulin/microtubule and consequently increased intracellular drug accumulation, whereas the continued cell proliferation after treatment with low drug concentrations results in reduced intracellular accumulation, and (d) saturation of Pgp in mdr1-transfected cells occurs at the high end of the clinically relevant concentration range. In a 3-dimensional system such as the solid tumor histocultures, which contain tumor cells as well as stromal cells, the drug accumulation into the inner cell layers is determined by the unique properties of solid tumors, including tumor cell density and spatial arrangement of tumor and stromal tissues. Most interestingly, drug penetration is modulated by the drug-induced apoptosis; the reduced cell density due to apoptosis results in an enhancement of the rate of drug penetration into the inner cell layers of solid tumors. In conclusion, the uptake, accumulation, and retention of paclitaxel in solid tumors are determined by (a) factors that are independent of biological changes in tumor cells induced by paclitaxel, i.e., ratio of extracellular and intracellular concentrations, and drug binding to extracellular and intracellular macromolecules, and (b) factors that are dependent on the time- and drug concentration-dependent biological changes induced by paclitaxel, i.e., induction of apoptosis, enhancement of tubulin/microtubule production, and induction of Pgp expression. PMID:11392446

Jang, S H; Wientjes, M G; Au, J L

2001-05-01

221

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

222

Paclitaxel: A Pharmacoeconomic Review of its Use in the Treatment of Ovarian Cancer  

Microsoft Academic Search

Paclitaxel belongs to the group of antitumour agents called the taxanes. Its efficacy in advanced ovarian cancer has been established in large, randomised phase III clinical trials. When used in combination with cisplatin for first-line treatment of advanced ovarian cancer, it is superior to cyclophosphamide\\/cisplatin, with gains in median survival of around 1 year. Paclitaxel plus carboplatin has similar efficacy

Melissa Young; Greg L. Plosker

2001-01-01

223

Combination of Nab-Paclitaxel and Gemcitabine Improves Survival in Patients with Metastatic Pancreatic Cancer  

Cancer.gov

In an international randomized phase III trial, patients with metastatic pancreatic cancer who were treated with a combination of albumin-bound paclitaxel (nab-paclitaxel [Abraxane®]) and gemcitabine (Gemzar®) lived longer than patients who were treated with gemcitabine alone. Patients who received both drugs also lived longer without their disease getting worse (progression-free survival).

224

Beyond taxol: microtubule-based treatment of disease and injury of the nervous system  

PubMed Central

Contemporary research has revealed a great deal of information on the behaviours of microtubules that underlie critical events in the lives of neurons. Microtubules in the neuron undergo dynamic assembly and disassembly, bundling and splaying, severing, and rapid transport as well as integration with other cytoskeletal elements such as actin filaments. These various behaviours are regulated by signalling pathways that affect microtubule-related proteins such as molecular motor proteins and microtubule severing enzymes, as well as a variety of proteins that promote the assembly, stabilization and bundling of microtubules. In recent years, translational neuroscientists have earmarked microtubules as a promising target for therapy of injury and disease of the nervous system. Proof-of-principle has come mainly from studies using taxol and related drugs to pharmacologically stabilize microtubules in animal models of nerve injury and disease. However, concerns persist that the negative consequences of abnormal microtubule stabilization may outweigh the positive effects. Other potential approaches include microtubule-active drugs with somewhat different properties, but also expanding the therapeutic toolkit to include intervention at the level of microtubule regulatory proteins. PMID:23811322

Ahmad, Fridoon J.

2013-01-01

225

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. PMID:18068629

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

226

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

227

Thermoreversible Pluronic® F127-based hydrogel containing liposomes for the controlled delivery of paclitaxel: in vitro drug release, cell cytotoxicity, and uptake studies  

PubMed Central

Purpose To develop an in situ gel system comprising liposome-containing paclitaxel (PTX) dispersed within the thermoreversible gel (Pluronic® F127 gel) for controlled release and improved antitumor drug efficiency. Methods The dialysis membrane and membrane-less diffusion method were used to investigate the in vitro drug release behavior. Differential scanning calorimetry (DSC) thermal analysis was used to investigate the “micellization” and “sol/gel transition” process of in situ gel systems. In vitro cytotoxicity and drug uptake in KB cancer cells were determined by MTT, intercellular drug concentration, and fluorescence intensity assay. Results The in vitro release experiment performed with a dialysis membrane model showed that the liposomal gel exhibited the longest drug-release period compared with liposome, general gel, and commercial formulation Taxol®. This effect is presumably due to the increased viscosity of liposomal gel, which has the effect of creating a drug reservoir. Both drug and gel release from the in situ gel system operated under zero-order kinetics and showed a correlation of release of PTX with gel, indicating a predominating release mechanism of the erosion type. Dispersing liposomes into the gel replaced larger gel itself for achieving the same gel dissolution rate. Both the critical micelle temperature and the sol/gel temperature, detected by DSC thermal analysis, were shifted to lower temperatures by adding liposomes. The extent of the shifts depended on the amount of embedded liposomes. MTT assay and drug uptake studies showed that the treatment with PTX-loaded liposomal 18% Pluronic F127 yielded cytotoxicities, intercellular fluorescence intensity, and drug concentration in KB cells much higher than that of conventional liposome, while blank liposomal 18% Pluronic F127 gel was far less than the Cremophor EL® vehicle and empty liposomes. Conclusions A thermosensitive hydrogel with embedded liposome is a promising carrier for hydrophobic anticancer agents, to be used in parenteral formulations for treating local cancers. PMID:21499415

Nie, Shufang; Hsiao, WL Wendy; Pan, Weisan; Yang, Zhijun

2011-01-01

228

Fmoc-Conjugated PEG-Vitamin E2 Micelles for Tumor-Targeted Delivery of Paclitaxel: Enhanced Drug-Carrier Interaction and Loading Capacity.  

PubMed

The purpose of this study is to develop an improved drug delivery system for enhanced paclitaxel (PTX) loading capacity and formulation stability based on PEG5K-(vitamin E)2 (PEG5K-VE2) system. PEG5K-(fluorenylmethoxycarbonyl)-(vitamin E)2 (PEG5K-FVE2) was synthesized using lysine as the scaffold. PTX-loaded PEG5K-FVE2 micelles were prepared and characterized. Fluorescence intensity of Fmoc in the micelles was measured as an indicator of drug-carrier interaction. Cytotoxicity of the micelle formulations was tested on various tumor cell lines. The therapeutic efficacy and toxicity of PTX-loaded micelles were investigated using a syngeneic mouse model of breast cancer (4T1.2). Our data suggest that the PEG5K-FVE2 micelles have a low CMC value of 4 ?g/mL and small sizes (~60 nm). The PTX loading capacity of PEG5K-FVE2 micelles was much higher than that of PEG5K-VE2 micelles. The Fmoc/PTX physical interaction was clearly demonstrated by a fluorescence quenching assay. PTX-loaded PEG5K-FVE2 micelles exerted more potent cytotoxicity than free PTX or Taxol formulation in vitro. Finally, intravenous injection of PTX-loaded PEG5K-FVE2 micelles showed superior anticancer activity compared with PEG5K-VE2 formulation with minimal toxicity in a mouse model of breast cancer. In summary, incorporation of a drug-interactive motif (Fmoc) into PEG5K-VE2 micelles represents an effective strategy to improve the micelle formulation for the delivery of PTX. PMID:25193267

Zhang, Yifei; Huang, Yixian; Zhao, Wenchen; Lu, Jianqin; Zhang, Peng; Zhang, Xiaolan; Li, Jiang; Gao, Xiang; Venkataramanan, Raman; Li, Song

2014-11-01

229

Hydrotropic Polymeric Micelles for Enhanced Paclitaxel Solubility: In Vitro and In Vivo Characterization  

PubMed Central

The purpose of this investigation was to characterize the in vitro stability and in vivo disposition of paclitaxel in rats after solubilization of paclitaxel into hydrotropic polymeric micelles. The amphiphilic block copolymers consisted of micellar a shell-forming poly(ethylene glycol) (PEG) block and a core-forming poly(2-(4-vinylbenzyloxy)-N,N-diethylnicotinamide) (P(VBODENA)) block. N,N-Diethylnicotinamide (DENA) in the micellar inner core resulted in effective paclitaxel solubilization and stabilization. Solubilization of paclitaxel using polymeric micelles of poly(ethylene glycol)-b-P(D,L-lactide) (PEG-b-PLA) served as a control for the stability study. Up to 37.4 wt% paclitaxel could be loaded in PEG-b-P(VBODENA) micelles, whereas the maximum loading amount for PEG-b-PLA micelles was 27.6 wt%. Thermal analysis showed that paclitaxel in the polymeric micelles existed in the molecularly dispersed amorphous state even at loadings over 30 wt%. Paclitaxel-loaded hydrotropic polymeric micelles retained their stability in water for weeks, whereas paclitaxel-loaded PEG-b-PLA micelles precipitated in a few days. Hydrotropic polymer micelles were more effective than PEG-PLA micelle formulations in inhibiting the proliferation of human cancer cells. Paclitaxel in hydrotropic polymer micelles was administered orally (3.8 mg/kg), intravenously (2.5 mg/kg) or via the portal vein (2.5 mg/kg) to rats. The oral bioavailability was 12.4% of the intravenous administration. Our data suggest that polymeric micelles with a hydrotropic structure are superior as a carrier of paclitaxel due to a high solubilizing capacity combined with long-term stability which has not been accomplished by other existing polymeric micelle systems. PMID:17206808

Lee, Sang Cheon; Huh, Kang Moo; Lee, Jaehwi; Cho, Yong Woo; Galinsky, Raymond E.; Park, Kinam

2008-01-01

230

KSP inhibitor ARRY-520 as a substitute for Paclitaxel in Type I ovarian cancer cells  

PubMed Central

Background We previously described a sub-population of epithelial ovarian cancer (EOC) cells with a functional TLR-4/MyD88/NF-?B pathway (Type I EOC cells), which confers the capacity to respond to Paclitaxel, a known TLR-4 ligand, by enhancing NF-?B activity and upregulating cytokine secretion – events that are known to promote tumor progression. It is therefore important to distinguish those patients that should not receive Paclitaxel; it is also important to identify alternative chemotherapy options that would benefit this sub-group of patients. The objective of this study is to determine if the KSP inhibitor, ARRY-520, can be a substitute for Paclitaxel in patients with Type I EOC. Methods EOC cells isolated from either ascites or tumor tissue were treated with increasing concentrations of ARRY-520 or Paclitaxel and cell viability determined. Activation of the apoptotic pathway was determined using Western blot analysis. Mitochondrial integrity was quantified using JC1 dye. Cytokine profiling was performed from supernatants using xMAP technology. NF-?B activity was measured using a Luciferase reporter system. In vivo activity was determined using a subcutaneous xenograft mouse model. Results ARRY-520 and Paclitaxel exhibited the same cytotoxic effect on Type I and II cells. The GI50 at 48 h for Type II EOC cells was 0.0015 ?M and 0.2 ?M for ARRY-520 and Paclitaxel, respectively. For Type I EOC cells, the GI50 at 48 h was > 3 ?M and >20 ?M for ARRY-520 and Paclitaxel, respectively. Decrease in the number of viable cells was accompanied by mitochondrial depolarization and caspase activation. Unlike Paclitaxel, ARRY-520 did not induce NF-?B activation, did not enhance cytokine secretion, nor induce ERK phosphorylation in Type I EOC cells. Conclusion Administration of Paclitaxel to patients with high percentage Type I cancer cells could have detrimental effects due to Paclitaxel-induced enhancement of NF-?B and ERK activities, and cytokine production (e.g. IL-6), which promote chemoresistance and tumor progression. ARRY-520 has similar anti-tumor activity in EOC cells as that of Paclitaxel. However, unlike Paclitaxel, it does not induce these pro-tumor effects in Type I cells. Therefore, the KSP inhibitor ARRY-520 may represent an alternative to Paclitaxel in this subgroup of EOC patients. PMID:19619321

Kim, Ki Hyung; Xie, Yanhua; Tytler, Ewan M; Woessner, Richard; Mor, Gil; Alvero, Ayesha B

2009-01-01

231

Effects of Goshajinkigan, Hachimijiogan, and Rokumigan on Mechanical Allodynia Induced by Paclitaxel in Mice  

PubMed Central

Peripheral neuropathy is a major dose-limiting side effect of the chemotherapeutic agent paclitaxel. This study examined whether the three related traditional herbal formulations, goshajinkigan (GJG; ????? Niú Ch? Shèn Qì Wán), hachimijiogan (HJG; ????? B? Wèi Dì Huáng Wán), and rokumigan (RMG; ??? Liù Wèi Wán), would relieve paclitaxel-induced mechanical allodynia in mice. A single intraperitoneal injection of paclitaxel (5 mg/kg) induced mechanical allodynia, which peaked on day 14 after injection. On day 14 after paclitaxel injection, oral administration of GJG (0.1-1.0 g/kg) produced a significant inhibition of established allodynia, but HJG and RMG did not affect the allodynia. Repeated oral administration of GJG (0.1-1.0 g/kg) starting from the day after paclitaxel injection did not affect allodynia development, but significantly inhibited allodynia exacerbation. Repeated oral administration of HJG produced a slight inhibition of allodynia exacerbation, but that of RMG did not. These results suggest that prophylactic administration of GJG is effective in preventing the exacerbation of paclitaxel-induced allodynia. The herbal medicines Plantaginis Semen (??? Ch? Qián Z?) and Achyranthis Radix (?? Niú X?), which are present in GJG but not in HJG, may contribute to the inhibitory action of GJG on the exacerbation of paclitaxel-induced allodynia. PMID:25379475

Andoh, Tsugunobu; Kitamura, Ryo; Fushimi, Hirotoshi; Komatsu, Katsuko; Shibahara, Naotoshi; Kuraishi, Yasushi

2014-01-01

232

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

233

Efficient purification of paclitaxel from yews using high-performance displacement chromatography technique.  

PubMed

Paclitaxel was purified using high-performance displacement chromatography (HPDC) technique, but not by the mechanism of HPDC. On small scale, paclitaxel was extracted with methanol from dry needles of Taxus canadensis and was enriched by extracting with chloroform after removing water-soluble hydrophilic components and hexane-soluble hydrophobic components. Then, 93-99% purity of paclitaxel was obtained using the HPDC technique. On large scale, taxanes were enriched by solvent partitioning between acetic acid/MeOH/H(2)O and hexane and extracted with CH(2)Cl(2). Taxanes except paclitaxel were further removed by extracting with methanol-water-trifluoroacetic acid (1.0:98.9:0.1, v/v/v). Applying HPDC technique to water-insoluble substances is problematic as this method requires a highly aqueous solvent system. In order to overcome this incompatibility, a system was set up where paclitaxel, although in low concentration, was extracted by methanol-water-trifluoroacetic acid (10.0:89.9:0.1, v/v/v). Recycling the extracting solvent to ensure minimal volume, the extracted paclitaxel was adsorbed on a C(18) trap column. A C(18) column of 4.6mm internal diameter was then connected to the trap column. The HPDC technique was thus carried out using an isocratic acetonitrile-water-trifluoroacetic acid (30.0:69.9:0.1, v/v/v) mobile phase consisting of a displacer cetylpyridinium trifluoroacetate (3mg/mL). Paclitaxel was co-eluted with the displacer and spontaneously crystallized. The crystal (114mg) showed 99.4% purity and only 10% of paclitaxel in the starting crude extract was lost during the enrichment/purification processes. This large scale purification method was successfully applied to purify paclitaxel from Chinese yew in small scale, suggesting general applicability of the method. This is the first report of purifying a water-insoluble natural product using HPDC technique. PMID:21457989

Watchueng, Jean; Kamnaing, Pierre; Gao, Jin-Ming; Kiyota, Taira; Yeboah, Faustinus; Konishi, Yasuo

2011-05-20

234

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

235

Hydrotropic polymer micelle system for delivery of paclitaxel.  

PubMed

Hydrotropic polymer micelle system has been developed for delivery of poorly water-soluble drugs such as paclitaxel. Hydrotropic polymers based on N,N-diethylnicotinamide were synthesized and used as a hydrophobic block for constructing amphiphilic block copolymers. The hydrotropic block copolymers self-assembled to form micelles in aqueous media. The size of the prepared polymer micelles was in the range of 30-50 nm, and increased to 100-120 nm after paclitaxel loading. The critical micelle concentrations (CMCs) of the block copolymers were higher by an order of magnitude than those of other typical polymer micelles, due to less hydrophobicity of the hydrotropic blocks. The drug loading capacity and physical stability of the polymer micelles were characterized and compared with those of other polymer micelles. The hydrotropic polymer micelles containing hydrotrope-rich cores showed not only higher loading capacity but also enhanced physical stability in aqueous media. They could be redissolved in aqueous media by simple vortexing and/or a mild heating. The hydrotropic polymer micelles provide an alternative approach for formulation of poorly soluble drugs. PMID:15588894

Huh, Kang Moo; Lee, Sang Cheon; Cho, Yong Woo; Lee, Jaehwi; Jeong, Jae Hyun; Park, Kinam

2005-01-01

236

Cytotoxicity of Paclitaxel Incorporated in PLGA Nanoparticles on Hypoxic Human Tumor Cells  

Microsoft Academic Search

Purpose  The aim of this work was to prepare paclitaxel-loaded PLGA nanoparticles and determine cytotoxicity of released paclitaxel\\u000a for two hypoxic human tumor cell lines: breast carcinoma (MCF-7) and carcinoma cervicis (HeLa).\\u000a \\u000a \\u000a \\u000a Methods  Poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles containing paclitaxel were prepared by o\\/w emulsification-solvent evaporation\\u000a method. Physicochemical characteristics of nanoparticles were studied. Cellular uptake of nanoparticles was evaluated by transmission\\u000a electronic microscopy and

Cheng Jin; Ling Bai; Hong Wu; Wenjie Song; Guozhen Guo; Kefeng Dou

2009-01-01

237

Rhein lysinate suppresses the growth of tumor cells and increases the anti-tumor activity of Taxol in mice.  

PubMed

In previous studies, rhein, one of the major bioactive constituents in the rhizome of rhubarb, inhibited the proliferation of various human cancer cells. However, because of its water insolubility, the anti-tumor efficacy of rhein was limited in vivo. In this study, we observed the anti-tumor activity of rhein lysinate (the salt of rhein and lysine easily dissolves in water) in vivo and investigated its mechanism. Inhibition of ovarian cancer SKOV-3 cell proliferation was determined by MTT assay and the mechanism of action of rhein lysinate was investigated by Western blot analysis. The therapeutic efficacy of rhein lysinate was evaluated by intragastric and intraperitoneal administrations in H22 hepatocellular carcinoma mice. Rhein lysinate inhibited the proliferation of SKOV-3 cells and the IC50 value was 80 microM. Rhein lysinate inhibited the phosphorylation of MEK and ERK and increased the anti-tumor activity of Taxol in vitro. It inhibited tumor growth by both intragastric and intraperitoneal administrations and improved the therapeutic effect of Taxol in H22 hepatocellular carcinoma mice. In conclusion, rhein lysinate offers an anti-tumor activity in vivo and is hopeful to be a chemotherapeutic drug. PMID:19885952

Lin, Ya-Jun; Zhen, Yong-Zhan; Shang, Bo-Yang; Zhen, Yong-Su

2009-01-01

238

Purification, cloning, and functional expression of phenylalanine aminomutase: the first committed step in Taxol side-chain biosynthesis.  

PubMed

The conversion of alpha-phenylalanine to beta-phenylalanine is the first committed step in the biosynthesis of the C-13 side chain of Taxol. Thus, the novel enzyme responsible for this step, phenylalanine aminomutase (PAM), is of considerable interest for studies of Taxol biosynthesis and represents a potential target for genetic engineering. A method is described for purifying PAM from Taxus chinensis cell cultures. The purified enzyme has a K(m) of 1.1mM, a V(max) of 110.1 microm/min/mg protein, a pH optimum of 7.5-8.0, and a denatured molecular weight of about 80 kDa. Peptide sequences derived from the purified protein were used to design and synthesize degenerate primers enabling the PCR synthesis of the PAM cDNA. The PAM cDNA encodes a protein of 687 amino acid residues with a deduced molecular weight of 75.3 kDa. The PAM cDNA was cloned and expressed in Escherichia coli, and PAM activity was demonstrated. As a gene symbol for the PAM enzyme, pam is proposed. Protein sequence alignments of PAM, phenylalanine ammonia-lyase (PAL), and histidine ammonia-lyase (HAL) sequences exhibit significant similarity providing insight into potential active site residues of PAM. PMID:15878763

Steele, Christopher L; Chen, Yijun; Dougherty, Brian A; Li, Wenying; Hofstead, Sandra; Lam, Kin S; Xing, Zizhuo; Chiang, Shu-Jen

2005-06-01

239

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

240

Short Communication Coating with paclitaxel improves graft survival in a porcine model of  

E-print Network

patency at 5, 6, 6 and 8 weeks, respectively. In Kaplan­Meier analysis, paclitaxel- coated grafts showed and subsequent thrombosis. Several pharmacologic agents, such as warfarin, aspirin and clopidogrel, have been

Park, Jong-Sang

241

N-Labled Synthons for Taxol and Its Analogs Bull. Korean Chem. Soc. 2001, Vol. 22, No. 5 493 An Efficient and Eco-friendly Approach to 15  

E-print Network

An Efficient and Eco-friendly Approach to 15 N-Unsubstituted -Lactams: 15 N-Labled Synthons for Taxol and Its Received January 30, 2001 An efficient and eco-friendly approach to N-unsubstituted -lactams has been on environmentally benign organic synthesis, we have sought eco-friendly reactions that could lead to various -lactam

242

Cost-effectiveness of paclitaxel plus cisplatin in advanced non-small-cell lung cancer  

PubMed Central

The aim of this study was to assess the cost-effectiveness of combination chemotherapy with paclitaxel/cisplatin, compared with standard etoposide/cisplatin in patients with advanced non-small cell lung cancer (NSCLC). We obtained the primary survival and resource utilization data from a large three-arm randomized trial comparing: paclitaxel 135 mg m?2 by 24-h intravenous (i.v.) infusion + cisplatin; paclitaxel 250 mg m?2 by 24-h i.v. infusion + cisplatin + granulocyte colony-stimulating factor (G-CSF); and standard etoposide/cisplatin in patients with stage IIIb or IV NSCLC. We also modelled the regimens with paclitaxel 135 mg m?2 + cisplatin administered as an outpatient by 3-h infusion, as clinical data suggest that this is equivalent to 24-h infusion. We collected costing data from the Ottawa Regional Cancer Centre and applied it to the resources consumed in the randomized trial. We integrated these data into the Statistics Canada POpulation HEalth Model (POHEM), which generated hypothetical cohorts of patients treated with each regimen. The POHEM model assigned diagnostic work-up, treatment, disease progression and survival characteristics to each individual in these cohorts and tabulated the costs associated with each. We did sensitivity analyses around the costs of chemotherapy and its administration, and the survival differences between the two regimens. All costs are in 1997 Canadian dollars ($1.00 Canadian ˜ £0.39 sterling). The perspective is that of the Canadian health care system. In the trial, the two paclitaxel-containing arms had almost identical survival curves with a median survival of 9.7 months compared with 7.4 months for etoposide/cisplatin. As administered in the trial, paclitaxel/cisplatin cost $76 370 per life-year gained (LYG) and paclitaxel/cisplatin/G-CSF $138 578 per LYG relative to etoposide/cisplatin. However, when modelled as an outpatient 3-h infusion, paclitaxel/cisplatin was moderately cost-effective at $30 619 per LYG. When compared with historical controls treated with best supportive care, this regimen of paclitaxel/cisplatin cost $4539 per LYG. Assuming a 3-h paclitaxel infusion yields the same survival advantage as the 24-h infusion did in the randomized trial, paclitaxel/cisplatin is a cost-effective improvement over standard etoposide/cisplatin for patients with advanced non-small cell lung cancer. © 1999 Cancer Research Campaign PMID:10360660

Earle, C C; Evans, W K

1999-01-01

243

Targeting carrier-mediated transport to improve the blood-brain barrier permeation of paclitaxel  

E-print Network

TARGETING CARRIER-MEDIATED TRANSPORT TO IMPROVE THE BLOOD-BRAIN BARRIER PERMEATION OF PACLITAXEL Kelly E. Desino1, Kenneth L. Audus1, Haibo Ge2, Gunda I. Georg2, Jariat Oyetunji2, Jared T. Spletstoser2, and Brandon J. Turunen2 University of Kansas..., Department of Pharmaceutical Chemistry1 and Department of Medicinal Chemistry2, Lawrence, KS 66047 ABSTRACT Purpose: Paclitaxel is a chemotherapeutic used for a variety of cancers; however, it cannot be used for cancers of the CNS. The permeation...

Desino, Kelly Elizabeth; Audus, Kenneth L.; Ge, Haibo; Georg, Gunda I.; Oyetunji, Jariat; Spletstoser, J. T.; Turunen, B. J.

2006-10-27

244

Paclitaxel Stent Coating Inhibits Neointimal Hyperplasia at 4 Weeks in a Porcine Model of Coronary Restenosis  

Microsoft Academic Search

Background—Despite limiting elastic recoil and late vascular remodeling after angioplasty, coronary stents remain vulnerable to restenosis, caused primarily by neointimal hyperplasia. Paclitaxel, a microtubule-stabilizing drug, has been shown to inhibit vascular smooth muscle cell migration and proliferation contributing to neointimal hyperplasia. We tested whether paclitaxel-coated coronary stents are effective at preventing neointimal proliferation in a porcine model of restenosis. Methods

Alan W. Heldman; Linda Cheng; G. Mark Jenkins; Phillip F. Heller; Dong-Woon Kim; Melvin Ware; Cynthia Nater; Ralph H. Hruban; Banafsheh Rezai; Benjamin S. Abella; Katherine E. Bunge; James L. Kinsella; Steven J. Sollott; Edward G. Lakatta; Jeffrey A. Brinker; William L. Hunter; Jeffrey P. Froehlich

2010-01-01

245

Molecular predictors of efficacy of adjuvant weekly paclitaxel in early breast cancer  

Microsoft Academic Search

Treatment with fluororacil, epirubicin, and cyclophosphamide followed by weekly paclitaxel (FEC-P) yielded superior disease-free\\u000a survival than FEC in the adjuvant breast cancer trial GEICAM 9906. We evaluate molecular subtypes predictive of prognosis\\u000a and paclitaxel response in this trial. Two molecular subtype classifications based on conventional immunohistochemical and\\u000a fluorescent in situ hybridization determinations were used: #1: Four groups segregated according to

Miguel Martín; Álvaro Rodríguez-Lescure; Amparo Ruiz; Emilio Alba; Lourdes Calvo; Manuel Ruiz-Borrego; Ana Santaballa; César A. Rodríguez; Carmen Crespo; Mar Abad; Severina Domínguez; Jesús Florián; Cristina Llorca; Miguel Méndez; María Godes; Ricardo Cubedo; Adolfo Murias; Norberto Batista; María José García; Rosalía Caballero; Enrique de Álava

2010-01-01

246

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

247

Paclitaxel-loaded PLGA nanoparticles: preparation, physicochemical characterization and in vitro anti-tumoral activity  

Microsoft Academic Search

The main objective of this study was to develop a polymeric drug delivery system for paclitaxel, intended to be intravenously administered, capable of improving the therapeutic index of the drug and devoid of the adverse effects of Cremophor® EL. To achieve this goal paclitaxel (Ptx)-loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticles (Ptx-PLGA-Nps) were prepared by the interfacial deposition method. The influence of

Cristina Fonseca; Sérgio Simões; Rogério Gaspar

2002-01-01

248

[Adenovirus-mediated interleukin-24 enhances the inhibitory effect of paclitaxel on the growth of lung cancer A549 cells].  

PubMed

Objective To investigate the effect of adenovirus-mediated interleukin-24 (Ad-IL-24) combined with paclitaxel on the growth of human lung cancer A549 cells in vitro. Methods A549 cells were treated with Ad-IL-24 alone, paclitaxel alone and Ad-IL-24 combined with paclitaxel, respectively. Their proliferation was detected by CCK-8 assay, and the changes of apoptosis and cell cycle were tested by flow cytometry. Results The treatment of Ad-IL-24 significantly inhibited the A549 cell growth and induced cell apoptosis. Compared with paclitaxel alone and Ad-IL-24 alone, the Ad-IL-24 plus paclitaxel treatment more evidently inhibited lung cancer cell growth and increased cell apoptosis rate, and induced G2/M phase arrest. Conclusion Ad-IL-24 infection can enhance the inhibitory effect of paclitaxel on lung cancer cell growth. PMID:25374078

Xu, Mingju; Li, Minmin; Yang, Jicheng; Guo, Jinjin; Sun, Wanbang

2014-11-01

249

Polygenic inheritance of paclitaxel-induced sensory peripheral neuropathy driven by axon outgrowth gene sets in CALGB 40101 (Alliance).  

PubMed

Peripheral neuropathy is a common dose-limiting toxicity for patients treated with paclitaxel. For most individuals, there are no known risk factors that predispose patients to the adverse event, and pathogenesis for paclitaxel-induced peripheral neuropathy is unknown. Determining whether there is a heritable component to paclitaxel-induced peripheral neuropathy would be valuable in guiding clinical decisions and may provide insight into treatment of and mechanisms for the toxicity. Using genotype and patient information from the paclitaxel arm of CALGB 40101 (Alliance), a phase III clinical trial evaluating adjuvant therapies for breast cancer in women, we estimated the variance in maximum grade and dose at first instance of sensory peripheral neuropathy. Our results suggest that paclitaxel-induced neuropathy has a heritable component, driven in part by genes involved in axon outgrowth. Disruption of axon outgrowth may be one of the mechanisms by which paclitaxel treatment results in sensory peripheral neuropathy in susceptible patients. PMID:24513692

Chhibber, A; Mefford, J; Stahl, E A; Pendergrass, S A; Baldwin, R M; Owzar, K; Li, M; Winer, E P; Hudis, C A; Zembutsu, H; Kubo, M; Nakamura, Y; McLeod, H L; Ratain, M J; Shulman, L N; Ritchie, M D; Plenge, R M; Witte, J S; Kroetz, D L

2014-08-01

250

Cost-Benefit Analysis of Nanoparticle Albumin-Bound Paclitaxel versus Solvent-Based Paclitaxel for the Treatment of Metastatic Breast Cancer in the United States  

NASA Astrophysics Data System (ADS)

Breast cancer is the second leading cause of death among women in the US. Although early detection and treatment help to increase survival rates, some unfortunate patients develop metastatic breast cancer that has no cure. Palliative treatment is the main objective in this group of patients in order to prolong life and reduce toxicities from interventions. In the advancement of treatment for metastatic breast cancer, solvent-based paclitaxel has been widely used. However, solvent-based paclitaxel often causes adverse reactions. Therefore, researchers have developed a new chemotherapy based on nanotechnology. One of these drugs is the Nanoparticle albumin-bound Paclitaxel. This nanodrug aims to increase therapeutic index by reducing adverse reactions from solvents and to improve efficacy of conventional cytotoxic chemotherapy. Breast cancer is a disease with high epidemiological and economic burden. The treatment of metastatic breast cancer has not only high direct costs but also high indirect costs. Breast cancer affects mass populations, especially women younger than 50 years of age. It relates to high indirect costs due to lost productivity and premature death because the majority of these patients are in the workforce. Because of the high cost of breast cancer therapies and short survival rates, the question is raised whether the costs and benefits are worth paying or not. Due to the rising costs in healthcare and new financing policies that have been developed to address this issue, economic evaluation is an important aspect of the development and use of any new interventions. To guide policy makers on how to allocate limited healthcare resources in the most efficient and effective manner, many economic evaluation methods can be used to measure the costs, benefits, and impacts of healthcare innovations. Currently, economic evaluation and health outcomes studies have focused greatly on cost-effectiveness and cost-utility analysis. However, the previous studies had some limitations because they were conducted from a narrow perspective such as payer and provider point of views. The studies also considered only direct costs in their analysis. In fact, conducting economic evaluations from a narrow perspective and leaving out indirect costs might undermine the true benefit of the interventions for society. A cost-benefit analysis measures all costs and benefits in monetary units. It incorporates both health outcomes gained from individuals and the value gained to society in order to maximize the usage of resources effectively. This thesis conducted a cost-benefit analysis to compare nab-paclitaxel and generic paclitaxel in treating metastatic breast cancer from a societal perspective in the United States. The results showed that nab-paclitaxel is a cost-benefit strategy regardless of the different costs and benefits due to the extra 3 years of living it provides. In all models, when nab-paclitaxel was compared to generic paclitaxel, nab-paclitaxel showed cost-benefit to society. However, the results of generic paclitaxel were dependent on the total medical costs. Performing a cost-benefit analysis of nab-paclitaxel from a societal perspective is important to understand the true benefit of interventions. Furthermore, considering both direct and indirect costs, as well as benefits, of this drug is vital because the economic profile of nab-paclitaxel would be improved.

Vichansavakul, Kittaya

251

Nab-paclitaxel: potential for the treatment of advanced pancreatic cancer  

PubMed Central

Advanced pancreatic adenocarcinoma is a deadly disease and is considered incurable. For the past two decades, gemcitabine remained the major chemotherapeutic drug with modest clinical benefit. Many chemotherapy and targeted agents were combined with gemcitabine but failed to demonstrate improvement in pancreatic cancer (PC) survival. Taxanes (paclitaxel, docetaxel) were introduced in the clinic as anti-microtubule agents and showed activity against PC cells in vitro; however, clinical efficacy was limited. Nab-paclitaxel (Abraxane) is an albumin-bound paclitaxel that has shown clinical activity in advanced breast and lung cancer. Recently, nab-paclitaxel was tested in a large Phase III clinical trial in combination with gemcitabine for the treatment of advanced PC. The data showed that the addition of nab-paclitaxel improved the response rate (7% in gemcitabine alone versus 23% in combination), progression-free survival (from 3.7 months to 5.5 months), and overall survival from 6.7 months to 8.5 months, compared to single agent gemcitabine. Through this review, we provide the preclinical and clinical progress in the development of nab-paclitaxel for the treatment of metastatic PC. PMID:24523592

Al-Hajeili, Marwan; Azmi, Asfar S; Choi, Minsig

2014-01-01

252

A new 2?,5?,10?,14?-tetraacetoxy-4(20),11-taxadiene (SIA) derivative overcomes paclitaxel resistance by inhibiting MAPK signaling and increasing paclitaxel accumulation in breast cancer cells.  

PubMed

Tumor resistance due to multiple mechanisms seriously hinders the efficacy of chemotherapy drugs such as paclitaxel. The most widely studied P-glycoprotein inhibitors still have limited ability to reverse resistance in the clinic. In this study, NPB304, a novel Sinenxan A (SIA) derivative, was found to significantly sensitize resistant breast cancer cells to paclitaxel in vitro and in vivo. Treatment with NPB304 increased paclitaxel-induced apoptosis in a p53-dependent manner through PARP cleavage. Importantly, NPB304 enhanced the antitumor effect of paclitaxel in resistant breast tumor xenografts in nude mice without significantly affecting weight loss. NPB304 regulated cell resistance through inhibition of MAPK pathway components, including p-ERK and p-p38. Moreover, NPB304 increased paclitaxel accumulation by affecting P-gp function. In addition to increasing Rhodamine 123 accumulation, NPB304 promoted bidirectional permeability but decreased the efflux ratio of paclitaxel in a Caco-2 monolayer model, thereby increasing the intracellular concentration of paclitaxel. Similarly, NPB304 increased the concentration of paclitaxel in the resistant tumor tissue. Hence, NPB304 is a novel compound that promotes the sensitization of resistant cells to paclitaxel through multiple mechanisms and has the potential for use in combination therapies to treat resistant breast cancer. PMID:25093335

Mei, Mei; Xie, Dan; Zhang, Yi; Jin, Jing; You, Feng; Li, Yan; Dai, Jungui; Chen, Xiaoguang

2014-01-01

253

Paclitaxel alters the evoked release of calcitonin gene-related peptide from rat sensory neurons in culture.  

PubMed

Peripheral neuropathy (PN) is a debilitating and dose-limiting side effect of treatment with the chemotherapeutic agent, paclitaxel. Understanding the effects of paclitaxel on sensory neuronal function and the signaling pathways which mediate these paclitaxel-induced changes in function are critical for the development of therapies to prevent or alleviate the PN. The effects of long-term administration of paclitaxel on the function of sensory neurons grown in culture, using the release of the neuropeptide calcitonin gene-related peptide (CGRP) as an endpoint of sensory neuronal function, were examined. Dorsal root ganglion cultures were treated with low (10 nM) and high (300 nM) concentrations of paclitaxel for 1, 3, or 5 days. Following paclitaxel treatment, the release of CGRP was determined using capsaicin, a TRPV1 agonist; allyl isothiocyanate (AITC), a TRPA1 agonist; or high extracellular potassium. The effects of paclitaxel on the release of CGRP were stimulant-, concentration-, and time-dependent. When neurons were stimulated with capsaicin or AITC, a low concentration of paclitaxel (10nM) augmented transmitter release, whereas a high concentration (300 nM) reduced transmitter release in a time-dependent manner; however, when high extracellular potassium was used as the evoking stimulus, all concentrations of paclitaxel augmented CGRP release from sensory neurons. These results suggest that paclitaxel alters the function of sensory neurons in vitro, and suggest that the mechanisms by which paclitaxel alters neuronal function may include functional changes in TRP channel activity. The described in vitro model will facilitate future studies to identify the signaling pathways by which paclitaxel alters neuronal sensitivity. PMID:24374060

Pittman, Sherry K; Gracias, Neilia G; Vasko, Michael R; Fehrenbacher, Jill C

2014-03-01

254

Molecular evidences for the chemosensitizing efficacy of liposomal curcumin in paclitaxel chemotherapy in mouse models of cervical cancer  

Microsoft Academic Search

The microtubule-targeting antineoplastic agent, paclitaxel, is highly efficacious against a wide spectrum of human cancers. However, dose-limiting toxicity and development of drug resistance limit its clinical application. Development of novel strategies that overcome chemoresistance and sensitize cancer cells to paclitaxel can enhance the therapeutic effect of this drug. We have previously shown that curcumin, a natural polyphenol, enhances paclitaxel-induced cytotoxicity

C N Sreekanth; S V Bava; E Sreekumar; R J Anto

2011-01-01

255

Effect of water content of organic solvent on microwave-assisted extraction efficiency of paclitaxel from plant cell culture  

Microsoft Academic Search

A microwave-assisted extraction (MAE) method was used to recover the anticancer agent paclitaxel from plant cell cultures,\\u000a and the extraction efficiency of the paclitaxel was determined using various organic solvents (acetone, chloroform, ethanol,\\u000a methanol, and methylene chloride) and solvent concentrations. Methanol provided the highest recovery of paclitaxel (?93%)\\u000a and resulted in the most severe rupturing of the biomass surface during

Ji-Yeon Lee; Jin-Hyun Kim

256

A mucoadhesive in situ gel delivery system for paclitaxel.  

PubMed

MUC1 gene encodes a transmembrane mucin glycoprotein that is overexpressed in human breast cancer and colon cancer. The objective of this study was to develop an in situ gel delivery system containing paclitaxel (PTX) and mucoadhesives for sustained and targeted delivery of anticancer drugs. The delivery system consisted of chitosan and glyceryl monooleate (GMO) in 0.33M citric acid containing PTX. The in vitro release of PTX from the gel was performed in presence and absence of Tween 80 at drug loads of 0.18%, 0.30%, and 0.54% (wt/wt), in Sorensen's phosphate buffer (pH 7.4) at 37 degrees C. Different mucin-producing cell lines (Calu-3>Caco-2) were selected for PTX transport studies. Transport of PTX from solution and gel delivery system was performed in side by side diffusion chambers from apical to basal (A-B) and basal to apical (B-A) directions. In vitro release studies revealed that within 4 hours, only 7.61% +/- 0.19%, 12.0% +/- 0.98%, 31.7% +/- 0.40% of PTX were released from 0.18%, 0.30%, and 0.54% drug-loaded gel formulation, respectively, in absence of Tween 80. However, in presence of surfactant (0.05% wt/vol) in the dissolution medium, percentages of PTX released were 28.1% +/- 4.35%, 44.2% +/- 6.35%, and 97.1% +/- 1.22%, respectively. Paclitaxel has shown a polarized transport in all the cell monolayers with B-A transport 2 to 4 times higher than in the A-B direction. The highest mucin-producing cell line (Calu-3) has shown the lowest percentage of PTX transport from gels as compared with Caco-2 cells. Transport of PTX from mucoadhesive gels was shown to be influenced by the mucin-producing capability of cell. PMID:16796370

Jauhari, Saurabh; Dash, Alekha K

2006-01-01

257

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. PMID:22172384

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

258

Sensitivity and mechanisms of taxol-resistant prostate adenocarcinoma cells to Vernonia amygdalina extract  

PubMed Central

Prostate cancer (PC) patients once Paclitaxel (TAX) treatment responsive later develop hormone refractory PC, thus becoming TAX-insensitive. This underscores the urgent need to develop novel anti-PC therapies. Vernonia amygdalina (VA) could be one such candidate agent. We have shown that androgen-independent PC-3 cells are sensitive to VA treatment in-vitro. VA extract (0.01, 0.1 and 1mg/ml) inhibited DNA synthesis by 12%, 45%, (P<0.05), and 73% (P<0.01) respectively. In contrast, TAX (0.01, 0.1, and 1?M) failed to significantly affect cell growth, suggesting TAX resistance. We tested molecular mechanisms which may lend to the observed PC-3 cell VA sensitivity/TAX resistance. Though both VA and TAX stimulated MAPK activity, VA’s induction was more intense, but transient, compared to TAX’s sustained action. NF-?B activation was inhibited on average by 50% by either 1mg/ml VA or 1 ?M TAX. VA extract caused 35% and 45% increases in c-Myc activity at 10 and 60 min intervals respectively, with the highest stimulation attained 1 hr after treatment. In contrast, similar levels were attained by TAX rapidly (within 5 min) and were sustained compared to the slow/multiphasic action of VA. VA extract treatments had no effect on AKT gene expression, while TAX treatments yielded a four-fold (P<0.01) increase; and P-glycoprotein (P-gp) activity was inhibited by VA and stimulated by TAX, compared to control (basal ATPase activity). This study shows that TAX-resistant PC-3 cells are sensitive to VA, perhaps explained by differential regulatory patterns of MAPK, c-Myc, AKT, and Pgp activities/expressions. PMID:23238229

Cameron, Keyuna S.; Howard, Carolyn B.; Izevbigie, Ernest B.; Hill, Brandon J.; Tchounwou, Paul B.

2012-01-01

259

Rationalization of paclitaxel insensitivity of yeast ?-tubulin and human ?III-tubulin isotype using principal component analysis  

PubMed Central

Background The chemotherapeutic agent paclitaxel arrests cell division by binding to the hetero-dimeric protein tubulin. Subtle differences in tubulin sequences, across eukaryotes and among ?-tubulin isotypes, can have profound impact on paclitaxel-tubulin binding. To capture the experimentally observed paclitaxel-resistance of human ?III tubulin isotype and yeast ?-tubulin, within a common theoretical framework, we have performed structural principal component analyses of ?-tubulin sequences across eukaryotes. Results The paclitaxel-resistance of human ?III tubulin isotype and yeast ?-tubulin uniquely mapped on to the lowest two principal components, defining the paclitaxel-binding site residues of ?-tubulin. The molecular mechanisms behind paclitaxel-resistance, mediated through key residues, were identified from structural consequences of characteristic mutations that confer paclitaxel-resistance. Specifically, Ala277 in ?III isotype was shown to be crucial for paclitaxel-resistance. Conclusions The present analysis captures the origin of two apparently unrelated events, paclitaxel-insensitivity of yeast tubulin and human ?III tubulin isotype, through two common collective sequence vectors. PMID:22849332

2012-01-01

260

Paclitaxel-induced hyposensitivity to nociceptive chemical stimulation in mice can be prevented by treatment with minocycline.  

PubMed

Development of peripheral neuropathy, which can present as painful neuropathy or loss of sensation, sometimes limit the use of paclitaxel in the treatment of solid tumors such as breast cancer. Previous studies reported development of thermal hyperalgesia in mice treated with paclitaxel. In this study an automated flinch detection system for the formalin test (20??l of 5% formalin injected subcutaneously into the paw dorsum) was used to evaluate chemical nociception in BALB/c mice treated with paclitaxel 2?mg/kg alone or coadministered with minocycline 50?mg/kg, intraperitoneally for 5 consecutive days. Reaction latency to thermal stimuli (hot-plate) was also measured. Injection of formalin resulted in biphasic paw flinches; phase 1 (1-9 minutes) and phase 2 (10-40 minutes). Treatment with paclitaxel reduced cumulative flinches in both phases 1 and 2 by 28% and 43%, respectively at day 7. However, treatment with paclitaxel also induced thermal hyperalgesia. Co-administration of paclitaxel with minocycline prevented development of both paclitaxel-induced hyposensitivity to chemical nociception and thermal hyperalgesia. In conclusion, the results indicate paclitaxel induces chemical hyposensitivity and thermal hyperalgesia in mice. Minocycline protected against paclitaxel-induced chemical hyposensitivity and thermal hyperalgesia, thus, providing further support of the usefulness of the drug in prevention of chemotherapy-induced neuropathy. PMID:25335491

Masocha, Willias

2014-01-01

261

Paclitaxel-induced hyposensitivity to nociceptive chemical stimulation in mice can be prevented by treatment with minocycline  

PubMed Central

Development of peripheral neuropathy, which can present as painful neuropathy or loss of sensation, sometimes limit the use of paclitaxel in the treatment of solid tumors such as breast cancer. Previous studies reported development of thermal hyperalgesia in mice treated with paclitaxel. In this study an automated flinch detection system for the formalin test (20??l of 5% formalin injected subcutaneously into the paw dorsum) was used to evaluate chemical nociception in BALB/c mice treated with paclitaxel 2?mg/kg alone or coadministered with minocycline 50?mg/kg, intraperitoneally for 5 consecutive days. Reaction latency to thermal stimuli (hot-plate) was also measured. Injection of formalin resulted in biphasic paw flinches; phase 1 (1–9 minutes) and phase 2 (10–40 minutes). Treatment with paclitaxel reduced cumulative flinches in both phases 1 and 2 by 28% and 43%, respectively at day 7. However, treatment with paclitaxel also induced thermal hyperalgesia. Co-administration of paclitaxel with minocycline prevented development of both paclitaxel-induced hyposensitivity to chemical nociception and thermal hyperalgesia. In conclusion, the results indicate paclitaxel induces chemical hyposensitivity and thermal hyperalgesia in mice. Minocycline protected against paclitaxel-induced chemical hyposensitivity and thermal hyperalgesia, thus, providing further support of the usefulness of the drug in prevention of chemotherapy-induced neuropathy. PMID:25335491

Masocha, Willias

2014-01-01

262

Mechanism of taxadiene synthase, a diterpene cyclase that catalyzes the first step of taxol biosynthesis in Pacific yew.  

PubMed

The first committed step in the formation of taxol has been shown to involve the cyclization of geranylgeranyl diphosphate to taxa-4(5),11(12)-diene. The formation of this endocyclic diterpene olefin isomer as the precursor of taxol was unexpected, since the exocyclic isomer, taxa-4(20),11(12)-diene, had been predicted as the initial product of the taxol pathway on the basis of metabolite co-occurrence. [1-2H2,20-2H3] and [20-2H3]geranylgeranyl diphosphates were employed as substrates with the partially purified taxadiene synthase from Pacific yew (Taxus brevifolia) stems to examine the possibility of a preliminary cyclization to taxa-4(20),11(12)-diene followed by isomerization to the more stable endocyclic double bond isomer. GLC-MS analysis of the derived taxa-4(5),11(12)-diene, via selected ion monitoring of the parent ion and the P-15 and C-ring fragment ions, compared to those of unlabeled standard, showed the olefin product to possess a deuterium enrichment essentially identical to that of the acyclic precursor, thus ruling out the putative isomerization step. With [4-2H2]geranylgeranyl diphosphate as substrate, similar product analysis established the enzymatically derived taxa-4(5),11(12)-diene to contain only one deuterium atom, consistent with direct formation from a taxenyl cation by deprotonation at C5. (+/-)-Casbene, (+/-)-verticillene, and (+/-)-taxa-4(20),11(12)-diene were tested as possible olefinic intermediates in taxa-4(5),11(12)-diene formation by a series of inhibition, trapping, and direct conversion experiments; no evidence was obtained that these exogenous olefins could serve as intermediates of the cyclization reaction. However, GLC-MS analysis of the taxadiene product derived by enzymatic cyclization of [1-3H]geranylgeranyl diphosphate in 2H2O indicated little incorporation of deuterium from the medium and suggested a rapid internal proton transfer in a tightly bound olefinic intermediate. Analysis of the enzymatic product generated from [10-2H1]geranylgeranyl diphosphate confirmed the intramolecular hydrogen transfer from C11 of a verticillyl intermediate to the C-ring of taxa-4(5),11(12)-diene. From these results, a stereochemical mechanism is proposed for the taxadiene synthase reaction involving the initial cyclization of geranylgeranyl diphosphate to a transient verticillyl cation intermediate, with transfer of the C11 alpha-proton to C7 to initiate transannular B/C-ring closure to the taxenyl cation, followed by deprotonation at C5 to yield the taxa-4(5),11(12)-diene product directly. PMID:8608134

Lin, X; Hezari, M; Koepp, A E; Floss, H G; Croteau, R

1996-03-01

263

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. PMID:19738417

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

264

Thermosensitive and Mucoadhesive Sol-Gel Composites of Paclitaxel/Dimethyl-?-Cyclodextrin for Buccal Delivery  

PubMed Central

The purpose of this study was to develop a buccal paclitaxel delivery system using the thermosensitive polymer Pluronic F127 (PF127) and the mucoadhesive polymer polyethylene oxide (PEO). The anticancer agent paclitaxel is usually used to treat ovarian, breast, and non-small-cell lung cancer. To improve its aqueous solubility, paclitaxel was incorporated into an inclusion complex with (2,6-di-O-methyl)-?-cyclodextrin (DM?CD). The formation of the paclitaxel inclusion complex was evaluated using various techniques, including x-ray diffractometry (XRD), Fourier-transform infrared (FT-IR) spectrophotometry, differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). Hydrogels were prepared using a cold method. Concentrations of 18, 20, and 23% (w/v) PF127 were dissolved in distilled water including paclitaxel and stored overnight in a refrigerator at 4°C. PEO was added at concentrations of 0.1, 0.2, 0.4, 0.8, and 1% (w/v). Each formulation included paclitaxel (0.5 mg/mL). The sol-gel transition temperature of the hydrogels was measured using the tube-inverting method. Drug release from the hydrogels was measured using a Franz diffusion cell containing pH 7.4 phosphate-buffered solution (PBS) buffer at 37°C. The cytotoxicity of each formulation was measured using the MTT assay with a human oral cancer cell (KB cell). The sol-gel transition temperature of the hydrogel decreased when PF127 was present and varied according to the presence of mucoadhesive polymers. The in vitro release was sustained and the release rate was slowed by the addition of the mucoadhesive polymer. The cytotoxicity of the blank formulation was low, although the drug-loaded hydrogel showed acceptable cytotoxicity. The results of our study suggest that the combination of a PF 127-based mucoadhesive hydrogel formulation and inclusion complexes improves the in vitro release and cytotoxic effect of paclitaxel. PMID:25275485

Kang, Bong-Seok; Ng, Choon Lian; Davaa, Enkhzaya; Park, Jeong-Sook

2014-01-01

265

Paclitaxel sensitivity of breast cancer cells requires efficient mitotic arrest and disruption of Bcl-xL/Bak interaction.  

PubMed

Taxanes are being used for the treatment of breast cancer. However, cancer cells frequently develop resistance to these drugs with the subsequent recurrence of the tumor. MDA-MB-231 and T-47D breast cancer cell lines were used to assess the effect of paclitaxel treatment on apoptosis and cell cycle, the possible mechanisms of paclitaxel resistance as well as the enhancement of paclitaxel-induced apoptosis based on its combination with phenylethyl isothiocyanate (PEITC). T-47D cells undergo apoptosis in response to paclitaxel treatment. The induction of apoptosis was associated with a robust mitotic arrest and the disruption of Bcl-xL/Bak interaction. By contrary, MDA-MB-231 cells were insensitive to paclitaxel-induced apoptosis and this was associated with a high percentage of cells that slip out of paclitaxel-imposed mitotic arrest and also with the maintenance of Bcl-xL/Bak interaction. The sequential treatment of MDA-MB-231 cells with PEITC followed by paclitaxel inhibited the slippage induced by paclitaxel and increased the apoptosis induction achieved with any of the drugs alone. In breast cancer tissues, high Bcl-xL expression was correlated with a shorter time of disease-free survival in patients treated with a chemotherapeutic regimen that contains paclitaxel, in a statistically significant way. Thus, resistance to paclitaxel in MDA-MB-231 cells is related to the inability to disrupt the Bcl-xL/Bak interaction and increased slippage. In this context, the combination of a drug that induces a strong mitotic arrest, such as paclitaxel, with another that inhibits slippage, such as PEITC, translates into increased apoptotic induction. PMID:22076480

Flores, M Luz; Castilla, Carolina; Ávila, Rainiero; Ruiz-Borrego, Manuel; Sáez, Carmen; Japón, Miguel A

2012-06-01

266

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. PMID:24831239

Kurtyka, Courtney A.; Chen, Lu; Cress, W. Douglas

2014-01-01

267

Synergistic interaction of paclitaxel and curcumin with cyclodextrin polymer complexation in human cancer cells.  

PubMed

The use of cytotoxic chemotherapic agents is the most common method for the treatment of metastatic cancers. Poor water solubility and low efficiency of chemotherapic agents are among the major hurdles of effective chemotherapy treatments. Curcumin and paclitaxel are well-known chemotherapic agents with poor water solubility and undesired side effects. In this study, a novel drug nanocarrier system was formulated by encapsulating curcumin and paclitaxel in poly(?-cyclodextrin triazine) (PCDT) for the therapy of four cancer models; ovarian, lung, prostate, and breast cancer. Cell viability and colony formation assays revealed enhanced curcumin cytotoxicity upon complexation. Annexin V apoptotic studies showed that the PCDT complexation improved curcumin induced apoptosis in human ovarian cancer cell lines A2780 and SKOV-3, human nonsmall cell lung carcinoma cell line H1299, and human prostate cancer line DU-145, while no significant effect was observed with paclitaxel/PCDT complexation. The bioactivity of combining curcumin and paclitaxel was also investigated. A synergism was found between curcumin and paclitaxel, particularly when complexed with PCDT on A2780, SKOV-3, and H1299 cancer cell lines. PMID:23730903

Boztas, Ali O; Karakuzu, Ozgur; Galante, Gabriela; Ugur, Zafer; Kocabas, Fatih; Altuntas, Cengiz Z; Yazaydin, A Ozgur

2013-07-01

268

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

269

Cytotoxicity of paclitaxel in breast cancer is due to chromosome missegregation on multipolar spindles  

PubMed Central

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, the majority of 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 due to chromosome missegregation on highly abnormal, multipolar spindles. This mechanistic insight may be used to improve selection of future anti-mitotic 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.

2014-01-01

270

A Phase I study of capecitabine, carboplatin, and paclitaxel with external beam radiation therapy for esophageal carcinoma  

Microsoft Academic Search

Purpose: Concurrent chemotherapy and radiation therapy (RT) are used to treat patients with esophageal cancer. The optimal combination of chemotherapeutic agents with RT is undefined. We evaluated a combination of capecitabine, carboplatin, and paclitaxel with RT in a phase I study. Methods and Materials: Patients with squamous cell carcinoma or adenocarcinoma of the esophagus initially received capecitabine, carboplatin, and paclitaxel

Brian G.. Czito; Chris R. Kelsey; Herbert I. Hurwitz; Chris G. Willett; Michael A. Morse; Gerard C. Blobe; Nishan H. Fernando; Thomas A. D’Amico; David H. Harpole; Wanda R. N. Honeycutt; Daohai Yu; Johanna C. Bendell

2007-01-01

271

Phase II study with paclitaxel for the treatment of advanced inoperable non-small cell lung cancer  

Microsoft Academic Search

Paclitaxel is a plant product isolated from the bark of the Western yew (Taxus brevifolia) that promotes the formation and stabilization of microtubules. This leads to growth arrest in the G2\\/M phase of the cell cycle. Paclitaxel has demonstrated significant antineoplastic activity in different tumor types, most notably in ovarian and breast carcinoma. In two Phase II trials (Eastern Cooperative

Ulrich Gatzemeier; Marlene Heckmayr; Renate Neuhauss; Ingrid Schlüter; Joachim V. Pawel; Horst Wagner; Andreas Dreps

1995-01-01

272

Use of a cholesterol-rich emulsion that binds to low-density lipoprotein receptors as a vehicle for paclitaxel.  

PubMed

A cholesterol-rich emulsion (LDE) is taken up by malignant cells which over-express low-density lipoprotein (LDL) receptors and thus may be used as a carrier for drugs directed against neoplastic cells. In this study, we associated the antineoplastic agent paclitaxel to LDE and analysed the new formulation's incorporation efficiency, chemical and physical stability, cellular uptake and cytostatic activity against a neoplastic cell line and the acute toxicity to rats. A paclitaxel incorporation efficiency of approximately 75% was achieved when paclitaxel was mixed with LDE at a 6:1 lipid-to-drug molar ratio. The association of paclitaxel with LDE increased by 54% the mean diameter of the emulsion particles but did not damage the paclitaxel chemical structure as analysed by HPLC. Results from gradient ultracentrifugation and Sephadex G25 gel filtration indicated that the binding of the drug to the emulsion was stable. It was shown that the cellular uptake and the cytotoxic activity of LDE-paclitaxel by a neoplastic cell line (NCI-H292 cells) was indeed mediated by the LDL receptors. The antiproliferative activity of LDE-paclitaxel against NCI-H292 cells was less than that of a commercial paclitaxel preparation (50% inhibitory concentration, IC50 = 2.60 and 0.45 microM, respectively). This difference, however, can be ascribed to the in-vitro anti-proliferative activity of the commercial paclitaxel vehicle Cremophor EL; when Cremophor EL was added to the cultures with LDE-paclitaxel, the IC50 value was reduced to 0.45 microM, attaining that of the commercial paclitaxel preparation. The tolerability of LDE-paclitaxel in rats was remarkable, such that its lethal dose (LD50) was ten-fold greater than that of the commercial formulation (LD50 = 324 and 31.8 mg kg(-1), respectively). Therefore, LDE-paclitaxel association is stable and the cytostatic activity of the drug is preserved while its toxicity to rats is small. By diminishing the side effects and directing paclitaxel to neoplastic tissues, LDE may be useful as adjuvant in chemotherapy with this drug. PMID:12078992

Rodrigues, Debora G; Covolan, Cristiane C; Coradi, Silvana T; Barboza, Renato; Maranhão, Raul C

2002-06-01

273

Extracellular biosynthesis of gadolinium oxide (Gd2O3) nanoparticles, their biodistribution and bioconjugation with the chemically modified anticancer drug taxol  

PubMed Central

Summary As a part of our programme to develop nanobioconjugates for the treatment of cancer, we first synthesized extracellular, protein-capped, highly stable and well-dispersed gadolinium oxide (Gd2O3) nanoparticles by using thermophilic fungus Humicola sp. The biodistribution of the nanoparticles in rats was checked by radiolabelling with Tc-99m. Finally, these nanoparticles were bioconjugated with the chemically modified anticancer drug taxol with the aim of characterizing the role of this bioconjugate in the treatment of cancer. The biosynthesized Gd2O3 nanoparticles were characterized by UV–vis spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoemission spectroscopy (XPS). The Gd2O3–taxol bioconjugate was confirmed by UV–vis spectroscopy and fluorescence microscopy and was purified by using high performance liquid chromatography (HPLC). PMID:24778946

Khan, Shadab Ali; Gambhir, Sanjay

2014-01-01

274

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. PMID:18829396

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

2010-01-01

275

Praziquantel synergistically enhances paclitaxel efficacy to inhibit cancer cell growth.  

PubMed

The major challenges we are facing in cancer therapy with paclitaxel (PTX) are the drug resistance and severe side effects. Massive efforts have been made to overcome these clinical challenges by combining PTX with other drugs. In this study, we reported the first preclinical data that praziquantel (PZQ), an anti-parasite agent, could greatly enhance the anticancer efficacy of PTX in various cancer cell lines, including PTX-resistant cell lines. Based on the combination index value, we demonstrated that PZQ synergistically enhanced PTX-induced cell growth inhibition. The co-treatment of PZQ and PTX also induced significant mitotic arrest and activated the apoptotic cascade. Moreover, PZQ combined with PTX resulted in a more pronounced inhibition of tumor growth compared with either drug alone in a mouse xenograft model. We tried to investigate the possible mechanisms of this synergistic efficacy induced by PZQ and PTX, and we found that the co-treatment of the two drugs could markedly decrease expression of X-linked inhibitor of apoptosis protein (XIAP), an anti-apoptotic protein. Our data further demonstrated that down-regulation of XIAP was required for the synergistic interaction between PZQ and PTX. Together, this study suggested that the combination of PZQ and PTX may represent a novel and effective anticancer strategy for optimizing PTX therapy. PMID:23251610

Wu, Zhen Hua; Lu, Ming-ke; Hu, Long Yu; Li, Xiaotong

2012-01-01

276

Strategy of directly employing paclitaxel to construct vesicles.  

PubMed

A class of aza-arm modified ?-cyclodextrins were found to be able to trap paclitaxel (PTX), an effective but strongly hydrophobic anticancer drug, to form novel "supramolecular amphiphiles", which can further self-assemble into vesicular structures in aqueous solution. The obtained vesicles were characterized in detail by transmission electron microscopy (TEM), scanning electron microscopy (SEM), cryogenic transmission electron microscopy (cryo-TEM), and dynamic light scattering (DLS). The mechanism of the vesicular formation was suggested on the basis of the experimental results of nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and thermal analysis. The effects to the vesicular formation by changing the host molecules and solvents were also studied. The vesicles will disappear upon the introduction of Cu(2+) into the vesicular system, during the procedure of which, PTX will be released meanwhile. We believe that our research will provide a new strategy of directly employing special drugs to construct microvehicles to carry other targeted molecules. PMID:23194107

Sun, Tao; Yan, Hui; Liu, Guangcun; Hao, Jingcheng; Su, Jie; Li, Shangyang; Xing, Pengyao; Hao, Aiyou

2012-12-20

277

Polymerizable disulfide paclitaxel prodrug for controlled drug delivery.  

PubMed

A polymerizable disulfide paclitaxel (PTX) prodrug was synthesized by the consequential esterification reactions of 3,3'-dithiodipropionic acid (DTPA), a disulfide compound containing two active carboxyl groups, with 2-hydroxyethyl methacrylate (HEMA) and PTX. The structure of the prodrug was confirmed by (1)H NMR characterization. Then, the polymerizable prodrug was copolymerized with poly(ethylene glycol) methyl ether methacrylate (PEGMEA) to obtain a copolymer with hydrophilic PEG side chains and PTX covalently linked onto the backbone via disulfide bonds. The loading content of PTX was 23%. In aqueous solution, this copolymer prodrug could self-assemble into micelles, with hydrophobic PTX as the cores and hydrophilic PEG-segment as the shells. In vitro cell assay demonstrated that this copolymer prodrug showed more apparent cytotoxicity to cancer cells than to human normal cells. After incubation for 48h, the cell viability of HEK-293 cells (human embryo kidney cells) at 0.1?g/mL PTX still remained more than 90%, however, that of HeLa cells (human cervical cancer cells) decreased to 52%. PMID:25280719

Ding, Yi; Chen, Wulian; Hu, Jianhua; Du, Ming; Yang, Dong

2014-11-01

278

MicroRNA21 inhibitor sensitizes human glioblastoma cells U251 (PTEN-mutant) and LN229 (PTEN-wild type) to taxol  

Microsoft Academic Search

BACKGROUND: Substantial data indicate that the oncogene microRNA 21 (miR-21) is significantly elevated in glioblastoma multiforme (GBM) and regulates multiple genes associated with cancer cell proliferation, apoptosis, and invasiveness. Thus, miR-21 can theoretically become a target to enhance the chemotherapeutic effect in cancer therapy. So far, the effect of downregulating miR-21 to enhance the chemotherapeutic effect to taxol has not

Yu Ren; Xuan Zhou; Mei Mei; Xu-Bo Yuan; Lei Han; Guang-Xiu Wang; Zhi-Fan Jia; Peng Xu; Pei-Yu Pu; Chun-Sheng Kang

2010-01-01

279

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. PMID:24520227

Kim, Hee Jung; Yim, Ga Won; Nam, Eun Ji

2014-01-01

280

Quasi-Complete Response of Classic Kaposi's Sarcoma Treated with Weekly Paclitaxel  

PubMed Central

Classic Kaposi's sarcoma (CKS) is a subtype that traditionally occurs in elderly HIV-negative males of Mediterranean origin. Patients with CKS characteristically present with skin lesions in the distal extremities. Involvement of the viscera is uncommon but may occur in the late stages of the disease. Patients with extensive KS can be treated with systemic chemotherapy. A number of drugs approved for treatment of AIDS-associated KS, especially Paclitaxel, have activity against CKS after failure of prior therapy. We report a patient treated with weekly Paclitaxel, as initial chemotherapy, for CKS presenting with multiple visceral involvement and having a contraindication for Bleomycin. The patient had quasi-complete response after three months of chemotherapy suggesting that weekly Paclitaxel might be effective as a first-line therapy for classical type KS with visceral involvement. PMID:23476845

Benbrahim, Zineb; Arifi, Samia; Benhammane, Hafida; Inani, Kaoutar; Gallouj, Salim; Meziane, Meriem; Mernissi, Fatima Zahra; Mellas, Nawfel; El Mesbahi, Omar

2013-01-01

281

The effect of paclitaxel on the radiosensitivity of gynecological tumor cells  

Microsoft Academic Search

Background  Paclitaxel, a natural product from Taxus brevifolia, is a microtubule stabilizing agent, which has been shown to block different\\u000a cells in the G2\\/M phase of the cell cycle and consequently, to modulate their radioresponsiveness. Our aim was to test the\\u000a cytotoxic and radiosensitizing potential of paclitaxel, with respect to different gynecological tumors with varying radiosensitivities.\\u000a \\u000a \\u000a \\u000a Material and Method  We performed clonogenic

M. Rave-Fränk; H. Meden; A. Jäschke; A. Tänzer; O. Boghun; R. Fietkau

1997-01-01

282

Androgen and taxol cause cell type-specific alterations of centrosome and DNA organization in androgen-responsive LNCaP and androgen-independent DU145 prostate cancer cells  

NASA Technical Reports Server (NTRS)

We investigated the effects of androgen and taxol on the androgen-responsive LNCaP and androgen-independent DU145 prostate cancer cell lines. Cells were treated for 48 and 72 h with 0.05-1 nM of the synthetic androgen R1881 and with 100 nM taxol. Treatment of LNCaP cells with 0.05 nM R1881 led to increased cell proliferation, whereas treatment with 1 nM R1881 resulted in inhibited cell division, DNA cycle arrest, and altered centrosome organization. After treatment with 1 nM R1881, chromatin became clustered, nuclear envelopes convoluted, and mitochondria accumulated around the nucleus. Immunofluorescence microscopy with antibodies to centrosomes showed altered centrosome structure. Although centrosomes were closely associated with the nucleus in untreated cells, they dispersed into the cytoplasm after treatment with 1 nM R1881. Microtubules were only faintly detected in 1 nM R1881-treated LNCaP cells. The effects of taxol included microtubule bundling and altered mitochondria morphology, but not DNA organization. As expected, the androgen-independent prostate cancer cell line DU145 was not affected by R1881. Treatment with taxol resulted in bundling of microtubules in both cell lines. Additional taxol effects were seen in DU145 cells with micronucleation of DNA, an indication of apoptosis. Simultaneous treatment with R1881 and taxol had no additional effects on LNCaP or DU145 cells. These results suggest that LNCaP and DU145 prostate cancer cells show differences not only in androgen responsiveness but in sensitivity to taxol as well. Copyright 2000 Wiley-Liss, Inc.

Schatten, H.; Ripple, M.; Balczon, R.; Weindruch, R.; Chakrabarti, A.; Taylor, M.; Hueser, C. N.

2000-01-01

283

End-binding protein 1 stimulates paclitaxel sensitivity in breast cancer by promoting its actions toward microtubule assembly and stability.  

PubMed

Paclitaxel is a microtubule-targeting agent widely used for the treatment of many solid tumors. However, patients show variable sensitivity to this drug, and effective diagnostic tests predicting drug sensitivity remain to be investigated. Herein, we show that the expression of end-binding protein 1 (EB1), a regulator of microtubule dynamics involved in multiple cellular activities, in breast tumor tissues correlates with the pathological response of tumors to paclitaxel-based chemotherapy. In vitro cell proliferation assays reveal that EB1 stimulates paclitaxel sensitivity in breast cancer cell lines. Our data further demonstrate that EB1 increases the activity of paclitaxel to cause mitotic arrest and apoptosis in cancer cells. In addition, microtubule binding affinity analysis and polymerization/depolymerization assays show that EB1 enhances paclitaxel binding to microtubules and stimulates the ability of paclitaxel to promote microtubule assembly and stabilization. These findings thus reveal EB1 as a critical regulator of paclitaxel sensitivity and have important implications in breast cancer chemotherapy. PMID:24748116

Luo, Youguang; Li, Dengwen; Ran, Jie; Yan, Bing; Chen, Jie; Dong, Xin; Liu, Zhu; Liu, Ruming; Zhou, Jun; Liu, Min

2014-06-01

284

A randomized phase II trial comparing every 3-weeks carboplatin\\/paclitaxel with every 3-weeks carboplatin and weekly paclitaxel in advanced non-small cell lung cancer  

Microsoft Academic Search

Background: The optimal schedule of taxane administration has been an area of active interest in several recent clinical trials. Methods: To address a pure schedule question, we randomized 161 patients with advanced stage IIIB or IV non-small-cell lung cancer (NSCLC) to either paclitaxel 225 mg\\/m2 every 3 weeks · 4 cycles or 75 mg\\/m2\\/week · 12 (cumulative dose on each

M. A. Socinski; A. Ivanova; K. Bakri; J. Wall; M. Q. Baggstrom; T. A. Hensing; A. Mears; M. Tynan; J. Beaumont; A. H. Peterman; H. B. Niell

2005-01-01

285

Validated HPLC Method for the Determination of Paclitaxel-related Substances in an Intravenous Emulsion Loaded with a Paclitaxel-Cholesterol Complex  

PubMed Central

A high-performance liquid chromatography method was developed for the determination of related substances in an intravenous emulsion loaded with a paclitaxel–cholesterol complex. The separation was achieved using Agilent Eclipse XDB-C18 column (150×4.6 mm, 3.5 ?m), which was kept at 40°. The gradient mobile phase consisted of acetonitrile and water with a flow rate of 1.2 ml/min. The ultraviolet detection wavelength was set at 227 nm. The preparation of the sample solution began with the addition of anhydrous sodium sulphate to break the emulsion. Then, methanol and ethyl ether were added to pick up the drug and remove the accessories of the emulsion by extraction and centrifugation. Finally, paclitaxel was enriched by a nitrogen blow method and resolved with a mixture of methanol:glacial acetic acid (200:1). The method was proven to be selective, sensitive, robust, linear, repeatable, accurate and suitable for the determination of paclitaxel-related substances in the emulsion formulations, and the major degradation products in the potential pharmaceutical product were 7-epipaclitaxel and 10-deacetylpaclitaxel. PMID:24591742

Xia, X. J.; Peng, J.; Zhang, P. X.; Jin, D. J.; Liu, Y. L.

2013-01-01

286

Paclitaxel and TRAIL Synergize to Kill Paclitaxel-resistant Small Cell Lung Cancer Cells through a Caspase-independent Mechanism Mediated through AIF  

PubMed Central

Background Small cell lung cancer (SCLC) is the most aggressive form of lung cancer with poor disease outcome. Chemotherapeutic agent paclitaxel (PA) is commonly used as a second-line treatment in SCLC, but response rates are low. Materials and Methods 86M1 SCLC cells were treated in the presence or absence of Paclitaxel and TRAIL or the combination for 24 hours. Western blot analysis was utilized to examine protein expression, cell surface protein expression and membrane integrity were elucidated by flow cytometry, and immunofluorescence microscopy was used to demonstrate translocation of proteins to the cell nucleus. Results Human 86M1 SCLC cells were found to be resistant to PA killing in vitro. This resistance is mediated by up-regulation of pro-survival protein BCL-xl. However, PA also increases surface expression of death receptors 4 and 5 (DR4 and DR5, respectively). The death receptors’ ligand increased SCLC killing by PA through an apparent caspase-independent route involving activation/translocation of AIF. Conclusion The addition of TRAIL to PA can potentiate apoptosis in a relatively PA-resistant SCLC line (specifically 86M1 cells). More importantly, we are the first to report an active method of resistance to paclitaxel in SCLC via BCL-xl up-regulation. PMID:21965726

HUNTER, TERRI B.; MANIMALA, NEIL J.; LUDDY, KIMBERLY A.; CATLIN, TRACY; ANTONIA, SCOTT J.

2014-01-01

287

Taxol-stabilized microtubules promote the formation of filaments from unmodified full-length Tau in vitro  

PubMed Central

Tau is a neuronal protein that stabilizes the microtubule (MT) network, but it also forms filaments associated with Alzheimer's disease. Understanding Tau–MT and Tau–Tau interactions would help to establish Tau function in health and disease. For many years, literature reports on Tau–MT binding behavior and affinity have remained surprisingly contradictory (e.g., 10-fold variation in Tau–MT affinity). Tau–Tau interactions have also been investigated, but whether MTs might affect Tau filament formation is unknown. We have addressed these issues through binding assays and microscopy. We assessed Tau–MT interactions via cosedimentation and found that the measured affinity of Tau varies greatly, depending on the experimental design and the protein concentrations used. To investigate this dependence, we used fluorescence microscopy to examine Tau–MT binding. Strikingly, we found that Taxol-stabilized MTs promote Tau filament formation without characterized Tau-filament inducers. We propose that these novel Tau filaments account for the incongruence in Tau–MT affinity measurements. Moreover, electron microscopy reveals that these filaments appear similar to the heparin-induced Alzheimer's model. These observations suggest that the MT-induced Tau filaments provide a new model for Alzheimer's studies and that MTs might play a role in the formation of Alzheimer's-associated neurofibrillary tangles. PMID:23087208

Duan, Aranda R.; Goodson, Holly V.

2012-01-01

288

Evaluation of combined bevacizumab and intraperitoneal carboplatin or paclitaxel therapy in a mouse model of ovarian cancer  

Microsoft Academic Search

Purpose  To evaluate the pharmacokinetics of bevacizumab following IP and IV administration, and to investigate combined bevacizumab\\u000a therapy (IP or IV) with IP paclitaxel or carboplatin in a mouse model of ovarian cancer.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  Bevacizumab pharmacokinetics were investigated following IV or IP dosing, and mice bearing peritoneal A2780 xenografts were\\u000a treated with vehicle, IV or IP bevacizumab, IP paclitaxel, IP paclitaxel with

Dhaval K. Shah; Jean Veith; Ralph J. Bernacki; Joseph P. Balthasar

289

Acquisition of Paclitaxel Resistance Is Associated With a More Aggressive and Invasive Phenotype in Prostate Cancer  

PubMed Central

Drug resistance is a major limitation to the successful treatment of advanced prostate cancer (PCa). Patients who have metastatic, castration-resistant PCa (mCRPC) are treated with chemotherapeutics. However, these standard therapy modalities culminate in the development of resistance. We established paclitaxel resistance in a classic, androgen-insensitive mCRPC cell line (DU145) and, using a suite of molecular and biophysical methods, characterized the structural and functional changes in vitro and in vivo that are associated with the development of drug resistance. After acquiring paclitaxel-resistance, cells exhibited an abnormal nuclear morphology with extensive chromosomal content, an increase in stiffness, and faster cytoskeletal remodeling dynamics. Compared with the parental DU145, paclitaxel-resistant (DU145-TxR) cells became highly invasive and motile in vitro, exercised greater cell traction forces, and formed larger and rapidly growing tumors in mouse xenografts. Furthermore, DU145-TxR cells showed a discrete loss of keratins but a distinct gain of ZEB1, Vimentin and Snail, suggesting an epithelial-to-mesenchymal transition. These findings demonstrate, for the first time, that paclitaxel resistance in PCa is associated with a trans-differentiation of epithelial cell machinery that enables more aggressive and invasive phenotype and portend new strategies for developing novel biomarkers and effective treatment modalities for PCa patients. PMID:23192682

Kim, John J.; Yin, Bo; Christudass, Christhunesa S.; Terada, Naoki; Rajagopalan, Krithika; Fabry, Ben; Lee, Danielle Y.; Shiraishi, Takumi; Getzenberg, Robert H.; Veltri, Robert W.; An, Steven S.; Mooney, Steven M.

2014-01-01

290

Paclitaxel coating of the luminal surface of hemodialysis grafts with effective suppression of  

E-print Network

on the outer surface. Methods: A peristaltic pump and a double-solvent (water and acetone) system were used of hemodialysis grafts is effective in suppressing neointimal hyperplasia in the graft and vascular anastomosis). Compared with the control group, paclitaxel inner-coated vascular grafts significantly suppressed

Park, Jong-Sang

291

Molecular Mechanisms of Paclitaxel Resistance and Resveratrol Sensitivity in MDA-MB-231 Breast Cancer Cells  

E-print Network

Molecular Mechanisms of Paclitaxel Resistance and Resveratrol Sensitivity in MDA-MB-231 Breast to the parent line. It has been suggested that the polyphenol natural compound, resveratrol, which has been sensitive to resveratrol treatment. We observed that treatment with 10-100 µM concentrations of resveratrol

Zhou, Yaoqi

292

Cisplatin and paclitaxel target significant long noncoding RNAs in laryngeal squamous cell carcinoma.  

PubMed

The objectives of this study were to identify specific long noncoding RNAs (lncRNAs) in laryngeal squamous cell carcinoma (LSCC) and to clarify the function of cisplatin and paclitaxel on the confirmed laryngeal cancer lncRNAs. Fifty-four pairs of laryngeal tumor and adjacent normal tissue were collected. Candidate lncRNAs were searched in authorized databases. The significant lncRNAs were identified and confirmed through high-output real-time PCR. Chemotherapy assay evaluated the influences of cisplatin and paclitaxel on the significant lncRNAs. Thirty-seven cancer-related candidate lncRNAs were selected. Three up-expressed and two down-expressed significant lncRNAs were identified and confirmed. The expressions of lncRNA CDKN2B-AS1, HOTAIR and MALAT1 were dramatically reduced with the increasing concentration of cisplatin and paclitaxel and also lengthening of the treatment duration. Cisplatin and paclitaxel have target function on significant lncRNAs in LSCC, which presents novel molecular targets to cure LSCC patients and also leads an orientation for developing new drugs. PMID:25257554

Chen, Hui; Xin, Yuan; Zhou, Liang; Huang, Jia-Meng; Tao, Lei; Cheng, Lei; Tian, Jie

2014-11-01

293

Establishment of opioid-induced rewarding effects under oxaliplatin- and Paclitaxel-induced neuropathy in rats.  

PubMed

The rewarding effects of ?-receptor agonists can be suppressed under several pain conditions. We recently showed that clinically used ?-receptor agonists possess efficacies for relieving the neuropathic pain induced by chemotherapeutic drug in rats; however, it is possible that the use of ?-receptor agonists may trigger the rewarding effects even under chemotherapeutic drug-induced neuropathic pain. Nevertheless, no information is available regarding whether ?-receptor agonists produce psychological dependence under chemotherapeutic drug-induced neuropathic pain. Therefore, we examined the effects of neuropathy induced by chemotherapeutic drugs on the rewarding effects of morphine, oxycodone, and fentanyl in rats. Repeated treatment with oxaliplatin or paclitaxel produced neuropathy as measured by the von Frey test. Rewarding effects produced by antinociceptive doses of ?-receptor agonists were not suppressed under oxaliplatin- or paclitaxel-induced neuropathy. Furthermore, the morphine-induced increase in the release of dopamine from the nucleus accumbens, which is a critical step in the rewarding effects of ?-receptor agonists, was not altered in paclitaxel-treated rats. These results suggest that the rewarding effects of ?-receptor agonists can still be established under oxaliplatin- or paclitaxel-induced neuropathic pain. Therefore, patients should be carefully monitored for psychological dependence on ?-receptor agonists when they are used to control chemotherapeutic drug-induced neuropathic pain. PMID:25141998

Mori, Tomohisa; Kanbara, Tomoe; Harumiya, Masato; Iwase, Yoshiyuki; Masumoto, Aki; Komiya, Sachiko; Nakamura, Atsushi; Shibasaki, Masahiro; Kanemasa, Toshiyuki; Sakaguchi, Gaku; Suzuki, Tsutomu

2014-09-20

294

Improved paclitaxel and baccatin III production in suspension cultures of Taxus media.  

PubMed

A cell suspension culture of Taxus media was established from a stable callus line of this species. The growth rate and production of paclitaxel and baccatin III of this cell suspension were significantly increased during the shake flask culture in its respective optimum media for cell growth and product formation, which were selected after assaying 24 different culture media. The highest yields of paclitaxel (2.09 mg L(-1)) and baccatin III (2.56 mg L(-1)) in the production medium rose (factors of 7.0 and 3.0, respectively) in the presence of methyljasmonate (220 microg g(-1) FW). When the elicitor was added together with mevalonate (0.38 mM) and N-benzoylglycine (0.2 mM), the increase in the yields of paclitaxel and baccatin III was even higher (factors of 8.3 and 4.0, respectively). Thereafter, a two-stage culture for cell suspension was carried out using a 5-l stirred bioreactor running for 36 days, the first stage being in the cell growth medium until cells entered their stationary growth phase (12 days) and the second stage being in the production medium supplemented with the elicitor and two putative precursors in the concentrations indicated above. Under these conditions, 21.12 mg L(-1) of paclitaxel and 56.03 mg L(-1) of baccatin III were obtained after 8 days of culture in the production medium. PMID:12052053

Cusidó, Rosa M; Palazón, Javier; Bonfill, Mercedes; Navia-Osorio, Alberto; Morales, Carmen; Piñol, M Teresa

2002-01-01

295

[A case of advanced breast cancer successfully treated with paclitaxel and toremifene therapy].  

PubMed

We report a case of advanced breast cancer with skin ulceration and bleeding (T4bN3bM0: Stage IIIC) achieving a significant improvement of QOL by toremifene and paclitaxel therapy. The patient was a 38-year-old woman with slight anemia who had ulcerative breast lump with skin ulcer. A core needle biopsy for breast tumor led to a diagnosis of an invasive ductal carcinoma positive for estrogen receptor and progesteron receptor, and negative for HER2/neu protein expression. She received 6 cycles of tri-weekly FEC (C: 500 mg, E: 60 mg, F: 500 mg/m2) and 16 cycles of weekly paclitaxel (80 mg/m2) with toremifene (120 mg/day). The anemia and the bleeding from the tumor disappeared after FEC chemotherapy. The response for breast tumor after paclitaxel and toremifene therapy was evaluated as partial response, and the infraclavicular, subpectoral, and interpectoral lymph nodes metastasis disappeared. Muscle-preserving radical mastectomy (Bt + Ax: Auchincloss) with skin transplantation was performed. She had no recurrence during one year after the operation. Paclitaxel and Toremifene therapy was effective for advanced breast tumor, and can improve a patient QOL and the clinical outcomes in Stage IIIC advanced breast cancer. PMID:19106576

Sakurai, Kenichi; Enomoto, Katsuhisa; Tani, Mayumi; Kitajima, Akira; Amano, Sadao; Shiono, Motomi

2008-11-01

296

Screening of the needles of different yew species and cultivars for paclitaxel and related taxoids  

Microsoft Academic Search

The needles of several yew species and cultivars were analysed by high-pressure liquid chromatography for paclitaxel, 10-deacetylpaclitaxel, cephalomannine, baccatin III, 10-deacetylbaccatin III and brevifoliol. About 750 samples were collected from five different locations in the Netherlands and the UK. The results of this screening show a large variation in taxane content between the different species and cultivars. The content of

Erik L. M van Rozendaal; Gerrit P Lelyveld; Teris A van Beek

2000-01-01

297

Activity of Gemcitabine in Patients with Advanced Ovarian Cancer: Responses Seen Following Platinum and Paclitaxel  

Microsoft Academic Search

Thirty-eight women with epithelial ovarian cancer were treated with gemcitabine, a new antimetabolite. All had previously received platinum, and 27 had also received paclitaxel. Four patients had a partial response giving a response rate of 13% in assessable patients (n= 31) and 11% for all patients entered. Additionally, 6 patients had stable disease with >50% reduction in CA-125 for at

Jeremy D. Shapiro; Michael J. Millward; Danny Rischin; Michael Michael; Vicki Walcher; Prudence A. Francis; Guy C. Toner

1996-01-01

298

Coating with paclitaxel improves graft survival in a porcine model of haemodialysis graft stenosis  

Microsoft Academic Search

Background. Most commonly resulting from intimal hyperplasia at the venous anastomosis, stenosis leading to thrombosis is a major cause of failure of polytetra- fluoroethylene (PTFE) dialysis grafts. We recently reported that coating haemodialysis grafts with pacli- taxel could reduce neointimal hyperplasia. This study tested whether paclitaxel-coating could prolong graft survival in a porcine model. Methods. PTFE grafts were double-coated with

Byung Ha Lee; Jung Eun Lee; Kwang Woong Lee; Hye Yeong Nam; Hyun Jung Jeon; Young Ju Sung; Jong Sung Kim; Hyun Jung Lim; Jong-sang Park; Jai Young Ko; Dae Joong Kim

2007-01-01

299

Polymeric nanoparticles for the intracellular delivery of paclitaxel in lung and breast cancer  

NASA Astrophysics Data System (ADS)

Nanoparticles are useful for addressing many of the difficulties encountered when administering therapeutic compounds. Nanoparticles are able to increase the solubility of hydrophobic drugs, improve pharmacokinetics through sustained release, alter biodistribution, protect sensitive drugs from low pH environments or enzymatic alteration, and, in some cases, provide targeting of the drug to the desired tissues. The use of functional nanocarriers can also provide controlled intracellular delivery of a drug. To this end, we have developed functional pH-responsive expansile nanoparticles for the intracellular delivery of paclitaxel. The pH-responsiveness of these nanoparticles occurs due to a hydrophobic to hydrophilic transition of the polymer occurring under mildly acidic conditions. These polymeric nanoparticles were systematically evaluated for the delivery of paclitaxel in vitro and in vivo to improve local therapy for lung and breast cancers. Nanoparticles were synthesized using a miniemulsion polymerization process and were subsequently characterized and found to swell when exposed to acidic environments. Paclitaxel was successfully encapsulated within the nanoparticles, and the particles exhibited drug release at pH 5 but not at pH 7.4. In addition, the uptake of nanoparticles was observed using flow cytometry, and the anticancer efficacy of the paclitaxel-loaded nanoparticles was measured using cancer cell lines in vitro. The potency of the paclitaxel-loaded nanoparticles was close to that of free drug, demonstrating that the drug was effectively delivered by the particles and that the particles could act as an intracellular drug depot. Following in vitro characterization, murine in vivo studies demonstrated the ability of the paclitaxel-loaded responsive nanoparticles to delay recurrence of lung cancer and to prevent establishment of breast cancer in the mammary fat pads with higher efficacy than paclitaxel alone. In addition, the ability of nanoparticles to migrate up to 40 cm through lymphatic channels to local lymph nodes was demonstrated using near infrared imaging in a large animal model. Continued investigation of functional nanoparticles, like the system described here for lung and breast cancer, will facilitate the development of new materials that meet the varied and demanding needs in chemotherapy, and may afford new treatment options for the local and metastatic control of many forms of cancer.

Zubris, Kimberly Ann Veronica

300

Digitoxin activates EGR1 and synergizes with paclitaxel on human breast cancer cells  

PubMed Central

Background: Numerous studies have suggested that digitalis derivatives promise to be superior to existing adjuvant therapy for breast cancer as to effects and side-effects. In the present study, we have used gene expression analysis to determine the molecular action of digitoxin on breast cancer cells and assessed digitoxin’s ability to synergize with the chemotherapy agent paclitaxel with respect to inhibition of cell proliferation Materials and Methods: We treated (Her2 overexpressing, ER low) MDA-MB-453 human breast cancer cells with digitoxin at four doses {20 ng/ml (26 nM) to 1 ?g/ml} and collected RNA at 6 h and 24 h for gene expression analysis. To examine the effects on ER positive cells, we treated MCF7 cells with digitoxin at 1 ?g/ml and collected RNA for RT-PCR analysis. In addition, we assayed the growth inhibitory effect of low doses of digitoxin combined with paclitaxel and determined combination index values. Results: To reveal primary effects, we examined digitoxin’s effect 6 h post-treatment with the highest dose, 1?g/ml, and found upregulation of the stress response genes EGR-1 and NAB2, lipid biosynthetic genes and the tumor suppressor gene p21, and downregulation of the mitotic cell cycle gene CDC16 and the replication gene PolR3B. RT-PCR analysis validated effects on stress response, apoptotic and cell cycle genes on MDA-MB-453 and MCF7 cells. Western blot analysis confirmed induction of EGR1 protein at 1 h and ATF3 at 24 h. Paclitaxel, as well as digitoxin, inhibited the in vitro activity of the purified Na+-K+-ATPase; digitoxin enhanced the growth inhibitory effects of paclitaxel on Her2 overexpressing breast cancer cells. Conclusions: Our studies show the potential of digitoxin to prevent and treat breast cancer and indicate that the combination of digitoxin and paclitaxel is a promising treatment for ER negative breast cancer. These findings are the first to alert physicians to the possible dangers to patients who take a combination of digitoxin and paclitaxel. The potential dangers ensuing when paclitaxel and digitoxin are combined are dependent on the dose of digitoxin. PMID:21139994

Einbond, Linda Saxe; Wu, Hsan-au; Su, Tao; Chang, Tangel; Panjikaran, Maya; Wang, Xiaomei; Goldsberry, Sarah

2010-01-01

301

Transport and cytotoxicity of paclitaxel, docetaxel, and novel taxanes in human breast cancer cells.  

PubMed

The resistance of tumors to classic taxanes (paclitaxel and docetaxel) presents problems in chemotherapy. Thus, new taxanes with higher antitumor activity in resistant tumors are synthesized. This study compared cytotoxicity and transport of paclitaxel and docetaxel with novel taxanes SB-T-1103, SB-T-1214, and SB-T-1216 in adriamycin-sensitive (MDA-MB-435) and -resistant (NCI/ADR-RES) human breast cancer cells. The cell lines examined differ in adriamycin transport, suggesting different expression of ABC membrane transporters. Reverse transcription-polymerase chain reaction revealed that NCI/ADR-RES cells expressed high levels of P-glycoprotein mRNA, which was absent in MDA-MB-435 cells, while the opposite was true for MRP2 mRNA. Both cell lines shared or differently expressed eight other ABC transporters and LRP. NCI/ADR-RES cells were 1,000-fold more resistant to paclitaxel and 600-fold more resistant to docetaxel in MTT assay than MDA-MB-435 cells, but almost equally sensitive to SB-T-1103, SB-T-1214, and SB-T-1216. This complied with the fact that NCI/ADR-RES cells absorbed almost 20-fold less [14C]paclitaxel, about 7-fold less docetaxel, and almost equal amounts of SB-T-1103, SB-T-1214, and SB-T-1216 as the MDA-MB-435 cells. Verapamil increased uptake of [14C]paclitaxel by NCI/ADR-RES cells 7-fold and decreased its efflux 2.5-fold; in contrast, it weakly influenced uptake and increased the efflux in MDA-MB-435 cells. SB-T-1103 and SB-T-1216 did not influence transport of paclitaxel, but SB-T-1214 decreased [14C]paclitaxel uptake in both cell lines indicating inhibition of uptake. This suggests that the novel taxanes are not inhibitors of P-glycoprotein. However, novel taxanes exert much higher activity on resistant tumor cells than classic taxanes and seem to be potential drugs for therapy in taxane-resistant tumors. PMID:16059735

Ehrlichova, Marie; Vaclavikova, Radka; Ojima, Iwao; Pepe, Antonella; Kuznetsova, Larisa V; Chen, Jin; Truksa, Jaroslav; Kovar, Jan; Gut, Ivan

2005-07-01

302

Genetic inactivation and pharmacological blockade of sigma-1 receptors prevent paclitaxel-induced sensory-nerve mitochondrial abnormalities and neuropathic pain in mice  

PubMed Central

Background Paclitaxel, a widely-used antineoplastic drug, produces a painful peripheral neuropathy that in rodents is associated with peripheral-nerve mitochondrial alterations. The sigma-1 receptor (?1R) is a ligand-regulated molecular chaperone involved in mitochondrial calcium homeostasis and pain hypersensitivity. This receptor plays a key role in paclitaxel-induced neuropathic pain, but it is not known whether it also modulates mitochondrial abnormalities. In this study, we used a mouse model of paclitaxel-induced neuropathic pain to test the involvement of the ?1R in the mitochondrial abnormalities associated with paclitaxel, by using genetic (?1R knockout mice) and pharmacological (?1R antagonist) approaches. Results Paclitaxel administration to wild-type (WT) mice produced cold- and mechanical-allodynia, and an increase in the frequency of swollen and vacuolated mitochondria in myelinated A-fibers, but not in C-fibers, of the saphenous nerve. Behavioral and mitochondrial alterations were marked at 10 days after paclitaxel-administration and had resolved at day 28. In contrast, paclitaxel treatment did not induce allodynia or mitochondrial abnormalities in ?1R knockout mice. Moreover, the prophylactic treatment of WT mice with BD-1063 also prevented the neuropathic pain and mitochondrial abnormalities induced by paclitaxel. Conclusions These results suggest that activation of the ?1R is necessary for development of the sensory nerve mitochondrial damage and neuropathic pain produced by paclitaxel. Therefore, ?1R antagonists might have therapeutic value for the prevention of paclitaxel-induced neuropathy. PMID:24517272

2014-01-01

303

Raman confocal microscopy and AFM combined studies of cancerous cells treated with Paclitaxel  

NASA Astrophysics Data System (ADS)

Paclitaxel interferes with the normal function of microtubule breakdown, induces apoptosis in cancer cells and sequesters free tubulin. As this drug acts also on other cell mechanisms it is important to monitor its accumulation in the cell compartments. The intracellular spreading of the drug was followed using a WITEC 300R confocal Raman microscope equipped with a CCD camera. Hence Atomic force microscopy (an MFP3D- Asylum Research AFM) in imaging and force mode was used to determine the morphological and mechanical modifications induced on living cells. These studies were performed on living epithelial MCF-7 breast cancer cells. Paclitaxel was added to cell culture media for 3, 6 and 9 hours. Among the specific paclitaxel Raman bands we selected the one at 1670 cm-1 because it is not superposed by the spectrum of the cells. Confocal Raman images are formed by monitoring this band, the NH2 and the PO4 band. Paclitaxel slightly accumulates in the nucleus forming patches. The drug is also concentrated in the vicinity of the cell membrane and in an area close to the nucleus where proteins accumulate. Our AFM images reveal that the treated cancerous MCF-7 cells keep the same size as the non treated ones, but their shape becomes more oval. Cell's elasticity is also modified: a difference of 2 kPa in the Young Modulus characterizes the treated MCF-7 mammary cancerous cell. Our observations demonstrate that paclitaxel acts not only on microtubules but accumulates also in other cell compartments (nucleus) where microtubules are absent.

Derely, L.; Collart Dutilleul, P.-Y.; Michotte de Welle, Sylvain; Szabo, V.; Gergely, C.; Cuisinier, F. J. G.

2011-03-01

304

Design, Synthesis and Biological Assessment of a Triazine Dendrimer with Approximately 16 Paclitaxel Groups and 8 PEG Groups  

E-print Network

to a dichlorotriazine with aminomethylpiperidine. The resulting dichlorotriazine bearing two paclitaxel groups could. The hydrodynamic radius of the target was found to be 15.8 nm by dynamic light scattering, an observation

Annunziata, Onofrio

305

Dosimetric predictors of radiation esophagitis in patients treated for non-small-cell lung cancer with carboplatin\\/paclitaxel\\/radiotherapy  

Microsoft Academic Search

Purpose: To establish dosimetric predictors of radiation esophagitis (RE) in patients treated with a combination of carboplatin, paclitaxel, and radiotherapy.Methods and Materials: Three-dimensional radiotherapy plans of 26 patients with non-small-cell lung cancer who received 50–60 Gy of radiotherapy concurrently with weekly administration of carboplatin (AUC 2) and paclitaxel (40–45 mg\\/m2) were reviewed in conjunction with RE. The factors analyzed included

Saeko Hirota; Kayoko Tsujino; Masahiro Endo; Yoshikazu Kotani; Miyako Satouchi; Tetsuji Kado; Yoshio Hishikawa; Kayoko Obayashi; Yoshiki Takada; Michio Kono; Mitsuyuki Abe

2001-01-01

306

Randomized Trial of Paclitaxel Plus Supportive Care Versus Supportive Care for Patients With Advanced Non-Small-Cell Lung Cancer  

Microsoft Academic Search

Background: In phase II trials, paclitaxel has been shown to have antitumor activity in patients with advanced non-small- cell lung cancer (NSCLC). However, the survival and qual- ity-of-life (QOL) benefits of paclitaxel used as a single agent compared with supportive care alone have not been assessed in a randomized clinical trial. Methods: A total of 157 pa- tients with stage

Malcolm Ranson; Neville Davidson; Marianne Nicolson; Stephen Falk; Jim Carmichael; Pedro Lopez; Heather Anderson; Nancy Gustafson; Allison Jeynes; Giles Gallant; Terri Washington; Nick Thatcher

2000-01-01

307

Oxycodone Induces Overexpression of P-Glycoprotein (ABCB1) and Affects Paclitaxel's Tissue Distribution in Sprague Dawley Rats  

PubMed Central

Previous studies suggest that P-glycoprotein (P-gp) modulates the PK/PD of many compounds including opioid agonists and chemotherapeutic agents. The objective of this study was to assess the P-gp affinity status of oxycodone, the P-gp expression, and the paclitaxel’s tissue distribution in oxycodone-treated rats. P-gp ATPase assay, Caco-2 transepithelial permeability studies, and mdr1a/b (?/?) mice were used to assess the P-gp affinity status of oxycodone. P-gp expression was determined by Western blot analysis while [14C] paclitaxel’s distributions in the liver, kidney, brain, and plasma tissues were determined by liquid scintillation counter. Oxycodone stimulated the P-gp ATPase activity in a concentration-dependant manner. The Caco-2 secretory transport of oxycodone was reduced from 3.64 ×10?5 to 1.96 × 10?5 cm/s (p <0.05) upon preincubation with the P-gp inhibitor, verapamil. The brain levels of oxycodone in mdr1a/b (+/+) were not detectable (<15 ng/mL) while in mdr1a/b (?/?) the average levels were 115 ± 39 ng/mL. The P-gp protein levels were increased by 1.3–4.0 folds while paclitaxel’s tissue distributions were decreased by 38–90% (p <0.05) in oxycodone-treated rats. These findings display that oxycodone is a P-gp substrate, induces overexpression of P-gp, and affects paclitaxel’s tissue distribution in a manner that may influence its chemotherapeutic activity. PMID:17593551

HASSAN, HAZEM E.; MYERS, ALAN L.; LEE, INSONG J.; COOP, ANDREW; EDDINGTON, NATALIE D.

2012-01-01

308

Paclitaxel-incorporated nanoparticles using block copolymers composed of poly(ethylene glycol)/poly(3-hydroxyoctanoate).  

PubMed

Block copolymers composed of poly(3-hydroxyoctanoate) (PHO) and methoxy poly(ethylene glycol) (PEG) were synthesized to prepare paclitaxel-incorporated nanoparticle for antitumor drug delivery. In a (1)H-NMR study, chemical structures of PHO/PEG block copolymers were confirmed and their molecular weight (M.W.) was analyzed with gel permeation chromatography (GPC). Paclitaxel as a model anticancer drug was incorporated into the nanoparticles of PHO/PEG block copolymer. They have spherical shapes and their particle sizes were less than 100 nm. In a (1)H-NMR study in D2O, specific peaks of PEG solely appeared while peaks of PHO disappeared, indicating that nanoparticles have core-shell structures. The higher M.W. of PEG decreased loading efficiency and particle size. The higher drug feeding increased drug contents and average size of nanoparticles. In the drug release study, the higher M.W. of PEG block induced the acceleration of drug release rate. The increase in drug contents induced the slow release rate of drug. In an antitumor activity study in vitro, paclitaxel nanoparticles have practically similar anti-proliferation activity against HCT116 human colon carcinoma cells. In an in vivo animal study using HCT116 colon carcinoma cell-bearing mice, paclitaxel nanoparticles have enhanced antitumor activity compared to paclitaxel itself. Therefore, paclitaxel-incorporated nanoparticles of PHO/PEG block copolymer are a promising vehicle for antitumor drug delivery. PMID:25288916

Kim, Hyun Yul; Ryu, Je Ho; Chu, Chong Woo; Son, Gyung Mo; Jeong, Young-Il; Kwak, Tae-Won; Kim, Do Hyung; Chung, Chung-Wook; Rhee, Young Ha; Kang, Dae Hwan; Kim, Hyung Wook

2014-01-01

309

Paclitaxel-incorporated nanoparticles using block copolymers composed of poly(ethylene glycol)/poly(3-hydroxyoctanoate)  

PubMed Central

Block copolymers composed of poly(3-hydroxyoctanoate) (PHO) and methoxy poly(ethylene glycol) (PEG) were synthesized to prepare paclitaxel-incorporated nanoparticle for antitumor drug delivery. In a 1H-NMR study, chemical structures of PHO/PEG block copolymers were confirmed and their molecular weight (M.W.) was analyzed with gel permeation chromatography (GPC). Paclitaxel as a model anticancer drug was incorporated into the nanoparticles of PHO/PEG block copolymer. They have spherical shapes and their particle sizes were less than 100 nm. In a 1H-NMR study in D2O, specific peaks of PEG solely appeared while peaks of PHO disappeared, indicating that nanoparticles have core-shell structures. The higher M.W. of PEG decreased loading efficiency and particle size. The higher drug feeding increased drug contents and average size of nanoparticles. In the drug release study, the higher M.W. of PEG block induced the acceleration of drug release rate. The increase in drug contents induced the slow release rate of drug. In an antitumor activity study in vitro, paclitaxel nanoparticles have practically similar anti-proliferation activity against HCT116 human colon carcinoma cells. In an in vivo animal study using HCT116 colon carcinoma cell-bearing mice, paclitaxel nanoparticles have enhanced antitumor activity compared to paclitaxel itself. Therefore, paclitaxel-incorporated nanoparticles of PHO/PEG block copolymer are a promising vehicle for antitumor drug delivery. PMID:25288916

2014-01-01

310

Preparation and characterization of poly(lactic acid)–poly(ethylene glycol)–poly(lactic acid) (PLA–PEG–PLA) microspheres for controlled release of paclitaxel  

Microsoft Academic Search

Microspheres of a new kind of copolymer, poly(lactic acid)–poly(ethylene glycol)–poly(lactic acid) (PLA–PEG–PLA), are proposed in the present work for clinical administration of an antineoplastic drug paclitaxel with hypothesis that incorporation of a hydrophilic PEG segment within the hydrophobic PLA might facilitate the paclitaxel release. Paclitaxel-loaded PLA–PEG–PLA microspheres of various compositions were prepared by the solvent extraction\\/evaporation method. Characterization of the

Gang Ruan; Si-Shen Feng

2003-01-01

311

Discovery of differentially expressed genes associated with paclitaxel resistance using cDNA array technology: analysis of interleukin (IL) 6, IL-8, and monocyte chemotactic protein 1 in the paclitaxel-resistant phenotype.  

PubMed

In an attempt to define the molecular changes associated with the paclitaxel-resistant phenotype in human cancer, a paclitaxel-resistant ovarian cancer cell line, SKOV-3TR, was established through stepwise selection in increasing paclitaxel concentrations. SKOV-3TR was cross- resistant to doxorubicin and vincristine and overexpressed multidrug resistance gene 1 but not multidrug resistance associated protein. SKOV-3TR and the paclitaxel-sensitive SKOV-3 parent line were characterized using human cDNA array technology that examined expression of a wide variety of genes involved in cell growth, signal transduction, cell death, and immune function. cDNA probes from reverse transcribed mRNAs of both paclitaxel-resistant and parent cells were compared to identify genes differentially expressed in the paclitaxel-resistant cells. Of 588 different human cDNA transcripts compared, 6 genes were found to be markedly decreased, and 12 genes increased in the resistant subline. Northern analysis and/or reverse transcription-PCR confirmed that 12 of these 18 genes were over- or underexpressed in SKOV-3TR. In addition, at least eight of the genes were found differentially expressed in several other paclitaxel- and/or doxorubicin-resistant cell lines, both those with increased multidrug resistance expression and those without. Included in the set of overexpressed genes were the cytokines/chemokines interleukin 6, interleukin 8, and monocyte chemotactic protein 1. ELISA assays confirm that mRNA overexpression of these cytokine/chemokines was associated with the increased secretion of these molecules in the tissue culture supernatant. Evaluation of supernatants from an expanded collection of paclitaxel- and Adriamycin-resistant cell lines demonstrated that all of the resistant lines had significant overexpression of at least one cytokine/chemokine as compared with their drug-sensitive parent line. The overexpression of these cytokines seemed to be stable and associated with a drug-resistant phenotype with only a modest induction of cytokine expression in the parent line with short-term paclitaxel exposure. These findings suggest that the development of paclitaxel resistance is accompanied by multiple changes in gene expression including stable alterations in selective chemokine and cytokine expression. The role these associated genetic changes have in the drug-resistant phenotype is discussed. PMID:10589757

Duan, Z; Feller, A J; Penson, R T; Chabner, B A; Seiden, M V

1999-11-01

312

Silencing of astrin induces the p53-dependent apoptosis by suppression of HPV18 E6 expression and sensitizes cells to paclitaxel treatment in HeLa cells.  

PubMed

Astrin is a microtubule-associated protein and localizes with mitotic spindles in the M-phase. We silenced the expression of astrin protein and tested the cell viability in response to paclitaxel treatment in paclitaxel-sensitive and paclitaxel-resistant cells. We found that the absence of astrin by siRNA resulted in the activation of a p53-dependent apoptosis, which elevated pro-apoptotic Bax expression and increased the activity of caspase-3 in astrin-depleted cells. The HPV18 E6 transcription was found to be inhibited along with the increase expression of p53. Intriguingly, the expression of astrin decreased in paclitaxel-sensitive HeLa cells but remained steady in paclitaxel-resistant cells in response to paclitaxel treatment. Furthermore, we identified that the depletion of astrin caused more cell death both in paclitaxel-sensitive and -resistant cells in combination with paclitaxel treatment. These findings suggest that the silencing of astrin induce a p53-dependent apoptosis and has an additive effect on paclitaxel treatment. PMID:16546135

Yang, Yuh-Cheng; Hsu, Yun-Ting; Wu, Chao-Chih; Chen, Hsiang-Ting; Chang, Mau-Sun

2006-05-01

313

Nanoparticle albumin-bound paclitaxel in a patient with locally advanced breast cancer and taxane-induced skin toxicity: a case report  

PubMed Central

Introduction Taxanes have demonstrated effectiveness in the treatment of breast cancer, the most common type of cancer in women. The toxicity profile of taxanes (including skin toxicities) induces dose adjustment, delay, or discontinuation, which prevents a sufficient dose intensity to achieve a response. Nanoparticle albumin-bound paclitaxel, a solvent-free form of paclitaxel, prevents toxicities and reduces the pharmacokinetic interferences between paclitaxel and other drugs. Case presentation We describe the case of a 55-year-old Caucasian woman with locally advanced breast cancer treated with neoadjuvant therapy who developed secondary skin toxicity due to delayed hypersensitivity to taxanes. She received Adriamycin® (doxorubicin), cyclophosphamide and docetaxel and developed toxicity that promoted treatment delay and a switch to weekly paclitaxel. After the third and fourth weeks of treatment, paclitaxel toxicities also induced treatment delay and paclitaxel was switched to nanoparticle albumin-bound paclitaxel. She completed the five planned nanoparticle albumin-bound paclitaxel cycles with acceptable tolerability (including persistent grade 2 neuropathy) and without dose delay or adjustments. Clinical response was achieved although pathological response was not good. Conclusions Nanoparticle albumin-bound paclitaxel treatment is a good option for patients with breast cancer with taxanes-related skin toxicity. This drug allows the treatment to be completed with acceptable tolerance in our case. PMID:24386978

2014-01-01

314

Fabrication of Micro and Nanoparticles of Paclitaxel-loaded Poly L Lactide for Controlled Release using Supercritical Antisolvent Method: Effects of Thermodynamics and Hydrodynamics  

E-print Network

This paper presents the fabrication of controlled release devices for anticancer drug paclitaxel using supercritical antisolvent method. The thermodynamic and hydrodynamic effects during supercritical antisolvent process ...

Lee, Lai Yeng

315

Electrocoating of stainless steel coronary stents for extended release of paclitaxel.  

PubMed

Nonbiodegradable polymer coating based on N-(2-carboxyethyl)pyrrole (PPA) and butyl ester of PPA (BuOPy) were successfully electrodeposited on a stainless steel stent surface using cyclic voltammetry. Chemical composition of the coating was examined by X-ray photoelectron spectroscopy. Polymer stability was examined by immersing the coated stent into 1:1 solution of fetal calf serum:seline solution up to 1 year and implantation subcutaneously in mouse for 1 week. Morphology changes were then recorded by scanning electron microscopy. Paclitaxel loading was carried out by immersion into drug solution and its release was detected by HPLC. The results show that thin (single micrometers), uniform coating with various morphology and hydrophobicity can be created by electrochemical deposition. The polymer did not show significant histopathological or morphological changes in vitro and in vivo. The surface properties allow loading appropriate amounts of paclitaxel and release it slowly up to a month. PMID:18306316

Okner, R; Oron, M; Tal, N; Nyska, A; Kumar, N; Mandler, D; Domb, A J

2009-02-01

316

Screening of the needles of different yew species and cultivars for paclitaxel and related taxoids.  

PubMed

The needles of several yew species and cultivars were analysed by high-pressure liquid chromatography for paclitaxel, 10-deacetylpaclitaxel, cephalomannine, baccatin III, 10-deacetylbaccatin III and brevifoliol. About 750 samples were collected from five different locations in the Netherlands and the UK. The results of this screening show a large variation in taxane content between the different species and cultivars. The content of paclitaxel and 10-deacetylbaccatin III varied from 0 to 500 micrograms/g and 0 to 4800 micrograms/g dried needles, respectively. Brevifoliol was found in a very high concentration in Taxus brevifolia. 10-Deacetylpaclitaxel, cephalomannine and baccatin III were found in concentrations ranging from 0 to 500 micrograms/g dried needles. PMID:10703062

van Rozendaal, E L; Lelyveld, G P; van Beek, T A

2000-02-01

317

Detection of apoptosis caused by anticancer drug paclitaxel in MCF-7 cells by confocal Raman microscopy  

NASA Astrophysics Data System (ADS)

Confocal Raman Microscopy, a non-invasive, label free imaging technique is used to study apoptosis in living MCF-7 cells. The images are based on Raman spectra of cells components. K-mean clustering was used to determine mitochondria position in cells and cytochrome c distribution inside the cells was based on correlation analysis. Cell apoptosis is defined as cytochrome c diffusion in cytoplasm. Co-localization of cytochrome c is found within mitochondria after three hours of incubation with 10 ?M paclitaxel. Our results demonstrate that the presence of paclitaxel at this concentration in the culture media for 3 hours does not induce apoptosis of MCF7 cells via a caspase independent pathway.

Salehi, H.; Middendorp, E.; Végh, A.-G.; Ramakrishnan, S.-K.; Gergely, C.; Cuisinier, F. J. G.

2013-02-01

318

Confocal Raman data analysis enables identifying apoptosis of MCF-7 cells caused by anticancer drug paclitaxel  

NASA Astrophysics Data System (ADS)

Confocal Raman microscopy is a noninvasive, label-free imaging technique used to study apoptosis of live MCF-7 cells. The images are based on Raman spectra of cells components, and their apoptosis is monitored through diffusion of cytochrome c in cytoplasm. K-mean clustering is used to identify mitochondria in cells, and correlation analysis provides the cytochrome c distribution inside the cells. Our results demonstrate that incubation of cells for 3 h with 10 ?M of paclitaxel does not induce apoptosis in MCF-7 cells. On the contrary, incubation for 30 min at a higher concentration (100 ?M) of paclitaxel induces gradual release of the cytochrome c into the cytoplasm, indicating cell apoptosis via a caspase independent pathway.

Salehi, Hamideh; Middendorp, Elodie; Panayotov, Ivan; Dutilleul, Pierre-Yves Collard; Vegh, Attila-Gergely; Ramakrishnan, Sathish; Gergely, Csilla; Cuisinier, Frederic

2013-05-01

319

Development and evaluation of paclitaxel loaded PLGA:poloxamer blend nanoparticles for cancer chemotherapy.  

PubMed

This investigation described the development of novel PLGA:poloxamer blend nanoparticles for intravenous administration of paclitaxel in order to limit the cremophor-associated adverse effects. The developed formulation was well-characterized using various techniques including scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy and differential scanning calorimetry. The nanoparticles had an average particle size around 180nm and zeta potential of -22.7mV. The in vitro release study of nanoparticles exhibited biphasic release pattern. The non-hemolytic potential of the nanoparticles indicated the suitability of the developed formulation for intravenous administration. The PLGA:poloxamer blend nanoparticles showed significantly improved cytotoxicity in cell lines (MCF-7 and Colo-205), as compared to free drug. Further, the developed formulation was stable under the accelerated storage conditions. In conclusion, the results indicated that the developed polymeric formulation is a novel and potential alternative for the paclitaxel delivery. PMID:24942992

Gupta, Prem N; Jain, Sharad; Nehate, Chetan; Alam, Noor; Khare, Vaibhav; Dubey, Ravindra Dhar; Saneja, Ankit; Kour, Smit; Singh, Shashank K

2014-08-01

320

Royal jelly protects from taxol-induced testicular damages via improvement of antioxidant status and up-regulation of E2f1.  

PubMed

This study was carried out to evaluate the protective effects of royal jelly (RJ) on taxol (TXL)-induced damage of the testis. Wistar rats were divided into control and test groups. The test group was divided into five subgroups; the first four groups along with TXL administration (7.5?mg/kg body weight (bw), weekly), received various doses of RJ (0, 50, 100, and 150?mg/kg bw). The last group received only RJ at 100?mg/kg. Royal jelly lowered the TXL-induced malondialdehyde and nitric oxide levels and enhanced the total thiol molecules in the testis. Remarkably RJ reduced the TXL-induced pathological injuries such as cellular shrinkage and seminiferous tubule depletion. Taxol-reduced sperm viability (27.5?±?2.98 % vs. 85.0?±?8.6% in the control group) was recovered by RJ administration as 80.5?±?10.6% of the sperm were found alive in the group of animals which received 150?mg/kg RJ. The TXL-exposed and TXL plus RJ-administered animals showed a significant up-regulation of transcription factor E2f1 mRNA. Our data suggest that the TXL-induced histopathological and biochemical alterations could be protected by the administration of RJ. The RJ protective effects might be attributed to its antioxidant capacity and its capability in the regulation of E2f1 expression. PMID:24377747

Delkhoshe-Kasmaie, Fatemeh; Malekinejad, Hassan; Khoramjouy, Mona; Rezaei-Golmisheh, Ali; Janbaze-Acyabar, Hamed

2014-04-01

321

Purification and characterization of taxa-4(5),11(12)-diene synthase from Pacific yew (Taxus brevifolia) that catalyzes the first committed step of taxol biosynthesis.  

PubMed

The first step in the biosynthesis of taxol in Pacific yew (Taxus brevifolia) is the cyclization of the universal diterpene precursor geranylgeranyl pyrophosphate to taxa-4(5),11(12)-diene. This parent olefin of the taxane diterpenoids is then elaborated to taxol and related compounds by a complex series of reactions involving oxidations and side-chain acylations. Cyclization activity is located principally in yew stem bark and adhering cambium. The operationally soluble cyclization enzyme was partially purified (approximately 600-fold) by combination of anion exchange, hydrophobic interaction, and dye-ligand chromatography. Nondenaturing, followed by denaturing, polyacrylamide gel electrophoresis, in combination with gel permeation chromatography, allowed the identification of taxadiene synthase as a monomeric protein of molecular weight 79,000. In general properties (divalent metal ion requirement, kinetic constants, molecular weight), the taxadiene synthase of Pacific yew is similar to the diterpene cyclase abietadiene synthase involved in resin acid biosynthesis in other gymnosperms. However, in pH optimum and response to inhibitors, these two diterpene cyclases are distinctly different. The activity (and enzyme protein) levels of Pacific yew taxadiene synthase are much lower than those for abietadiene synthase of lodgepole pine stem (constitutive) or of grand fir stem (wound-inducible) and the enzyme is not inducible to higher levels by stem wounding or elicitor treatment. PMID:7574719

Hezari, M; Lewis, N G; Croteau, R

1995-10-01

322

Mesothelin inhibits paclitaxel-induced apoptosis through the PI3K pathway.  

PubMed

Mesothelin, a secreted protein, is overexpressed in some cancers, but its exact function remains unclear. The aim of the present study was to evaluate the possible function of mesothelin. Real-time PCR, RT (reverse transcription)-PCR, cytotoxicity assays, proliferative assays, apoptotic assays by Hoechst staining, detection of active caspases 3 and 7 by flow cytometric analysis, and immunoprecipitation and immunoblotting were performed. Cancer tissues in paclitaxel-resistant ovarian cancer patients expressed higher levels of mesothelin as assessed using real-time PCR than paclitaxel-sensitive ovarian cancer patients (the mean crossing point value change of mesothelin was 26.9+/-0.4 in the resistant group and 34.3+/-0.7 for the sensitive group; P<0.001). Mesothelin also protected cells from paclitaxel-induced apoptosis. The protein expression of Bcl-2 family members, such as Bcl-2 and Mcl-1, was significantly increased regardless of whether cells were treated with exogenous mesothelin or were mesothelin-transfectants. Furthermore, mesothelin-treated cells revealed rapid tyrosine phosphorylation of the p85 subunit of PI3K (phosphoinositide 3-kinase) and ERK (extracellular-signal-regulated kinase) 1/2 for enhancing MAPK (mitogen-activated protein kinase) activity. The anti-apoptotic ability was suppressed and the expression of Bcl-2 family in response to mesothelin was altered by inhibiting PI3K activity, but not by inhibiting MAPK activity. Thus mesothelin can inhibit paclitaxel-induced cell death mainly by involving PI3K signalling in the regulation of Bcl-2 family expression. Mesothelin is a potential target in reducing resistance to cytotoxic drugs. PMID:19747165

Chang, Ming-Cheng; Chen, Chi-An; Hsieh, Chang-Yao; Lee, Chien-Nan; Su, Yi-Ning; Hu, Yu-Hao; Cheng, Wen-Fang

2009-12-15

323

Optimization of productivity in solvent gradient simulated moving bed for paclitaxel purification  

Microsoft Academic Search

The isocratic and solvent gradient SMBs for paclitaxel purification were optimized to maximize productivity under constraints of product purities and zone flow rate. The solvent composition in the feed and in the desorbent, zone flow rates, and switching time were optimized using non-dominated sorting genetic algorithm with elitism and jumping genes (NSGA-II-JG) and rate model simulations. The highest productivity is

Sungyong Mun; Nien-Hwa Linda Wang

2008-01-01

324

Methylseleninic Acid Enhances Paclitaxel Efficacy for the Treatment of Triple-Negative Breast Cancer  

Microsoft Academic Search

A major challenge in breast cancer therapy is the lack of an effective therapeutic option for a particularly aggressive subtype of breast cancer, triple-negative breast cancer. Here we provide the first preclinical evidence that a second-generation selenium compound, methylseleninic acid, significantly enhances the anticancer efficacy of paclitaxel in triple-negative breast cancer. Through combination-index value calculation, we demonstrated that methylseleninic acid

Yanfeng Qi; Xueqi Fu; Zhenggang Xiong; Haitao Zhang; Steven M. Hill; Brian G. Rowan; Yan Dong

2012-01-01

325

Intracellular clusterin negatively regulates ovarian chemoresistance: compromised expression sensitizes ovarian cancer cells to paclitaxel  

Microsoft Academic Search

Understanding the molecular events that lead to paclitaxel (TX) resistance is necessary to identify effective means to prevent\\u000a chemoresistance. Previously, results from our lab revealed that secretory clusterin (CLU) form positively mediates TX response\\u000a in ovarian cancer cells. Thus, we had interest to study the role of another non-secreted form (intracellular clusterin (i-CLU))\\u000a in chemo-response. Here, we provide evidences that

Mohamed Kamel Hassan; Hidemichi Watari; Saverio Bettuzzi; Noriaki Sakuragi

326

Prodigiosin down-regulates survivin to facilitate paclitaxel sensitization in human breast carcinoma cell lines  

SciTech Connect

Prodigiosin is a bacterial metabolite with potent anticancer activity, which is attributed to its proapoptotic effect selectively active in malignant cells. Still, the molecular mechanisms whereby prodigiosin induces apoptosis remain largely unknown. In particular, the role of survivin, a vital inhibitor of apoptosis, in prodigiosin-induced apoptosis has never been addressed before and hence was the primary goal of this study. Our results showed that prodigiosin dose-dependently induced down-regulation of survivin in multiple breast carcinoma cell lines, including MCF-7, T-47D and MDA-MB-231. This down-regulation is mainly regulated at the level of transcription, as prodigiosin reduced the levels of both survivin mRNA and survivin promoter activity but failed to rescue survivin expression when proteasome-mediated degradation is abolished. Importantly, overexpression of survivin rendered cells more resistant to prodigiosin, indicating an essential role of survivin down-regulation in prodigiosin-induced apoptosis. In addition, we found that prodigiosin synergistically enhanced cell death induced by paclitaxel, a chemotherapy drug known to up-regulate survivin that in turn confers its own resistance. This paclitaxel sensitization effect of prodigiosin is ascribed to the lowering of survivin expression, because prodigiosin was shown to counteract survivin induction by paclitaxel and, notably, the sensitization effect was severely abrogated in cells that overexpress survivin. Taken together, our results argue that down-regulation of survivin is an integral component mediating prodigiosin-induced apoptosis in human breast cancer cells, and further suggest the potential of prodigiosin to sensitize anticancer drugs, including paclitaxel, in the treatment of breast cancer.

Ho, T.-F. [Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Department of Medical Technology, Central Taiwan University of Science and Technology, Taichung, Taiwan (China); Peng, Y.-T.; Chuang, S.-M.; Lin, S.-C.; Feng, B.-L. [Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Lu, C.-H. [Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Department of Obstetrics and Gynecology, Taichung Veterans General Hospital, Taichung, Taiwan (China); Yu, W.-J. [Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan (China); Chang, J.-S. [Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan (China); Sustainable Environment Research Center, National Cheng Kung University, Tainan, Taiwan (China)], E-mail: changjs@mail.ncku.edu.tw; Chang, C.-C. [Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China)], E-mail: chia_che@dragon.nchu.edu.tw

2009-03-01

327

Endostatin gene therapy enhances the efficacy of paclitaxel to suppress breast cancers and metastases in mice  

Microsoft Academic Search

Chemotherapy combined with antiangiogenic therapy is more effective than chemotherapy alone. The aim of this study was to\\u000a investigate whether endostatin, a potent anti-angiogenic agent, could enhance the efficacy of paclitaxel to combat breast\\u000a cancer. An expression plasmid encoding mouse endostatin (End-pcDNA3.1) was constructed, which produced intense expression\\u000a of endostatin and inhibited angiogenesis in the chorioallantoic membrane assay. 4T1 breast

Jie Li; Xuesong Dong; Zongzhen Xu; Xian Jiang; Hongchi Jiang; Geoffrey W Krissansen; Xueying Sun

2008-01-01

328

Long Circulating Lectin Conjugated Paclitaxel Loaded Magnetic Nanoparticles: A New Theranostic Avenue for Leukemia Therapy  

Microsoft Academic Search

Amongst all leukemias, Bcr-Abl positive chronic myelogenous leukemia (CML) confers resistance to native drug due to multi drug resistance and also resistance to p53 and fas ligand pathways. In the present study, we have investigated the efficacy of microtubule stabilizing paclitaxel loaded magnetic nanoparticles (pac-MNPs) to ascertain its cytotoxic effect on Bcr-Abl positive K562 cells. For active targeted therapy, pac-MNPs

Abhalaxmi Singh; Fahima Dilnawaz; Sanjeeb Kumar Sahoo

2011-01-01

329

Syngeneic Mouse Model of Epithelial Ovarian Cancer: Effects of Nanoparticulate Paclitaxel, Nanotax®  

Microsoft Academic Search

In 2006, it has been estimated that 20,180 women in the United States will be diagnosed with ovarian cancer, and 15,310 women\\u000a will die from the disease (1). Although advances have occurred in treatment strategies, success remains limited (1). The median\\u000a overall survival for patients with advanced ovarian cancer and receiving the current standards of treatment (surgery and paclitaxel\\/platinum\\u000a chemotherapy)

Katherine F. Roby; Fenghui Niu; Roger A. Rajewski; Charles Decedue; Bala Subramaniam; Paul F. Terranova

330

PACLITAXEL SENSITIVITY CORRELATES WITH P53 STATUS AND DNA FRAGMENTATION, BUT NOT G2\\/M ACCUMULATION  

Microsoft Academic Search

Purpose: The antitumor agent paclitaxel (Taxolt) has been shown to arrest cells in mitosis through microtubule stabilization and to induce apoptosis. The tumor suppressor gene p53 is implicated in the regulation of cell cycle checkpoints and can mediate apoptotic cell death. Although initial studies demonstrated that various DNA-damaging agents can induce p53, more recent studies have also shown p53 induction

EILEEN RAKOVITCH; WILFREDO MELLADO; ERIC J. HALL; D. PHIL; TEJ K. PANDITA; SATIN SAWANT; CHARLES R. GEARD

1999-01-01

331

Influence of drug formulation on OATP1B-mediated transport of paclitaxel.  

PubMed

Taxane antineoplastic agents are extensively taken up into hepatocytes by OATP1B-type transporters before metabolism and excretion. Because the biodistributional properties imposed upon these agents by different solubilizers drive clinically important pharmacodynamic endpoints, we tested the hypothesis that the in vitro and in vivo interaction of taxanes with OATP1B transporters is affected by the choice of drug delivery system. Transport of paclitaxel, docetaxel, and cabazitaxel was studied in vitro using various cell lines transfected with OATP1B1, OATP1B3, or the rodent equivalent OATP1B2. Pharmacokinetic studies were done in wild-type and OATP1B2-knockout mice in the presence or absence of polysorbate 80 (PS80) or Kolliphor EL (formerly Cremophor EL; CrEL). Paclitaxel and docetaxel, but not cabazitaxel, were transported substrates of OATP1B1, OATP1B3, and OATP1B2, and these in vitro transport processes were strongly reduced in the presence of clinically relevant concentrations of PS80 and CrEL. When paclitaxel was administered without any solubilizers, deficiency of OATP1B2 in mice was associated with a significantly decreased systemic clearance because of a liver distribution defect (P=0.000484). However, this genotype dependence of paclitaxel clearance was masked in the presence of PS80 or CrEL because of significant inhibition of OATP1B2-mediated hepatocellular uptake of the drug (P<0.05). Our findings confirm the importance of OATP1B-type transporters in the hepatic elimination of taxanes and indicate that this process can be inhibited by PS80 and CrEL. These results suggest that the likelihood of drug-drug interactions mediated by these transporters is strongly dependent on the selected taxane solubilizer. PMID:24755470

Nieuweboer, Annemieke J M; Hu, Shuiying; Gui, Chunshan; Hagenbuch, Bruno; Ghobadi Moghaddam-Helmantel, Inge M; Gibson, Alice A; de Bruijn, Peter; Mathijssen, Ron H J; Sparreboom, Alex

2014-06-01

332

Nab-paclitaxel for the management of triple-negative metastatic breast cancer: a case study  

PubMed Central

The optimal sequence of systemic chemotherapy in metastatic breast cancer (MBC) is unknown. We report the case of a woman who was successfully treated with nanoparticle albumin-bound (nab)-paclitaxel for triple negative MBC in our institution. In November 2008, a 48-year-old woman underwent surgical treatment for a triple negative invasive ductal breast cancer and subsequently received adjuvant chemotherapy with fluorouracil/epirubicin/cyclophosphamide and radiotherapy. Sixteen months after surgery, she presented with a left chest wall metastatasis. The patient received combination therapy with conventional paclitaxel (90mg/m² weekly for 3 out of 4 weeks [QW 3/4]) and bevacizumab (10mg/kg every 2 weeks [Q2W]) as first-line treatment for MBC (six cycles; March to September 2010) and achieved a partial response at the metastatic site. Bevacizumab monotherapy was continued until disease progression (April 2011) with the development of a single infraclavicular lymph node metastasis and an increase in the dimensions of the left chest wall lesion. From May to December 2011, the patient received nab-paclitaxel 260mg/m² every 3 weeks (Q3W) as second-line treatment (11 cycles). After three cycles, the left chest wall lesion and the infraclavicular lymph node metastasis were undetectable and the patient was considered to have achieved a complete response. Treatment was well tolerated with no significant toxicity or need for dose reduction. Given our case, here we review the clinical evidence and discuss the potential role of nab-paclitaxel for the treatment of triple negative MBC, a subgroup typically characterized as having aggressive disease and limited treatment options. PMID:25115342

De Placido, Sabino; De Angelis, Carmine

2015-01-01

333

Paclitaxel-loaded PEGylated PLGA-based nanoparticles: In vitro and in vivo evaluation  

Microsoft Academic Search

The purpose of this study was to develop Cremophor® EL-free nanoparticles loaded with Paclitaxel (PTX), intended to be intravenously administered, able to improve the therapeutic index of the drug and devoid of the adverse effects of Cremophor® EL. PTX-loaded PEGylated PLGA-based were prepared by simple emulsion and nanoprecipitation.The incorporation efficiency of PTX was higher with the nanoprecipitation technique. The release

Fabienne Danhier; Nathalie Lecouturier; Benoît Vroman; Christine Jérôme; Jacqueline Marchand-Brynaert; Olivier Feron; Véronique Préat

2009-01-01

334

A Novel Technique for Loading of Paclitaxel-PLGA Nanoparticles onto ePTFE Vascular Grafts  

Microsoft Academic Search

The major cause of hemodialysis vascular access dysfunction (HVAD) is the occurrence of stenosis followed by thrombosis at venous anastomosis sites due to the aggressive development of venous neointimal hyperplasia. Local delivery of antiproliferative drugs may be effective in inhibiting hyperplasia without causing systemic side effects. We have previously demonstrated that paclitaxel-coated expanded poly(tetrafluoroethylene) (ePTFE) grafts, by a dipping method,

Hyun Jung Lim; Hye Yeong Nam; Byung Ha Lee; Dae Joong Kim; Jai Young Ko; Jong-sang Park

2007-01-01

335

The taccalonolides and paclitaxel cause distinct effects on microtubule dynamics and aster formation  

PubMed Central

Background Microtubule stabilizers suppress microtubule dynamics and, at the lowest antiproliferative concentrations, disrupt the function of mitotic spindles, leading to mitotic arrest and apoptosis. At slightly higher concentrations, these agents cause the formation of multiple mitotic asters with distinct morphologies elicited by different microtubule stabilizers. Results We tested the hypothesis that two classes of microtubule stabilizing drugs, the taxanes and the taccalonolides, cause the formation of distinct aster structures due, in part, to differential effects on microtubule dynamics. Paclitaxel and the taccalonolides suppressed the dynamics of microtubules formed from purified tubulin as well as in live cells. Both agents suppressed microtubule dynamic instability, with the taccalonolides having a more pronounced inhibition of microtubule catastrophe, suggesting that they stabilize the plus ends of microtubules more effectively than paclitaxel. Live cell microscopy was also used to evaluate the formation and resolution of asters after drug treatment. While each drug had similar effects on initial formation, substantial differences were observed in aster resolution. Paclitaxel-induced asters often coalesced over time resulting in fewer, larger asters whereas numerous compact asters persisted once they were formed in the presence of the taccalonolides. Conclusions We conclude that the increased resistance of microtubule plus ends to catastrophe may play a role in the observed inability of taccalonolide-induced asters to coalesce during mitosis, giving rise to the distinct morphologies observed after exposure to these agents. PMID:24576146

2014-01-01

336

Model-Based Meta-Analysis for Quantifying Paclitaxel Dose Response in Cancer Patients  

PubMed Central

Model-based meta-analysis of dose response is a sophisticated method to guide dose and regimen selection. In this report, the effects of paclitaxel dose and regimen (weekly or every 3 weeks) on the efficacy and safety in cancer patients were quantified by model-based meta-analysis of 29 monotherapy trials. Logistic regression models were developed to assess the relationship between dose and objective response rate or neutropenia rate. Survival models were developed to assess the relationship between dose and overall survival or progression-free survival. Paclitaxel efficacy (e.g., objective response rate, median overall survival, and progression-free survival) is correlated with average dose per week (mg/m2/week), whereas safety (e.g., neutropenia rate) is correlated with dose per administration (mg/m2). Weekly paclitaxel regimen at 65–80?mg/m2 is supported to have comparable to better efficacy and lower neutropenia incidence than an every-3-week regimen at 175?mg/m2. PMID:24850445

Lu, D; Joshi, A; Li, H; Zhang, N; Ren, M M; Gao, Y; Wada, R; Jin, J Y

2014-01-01

337

[A case of recurrent breast cancer with carcinomatous pleurisy responding to bevacizumab and paclitaxel therapy].  

PubMed

A 57-year-old woman who had undergone muscle-preserving radical mastectomy at the age of 38 presented with a 5 cm mass in front of the breastbone. She was diagnosed as having recurrent breast cancer( estrogen receptor[ ER] positive, progesterone receptor[ PgR] positive, human epidermal growth factor receptor[ HER] -2 negative) by core needle biopsy. She received an aromatase inhibitor (AI) and showed partial response. At the age of 54, PgR status became negative. At the age of 55, the recurrent tumor increased in size, and the patient received 50 Gy of radiation therapy for its treatment and AI administration was continued. At the age of 57, tumor marker levels increased and detailed examination revealed that the recurrent tumor had increased in size and carcinomatous pleurisy was noted. Bevacizumab and paclitaxel therapy was initiated. Tumor marker levels decreased and the pleural fluid disappeared in 2 weeks. After 3 courses, positron emission tomography( PET) -computed tomography( CT) showed a reduction in the tumor size and a decrease in fluorodeoxyglucose (FDG) uptake. Bevacizumab and paclitaxel therapy could be effective for the treatment of patients with recurrent breast cancer with a life-threatening status, after hormone therapy failure. Bevacizumab and paclitaxel could be effective as first- line chemotherapy because of its good treatment efficiency. PMID:24394121

Sato, Yuya; Nakagawa, Tsuyoshi; Sato, Takanobu; Nagahara, Makoto; Sugihara, Kenichi

2013-11-01

338

Long Circulating Lectin Conjugated Paclitaxel Loaded Magnetic Nanoparticles: A New Theranostic Avenue for Leukemia Therapy  

PubMed Central

Amongst all leukemias, Bcr-Abl positive chronic myelogenous leukemia (CML) confers resistance to native drug due to multi drug resistance and also resistance to p53 and fas ligand pathways. In the present study, we have investigated the efficacy of microtubule stabilizing paclitaxel loaded magnetic nanoparticles (pac-MNPs) to ascertain its cytotoxic effect on Bcr-Abl positive K562 cells. For active targeted therapy, pac-MNPs were functionalized with lectin glycoprotein which resulted in higher cellular uptake and lower IC50 value suggesting the efficacy of targeted delivery of paclitaxel. Both pac-MNPs and lectin conjugated pac-MNPs have a prolonged circulation time in serum suggesting increased bioavailability and therapeutics index of paclitaxel in vivo. Further, the molecular mechanism pertaining to pac-induced cytotoxicity was analyzed by studying the involvement of different apoptotic pathway proteins by immunoblotting and quantitative PCR. Our study revealed simultaneous activation of JNK pathway leading to Bcr-Abl instability and the extrinsic apoptotic pathway after pac-MNPs treatment in two Bcr-Abl positive cell lines. In addition, the MRI data suggested the potential application of MNPs as imaging agent. Thus our in vitro and in vivo results strongly suggested the pac-MNPs as a future prospective theranostic tool for leukemia therapy. PMID:22110595

Singh, Abhalaxmi; Dilnawaz, Fahima; Sahoo, Sanjeeb Kumar

2011-01-01

339

[Two advanced gastric cancer cases with peritoneal metastases successfully treated by s-1/paclitaxel combination therapy].  

PubMed

Two unresectable advanced gastric cancer cases with peritoneal metastases were successfully treated by the combination therapy of S-1 and paclitaxel. S-1 (1.25m(2): 80 mg/day, 1.25m(2)-1.50m(2)<:120 mg/day) was administered orally for 14 consecutive days followed by 14 days rest and a 2-hour infusion of paclitaxel (50 mg/m(2)) was administered on day 1 and 15 of each course. Treatment was repeated every 4 weeks unless disease progression or severe adverse effects were observed. Case 1: 65-year-old male (performance status: PS 3) with type 1 gastric cancer with malignant ascites. Case 2: 66-year-old male (PS3) with peritoneal metastases whose primary gastric lesion was surgically resected. Partial response was obtained in the former and complete response in the latter. Combination therapy of S-1 and paclitaxel can be highly recommended for patients with inoperable gastric cancer with poor PS. PMID:19542719

Ina, Kenji; Furuta, Ryuichi; Kataoka, Takae; Nishio, Tomoko; Nagao, Seiji; Kayukawa, Satoshi; Masaki, Ayako; Ando, Takafumi; Goto, Hidemi

2009-06-01

340

Solubility enhancement of paclitaxel using a linear-dendritic block copolymer.  

PubMed

The solubilising capacities of micelles of a linear-dendritic copolymer (BE-PAMAM), formed by conjugating the poly(butylene oxide) (B)-poly(ethylene oxide) (E) block copolymer B16E42 (BE) with a G2 PAMAM dendrimer, have been compared with those of the diblock copolymer B16E42 for the anti-cancer drug paclitaxel. The BE-PAMAM copolymer showed a greater solubility enhancement than BE under equivalent conditions. Drug-loading efficiency was improved using a solvent-loading method compared with the conventional solution-loading method. The solubility of paclitaxel was increased 3700-fold by micellar encapsulation in a 2% (w/v) BE-PAMAM copolymer solution at 37°C using this solubilisation technique. Dynamic light scattering and transmission electron microscopy studies indicated a transition of spherical to worm-like micelles of the BE copolymer induced by the encapsulation of drug molecules. A sustained release of encapsulated drug was observed, with approximately 80% and 60% paclitaxel being released from 2% (w/v) solutions of BE and BE-PAMAM respectively after 24h of dialysis at 37°C. PMID:23651641

Zhou, Zhengyuan; D'Emanuele, Antony; Attwood, David

2013-08-16

341

Dose-Dense Epirubicin and Cyclophosphamide Followed by Weekly Paclitaxel in Node-Positive Breast Cancer  

PubMed Central

Background. Adding taxanes to anthracycline-based adjuvant chemotherapy has shown significant improvement in node-positive breast cancer patients but the optimal dose schedule has still remained undetermined. Objectives. The feasibility of dose-dense epirubicin in combination with cyclophosphamide (EC) followed by weekly paclitaxel as adjuvant chemotherapy in node-positive breast cancer patients was investigated. Methods. All patients were treated with epirubicin (100?mg/m2) and cyclophosphamide (600?mg/m2) every two weeks for four cycles with daily Pegfilgrastim (G-CSF) that was administered 3–10 days after each cycle of epirubicin and cyclophosphamide infusion which followed by (80?mg/m2) paclitaxel for twelve consecutive weeks. Results. Sixty consecutive patients were analyzed, of whom 57 patients (95%) completed the regimen and no case of toxicity-related death was observed. Grade 3/4 hematologic toxicity was uncommon and the most common grade 3/4 nonhematological adverse event was neuropathy disorders. Conclusions. Dose-dense epirubicin and cyclophosphamide followed by weekly paclitaxel with G-CSF support is a well-tolerated and feasible regimen in node-positive breast cancer patients without serious complications. PMID:25276426

Mirzaei, Hamid Reza; Mohammadi Yeganeh, Ladan; Jafari Naeini, Sepideh; Bikdeli, Pegah; Hajian, Parastoo

2014-01-01

342

Involvement of the chemokine CCL3 and the purinoceptor P2X7 in the spinal cord in paclitaxel-induced mechanical allodynia  

PubMed Central

Background Paclitaxel is an effective chemotherapeutic agent widely used for the treatment of solid tumors. The major dose-limiting toxicity of paclitaxel is peripheral neuropathy. The mechanisms underlying the development and maintenance of paclitaxel-induced peripheral neuropathy are still unclear, and there are no currently established effective treatments. Accumulating evidence in models of neuropathic pain in which peripheral nerves are lesioned has implicated spinal microglia and chemokines in pain hypersensitivity, but little is know about their roles in chemotherapy-induced peripheral neuropathy. In the present study, we investigated the role of CC-chemokine ligand 3 (CCL3) in the spinal cord in the development and maintenance of mechanical allodynia using a rat model of paclitaxel-induced neuropathy. Findings Repeated intravenous administration of paclitaxel induced a marked decrease in paw withdrawal threshold in response to mechanical stimulation (mechanical allodynia). In these rats, the number of microglia in the spinal dorsal horn (SDH) was significantly increased. Paclitaxel-treated rats showed a significant increase in the expression of mRNAs for CCL3 and its receptor CCR5 in the SDH. Intrathecal administration of a CCL3-neutralizing antibody not only attenuated the development of paclitaxel-induced mechanical allodynia but also reversed its maintenance. Paclitaxel also upregulated expression of purinoceptor P2X7 receptors (P2X7Rs), which have been implicated in the release of CCL3 from microglia, in the SDH. The selective P2X7R antagonist A438079 had preventive and reversal effects on paclitaxel-induced allodynia. Conclusions Our findings suggest a contribution of CCL3 and P2X7Rs in the SDH to paclitaxel-induced allodynia and may provide new therapeutic targets for paclitaxel-induced painful neuropathy. PMID:25127716

2014-01-01

343

miR-17-5p Downregulation Contributes to Paclitaxel Resistance of Lung Cancer Cells through Altering Beclin1 Expression  

PubMed Central

Non- small- cell lung cancer (NSCLC) is one of the most leading causes of cancer-related deaths worldwide. Paclitaxel based combination therapies have long been used as a standard treatment in aggressive NSCLCs. But paclitaxel resistance has emerged as a major clinical problem in combating non-small-cell lung cancer and autophagy is one of the important mechanisms involved in this phenomenon. In this study, we used microRNA (miRNA) arrays to screen differentially expressed miRNAs between paclitaxel sensitive lung cancer cells A549 and its paclitaxel-resistant cell variant (A549-T24). We identified miR-17-5p was one of most significantly downregulated miRNAs in paclitaxel-resistant lung cancer cells compared to paclitaxel sensitive parental cells. We found that overexpression of miR-17-5p sensitized paclitaxel resistant lung cancer cells to paclitaxel induced apoptotic cell death. Moreover, in this report we demonstrated that miR-17-5p directly binds to the 3?-UTR of beclin 1 gene, one of the most important autophagy modulator. Overexpression of miR-17-5p into paclitaxel resistant lung cancer cells reduced beclin1 expression and a concordant decease in cellular autophagy. We also observed similar results in another paclitaxel resistant lung adenosquamous carcinoma cells (H596-TxR). Our results indicated that paclitaxel resistance of lung cancer is associated with downregulation of miR-17-5p expression which might cause upregulation of BECN1 expression. PMID:24755562

Chatterjee, Abhisek; Chattopadhyay, Dhrubajyoti; Chakrabarti, Gopal

2014-01-01

344

Molecular description of evolving paclitaxel resistance in the SKOV-3 human ovarian carcinoma cell line.  

PubMed

Ovarian cancer is currently the most lethal gynecological malignancy in the United States. Although effective therapies exist, the acquisition of multidrug resistance within persisting tumor cells renders curative therapies elusive for the majority of women with ovarian cancer. In an attempt to better define the evolution of paclitaxel resistance, three SKOV-3 sublines were selected during successive rounds of exposure to increasing paclitaxel concentrations. The sublines were selected to represent early (0.003 micro M), intermediate (0.03 micro M), and late (0.3 micro M) paclitaxel resistance. RNA from these cell lines, SKOV-3(0.003TR), SKOV-3(0.03TR), and SKOV-3(0.3TR), as well as the parent cell line SKOV-3, was analyzed by cDNA array to evaluate transcript expression profiles. Arrays were performed using Affymetrix HG-U95Av2 arrays, which contain probes for approximately 9600 known human genes. Signal intensities were calculated by Microarray Suite 5.0 (Affymetrix, Santa Clara, CA). Expression patterns were analyzed by Affymetrix Data Mining Tool 3.0 with filtering of expression patterns for fold change in expression (maximum divided by minimum expression value/gene) and for variation of expression (maximum minus minimum expression value/gene). This analysis dismissed approximately 11,000 of approximately 12,000 expression patterns. The remaining approximately 1000 expression patterns were normalized and segregated into 20 partitions of a self-organizing map (SOM). The resulting SOM discriminates between genes, which are differentially expressed in early versus intermediate versus late paclitaxel resistance. For example, multidrug resistance 1 transcript expression is not elevated in SKOV-3(0.003TR) as compared with parental SKOV-3 but demonstrates elevated expression in SKOV-3(0.03TR) and SKOV-3(0.3TR). In contrast, SOM analysis demonstrates early (SKOV-3(0.003TR)) transcriptional changes in a wide variety of genes, including gene families involved in cell growth/maintenance, cell structure, signal transduction, and inflammatory response. The use of array analysis with SOMs in sublines with progressive paclitaxel resistance can successfully define an evolution of resistance. Such an analysis may be useful at defining candidate gene families involved in the early-drug resistance phenotype. PMID:12727840

Lamendola, Diana E; Duan, Zhenfeng; Yusuf, Rushdia Z; Seiden, Michael V

2003-05-01

345

Folic acid-coupled nano-paclitaxel liposome reverses drug resistance in SKOV3/TAX ovarian cancer cells.  

PubMed

Chemotherapy could be used as an effective treatment for ovarian cancer and subsequent peritoneal metastasis. Administration of chemoagents in a targeted manner may bring the advantage of higher efficiency and lower drug resistance. In the present study, folate receptor (FR)-targeted nano-paclitaxel formulations were generated and tested for cytotoxicity in a peritoneal xenograft model of paclitaxel-resistant ovarian cancer and SKOV3/TAX cell lines. Immunocytochemical staining confirmed the expression of FR in both SKOV3 and SKOV3/TAX cells. The enrichment of the folic acid-coupled PEGylated nano-paclitaxel liposome (FA-NP) in FR-positive cells was visualized with fluorescence. The uptake of the FA-NP peaked at 4 h and was more robust than nontargeted PEGylated nano-paclitaxel liposome (NP). FA-NP but not NP markedly inhibited the growth of ovarian cancer cells and induced a two-fold increase in the doubling time. The cytotoxic effects of FA-NP were more potent than NP in both SKOV3 cells [50% of inhibition concentration (IC50), 5.67 vs. 50.2 ?g/ml, FA-NP vs. NP] and SKOV3/TAX cells (IC50, 0.38 vs. >200 ?g/ml, FA-NP vs. NP). FA-NP caused more G2-M cell cycle arrest and apoptotic changes in ovarian cancer cells than NP or regular paclitaxel. However, these effects were blunted in the presence of free FA, which competitively inhibited the receptor-mediated uptake of FA-NP particles. Intraperitoneal (i.p.) administration of FA-NP but not regular paclitaxel, NP, or vehicle significantly prolonged the survival and reduced tumor nodule number (2.9±0.3) in BALB/c nude mice. FA-NP also markedly enhanced the percentage of apoptotic cells in peritoneal xenografts of paclitaxel-resistant ovarian cancer cells (44.6±8.5 vs. 3.2±1.1% for vehicle, 22.4±5.9% for regular paclitaxel, and 35.2±7.7% for NP; P<0.05). However, intravenous administration of FA-NP at the same dose failed to induce apoptosis (20.1±6.2%; P<0.05) and inhibit tumor nodule number to the same extent as intraperitoneal administration. FA-NP reversed the drug resistance in paclitaxel-resistant SKOV3/TAX ovarian cancer cells both in vitro and in vivo. Localized and targeted administration of the FR-targeted chemoagents might prolong the survival time in patients with drug-resistant ovarian cancer. PMID:24275314

Tong, Lingxia; Chen, Wei; Wu, Jing; Li, Hongxia

2014-03-01

346

Cancer cell sensitization and improved treatment efficacy by combined sodium butyrate and paclitaxel formulations is cancer-type specific.  

PubMed

We queried whether cancer treatment by combinations of paclitaxel and butyrate - free or formulated in drug delivery systems - can improve therapeutic responses compared to each drug alone. Combination treatments were conducted with HT-29 and HeLa cells, as representatives of differentiation-induced and cell-death-induced cancer lines, respectively. Pre-treatment of the HT-29 cells with butyrate (at doses inducing differentiation), followed by butyrate+paclitaxel generated changes in cell cycle profile, increased the level of dead cells beyond that of each drug alone, and allowed reduction in paclitaxel doses. A similar combination treatment of HeLa cells was detrimental, indicating that whether the combination is beneficial or not is cancer-type specific. We hypothesize that while butyrate-treated HT-29 cells became sensitive to paclitaxel-induced Fas-mediated apoptosis, butyrate-adapted HeLa cells became apoptosis-resistant. We next tested the same drug combination on HT-29 cells, but each drug in a specific tumor-targeted carrier. The combination of drug carriers outperformed an equidose combination of the free drugs, showing potential to achieve high therapeutic responses (even in drug-resistant cells) at significantly lower and detergent-free paclitaxel doses, which should allow for reduction in adverse effects and risks of toxicity. PMID:24370842

Rivkin, Ilia; Cohen, Keren; Bod, Tal; Argov, Mirit; Margalit, Rimona

2014-01-30

347

Pluronic-poly (acrylic acid)-cysteine/Pluronic L121 mixed micelles improve the oral bioavailability of paclitaxel.  

PubMed

Abstract The aim of the study is to synthesize a thiolated Pluronic copolymer, Pluronic-poly (acrylic acid)-cysteine copolymer, to construct a mixed micelle system with the Pluronic-poly (acrylic acid)-cysteine copolymer and Pluronic L121 (PL121) and to evaluate the potential of these mixed micelles as an oral drug delivery system for paclitaxel. Compared with Pluronic-poly (acrylic acid)-cysteine micelles, drug-loading capacity of Pluronic-poly (acrylic acid)-cysteine/PL121 mixed micelles was increased from 0.4 to 2.87%. In vitro release test indicated that Pluronic-poly (acrylic acid)-cysteine/PL121 mixed micelles exhibited a pH sensitivity. The permeability of drug-loaded micelles in the intestinal tract was studied with an in situ perfusion method in rats. The presence of verapamil and Pluronic both improved the intestinal permeability of paclitaxel, which further certified the inhibition effect of thiolated Pluronic on P-gp. In pharmacokinetic study, the area under the plasma concentration-time curve (AUC0??) of paclitaxel-loaded mixed micelles was four times greater than that of the paclitaxel solution (p?paclitaxel. PMID:23971495

Zhao, Yanli; Li, Yanli; Ge, Jianjun; Li, Na; Li, Ling-Bing

2014-11-01

348

Spotlight on Paclitaxel in Ovarian Cancer The full text of this article was published in PharmacoEconomics 2001; 19 (12): 1227-1259  

Microsoft Academic Search

Paclitaxel belongs to the group of antitumor agents called the taxanes. Its efficacy in advanced ovarian cancer has been established in large, randomized phase III clinical trials. When used in combination with cisplatin for first-line treatment of advanced ovarian cancer, it is superior to cyclophosphamide\\/cisplatin, with gains in median survival of around 1 year. Paclitaxel plus carboplatin has similar efficacy

Melissa Young; Greg L. Plosker

2002-01-01

349

Characterization of cell death events induced by anti-neoplastic drugs cisplatin, paclitaxel and 5-fluorouracil on human hepatoma cell lines: Possible mechanisms of cell resistance  

Microsoft Academic Search

Two different hepatoma cell lines were incubated for 48h with chemotherapeutic drugs cisplatin, paclitaxel and 5-FU to determine their ability to induce cytotoxicity and DNA fragmentation as well as to modify the expression of some cell death-related genes that could be involved in the resistance to therapy. We observed that cisplatin and paclitaxel induced cytotoxicity, but significant differences between both

O. Brenes; F. Arce; O. Gätjens-Boniche; C. Díaz

2007-01-01

350

Sequence dependent effect of paclitaxel on gemcitabine metabolism in relation to cell cycle and cytotoxicity in non-small-cell lung cancer cell lines  

PubMed Central

Gemcitabine and paclitaxel are active agents in the treatment of non-small-cell lung cancer (NSCLC). To optimize treatment drug combinations, simultaneously and 4 and 24 h intervals, were studied using DNA flow cytometry and multiple drug effect analysis in the NSCLC cell lines H460, H322 and Lewis Lung. All combinations resulted in comparable cytotoxicity, varying from additivity to antagonism (combination index: 1.0–2.6). Gemcitabine caused a S (48%) and G1 (64%) arrest at IC-50 and 10 × IC-50 concentrations, respectively. Paclitaxel induced G2/M arrest (70%) which was maximal within 24 h at 10 × IC-50. Simultaneous treatment increased S-phase arrest, while at the 24 h interval after 72 h the first drug seemed to dominate the effect. Apoptosis was more pronounced when paclitaxel preceded gemcitabine (20% for both intervals) as compared to the reverse sequence (8%, P = 0.173 for the 4 h and 12%, P = 0.051 for the 24 h time interval). In H460 cells, paclitaxel increased 2-fold the accumulation of dFdCTP, the active metabolite of gemcitabine, in contrast to H322 cells. Paclitaxel did not affect deoxycytidine kinase levels, but ribonucleotide levels increased possibly explaining the increase in dFdCTP. Paclitaxel did not affect gemcitabine incorporation into DNA, but seemed to increase incorporation into RNA. Gemcitabine almost completely inhibited DNA synthesis in both cell lines (70–89%), while paclitaxel had a minor effect and did not increase that of gemcitabine. In conclusion, various gemcitabine–paclitaxel combinations did not show sequence dependent cytotoxic effects; all combinations were not more than additive. However, since paclitaxel increased dFdCTP accumulation, gemcitabine incorporation into RNA and the apoptotic index, the administration of paclitaxel prior to gemcitabine might be favourable as compared to reversed sequences. © 2000 Cancer Research Campaign PMID:10993656

Kroep, J R; Giaccone, G; Tolis, C; Voorn, D A; Loves, W J P; Groeningen, C J van; Pinedo, H M; Peters, G J

2000-01-01

351

Successful Chemotherapy with Nab-Paclitaxel in a Heavily Treated Non-Small Cell Lung Cancer Patient: A Case Report  

PubMed Central

Non-small cell lung cancer (NSCLC) accounts for the majority of all lung cancers. A 69-year-old female with postoperatively recurrent NSCLC was treated weekly with nanoparticle-albumin-bound paclitaxel (nab-paclitaxel) monotherapy every 4 weeks as a tenth line chemotherapy, and stable disease was achieved by seven cycles of this regimen. The patient developed grade 4 neutropenia and grade 3 leukopenia, but none of the other toxicities, including febrile neutropenia and peripheral neuropathy, were severe, and thus she was able to tolerate this salvage chemotherapy. To our knowledge this is the first report of the efficacy of nab-paclitaxel monotherapy in a heavily treated NSCLC patient. PMID:25076891

Ishihara, Mikiko; Igawa, Satoshi; Maki, Sachiyo; Harada, Shinya; Kusuhara, Seiichiro; Niwa, Hideyuki; Otani, Sakiko; Sasaki, Jiichiro; Jiang, Shi-Xu; Masuda, Noriyuki

2014-01-01

352

Inhibition of Lipolysis by Mercaptoacetate and Etomoxir Specifically Sensitize Drug-Resistant Lung Adenocarcinoma Cell to Paclitaxel  

PubMed Central

Chemoresistance is a major cause of treatment failure in patients with lung cancer. Although the extensive efforts have been made in overcoming chemoresistance, the underlying mechanisms are still elusive. Cancer cells reprogram cellular metabolism to satisfy the demands of malignant phenotype. To reveal roles of cancer metabolism in regulating chemoresistance, we profiled the metabolic characteristics in paclitaxel-resistant lung cancer cells by flux assay. Glucose and oleate metabolism were significantly different between resistant and non-resistant cells. In addition, targeting metabolism as a strategy to overcome drug resistance was investigated using specific metabolic inhibitors. Inhibition of glycolysis and oxidative phosphorylation by 2-deoxyglucose and malonate, respectively, potentiated the effects of paclitaxel on nonresistant lung adenocarcinoma cells but not paclitaxel-resistant cells. By contrast, inhibition of lipolysis by mercaptoacetate or etomoxir synergistically inhibited drug-resistant lung adenocarcinoma cell proliferation. We conclude that lipolysis inhibition potentially be a therapeutic strategy to overcome drug resistance in lung cancer. PMID:24040298

Zhou, Xiang; Zhang, Teng; Zhao, Li; Miao, Ping; Song, Shaoli; Sun, Xiaoguang; Liu, Jianjun; Zhao, Xiaoping; Huang, Gang

2013-01-01

353

Cellular aggregation is a key parameter associated with long term variability in paclitaxel accumulation in Taxus suspension cultures  

PubMed Central

Plant cell cultures provide a renewable source for synthesis and supply of commercially valuable plant-derived products, particularly for secondary metabolites. However, instability in product yields over multiple passages has hampered the efficient and sustainable use of this technology. Paclitaxel accumulation in Taxus cell suspension culture was quantified over multiple passages and correlated to mean aggregate size, extracellular sugar level, ploidy, and cell cycle distribution. Paclitaxel levels varied approximately 6.9-fold over the six-month timeframe investigated. Of all of the parameters examined, only mean aggregate size correlated with paclitaxel accumulation, where a significant negative correlation (r = ? 0.75, p < 0.01) was observed. These results demonstrate the relevance of measuring, and potentially controlling, aggregate size during long term culture passages, particularly for plant suspensions where industrially relevant secondary metabolites are not pigmented to enable rapid culture selection. PMID:23439858

Patil, Rohan A.; Kolewe, Martin E.; Roberts, Susan C.

2012-01-01

354

Mechanisms of tissue uptake and retention of paclitaxel-coated balloons: impact on neointimal proliferation and healing  

PubMed Central

Background The efficacy of paclitaxel-coated balloons (PCB) for restenosis prevention has been demonstrated in humans. However, the mechanism of action for sustained drug retention and biological efficacy following single-time drug delivery is still unknown. Methods and results The pharmacokinetic profile and differences in drug concentration (vessel surface vs arterial wall) of two different paclitaxel coating formulations (3?µg/mm2) displaying opposite solubility characteristics (CC=crystalline vs AC=amorphous) were tested in vivo and compared with paclitaxel-eluting stents (PES). Also, the biological effect of both PCB formulations on vascular healing was tested in the porcine coronary injury model. One hour following balloon inflation, both formulations achieved similar arterial paclitaxel levels (CC=310 vs AC=245?ng/mg; p=NS). At 24?h, the CC maintained similar tissue concentrations, whereas the AC tissue levels declined by 99% (p<0.01). At this time point, arterial levels were 20-fold (CC) and 5-fold (AC) times higher compared to the PES group (p<0.05). At 28?days, arterial levels retained were 9.2% (CC) and 0.04% (AC, p<0.01) of the baseline levels. Paclitaxel concentration on the vessel surface was higher in the CC at 1 (CC=36.7% vs AC=13.1%, p<0.05) and 7?days (CC=38.4% vs AC=11%, p<0.05). In addition, the CC induced higher levels of neointimal inhibition, fibrin deposition and delayed healing compared with the AC group. Conclusions The presence of paclitaxel deposits on the vessel surface driving diffusion into the arterial tissue in a time-dependent fashion supports the mechanism of action of PCB. This specific pharmacokinetic behaviour influences the patterns of neointimal formation and healing. PMID:25332821

Granada, Juan F; Stenoien, Mark; Buszman, Piotr P; Tellez, Armando; Langanki, Dan; Kaluza, Greg L; Leon, Martin B; Gray, William; Jaff, Michael R; Schwartz, Robert S

2014-01-01

355

First total synthesis of (5Z,9Z)-(?)-2-methoxy-5,9-octadecadienoic acid, a marine derived methoxylated analog of taxoleic acid  

PubMed Central

The first total synthesis for the sponge derived (5Z,9Z)-(±)-2-methoxy-5,9-octadecadienoic acid, an analog of taxoleic acid, was accomplished in seven steps and in a 10% overall yield. It was again corroborated that the best strategy to prepare these cis,cis dimethylene interrupted double bonds is the double-alkyne bromide coupling reaction of 1,5-hexadiyne, which provides the advantage of achieving a 100% cis stereochemical purity for both double bonds after hydrogenation under Lindlar conditions. The ?-methoxy functionality was best prepared via the Mukaiyama reaction of (4Z,8Z)-heptadecadienal with trimethylsilyl cyanide and triethylamine followed by acid hydrolysis. Selective methylation of the hydroxyl group of (5Z,9Z)-(±)-2-hydroxy-5,9-octadecadienoic acid was achieved with sodium hydride/methyl iodide when tetrahydrofuran was used as solvent. Complete spectral data is presented, for the first time, for this unusual marine ?-methoxylated fatty acid. PMID:18761005

Carballeira, Nestor M.; O'Neill, Rosann; Silva, Diana

2008-01-01

356

Novel biocompatible intraperitoneal drug delivery system increases tolerability and therapeutic efficacy of paclitaxel in a human ovarian cancer xenograft model  

Microsoft Academic Search

Purpose  We compared the safety, toxicity, biocompatibility and anti-tumour efficacy of a novel chitosan-egg phosphatidylcholine (ePC)\\u000a implantable drug delivery system that provides controlled and sustained release of paclitaxel (PTXePC) versus commercial paclitaxel formulated in Cremophor EL (PTXCrEL).\\u000a \\u000a \\u000a \\u000a Methods  Toxicity studies were conducted in healthy CD-1 female mice, whereas efficacy studies were performed in the SKOV-3 xenograft\\u000a model of ovarian cancer. Treatments consisted

Vessela Vassileva; Justin Grant; Raquel De Souza; Christine Allen; Micheline Piquette-Miller

2007-01-01

357

Comparison of Cell Death-inducing Effect of Novel Taxane SB-T-1216 and Paclitaxel in Breast Cancer Cells  

PubMed Central

Background In this study, the effect of novel taxane SB-T-1216 and paclitaxel were compared on drug-sensitive MDA-MB-435 and drug-resistant NCI/ADR-RES human breast cancer cells. Materials and Methods Cell growth and survival were evaluated after 96-hour incubation with tested concentrations of taxanes. The effect on the formation of microtubule bundles was assessed employing fluorescence microscopy and on the cell cycle employing flow cytometric analysis. The activity of caspases was assessed employing commercial colorimetric kits. Results The IC50 (concentration resulting in 50% of living cells in comparison with the control) of SB-T-1216 in drug-sensitive cells was 0.6 nM versus 1 nM for paclitaxel. However, the IC50 of SB-T-1216 in drug-resistant cells was 1.8 nM versus 300 nM for paclitaxel. Both SB-T-1216 and paclitaxel at death-inducing concentrations induced the formation of microtubule bundles in drug-sensitive as well as drug-resistant cells. Cell death induced in drug-sensitive and drug-resistant cells by paclitaxel was associated with the accumulation of cells in the G2/M phase. On the contrary, cell death induced by SB-T-1216 took place without the accumulation of cells in the G2/M phase but with a decreased number of G1 cells and the accumulation of hypodiploid cells. Both SB-T-1216 and paclitaxel activated caspase-3, caspase-9, caspase-2 and caspase-8 in drug-sensitive as well as drug-resistant cells. Conclusion Cell death induced by both paclitaxel and novel taxane SB-T-1216 in breast cancer cells is associated with caspase activation and with the formation of interphase microtubule bundles. Novel taxane SB-T-1216, but not paclitaxel, seems to be capable of inducing cell death without the accumulation of cells in the G2/M phase. PMID:19661300

KOVAR, JAN; EHRLICHOVA, MARIE; SMEJKALOVA, BARBORA; ZANARDI, ILARIA; OJIMA, IWAO; GUT, IVAN

2010-01-01

358

Neurosteroid 3?-androstanediol efficiently counteracts paclitaxel-induced peripheral neuropathy and painful symptoms.  

PubMed

Painful peripheral neuropathy belongs to major side-effects limiting cancer chemotherapy. Paclitaxel, widely used to treat several cancers, induces neurological symptoms including burning pain, allodynia, hyperalgesia and numbness. Therefore, identification of drugs that may effectively counteract paclitaxel-induced neuropathic symptoms is crucial. Here, we combined histopathological, neurochemical, behavioral and electrophysiological methods to investigate the natural neurosteroid 3?-androstanediol (3?-DIOL) ability to counteract paclitaxel-evoked peripheral nerve tissue damages and neurological symptoms. Prophylactic or corrective 3?-DIOL treatment (4 mg/kg/2 days) prevented or suppressed PAC-evoked heat-thermal hyperalgesia, cold-allodynia and mechanical allodynia/hyperalgesia, by reversing to normal, decreased thermal and mechanical pain thresholds of PAC-treated rats. Electrophysiological studies demonstrated that 3?-DIOL restored control values of nerve conduction velocity and action potential peak amplitude significantly altered by PAC-treatment. 3?-DIOL also repaired PAC-induced nerve damages by restoring normal neurofilament-200 level in peripheral axons and control amount of 2',3'-cyclic-nucleotide-3'-phosphodiesterase in myelin sheaths. Decreased density of intraepidermal nerve fibers evoked by PAC-therapy was also counteracted by 3?-DIOL treatment. More importantly, 3?-DIOL beneficial effects were not sedation-dependent but resulted from its neuroprotective ability, nerve tissue repairing capacity and long-term analgesic action. Altogether, our results showing that 3?-DIOL efficiently counteracted PAC-evoked painful symptoms, also offer interesting possibilities to develop neurosteroid-based strategies against chemotherapy-induced peripheral neuropathy. This article shows that the prophylactic or corrective treatment with 3?-androstanediol prevents or suppresses PAC-evoked painful symptoms and peripheral nerve dysfunctions in rats. The data suggest that 3?-androstanediol-based therapy may constitute an efficient strategy to explore in humans for the eradication of chemotherapy-induced peripheral neuropathy. PMID:24260511

Meyer, Laurence; Patte-Mensah, Christine; Taleb, Omar; Mensah-Nyagan, Ayikoe Guy

2013-01-01

359

Paclitaxel-coated balloons in refractory nonanastomostic airway stenosis following lung transplantation.  

PubMed

Airway stenosis represents the commonest airway complication following lung transplantation, affecting between 7% and 18% of patients. Existing treatment options offer limited efficacy and can cause additional patient morbidity. Paclitaxel-coated balloons (PCB) have proved effective in managing postinterventional coronary artery re-stenosis. In a first-in-man study, we evaluated similar PCBs in refractory nonanastomotic airway stenosis in 12 patients. Following a single application, luminal patency was maintained in 50% at 270 days. No significant peri-interventional or early postinterventional complications occurred. Given these encouraging initial findings, further studies appear warranted. PMID:25055720

Greer, M; Fuehner, T; Warnecke, G; Noack, H; Heilmann, T; Haverich, A; Welte, T; Gottlieb, J

2014-10-01

360

Vasculitis resulting from a superficial femoral artery angioplasty with a paclitaxel-eluting balloon.  

PubMed

Drug-eluting balloons (DEBs) coated with the antiproliferative agent paclitaxel may improve primary patency by reducing recurrent luminal stenosis. A proportion of the active drug and excipient coating are known to embolize distally, but until now, there have been no reports of adverse events resulting from their use. We report an unusual case of a painful nodular, biopsy specimen-proven vasculitic rash that afflicted the ipsilateral lower limb of a patient after superficial femoral artery treatment with a DEB. This adverse event may have implications for the use of DEB in this and other vascular territories. PMID:23642919

Thomas, Shannon D; McDonald, Robert R A; Varcoe, Ramon L

2014-02-01

361

Interleukin6 protects against paclitaxel, cisplatin and vincristine-induced neuropathies without impairing chemotherapeutic activity  

Microsoft Academic Search

Purpose  This study was conducted to investigate the potential neuroprotective effect of IL-6 on chemotherapy induced neuropathy (CIN).\\u000a IL-6 was compared to four-methylcatechol (4-MC)-a known inducer of NGF secretion previously shown to exhibit neuroprotective\\u000a effects in CIN models.\\u000a \\u000a \\u000a \\u000a Methods  \\u000a Three CIN models were used; two in rats (cisplatin and vincristine) and one in mice (paclitaxel). IL-6 was delivered in four different

Noelle Callizot; Emile Andriambeloson; Jonathan Glass; Michel Revel; Pamela Ferro; Rocco Cirillo; Pierre-Alain Vitte; Michel Dreano

2008-01-01

362

Cdk2 acts upstream of mitochondrial permeability transition during paclitaxel-induced apoptosis  

Microsoft Academic Search

Sequential activation of cyclin-dependent kinases (Cdks) controls mammalian cell cycle. Here we demonstrate that the upregulation\\u000a of cyclin-dependent kinase 2 (Cdk2) activity coincides with the loss of mitochondrial membrane potential (MMP) in paclitaxel-induced\\u000a apoptosis. Ectopic expression of the dominant negative Cdk2 (Cdk2-dn) and a specific Cdk2 inhibitor, p21\\u000a WAF1\\/CIP1\\u000a , effectively suppresses the loss of MMP, the release of cytochrome

Xiao-Xi Guo; Hanna Kim; Yang Li; Hyungshin Yim; Seung Ki Lee; Ying-Hua Jin

2011-01-01

363

Proteinase-activated receptor 2 sensitizes transient receptor potential vanilloid 1, transient receptor potential vanilloid 4, and transient receptor potential ankyrin 1 in paclitaxel-induced neuropathic pain.  

PubMed

Paclitaxel chemotherapy is limited by a long-lasting painful neuropathy that lacks an effective therapy. In this study, we tested the hypothesis that paclitaxel may release mast cell tryptase, which activates protease-activated receptor 2 (PAR2) and, subsequently, protein kinases A and C, resulting in mechanical and thermal (both heat and cold) hypersensitivity. Correlating with the development of neuropathy after repeated administration of paclitaxel, mast cell tryptase activity was found to be increased in the spinal cord, dorsal root ganglia, and peripheral tissues in mice. FSLLRY-amide, a selective PAR2 antagonist, blocked paclitaxel-induced neuropathic pain behaviors in a dose- and time-dependent manner. In addition, blocking downstream signaling pathways of PAR2, including phospholipase C (PLC), protein kinase A (PKA), and protein kinase C? (PKC), effectively attenuated paclitaxel-induced mechanical, heat, or cold hypersensitivity. Furthermore, sensitized pain response was selectively inhibited by antagonists of transient receptor potential (TRP) V1, TRPV4, or TRPA1. These results revealed specific cellular signaling pathways leading to paclitaxel-induced neuropathy, including the activation of PAR2 and downstream enzymes PLC, PKC?, and PKA and resultant sensitization of TRPV1, TRPV4, and TRPA1. Targeting one or more of these signaling molecules may present new opportunities for the treatment of paclitaxel-induced neuropathy. PMID:21763756

Chen, Y; Yang, C; Wang, Z J

2011-10-13

364

Atractylenolide-I Sensitizes Human Ovarian Cancer Cells to Paclitaxel by Blocking Activation of TLR4/MyD88-dependent Pathway  

PubMed Central

Paclitaxel, a known TLR4 ligand, leads to activation of TLR4/MyD88-dependent pathway that mediates chemoresistance and tumor progression in epithelial ovarian carcinoma (EOC). Atractylenolide-I (AO-I), a novel TLR4-antagonizing agent, inhibits TLR4 signaling by interfering with the binding of LPS or paclitaxel to membrane TLR4 of human leukocytes. In this study, AO-I was found to attenuate paclitaxel-induced protein expression of IL-6, VEGF and survivin, and to enhance early apoptosis and growth inhibition in MyD88+ EOC cells; AO-I was shown to fit into the hydrophobic pocket of human MD-2 and to partially overlap with the binding site of paclitaxel by docking simulations, suggesting that AO-I may block the MD-2-mediated TLR4/MyD88-dependent paclitaxel signaling in MyD88+ EOC cells. Therefore, AO-I could significantly sensitize the response of MyD88+ EOC cells to paclitaxel by blocking MD-2-mediated TLR4/MyD88 signaling, and that AO-I-paclitaxel combination could be a promising strategy for the treatment of EOC with a functional TLR4/MyD88/NF-?B pathway. PMID:24452475

Huang, Jian-Ming; Zhang, Guo-Nan; Shi, Yu; Zha, Xiao; Zhu, Yi; Wang, Miao-Miao; Lin, Qing; Wang, Wen; Lu, Hai-Yan; Ma, Shi-Qi; Cheng, Jia; Deng, Bi-Fang

2014-01-01

365

Molecular mechanisms of paclitaxel and NM-3 on human gastric cancer in a severe combined immune deficiency mice orthotopic implantation model  

PubMed Central

AIM: To explore the molecular mechanisms of action of paclitaxel and NM-3 on human gastric cancer in severe combined immune deficiency (SCID) mice. METHODS: Human gastric cancer cells SGC-7901 were implanted into SCID mice and mice were treated with paclitaxel and NM-3. The effects of paclitaxel and NM-3 on apoptosis of human gastric cancer cells were analyzed using flow cytometry, TUNEL assays, and DNA fragment analyses. RESULTS: Apoptosis of SGC-7901 cells was successfully induced by paclitaxel, NM-3, and the combination of paclitaxel and NM-3 24 h after injection as shown by the presence of apoptotic hypodiploid peaks on the flow cytometer before G1-S and a characteristic apoptotic band pattern in the DNA electrophoresis. The apoptotic rate detected by TUNEL assay was found to be significantly higher in the paclitaxel/NM-3 compared to the control group (38.5% ± 5.14% vs 13.2% ± 1.75%, P < 0.01). CONCLUSION: Paclitaxel in combination with NM-3 is able to induce apoptosis of the human gastric cancer cells in SCID mice effectively and synergistically. PMID:17696236

Zhu, Jin-Shui; Song, Ming-Quan; Chen, Guo-Qiang; Li, Qin; Sun, Qun; Zhang, Qiang

2007-01-01

366

Synergistic cytotoxicity of oncolytic reovirus in combination with cisplatin-paclitaxel doublet chemotherapy.  

PubMed

Oncolytic reovirus is currently under active investigation in a range of tumour types. Early phase studies have shown that this agent has modest monotherapy efficacy and its future development is likely to focus on combination regimens with cytotoxic chemotherapy. Indeed, phase I/II clinical trials have confirmed that reovirus can be safely combined with cytotoxic drugs, including a platin-taxane doublet regimen, which is currently being tested in a phase III clinical trial in patients with relapsed/metastatic head and neck cancer. Therefore, we have tested this triple (reovirus, cisplatin, paclitaxel) combination therapy in a panel of four head and neck cancer cell lines. Using the combination index (CI) method, the triple therapy demonstrated synergistic cytotoxicity in vitro in both malignant and non-malignant cell lines. In head and neck cancer cell lines, this was associated with enhanced caspase 3 and 7 cleavage, but no increase in viral replication. In vitro analyses confirmed colocalisation of markers of reovirus infection and caspase 3. Triple therapy was significantly more effective than reovirus or cisplatin-paclitaxel in athymic nude mice. These data suggest that the combination of reovirus plus platin-taxane doublet chemotherapy has significant activity in head and neck cancer and underpin the current phase III study in this indication. PMID:22895509

Roulstone, V; Twigger, K; Zaidi, S; Pencavel, T; Kyula, J N; White, C; McLaughlin, M; Seth, R; Karapanagiotou, E M; Mansfield, D; Coffey, M; Nuovo, G; Vile, R G; Pandha, H S; Melcher, A A; Harrington, K J

2013-05-01

367

Two Cases of Mastectomy after Paclitaxel + Bevacizumab Therapy for Locally Advanced Breast Cancer  

PubMed Central

Introduction Locally advanced breast cancer (LABC) deteriorates the quality of life (QOL) of the affected patients. Combination chemotherapy or extended chemotherapy is considered to help to shrink local lesions. Case 1 A 71-year-old female with a history of tympanitis and cystitis with methicillin-resistant Staphylococcus aureus (MRSA) visited our hospital. There was a tumor of 7 cm in diameter in her right breast with skin ulceration. Paclitaxel + bevacizumab therapy was started, and after five cycles of therapy, a mastectomy with axillary dissection was performed. Chemotherapy with anthracycline was avoided for fear of activating the MRSA. After the operation, the patient's wound opened. However, it naturally epithelialized. Case 2 A 41-year-old female visited our hospital due to a tumor of 8 cm in diameter in her right breast with skin ulceration. Four cycles of paclitaxel + bevacizumab therapy were started, and her tumor almost disappeared during the first cycle. Then, doxorubicin + cyclophosphamide therapy was performed for four cycles, and a mastectomy with axillary dissection was performed. Her postoperative course was good. Discussion Chemotherapy with bevacizumab or extended chemotherapy is generally not considered to contribute to a survival improvement. However, such therapy contributes in increasing the response to chemotherapy, and should be considered for patients with LABC to shrink the local lesions and improve the QOL. PMID:24932175

Shinoda, Chika; Mori, Ryutaro; Nagao, Yasuko

2014-01-01

368

Effects of Paclitaxel on EGFR Endocytic Trafficking Revealed Using Quantum Dot Tracking in Single Cells  

PubMed Central

Paclitaxel (PTX), a chemotherapeutic drug, affects microtubule dynamics and influences endocytic trafficking. However, the mechanism and the dynamics of altered endocytic trafficking by paclitaxel treatment in single living cells still remain elusive. By labeling quantum dots (QDs) to the epidermal growth factor (EGF), we continuously tracked the endocytosis and post-endocytic trafficking of EGF receptors (EGFRs) in A549 cells for a long time interval. A single-cell analysis method was introduced to quantitatively study the dynamics of endocytic trafficking. Compared with the control cells, the velocity of directed motion was reduced by 30% due to the suppression of high speed movements of EGF-QDs along the microtubules in PTX-treated cells. The endocytic trafficking in PTX-treated cells was mainly via super-diffusive mode of motion, whereas in control cells, it was mostly via sub-diffusive mode of motion. Moreover, PTX shortened endosomal trafficking and prevented EGF-QDs from moving to the perinuclear area via the rapid delivery of EGF-QDs into the peripheral lysosomes. The present study may shed light on the mechanism of the effect of PTX on the treatment of lung cancer. PMID:23029028

Li, Hui; Duan, Zhao-Wen; Xie, Ping; Liu, Yu-Ru; Wang, Wei-Chi; Dou, Shuo-Xing; Wang, Peng-Ye

2012-01-01

369

Evaluation of vitamin B12 effects on DNA damage induced by paclitaxel.  

PubMed

Paclitaxel (PAC) is an anticancer drug that has been shown to generate free radicals leading to irreversible cell injury. Vitamin B12 has antioxidative properties and can protect DNA from free radicals. In this study, we examined the possible genotoxic effect of PAC on DNA as well as the possible protective effect of vitamin B12 on DNA damage induced by paclitaxel. Sister chromatid exchanges (SCEs), chromosomal aberrations (CAs) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels were measured in cultured human blood lymphocytes treated with PAC (10 µM) and/or vitamin B12 (2.7 mg/mL). Our results showed that PAC significantly increased the frequencies of SCEs (p < 0.001) and CAs (p < 0.001) in human blood lymphocytes, as compared to controls. These DNA damages, caused by PAC drug, were prevented by pretreatment of cells with vitamin B12. In addition, we showed that PAC induced an increase in 8-OHdG, a marker of oxidative DNA damage, and that this increase was prevented by vitamin B12. Vitamin B12 seems to protect against genotoxicity induced by PAC in human blood lymphocytes. PMID:24215581

Alzoubi, Karem; Khabour, Omar; Khader, Manal; Mhaidat, Nizar; Al-Azzam, Sayer

2014-07-01

370

Rapid and sensitive liquid chromatographic method for determination of Paclitaxel from parenteral formulation and nanoparticles.  

PubMed

A simple and fast reversed phase liquid chromatographic method was developed for estimation of paclitaxel in commercially available parenteral formulation and nanoparticles. Separations were carried out using mobile phase consisting of acetonitrile and 20 mM potassium dihydrogen phosphate (45:55, v/v) on Lichrocart(®) C(18) analytical column at a flow rate of 1 ml/min and detection wavelength of 230 nm. The developed method exhibited linearity over an analytical range of 50-2000 ng/ml with regression equation, mean peak area= 137.58 concentration (ng/ml)+1765.94, (R(2) =0.9999). The method demonstrated selectivity with no interfering peaks eluting near the vicinity of drug peak. The method was found to be sensitive with detection and quantification limits of 7.57 ng/ml and 22.94 ng/ml. The method has shown consistent and good recoveries from parenteral formulation (100.06±0.86%) and nanoparticles (100.43±0.91%). The method was successfully employed for the analysis of in vitro release study samples of nanoparticle formulation. The method was also applied for determination of paclitaxel content in various pharmaceutical formulations. PMID:21218057

Kollipara, S; Bende, G; Saha, R N

2010-07-01

371

Release modeling and comparison of nanoarchaeosomal, nanoliposomal and pegylated nanoliposomal carriers for paclitaxel.  

PubMed

Breast cancer is the most prevalent cancer among women. Recently, delivering by nanocarriers has resulted in a remarkable evolution in treatment of numerous cancers. Lipid nanocarriers are important ones while liposomes and archaeosomes are common lipid nanocarriers. In this work, paclitaxel was used and characterized in nanoliposomal and nanoarchaeosomal form to improve efficiency. To increase stability, efficiency and solubility, polyethylene glycol 2000 (PEG 2000) was added to some samples. MTT assay confirmed effectiveness of nanocarriers on MCF-7 cell line and size measuring validated nano-scale of particles. Nanoarchaeosomal carriers demonstrated highest encapsulation efficiency and lowest release rate. On the other hand, pegylated nanoliposomal carrier showed higher loading efficiency and less release compared with nanoliposomal carrier which verifies effect of PEG on improvement of stability and efficiency. Additionally, release pattern was modeled using artificial neural network (ANN) and genetic algorithm (GA). Using ANN modeling for release prediction, resulted in R values of 0.976, 0.989 and 0.999 for nanoliposomal, pegylated nanoliposomal and nanoarchaeosomal paclitaxel and GA modeling led to values of 0.954, 0.951 and 0.976, respectively. ANN modeling was more successful in predicting release compared with the GA strategy. PMID:24867099

Movahedi, Fatemeh; Ebrahimi Shahmabadi, Hasan; Alavi, Seyed Ebrahim; Koohi Moftakhari Esfahani, Maedeh

2014-09-01

372

LZTS1 downregulation confers paclitaxel resistance and is associated with worse prognosis in breast cancer  

PubMed Central

The Leucine Zipper Tumor Suppressor 1 (LZTS1) is a tumor suppressor gene, located at chromosome 8p22, which is frequently altered in human cancer. In normal tissue, its ubiquitous expression regulates cell mitosis by the stabilization of microtubule networks. LZTS1-deficient mouse embryonic fibroblasts have been shown to have an accelerated mitotic progression, and a higher resistance to taxanes, microtubule-stabilizing drugs. We investigate the role of Lzts1 in paclitaxel-resistance in breast cancer cells. Downregulation of Lzts1 expression significantly decreases sensitivity to paclitaxel in vitro. We further analyzed Lzts1 expression by immunohistochemistry in 270 primary breast cancer samples and 16 normal breast specimens. Lzts1 was significantly downregulated in breast cancer samples and its deregulation was associated with a higher incidence of tumor recurrence, and to a worse overall survival. Moreover, Lzts1-negative tumors were associated with unfavorable outcome after taxanes-based therapy. Thus our data suggest that Lzts1 deregulation is involved in breast cancer and its immunohistochemical evaluation may serve as a prognostic factor for breast cancer therapy PMID:24448468

Lovat, Francesca; Ishii, Hideshi; Schiappacassi, Monica; Fassan, Matteo; Barbareschi, Mattia; Galligioni, Enzo; Gasparini, Pierluigi; Baldassarre, Gustavo; Croce, Carlo M.; Vecchione, Andrea

2014-01-01

373

Facile preparation of paclitaxel loaded silk fibroin nanoparticles for enhanced antitumor efficacy by locoregional drug delivery.  

PubMed

Non-toxic, safe materials and preparation methods are among the most important factors when designing nanoparticles (NPs) for future clinical application. Here we report a novel and facile method encapsulating anticancer drug paclitaxel (PTX) into silk fibroin (SF), a biocompatible and biodegradable natural polymer, without adding any toxic organic solvents, surfactants or other toxic agents. The paclitaxel loaded silk fibroin nanoparticles (PTX-SF-NPs) with a diameter of 130 nm were formed in an aqueous solution at room temperature by self-assembling of SF protein, which demonstrated mainly silk I conformation in the NPs. In cellular uptake experiments, coumarin-6 loaded SF NPs were taken up efficiently by two human gastric cancer cell lines BGC-823 and SGC-7901. In vitro cytotoxicity studies demonstrated that PTX kept its pharmacological activity when incorporating into PTX-SF-NPs, while SF showed no cytotoxicity to cells. The in vivo antitumor effects of PTX-SF-NPs were evaluated on gastric cancer nude mice exnograft model. We found that locoregional delivery of PTX-SF-NPs demonstrated superior antitumor efficacy by delaying tumor growth and reducing tumor weights compared with systemic administration. Furthermore, the organs of mice in NP treated groups didn't show obvious toxicity, indicating the in vivo safety of SF NPs. These results suggest that SF NPs are promising drug delivery carriers, and locoregional delivery of SF NPs could be a potential future clinical cancer treatment regimen. PMID:24274601

Wu, Puyuan; Liu, Qin; Li, Rutian; Wang, Jing; Zhen, Xu; Yue, Guofeng; Wang, Huiyu; Cui, Fangbo; Wu, Fenglei; Yang, Mi; Qian, Xiaoping; Yu, Lixia; Jiang, Xiqun; Liu, Baorui

2013-12-11

374

MCAK and Paclitaxel Have Differential Effects on Spindle Microtubule Organization and Dynamics  

PubMed Central

Within the mitotic spindle, there are multiple populations of microtubules with different turnover dynamics, but how these different dynamics are maintained is not fully understood. MCAK is a member of the kinesin-13 family of microtubule-destabilizing enzymes that is required for proper establishment and maintenance of the spindle. Using quantitative immunofluorescence and fluorescence recovery after photobleaching, we compared the differences in spindle organization caused by global suppression of microtubule dynamics, by treating cells with low levels of paclitaxel, versus specific perturbation of spindle microtubule subsets by MCAK inhibition. Paclitaxel treatment caused a disruption in spindle microtubule organization marked by a significant increase in microtubules near the poles and a reduction in K-fiber fluorescence intensity. This was correlated with a faster t1/2 of both spindle and K-fiber microtubules. In contrast, MCAK inhibition caused a dramatic reorganization of spindle microtubules with a significant increase in astral microtubules and reduction in K-fiber fluorescence intensity, which correlated with a slower t1/2 of K-fibers but no change in the t1/2 of spindle microtubules. Our data support the model that MCAK perturbs spindle organization by acting preferentially on a subset of microtubules, and they support the overall hypothesis that microtubule dynamics is differentially regulated in the spindle. PMID:19158381

Rizk, Rania S.; Bohannon, Kevin P.; Wetzel, Laura A.; Powers, James; Shaw, Sidney L.

2009-01-01

375

The enthalpies and kinetic of dissolution of diterpenoid derivative—paclitaxel in aqueous NaCl solutions at 309.5 K  

NASA Astrophysics Data System (ADS)

The enthalpies of dissolution of paclitaxel in normal saline were measured using a RD496-2000 Calvet Microcalorimeter at 309.65 K under atmospheric pressure. The differential enthalpy (?dif H m ) and molar enthalpy (?sol H m) of dissolution of paclitaxel innormal saline were determined. The corresponding kinetic equation described the dissolution process was elucidated to be d?/ dt = 10-3.57(1 - a)1.15. Moreover, the half-life, ?sol H m , ?sol G m and ?sol S m of the dissolution process were also obtained. This work will provide a potential reference for the clinical application of paclitaxel.

Chen, Qi; Zhao, Weiwei; Pu, Xiaohua

2013-08-01

376

Prostate Cancer Prostatic Dis . Author manuscript Pilot trial of adjuvant paclitaxel plus androgen deprivation for patients with  

E-print Network

Prostate Cancer Prostatic Dis . Author manuscript Page /1 7 Pilot trial of adjuvant paclitaxel plus androgen deprivation for patients with high-risk prostate cancer after radical prostatectomy: results unclear with no clear consensus for men with high-risk prostate cancer after radical prostatectomy. We

Boyer, Edmond

377

Tumor therapy with a urokinase plasminogen activator-activated anthrax lethal toxin alone and in combination with paclitaxel.  

PubMed

PA-U2, an engineered anthrax protective antigen that is activated by urokinase was combined with wildtype lethal factor in the treatment of Colo205 colon adenocarcinoma in vitro and B16-BL6 mouse melanoma in vitro and in vivo. This therapy was also tested in combination with the small molecule paclitaxel, based on prior reports suggesting synergy between ERK1/2 inhibition and chemotherapeutics. Colo205 was sensitive to PA-U2/LF while B16-BL6 was not. For the combination treatment of B16-BL6, paclitaxel showed a dose response in vitro, but cells remained resistant to PA-U2/LF even in the presence of paclitaxel. In vivo, each therapy slowed tumor progression, and an additive effect between the two was observed. Since LF targets tumor vasculature while paclitaxel is an antimitotic, it is possible the agents were acting against different cells in the stroma, precluding a synergistic effect. The engineered anthrax toxin PA-U2/LF warrants further development and testing, possibly in combination with an antiangiogenesis therapy such as sunitinib or sorafinib. PMID:22843210

Wein, Alexander N; Liu, Shihui; Zhang, Yi; McKenzie, Andrew T; Leppla, Stephen H

2013-02-01

378

Stability of parenteral nanoemulsions loaded with paclitaxel: the influence of lipid phase composition, drug concentration and storage temperature.  

PubMed

Paclitaxel was loaded into licensed parenteral nutrition nanoemulsions (Clinoleic® and Intralipid®) using bath sonication, and the stability of the formulations was investigated following storage for two weeks at room temperature or at 4?°C. In general, Clinoleic droplets were smaller than Intralipid droplets, being around 255 and 285?nm, respectively, for blank and freshly loaded emulsions. Regardless of storage temperature, the Clinoleic exhibited a very slight or no increase in droplet size upon storage, whilst the droplet size of the Intralipid emulsion increased significantly. The droplet size of both emulsions was minimally affected by paclitaxel concentration within the range of 0, 1, 3 and 6?mg/ml. The pH of both emulsions markedly decreased upon storage at room temperature, which was possibly attributed to the production of fatty acids resulting from phospholipid hydrolysis. However, at 4?°C, the pH of Clinoleic emulsion was unaffected by storage or paclitaxel concentration while the Intralipid emulsion demonstrated a trend for pH reduction. Both nanoemulsions had a negative zeta potential, with the Clinoleic formulations having the highest charge, possibly explaining the better size stability of this emulsion. Overall, this study has shown that paclitaxel was successfully loaded into clinically licensed parenteral emulsions and that Clinoleic showed greater stability than the Intralipid. PMID:24093888

Kadam, Alisha N; Najlah, Mohammad; Wan, Ka-Wai; Ahmed, Waqar; Crean, St John; Phoenix, David A; Taylor, Kevin M G; Elhissi, Abdelbary M A

2014-12-01

379

Materials Science and Engineering A 438440 (2006) 11191123 Surface characteristics and biological properties of paclitaxel-embedding  

E-print Network

spectroscopy (XPS), high performance of liquid chromatography (HPLC) and platelet adhesion test. AFM results be eliminated from body as carbon dioxide and water, and PLGA has been increasingly used to delivery drugs [6 paper, paclitaxel-embedding PLGA coatings with a variable dosage were prepared. The surface

Zheng, Yufeng

380

Paclitaxel-loaded nanoparticles of star-shaped cholic acid-core PLA-TPGS copolymer for breast cancer treatment  

PubMed Central

A system of novel nanoparticles of star-shaped cholic acid-core polylactide-d-?-tocopheryl polyethylene glycol 1000 succinate (CA-PLA-TPGS) block copolymer was developed for paclitaxel delivery for breast cancer treatment, which demonstrated superior in vitro and in vivo performance in comparison with paclitaxel-loaded poly(d,l-lactide-co-glycolide) (PLGA) nanoparticles and linear PLA-TPGS nanoparticles. The paclitaxel- or couramin 6-loaded nanoparticles were fabricated by a modified nanoprecipitation method and then characterized in terms of size, surface charge, surface morphology, drug encapsulation efficiency, and in vitro drug release. The CA-PLA-TPGS nanoparticles were found to be spherical in shape with an average size of around 120 nm. The nanoparticles were found to be stable, showing no change in the particle size and surface charge during 90-day storage of the aqueous solution. The release profiles of the paclitaxel-loaded nanoparticles exhibited typically biphasic release patterns. The results also showed that the CA-PLA-TPGS nanoparticles have higher antitumor efficacy than the PLA-TPGS nanoparticles and PLGA nanoparticles in vitro and in vivo. In conclusion, such nanoparticles of star-shaped cholic acid-core PLA-TPGS block copolymer could be considered as a potentially promising and effective strategy for breast cancer treatment. PMID:24134303

2013-01-01

381

Novel C-seco-taxoids possessing high potency against paclitaxel-resistant cancer cell lines overexpressing class III ?-tubulin  

PubMed Central

Novel C-seco-taxoids were synthesized from 10-deacetylbaccatin III and their potencies evaluated against drug-sensitive and drug-resistant cancer cell lines. The drug-resistant cell lines include ovarian cancer cell lines resistant to cisplatin, topotecan, adriamycin and paclitaxel overexpressing class III ?-tubulin, A2780TC1 and A2780TC3. The last two cell lines were selected through chronic exposure of A2780wt to paclitaxel and Pgp blocker cyclosporine. All novel C-seco-taxoids exhibited remarkable potency against A2780TC1 and A2780TC3 cell lines, and no cross resistance to cisplatin- and topotecan-resistant cell lines, A2780CIS and A2780TOP. Four of those C-seco-taxoids exhibit much higher activities than IDN5390 against paclitaxel-resistant cell lines, A2780ADR, A2780TC1 and A2780TC3. SB-CST-10202 possesses the best all-round high potencies across different drug-resistant cell lines. Molecular modeling studies, including molecular dynamics simulations, on the drug-protein complexes of class I and III ?-tubulins were performed to identify possible cause of the remarkable potency of these C-seco-taxoids against paclitaxel-resistant cell lines overexpressing class III ?-tubulin. PMID:19423340

Pepe, Antonella; Sun, Liang; Zanardi, Ilaria; Wu, Xinyuan; Ferlini, Cristiano; Fontana, Gabriele; Bombardelli, Ezio; Ojima, Iwao

2009-01-01

382

Shape-controlled Paclitaxel nanoparticles with multiple morphologies: rod-shaped, worm-like, spherical, and fingerprint-like.  

PubMed

Although many nanocarriers have been developed to encapsulate paclitaxel (PTX), the drug loading and circulation time in vivo always are not ideal because of its rigid "brickdust" molecular structure. People usually concentrate their attention on the spherical nanocarriers, here paclitaxel nanoparticles with different geometries were established through the chemical modification of PTX, nanoprecipitation, and core-matched cargos. Previously we have developed rod-shape paclitaxel nanocrystals using block copolymer, pluronic F127. Unfortunately, the pharmacokinetic (PK) profile of PTX nanocrystals is very poor. However, when PTX was replaced by its prodrug, the geometry of the nanoparticles changed from rod-shaped to worm-like. The worm-like nanoparticles can be further changed to spherical nanoparticles using the nanoprecipitation method, and changed to fingerprint-like nanoparticles upon the addition of the core-matched PTX. The nanoparticles with nonspherical morphologies, including worm-like nanoparticles and fingerprint-like nanoparticles, offer significant advantages in regards to key PK parameters in vivo. More important, in this report the application of the core-matching technology in creating a core-matched environment capable of controlling the in vivo PK of paclitaxel was demonstrated, and it revealed a novel technique platform to construct nanoparticles and improve the poor PK profiles of the drugs. PMID:25188586

Wang, Yongjun; Wang, Dun; Fu, Qiang; Liu, Dan; Ma, Yan; Racette, Kelly; He, Zhonggui; Liu, Feng

2014-10-01

383

Bisphosphonates inhibit stellate cell activity and enhance antitumor effects of nanoparticle albumin-bound Paclitaxel in pancreatic ductal adenocarcinoma.  

PubMed

Pancreatic stellate cells (PSC) have been recognized as the principal cells responsible for the production of fibrosis in pancreatic ductal adenocarcinoma (PDAC). Recently, PSCs have been noted to share characteristics with cells of monocyte-macrophage lineage (MML cells). Thus, we tested whether PSCs could be targeted with the nitrogen-containing bisphosphonates (NBP; pamidronate or zoledronic acid), which are potent MML cell inhibitors. In addition, we tested NBPs treatment combination with nanoparticle albumin-bound paclitaxel (nab-paclitaxel) to enhance antitumor activity. In vitro, we observed that PSCs possess ?-naphthyl butyrate esterase (ANBE) enzyme activity, a specific marker of MML cells. Moreover, NBPs inhibited PSCs proliferation, activation, release of macrophage chemoattractant protein-1 (MCP-1), and type I collagen expression. NBPs also induced PSCs apoptosis and cell-cycle arrest in the G1 phase. In vivo, NBPs inactivated PSCs; reduced fibrosis; inhibited tumor volume, tumor weight, peritoneal dissemination, angiogenesis, and cell proliferation; and increased apoptosis in an orthotopic murine model of PDAC. These in vivo antitumor effects were enhanced when NBPs were combined with nab-paclitaxel but not gemcitabine. Our study suggests that targeting PSCs and tumor cells with NBPs in combination with nab-paclitaxel may be a novel therapeutic approach to PDAC. Mol Cancer Ther; 13(11); 2583-94. ©2014 AACR. PMID:25193509

Gonzalez-Villasana, Vianey; Rodriguez-Aguayo, Cristian; Arumugam, Thiruvengadam; Cruz-Monserrate, Zobeida; Fuentes-Mattei, Enrique; Deng, Defeng; Hwang, Rosa F; Wang, Huamin; Ivan, Cristina; Garza, Raul Joshua; Cohen, Evan; Gao, Hui; Armaiz-Pena, Guillermo N; Del C Monroig-Bosque, Paloma; Philip, Bincy; Rashed, Mohammed H; Aslan, Burcu; Erdogan, Mumin Alper; Gutierrez-Puente, Yolanda; Ozpolat, Bulent; Reuben, James M; Sood, Anil K; Logsdon, Craig; Lopez-Berestein, Gabriel

2014-11-01

384

Molecular determinants of response to matuzumab in combination with paclitaxel for patients with advanced non-small cell lung cancer  

Microsoft Academic Search

Antibodies targeting epidermal growth factor receptor (EGFR) have proven to be effective in patients with non- small cell lung cancer (NSCLC) that express EGFR. We re- cently published a phase I study of weekly matuzumab plus paclitaxel. This therapy was well tolerated and showed clinical responses in the majority of patients. Although matu- zumab displays potent antitumor activity in some

Marcus M. Schittenhelm; Christian Kollmannsberger; Karin Oechsle; Amy Harlow; Jason Morich; Friedemann Honecker; Raffael Kurek; Stephan Storkel; Lothar Kanz; Christopher L. Corless; Kwok-Kin Wong; Carsten Bokemeyer; Michael C. Heinrich

2009-01-01

385

Paclitaxel-loaded nanoparticles of star-shaped cholic acid-core PLA-TPGS copolymer for breast cancer treatment  

NASA Astrophysics Data System (ADS)

A system of novel nanoparticles of star-shaped cholic acid-core polylactide- d-?-tocopheryl polyethylene glycol 1000 succinate (CA-PLA-TPGS) block copolymer was developed for paclitaxel delivery for breast cancer treatment, which demonstrated superior in vitro and in vivo performance in comparison with paclitaxel-loaded poly( d, l-lactide- co-glycolide) (PLGA) nanoparticles and linear PLA-TPGS nanoparticles. The paclitaxel- or couramin 6-loaded nanoparticles were fabricated by a modified nanoprecipitation method and then characterized in terms of size, surface charge, surface morphology, drug encapsulation efficiency, and in vitro drug release. The CA-PLA-TPGS nanoparticles were found to be spherical in shape with an average size of around 120 nm. The nanoparticles were found to be stable, showing no change in the particle size and surface charge during 90-day storage of the aqueous solution. The release profiles of the paclitaxel-loaded nanoparticles exhibited typically biphasic release patterns. The results also showed that the CA-PLA-TPGS nanoparticles have higher antitumor efficacy than the PLA-TPGS nanoparticles and PLGA nanoparticles in vitro and in vivo. In conclusion, such nanoparticles of star-shaped cholic acid-core PLA-TPGS block copolymer could be considered as a potentially promising and effective strategy for breast cancer treatment.

Tang, Xiaolong; Cai, Shuyu; Zhang, Rongbo; Liu, Peng; Chen, Hongbo; Zheng, Yi; Sun, Leilei

2013-10-01

386

PLGA\\/TPGS Nanoparticles for Controlled Release of Paclitaxel: Effects of the Emulsifier and Drug Loading Ratio  

Microsoft Academic Search

Purpose. We successfully manufactured nanoparticles of biodegradable polymers for controlled release of paclitaxel. TPGS (d-a-tocopheryl polyethylene glycol 1000 succinate) could be a novel material to make nanoparticles of high drug encapsulation efficiency (EE) and desired physicochemical and pharmaceutical properties of the drug loaded nanoparticles. Among various controlling parameters in the process, the present work is to elucidate the effects of

Li Mu; Si-Shen Feng

2003-01-01

387

Weekly paclitaxel plus trastuzumab in metastatic breast cancer pretreated with anthracyclines-a phase II multipractice study  

PubMed Central

Background The 3-weekly combination of trastuzumab and paclitaxel has been approved for the treatment of advanced breast cancer based on a large pivotal study. However, mono and combination chemotherapy trials suggest that weekly paclitaxel has a better therapeutic index, especially in the palliative setting. The present trial examined the efficacy and safety of weekly paclitaxel over a limited duration combined with continued trastuzumab in HER2+ patients. Methods Patients with histologically confirmed metastatic breast cancer overexpressing HER2 were eligible if pretreated with anthracycline in either the adjuvant or palliative setting. Treatment consisted of weekly trastuzumab (2 mg/kg/week for up to one year after a loading dose of 4 mg/kg in week 1) and paclitaxel (90 mg/m², administered in weeks 1–6 and 8–13). Results Twenty-seven German centers enrolled 121 patients. The median number of metastatic sites was two (range 1–5); 38% of patients had received chemotherapy for advanced disease. After a median 42 weeks of trastuzumab treatment, limited by disease progression in roughly half the patients, a best objective response rate (complete response?+?partial response) of 76% was achieved, including complete remissions in 29%. 74% of patients lived without tumor progression at six months. Median progression-free and overall survival were 9.4 (95% confidence interval [CI]: 8.1–11.3) and 22 months (95% CI: 17–46). After alopecia, Common Toxicity Criteria grade ?2 toxicity was predominantly hematological (leukopenia [31%] and anemia [41%]); however, thrombocytopenia occurred in only 5%. Neurotoxicity was remarkably low. Two cardiac events (grades 2 and 3) were presumed treatment-related. Conclusions Weekly paclitaxel plus trastuzumab allows an increased dose density and offers an attractive and effective alternative to the conventional schedule. Limiting the duration of cytotoxic therapy to 3 months seems to be an option to reduce neurotoxicity without impairing long-term outcome. PMID:22559145

2012-01-01

388

A Phase I study of capecitabine, carboplatin, and paclitaxel with external beam radiation therapy for esophageal carcinoma  

SciTech Connect

Purpose: Concurrent chemotherapy and radiation therapy (RT) are used to treat patients with esophageal cancer. The optimal combination of chemotherapeutic agents with RT is undefined. We evaluated a combination of capecitabine, carboplatin, and paclitaxel with RT in a phase I study. Methods and Materials: Patients with squamous cell carcinoma or adenocarcinoma of the esophagus initially received capecitabine, carboplatin, and paclitaxel with RT (1.8 Gy daily to 50.4 Gy). After completion, patients were restaged and evaluated for surgery. Primary endpoints included determination of dose-limiting toxicities (DLT) and a recommended phase II dose, non-DLT, and preliminary radiographic and pathologic response rates. Results: Thirteen patients were enrolled (10 men, 3 women). All were evaluable for toxicity and efficacy. Two of 3 patients at dose level 1 (capecitabine 825 mg/m{sup 2} twice daily on RT days, carboplatin area under the curve (AUC) 2 weekly, paclitaxel 60 mg/m{sup 2} weekly) had DLT (both Grade 4 esophagitis). Of these 3, 2 underwent esophagectomy and had pathologic complete response (pCR). Ten patients were then enrolled at dose level -1 (capecitabine 600 mg/m{sup 2} twice daily, carboplatin AUC 1.5, paclitaxel 45 mg/m{sup 2}). Overall, 3 of 10 patients at dose level -1 developed DLT (2 Grade 3 esophagitis, 1 Grade 3 hypotension). Esophagectomy was performed in 6 of 10 patients. All patients had pathologic downstaging and 2 of 6 had pCR. Conclusions: The maximally tolerated/recommended phase II doses were capecitabine 600 mg/m{sup 2} twice daily, carboplatin AUC 1.5 weekly, and paclitaxel 45 mg/m{sup 2} weekly with RT to 50.4 Gy. In our small study, this regimen appears active but is accompanied by significant toxicities, primarily esophagitis.

Czito, Brian G. [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States)]. E-mail: czito@radonc.duke.edu; Kelsey, Chris R. [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Hurwitz, Herbert I. [Department of Internal Medicine, Division of Medical Oncology and Transplantation, Duke University Medical Center, Durham, NC (United States); Willett, Chris G. [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Morse, Michael A. [Department of Internal Medicine, Division of Medical Oncology and Transplantation, Duke University Medical Center, Durham, NC (United States); Blobe, Gerard C. [Department of Internal Medicine, Division of Medical Oncology and Transplantation, Duke University Medical Center, Durham, NC (United States); Fernando, Nishan H. [Department of Internal Medicine, Division of Medical Oncology and Transplantation, Duke University Medical Center, Durham, NC (United States); D'Amico, Thomas A. [Department of General Surgery, Duke University Medical Center, Durham, NC (United States); Harpole, David H. [Department of General Surgery, Duke University Medical Center, Durham, NC (United States); Honeycutt, Wanda R.N. [Department of Internal Medicine, Division of Medical Oncology and Transplantation, Duke University Medical Center, Durham, NC (United States); Yu Daohai [Department of Biostatistics and Bioinformatics, Duke University Medical Center, Durham, NC (United States); Bendell, Johanna C. [Department of Internal Medicine, Division of Medical Oncology and Transplantation, Duke University Medical Center, Durham, NC (United States)

2007-03-15

389

A comparative study of the cytoskeleton binding drugs nocodazole and taxol with a mammalian cell quartz crystal microbalance biosensor: different dynamic responses and energy dissipation effects.  

PubMed

The quartz crystal microbalance (QCM) was used to create piezoelectric whole-cell biosensors utilizing either living endothelial cells (ECs) or the metastatic human mammary cancer cell line MDA-MB-231 adhering to the gold QCM surface under in vitro growth conditions. We utilized the whole-cell QCM biosensors for the detection of the effects of varying concentrations of the microtubule binding drugs taxol and nocodazole by measuring changes in the QCM steady state frequency (Deltaf) and motional resistance (DeltaR), shift values. Using 0.11-50 microM nocodazole, we observed the Deltaf shift values of the biosensors, consisting of 20,000 ECs, to decrease significantly in magnitude (nearly 100%) to a limiting value, in a dose-dependent fashion, over a 5- to 6-h incubation period following drug addition. This effect is consistent with nocodazole's known disruption of intracellular microtubules. On the other hand, 10 microM taxol caused little alteration in Deltaf over the same time period, consistent with its microtubule hyperstabilization effect. When the EC QCM biosensor Deltaf shift values were normalized by the number of ECs found firmly attached to the QCM surface via trypsin removal and electronic counting, the dose curve was shifted to lower nocodazole concentrations, resulting in a more sensitive drug biosensor. The kinetics of the Deltaf decrease with increasing nocodazole concentrations measured by the EC QCM biosensor was found to be similar at all drug concentrations and was well fit by a single first-order exponential decay equation. For all nocodazole doses, t(0.5) was invariant, averaging t(0.5)=0.83+/-0.14 h. These data demonstrate that a single dynamic sensing system within the cell, the microtubules, is disrupted by the addition of nocodazole and this process is sensed by the cell QCM biosensor. This interpretation of the data was confirmed by a fluorescence light microscopy investigation of ECs undergoing treatment with increasing nocodazole doses using a fluorescent antibody to alpha-tubulin. These studies revealed a corresponding loss of the spread morphology of the cells, concomitant with a rearrangement of the extended native microtubules into increasingly large aggregates with the cells eventually lifting from the surface in significant numbers at 50 microM. At 6 microM nocodazole, partial reversibility of the EC QCM biosensor was demonstrated. These results indicate that the EC QCM biosensor can be used to detect and study EC cytoskeleton alterations and dynamics. We suggest the potential of this cellular biosensor for the real-time identification or screening of all classes of biologically active drugs or biological macromolecules that affect cellular attachment and cellular spreading, regardless of their molecular mechanism of action. PMID:17161375

Marx, Kenneth A; Zhou, Tiean; Montrone, Anne; McIntosh, Donna; Braunhut, Susan J

2007-02-01

390

Colchitaxel, a coupled compound made from microtubule inhibitors colchicine and paclitaxel  

PubMed Central

Background Tumor promoters enhance tumor yield in experimental animals without directly affecting the DNA of the cell. Promoters may play a role in the development of cancer, as humans are exposed to them in the environment. In work based on computer-assisted microscopy and sophisticated classification methods, we showed that cells could be classified by reference to a database of known normal and cancerous cell phenotypes. Promoters caused loss of properties specific to normal cells and gain of properties of cancer cells. Other compounds, including colchicine, had a similar effect. Colchicine given together with paclitaxel, however, caused cells to adopt properties of normal cells. This provided a rationale for tests of microtubule inhibitor combinations in cancer patients. The combination of a depolymerizing and a stabilizing agent is a superior anti-tumor treatment. The biological basis of the effect is not understood. Results A single compound containing both colchicine and paclitaxel structures was synthesized. Colchicine is an alkaloid with a trimethoxyphenyl ring (ring A), a ring with an acetamide linkage (ring B), and a tropolone ring (ring C). Although rings A and C are important for tubulin-binding activity, the acetamide linkage on ring B could be replaced by an amide containing a glutamate linker. Alteration of the C-7 site on paclitaxel similarly had little or no inhibitory effect on its biological activity. The linker was attached to this position. The coupled compound, colchitaxel (1), had some of the same effects on microtubules as the combination of starting compounds. It also caused shortening and fragmentation of the + end protein cap. Conclusion Since microtubule inhibitor combinations give results unlike those obtained with either inhibitor alone, it is important to determine how such combinations affect cell shape and growth. Colchitaxel shows a subset of the effects of the inhibitor combination. Thus, it may be able to bind the relevant cellular target of the combination. It will be useful to determine the basis of the shape reversal effect and possibly, the reasons for therapeutic efficacy of microtubule inhibitor combinations. PMID:16813651

Bombuwala, Karunananda; Kinstle, Thomas; Popik, Vladimir; Uppal, Sonal O; Olesen, James B; Vina, Jose; Heckman, Carol A

2006-01-01

391

An antimitotic and antivascular agent BPR0L075 overcomes multidrug resistance and induces mitotic catastrophe in paclitaxel-resistant ovarian cancer cells.  

PubMed

Paclitaxel plays a major role in the treatment of ovarian cancer; however, resistance to paclitaxel is frequently observed. Thus, new therapy that can overcome paclitaxel resistance will be of significant clinical importance. We evaluated antiproliferative effects of an antimitotic and antivascular agent BPR0L075 in paclitaxel-resistant ovarian cancer cells. BPR0L075 displays potent and broad-spectrum cytotoxicity at low nanomolar concentrations (IC50?=?2-7 nM) against both parental ovarian cancer cells (OVCAR-3, SKOV-3, and A2780-1A9) and paclitaxel-resistant sublines (OVCAR-3-TR, SKOV-3-TR, 1A9-PTX10), regardless of the expression levels of the multidrug resistance transporter P-gp and class III ?-tubulin or mutation of ?-tubulin. BPR0L075 blocks cell cycle at the G2/M phase in paclitaxel-resistant cells while equal concentration of paclitaxel treatment was ineffective. BPR0L075 induces cell death by a dual mechanism in parental and paclitaxel-resistant ovarian cancer cells. In the parental cells (OVCAR-3 and SKOV-3), BPR0L075 induced apoptosis, evidenced by poly(ADP-ribose) polymerase (PARP) cleavage and DNA ladder formation. BPR0L075 induced cell death in paclitaxel-resistant ovarian cancer cells (OVCAR-3-TR and SKOV-3-TR) is primarily due to mitotic catastrophe, evidenced by formation of giant, multinucleated cells and absence of PARP cleavage. Immunoblotting analysis shows that BPR0L075 treatment induced up-regulation of cyclin B1, BubR1, MPM-2, and survivin protein levels and Bcl-XL phosphorylation in parental cells; however, in resistant cells, the endogenous expressions of BubR1 and survivin were depleted, BPR0L075 treatment failed to induce MPM-2 expression and phosphorylation of Bcl-XL. BPR0L075 induced cell death in both parental and paclitaxel-resistant ovarian cancer cells proceed through caspase-3 independent mechanisms. In conclusion, BPR0L075 displays potent cytotoxic effects in ovarian cancer cells with a potential to overcome paclitaxel resistance by bypassing efflux transporters and inducing mitotic catastrophe. BPR0L075 represents a novel microtubule therapeutic to overcome multidrug resistance and trigger alternative cell death by mitotic catastrophe in ovarian cancer cells that are apoptosis-resistant. PMID:23762410

Wang, Xiaolei; Wu, Erxi; Wu, Jun; Wang, Tian-Li; Hsieh, Hsing-Pang; Liu, Xinli

2013-01-01

392

An Antimitotic and Antivascular Agent BPR0L075 Overcomes Multidrug Resistance and Induces Mitotic Catastrophe in Paclitaxel-Resistant Ovarian Cancer Cells  

PubMed Central

Paclitaxel plays a major role in the treatment of ovarian cancer; however, resistance to paclitaxel is frequently observed. Thus, new therapy that can overcome paclitaxel resistance will be of significant clinical importance. We evaluated antiproliferative effects of an antimitotic and antivascular agent BPR0L075 in paclitaxel-resistant ovarian cancer cells. BPR0L075 displays potent and broad-spectrum cytotoxicity at low nanomolar concentrations (IC50?=?2–7 nM) against both parental ovarian cancer cells (OVCAR-3, SKOV-3, and A2780-1A9) and paclitaxel-resistant sublines (OVCAR-3-TR, SKOV-3-TR, 1A9-PTX10), regardless of the expression levels of the multidrug resist