Docetaxel In Mice Research Articles

Application of Ganoderma lucidum extract for constructing an oral docetaxel delivery system

Docetaxel is one of the most valuable chemotherapeutic drugs, but it has extremely low oral bioavailability. In this study, an oral docetaxel delivery system was constructed based on the extract of Ganoderma lucidum, a well-known medicinal mushroom. First, a G. lucidum extract-docetaxel complex was prepared by stirring and freeze-drying. Results demonstrated that, compared to the docetaxel group, the exposure levels of docetaxel in the complex group were significantly increased in the mouse portal vein (Cmax, 599.7 vs. 58.5 ng/mL; AUC0–12 h, 631.2 vs. 185.9 ng·h/mL), systemic circulation (Cmax, 310.4 vs. 34.9 ng/mL; AUC0–12 h, 467.6 vs. 124.7 ng·h/mL), liver (Cmax, 431.2 vs. 58.4 ng/g liver; AUC0–12 h, 2007.3 vs. 473.0 ng·h/g liver), and lungs (Cmax, 1711.3 vs. 362.7 ng/g lung; AUC0–12 h, 5188.5 vs. 1329.5 ng·h/g lung). Moreover, in the complex group, except for metabolic stability (p > 0.05), transportation from the mucosal side of gut sacs to the serosal side (p < 0.01), solubility (52.6 vs. 4.2 μg/mL), and release of docetaxel in water were significantly improved (15 min, 5.5% vs. 2.3%; 8 h, 35.0% vs. 15.1%). Furthermore, scanning electron microscope (SEM), differential scanning calorimetry (DSC), and powder X-ray diffraction (PXRD) analysis demonstrated the amorphous existing form of docetaxel. In conclusion, the pharmacokinetics of oral docetaxel in mice was improved by the G. lucidum extract-docetaxel complex, which changed the existing form of docetaxel from crystalline to amorphous. This study provides a simple solution to docetaxel’s low oral bioavailability.

Polysaccharide of Ganoderma lucidum Ameliorates Cachectic Myopathy Induced by the Combination Cisplatin plus Docetaxel in Mice.

Cachexia is a lethal muscle-wasting syndrome associated with cancer and chemotherapy use. Mounting evidence suggests a correlation between cachexia and intestinal microbiota, but there is presently no effective treatment for cachexia. Whether the Ganoderma lucidum polysaccharide Liz-H exerts protective effects on cachexia and gut microbiota dysbiosis induced by the combination cisplatin plus docetaxel (cisplatin + docetaxel) was investigated. C57BL/6J mice were intraperitoneally injected with cisplatin + docetaxel, with or without oral administration of Liz-H. Body weight, food consumption, complete blood count, blood biochemistry, and muscle atrophy were measured. Next-generation sequencing was also performed to investigate changes to gut microbial ecology. Liz-H administration alleviated the cisplatin + docetaxel-induced weight loss, muscle atrophy, and neutropenia. Furthermore, upregulation of muscle protein degradation-related genes (MuRF-1 and Atrogin-1) and decline of myogenic factors (MyoD and myogenin) after treatment of cisplatin and docetaxel were prevented by Liz-H. Cisplatin and docetaxel treatment resulted in reducing comparative abundances of Ruminococcaceae and Bacteroides, but Liz-H treatment restored these to normal levels. This study indicates that Liz-H is a good chemoprotective reagent for cisplatin + docetaxel-induced cachexia. IMPORTANCE Cachexia is a multifactorial syndrome driven by metabolic dysregulation, anorexia, systemic inflammation, and insulin resistance. Approximately 80% of patients with advanced cancer have cachexia, and cachexia is the cause of death in 30% of cancer patients. Nutritional supplementation has not been shown to reverse cachexia progression. Thus, developing strategies to prevent and/or reverse cachexia is urgent. Polysaccharide is a major biologically active compound in the fungus Ganoderma lucidum. This study is the first to report that G. lucidum polysaccharides could alleviate chemotherapy-induced cachexia via reducing expression of genes that are known to drive muscle wasting, such as MuRF-1 and Atrogin-1. These results suggest that Liz-H is an effective treatment for cisplatin + docetaxel-induced cachexia.

PAUF as a Target for Treatment of High PAUF-Expressing Ovarian Cancer.

Pancreatic adenocarcinoma up-regulated factor (PAUF) plays an important role in tumor growth, metastasis, and immune evasion in the pancreatic tumor microenvironment, and recent studies suggest an association between PAUF expression and poor prognosis in ovarian cancer patients. The current study aimed 1) to characterize the potential tumor-promoting role of PAUF in ovarian cancer, using in vitro and in vivo models, including a PAUF-knockout OVCAR-5 cell line, and 2) to explore the potential therapeutic effects of an anti-PAUF antibody for ovarian cancer. Recombinant PAUF significantly increased tumor metastatic capacity (migration, invasion, and adhesion) in all the ovarian cancer cell lines tested, except for the OVCAR-5 cell line which expresses PAUF at a much higher level than the other cells. PAUF-knockout in the OVCAR-5 cell line led to apparently delayed tumor growth in vitro and in vivo. Furthermore, the administration of an anti-PAUF antibody exhibited notable sensitizing and synchronizing effects on docetaxel in mice bearing the OVCAR-5 xenograft tumors. Taken together, this study shows that the expression level of PAUF is an independent factor determining malignant behaviors of ovarian cancer and, for the first time, it suggests that PAUF may be a promising therapeutic target for high PAUF-expressing ovarian cancer.

PEGylated solid lipid nanoparticles functionalized by aptamer for targeted delivery of docetaxel in mice bearing C26 tumor

Objective: Colorectal cancer is one of the most deadly cancers in the world. Docetaxel (DTX) is a potentially important chemotherapeutic agent for the treatment of cancer. Many studies have attempted to improve its bioavailability and efficiency using different nanoparticulate drug delivery systems. Significance: In current study, PEGylated solid lipid nanoparticles (SLNs) containing DTX were prepared and modified with AS1411 anti-nucleolin aptamers to target nucleoin receptors on colorectal cancer cells. Methods: Nanoparticles were characterized and the morphology was evaluated. In vitro studies were investigated on murine colon carcinoma (C26) and Chinese hamster ovary (CHO) cell lines. Then in vivo antitumor efficacy and survival analysis were evaluated in mice bearing C26 tumor model. Results: Results showed 135-140 nm particle size and about 78% DTX entrapment efficiency for active targeted samples. PEGylated and aptamer-targeted SLNs containing DTX had the lowest IC50 (0.28 and 0.11 nM for 3 and 6 hours incubation respectively) and higher cellular uptake values in C26 cell line. Also in vivo results demonstrated that PEGylated and aptamer-targeted SLNs containing Docetaxel (Apt-PEG-SLN-DTX) improved antitumor activity and inhibited tumor growth in C26 tumor bearing mice. Conclusion: These results suggested that PEGylated and aptamer-targeted SLNs containing DTX exhibited efficient characteristics in tumor inhibitory against murine C26 carcinoma model.

Distribution and excretion of a new oral formulation of docetaxel in mice

Distribution and excretion of a new oral formulation of docetaxel in mice

Identification of lipid-phosphatidylserine (PS) as the target of unbiasedly selected cancer specific peptide-peptoid hybrid PPS1.

Phosphatidylserine (PS) is an anionic phospholipid maintained on the inner-leaflet of the cell membrane and is externalized in malignant cells. We previously launched a careful unbiased selection targeting biomolecules (e.g. protein, lipid or carbohydrate) distinct to cancer cells by exploiting HCC4017 lung cancer and HBEC30KT normal epithelial cells derived from the same patient, identifying HCC4017 specific peptide-peptoid hybrid PPS1. In this current study, we identified PS as the target of PPS1. We validated direct PPS1 binding to PS using ELISA-like assays, lipid dot blot and liposome based binding assays. In addition, PPS1 recognized other negatively charged and cancer specific lipids such as phosphatidic acid, phosphatidylinositol and phosphatidylglycerol. PPS1 did not bind to neutral lipids such as phosphatidylethanolamine found in cancer and phosphatidylcholine and sphingomyelin found in normal cells. Further we found that the dimeric version of PPS1 (PPS1D1) displayed strong cytotoxicity towards lung cancer cell lines that externalize PS, but not normal cells. PPS1D1 showed potent single agent anti-tumor activity and enhanced the efficacy of docetaxel in mice bearing H460 lung cancer xenografts. Since PS and anionic phospholipid externalization is common across many cancer types, PPS1 may be an alternative to overcome limitations of protein targeted agents.

Abstract A50: Targeting CXCR4 and CXCR7 to mobilize and kill prostate tumor cells

Abstract Prostate cancer bone metastasis is a lethal incurable disease. Prostate cancer cells home to bone, where they are termed disseminated tumor cells (DTCs) and may reside dormant for years and/or grow into overt metastatic lesions. The bone homing process is largely thought to occur via local signaling of stromal-derived growth factor 1 (SDF1), secreted by osteoblasts within the bone marrow, to C-X-C chemokine receptor 4 (CXCR4), expressed on prostate cancer cells. Hematopoietic stem cells (HSCs) are also recruited to bone via SDF1/CXCR4 signaling. Specifically, HSCs reside in the osteoblastic endosteal niche, where they remain mostly quiescent. We have previously shown that prostate tumor cells occupy this HSC niche, and that the niche affords DTCs a chemoprotective status. Similar to HSCs, prostate DTCs can be mobilized from the niche by inhibiting the SDF1/CXCR4 signaling axis via small molecule CXCR4 inhibitors such as AMD3100 (trade name Plerixafor). Combining CXCR4 antagonism with the microtubule inhibitor docetaxel in mice injected subcutaneously with prostate cancer cells causes greater tumor regression than either compound alone. It is thought that mobilization of DTCs from the bone (we refer to mobilized DTCs as mobDTCs) causes them to proliferate in circulation, causing them to become susceptible to chemotherapy. We are using this strategy in a first-in-man clinical trial; we will treat bone metastatic prostate cancer patients with a potent next-generation CXCR4 antagonist coupled with standard docetaxel treatment. SDF1 also binds to the receptor CXCR7, which is overexpressed on prostate cancer cells as well. It is unknown whether CXCR7 will play a compensatory role when CXCR4 is antagonized. Therefore, it is crucial that we determine individual and overlapping roles of CXCR4 and CXCR7 in prostate cancer cells, particularly during bone metastasis. We hypothesized that CXCR7 can compensate for loss of CXCR4 function. We first assessed CXCR4 and CXCR7 expression across a panel of prostate cancer cell lines. We then stably overexpressed CXCR4 and CXCR7 in prostate cancer PC3 cells and determined classic cellular properties necessary for metastasis in vitro, such as proliferation, migration, and invasion. PC3 cells overexpressing either CXCR4 or CXCR7 had higher proliferation rates relative to PC3 parental cells. In addition, they were more migratory and invasive than parental cells. We are currently working to delete CXCR4 and/or CXCR7 from PC3 cells using the CRISPR-Cas9 system. We will perform in vivo xenograft metastasis experiments using prostate cancer cells with CXCR4 and/or CXCR7 overexpressed or knocked out. We hypothesize that loss of both receptors will be required to prevent bone metastasis. Future work will include small molecule inhibition of both CXCR4 and CXCR7 to mobilize prostate DTCs from bone. Citation Format: Kenneth C. Valkenburg, Sounak Roy, Kenneth J. Pienta. Targeting CXCR4 and CXCR7 to mobilize and kill prostate tumor cells. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Metastasis; 2015 Nov 30-Dec 3; Austin, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(7 Suppl):Abstract nr A50.

Hepatic Uptake Transporters and Docetaxel Disposition in Mice—Letter

We previously reported in Clinical Cancer Research the results of a study evaluating the influence of hepatocellular OATP1B-type uptake transporters on the systemic clearance of docetaxel in mice and patients with inherited, reduced-function variants in the genes encoding these transporters ([1][1

Incorporation of ABCB1-mediated transport into a physiologically-based pharmacokinetic model of docetaxel in mice

Docetaxel is one of the most widely used anticancer agents. While this taxane has proven to be an effective chemotherapeutic drug, noteworthy challenges exist in relation to docetaxel administration due to the considerable interindividual variability in efficacy and toxicity associated with the use of this compound, largely attributable to differences between individuals in their ability to metabolize and eliminate docetaxel. Regarding the latter, the ATP-binding cassette transporter B1 (ABCB1, PGP, MDR1) is primarily responsible for docetaxel elimination. To further understand the role of ABCB1 in the biodistribution of docetaxel in mice, we utilized physiologically-based pharmacokinetic (PBPK) modeling that included ABCB1-mediated transport in relevant tissues. Transporter function was evaluated by studying docetaxel pharmacokinetics in wild-type FVB and Mdr1a/b constitutive knockout (KO) mice and incorporating this concentration-time data into a PBPK model comprised of eight tissue compartments (plasma, brain, heart, lung, kidney, intestine, liver and slowly perfused tissues) and, in addition to ABCB1-mediated transport, included intravenous drug administration, specific binding to intracellular tubulin, intestinal and hepatic metabolism, glomerular filtration and tubular reabsorption. For all tissues in both the FVB and KO cohorts, the PBPK model simulations closely mirrored the observed data. Furthermore, both models predicted AUC values that were with 15% of the observed AUC values, indicating that our model-simulated drug exposures accurately reflected the observed tissue exposures. Overall, our PBPK model furthers the understanding of the role of ABCB1 in the biodistribution of docetaxel. Additionally, this exemplary model structure can be applied to investigate the pharmacokinetics of other ABCB1 transporter substrates.

Plasma, tumor and tissue pharmacokinetics of Docetaxel delivered via nanoparticles of different sizes and shapes in mice bearing SKOV-3 human ovarian carcinoma xenograft

The particle fabrication technique PRINT® was used to fabricate monodisperse size and shape specific poly(lactide-co-glycolide) particles loaded with the chemotherapeutic Docetaxel. The pharmacokinetics of two cylindrical shaped particles with diameter=80nm; height=320nm (PRINT-Doc-80×320) and d=200nm; h=200nm (PRINT-Doc-200×200) were compared to Docetaxel in mice bearing human ovarian carcinoma SKOV-3 flank xenografts. The Docetaxel plasma exposure was ~20-fold higher for both particles compared to docetaxel. Additionally, the volume of distribution (Vd) of Docetaxel in PRINT formulations was ~18-fold (PRINT-Doc-80×320) and ~33-fold (PRINT-Doc-200×200) lower than Docetaxel. The prolonged duration of Docetaxel in plasma when dosed with PRINT formulations subsequently led to increased tumor exposure of Docetaxel from 0 to 168h (~53% higher for PRINT-Doc-80×320 and ~76% higher for PRINT-Doc-200×200 particles). PRINT-Doc-80×320 had lower exposures in the liver, spleen and lung compared with PRINT-Doc-200×200. Thus, the use of particles with smaller feature size may be preferred to decrease clearance by organs of the mononuclear phagocyte system. From the Clinical EditorIn this study, the plasma, tumor, and tissue pharmacokinetics of different Docetaxel nanoparticles of precise shape and size were characterized in mice with human ovarian carcinoma xenograft. It is concluded that the use of particles with smaller feature size may be preferred to decrease clearance by organs of the mononuclear phagocyte system.

Efficacy of GM-CSF-producing Tumor Vaccine after Docetaxel Chemotherapy in Mice Bearing Established Lewis Lung Carcinoma

In this report, we evaluated the efficacy of a GM-CSF-producing tumor vaccine given before and after docetaxel in mice bearing established lung tumors. Mice bearing established 3LL tumors were treated with docetaxel and tumor vaccines transduced with either control or GM-CSF adenoviral vectors. Docetaxel (5-20 mg/kg) treatment alone had only a minimal effect on growth of established 3LL tumors in vivo, although docetaxel was cytotoxic to 3LL cells in vitro. When mice bearing established 3LL tumors were pretreated with docetaxel followed by vaccination with irradiated GM-CSF- transduced 3LL tumor cells, significant tumor regression and prolonged survival were observed compared with chemotherapy alone. Delaying docetaxel treatment until after tumor vaccination abrogated the vaccine's anti-tumor effects. Mice that survived treatment were able to resist a lethal rechallenge of 3LL tumor cells. Memory CTL specific for an epitope (MUT-1) derived from 3LL were detected in surviving mice. Docetaxel induced a mild lymphodepletion in mice, both CD4 and CD8 subsets were reduced in LN and spleens. Interestingly, docetaxel also diminished the number of memory CD8+ T cells (CD122+) and possible CD4+ CD25+ Foxp3+ natural Treg cells. Docetaxel treatment did not affect antigen-driven proliferation of naive T cells but significantly promoted survival of activated T cells. Thus, augmentation of vaccine induced antitumor immunity in docetaxel-treated mice primarily due to the enhanced survival of antigen-experienced T cells.

Construction of Optimal Combined Chemotherapy of Anti-tumor Drugs Based on Chronotherapy

Metastatic breast cancer (MBC) is almost always incurable, and the median survival is of the order on 18-24 months. Combination therapy with adriamycin (ADR) and docetaxel (DOC) is more effective against MBC than the previous therapy due to differences between their mechanisms. However, the combination of ADR and DOC induces severe adverse effects, limiting its clinical use in many patients with MBC. The biologic functions of most living organisms are organized along an approximate 24 h time cycle or circadian rhythm. Chronotherapy is defined as the administration of medications using biological rhythms to optimize the therapeutic outcomes and/or control adverse effects. To decrease adverse effects, many antitumor drugs have been particularly studied in humans and animals. The toxicities of ADR and DOC have also been found to depend on dosing-time in animals and humans. This study was to establish the most suitable dosing schedule to relieve severe adverse effects and improve antitumor effects by considering a chronopharmacological approach, dosing-interval and dosing-sequence to the combination chemotherapy of ADR and DOC in mice. In the results, we demonstrate that the dosing schedule based on dosing-sequence, dosing-interval and dosing-time not only significantly reduced leukopenia and toxic death but also significantly increased the inhibition rate of tumor growth compared with the dosing schedule without an interval between each injection, commonly used in clinical practice. These findings suggest that the therapeutic index of combined chemotherapy can be improved by choosing an optimal dosing-schedule (dosing-interval, dosing-sequence and dosing-time).

Metabolism of docetaxel in mice

Previous studies have shown by quantification of the parent drug and the known metabolites M-1, M-2, M-3 and M-4 that the mass balance of docetaxel in mice and humans is not complete. We therefore used reversed-phase high-performance liquid chromatography (HPLC) with photodiode array (PDA) detection and tandem mass spectrometry to trace and identify putative metabolites in the feces and bile of mice injected intravenously with docetaxel. HPLC-PDA revealed two metabolic products in the feces and more than ten potential new metabolites in the bile. Mass spectrometry was performed on docetaxel reference compound, on the known metabolites M-1, M-2, M-3 and M-4, and on HPLC eluate fractions containing metabolic products, six fractions originating from the bile and two from the feces. The mass spectra of the most abundant unknown metabolite in the bile and the feces were identical, and indicated that this structure contained a carboxyl moiety at the tert-butyl group. Under the conditions of storage this product degraded to metabolite M-4. All other unknown metabolites found in the bile samples were oxidized products, with the oxidations in both the C-13 side chain and the baccatin structure, the latter being a new finding.

Influence of dosing schedule on toxicity and antitumor effects of a combination of adriamycin and docetaxel in mice.

Although the combination of Adriamycin (ADR) and docetaxel (DOC) showed a better cure rate against metastatic breast cancer in a clinical study, severe myelosuppression and cardiotoxicity were dose-limiting factors. The purpose of this study was to establish the most suitable dosing schedule to relieve severe adverse effects and improve the antitumor effects. Both ADR and DOC were administered simultaneously in the simultaneous-dosing group (ADR/DOC), whereas in the intermittent-dosing groups (ADR-DOC and DOC-ADR), the second drug was administered 12 h after the first drug. Leukocyte counts and survival were measured to estimate adverse effects. After administration, ADR and DOC concentrations in blood, myelocyte cells, and heart were determined. To clarify the antitumor effect, tumor growth was measured in Ehrlich-cell-bearing mice after the initiation of drug injections. The simultaneous-dosing group showed severe leukopenia compared with the saline-treated group. However, the toxicity was reduced in the intermittent-dosing groups. The DOC-ADR group showed the best survival rate in the dosing groups. In the pharmacokinetic study, ADR and DOC concentrations in plasma, myelocyte cells, and the heart were markedly higher in the simultaneous-dosing group than the intermittent-dosing groups. These results indicate that pharmacokinetic interactions may contribute to the change in leukopenia induced by concurrent administration of ADR and DOC. The antitumor effect in the DOC-ADR group was the highest in the dosing groups. In the present study, the findings suggest that ADR administered 12 h after DOC injection (DOC-ADR group) not only inhibits tumor growth more strongly but also significantly reduces leukopenia compared with results for the simultaneous-dosing (ADR/DOC) group and significantly reduced the number of toxic deaths compared with the other groups.