The role of ginger's extract and N-acetylcysteine against docetaxel-induced oxidative stress and genetic disorder.

Oxidative stress plays a prominent role in expanding toxicity and various diseases. This study investigated the potential protective effects of ginger (Zingiber officinale) rhizome extract and NAC on docetaxel induced genotoxicity and oxidative stress. The antioxidant power of NAC and ginger extract on the genetic toxicity induced by docetaxel was assessed by micronucleus test. The ROS test with DCFH reagent was used to assess the reactive oxygen species. The thiobarbituric acid method was used to evaluate the amount of MDA produced by docetaxel. The amounts of phenol and flavonoids in the ginger extracts were also evaluated. The amount of phenol in the ginger extract was 0.886 mg of gallic acid per gram of dry extract. The amount of flavonoids were 0.242 mg/mL of quercetin per gram of dry extract. As shown by the micronucleus results, concentrations of 100 and 500 µM NAC and all concentrations of the ginger extract significantly reduced the number of micronuclei produced by docetaxel. On the other hand, the results of oxidative stress tests (ROS and LPO) showed that docetaxel in HGF cells increased the production of ROS and LPO, and the concentrations of ginger extract and NAC decreased oxidative stress in HGF cells in a dose-dependent manner. The results indicate that using these two antioxidants helps inhibit genetic toxicity and oxidative stress caused by docetaxel.

Inflammatory markers S100A8/A9 and metabolic alteration for evaluating signs of early phase toxicity of anticancer agent treatment.

Anticancer agents can cause various side effects, including tissue damages/inflammatory reactions. Drug-responsive biomarkers are essential for evaluating drug toxicity in disease processes. S100 calcium-binding proteins A8/A9 (S100A8/A9) are highly expressed in neutrophils and monocytes/macrophages accumulated at inflammatory sites and are known to be related to tissue damage/inflammation; however, their response to drug toxicity has not been reported. Herein, we investigated the effects of anticancer agents (doxorubicin, cisplatin, and docetaxel) on S100A8/A9 gene expression profiles in four representative tissues (heart, kidney, liver, and lung) in normal C57BL/6J mice. Both S100A8/A9 expression was transiently or time-dependently elevated in four tissues within 48 h after dosing of the three anticancer agents under toxicity-inducing conditions. S100A8/A9 patterns differed among agents and tissues. This result suggests that S100A8/A9 is useful for evaluating anticancer agent-induced tissue damage. Metabolomic analysis revealed that some metabolites showed temporal patterns similar to that of S100A8/A9 expression. The amounts of fumarate (doxorubicin-treated heart), tyrosine (cisplatin-treated kidney), acetylcarnosine (doxorubicin-treated liver), and 2-phosphoglycerate (docetaxel-treated lung) showed similar patterns to that of S100A8/A9 expression. Although these metabolites showed different behaviors between tissues and serum, they may be useful marker candidates for evaluating anticancer agent-induced tissue damage at an earlier stage after dosing.

Cognitive impairment resulting from treatment with docetaxel, doxorubicin, and cyclophosphamide.

Breast cancer is the most commonly diagnosed cancer among women and it is estimated that about 30% of newly diagnosed cancers in women will be breast cancers. While advancements in treating breast cancer have led to an average 5-year survival rate of 90%, many survivors experience cognitive impairments as a result of chemotherapy treatment. Doxorubicin, cyclophosphamide, and docetaxel (TAC) are commonly administered as breast cancer treatments; however, there are few studies that have tested the cognitive effects of TAC. In the current study, 12-week-old female C57BL/6 mice received 4 weekly intraperitoneal injections of either saline or a combination therapy of doxorubicin and cyclophosphamide followed by 4 weekly docetaxel injections. Four weeks after the last injection, mice were tested for hippocampus-dependent cognitive performance in the Y-maze and the Morris water maze. During Y-maze testing, mice exposed to TAC exhibited impairment. During the water maze assessment, all animals were able to locate the visible and hidden platform locations. However, mice that received the TAC presented with a significant impairment in spatial memory retention on the probe trial days. TAC treatment significantly decreases the dendritic complexity of arborization in the dentate gyrus region of the hippocampus. In addition, comparative proteomic analysis revealed downregulation of proteins within key metabolic and signaling pathways associated with cognitive dysfunction, such as oxidative phosphorylation, ephrin signaling, and calcium signaling.

Biodegradable and biocompatible polymeric nanoparticles for enhanced solubility and safe oral delivery of docetaxel: In vivo toxicity evaluation.

Docetaxel (DTX) is a chemotherapeutic drug with poor hydrophilicity and permeability. Its lipophilic properties decrease its absorption in systemic circulation which hinders its therapeutic efficacy & safety. Cyclodextrins (CDs) with their unique structural properties enhance solubility of chemotherapeutic drugs. The study was designed to formulate docetaxel-cyclodextrins inclusion complexes for enhancement of solubility with sulfobutyl ether ß-cyclodextrin (SBE7-ß-CD), hydroxypropyl ß-cyclodextrin (HP-ß-CD) and ß-cyclodextrin (ß-CD). Further, by using ionic gelation method polymeric nanoparticles of docetaxel-cyclodextrins were prepared with sodium tri poly phosphate (STPP) and chitosan (CS). Optimization is performed by varying CS and STPP mass ratios. Nanoparticles were analyzed for their physicochemical properties, drug-excipient compatibility, thermal stability and oral toxicity. CDs enhanced the solubility of DTX. Nanoparticles were found within 144.8 ± 65.19 - 372.0 ± 126.9 nm diameters with polydispersity ranging 0.117-0.375. The particles were found round & circular in shape with smooth and non-porous surface. Increased quantity of drug release was observed from DTX-CDs loaded nanoparticles than pure drug loaded nanoparticles. Oral toxicity in rabbits revealed biochemical, histopathological profile with no toxic effect on cellular structure of animals.

Treatment of electrical wrist stimulation reduces chemotherapy-induced neuropathy and ultrasound vocalization via modulation of spinal NR2B phosphorylation.

Docetaxel, a chemotherapeutic agent used to treat breast cancer, produces a robust painful neuropathy that is aggravated by mechanical and thermal stimuli. This study was undertaken to investigate the analgesic effects of electrical stimulation on docetaxel-induced neuropathic pain in mice and to identify associated changes in ultrasound vocalizations. Peripheral neuropathy was induced with intraperitoneally injected docetaxel (5 mg/kg) on 3 times every 2 days in male ICR mice. Electrical wrist stimulation was administered and pain behavior signs were evaluated by von Frey filaments and thermal stimulation on the hind paw. Ultrasound vocalizations were measured using ultrasound microphones, after electrical stimulation. After mice developed docetaxel-induced neuropathic pain behavior, an electrical stimulation temporarily attenuated mechanical allodynia and thermal hyperalgesia. In formalin and NMDA test, pain-induced mice showed increases in 10-30 kHz ultrasound vocalizations, but not in 30-50 and 50-80 kHz vocalizations. Treatment with docetaxel selectively increased 10-30 kHz ultrasound vocalizations, whereas electrical stimulation caused a meaningful decrease. Moreover, electrical stimulation suppressed the docetaxel-enhanced phosphorylation of the NMDA receptor NR2B subunit in the spinal dorsal horn. These results of the analgesic effect of electrical stimulation in chemotherapy-induced neuropathy could potentially provide a new method to treat and manage peripheral neuropathy in patients with cancer.

Comparative analysis of docetaxel: physical and chemical characterisation of Taxotère® and generics.

Several cases of fatal enterocolitis have been described in association with the use of docetaxel (DTX), and this increase in adverse events has been concomitant with a change in formulation. Indeed in 2010, a new DTX-based presentation has been introduced in the form of a single ready-to-use vial by Sanofi-Aventis, presentation also used for generics. In this study, different available formulations were compared (Sanofi 2 vials, Sanofi 1 vial, Accord Healthcare, Kabi, Hospira) in terms of composition compliance with control specifications and simulated micelle behaviour to try to determine what could be the potential causes of this problem. This work had permitted to show that all the tested products complied with specifications in terms of dosage and purity. Variations in the composition of polysorbate 80 (PS80) have been observed but are probably too small to be responsible for the toxicity found in patients. However, we identified a difference in micelle size and release kinetics probably because of doubling concentration of ethanol in new formulation. As a result, we emphasised the importance in the case of DTX of conducting bioequivalence studies as expected in European Medicines Agency (EMA) guidance to ensure patient safety, even though these formulation changes might seem minor. Therefore, further studies are needed to explore the potential role of ethanol, PS80 and the unbound fraction of DTX in the development of enterocolitis in patients treated with DTX.

Quantification of the pharmacokinetic-toxicodynamic relationship of oral docetaxel co-administered with ritonavir.

Introduction Oral formulations of docetaxel have successfully been developed as an alternative for intravenous administration. Co-administration with the enzyme inhibitor ritonavir boosts the docetaxel plasma exposure. In dose-escalation trials, the maximum tolerated doses for two different dosing regimens were established and dose-limiting toxicities (DLTs) were recorded. The aim of current analysis was to develop a pharmacokinetic (PK)-toxicodynamic (TOX) model to quantify the relationship between docetaxel plasma exposure and DLTs. Methods A total of 85 patients was included in the current analysis, 18 patients showed a DLT in the four-week observation period. A PK-TOX model was developed and simulations based on the PK-TOX model were performed. Results The final PK-TOX model was characterized by an effect compartment representing the toxic effect of docetaxel, which was linked to the probability of developing a DLT. Simulations of once-weekly, once-daily 60 mg and once-weekly, twice-daily 30 mg followed by 20 mg of oral docetaxel suggested that 14% and 34% of patients, respectively, would have a probability >25% to develop a DLT in a four-week period. Conclusions A PK-TOX model was successfully developed. This model can be used to evaluate the probability of developing a DLT following treatment with oral docetaxel and ritonavir in different dosing regimens.

Clinical impact of baseline renal function on the safety of radiotherapy with concurrent docetaxel for esophageal cancer in elderly patients.

BACKGROUND: We aimed to compare the safety of radiotherapy with concurrent docetaxel (DOC-RT) for esophageal cancer (EC) in elderly patients who were divided into a creatinine clearance (Ccr) < 60 mL/min (Ccr-L) group and a Ccr ≥ 60 mL/min (Ccr-H) group. METHODS: Eligible patients included those aged ≥ 76 years who were diagnosed with esophageal squamous cell carcinoma. The patients received radiotherapy (60 Gy in 30 fractions) and concurrent docetaxel (10 mg/m2 weekly for six cycles), after which toxicity and treatment completion rates were retrospectively evaluated. RESULTS: The 73 elderly EC patients receiving DOC-RT were divided into two groups for evaluation: the Ccr-L group (49 patients) and the Ccr-H group (24 patients). The median survival time for patients in the Ccr-L and Ccr-H groups was 21 and 20 months, respectively (p = 0.2). The incidence of grade 1 acute kidney injury was 8% vs. 8% (p = 1) in the Ccr-L and Ccr-H groups, respectively. No other hematological or nonhematological toxicities differed between patients in the two groups. No grade 4 or 5 toxicities were observed in the two groups. No significant difference was observed in the treatment completion rates (88% vs. 92%, p = 1) between patients in the Ccr-L and Ccr-H groups. CONCLUSIONS: Regardless of baseline renal function, DOC-RT is a safe regimen for elderly patients with EC.

Role of 1-Deoxysphingolipids in docetaxel neurotoxicity.

A major dose-limiting side effect of docetaxel chemotherapy is peripheral neuropathy. Patients' symptoms include pain, numbness, tingling and burning sensations, and motor weakness in the extremities. The molecular mechanism is currently not understood, and there are no treatments available. Previously, we have shown an association between neuropathy symptoms of patients treated with paclitaxel and the plasma levels of neurotoxic sphingolipids, the 1-deoxysphingolipids (1-deoxySL) (Kramer et al, FASEB J, 2015). 1-DeoxySL are produced when the first enzyme of the sphingolipid biosynthetic pathway, serine palmitoyltransferase (SPT), uses L-alanine as a substrate instead of its canonical amino acid substrate, L-serine. In the current investigation, we tested whether 1-deoxySL accumulate in the nervous system following systemic docetaxel treatment in mice. In dorsal root ganglia (DRG), we observed that docetaxel (45 mg/kg cumulative dose) significantly elevated the levels of 1-deoxySL and L-serine-derived ceramides, but not sphingosine-1-phosphate (S1P). S1P is a bioactive sphingolipid and a ligand for specific G-protein-coupled receptors. In the sciatic nerve, docetaxel decreased 1-deoxySL and ceramides. Moreover, we show that in primary DRG cultures, 1-deoxysphingosine produced neurite swellings that could be reversed with S1P. Our results demonstrate that docetaxel chemotherapy up-regulates sphingolipid metabolism in sensory neurons, leading to the accumulation of neurotoxic 1-deoxySL. We suggest that the neurotoxic effects of 1-deoxySL on axons can be reversed with S1P.

Tissue Distribution and Systemic Toxicity Evaluation of Raloxifene Targeted Polymeric Micelles of Poly (Styrene-Maleic Acid)-Poly (Amide- Ether-Ester-Imide)-Poly (Ethylene Glycol) Loaded With Docetaxel in Breast Cancer Bearing Mice.

BACKGROUND: Due to the low water solubility of Docetaxel (DTX), it is formulated with ethanol and Tween 80 with lots of side effects. For this reason, special attention has been paid to formulate it in new drug nano-carriers. OBJECTIVE: The goal of this study was to evaluate the safety, antitumor activity and tissue distribution of the novel synthesized Raloxifene (RA) targeted polymeric micelles. METHODS: DTX-loaded RA-targeted polymeric micelles composed of poly(styrene-maleic acid)- poly(amide-ether-ester-imide)-poly(ethylene glycol) (SMA-PAEE-PEG) were prepared and their antitumor activity was studied in MC4-L2 tumor-bearing mice compared with non-targeted micelles and free DTX. Safety of the micelles was studied by Hematoxylin and Eosin (H&E) staining of tumors and major organs of the mice. The drug accumulation in the tumor and major organs was measured by HPLC method. RESULTS: The results showed better tumor growth inhibition and increased survival of mice treated with DTX-loaded in targeted micelles compared to the non-targeted micelles and free DTX. Histopathological studies, H&E staining of tumors and immunohistochemical examination showed the potential of DTX-loaded RA-targeted micelles to inhibit tumor cells proliferation. The higher accumulation of the DTX in the tumor tissue after injection of the micelles compared to the free DTX may indicate the higher uptake of the targeted micelles by the G-Protein-Coupled Estrogen Receptors (GPER). CONCLUSION: The results indicate that RA-conjugated polymeric micelles may be a strong and effective drug delivery system for DTX therapy and uptake of the drug into tumor cells, and overcome the disadvantages and side effects of conventional DTX.

Nanoparticles from Gantrez® AN-poly(ethylene glycol) conjugates as carriers for oral delivery of docetaxel.

The oral delivery of docetaxel (DTX) is challenging due to a low bioavailability, related to an important pre-systemic metabolism. With the aim of improving the bioavailability of this cytotoxic agent, nanoparticles from conjugates based on the copolymer of methyl vinyl ether and maleic anhydride (poly(anhydride)) and two different types of PEG, PEG2000 (PEG2) or methoxyPEG2000 (mPEG2), were evaluated. Nanoparticles, with a DTX loading close to 10%, were prepared by desolvation and stabilized with calcium, before purification and lyophilization. For the pharmacokinetic study, nanoparticles were orally administered to mice at a single dose of 30 mg/kg. The plasma levels of DTX were high, prolonged in time and, importantly, quantified within the therapeutic window. The relative oral bioavailability was calculated to be up to 56% when DTX was loaded in nanoparticles from poly(anhydride)-mPEG2000 conjugate (DTX-NP-mPEG2). Finally, a comparative toxicity study between equitoxic doses of free iv DTX and oral DTX-NP-mPEG2 was conducted in mice. Animals orally treated with DTX-loaded nanoparticles displayed less severe signs of hypersensitivity reactions, peripheral neurotoxicity, myelosuppression and hepatotoxicity than free iv docetaxel. In summary, poly(anhydride)-PEG conjugate nanoparticles appears to be adequate carries for the oral delivery of docetaxel.

Effect of the Phragmitis Rhizoma Aqueous Extract on the Pharmacokinetics of Docetaxel in Rats.

BACKGROUND: Traditionally, Phragmitis rhizoma has been prescribed to relive a fever, vomiting, dysuria, and constipation, and to promote secretion of fluids. In addition, recent studies have reported its efficacy as a diuretic and antiemetic. Our previous study demonstrated that the Phragmitis rhizoma aqueous extract (EPR) ameliorates docetaxel (DTX)-induced myelotoxicity. AIM AND OBJECTIVE: This study was aimed to investigate the effects of EPR on the pharmacokinetics of DTX in Sprague-Dawley rats. MATERIALS AND METHODS: The animals received an intravenous injection of DTX (5 mg/kg) with or without oral EPR (100 mg/kg) pretreatment for 1 or 6 days. The pharmacokinetics of plasma DTX was analyzed using an ultra-performance liquid chromatography-tandem mass spectrometry system, and pharmacokinetic parameters were estimated via noncompartmental analysis. RESULTS: Relative to the control group (DTX alone), EPR pretreatment did not affect significantly the overall profiles of plasma DTX levels. Consecutively pretreated EPR for 6 days slightly altered AUC0-t and Cmax of DTX by 122 and 145.9%, respectively, but these data did not reach the threshold of statistical significance (p > 0.05). CONCLUSION: These results indicate that DTX exposure may not be affected by EPR treatment at the dose level used in this study, suggesting that oral EPR can be used safely when taken with intravenously injected DTX. However, further studies under the stringent conditions are needed when chronic treatment of EPR and anticancer drug.

Development of synthetic high-density lipoprotein-based ApoA-I mimetic peptide-loaded docetaxel as a drug delivery nanocarrier for breast cancer chemotherapy.

In this study, a synthetic high-density lipoprotein (sHDL), peptide-based nanocarrier loaded with docetaxel (DTX) was constructed, against breast cancer. The thermodynamic and molecular dynamic analyses were conducted to examine the stability of nanoparticles synthesized from mimetic peptide 5 A and various types of phospholipids. Furthermore, the cellular uptake and in vivo fluorescence imaging analysis experiments, with scavenger receptor B-I (SR-BI) were carried out to examine the tumor-targeting ability of sHDL. The nanoparticles were investigated for their pharmacodynamic and cytotoxic effects to show their effectivity as anti-tumor agents. The results showed that the synthesized sHDL nanoparticles exhibited a high payload of DTX, sustained drug release properties, and excellent biocompatibility. Moreover, DTX-sHDL nanoparticles enhanced the uptake of DTX, increased the cytotoxicity against MCF-7 cells, and reduced the off-target side-effects to normal cells. Finally, experiments in 4T1 cell line-bearing mice indicate that inhibition of tumor growth by DTX-sHDL nanoparticles was superior to that of free DTX group. Thus, the sHDL nanoparticles are a promising drug delivery vehicle for improving the efficacy of anti-cancer drugs.

Prediction of docetaxel toxicity in older cancer patients: a Bayesian network approach.

Chemotherapy is an essential therapy in the fight against cancer. Polypathology and polymedication are often encountered in elderly patients, making this population especially at risk for adverse drug reactions, and particularly with cytotoxic drugs. The objective of this study was to build a model to predict high-grade toxicity in elderly patients treated with docetaxel. Data from the trial TAX-108 have been used to create the model. The variable to predict was the occurrence of grade 3 or 4 toxicity. The explanatory variables entered in the model were anthropometric and biological characteristics of patients at inclusion; fragility criteria (SMAF, CIRS-G, performance status); location of the primary tumor; chemotherapy history, radiotherapy or surgery; weekly dose of docetaxel, cumulative dose administered. A Bayesian network model was developed using a global search procedure and an Expectation-Maximization algorithm. A 10-fold cross-validation was performed. A toxicity of grade 3 or higher was observed in 54% of patients. The variables providing the most information were the primary site (19.4%), the dose per course (17.5%), and albuminemia (13.1%). The area under the curve of the model obtained after cross-validation was 74 ± 1.4%. The model built allows classifying correctly 71.21 ± 0.9% of patients in our sample in the cross-validation procedure. The sensitivity and specificity of the model were 75 and 67%, respectively, and the positive and negative predictive values were 73 and 69%. The encouraging results from this first study show that Bayesian networks could help assess the benefit-risk ratio of chemotherapy in elderly patients.

Ionically Cross-Linked Chitosan Nanoparticles for Sustained Delivery of Docetaxel: Fabrication, Post-Formulation and Acute Oral Toxicity Evaluation.

INTRODUCTION: Polymeric nanoparticles are potential carriers for the efficient delivery of hydrophilic and hydrophobic drugs due to their multifaceted applications. Docetaxel is relatively less hydrophobic and twice as potent as paclitaxel. Like other taxane chemotherapeutic agents, docetaxel is not well tolerated and shows toxicity in the patients. Nanoencapsulation of potent chemotherapeutic agents has been shown to improve tolerability and therapeutic outcome. Therefore, the present study was designed to fabricate chitosan and sodium tripolyphosphate (STPP) based on ionically cross-linked nanoparticles for sustained release of docetaxel. METHODS: Nanoparticles were prepared by the ionic-gelation method by dropwise addition of the STPP solution into the chitosan solution in different ratios. CNPs were characterized for post-formulation parameters like size, zeta potential, scanning electron microscope (SEM), FTIR, DSC/TGA, pXRD, and in-vitro drug release, as well as for acute oral toxicity studies in Wistar rats. RESULTS AND DISCUSSION: The optimized docetaxel loaded polymeric nanoparticles were in the size range (172.6nm-479.65 nm), and zeta potential (30.45-35.95 mV) required to achieve enhanced permeation and retention effect. In addition, scanning electron microscopy revealed rough and porous surface, whereas, FTIR revealed the compatible polymeric nanoparticles. Likewise, the thermal stability was ensured through DSC and TG analysis, and powder X-ray diffraction analysis exhibited solid-state stability of the docetaxel loaded nanoparticles. The in-vitro drug release evaluation in phosphate buffer saline (pH 7.4) showed sustained release pattern, i.e. 51.57-69.93% within 24 hrs. The data were fitted to different release kinetic models which showed Fickian diffusion as a predominant release mechanism (R2 = 0.9734-0.9786, n= 0.264-0.340). Acceptable tolerability was exhibited by acute oral toxicity in rabbits and no abnormality was noted in growth, behavior, blood biochemistry or histology and function of vital organs. CONCLUSION: Ionically cross-linked chitosan nanoparticles are non-toxic and biocompatible drug delivery systems for sustained release of chemotherapeutic agents, such as docetaxel.

Improved antitumor efficacy and reduced toxicity of docetaxel using anacardic acid functionalized stealth liposomes.

Potential toxicity due to nonspecific distribution is one of the major challenges with currently available chemotherapeutics. In the present report we have developed Docetaxel (DTX) loaded Anacardic acid (AA) functionalized liposomes (DTX-AA-PEG-Liposomes) to have the advantage of selective distribution to cancer cells due to recognition and enhanced uptake by VEGF receptors. AA dual conjugate (AA-PEG-AA) was synthesized by using carbodiimide chemistry and further used to formulate the AA functionalized DTX loaded liposomes by using film hydration method. Extensive optimization of different process variables resulted in the formation of liposomes with particle size 126.4 ± 6.2 nm and PDI 0.239 ± 0.03. The freeze dried DTX-AA-PEG-Liposomes demonstrated sustained release for up to 24 h and excellent stability at accelerated storage stability conditions. Qualitative cell uptake studies demonstrated remarkably higher cellular uptake of Coumarin-6 (C-6) loaded liposomes, while quantitative determination revealed 2.64 and 2.88-fold higher uptake of DTX-AA-PEG-Liposomes in comparison with free DTX. Cell culture studies in MCF-7 to determine cellular uptake mechanism demonstrated clathrin and caveolae mediated internalization of liposomes, independent of Organic Anion Transporting Polypeptides (OATPs) transporters. Moreover, developed liposomes demonstrated relatively higher cell inhibition and apoptosis in MCF-7 cells as compared to free DTX. Furthermore, in vivo pharmacokinetics demonstrated 3.7 and 4.5-fold increase in AUC and t1/2 value of DTX-AA-PEG-Liposomes as compared to Taxotere®, respectively. Moreover, DTX-AA-PEG-Liposomes demonstrated significant reduction in tumor volume and toxicity in comparison with marketed formulation (Taxotere®), confirming enhanced efficacy and safety of the developed formulation.

Cabazitaxel regimens inhibit the growth of prostate cancer cells and enhances the anti-tumor properties of PEDF with various efficacy and toxicity.

BACKGROUND: Taxanes chemotherapies represent the major therapeutic alternative for symptomatic mCRPC. While docetaxel is the most commonly prescribed Taxane for mCRPC; cabazitaxel has been approved for patients unresponsive to docetaxel. Still mCRPC remains incurable and patients often experience severe side effects. Recently, the FIRSTANA trial first demonstrated the absence of superiority in overall survival between cabazitaxel and docetaxel in mCRPC patients. Inversely, different toxicity were reported suggesting that cabazitaxel may provide a first line treatment option for some patients urging for a deeper characterization of cabazitaxel mechanisms of action as well as a re-evaluation of cabazitaxel conventional dose and schedule. In this study, our goal was therefore to evaluate the anti-tumor efficacy of various cabazitaxel regimens delivered as monotherapy or in combination with PEDF, a known anti-angiogenic and anti-neoplastic agent. METHODS: CRPC cells undergoing Taxane treatment were evaluated for cell proliferation, migration and death, and apoptosis using crystal violet staining, chemotaxis, cell cycle, and TUNEL assays. In vitro data were corroborated in CL1 CRPC xenografts where mice received intermittent or metronomic low-doses cabazitaxel ± PEDF. RESULTS: We found that cabazitaxel inhibits the proliferation of CRPC cells with a higher efficacy than docetaxel in vitro. As expected, high-doses of Taxanes blocked the cells in mitosis. Surprisingly, low-doses of cabazitaxel induced more cell death than docetaxel mainly through apoptosis. In vivo, intermittent cabazitaxel lead to disease stabilization when combined with PEDF. Unexpectedly, low-doses of cabazitaxel delayed tumor growth with severe toxicity for some of the doses tested. Other results showed that PEDF and low-doses of cabazitaxel combination inhibited the migration of tumor cell and increased the tumoricidal activity of macrophages toward prostate tumor cells. CONCLUSIONS: Our findings highlight the great promise of cabazitaxel drug and predict a possible move of cabazitaxel forward within the therapeutic sequence of prostate cancer.

Highly efficacious and specific anti-glioma chemotherapy by tandem nanomicelles co-functionalized with brain tumor-targeting and cell-penetrating peptides.

Glioma is a highly challenging human malignancy as drugs typically exhibit a low blood-brain barrier (BBB) permeability as well as poor glioma selectivity and penetration. Here, we report that tandem nanomicelles co-functionalized with brain tumor-targeting and cell-penetrating peptides, Angiopep-2 and TAT, enable a highly efficacious and specific anti-glioma chemotherapy. Interestingly, tandem nanomicelles with 20 mol% Angiopep-2 and 10 mol% TAT linked via long and short poly(ethylene glycol)s, respectively, while maintaining a high glioma cell selectivity display markedly enhanced BBB permeation, glioma accumulation and penetration, and glioma cell uptake. We further show that docetaxel-loaded tandem nanomicelles have a long blood circulation time in mice and significantly better inhibit orthotopic U87MG human glioma than the corresponding Angiopep-2 single peptide-functionalized control, leading to an improved survival rate with little adverse effects. These tandem nanomicelles uniquely combining brain tumor-targeting and cell-penetrating functions provide a novel and effective strategy for targeted glioma therapy.

Oestrogen receptor-mediated liposomal drug delivery for treating melanoma.

Function of steroid hormone oestrogen that transactivates oestrogen receptor (ER) is expressed in multiple organs. Except for malignancies of gynaecological organs, ER remains largely unutilised as a target to treat cancers of ER-expressing brain, prostate, skin etc. We have previously developed oestrogen targeting cationic lipid molecule (ES-C10), which showed targeted killing of ER + breast and skin cancer cells. In this study, we explored the targeting ability of ES-C10 as a ligand as well as its additive killing effect (if any), when incorporated in two different liposomes (DCME and DCDE), carrying two anticancer molecules MCIS3 and Docetaxel™, respectively. DCME and DCDE exhibited higher cytotoxicity in ER + cancer cells than in ER - cancer or in non-cancer cells. Both liposomes induced ER-mediated cytotoxicity and caspase 3-induced apoptosis in ER + melanoma cells. Further, decreased levels of pAkt, and increased levels of PTEN and p53 were also observed. Both the targeted liposomes were least haemolytic. These selectively delivered drug-cargoes to tumour mass over other vital organs and induced better anti-tumour effect, which led to increased survivability than their respective controls. In conclusion, we demonstrated the development of two independent liposomal drug-delivery systems associated with an anticancer, oestrogen-structure based ligand for efficient, ER-mediated anti-melanoma effect.

Phosphatidylcholine attenuated docetaxel-induced peripheral neurotoxicity in rats.

Docetaxel is a taxane chemotherapeutic agent used in the treatment of breast cancer, prostate cancer and gastric cancer, but several side effects such as peripheral neurotoxicity could occur. The present study was designed to investigate the therapeutic potential of phosphatidylcholine (PC) on docetaxel-induced peripheral neurotoxicity. Rats were randomly divided into three groups and treated for 4 weeks. Behavioral tests were conducted to measure the effects of PC on docetaxel-induced decreases in mechanical & thermal nociceptive threshold. Biochemical tests were conducted to measure the level of oxidative stress on sciatic nerve. Histopathological and immunohistochemical experiments were also conducted to assess neuronal damage and glial activation. PC treatment significantly attenuated docetaxel-induced changes in mechanical & thermal nociceptive response latencies. PC decreased oxidative stress in sciatic nerve by increasing antioxidant levels (glutathione, glutathione peroxidase and superoxide dismutase activity). In immunohistochemical evaluation, PC treatment ameliorated docetaxel-induced neuronal damage and microglial activation in the sciatic nerve and spinal cord. Thus, PC showed protective effects against docetaxel-induced peripheral neurotoxicity. These effects may be attributed to its antioxidant properties and modulation of microglia.