Docetaxel: an alternative taxane in ovarian cancer

Gaussian processes modeling for the prediction of polymeric nanoparticle formulation design to enhance encapsulation efficiency and therapeutic efficacy

Conventional drugs have been facing various drug delivery obstacles, including first-pass metabolism for oral medications, drug degradation by cellular enzymes, off-target effects, and cytotoxicity of healthy cells. Nanoparticles (NP) application in drug delivery can compensate for these drawbacks to a great extent. NPs can be fabricated using different materials and structures to achieve desired therapeutic effects. For each type of NP material, its physicochemical properties determine compatibility with specific drugs and other supplemental compositions. The optimized material selection becomes prominent in NP development to improve NP performances. Due to the nature of NP fabrication, the process is long and expensive. To accelerate NP composition optimization, machine learning (ML) techniques are among the most promising methods for efficient data predictions and optimizations.As a proof-of concept, we created Gaussian Process (GP) models to make predictions for drug encapsulation efficiency (EE%) and therapeutic efficacy of 32 poly (lactic-co-glycolic acid) (PLGA) NPs that are formed with materials with different physicochemical properties. Two model drugs, doxorubicin (DOX) and docetaxel (DTX) were loaded separately. The IC50 values for the various NPs formulations were evaluated using the OVCAR3 epithelial ovarian cancer cell line. EE% GP model has the highest prediction accuracy with the lowest normalized root-mean-squared-error (RMSE) of 0.187. The DOX and DTX IC50 GP models have normalized RMSEs of 0.296 and 0.206, respectively, which are higher than that of the EE% GP model.

Differential scanning calorimetry in drug-membrane interactions

Differential Scanning Calorimetry (DSC) is a central technique in investigating drug - membrane interactions, a critical component of pharmaceutical research. DSC measures the heat difference between a sample of interest and a reference as a function of temperature or time, contributing essential knowledge on the thermally induced phase changes in lipid membranes and how these changes are affected by incorporating pharmacological substances. The manuscript discusses the use of phospholipid bilayers, which can form structures like unilamellar and multilamellar vesicles, providing a simplified yet representative membrane model to investigate the complex dynamics of how drugs interact with and penetrate cellular barriers. The manuscript consolidates data from various studies, providing a comprehensive understanding of the mechanisms underlying drug - membrane interactions, the determinants that influence these interactions, and the crucial role of DSC in elucidating these components. It further explores the interactions of specific classes of drugs with phospholipid membranes, including non-steroidal anti-inflammatory drugs, anticancer agents, natural products with antioxidant properties, and Alzheimer's disease therapeutics. The manuscript underscores the critical importance of DSC in this field and the need for continued research to improve our understanding of these interactions, acting as a valuable resource for researchers.

Tyrosine kinase inhibitors (TKIs) for ovarian cancer treatment: from organic to inorganic chemotherapeutics towards selectivity-a perspective overview

Ovarian cancer (OC) is a lethal gynecologic cancer in industrialized countries. Treatments for OC include the surgical removal and chemotherapy. In the last decades, improvements have been made in the surgery technologies, drug combinations and administration protocols, and in diagnosis. However, mortality from OC is still high owing to recurrences and insurgence of drug resistance. Accordingly, it is urgent the development of novel agents capable to effectively target OC. In this respect, tyrosine kinase inhibitors (TKIs) may play an important role. Most of TKIs developed and tested so far are organic. However, owing to their chemical versatility, also metals can be exploited to design selective and potent TKIs. We provide a short and easy-to-read overview on the main organic TKIs with a summary of those that entered clinical trials. Additionally, we describe the potential of metal-based TKIs, focusing on this overlooked family of compounds that may significantly contribute towards the concept of precision-medicine.

Ferroptosis and EMT resistance in cancer: a comprehensive review of the interplay

Ferroptosis differs from traditional cell death mechanisms like apoptosis, necrosis, and autophagy, primarily due to its reliance on iron metabolism and the loss of glutathione peroxidase activity, leading to lipid peroxidation and cell death. The dysregulation of iron metabolism is a hallmark of various cancers, contributing to tumor progression, metastasis, and notably, drug resistance. The acquisition of mesenchymal characteristics by epithelial cells is known as Epithelial-Mesenchymal Transition (EMT), a biological process intricately linked to cancer development, promoting traits such as invasiveness, metastasis, and resistance to therapeutic interventions. EMT plays a pivotal role in cancer progression and contributes significantly to the complex dynamics of carcinogenesis. Research findings indicate that mesenchymal cancer cells exhibit greater susceptibility to ferroptosis compared to their epithelial counterparts. The induction of ferroptosis becomes more effective in eliminating drug-resistant cancer cells during the process of EMT. The interplay between ferroptosis and EMT, a process where epithelial cells transform into mobile mesenchymal cells, is crucial in understanding cancer progression. EMT is associated with increased cancer metastasis and drug resistance. The review delves into how ferroptosis and EMT influence each other, highlighting the role of key proteins like GPX4, which protects against lipid peroxidation, and its inhibition can induce ferroptosis. Conversely, increased GPX4 expression is linked to heightened resistance to ferroptosis in cancer cells. Moreover, the review discusses the implications of EMT-induced transcription factors such as Snail, Zeb1, and Twist in modulating the sensitivity of tumor cells to ferroptosis, thereby affecting drug resistance and cancer treatment outcomes. Targeting the ferroptosis pathway offers a promising therapeutic strategy, particularly for tumors resistant to conventional treatments. The induction of ferroptosis in these cells could potentially overcome drug resistance. However, translating these findings into clinical practice presents challenges, including understanding the precise mechanisms of ferroptosis induction, identifying predictive biomarkers, and optimizing combination therapies. The review underscores the need for further research to unravel the complex interactions between ferroptosis, EMT, and drug resistance in cancer. This could lead to the development of more effective, targeted cancer treatments, particularly for drug-resistant tumors, offering new hope in cancer therapeutics.

A Targeted Thorium-227 Conjugate Demonstrates Efficacy in Preclinical Models of Acquired Drug Resistance and Combination Potential with Chemotherapeutics and Antiangiogenic Therapies

Targeted alpha therapies (TAT) are an innovative class of therapies for cancer treatment. The unique mode-of-action of TATs is the induction of deleterious DNA double-strand breaks. Difficult-to-treat cancers, such as gynecologic cancers upregulating the chemoresistance P-glycoprotein (p-gp) and overexpressing the membrane protein mesothelin (MSLN), are promising targets for TATs. Here, based on the previous encouraging findings with monotherapy, we investigated the efficacy of the mesothelin-targeted thorium-227 conjugate (MSLN-TTC) both as monotherapy and in combination with chemotherapies and antiangiogenic compounds in ovarian and cervical cancer models expressing p-gp. MSLN-TTC monotherapy showed equal cytotoxicity in vitro in p-gp-positive and -negative cancer cells, while chemotherapeutics dramatically lost activity on p-gp-positive cancer cells. In vivo, MSLN-TTC exhibited dose-dependent tumor growth inhibition with treatment/control ratios of 0.03-0.44 in various xenograft models irrespective of p-gp expression status. Furthermore, MSLN-TTC was more efficacious in p-gp-expressing tumors than chemotherapeutics. In the MSLN-expressing ST206B ovarian cancer patient-derived xenograft model, MSLN-TTC accumulated specifically in the tumor, which combined with pegylated liposomal doxorubicin (Doxil), docetaxel, bevacizumab, or regorafenib treatment induced additive-to-synergistic antitumor efficacy and substantially increased response rates compared with respective monotherapies. The combination treatments were well tolerated and only transient decreases in white and red blood cells were observed. In summary, we demonstrate that MSLN-TTC treatment shows efficacy in p-gp-expressing models of chemoresistance and has combination potential with chemo- and antiangiogenic therapies.

Exploring the Potential of Metal-Based Candidate Drugs as Modulators of the Cytoskeleton

During recent years, accumulating evidence suggested that metal-based candidate drugs are promising modulators of cytoskeletal and cytoskeleton-associated proteins. This was substantiated by the identification and validation of actin, vimentin and plectin as targets of distinct ruthenium(II)- and platinum(II)-based modulators. Despite this, structural information about molecular interaction is scarcely available. Here, we compile the scattered reports about metal-based candidate molecules that influence the cytoskeleton, its associated proteins and explore their potential to interfere in cancer-related processes, including proliferation, invasion and the epithelial-to-mesenchymal transition. Advances in this field depend crucially on determining binding sites and on gaining comprehensive insight into molecular drug-target interactions. These are key steps towards establishing yet elusive structure-activity relationships.

Conformation and energy investigation of microtubule longitudinal dynamic instability induced by natural products

The natural products plinabulin, docetaxel, and vinblastine are microtubule targeting agents (MTAs). They have been used alone or in combination in cancer treatment. However, the exact nature of their effects on microtubule (MT) polymerization dynamics is poorly understood. To elucidate the longitudinal conformational and energetic changes during MT dynamics, a total of 140 ns molecular dynamic simulations combined with binding free energy calculations were performed on seven tubulin models. The results indicated that the drugs disrupted MT polymerization by altering both MT conformation and binding free energy of the neighboring tubulin subunits. The combination of plinabulin and docetaxel destabilized MT polymerization due to bending MT and weakening the polarity of tubulin polymerization. The new combination of docetaxel and vinblastine synergistically enhanced MT depolymerization and bending, while plinabulin and vinblastine had no synergistic inhibitory effects. The results were verified by the tubulin assembly assay. Our study obtained a comprehensive understanding of the action mechanisms of three natural drugs and their combinations on MT dynamic, provided theoretical guidance for new MTA combinations, and would promote the optimal use of MTA and contribute to developing new MTAs as anticancer agents.

Cisplatin in Ovarian Cancer Treatment-Known Limitations in Therapy Force New Solutions

Cisplatin is one of the most commonly used anticancer drugs worldwide. It is mainly used in the treatment of ovarian cancer, but also used in testicular, bladder and lung cancers. The significant advantage of this drug is the multidirectional mechanism of its anticancer action, with the most important direction being damaging the DNA of cancer cells. Unfortunately, cisplatin displays a number of serious disadvantages, including toxicity to the most important organs, such as kidneys, heart, liver and inner ear. Moreover, a significant problem among patients with ovarian cancer, treated with cisplatin, is the development of numerous resistance mechanisms during therapy, including changes in the processes of cellular drug import and export, changes in the DNA damage repair mechanisms, as well as numerous changes in the processes of apoptosis and autophagy. Due to all of the mentioned problems, strategies to increase the effectiveness of cisplatin in the treatment of ovarian cancer are intensively sought. The most important strategy includes the development of less toxic cisplatin analogs. Another important direction is combination therapy, involving the simultaneous use of cisplatin with different anticancer drugs, substances derived from plants, temperature or radiotherapy. Many years of observations accompanying the presence of cisplatin in the therapy made it possible to provide a series of verifiable, statistically significant data, but also to show how, over time, with the new information and scientific discoveries, it is possible to describe and understand the therapeutic problems observed in practice, such as the acquisition of drug resistance by tumor cells or induction of changes in the tumor microenvironment. According to the authors, confronting what we knew so far with what new trends offer has a profound meaning. This paper presents information on the history of cisplatin and describes the molecular mechanisms of its action and the development of resistance by cancer cells. In addition, our goal was to highlight a number of therapeutic strategies to increase the effectiveness of cisplatin in the treatment of ovarian cancer, as well as to identify methods to eliminate problems associated with the use of cisplatin.

Comprehensive Two-Dimensional Gas Chromatography as a Bioanalytical Platform for Drug Discovery and Analysis

Over the last decades, comprehensive two-dimensional gas chromatography (GC×GC) has emerged as a significant separation tool for high-resolution analysis of disease-associated metabolites and pharmaceutically relevant molecules. This review highlights recent advances of GC×GC with different detection modalities for drug discovery and analysis, which ideally improve the screening and identification of disease biomarkers, as well as monitoring of therapeutic responses to treatment in complex biological matrixes. Selected recent GC×GC applications that focus on such biomarkers and metabolite profiling of the effects of drug administration are covered. In particular, the technical overview of recent GC×GC implementation with hyphenation to the key mass spectrometry (MS) technologies that provide the benefit of enhanced separation dimension analysis with MS domain differentiation is discussed. We conclude by highlighting the challenges in GC×GC for drug discovery and development with perspectives on future trends.

Effect of different molecular weight and terminal group PLGA on docetaxel nanoparticles: Characterization and cytotoxic activity of castration-resistant prostate cancer cells

The choice of polymer and its compatibility with drug used determine the fate of nanoparticle in therapy. There has been limited sources about effect of resomer differentiation in nanoparticle related with physical and chemical properties and also biological activities of product. Therefore, we aimed to formulate docetaxel loaded polylactic-co-glycolic acid nanoparticles with different molecular weights (Resomer 502 and 504) and terminal groups (Resomer 502H and 504H) and to investigate the effect of these resomers on nanoparticle character, prostate cancer and healthy cells. Docetaxel loaded PLGA nanoparticles were prepared by single emulsion solvent evaporation method. Surface characterizations were carried out by zeta sizer and scanning electron microscopy. Encapsulation efficiency, in vitro drug release profiles and cytotoxic activity were determined. Main effect on the surface morphology of nanoparticles was the molecular weight of the polymer. In groups with acid terminal function have higher encapsulation and reaction efficiency. In all formulations, in vitro release was observed after 334 hours at pH 7.4 and 240 hours at pH 5.6. Also, the groups with high molecular weight showed selective cytotoxicity. These resomers especially RG 504 and RG 504H have potential to be used as a low-dose and high-efficiency extended-release drug delivery system in the treatment of prostate cancer.

Interaction of Docetaxel with Phosphatidylcholine Membranes: A Combined Experimental and Computational Study

The antineoplastic drug Docetaxel is a second generation taxane which is used against a great variety of cancers. The drug is highly lipophilic and produces a great array of severe toxic effects that limit its therapeutic effectiveness. The study of the interaction between Docetaxel and membranes is very scarce, however, it is required in order to get clues in relation with its function, mechanism of toxicity and possibilities of new formulations. Using phosphatidylcholine biomimetic membranes, we examine the interaction of Docetaxel with the phospholipid bilayer combining an experimental study, employing a series of biophysical techniques like Differential Scanning Calorimetry, X-Ray Diffraction and Infrared Spectroscopy, and a Molecular Dynamics simulation. Our experimental results indicated that Docetaxel incorporated into DPPC bilayer perturbing the gel to liquid crystalline phase transition and giving rise to immiscibility when the amount of the drug is increased. The drug promotes the gel ripple phase, increasing the bilayer thickness in the fluid phase, and is also able to alter the hydrogen-bonding interactions in the interfacial region of the bilayer producing a dehydration effect. The results from computational simulation agree with the experimental ones and located the Docetaxel molecule forming small clusters in the region of the carbon 8 of the acyl chain palisade overlapping with the carbonyl region of the phospholipid. Our results support the idea that the anticancer drug is embedded into the phospholipid bilayer to a limited amount and produces structural perturbations which might affect the function of the membrane.

A case report on cannabinoid hyperemesis syndrome in palliative care: how good intentions can go wrong

INTRODUCTION

Synthetic cannabinoids are commonly used to manage pain, nausea, and vomiting in oncology and palliative care. Despite the current acceptance of cannabinoids as a treatment option for nausea and vomiting, there is a lack of data regarding the side effects of its prolonged use leading to possible toxicity due to accumulation, and as a result, exacerbation of nausea and vomiting rather than alleviation. Case report presentation: The patient, a 70-year-old female who was residing in the palliative care unit with the diagnosis of small-cell lung cancer. She underwent a course of chemotherapy consisting of paclitaxel, docetaxel, and cisplatin. She presented with hair loss, sore mouth, and loss of appetite, diarrhea, neuralgia, nausea and vomiting which developed approximately five hours after chemotherapy. Nabilone was used for the last five years to manage the patient's neuralgia. As her cancer progressed, dosage of nabilone was incrementally increased from 0.5 mg to 2 mg to control her pain; however, it exacerbated refractory nausea and vomiting. Nabilone was discontinued seven weeks after administration due to suspicion of cannabinoid hyperemesis syndrome. Hot baths were attempted with temporary relief. Her pain became well controlled with opioids and adjuvants and there has been no recurrence of nausea and vomiting since the cessation of nabilone.

DISCUSSION/CONCLUSION

Successful recognition and management of cannabinoid hyperemesis syndrome is especially important in individuals with co-morbid disorders in order to avoid cannabis toxicity.

Recent development of imidazole derivatives as potential anticancer agents

Cancer, one of the key health problems globally, is a group of related diseases that share a number of characteristics primarily the uncontrolled growth and invasive to surrounding tissues. Chemotherapy is one of the ways for the treatment of cancer which uses one or more anticancer agents as per chemotherapy regimen. Limitations of most anticancer drugs due to a variety of reasons such as serious side effects, drug resistance, lack of sensitivity and efficacy etc. generate the necessity towards the designing of novel anticancer lead molecules. In this regard, the synthesis of biologically active heterocyclic molecules is an appealing research area. Among heterocyclic compounds, nitrogen containing heterocyclic molecules has fascinated tremendous consideration due to broad range of pharmaceutical activity. Imidazoles, extensively present in natural products as well as synthetic molecules, have two nitrogen atoms, and are five membered heterocyclic rings. Because of their countless physiological and pharmacological characteristics, medicinal chemists are enthused to design and synthesize new imidazole derivatives with improved pharmacodynamic and pharmacokinetic properties. The aim of this present chapter is to discuss the synthesis, chemistry, pharmacological activity, and scope of imidazole-based molecules in anticancer drug development. Finally, we have discussed the current challenges and future perspectives of imidazole-based derivatives in anticancer drug development.

Development of poly (p-coumaric acid) as a self-anticancer nanocarrier for efficient and biosafe cancer therapy

Biocompatible polymers with potential therapeutic activity present an appealing strategy for the development of new functional drug carriers. In this study, we report the synthesis of therapeutic poly(p-coumaric acid) (PCA)...

Ferroptosis: A Trusted Ally in Combating Drug Resistance in Cancer

Ferroptosis, which is an iron-dependent, non-apoptotic cell death mechanism, has recently been proposed as a novel approach in cancer treatment. Bearing distinctive features and its exclusive mechanism have put forward the potential therapeutic benefit of triggering this newly discovered form of cell death. Numerous studies have indicated that apoptotic pathways are often deactivated in resistant cells, leading to a failure in therapy. Hence, alternative strategies to promote cell death are required. Mounting evidence suggests that drug-resistant cancer cells are particularly sensitive to ferroptosis. Given that cancer cells consume a higher amount of iron than healthy ones, ferroptosis not only stands as an excellent alternative to trigger cell death and reverse drug-resistance, but also provides selectivity in therapy. This review focuses specifically on overcoming drug-resistance in cancer through activating ferroptotic pathways and brings together the relevant chemotherapeutics-based and nanotherapeutics-based studies to offer a perspective for researchers regarding the potential use of this mechanism in developing novel therapeutic strategies.

Thymic Immunosuppressive Pentapeptide (TIPP) Showed Anticancer Activity in Breast Cancer and Chronic Myeloid Leukemia Both In Vitro and In Vivo

AIM

Being the common cause and major burden of deaths globally, timely management of cancer is crucial.

BACKGROUND

Thymic immunosuppressive pentapeptide (TIPP) is a novel pentapeptide originally obtained from calf thymic immunosuppressive extract. Previously, TIPP has been proved to suppress the allergic and inflammatory responses in allergic mice via blocking MAP kinases/NF-κB signaling pathways.

OBJECTIVE

In this study, in vitro anticancer activity of TIPP was tested on two different types of cancers using MCF-7 and K562 cell lines.

METHODS

Tumor xenograft models for breast cancer and chronic myeloid leukemia were designed. In vivo anticancer activity of TIPP was investigated on both cancer types. The liver and tumor tissues of the mice were preserved for immunohistochemistry analysis.

RESULTS

In vitro anticancer activity of TIPP showed significant inhibition on cell viability of both breast cancer and chronic myeloid leukemia. In vivo anticancer effect of TIPP in both types of cancer models further proved the potent anticancer nature of TIPP. Immunohistochemistry analysis assured that TIPP is a safe drug for normal organs such as the liver.

CONCLUSION

Our present study revealed that TIPP is a potent anticancer drug and an important treatment option for various diseases. Further work is needed to test the flexible and proficient activity of the novel peptide.

Efficacy and safety of nanosomal docetaxel lipid suspension based chemotherapy in metastatic ovarian carcinoma: A retrospective study

The aim of the current study was to assess the efficacy and safety of nanosomal docetaxel lipid suspension (NDLS) based chemotherapy in patients with metastatic epithelial ovarian carcinoma. In the present multicenter study, the medical records of patients who received NDLS (60-75 mg/m²; 3-weekly cycles) based chemotherapy for metastatic epithelial ovarian cancer in routine clinical care were retrospectively evaluated. Patients were followed-up from September 2014 until September 2018. The efficacy endpoints were the overall response rate (ORR) and disease control rate measured in accordance with the Response Evaluation Criteria in Solid Tumours 1.1. Overall survival (OS) and safety were also evaluated. Of the 13 patients evaluated, 46.2% (6/13) received NDLS-based first-line chemotherapy and 53.8% (7/13) patients received second-line chemotherapy [platinum-sensitive, 57.1% (4/7); platinum-resistant, 42.9% (3/7)]. The ORRs were 60.0% (3/5) and 57.1% (4/7) for patients receiving first- and second-line chemotherapy, respectively. The estimated median OS for patients receiving NDLS-based first-line chemotherapy was 17.4 months (follow-up duration, 4.3-49.4 months). The estimated median OS was 26.1 months (follow-up duration, 5.1-37.5 months) in patients with platinum-sensitive disease, whereas the OS was 14.8 months (follow-up duration, 3.5-14.8 months) in patients with platinum-resistant disease. No grade III/IV adverse events (AEs) were observed; ≥1 AE in grade I-II was reported in 84.6% (11/13) of patients. Overall, NDLS-based chemotherapy was efficacious and well-tolerated in the management of metastatic epithelial ovarian carcinoma.

An effective strategy for development of docetaxel encapsulated gold nanoformulations for treatment of prostate cancer

Nanoformulation based drug delivery is one of the most important research areas in the field of nanomedicine, which provides promising alternatives to the limitations of conventional chemotherapy. Nano drug delivery enables improved pharmacokinetic profile, bioavailability and therapeutic efficiency compared to the regular chemotherapeutic drugs. Herein, we have established a simple method for the synthesis of docetaxel (Dtx) encapsulated poly (ethylene glycol) (PEG) functionalized gold nanoparticles (AuNPs) for targeted drug delivery to prostate cancer. AuNPs were synthesized by the citrate ion reduction method followed by functionalization with thiol-PEG-amine (SH-PEG-NH2). SH-PEG-NH2 functionalized AuNPs were conjugated with the targeting vehicle, folic acid (FA). The anticancer drug, Dtx was encapsulated within AuNPs by the non-covalent linkage method. The physicochemical characteristics of the synthesized nanoformulations were extensively characterized by various spectral and microscopic studies. HR-TEM indicates the average size of the AuNPs is 16 nm and the nanoformulations is 18 nm. The encapsulation efficiency of the Dtx is ~ 96% which is confirmed by the elemental mapping analysis. The in vitro drug release profile of Dtx and AuNPs nanoformulations were studied by the dialysis membrane method. The anticancer activity of docetaxel encapsulated AuNPs were evaluated with prostate cancer cell lines (PC3). The drug encapsulated nanoformulations reduced the cell viability to about 40% (40 µM concentration at 24, 48 and 72 h of treatment). The optical microscopy observation reveals that the damage of prostate cancer cells after exposure to Dtx encapsulated AuNPs. The good cytotoxic activity of the present nanoformulation against prostate cancer cell lines enables its application for targeted drug delivery to prostate cancer.

Novel Vitamin E TPGS based docetaxel nanovesicle formulation for its safe and effective parenteral delivery: Toxicological, pharmacokinetic and pharmacodynamic evaluation

Docetaxel (DTX) is a highly lipophilic, BCS class IV drug with poor aqueous solubility (12.7 µg/mL). Presently, only injectable formulation is available in the market which uses a large amount of surfactant (Tween 80) and dehydrated alcohol as a solubilizer. High concentrations of Tween 80 in injectable formulations are associated with severe consequences i.e. nephrotoxicity, fluid retention, and hypersensitivity reactions. The present study aims to eliminate Tween 80, thus novel biocompatible surfactant Vitamin E TPGS based nanovesicle formulation of DTX (20 mg/mL) was developed and evaluated for different quality control parameters. Optimized nanovesicular formulation (NV-TPGS-3) showed nanometric size (102.9 ± 2.9 nm), spherical vesicular shape, high drug encapsulation efficiency (95.2 ± 0.5%), sustained-release profile and high dilution integrity with normal saline. In vitro cytotoxicity assay, showed threefold elevation in the IC₅₀ value of the optimized formulation in comparison to the commercial formulation. Further, no mortality and toxicity were observed during 28 days repeated dose sub-acute toxicity studies in Swiss albino mice up to the dose of 138 mg/kg, whereas, commercial formulation showed toxicity at 40 mg/kg. In addition, in vivo anticancer activity on Ehrlich Ascites Carcinoma induced mice showed a significant tumour growth inhibition of 76.3 ± 5.3% with the NV-TPGS-3 treatment when compared to Ehrlich Ascites Carcinoma control. Results demonstrated that the developed Vitamin E TPGS based nanovesicular formulation of DTX could be a better alternative to increase its clinical uses with improved therapeutic efficacy, reduced toxicity and dosing frequency, and sustained drug release behaviour.

Treatment algorithm in patients with ovarian cancer

Most ovarian cancer patients are diagnosed only at advanced stages when survival outcomes are worse, andwhen therapeutic decisions might prove challenging. The fundamental treatment for women with ovarian cancerincludes debulking surgery whenever possible and appropriate systemic therapy (chemotherapy, targeted andantiangiogenic agents). In the last few years, knowledge about histological and molecular characteristics of ovariancancer subtypes and stages has increased considerably. This has enabled the development and improvement ofseveral options for the diagnosis and treatment of ovarian cancer in a patient-tailored approach. Accordingly,therapeutic decisions are guided by the characteristics of the patient and the tumour, especially the molecularfeatures of the cancer subtype and disease stage. Particularly relevant are the advances in early genetic testing ofgermline and somatic mutations involved in DNA repair, and the clinical development of targeted agents. In orderto implement the best individual medical strategies, in this article, we present an algorithm of treatment options,including recently developed targeted agents, for primary and recurrent ovarian cancer patients in Belgium.

Overview of imaging findings associated with systemic therapies in advanced epithelial ovarian cancer

PURPOSE

To provide an overview for radiologists of the systemic agents used in the treatment of advanced epithelial ovarian cancer (EOC) and their associated toxicities.

RESULTS

EOC is a common gynecological malignancy, with the majority of patients presenting with advanced stage disease at the time of diagnosis. Although primary cytoreductive surgery and chemotherapy are the principal treatments for EOC, recurrence rates of disease remain high. As several molecular targeted therapies have been developed in the last decade, various novel agents have shown efficacy in the treatment of advanced EOC. Advanced EOC will be discussed by outlining the relevant radiological features of toxicities.

CONCLUSION

Knowledge of the systemic therapies utilized in the treatment of advanced EOC and their associated radiological features is critical in diagnostic image interpretation.

Selective Intratumoral Drug Release and Simultaneous Inhibition of Oxidative Stress by a Highly Reductive Nanosystem and Its Application as an Anti-tumor Agent

Excessive oxidative stress is always associated with the serious side effects of chemotherapy. In the current study, we developed a vitamin E based strongly reductive nanosystem to increase the loading efficiency of docetaxel (DTX, DTX-VNS), reduce its side toxicity and enhance the antitumor effect. Methods: We used Förster Resonance Energy Transfer (FRET) to reveal the in vivo and in vitro fate of DTX-VNS over time. All FRET images were observed using the Maestro imaging system (CRI, Inc., Woburn, MA) and Fluo-View software (Olympus LX83-FV3000). Results: Through FRET analyzing, we found that our nanosystem showed a selective rapider release of drugs in tumors compared to normal organs due to the higher levels of ROS in tumor cells than normal cells, and the accumulation of DTX at tumor sites in the DTX-VNS group was also notably more than that in the Taxotere group after 24 h injection. Meanwhile, DTX-VNS had a prominently stronger anti-tumor effect in various models than Taxotere, and had a synergistic effect of immunotherapy. Conclusions: Our work presented a useful reference for clinical exploration of the in vivo behavior of nanocarriers (DTX-VNS), inhibition oxidative stress and selective release of drugs at tumor sites, thus reducing the side effects and enhancing the anti-tumor effects.

In Search of Panacea-Review of Recent Studies Concerning Nature-Derived Anticancer Agents

Cancers are one of the leading causes of deaths affecting millions of people around the world, therefore they are currently a major public health problem. The treatment of cancer is based on surgical resection, radiotherapy, chemotherapy or immunotherapy, much of which is often insufficient and cause serious, burdensome and undesirable side effects. For many years, assorted secondary metabolites derived from plants have been used as antitumor agents. Recently, researchers have discovered a large number of new natural substances which can effectively interfere with cancer cells’ metabolism. The most famous groups of these compounds are topoisomerase and mitotic inhibitors. The aim of the latest research is to characterize natural compounds found in many common foods, especially by means of their abilities to regulate cell cycle, growth and differentiation, as well as epigenetic modulation. In this paper, we focus on a review of recent discoveries regarding nature-derived anticancer agents.

Protein Corona over Mesoporous Silica Nanoparticles: Influence of the Pore Diameter on Competitive Adsorption and Application to Prostate Cancer Diagnostics

Diagnostic tests based on proteomics analysis can have significant advantages over more traditional biochemical tests. However, low molecular weight (MW) protein biomarkers are difficult to identify by standard mass spectrometric analysis, as they are usually present at low concentrations and are masked by more abundant resident proteins. We have previously shown that mesoporous silica nanoparticles are able to capture a predominantly low MW protein fraction from the serum, as compared to the protein corona (PC) adsorbed onto dense silica nanoparticles. In this study, we begin by further investigating this effect using liquid chromatography-mass spectrometry (LC-MS)/MS and thermogravimetric analysis (TGA) to compare the MW of the proteins in the coronas of mesoporous silica nanoparticles with the same particle size but different pore diameters. Next, we examine the process by which two proteins, one small and one large, adsorb onto these mesoporous silica nanoparticles to establish a theory of why the corona becomes enriched in low MW proteins. Finally, we use this information to develop a novel system for the diagnosis of prostate cancer. An elastic net statistical model was applied to LC-MS/MS protein coronas from the serum of 22 cancer patients, identifying proteins specific to each patient group. These studies help to explain why low MW proteins predominate in the coronas of mesoporous silica nanoparticles, and they illustrate the ability of this information to supplement more traditional diagnostic tests.

Depletion of tumor-associated macrophages enhances the anti-tumor effect of docetaxel in a murine epithelial ovarian cancer

Docetaxel (DTXL), a new member of the taxoid family, has been used for cancer treatment. However, increasing cases of DTXL resistance have been reported. Tumor-associated macrophages (TAMs) have been implicated in tumor invasion and chemo-resistance. Eliminating TAMs by inhibiting colony stimulating factor-1 receptor (CSF-1R) has emerged as a promising strategy for cancer treatment. BLZ945 is a CSF-1R inhibitor and has anti-tumor function. In present study, anti-tumor effects of combination treatment of BLZ945 and DTXL were investigated. We established a mouse ovarian cancer model and investigated the effect of BLZ945, DTXL single treatment or combination treatment on TAMs infiltration, tumor growth, CD8⁺ T cell infiltration and cancer metastasis. DTXL treatment increased the infiltration while BLZ945 induced cell apoptosis in macrophages. DTXL/BLZ945 combination treatment significantly inhibited tumor growth, reduced the abundance of TAMs, increased CD8⁺ T cell infiltration and prevented lung metastasis. Depletion of Tumor-Associated Macrophages (TAMs) by BLZ945 enhanced the anti-tumor effect of DTXL in a murine epithelial ovarian cancer.

Current advances in development of new docetaxel formulations

INTRODUCTION

Docetaxel (DTX) is one of the most important chemotherapeutic agents and has been widely used for treatment of various types of cancers. However, the clinical chemotherapy of DTX gives many undesirable side effects due to the usage of organic solvent in the injection and its low selectivity for tumor cells. With the evolution of pharmaceutical technologies, great efforts have been paid to develop new DTX formulations to overcome these problems.

AREAS COVERED

This review provided an overview of the preparation and activities of new DTX formulations, which were classified by administration methods, including injection, oral, transdermal and rectal administration. Besides, up to date information of the clinical status of new DTX formulations was summarized. We also discussed the challenges and perspectives of the future development of DTX formulations.

EXPERT OPINION

There have been numerous studies on new DTX-based formulations in recent years, and many of them exhibited significantly enhanced anti-tumor and targeting activity compared with DTX in preclinical studies. However, only a few entered clinical trials, and none has been approved into market. The clinical translation of experimental drug faces many hurdles, including the limited knowledge of nanomedicine and oncology, safety issues, controllable and reproducible production.

Anticancer Activity of Natural Compounds from Plant and Marine Environment

This paper describes the substances of plant and marine origin that have anticancer properties. The chemical structure of the molecules of these substances, their properties, mechanisms of action, their structure⁻activity relationships, along with their anticancer properties and their potential as chemotherapeutic drugs are discussed in this paper. This paper presents natural substances from plants, animals, and their aquatic environments. These substances include the vinca alkaloids, mistletoe plant extracts, podophyllotoxin derivatives, taxanes, camptothecin, combretastatin, and others including geniposide, colchicine, artesunate, homoharringtonine, salvicine, ellipticine, roscovitine, maytanasin, tapsigargin, and bruceantin. Compounds (psammaplin, didemnin, dolastin, ecteinascidin, and halichondrin) isolated from the marine plants and animals such as microalgae, cyanobacteria, heterotrophic bacteria, invertebrates (e.g., sponges, tunicates, and soft corals) as well as certain other substances that have been tested on cells and experimental animals and used in human chemotherapy.

Imidazoles as potential anticancer agents

Cancer is a black spot on the face of humanity in this era of science and technology. Presently, several classes of anticancer drugs are available in the market, but issues such as toxicity, low efficacy and solubility have decreased the overall therapeutic indices. Thus, the search for new promising anticancer agents continues, and the battle against cancer is far from over. Imidazole is an aromatic diazole and alkaloid with anticancer properties. There is considerable interest among scientists in developing imidazoles as safe alternatives to anticancer chemotherapy. The present article describes the structural, chemical, and biological features of imidazoles. Several classes of imidazoles as anticancer agents based on their mode of action have been critically discussed. A careful observation has been made into pharmacologically active imidazoles with better or equal therapeutic effects compared to well-known imidazole-based anticancer drugs, which are available on the market. A brief discussion of the toxicities of imidazoles has been made. Finally, the current challenges and future perspectives of imidazole based anticancer drug development are conferred.

Docetaxel inhibits the proliferation of non-small-cell lung cancer cells via upregulation of microRNA-7 expression

Lung cancer is the leading cause of cancer-related deaths worldwide and about 85% of these are non-small cell lung cancer (NSCLC). Several new chemotherapeutic agents have recently shown encouraging activity in NSCLC, especially docetaxel. MiRNAs (MicroRNAs) are closely related to cancer development. We studied miRNAs in NSCLC cell lines to identify those that can regulate and predict the effectiveness of docetaxel on NSCLC. CCK8, Annexin and V-FITC assays were carried out to evaluate the inhibitory effect of docetaxel on NSCLC cell lines A549 and H460, and qRT-PCR was used to detect and compare six miRNAs expression levels in the two cells with docetaxel or not. Knockdown of miR-7 by RNA interference and overexpression of miR-7 were taken to evaluate the effect of miR-7 on docetaxel effectiveness. Western blotting was used to evaluate the effect of miR-7 on Bcl2 in A549 and H460 cells. Docetaxel induced non-small cell lung cancer cell apoptosis and suppressed cell proliferation in vitro. MiR-7 expression levels were increased by docetaxel in the two cell lines. MiR-7 overexpression improved anti-proliferative and pro-apoptotic effects of docetaxel on the NSCLC cells and that miR-7 down-regulation decreased those effects. Moreover, subsequent experiments showed that BCL-2 was downregulated by miR-7 at both transcriptional and translational levels. This study further extends the biological role of miR-7 in NSCLC A549 and H460 cells and identifies BCL-2 as a novel target possibly involved in miR-7-mediated growth suppression and apoptosis induction of NSCLC cells.

Docetaxel-loaded solid lipid nanoparticles suppress breast cancer cells growth with reduced myelosuppression toxicity

Docetaxel is an adjuvant chemotherapy drug widely used to treat multiple solid tumors; however, its toxicity and side effects limit its clinical efficacy. Herein, docetaxel-loaded solid lipid nanoparticles (DSNs) were developed to reduce systemic toxicity of docetaxel while still keeping its anticancer activity. To evaluate its anticancer activity and toxicity, and to understand the molecular mechanisms of DSNs, different cellular, molecular, and whole genome transcription analysis approaches were utilized. The DSNs showed lower cytotoxicity compared with the commercial formulation of docetaxel (Taxotere^®) and induced more apoptosis at 24 hours after treatment in vitro. DSNs can cause the treated cancer cells to arrest in the G2/M phase in a dose-dependent manner similar to Taxotere. They can also suppress tumor growth very effectively in a mice model with human xenograft breast cancer. Systemic analysis of gene expression profiles by microarray and subsequent verification experiments suggested that both DSNs and Taxotere regulate gene expression and gene function, including DNA replication, DNA damage response, cell proliferation, apoptosis, and cell cycle regulation. Some of these genes expressed differentially at the protein level although their messenger RNA expression level was similar under Taxotere and DSN treatment. Moreover, DSNs improved the main side effect of Taxotere by greatly lowering myelosuppression toxicity to bone marrow cells from mice. Taken together, these results expound the antitumor efficacy and the potential working mechanisms of DSNs in its anticancer activity and toxicity, which provide a theoretical foundation to develop and apply a more efficient docetaxel formulation to treat cancer patients.

Functional p53 determines docetaxel sensitivity in prostate cancer cells

BACKGROUND

Docetaxel is the first line treatment for castration resistant prostate cancer (CRPC). However, docetaxel resistance rapidly develops. Identifying the critical mechanisms giving rise to docetaxel resistance is the major challenge in advanced prostate cancer.

METHODS

The effects of docetaxel on human DU145, PC3, LNCaP, and C4-2 prostate cancer cells were examined in cell culture, and p53 expression were analyzed by Western blot analysis. The potential role of p53 in docetaxel sensitivity in prostate cancer cells was tested by either p53 silencing using shRNA or p53 overexpression by introducing wild-type p53.

RESULTS

We found that DU145 (mutant p53) and PC3 (p53 null) cells were less sensitive than LNCaP and C4-2 cells expressing functional p53 in response to docetaxel. Docetaxel treatment induces considerably higher apoptosis in LNCaP and C4-2 cells than in DU145 and PC3 cells in a dose dependent manner. Docetaxel increases the levels of ser15 phosphorylation of p53 in a dose dependent manner in both LNCaP and C4-2 cells, while has no effect on the levels of ser15 phosphorylation of p53 in DU145 cells. These results suggest that p53 phosphorylation is associated with docetaxel sensitivity in prostate cancer cells. To further confirm whether p53 activation can induce cell sensitivity to docetaxel treatment, we used p53 shRNA to knock down p53 expression in C4-2 cells and determined the cells response to docetaxel treatment. Knockdown of p53 significantly down regulated p53 phosphorylation and blocked docetaxel induced apoptotic cell death compared to the vector control. To further confirm this observation, we established a stable knock out p53 in C4-2 cells. Down regulation of p53 in the stable p53 knock out C4-2 cells significantly inhibited docetaxel induced apoptotic cell death. We also used wild-type (WT) p53 to over express p53 in DU145 cells, and found that expression of WT-p53 in DU145 cells increased their sensitivity to docetaxel.

CONCLUSIONS

These results demonstrate that docetaxel induces p53 phosphorylation and that p53 status is a crucial determinant of docetaxel sensitivity in prostate cancer cells.

A study of docetaxel weekly or every three weeks in combination with carboplatin as first line chemotherapy in epithelial ovarian cancer: Hematological and non-hematological toxicity profiles

The purpose of this study was to compare the toxicity profiles of docetaxel administered on a weekly schedule and the standard three-week schedule in the treatment of advanced primary ovarian carcinoma. Eligible patients were treated with intravenous docetaxel (30 mg/m²) on days 1, 8 and 15, and carboplatin (AUC 5) on day 1 or with docetaxel (75 mg/m²) and carboplatin (AUC 5) on day 1; Q21 days for 6 cycles. This study was a pooled study of two primary phase II studies. A total of 108 patients received the weekly schedule and 59 patients received the three-week schedule. All patients were evaluated for toxicity. The overall response rate was 79% and the biochemical response 93% for the weekly schedule. The median overall survival rate was 35.3 months. Neutropenia was significantly more common (ANOVA; p<0.0001) in the three-week group than in the weekly group during all six courses of chemotherapy. Fever and infections were also more common in this group. Thrombocytopenia and anemia were slightly more common in the weekly group. Fatigue, epiphora, nail changes and taste disturbances were specific side-effects following weekly docetaxel. Peripheral sensory neuropathy (grade 1–2) increased with every cycle of treatment, but in a similar manner in the two groups. Grade 3–4 neuropathy was not recorded. Oral mucositis and myalgia were two side-effects associated with the three-week schedule. Nausea and vomiting, diarrhea and dyspnea were a limited problem in both groups. Cardiac toxicity was rare and did not differ between the two docetaxel schedules. The weekly administration was favored due to the lower rates of neutropenia, fever, infections, oral mucositis and myalgia. However, epiphora and nail changes were specific side-effects of the weekly treatment. Both regimens appeared to be rather well tolerated with similar compliance (66 and 70%) with regard to completion of the planned six courses of chemotherapy.

Phase II study of docetaxel weekly in combination with carboplatin every 3 weeks as first-line chemotherapy in stage IIB to stage IV epithelial ovarian cancer

OBJECTIVES

The purpose of this study was to assess the response rate, toxicity, progression-free survival, and overall survival in a series of patients with advanced-stage ovarian carcinoma treated with a first-line weekly docetaxel and 3 weekly carboplatin regimen.

METHODS

All eligible patients were treated with intravenous docetaxel (30 mg/m) on days 1, 8, and 15, and carboplatin (area under the curve, 5) on day 1; every 21 days for at least 6 cycles.

RESULTS

One hundred six patients received at least one cycle of primary chemotherapy (median, 6.0; range, 1-9), and they were evaluable for toxicity assessment. Eighty-five patients had evaluable (measurable) disease and received at least 3 courses of chemotherapy and were evaluable for clinical response rate. The overall response rate was 78.8% (95% confidence interval, 70.1%-87.5%), and the biochemical response 92.8% (95% confidence interval, 87.2%-98.4%). The median progression-free survival was 12.0 months and the median overall survival was 35.3 months. Thirty-six patients (34.0%) experienced grades 3 and 4 neutropenia, which resulted in the removal of 3 patients. Six patients (5.7%) experienced grades 3 or 4 thrombocytopenia. No patients experienced grade 3 to grade 4 sensory neuropathy. Epiphora, nail changes, and fatigue were frequently recorded nonhematologic adverse effects.

CONCLUSIONS

The tolerable hematologic toxicity (no need for colony-stimulating factors) and the low rate of neurotoxicity (only grades 1-2) and response rates in line with the standard 3-week paclitaxel-carboplatin regimen for advanced primary ovarian carcinoma after suboptimal cytoreductive surgery make this regimen an interesting alternative in selected patients.

Comparison of active and passive targeting of docetaxel for prostate cancer therapy by HPMA copolymer-RGDfK conjugates

N-(2-Hydroxypropyl)methacrylamide (HPMA) copolymer-docetaxel-RGDfK conjugate was synthesized, characterized, and evaluated in vitro and in vivo in comparison with untargeted low and high molecular weight HPMA copolymer-docetaxel conjugates. The targeted conjugate was designed to have a hydrodynamic diameter below renal threshold to allow elimination post treatment. All conjugates demonstrated the ability to inhibit the growth of DU145 and PC3 human prostate cancer cells and the HUVEC at low nanomolar concentrations. The targeted conjugate showed active binding to α(v)β(3) integrins in both HUVEC and DU145 cells, whereas the untargeted conjugate demonstrated no evidence of specific binding. Efficacy at two concentrations (20 mg/kg and 40 mg/kg) was evaluated in nu/nu mice bearing DU145 tumor xenografts treated with a single dose of conjugates and compared with controls. RGDfK targeted and high molecular weight nontargeted conjugates exhibited the highest antitumor efficacy as evaluated by tumor regression. These results demonstrate that α(v)β(3) integrin targeted polymeric conjugates with improved water solubility, reduced toxicity and ease of elimination post treatment in vivo are promising candidates for prostate cancer therapy.

Second generation benzofuranone ring substituted noscapine analogs: synthesis and biological evaluation

Microtubules, composed of α/β tubulin heterodimers, represent a validated target for cancer chemotherapy. Thus, tubulin- and microtubule-binding antimitotic drugs such as taxanes and vincas are widely employed for the chemotherapeutic management of various malignancies. Although quite successful in the clinic, these drugs are associated with severe toxicity and drug resistance problems. Noscapinoids represent an emerging class of microtubule-modulating anticancer agents based upon the parent molecule noscapine, a naturally occurring non-toxic cough-suppressant opium alkaloid. Here we report in silico molecular modeling, chemical synthesis and biological evaluation of novel analogs derived by modification at position-7 of the benzofuranone ring system of noscapine. The synthesized analogs were evaluated for their tubulin polymerization activity and their biological activity was examined by their antiproliferative potential using representative cancer cell lines from varying tissue-origin [A549 (lung), CEM (lymphoma), MIA PaCa-2 (pancreatic), MCF-7 (breast) and PC-3 (prostate)]. Cell-cycle studies were performed to explore their ability to halt the cell-cycle and induce subsequent apoptosis. The varying biological activity of these analogs that differ in the nature and bulk of substituent at position-7 was rationalized utilizing predictive in silico molecular modeling.

Clinical and biological impact of EphA2 overexpression and angiogenesis in endometrial cancer

OBJECTIVE

EphA2 overexpression predicts poor prognosis in endometrial cancer. To explore mechanisms for this association and assess its potential as therapeutic target, the relationship of EphA2 expression to markers of angiogenesis was examined using patient samples and an orthotopic mouse model of uterine cancer.

EXPERIMENTAL DESIGN

Expression of EphA2, estrogen receptor (ER), progesterone receptor (PR), Ki-67, vascular endothelial growth factor (VEGF) and microvessel density (MVD) was evaluated using immunohistochemistry in 85 endometrioid endometrial adenocarcinomas (EEC) by two independent investigators. Results were correlated with clinicopathological characteristics. The effect of EphA2- agonist monoclonal antibody EA5, alone or in combination with docetaxel was studied in vitro and in vivo. Samples were analyzed for markers of angiogenesis, proliferation and apoptosis.

RESULTS

Of 85 EEC samples, EphA2 was overexpressed in 47% of tumors and was significantly associated with high VEGF expression (p=0.001) and high MVD counts (p=0.02). High EphA2 expression, high VEGF expression and high MVD counts were significantly associated with shorter disease-specific survival. EA5 led to decrease in EphA2 expression and phosphorylation in vitro. In the murine model, while EA5 (33-88%) and docetaxel (23-55%) individually led to tumor inhibition over controls, combination therapy had the greatest efficacy (78-92%, p.

Synthesis and biological evaluation of 2-amino-1-thiazolyl imidazoles as orally active anticancer agents

Designed from a high throughput screened hit compound, novel 2-amino-1-thiazolyl imidazoles were synthesized and demonstrated cytotoxicity against human cancer cells. 1-(4-Phenylthiazol-2-yl)-4-(thiophen-2-yl)-1H-imidazol-2-amine (compound 2), a 2-amino-1-thiazolyl imidazole, inhibited tubulin polymerization, interacted with the colchicine-binding sites of tubulins, and caused cell cycle arrest at the G(2)/M phase in human gastric cancer cells. Disruption of the microtubule structure in cancer cells by compound 2 was also observed. Compound 2 concentration-dependently inhibited the proliferation of cancer cells in histocultured human gastric and colorectal tumors. Given orally, compound 2 prolonged the lifespans of leukemia mice intraperitoneally inoculated with the murine P388 leukemic cells. We report 2-amino-1-thiazolyl imidazoles as a novel class of orally active microtubule-destabilizing anticancer agents.

Combination of docetaxel and recombinant vaccine enhances T-cell responses and antitumor activity: effects of docetaxel on immune enhancement

PURPOSE

Taxanes comprise some of the most widely used cancer chemotherapeutic agents. Members of this drug family, including docetaxel, are commonly used to treat breast, prostate, and lung cancers, among others. This study was designed to determine if this taxane has the ability to modulate components of the immune system independent of antitumor activity and to investigate the potential synergistic activities of the combination of docetaxel and vaccine therapy.

EXPERIMENTAL DESIGN

We examined the in vivo effects of docetaxel on immune-cell subsets and on the function of CD4+, CD8+, and regulatory T-cell (Treg) populations in response to antigen-specific vaccination. We also examined the antitumor effects of the combination of docetaxel and vaccine in a preclinical model in which docetaxel has no observable effect on tumor growth.

RESULTS

These studies show for the first time that (a) docetaxel modulates CD4+, CD8+, CD19+, natural killer cell, and Treg populations in non-tumor-bearing mice; (b) unlike cyclophosphamide, docetaxel does not inhibit the function of Tregs; (c) docetaxel enhances CD8+ but not CD4+ response to CD3 cross-linking; (d) docetaxel given after vaccination provides optimal enhancement of immune response to recombinant viral vaccines; (e) docetaxel combined with recombinant viral vaccine is superior to either agent alone at reducing tumor burden; and (f) docetaxel plus vaccine increases antigen-specific T-cell responses to antigen in the vaccine, as well as to cascade antigens derived from the tumor.

CONCLUSIONS

These findings suggest potential clinical benefit for the combined use of docetaxel and recombinant cancer vaccines.

Discordance of clinical symptoms and electrophysiologic findings in taxane plus platinum-induced neuropathy

Paclitaxel combined with carboplatin is currently accepted as the first-line treatment for ovarian carcinoma, frequently associated with neuropathy. Due to its frequent association with neuropathy, combination of docetaxel and carboplatin has been suggested as an alternative. A 47-year-old woman developed paresthesia after the first cycle of paclitaxel/carboplatin for ovarian cancer. Her nerve conduction study (NCS) showed only sural neuropathy after completion of six cycles, which returned to normal in 6 months. She had fewer neuropathy symptoms when treatment was changed to docetaxel/carboplatin for recurrent cancer. NCS revealed generalized sensory neuropathy following docetaxel/carboplatin treatment, which normalized after 12 months. Our observation indicated that there is a disparity between clinical symptoms and electrophysiologic examination in taxane-induced neuropathy. Although docetaxel was tolerated well by the patient, evidence of generalized sensory neuropathy was present in NCS.

The anti-tumor efficacy of a GM-CSF-secreting tumor cell vaccine is not inhibited by docetaxel administration

Docetaxel has demonstrated therapeutic efficacy against breast, prostate, and ovarian cancer and other solid tumors. The tumoricidal activity of docetaxel is mainly attributed to its ability to block microtubule depolymerization, thus inducing G(2)-M arrest and apoptosis. Mounting evidence indicates that docetaxel also possesses immunomodulatory activity such as augmenting macrophage and lymphokine activated killer activity and inducing pro-inflammatory cytokines, suggesting that docetaxel may be a good chemotherapeutic agent to combine with cancer immunotherapies, assuming that it does not inhibit the vaccine-induced immune response. The anti-tumor activity of the combination of docetaxel and a GM-CSF-secreting B16F10 tumor cell vaccine (B16.GM) was evaluated in the murine B16 melanoma model. Dose levels of docetaxel and the B16.GM vaccine known to be ineffective when used as single agents were selected. Three iv treatments of 6 mg/kg docetaxel per injection given on days 5, 9, and 13 after tumor challenge or a single vaccination with 2-3 x 10(6) B16.GM cells on day 3 were ineffective at inhibiting tumor growth when used as single agents [median survival time (MST)=24 days in both treatment groups and in control animals]. However, combination of docetaxel and B16.GM vaccine significantly delayed tumor growth, increasing MST to 45 days. A similar improvement in anti-tumor efficacy was observed using multiple treatment cycles of the B16.GM vaccine/docetaxel combination. Administration of docetaxel every 4 days between bi-weekly B16.GM vaccinations increased the median survival of tumor-bearing mice from 31 to 52 days compared to multiple B16.GM vaccinations alone. In summary, these data demonstrate that rather than inhibiting the anti-tumor effects of a GM-CSF-secreting tumor cell vaccine, docetaxel combined with a whole cell vaccine significantly inhibits tumor growth, increases survival time and does not impede T-cell activation in the murine B16F10 melanoma tumor model. GM-secreting tumor cell vaccines in combination with docetaxel may represent a new strategy for combining chemo and immunotherapy for cancer.

Novel mechanisms of platinum drug resistance identified in cells selected for resistance to JM118 the active metabolite of satraplatin

PURPOSE

The goal of this study was to identify molecular determinants of sensitivity and resistance to JM118, the active metabolite of satraplatin, an orally bioavailable cisplatin analog that has activity in prostate cancer.

EXPERIMENTAL DESIGN

Human ovarian carcinoma 2008/JM118 cells were derived from parental 2008 cells by repeated exposure to JM118; the revertant 2008/JM118/REV subline was isolated from the 2008/JM118 cells by growth in the absence of drug. Drug sensitivity was determined by clonogenic assay and Pt levels were measured by ICP-MS.

RESULTS

Eight sequential rounds of selection yielded the 2008/JM118 subline that was 4.9-fold resistant to JM118 and cross-resistant at varying levels to satraplatin, cisplatin, carboplatin, and oxaliplatin. Cross-resistance to the other Pt drugs was lost as resistance to JM118 waned. The same parental 2008 cells selected for resistance to cisplatin were partially cross-resistant to JM118. The 2008/JM118 cells accumulated significantly more Pt than the 2008 cells when exposed to low concentrations of either JM118 or cisplatin indicating a detoxification process that involves intracellular sequestration. In contrast, 2008 cells selected for cisplatin resistance accumulated less cisplatin and less JM118 reflecting a mechanism involving reduced accumulation. The 2008 and 2008/JM118 cells did not differ in their uptake or efflux of 64Cu, expression of Cu efflux transporters ATP7A or ATP7B or their glutathione content. The 2008/JM118 cells exhibited 3.0-7.7-fold hypersensitivity to docetaxel, paclitaxel and doxorubicin. Expression profiling identified 4 genes that were significantly up-regulated and 19 that were down-regulated in the 2008/JM118 cells at a false discovery rate of 1 gene.

CONCLUSIONS

While the cellular defense mechanisms that protect cells against JM118 also mediate resistance to the other Pt drugs, these mechanisms are quite different from those commonly found in cells selected for resistance to cisplatin. JM118-resistant cells accumulate more rather than less Pt and rely on an intracellular detoxification mechanism different from that involved in cisplatin resistance. This is consistent with clinical evidence suggesting that satraplatin has activity in diseases in which cisplatin does not. In this model, JM118 resistance is associated with substantial collateral hypersensitivity to docetaxel, paclitaxel, and doxorubicin.