Taxanes as first-line therapy for advanced non-small cell lung cancer: a systematic review and practice guideline

Healthcare Resource Utilization and Associated Costs among Patients with Advanced Non-Small-Cell Lung Cancer Receiving Chemotherapy or Immunotherapy in Spain: A Single-Center, Real-World, Exploratory Study

The objective of this observational, single-center, retrospective study conducted in a Spanish tertiary hospital was to describe the real-world (RW) healthcare resource utilization (HCRU) among patients with advanced non-small-cell lung cancer (aNSCLC) who received chemotherapy (CT) or immunotherapy (IT) as first and second lines of treatment. A total of 173 patients diagnosed with aNSCLC and treated between January 2016 and August 2020 were included. The standardized average costs per patient/year were EUR 40,973.2 and EUR 22,502.4 for first-line CT and IT and EUR 140,601.3 and EUR 20,175.9 for second-line CT and IT, respectively. The average annual costs per patient associated with adverse-event (AE) onset were EUR 29,939.7 and EUR 460.7 for first-line CT and IT and EUR 35,906.4 and EUR 3206.1 for second-line CT and IT, respectively. The costs associated with disease management were EUR 33,178.0 and EUR 22,448.4 for first-line CT and IT and EUR 127,134.2 and EUR 19,663.9 for second-line CT and IT, respectively. In conclusion, IT use showed a lower average annual cost per patient, which was associated with lower HCRU for both disease and AE management, compared to the use of CT. However, these results should be further confirmed in the context of the currently implemented treatment schemes, including the combination of CT with single or dual IT.

Clinical efficacy and safety of Chinese herbal injections in combination with platinum-based chemotherapy for advanced non-small cell lung cancer: a systematic review and meta-analysis of 140 randomized controlled trials

Background and aim

Chinese herbal injection (CHI) is a widely used preparation for advanced non-small cell lung cancer (NSCLC) treatment to alleviate the adverse drug reactions and enhance the clinical efficacy of chemotherapy. However, its efficacy and safety in combination with platinum-based chemotherapy (PBC) remain poorly understood owing to the lack of high-level evidence in the face of a wide variety of CHIs. Therefore, in this study, we aimed to explore the efficacy and safety of CHIs in combination with PBC regimens in the treatment of mid- and advanced NSCLC.

Methods

Systematic evaluation and meta-analysis were conducted as per the Preferred Reporting Project for Systematic Evaluation and Meta-Analysis Protocols (PRISMA-P). Seven databases were comprehensively searched for relevant randomized controlled trials (RCTs) through August 1, 2022. The quality of each study was evaluated based on the Cochrane Handbook for Systematic Reviews of Interventions. Statistical analysis was performed using Revman 5.3, with dichotomies expressed as risk ratio (RR) and 95% confidence interval (CI). Objective response rate (ORR) and disease control rate (DCR) were selected as the primary outcomes, with quality of life (QoL) and toxic side effects as secondary outcomes.

Results

A total of 140 RCTs were included in this study. The results of the meta-analysis suggested that, compared with PBC alone, PBC combined with CHIs significantly improved the ORR (RR=1.35, 95% CI: 1.30-1.41, P<0.001), DCR (RR=1.15, 95% CI: 1.13-1.18, P<0.001) and QoL (RR=1.29, 95% CI: 1.24-1.33, P<0.001). Moreover, the combination treatment reduced chemotherapy-induced leukopenia (RR=0.69, 95% CI: 0.64-0.75, P<0.001), anemia (RR=0.70, 95% CI: 0.62-0.79, P<0.001), thrombocytopenia (RR=0.68, 95% CI: 0.62-0.75, P<0.001), nausea and vomiting (RR=0.69, 95% CI: 0.63-0.76, P<0.001), diarrhea (RR=0.59, 95% CI: 0.48-0.73, P<0.001), and constipation (RR=0.68, 95% CI: 0.54-0.86, P=0.001).

Conclusion

According to the available evidence, CHIs in combination with PBC can improve clinical efficacy and reduce the toxic side effects in the treatment of advanced NSCLC. However, considering the study's limitations, more rigorous and high-quality studies are needed to further confirm the results.

Systematic review registration

https://inplasy.com/inplasy-2022-1-0104/, identifier INPLASY202210104.

Recent progress in drug delivery systems for tyrosine kinase inhibitors in the treatment of lung cancer

Lung cancer ranks as the second most commonly diagnosed cancer in both men and women worldwide. Despite the availability of diverse diagnostic and treatment strategies, it remains the leading cause of cancer-related deaths globally. The current treatment approaches for lung cancer involve the utilization of first generation (e.g., erlotinib, gefitinib) and second generation (e.g., afatinib) tyrosine kinase inhibitors (TKIs). These TKIs exert their effects by inhibiting a crucial enzyme called tyrosine kinase, which is responsible for cell survival signaling. However, their clinical effectiveness is hindered by limited solubility and oral bioavailability. Nanotechnology has emerged as a significant application in modern cancer therapy. Nanoparticle-based drug delivery systems, including lipid, polymeric, hybrid, inorganic, dendrimer, and micellar nanoparticles, have been designed to enhance the bioavailability, stability, and retention of these drugs within the targeted lung area. Furthermore, these nanoparticle-based delivery systems offer several advantages, such as increased therapeutic efficacy and reduced side effects and toxicity. This review focuses on the recent advancements in drug delivery systems for some of the most important TKIs, shedding light on their potential in improving lung cancer treatment.

Surface and mechanical properties of polyurethane central venous catheters after repeated contact with chemotherapy excipient solutions

This article investigates the impact of the interactions between polyurethane central venous catheters and solutions containing excipients used in cisplatin and paclitaxel formulations. Changes to the properties of catheters and the leaching of catheter additives into the infused solutions were studied while these solutions were infused cyclically for several months. Chemotherapy treatment was mimicked in vitro in compliance with hospital practices. The treatment cycle was repeated 10 times, using solutions containing only the excipients. After 10 treatment cycles, no physical or chemical degradation of the catheter was observed. Mechanical performances were stable, but surface modifications occurred, causing the surface to become more hydrophobic. A loss in polyurethane antioxidant amount was observed in part due to a leaching phenomenon.

Acquisition of taxane resistance by p53 inactivation in ovarian cancer cells

Ovarian cancer is one of the most common gynecologic malignancies in women and has a poor prognosis. Taxanes are a class of standard first-line chemotherapeutic agents for the treatment of ovarian cancer. However, tumor-intrinsic and acquired resistance to taxanes poses major challenges to improving clinical outcomes. Hence, there is an urgent clinical need to understand the mechanisms of resistance in order to discover potential biomarkers and therapeutic strategies to increase taxane sensitivity in ovarian cancer. Here, we report the identification of an association between the TP53 status and taxane sensitivity in ovarian cancer cells through complementary experimental and informatics approaches. We found that TP53 inactivation is associated with taxane resistance in ovarian cancer cells, supported by the evidence from (i) drug sensitivity profiling with bioinformatic analysis of large-scale cancer therapeutic response and genomic datasets and (ii) gene signature identification based on experimental isogenic cell line models. Further, our studies revealed TP53-dependent gene expression patterns, such as overexpression of ACSM3, as potential predictive biomarkers of taxane resistance in ovarian cancer. The TP53-dependent hyperactivation of the WNT/β-catenin pathway discovered herein revealed a potential vulnerability to exploit in developing combination therapeutic strategies. Identification of this genotype-phenotype relationship between the TP53 status and taxane sensitivity sheds light on TP53-directed patient stratification and therapeutic discoveries for ovarian cancer treatment.

A Review of the Current Impact of Inhibitors of Apoptosis Proteins and Their Repression in Cancer

Simple Summary

The Inhibitor of Apoptosis (IAP) family of proteins has emerged as a potential pharmacological target in cancer. Abnormal expression of IAPs can lead to dysregulated cell suicide, promoting the development of different pathologies. In several cancer types, members of this protein family are overexpressed while their natural antagonist (Smac) appears to be downregulated, contributing to the acquisition of resistance to traditional therapy. The development of compounds that mimic the action of Smac showed promise in the re-sensitization of the cell suicide defense mechanism in cancer cells, particularly in combination with other treatments. Interaction with other molecules, such as tumor necrosis factor-α, in the tumor microenvironment reveals a complex interplay between IAPs and cancer.

Abstract

The Inhibitor of Apoptosis (IAP) family possesses the ability to inhibit programmed cell death through different mechanisms; additionally, some of its members have emerged as important regulators of the immune response. Both direct and indirect activity on caspases or the modulation of survival pathways, such as nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), have been implicated in mediating its effects. As a result, abnormal expression of inhibitor apoptosis proteins (IAPs) can lead to dysregulated apoptosis promoting the development of different pathologies. In several cancer types IAPs are overexpressed, while their natural antagonist, the second mitochondrial-derived activator of caspases (Smac), appears to be downregulated, potentially contributing to the acquisition of resistance to traditional therapy. Recently developed Smac mimetics counteract IAP activity and show promise in the re-sensitization to apoptosis in cancer cells. Given the modest impact of Smac mimetics when used as a monotherapy, pairing of these compounds with other treatment modalities is increasingly being explored. Modulation of molecules such as tumor necrosis factor-α (TNF-α) present in the tumor microenvironment have been suggested to contribute to putative therapeutic efficacy of IAP inhibition, although published results do not show this consistently underlining the complex interaction between IAPs and cancer.

State of the Art and Future Implications of SH003: Acting as a Therapeutic Anticancer Agent

Cancer ranks as the first leading cause of death globally. Despite the various types of cancer treatments, negative aspects of the treatments, such as side effects and drug resistance, have been a continuous dilemma for patients. Thus, natural compounds and herbal medicines have earned profound interest as chemopreventive agents for reducing burden for patients. SH003, a novel herbal medicine containing Astragalus membranaceus, Angelica gigas, and Trichosanthes kirilowii, showed the potential to act as an anticancer agent in previous research studies. A narrative review was conducted to present the significant highlights of the total 15 SH003 studies from the past nine years. SH003 has shown positive results in both in vivo and vitro studies against various types of cancer cells; furthermore, the first clinical trial was performed to identify the maximum tolerated dose among solid cancer patients. So far, the potential of SH003 as a chemotherapeutic agent has been well-documented in research studies; continuous work on SH003's efficacy and safety is required to facilitate better cancer patient care but is part of the knowledge needed to understand whether SH003 has the potential to become a pharmaceutical.

PSMA-targeted small-molecule docetaxel conjugate: Synthesis and preclinical evaluation

Prostate cancer is one of the most commonly diagnosed men's cancers and remains one of the leading causes of cancer death. The development of approaches to the treatment of this oncological disease is an ongoing process. In this work, we have carried out the selection of ligands for the creation of conjugates based on the drug docetaxel and synthesized a series of three docetaxel conjugates. In vitro cytotoxicity of these molecules was evaluated using the MTT assay. Based on the assay results, we selected the conjugate which showed cytotoxic potential close to unmodified docetaxel. At the same time, the molar solubility of the resulting compound increased up to 20 times in comparison with the drug itself. In vivo evaluation on 22Rv1 (PSMA+) xenograft model demonstrated a good potency of the synthesized conjugate to inhibit tumor growth: the inhibition turned out to be more than 80% at a dose of 30 mg/kg. Pharmacokinetic parameters of conjugate distribution were analyzed. Also, it was found that PSMA-targeted docetaxel conjugate is less toxic than docetaxel itself, the decrease of molar acute toxicity in comparison with free docetaxel was up to 20%. Obtained conjugate PSMA-DOC is a good candidate for further expanded preclinical trials because of high antitumor activity, fewer side toxic effects and better solubility.

Paclitaxel Impedes EGFR-mutated PC9 Cell Growth via Reactive Oxygen Species-mediated DNA Damage and EGFR/PI3K/AKT/mTOR Signaling Pathway Suppression

BACKGROUND/AIM

Paclitaxel is used as a first-line and subsequent therapy for the treatment of various cancers. However, the function and mechanisms of action of paclitaxel in non-small-cell lung cancer (NSCLC) remain unknown. In this study, the molecular mechanism underlying the anticancer activity of paclitaxel was investigated in vitro in a human NSCLC cell line carrying the EGFR exon 19 deletion (PC9).

MATERIALS AND METHODS

PC9 cells were treated with paclitaxel and then evaluated with a cell viability assay, DAPI staining, Giemsa staining, apoptosis assay, reactive oxygen species (ROS) assay, terminal deoxynucleotidyl transferase dUTP nick-end labeling assay and Western blotting.

RESULTS

Paclitaxel markedly decreased the viability of PC9 cells and induced morphological signs of apoptosis. The apoptotic effects of paclitaxel were observed through caspase cascade activation, along with ROS generation and loss of mitochondrial membrane potential (MMP). Furthermore, paclitaxel induced ROS-mediated DNA damage that triggered the activation of the extrinsic pathway of apoptosis via the up-regulation of death receptor (DR5) and caspase-8 activation. In addition, we found that paclitaxel effectively suppressed the EGFR/PI3K/AKT/mTOR signaling pathway to impede PC9 cell growth. Paclitaxel induced cell cycle arrest at the G1 phase in response to DNA damage, in association with the suppression of CDC25A, Cdk2 and Cyclin E1 protein expression.

CONCLUSION

Paclitaxel showed anticancer effects against NSCLC by activating extrinsic and intrinsic apoptotic pathways through enhancing ROS generation, inducing cell cycle arrest, and suppressing EGFR/PI3K/AKT/mTOR signaling pathway.

Synergistic Antitumor Activity of SH003 and Docetaxel via EGFR Signaling Inhibition in Non-Small Cell Lung Cancer

Epidermal growth factor receptor (EGFR) is overexpressed in lung cancer patients. Despite treatment with various EGFR tyrosine kinase inhibitors, recurrence and metastasis of lung cancer are inevitable. Docetaxel (DTX) is an effective conventional drug that is used to treat various cancers. Several researchers have studied the use of traditional herbal medicine in combination with docetaxel, to improve lung cancer treatment. SH003, a novel herbal mixture, exerts anticancer effects in different cancer cell types. Here, we aimed to investigate the apoptotic and anticancer effects of SH003 in combination with DTX, in human non-small-cell lung cancer (NSCLC). SH003, with DTX, induced apoptotic cell death, with increased expression of cleaved caspases and cleaved poly (ADP-ribose) polymerase in NSCLC cells. Moreover, SH003 and DTX induced the apoptosis of H460 cells via the suppression of the EGFR and signal transducer and activator of transcription 3 (STAT3) signaling pathways. In H460 tumor xenograft models, the administration of SH003 or docetaxel alone diminished tumor growth, and their combination effectively killed cancer cells, with increased expression of apoptotic markers and decreased expression of p-EGFR and p-STAT3. Collectively, the combination of SH003 and DTX may be a novel anticancer strategy to overcome the challenges that are associated with conventional lung cancer therapy.

Study of the Effect Epidermal Growth Factor Nanoparticles in the Treatment of Diabetic Rat Ulcer Skin and Regeneration

This study's objective is to analyze the effect of epidermal growth factor (EGF) nanoparticles on the healing of diabetic skin wounds and also, simultaneously, to investigate the mechanism of EGF nanoparticles to promote healing. In this manuscript, EGF nanoparticles were prepared, and also the drug loading rate of EGF nanoparticles was measured. In the meantime, a diabetic skin wound model was prepared with the use of rats. Then, the rats were split into four groups: EGF nanogroup, EGF group, empty particle group, and control group. Additionally, the results indicate that this study was successful in preparing EGF nanoparticles with a stable performance, and the drug was released for 24 hours. The wound healing in the EGF nanoparticle group was quicker than that in the EGF group. Furthermore, the area of EGF receptor-positive cells in the wound surface of the EGF nanogroup was higher than that of the EGF group, with the results demonstrating that EGF nanoparticles upregulated the expression of EGF receptors in wound surface cells, promoted wound surface healing, and had better efficacy than EGF.

Future Therapeutic Directions for Smac-Mimetics

It is well accepted that the ability of cancer cells to circumvent the cell death program that untransformed cells are subject to helps promote tumor growth. Strategies designed to reinstate the cell death program in cancer cells have therefore been investigated for decades. Overexpression of members of the Inhibitor of APoptosis (IAP) protein family is one possible mechanism hindering the death of cancer cells. To promote cell death, drugs that mimic natural IAP antagonists, such as second mitochondria-derived activator of caspases (Smac/DIABLO) were developed. Smac-Mimetics (SMs) have entered clinical trials for hematological and solid cancers, unfortunately with variable and limited results so far. This review explores the use of SMs for the treatment of cancer, their potential to synergize with up-coming treatments and, finally, discusses the challenges and optimism facing this strategy.

Paclitaxel interaction with cucurbit [7]uril and acyclic Cucurbit[4]uril nanocontainers: A computational approach

Paclitaxel (PTX) is a natural terpenoid compound that has been broadly studied for its antitumor activities and widely used as a chemotherapy medication. The treatment efficacy of PTX is affected by its low aqueous solubility, thus causing a subject of extensive research. In recent years, synthetic molecular containers such as cucurbit[n]urils (CB[n]s) and their derivatives have been significantly developing because of their remarkable ability to bind hydrophobic and cationic drugs. Recent experimental studies have shown that acyclic CB[n]-type containers (aCB[n]s), as new derivatives of the family of CB[n]s, increase the solubility of insoluble pharmaceuticals. However, the nature by which the drug interacts with carriers remains largely unknown. In this study, molecular docking and molecular dynamics (MD) simulation were performed to understand how CB[7] and aCB[4] nanocontainers interact with PTX which affect its aqueous solubility. The results clarify how the flexibility of containers is influenced by their structure and how this affects their interactions with PTX. Our results reveal that although both CB[7] and aCB[4] are capable of binding to PTX, the affinity to aCB[4] is higher than that of CB[7]. It has also been shown that the binding to both CB[7] and aCB[4] is probably an entropy-driven process. This research supports the potential use of the cucurbit[n]urils and their acyclic derivatives as drug delivery systems.

Synthesis, Biological Evaluation and Low-Toxic Formulation Development of Glycosylated Paclitaxel Prodrugs

Paclitaxel (PTX) is a famous anti-cancer drug with poor aqueous solubility. In clinical practices, Cremophor EL (polyethoxylated castor oil), a toxic surfactant, is used for dissolution of PTX, which accounts for serious side effects. In the present study, a single glucose-conjugated PTX prodrug (SG-PTX) and a double glucose-conjugated PTX prodrug (DG-PTX) were synthesized with a glycosylated strategy via succinate linkers. Both of the two prodrugs presented significant solubility improvement and drug-like lipophilicities. Compared to DG-PTX, SG-PTX manifested more promising release of the parent drug in serum. A high percentage of PTX released from SG-PTX could be detected after enzymatic hydrolysis of β-glucuronidase. Besides, both of the two prodrugs exhibited effective cytotoxicity against breast cancer cells and ovarian cancer cells, but presented reduced cytotoxicity against normal breast cells. Moreover, SG-PTX manifested impressive solubility in a low toxic formulation (without ethanol) with a different percentage of Cremophor EL. These results indicated that glycosylation is a promising strategy for PTX modification and SG-PTX may be a feasible and potential type of PTX prodrug. In addition, ethanol-free formulation with a low percentage of Cremophor EL might have the potential to develop a safer formulation for further studies of glycosylated PTX prodrugs.

Synergistic combination therapy of lung cancer using paclitaxel- and triptolide-coloaded lipid-polymer hybrid nanoparticles

Purpose

Non-small cell lung cancer (NSCLC) accounts for the majority of lung cancer. Lipid–polymer hybrid nanoparticles (LPNs) combine the advantages of both polymeric nanoparticles and liposomes into a single delivery platform. In this study, we engineered LPNs as the co-delivery system of paclitaxel (PTX) and triptolide (TL) to achieve synergistic therapeutic effect and reduced drug resistance.

Materials and methods

In this study, PTX- and TL-coloaded LPNs (P/T-LPNs) were fabricated by nanoprecipitation method using lipid and polymeric materials. The P/T-LPNs combination effects on human lung cancer cells were studied. Therapeutic potentials of P/T-LPNs were further determined using lung cancer cells-bearing mice model.

Results

The average particle sizes of LPNs were around 160 nm, with narrow size distribution below 0.2. The zeta potential value of LPNs was about −30 mV. The encapsulating efficiency (EE) of PTX and TL loaded in LPNs was over 85%. The cytotoxicity of dual drug loaded LPNs was higher than single drug loaded LPNs. The combination therapy showed synergistic when PTX:TL weight ratio was 5:3, indicating the synergy effects of the LPNs. In vivo tumor growth curve of the experimental group was more gentle opposed to the control group, and tumor volumes of P/T-LPNs and control group were 392 and 1,737 mm³, respectively. The inhibition rate on day 20 was 77.4% in the P/T-LPNs group, which is higher than the free drugs solution.

Conclusion

The in vivo and in vitro results proved the synergetic effect of the two drugs coloaded in LPNs on the lung cancer xenografts, with the least systemic toxic side effect.

Substituents at the C3' and C3'N positions are critical for taxanes to overcome acquired resistance of cancer cells to paclitaxel

We tested the role of substituents at the C3' and C3'N positions of the taxane molecule to identify taxane derivatives capable of overcoming acquired resistance to paclitaxel. Paclitaxel-resistant sublines SK-BR-3/PacR and MCF-7/PacR as well as the original paclitaxel-sensitive breast cancer cell lines SK-BR-3 and MCF-7 were used for testing. Increased expression of the ABCB1 transporter was found to be involved in the acquired resistance. We tested three groups of taxane derivatives: (1) phenyl group at both C3' and C3'N positions, (2) one phenyl at one of the C3' and C3'N positions and a non-aromatic group at the second position, (3) a non-aromatic group at both C3' and C3'N positions. We found that the presence of phenyl groups at both C3' and C3'N positions is associated with low capability of overcoming acquired paclitaxel resistance compared to taxanes containing at least one non-aromatic substituent at the C3' and C3'N positions. The increase in the ATPase activity of ABCB1 transporter after the application of taxanes from the first group was found to be somewhat higher than after the application of taxanes from the third group. Molecular docking studies demonstrated that the docking score was the lowest, i.e. the highest binding affinity, for taxanes from the first group. It was intermediate for taxanes from the second group, and the highest for taxanes from the third group. We conclude that at least one non-aromatic group at the C3' and C3'N positions of the taxane structure, resulting in reduced affinity to the ABCB1 transporter, brings about high capability of taxane to overcome acquired resistance of breast cancer cells to paclitaxel, due to less efficient transport of the taxane compound out of the cancer cells.

Cholic acid-based novel micellar nanoplatform for delivering FDA-approved taxanes

AIM

To structurally modify our existing cholic acid (CA)-based telodendrimer (TD; PEG^5K-CA₈) for effective micellar nanoencapsulation and delivery of the US FDA-approved members of taxane family.

MATERIALS & METHODS

Generation of hybrid TDs was achieved by replacing four of the eight CAs with biocompatible organic moieties using solution-phase peptide synthesis. Drug loading was done using the standard evaporation method.

RESULTS

Hybrid TDs can generate micelles with narrow size distributions, low critical micelle concentration values (1-6 μM), better hematocompatibility and lack of in vitro cytotoxicity.

CONCLUSION

Along with PEG^5K-CA₈, CA-based hybrid nanoplatform is the first of its kind that can stably encapsulate all three FDA-approved taxanes with nearly 100% efficiency up to 20% (w/w) loading.

Nanoparticle abraxane possesses impaired proliferation in A549 cells due to the underexpression of glucosamine 6-phosphate N-acetyltransferase 1 (GNPNAT1/GNA1)

Abraxane (Abr), a US Food and Drug Administration-approved albumin-bound nanoparticle applied for the treatment of non-small-cell lung cancer, has been reported to be more effective than paclitaxel (PTX). To further understand the molecular mechanisms that produce this superior drug efficacy of Abr, a quantitative proteomic approach has been applied to investigate the global protein expression profiles of lung cancer cell A549 treated with Abr and PTX. Only one protein, namely, glucosamine 6-phosphate N-acetyltransferase 1 (GNA1), showed significant differential expression (P<0.05) in the cutoff of 2.0 fold, suggesting that Abr can be used safely as a substitute for PTX. GNA1 is a key enzyme in the biosynthesis of uridine diphosphate-N-acetylglucosamine, which is an important donor substrate for N-linked glycosylation and has several important functions such as embryonic development and growth. Albumin plays a major role in the regulation of this protein. In summary, this study first shows that the superior drug effect of Abr is mainly due to the downregulation of GNA1, which causes proliferative delay and cell adhesion defect. It is also noteworthy that the deficiency of GNA1 might reduce insulin secretion which correlates with type 2 diabetes.

Aurora B expression modulates paclitaxel response in non-small cell lung cancer

Background:

Taxanes are mitotic poisons widely used in the treatment of non-small cell lung cancer (NSCLC), however, little is known about potential molecular modulators of response to these compounds. Aurora B (AURKB) is a critical regulator of the mitotic spindle assembly, previously shown overexpressed in NSCLC. Here we investigated the hypothesis that AURKB expression modulates the efficacy of taxanes in NSCLC cells.

Methods:

AURKB mRNA expression was determined by qPCR in 132 frozen NSCLC tissues and nine NSCLC cell lines. Aurora B expression was knocked down in cell lines using multiple shRNA constructs. Barasertib was used to specifically inhibit AURKB activity, determined by the level of H3S10 phosphorylation.

Results:

Frequent AURKB mRNA upregulation was observed in NSCLC tissues (P<0.0001), being more prominent in squamous carcinomas (P<0.0001). Aurora B expression in cell lines strongly correlated with sensitivity to both docetaxel (P=0.004) and paclitaxel (P=0.007). Aurora B knockdown derivatives consistently showed a dose-dependent association between low-AURKB expression and resistance to paclitaxel. Specific chemical inhibition of Aurora B activity also demonstrated a strong dose-dependent efficiency in triggering paclitaxel resistance.

Conclusions:

Aurora B activity is an important modulator of taxane response in NSCLC cells. This may lead to further insights into taxane sensitivity of NSCLC tumours.

LCL161 increases paclitaxel-induced apoptosis by degrading cIAP1 and cIAP2 in NSCLC

BACKGROUND

LCL161, a novel Smac mimetic, is known to have anti-tumor activity and improve chemosensitivity in various cancers. However, the function and mechanisms of the combination of LCL161 and paclitaxel in non-small cell lung cancer (NSCLC) remain unknown.

METHODS

Cellular inhibitor of apoptotic protein 1 and 2 (cIAP1&2) expression in NSCLC tissues and adjacent non-tumor tissues were assessed by immunohistochemistry. The correlations between cIAP1&2 expression and clinicopathological characteristics, prognosis were analyzed. Cell viability and apoptosis were measured by MTT assays and Flow cytometry. Western blot and co-immunoprecipitation assay were performed to measure the protein expression and interaction in NF-kB pathway. siRNA-mediated gene silencing and caspases activity assays were applied to demonstrate the role and mechanisms of cIAP1&2 and RIP1 in lung cancer cell apoptosis. Mouse xenograft NSCLC models were used in vivo to determine the therapeutic efficacy of LCL161 alone or in combination with paclitaxel.

RESULTS

The expression of cIAP1 and cIAP2 in Non-small cell lung cancer (NSCLC) tumors was significantly higher than that in adjacent normal tissues. cIAP1 was highly expressed in patients with late TNM stage NSCLC and a poor prognosis. Positivity for both cIAP1 and cIAP2 was an independent prognostic factor that indicated a poorer prognosis in NSCLC patients. LCL161, an IAP inhibitor, cooperated with paclitaxel to reduce cell viability and induce apoptosis in NSCLC cells. Molecular studies revealed that paclitaxel increased TNFα expression, thereby leading to the recruitment of various factors and the formation of the TRADD-TRAF2-RIP1-cIAP complex. LCL161 degraded cIAP1&2 and released RIP1 from the complex. Subsequently, RIP1 was stabilized and bound to caspase-8 and FADD, thereby forming the caspase-8/RIP1/FADD complex, which activated caspase-8, caspase-3 and ultimately lead to apoptosis. In nude mouse xenograft experiments, the combination of LCL161 and paclitaxel degraded cIAP1,2, activated caspase-3 and inhibited tumor growth with few toxic effects.

CONCLUSION

Thus, LCL161 could be a useful agent for the treatment of NSCLC in combination with paclitaxel.

An investigation of nitrile transforming enzymes in the chemo-enzymatic synthesis of the taxol sidechain

Paclitaxel (taxol) is an antimicrotubule agent widely used in the treatment of cancer. Taxol is prepared in a semisynthetic route by coupling the N-benzoyl-(2R,3S)-3-phenylisoserine sidechain to the baccatin III core structure. Precursors of the taxol sidechain have previously been prepared in chemoenzymatic approaches using acylases, lipases, and reductases, mostly featuring the enantioselective, enzymatic step early in the reaction pathway. Here, nitrile hydrolysing enzymes, namely nitrile hydratases and nitrilases, are investigated for the enzymatic hydrolysis of two different sidechain precursors. Both sidechain precursors, an openchain α-hydroxy-β-amino nitrile and a cyanodihydrooxazole, are suitable for coupling to baccatin III directly after the enzymatic step. An extensive set of nitrilases and nitrile hydratases was screened towards their activity and selectivity in the hydrolysis of two taxol sidechain precursors and their epimers. A number of nitrilases and nitrile hydratases converted both sidechain precursors and their epimers.

Zinc supplementation induces apoptosis and enhances antitumor efficacy of docetaxel in non-small-cell lung cancer

BACKGROUND

Exposure to exogenous zinc results in increased apoptosis, growth inhibition, and altered oxidative stress in cancer cells. Previous studies also suggested that zinc sensitizes some cancer cells to cytotoxic agents depending on the p53 status. Therefore, zinc supplementation may show anticancer efficacy solely and may increase docetaxel-induced cytotoxicity in non-small-cell lung cancer cells.

METHODS

Here, we report the effects of several concentrations of zinc combined with docetaxel on p53-wild-type (A549) and p53-null (H1299) cells. We evaluated cellular viability, apoptosis, and cell cycle progression as well as oxidative stress parameters, including superoxide dismutase, glutathione peroxidase, and malondialdehyde levels.

RESULTS

Zinc reduced the viability of A549 cells and increased the apoptotic response in both cell lines in a dose-dependent manner. Zinc also amplified the docetaxel effects and reduced its inhibitory concentration 50 (IC50) values. The superoxide dismutase levels increased in all treatment groups; however, glutathione peroxidase was slightly increased in the combination treatments. Zinc also caused malondialdehyde elevations at 50 μM and 100 μM.

CONCLUSION

Zinc has anticancer efficacy against non-small-cell lung cancer cells in the presence of functionally active p53 and enhances docetaxel efficacy in both p53-wild-type and p53-deficient cancer cells.

Pharmaceuticals that contain polycyclic hydrocarbon scaffolds

This review comprehensively explores approved pharmaceutical compounds that contain polycyclic scaffolds and the properties that these skeletons convey.

Comparison of demographics, treatment patterns, health care utilization, and costs among elderly patients with extensive-stage small cell and metastatic non-small cell lung cancers

Background

Limited data exist regarding real-world treatment patterns, resource utilization, and costs of extensive-stage small cell lung cancer (esSCLC) among elderly patients in the United States. While abundant data are available on treatment patterns in metastatic non-small cell lung cancer (mNSCLC), to our knowledge no data exist comparing costs and resource use between patients with esSCLC or mNSCLC.

Methods

We retrospectively analyzed administrative claims data (2000–2008) of patients aged ≥65 years from the linked Surveillance, Epidemiology and End Results (SEER)-Medicare database. Patients were selected on the basis of having newly diagnosed esSCLC (n=5,855) or mNSCLC (n=24,090) during 1/1/2000-12/31/2005, and were required to have received cancer-directed therapy. Survival and other measures were compared between esSCLC and mNSCLC patients using Kaplan-Meier log-rank and univariate chi-square and t-tests. Study measures were followed from first diagnosis date of either esSCLC or mNSCLC until the earlier of death or end of the database.

Results

Survival between the cohorts did not differ significantly: mean of 10.4 months for esSCLC patients versus 11.1 months for mNSCLC; median survival was 7.4 months versus 5.9 months. A higher percentage of mNSCLC patients (vs. esSCLC) received radiation therapy (75.6% vs. 65.4%; P < 0.001) and surgery (13.6% vs. 7.8%; P < 0.001) during the metastatic disease period. Conversely, a higher percentage of esSCLC patients than mNSCLC patients received chemotherapy (85.5% vs. 60.3%; P < 0.001), red blood-cell transfusion (20.7% vs. 10.9%; P < 0.001), platelet transfusion (5.6% vs. 1.8%; P < 0.001), and growth-factor support (59.0% vs. 39.5%; P < 0.001). esSCLC patients incurred higher lifetime disease-related costs ($44,167 vs. $37,932; P < 0.001) and all-cause costs ($70,549 vs. $67,176; P < 0.001) than mNSCLC patients.

Conclusions

Lifetime total and disease-related costs per patient were high. Increased use of chemotherapy, supportive care therapies (including growth factors), and disease-related hospitalizations were observed in esSCLC patients as compared with mNSCLC patients. Disease-related and all-cause costs for esSCLC also exceeded those of mNSCLC, except for hospice and skilled nursing services. Survival and per-patient costs for both groups underscore the unmet medical need for more effective therapies in patients with esSCLC or mNSCLC.

Electronic supplementary material

The online version of this article (doi:10.1186/s12913-014-0555-8) contains supplementary material, which is available to authorized users.

Update on taxanes in the first-line treatment of advanced non-small-cell lung cancer

Based on demonstrated favourable risk-benefit profiles, taxanes remain a key component in the first-line standard of care for advanced non-small-cell lung cancer (nsclc) and nsclc subtypes. In 2012, a novel taxane, nab-paclitaxel (Abraxane: Celgene Corporation, Summit, NJ, U.S.A.), was approved, in combination with carboplatin, for the first-line treatment of locally advanced or meta-static nsclc. The approval was granted because of demonstrated improved antitumour activity and tolerability compared with solvent-based paclitaxel-carboplatin in a phase iii trial. This review focuses on the evolution of first-line taxane therapy for advanced nsclc and the new options and advances in taxane therapy that might address unmet needs in advanced nsclc.

Constitutive androstane receptor ligands modulate the anti-tumor efficacy of paclitaxel in non-small cell lung cancer cells

Background

Lung tumors are the leading cause of cancer deaths worldwide and paclitaxel has proven to be useful for patients with lung cancer, however, acquired resistance is a major problem. To overcome this problem, one promising option is the use of Constitutive Androstane Receptor (CAR) ligands in combination with chemotherapeutics against cancer cells. Therefore, we wish to elucidate the effects of CAR ligands on the antineoplastic efficacy of paclitaxel in lung cancer cells.

Methodology/Principal Findings

Our results from cell viability assays exposing CAR agonist or inverse-agonist to mouse and human lung cancer cells modulated the antineoplastic effect of paclitaxel. The CAR agonists increased the effect of Paclitaxel in 6 of 7 lung cancer cell lines, whereas the inverse-agonist had no effect on paclitaxel cytotoxicity. Interestingly, the mCAR agonist TCPOBOP enhanced the expression of two tumor suppressor genes, namely WT1 and MGMT, which were additively enhanced in cells treated with CAR agonist in combination with paclitaxel. Also, in silico analysis showed that both paclitaxel and CAR agonist TCPOBOP docked into the mCAR structure but not the inverse agonist androstenol. Paclitaxel per se increases the expression of CAR in cancer cells. At last, we analyzed the expression of CAR in two public independent studies from The Cancer Genome Atlas (TCGA) of Non Small Cell Lung Cancer (NSCLC). CAR is expressed in variable levels in NSCLC samples and no association with overall survival was noted.

Conclusions/Significance

Taken together, our results demonstrated that CAR agonists modulate the antineoplastic efficacy of paclitaxel in mouse and human cancer cell lines. This effect was probably related by the enhanced expression of two tumor suppressor genes, viz. WT1 and MGMT. Most of NSCLC cases present CAR gene expression turning it possible to speculate the use of CAR modulation by ligands along with Paclitaxel in NSCLC therapy.

Oxidative stress induced in rat liver by anticancer drugs doxorubicin, paclitaxel and docetaxel

PURPOSE

Oxidative stress generated by anticancer drugs in non-targeted tissues, is considered as a significant factor responsible for their severe side effects, e.g. cardiotoxicity, neurotoxicity and hepatotoxicity. Lack of data on the effect of concurrent administration of commonly used anticancer drugs: doxorubicin (DOX), paclitaxel (PTX) and docetaxel (DTX) on normal tissue, prompted us to examine the markers of oxidative stress in the liver of rats treated with these drugs.

MATERIAL/METHODS

Male Wistar rats of average weight 200 g were injected intraperitoneally (i.p.) with 10 mg/kg of body weight (b.w.) of DOX, PTX and DTX. The drugs were given alone or in combinations DOX+taxane. The activities of superoxide dismutase (SOD), catalase (CAT), low molecular weight and total thiols and thiobarbituric acid-reactive substances (TBARS) were estimated.

RESULTS

Combination of two drugs generated greater changes than single agents. Concurrent administration of DOX and PTX increased SOD activity and TBARS, decreased the amount of low molecular weight and total thiols, but did not cause any changes in the activity of catalase. Combination of DOX and DTX induced similar changes except for the activity of catalase, which decreased after the treatment. Of the three drugs only DTX significantly decreased the activity of SOD. However, both taxanes increased the activity of catalase. Although a decrease in concentration of -SH groups, depletion of glutathione and an increase of TBARS were observed after treatment with single drugs, the changes were not statistically significant.

CONCLUSION

Concurrent administration of DOX and taxane induced enhanced oxidative stress in comparison to single drugs, which suggests their synergistic prooxidant mode of action in liver.

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

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

Cytoprotective role of autophagy during paclitaxel-induced apoptosis in Saos-2 osteosarcoma cells

Osteosarcoma (OS) is the most common primary malignant bone cancer in children and adolescents. Although paclitaxel (PCX) has been considered one of the most important cancer chemotherapeutic drugs, the current protocols for OS treatment do not incorporate this agent. Therefore, the purpose of this study was to evaluate the induction of cell death in OS cells after exposure to PCX, to identify the cell death mechanism(s) activated by PCX and to investigate whether autophagy is associated with PCX-induced apoptosis. The results of the present study confirmed that exposure to low PCX concentrations can induce apoptotic cell death in Saos-2 cells; furthermore, caspase-3 activation, PARP degradation and XIAP downregulation were observed in combination with PCX-induced apoptosis. The potential involvement of mitochondrial events (intrinsic apoptotic pathway) in PCX-induced apoptosis in OS cells was verified by the alteration (depolarization) of mitochondrial membrane potential. In addition, pretreatment with 3-methyladenine (3-MA), a specific inhibitor of autophagy, significantly increased PCX-induced apoptotic cell death in Saos-2 cells. The augmentation of PCX-induced apoptosis by 3-MA was accompanied by increase in the cytochrome c release from the mitochondria, caspase-3 activity and XIAP downregulation, which suggests that inhibiting autophagy further stimulates the PCX-induced mitochondrion-related (intrinsic) apoptotic pathway by provoking caspase-3 activation. Thus, autophagy observed during PCX-induced apoptosis in Saos-2 OS cells represents the role of cytoprotection in cellular homeostatic processes. In conclusion, the results of this study revealed that PCX exposure effectively induces OS cell death by apoptosis associated with the mitochondrial-mediated caspase-dependent pathway. PCX can increase autophagic activity and suppressing autophagy enhances PCX-induced apoptosis in OS cells. Therefore, it is suggested that combination treatment involving low-dose PCX therapy and autophagy inhibitor therapy could be an effective and potent strategy for improved chemotherapy for OS in the near future.

Paclitaxel-loaded polymeric micelle (230 mg/m(2)) and cisplatin (60 mg/m(2)) vs. paclitaxel (175 mg/m(2)) and cisplatin (60 mg/m(2)) in advanced non-small-cell lung cancer: a multicenter randomized phase IIB trial

INTRODUCTION

The development of paclitaxel-loaded polymeric micelle (PPM) has circumvented many of the infusion-related difficulties associated with standard solvent-based paclitaxel. PPM plus cisplatin combination chemotherapy showed significant antitumor activity in phase I and II studies. This prospective randomized controlled phase IIB study assessed the noninferiority of the efficacy and tolerability of high-dose PPM plus cisplatin to a standard dose of paclitaxel plus cisplatin.

PATIENTS AND METHODS

Patients with stage IIIB/IV or recurrent non-small-cell lung cancer (NSCLC) who were chemonaive were eligible for participation. The patients were randomly assigned to receive PPM 230 mg/m(2) plus cisplatin 60 mg/m(2) or paclitaxel 175 mg/m(2) plus cisplatin 60 mg/m(2) once every 3-week cycle. The primary endpoint was to compare the response rate (RR) between the groups with coprimary analyses to assess noninferiority. Secondary endpoints included progression-free survival, overall survival, and safety.

RESULTS

A total of 276 patients were randomized to PPM plus cisplatin (n = 140) or paclitaxel plus cisplatin (n = 136). RR was 43.6% in the PPM plus cisplatin group and 41.9% in the paclitaxel plus cisplatin group. Noninferiority of PPM plus cisplatin compared with paclitaxel plus cisplatin was confirmed for RR. There were no differences in progression-free survival and overall survival between the groups. Although there was a higher rate of grade 3 neutropenia in the PPM plus cisplatin group, the overall rate of adverse events was comparable between the 2 groups.

CONCLUSION

PPM in combination with cisplatin was well tolerated, and its response rate was noninferior to that of paclitaxel plus cisplatin in patients with advanced NSCLC and who were chemonaive.

miR-135a contributes to paclitaxel resistance in tumor cells both in vitro and in vivo

Cancer cell resistance to paclitaxel continues to be a major clinical problem. In this study, we utilized microRNA (miRNA) arrays to screen for differentially expressed miRNAs in paclitaxel-resistant cell lines established in vitro. We observed concordant upregulation of miR-135a in paclitaxel-resistant cell lines representing three human malignancies. Subsequently, the role of miRNA-135a was evaluated in an in vivo model of paclitaxel resistance. In this model, mice were inoculated subcutaneously with a non-small cell lung carcinoma cell line and treated with paclitaxel for a prolonged period. In paclitaxel-resistant cell lines, established either in vitro or in vivo, blockage of miR-135a sensitized resistant cell lines to paclitaxel-induced cell death. We further demonstrated a correlation between paclitaxel response and miR-135a expression in paclitaxel-resistant subclones that were established in vivo. The paclitaxel-resistant phenotype of these subclones was maintained upon retransplantation in new mice, as shown by decreased tumor response upon paclitaxel treatment compared with controls. Upregulation of miR-135a was associated with reduced expression of the adenomatous polyposis coli gene (APC). APC knockdown increased paclitaxel resistance in parental cell lines. Our results indicate that paclitaxel resistance is associated with upregulation of miR-135a, both in vitro and in vivo, and is in part determined by miR-135a-mediated downregulation of APC.

Rapamycin potentiates cytotoxicity by docetaxel possibly through downregulation of Survivin in lung cancer cells

BACKGROUND

To elucidate whether rapamycin, the inhibitor of mTOR (mammalian target of rapamycin), can potentiate the cytotoxic effect of docetaxel in lung cancer cells and to probe the mechanism underlying such enhancement.

METHODS

Lung cancer cells were treated with docetaxel and rapamycin. The effect on the proliferation of lung cancer cells was evaluated using the MTT method, and cell apoptosis was measured by flow cytometry. Protein expression and level of phosphorylation were assayed using Western Blot method.

RESULTS

Co-treatment of rapamycin and docetaxel was found to favorably enhance the cytotoxic effect of docetaxel in four lung cancer cell lines. This tumoricidal boost is associated with a reduction in the expression and phosphorylation levels of Survivin and ERK1/2, respectively.

CONCLUSION

The combined application of mTOR inhibitor and docetaxel led to a greater degree of cancer cell killing than that by either compound used alone. Therefore, this combination warrants further investigation in its suitability of serving as a novel therapeutic scheme for treating advanced and recurrent lung cancer patients.

Early, progressive, and sustained dysfunction of sensory axons underlies paclitaxel-induced neuropathy

Paclitaxel is used in the adjuvant treatment of breast cancer. It induces disabling and potentially long-lasting sensory neuropathy. This study systematically and prospectively investigated sensory function, using clinical grading scales, quantitative sensory testing, and neurophysiological and nerve excitability studies in 28 patients with early-stage breast cancer. After administration of 529 ± 41 mg/m(2) paclitaxel, 71% of patients developed neuropathic symptoms by 6 weeks of treatment. Early and progressive increases in stimulus threshold (P < 0.05) and reduction in sensory amplitudes from 47.0 ± 3.3 μV to 42.4 ± 3.4 μV (P < 0.05) occurred by 4 weeks, with a further reduction by final treatment (33.7 ± 3.0 μV, P < 0.001). The majority of patients (63%) did not experience recovery of neuropathic symptoms at follow-up. Axonal disruption did not relate to membrane conductance dysfunction. We found that paclitaxel produces early sensory dysfunction and leads to persistent neuropathy. Importantly, significant axonal dysfunction within the first month of treatment predated symptom onset, suggesting a window for neuroprotective therapies.

Near-infrared light triggers release of Paclitaxel from biodegradable microspheres: photothermal effect and enhanced antitumor activity

Despite advances in controlled drug delivery, reliable methods for activatable, high-resolution control of drug release are needed. The hypothesis that the photothermal effect mediated by a near-infrared (NIR) laser and hollow gold nanospheres (HAuNSs) could modulate the release of anticancer agents is tested with biodegradable and biocompatible microspheres (1-15 microm) containing the antitumor drug paclitaxel (PTX) and HAuNSs (approximately 35 nm in diameter), which display surface plasmon absorbance in the NIR region. HAuNS-containing microspheres exhibit a NIR-induced thermal effect similar to that of plain HAuNSs. Rapid, repetitive PTX release from the PTX/HAuNS-containing microspheres is observed upon irradiation with NIR light (808 nm), whereas PTX release is insignificant when the NIR light is switched off. The release of PTX from the microspheres is readily controlled by the output power of the NIR laser, duration of irradiation, treatment frequency, and concentration of HAuNSs embedded inside the microspheres. In vitro, cancer cells incubated with PTX/HAuNS-loaded microspheres and irradiated with NIR light display significantly greater cytotoxic effects than cells incubated with the microspheres alone or cells irradiated with NIR light alone, owing to NIR-light-triggered drug release. Treatment of human U87 gliomas and MDA-MB-231 mammary tumor xenografts in nude mice with intratumoral injections of PTX/HAuNS-loaded microspheres followed by NIR irradiation results in significant tumor-growth delay compared to tumors treated with HAuNS-loaded microspheres (no PTX) and NIR irradiation or with PTX/HAuNS-loaded microspheres alone. The data support the feasibility of a therapeutic approach in which NIR light is used for simultaneous modulation of drug release and induction of photothermal cell killing.

HFT-T, a targeting nanoparticle, enhances specific delivery of paclitaxel to folate receptor-positive tumors

Nonspecific distribution of chemotherapeutic drugs (such as paclitaxel) is a major factor contributing to side effects and poor clinical outcomes in the treatment of human head and neck cancer. To develop novel drug delivery systems with enhanced efficacy and minimized adverse effects, we synthesized a ternary conjugate heparin-folic acid-paclitaxel (HFT), loaded with additional paclitaxel (T). The resulting nanoparticle, HFT-T, is expected to retain the antitumor activity of paclitaxel and specifically target folate receptor (FR)-expressing tumors, thereby increasing the bioavailability and efficacy of paclitaxel. In vitro experiments found that HFT-T selectively recognizes FR-positive human head and neck cancer cell line KB-3-1, displaying higher cytotoxicity compared to the free form of paclitaxel. In a subcutaneous KB-3-1 xenograft model, HFT-T administration enhanced the specific delivery of paclitaxel into tumor tissues and remarkably improved antitumor efficacy of paclitaxel. The average tumor volume in the HFT-T treatment group was 92.9 +/- 78.2 mm(3) vs 1670.3 +/- 286.1 mm(3) in the mice treated with free paclitaxel. Furthermore, paclitaxel tumors showed a resurgence of growth after several weeks of treatment, but this was not observed with HFT-T. This indicates that HFT-T could be more effective in preventing tumors from developing drug resistance. No significant acute in vivo toxicity was observed. These results indicate that specific delivery of paclitaxel with a ternary structured nanoparticle (HFT-T) targeting FR-positive tumor is a promising strategy to enhance chemotherapy efficacy and minimize adverse effects.

The role of Bcl-xL and nuclear factor-kappaB in the effect of taxol on the viability of dendritic cells

Taxol has been used effectively in cancer therapies. Our previous study demonstrated that taxol induced altered maturation and improved viability of dendritic cells (DCs). However, the effects of taxol on DC viability have not been fully elucidated. In the present study, flow cytometric analyses revealed that taxol treatment significantly increased the number of viable DCs and the expression levels of a representative anti-apoptotic protein Bcl-xL. Furthermore, mobilization of the p65 subunit of nuclear factor-κB (NF-κB) from the cytosol to the nucleus in DCs was observed by confocal microscopy. An inhibition assay using N-p-tosyl-_L-phenylalanine chloromethyl ketone confirmed that NF-κB was intimately involved in the effects of taxol on DC viability. In addition, we investigated the mechanisms of taxol enhancement of DC viability. Since taxol is a popular anticancer agent used in clinic, this study may provide a rationale for the use of taxol in DC immunotherapy to treat cancer patients. Taken together, these results confirm that taxol increases DC viability, and this information may provide new insights for new clinical applications of both taxol and DCs.

Adenoendocrine cell carcinoma of the gallbladder clinically mimicking squamous cell carcinoma

We present the case of a 62-year-old Japanese man whose histological diagnosis was adenoendocrine cell carcinoma of the gallbladder at autopsy, but whose antemortem diagnosis was squamous cell carcinoma. The patient was admitted to hospital with complaints of occasional vomiting and abdominal pain. Abdominal computed tomography revealed a large tumor on the gallbladder involving the adjacent liver, colon, and duodenum, with multiple metastases in the greater omentum and paraportal lymph nodes. The serum level of squamous cell carcinoma antigen (SCCA) was high, whereas that of carbohydrate antigen (CA) 19-9, as well as that of carcinoembryonic antigen (CEA) was within the normal range. Due to these clinical features, we first suspected advanced squamous cell carcinoma of the gallbladder. After two cycles of gemcitabine monotherapy, the tumor had become enlarged and the regimen was changed to a combination of docetaxel and cisplatin. Though tumor regression was achieved and his serum SCCA level normalized after 3 months, the patient rejected additional chemotherapy and died 8 months after the diagnosis. The histopathological findings made by autopsy demonstrated the tumor to be an adenoendocrine cell carcinoma without squamous carcinoma cells. The case is interesting in that the clinical features were similar to those of squamous cell carcinoma of the gallbladder.

The taccalonolides: microtubule stabilizers that circumvent clinically relevant taxane resistance mechanisms

The taccalonolides are a class of structurally and mechanistically distinct microtubule-stabilizing agents isolated from Tacca chantrieri. A crucial feature of the taxane family of microtubule stabilizers is their susceptibility to cellular resistance mechanisms including overexpression of P-glycoprotein (Pgp), multidrug resistance protein 7 (MRP7), and the betaIII isotype of tubulin. The ability of four taccalonolides, A, E, B, and N, to circumvent these multidrug resistance mechanisms was studied. Taccalonolides A, E, B, and N were effective in vitro against cell lines that overexpress Pgp and MRP7. In addition, taccalonolides A and E were highly active in vivo against a doxorubicin- and paclitaxel-resistant Pgp-expressing tumor, Mam17/ADR. An isogenic HeLa-derived cell line that expresses the betaIII isotype of tubulin was generated to evaluate the effect of betaIII-tubulin on drug sensitivity. When compared with parental HeLa cells, the betaIII-tubulin-overexpressing cell line was less sensitive to paclitaxel, docetaxel, epothilone B, and vinblastine. In striking contrast, the betaIII-tubulin-overexpressing cell line showed greater sensitivity to all four taccalonolides. These data cumulatively suggest that the taccalonolides have advantages over the taxanes in their ability to circumvent multiple drug resistance mechanisms. The ability of the taccalonolides to overcome clinically relevant mechanisms of drug resistance in vitro and in vivo confirms that the taccalonolides represent a valuable addition to the family of microtubule-stabilizing compounds with clinical potential.

Oral bioavailability of a novel paclitaxel formulation (Genetaxyl) administered with cyclosporin A in cancer patients

The formulation excipient Cremophor EL (CrEL) is known to limit the absorption of oral paclitaxel given together with cyclosporin A. We hypothesized that the use of oral Genetaxyl, a paclitaxel formulation containing only 20% CrEL would have an improved oral bioavailability. Cohorts of six patients were treated with oral Genetaxyl at a dose of 60, 120, or 180 mg/m2 and 10 mg/kg of oral cyclosporin A in cycle 1. In cycle 2, patients received intravenous (i.v.) Genetaxyl (175 mg/m2, 3-h infusion). Three additional patients received one dose of generic i.v. paclitaxel (Genaxol, containing 50% CrEL; 175mg/m2, 3-h infusion). The median area under the plasma concentration-time curve (AUC) and peak concentration of total paclitaxel following i.v. Genetaxyl were lower than those for i.v. Genaxol, as a result of significantly increased clearance (P = 0.017), and the AUC ratio for unbound to total paclitaxel for i.v. Genetaxyl was about two times higher than that for i.v. Genaxol (P = 0.0077). After oral administration of Genetaxyl at doses of 60, 120, and 180 mg/m2, the median total paclitaxel AUCs were 1.29, 1.60, and 1.85 microg x h/ml, respectively, suggesting a less than proportional increase in systemic exposure with increasing doses. The corresponding median values for the apparent bioavailability of oral Genetaxyl were similar when compared with i.v. Genetaxyl, when calculated either on the basis of data for total paclitaxel (30.1%) or unbound paclitaxel (30.6%).

Treatment for lung metastasis from head and neck squamous cell carcinoma: a preliminary study of docetaxel

OBJECTIVES

The aims of the study were to investigate the prognosis of patients with lung metastasis after treatment for head and neck squamous cell carcinoma (HANSCC) and to preliminarily evaluate the efficacy and toxicity of docetaxel (DOC)-based chemotherapy.

MATERIALS AND METHODS

The effectiveness of the chemotherapy was evaluated retrospectively according to the tumor response rate and survival time post-metastasis. Thirty patients were enrolled in the study. Twenty-seven have died, two are living, and one was lost during follow-up. Nineteen patients were treated for lung metastasis with chemotherapy. DOC-based chemotherapy was given to seven patients and non-DOC-based chemotherapy to 12.

RESULTS AND DISCUSSION

The response rate was 28.6% for the first administration of DOC-based chemotherapy, but only 8.3% for the non-DOC-based chemotherapy. Thus, DOC-based chemotherapy had a better response rate for lung metastases than other chemotherapy agents tested. Although the sample size was small, DOC seems to shrink or inhibit the growth of lung metastases in patients with primary HANSCC.