Phase II study of taxol, merbarone, and piroxantrone in stage IV non-small-cell lung cancer: The Eastern Cooperative Oncology Group Results

Cubosomes: An Emerging and Promising Drug Delivery System for Enhancing Cancer Therapy

Cancer and other diseases can be treated with cubosomes, which are lyotropic nonlamellar liquid crystalline nanoparticles (LCNs). These cubosomes can potentially be a highly versatile carrier with theranostic efficacy, as they can be ingested, applied topically, or injected intravenously. Recent years have seen substantial progress in the synthesis, characterization, regulation of drug release patterns, and target selectivity of loaded anticancer bioactive compounds. However, its use in clinical settings has been slow and necessitates additional proof. Recent progress and roadblocks in using cubosomes as a nanotechnological intervention against various cancers are highlighted. In the last few decades, advances in biomedical nanotechnology have allowed for the development of "smart" drug delivery devices that can adapt to external stimuli. By improving therapeutic targeting efficacy and lowering the negative effects of payloads, these well-defined nanoplatforms can potentially promote patient compliance in response to specific stimuli. Liposomes and niosomes, two other well-known vesicular systems, share a lipid basis with cubosomes. Possible applications include a novel medication delivery system for hydrophilic, lipophilic, and amphiphilic drugs. We evaluate the literature on cubosomes, emphasizing their potential use in tumor-targeted drug delivery applications and critiquing existing explanations for cubosome self-assembly, composition, and production. As cubosome dispersion has bioadhesive and compatible features, numerous drug delivery applications, including oral, ocular, and transdermal, are also discussed in this review.

Identification of cardiotoxicity related to non-small cell lung cancer (NSCLC) treatments: A systematic review

Introduction: In the last few decades, there has been a rapid development in cancer therapies and improved detection strategies, hence the death rates caused by cancer have decreased. However, it has been reported that cardiovascular disease has become the second leading cause of long-term morbidity and fatality among cancer survivors. Cardiotoxicity from anticancer drugs affects the heart's function and structure and can occur during any stage of the cancer treatments, which leads to the development of cardiovascular disease. Objectives: To investigate the association between anticancer drugs for non-small cell lung cancer (NSCLC) and cardiotoxicity as to whether: different classes of anticancer drugs demonstrate different cardiotoxicity potentials; different dosages of the same drug in initial treatment affect the degree of cardiotoxicity; and accumulated dosage and/or duration of treatments affect the degree of cardiotoxicity. Methods: This systematic review included studies involving patients over 18 years old with NSCLC and excluded studies in which patients' treatments involve radiotherapy only. Electronic databases and registers including Cochrane Library, National Cancer Institute (NCI) Database, PubMed, Scopus, Web of Science, ClinicalTrials.gov and the European Union Clinical Trials Register were systematically searched from the earliest available date up until November 2020. A full version protocol of this systematic review (CRD42020191760) had been published on PROSPERO. Results: A total of 1785 records were identified using specific search terms through the databases and registers; 74 eligible studies were included for data extraction. Based on data extracted from the included studies, anticancer drugs for NSCLC that are associated with cardiovascular events include bevacizumab, carboplatin, cisplatin, crizotinib, docetaxel, erlotinib, gemcitabine and paclitaxel. Hypertension was the most reported cardiotoxicity as 30 studies documented this cardiovascular adverse event. Other reported treatment-related cardiotoxicities include arrhythmias, atrial fibrillation, bradycardia, cardiac arrest, cardiac failure, coronary artery disease, heart failure, ischemia, left ventricular dysfunction, myocardial infarction, palpitations, and tachycardia. Conclusion: The findings of this systematic review have provided a better understanding of the possible association between cardiotoxicities and anticancer drugs for NSCLC. Whilst variation is observed across different drug classes, the lack of information available on cardiac monitoring can result in underestimation of this association. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020191760, identifier PROSPERO CRD42020191760.

Chemotherapeutic properties and side-effects associated with the clinical practice of terpene alkaloids: paclitaxel, docetaxel, and cabazitaxel

Over the years, many biological and synthetic agents have been explored and tested in attempts to halt the spread of cancer and/or cure it. Currently, several natural compounds have and are being considered in this regard. For example, paclitaxel is a potent anticancer drug that originates from the tree Taxus brevifolia. Paclitaxel has several derivatives, namely, docetaxel and cabazitaxel. These agents work by disrupting microtubule assembling dynamics and inducing cell cycle arrest at the G2/M phase of the cell cycle, ultimately triggering apoptosis. Such features have helped to establish paclitaxel as an authoritative therapeutic compound against neoplastic disorders. After the completion of compound (hemi) synthesis, this drug received approval for the treatment of solid tumors either alone or in combination with other agents. In this review, we explore the mechanisms of action of paclitaxel and its derivatives, the different formulations available, as well as the molecular pathways of cancer resistance, potential risks, and other therapeutic applications. In addition, the role of paclitaxel in hematological malignancies is explored, and potential limitations in the therapeutic use of paclitaxel at the clinical level are examined. Furthermore, paclitaxel is known to cause increased antigen presentation. The immunomodulatory potential of taxanes, alone or in combination with other pharmacologic agents, is explored. Despite terpene-alkaloids derivatives' anti-mitotic potential, the impact of this class of drugs on other oncogenic pathways, such as epithelial-to-mesenchymal transition and the epigenetic modulation of the transcription profile of cancer cells, is also analyzed, shedding light on potential future chemotherapeutic approaches to cancer.

PLGA-Lipid Hybrid Nanoparticles for Overcoming Paclitaxel Tolerance in Anoikis-Resistant Lung Cancer Cells

Drug resistance and metastasis are two major obstacles to cancer chemotherapy. During metastasis, cancer cells can survive as floating cells in the blood or lymphatic circulatory system, due to the acquisition of resistance to anoikis-a programmed cell death activated by loss of extracellular matrix attachment. The anoikis-resistant lung cancer cells also develop drug resistance. In this study, paclitaxel-encapsulated PLGA-lipid hybrid nanoparticles (PLHNPs) were formulated by nanoprecipitation combined with self-assembly. The paclitaxel-PLHNPs had an average particle size of 103.0 ± 1.6 nm and a zeta potential value of -52.9 mV with the monodisperse distribution. Cytotoxicity of the nanoparticles was evaluated in A549 human lung cancer cells cultivated as floating cells under non-adherent conditions, compared with A549 attached cells. The floating cells exhibited anoikis resistance as shown by a lack of caspase-3 activation, in contrast to floating normal epithelial cells. Paclitaxel tolerance was evident in floating cells which had an IC₅₀ value of 418.56 nM, compared to an IC₅₀ value of 7.88 nM for attached cells. Paclitaxel-PLHNPs significantly reduced the IC₅₀ values in both attached cells (IC₅₀ value of 0.11 nM, 71.6-fold decrease) and floating cells (IC₅₀ value of 1.13 nM, 370.4-fold decrease). This report demonstrated the potential of PLHNPs to improve the efficacy of the chemotherapeutic drug paclitaxel, for eradicating anoikis-resistant lung cancer cells during metastasis.

High-throughput screening of the ReFRAME, Pandemic Box, and COVID Box drug repurposing libraries against SARS-CoV-2 nsp15 endoribonuclease to identify small-molecule inhibitors of viral activity

SARS-CoV-2 has caused a global pandemic, and has taken over 1.7 million lives as of mid-December, 2020. Although great progress has been made in the development of effective countermeasures, with several pharmaceutical companies approved or poised to deliver vaccines to market, there is still an unmet need of essential antiviral drugs with therapeutic impact for the treatment of moderate-to-severe COVID-19. Towards this goal, a high-throughput assay was used to screen SARS-CoV-2 nsp15 uracil-dependent endonuclease (endoU) function against 13 thousand compounds from drug and lead repurposing compound libraries. While over 80% of initial hit compounds were pan-assay inhibitory compounds, three hits were confirmed as nsp15 endoU inhibitors in the 1-20 μM range in vitro. Furthermore, Exebryl-1, a ß-amyloid anti-aggregation molecule for Alzheimer's therapy, was shown to have antiviral activity between 10 to 66 μM, in Vero 76, Caco-2, and Calu-3 cells. Although the inhibitory concentrations determined for Exebryl-1 exceed those recommended for therapeutic intervention, our findings show great promise for further optimization of Exebryl-1 as an nsp15 endoU inhibitor and as a SARS-CoV-2 antiviral.

Overcoming the diverse mechanisms of multidrug resistance in lung cancer cells by photodynamic therapy using pTHPP-loaded PLGA-lipid hybrid nanoparticles

Multidrug resistance (MDR) and the spread of cancer cells (metastasis) are major causes leading to failure of cancer treatment. MDR can develop in two main ways, with differences in their mechanisms for drug resistance, first drug-selected MDR developing after chemotherapeutic treatment, and metastasis-associated MDR acquired by cellular adaptation to microenvironmental changes during metastasis. This study aims to use a nanoparticle-mediated photodynamic therapy (NPs/PDT) approach to overcome both types of MDR. A photosensitizer, 5,10,15,20-Tetrakis(4-hydroxy-phenyl)-21H,23H-porphine (pTHPP) was loaded into poly(D,L-lactide-co-glycolide) (PLGA)-lipid hybrid nanoparticles. The photocytotoxic effect of the nanoparticles was evaluated using two different MDR models established from one cell line, A549 human lung adenocarcinoma, including (1) A549RT-eto, a MDR cell line derived from A549 cells by drug-selection, and (2) detachment-induced MDR acquired by A549 cells when cultured as floating cells under non-adherent conditions, which mimic metastasizing cancer cells in the blood/lymphatic circulation. In the drug-selected MDR model, A549RT-eto cells displayed 17.4- and 1.8-fold resistance to Etoposide and Paclitaxel, respectively, compared to the A549 parental cells. In contrast to treatment with anticancer drugs, NPs/PDT with pTHPP-loaded nanoparticles resulted in equal photocytotoxic effect in A549RT-eto and parental cells. Intracellular pTHPP accumulation and light-induced superoxide anion generation were observed at similar levels in the two cell lines. The NPs/PDT killed A549RT-eto and parental cells through apoptosis as revealed by flow cytometry. In the metastasis-associated MDR model, A549 floating cells exhibited resistance to Etoposide (11.6-fold) and Paclitaxel (57.8-fold) compared to A549 attached cells, but the floating cells failed to show resistance against the photocytotoxic effect of the NPs/PDT. The MDR overcoming activity of NPs/PDT is mainly due to delivery ability of the PLGA-lipid hybrid nanoparticles. In conclusion, this work suggests that PLGA-lipid hybrid nanoparticles have potential in delivering photosensitizer or chemotherapeutic drug for treating both drug-selected and metastasis-associated MDR lung cancer cells.

Predicting Paclitaxel Disposition in Humans With Whole-Body Physiologically-Based Pharmacokinetic Modeling

Paclitaxel is a commonly used drug in the treatment of multiple solid tumors, including cancers of the breast, lung, and ovaries. Despite the established exposure–pharmacodynamic relationships for paclitaxel, treatment is associated with wide interindividual pharmacokinetic variability that leads to unpredictability of the agent's clinical activity and toxicity. We hypothesized that physiologically‐based modeling approaches could be employed to predict the human pharmacokinetics of paclitaxel following administration of the approved Cremophor‐based formulation (Taxol). The model was developed from tissue distribution studies performed in mice and applied to plasma concentration‐time data obtained in adult cancer patients receiving Taxol at the approved dose and schedule (175 mg/m² by a 3‐hour intravenous infusion), taking into account interspecies differences in physiological parameters. The final model adequately captured the observed concentrations in patients and allowed prediction of paclitaxel distribution profiles in multiple target organs and can be applied to further refine the chemotherapeutic treatment with a clinically important agent.

The Paternò–Büchi reaction – a comprehensive review

This review represents the most complete description of the scientific results obtained on a photochemical reaction described 110 years ago by an Italian scientist.

The clinical efficacy and safety of paclitaxel combined with avastin for NSCLC patients diagnosed with malignant pleural effusion

OBJECTIVE

The current study aimed to investigate the clinical efficacy of paclitaxel combined with avastin for non-small cell lung cancer (NSCLC) patients diagnosed with malignant pleural effusion (MPE).

METHOD

Total of 33 patients diagnosed with NSCLC as well as malignant pleural effusion were included. All of them received paclitaxel (175 mg/m2) and avastin (5 mg/kg). Clinical efficacy was evaluated using the total response rate, overall survival, progression-free survival and changes in MPE volume. Adverse events and rates of toxicities were examined as well.

RESULTS

The total response rate reached 77% while the overall survival and the median progression-free survival were respectively 22.2 months and 8.4 months. Toxicities of grade 3-4 consisted of neutropenia in 57% of patients, anemia in 17% of them, febrile neutropenia in 11%, as well as anorexia in 7%. No treatment-correlated deaths were found.

CONCLUSION

Paclitaxel combined with avastin decreased MPE volume and increased survival rate of NSCLC patients via inhibiting vascular endothelial growth factor expression.

A fruit fly model for studying paclitaxel-induced peripheral neuropathy and hyperalgesia

Background: Paclitaxel-induced peripheral neuropathy is a common and limiting side effect of an approved and effective chemotherapeutic agent. The cause of this nociception is still unknown. Methods: To uncover the mechanism involved in paclitaxel-induced pain, we developed a Drosophila thermal nociceptive model to show the effects of paclitaxel exposure on third instar larvae. Results: We found that paclitaxel increases heat nociception in a dose-dependent manner, and at the highest doses also obstructs dendritic repulsion cues. Conclusions: Our simple system can be applied to identify regulators of chemotherapy-induced pain and may help to eliminate pain-related side-effects of chemotherapy.

A fruit fly model for studying paclitaxel-induced pain

Background: Paclitaxel-induced peripheral neuropathy is a common and limiting side effect of an approved and effective chemotherapeutic agent. The cause of this nociception is still unknown. Methods: To uncover the mechanism involved in paclitaxel-induced pain, we developed a Drosophila thermal nociceptive model to show the effects of paclitaxel exposure on third instar larvae. Results: We found that paclitaxel increases pain perception in a dose-dependent manner, without overt morphological changes. Conclusions: Our simple, high throughput model can be combined with genomics approaches to identify regulators of chemotherapy-induced pain to eliminate its adverse side effects.

A review on the effects of current chemotherapy drugs and natural agents in treating non-small cell lung cancer

Lung cancer is the leading cause of cancer deaths worldwide, and this makes it an attractive disease to review and possibly improve therapeutic treatment options. Surgery, radiation, chemotherapy, targeted treatments, and immunotherapy separate or in combination are commonly used to treat lung cancer. However, these treatment types may cause different side effects, and chemotherapy-based regimens appear to have reached a therapeutic plateau. Hence, effective, better-tolerated treatments are needed to address and hopefully overcome this conundrum. Recent advances have enabled biologists to better investigate the potential use of natural compounds for the treatment or control of various cancerous diseases. For the past 30 years, natural compounds have been the pillar of chemotherapy. However, only a few compounds have been tested in cancerous patients and only partial evidence is available regarding their clinical effectiveness. Herein, we review the research on using current chemotherapy drugs and natural compounds (Wortmannin and Roscovitine, Cordyceps militaris, Resveratrol, OSU03013, Myricetin, Berberine, Antroquinonol) and the beneficial effects they have on various types of cancers including non-small cell lung cancer. Based on this literature review, we propose the use of these compounds along with chemotherapy drugs in patients with advanced and/or refractory solid tumours.

Regulatable Transgene Expression for Prevention of Chemotherapy-Induced Peripheral Neuropathy

Chemotherapy-induced peripheral neuropathy (CIPN) is a debilitating complication associated with drug treatment of cancer for which there are no effective strategies of prevention or treatment. In this study, we examined the effect of intermittent expression of neurotophin-3 (NT-3) or interleukin-10 (IL-10) from replication-defective herpes simplex virus (HSV)-based regulatable vectors delivered by subcutaneous inoculation to the dorsal root ganglion (DRG) on the development of paclitaxel-induced peripheral neuropathy. We constructed two different tetracycline (tet)-on-based regulatable HSV vectors, one expressing NT-3 and the other expressing IL-10, in which the transactivator expression in the tet-on system was under the control of HSV latency-associated promoter 2 (LAP-2), and expression of the transgene was controlled by doxycycline (DOX). We examined the therapeutic effect of intermittent expression of the transgene in animals with paclitaxel-induced peripheral neuropathy modeled by intraperitoneal injection of paclitaxel (16 mg/kg) once a week for 5 weeks. Intermittent expression of either NT-3 or IL-10 3 days before and 1 day after paclitaxel administration protected animals against paclitaxel-induced peripheral neuropathy over the course of 5 weeks. These results suggest the potential of regulatable vectors for prevention of chemotherapy-induced peripheral neuropathy.

miR-30a-5p enhances paclitaxel sensitivity in non-small cell lung cancer through targeting BCL-2 expression

Lung cancer remains the leading cause of cancer-related death worldwide. Paclitaxel, either as monotherapy or combined with other agents, is the standard treatment for advanced non-small cell lung cancer (NSCLC), the most common type of lung cancer. However, both de novo and acquired resistance against paclitaxel frequently occurs and represents a huge clinical problem. The underlying mechanisms remain poorly characterized. Here, by comparing microRNA (miRNA) expression levels using miRNA arrays, we observed differential expression of miR-30a-5p in two independent lung cancer cell pairs (paclitaxel-resistant vs paclitaxel-sensitive A549 cell lines). Overexpression of miR-30a-5p sensitizes NSCLC cells to paclitaxel both in vitro and in vivo. In addition, miR-30a-5p increases paclitaxel sensitivity by promoting chemotherapy-induced apoptosis via downregulating BCL-2, a key apoptosis regulator. High miR-30a-5p expression is positively correlated with enhanced responsiveness to paclitaxel and predicts a more favorable clinical outcome in NSCLC patients. Moreover, miR-30a-5p expression is negatively correlated with BCL-2 expression in NSCLC tissues. These data indicate that miR-30a-5p may be useful to treat paclitaxel-resistant lung cancer and may also provide a biomarker to predict paclitaxel responsiveness in lung cancer.

KEY MESSAGES

BCL-2 is a novel direct target of miR-30a-5p. miR-30a-5p enhances NSCLC paclitaxel sensitivity in vitro and in vivo. miR-30a-5p sensitizes NSCLC cells to paclitaxel by inducing apoptosis through BCL-2 inhibition. miR-30a-5p negatively correlates with BCL-2 and predicts a favorable clinical outcome in NSCLC patients.

Chemotherapy for Advanced Non-small Cell Lung Cancer

Non-small cell lung cancer has seen an unprecedented augmentation of therapeutic options over the last couple of years. Improved understanding of molecular drivers and the role of the immune system in cancer therapy have brought new drugs to the armamentarium. Despite these advances, cytotoxic chemotherapy remains a substantial part of therapy for most patients in locally advanced and metastatic stage. Initially thought to be a chemotherapy-resistant entity, meta-analyses in the mid-1990s demonstrated modest efficacy of platinum-based therapy. Further combination trials demonstrated enhanced efficacy for several regimen in first and second lines, including the introduction of antimetabolites, taxanes, and anti-angiogenic agents. Maintenance chemotherapy has been another novel, successful approach for management of metastatic disease. Herein, we summarize the current concepts of chemotherapy, its applicability to the different histologies, and novel concepts of therapy.

PRONOUNCE: randomized, open-label, phase III study of first-line pemetrexed + carboplatin followed by maintenance pemetrexed versus paclitaxel + carboplatin + bevacizumab followed by maintenance bevacizumab in patients ith advanced nonsquamous non-small-cell lung cancer

INTRODUCTION

PRONOUNCE compared the efficacy and safety of pemetrexed+carboplatin followed by pemetrexed (Pem+Cb) with paclitaxel+carboplatin+bevacizumab followed by bevacizumab (Pac+Cb+Bev) in patients with advanced nonsquamous non-small-cell lung cancer (NSCLC).

METHODS

Patients ≥18 years of age with stage IV nonsquamous NSCLC (American Joint Committee on Cancer v7.0), and Eastern Cooperative Oncology Group performance status 0/1 were randomized (1:1) to four cycles of induction Pem+Cb (pemetrexed, 500 mg/m, carboplatin, area under the curve = 6) followed by Pem maintenance or Pac+Cb+Bev (paclitaxel, 200 mg/m, carboplatin, area under the curve = 6, and bevacizumab, 15 mg/kg) followed by Bev maintenance in the absence of progressive disease or discontinuation. The primary objective was progression-free survival (PFS) without grade 4 toxicity (G4PFS). Secondary end points were PFS, overall survival (OS), overall response rate (ORR), disease control rate (DCR), and safety. Resource utilization was also assessed.

RESULTS

Baseline characteristics of the patients randomized to Pem+Cb (N = 182) and Pac+Cb+Bev (N = 179) were well balanced between the arms. Median (months) G4PFS was 3.91 for Pem+Cb and 2.86 for Pac+Cb+Bev (hazard ratio = 0.85, 90% confidence interval, 0.7-1.04; p = 0.176); PFS, OS, ORR, or DCR did not differ significantly between the arms. Significantly more drug-related grade 3/4 anemia (18.7% versus 5.4%) and thrombocytopenia (24.0% versus 9.6%) were reported for Pem+Cb. Significantly more grade 3/4 neutropenia (48.8% versus 24.6%), grade 1/2 alopecia (28.3% versus 8.2%), and grade 1/2 sensory neuropathy were reported for Pac+Cb+Bev. Number of hospitalizations and overall length of stay did not differ significantly between the arms.

CONCLUSIONS

Pem+Cb did not produce significantly better G4PFS compared with Pac+Cb+Bev. Pem+Cb was not superior in PFS, OS, ORR, or DCR compared with Pac+Cb+Bev. Both regimens were well tolerated, although, toxicity profiles differed.

Non-adherent culture induces paclitaxel resistance in H460 lung cancer cells via ERK-mediated up-regulation of βIVa-tubulin

Circulating tumor cells (CTCs) are metastasizing epithelial cancer cells that adapt to survive when floating in bloodstream during metastasis. This condition can be mimicked in vitro by using non-adherent cell culture. The chemosensitivity of CTCs appears to correlate with the response of metastatic cancer patients to therapy, but chemoresistance is also frequently observed in advanced stage cancer patients, who have never previously received chemotherapy. We hypothesize that adaptation of epithelial cancer cells to become floating CTCs could lead to development of chemoresistance. Here, we explore whether chemoresistance is induced in epithelial cancer cells when cultured under non-adherent conditions. Increased paclitaxel-specific resistance was observed in floating cells compared to attached cells in H460, MCF-7, and HepG2 human cancer cell lines, by 15.6-, 3.9-, and 2.6-fold increases in IC50 values, respectively. qRT-PCR analysis showed that a paclitaxel-resistant β-tubulin isotype, βIVa-tubulin, was the most up-regulated gene compared with other β-tubulin isotypes in H460 floating cells, concomitant with elevated ERK activation. ERK inhibitor treatment could attenuate the up-regulation of βIVa-tubulin, and decreased the paclitaxel resistance of H460 floating cells, even though other β-tubulin isotypes were up-regulated when the ERK activation was blocked. In conclusion, we show induction of paclitaxel resistance in epithelial cancer cells, when floating in non-adherent culture, and this might occur with CTCs of cancer patients.

Taxanes, past, present, and future impact on non-small cell lung cancer

Taxanes are novel microtubule-stabilizing agents and have shown efficacy in non-small cell lung cancer (NSCLC) since the 1990s. Paclitaxel and docetaxel have been used either as single agents or in combination with a platinum compound. The newer generation albumin-bound taxane, nab-paclitaxel, has also shown similar efficacy in advanced NSCLC, both as a single agent and in combination with a platinum compound. Nab-paclitaxel, being Cremophor EL free, appears to have a better toxicity profile than paclitaxel. Taxane/platinum combinations still remain the foundation of treatment for advanced or metastatic NSCLC. Docetaxel and paclitaxel as single agents have also shown efficacy in the second-line setting in advanced/metastatic NSCLC. Oral formulations of paclitaxel and docetaxel are of great interest, but have yet to receive regulatory approval in this disease. The phase I-II trials have shown that these formulations are feasible in the clinical setting.

Antiviral activity of (+)-rutamarin against Kaposi's sarcoma-associated herpesvirus by inhibition of the catalytic activity of human topoisomerase II

Kaposi's sarcoma-associated herpesvirus (KSHV) is an etiological agent of several AIDS-associated malignancies, including Kaposi's sarcoma (KS), primary effusion lymphoma (PEL), and multicentric Castleman's disease (MCD). Its lytic replication cycle has been proven to be critical for the pathogenesis of KSHV-associated diseases. In KS lesions, lytic viral replication, production of virion particles, and reinfection of endothelial cells are essential to sustain the population of infected cells that otherwise would be quickly lost as spindle cells divide. Thus, antivirals that block KSHV replication could be a strategy in the treatment of KSHV-associated diseases. However, there is no effective anti-KSHV drug currently available. Our previous work showed that human topoisomerase II (Topo II) is indispensable for KSHV lytic replication and is suggested to be an effective target for antiviral drugs. Here, we report the discovery and characterization of a novel catalytic inhibitor of human Topo IIα, namely, (+)-rutamarin. The binding mode of (+)-rutamarin to the ATPase domain of human Topo IIα was established by docking and validated by molecular dynamics (MD) simulations. More importantly, (+)-rutamarin efficiently inhibits KSHV lytic DNA replication in BCBL-1 cells with a half-maximal inhibitory concentration (IC50) of 1.12 μM and blocks virion production with a half-maximal antiviral effective concentration (EC50) of 1.62 μM. It possesses low cytotoxicity, as indicated by the selectivity index (SI) of 84.14. This study demonstrated great potential for (+)-rutamarin to become an effective drug for treatment of human diseases associated with KSHV infection.

A CDK4/6 inhibitor enhances cytotoxicity of paclitaxel in lung adenocarcinoma cells harboring mutant KRAS as well as wild-type KRAS

The KRAS gain-of-function mutation confers intrinsic resistance to targeted anti-cancer drugs and cytotoxic chemotherapeutic agents, ultimately leading to treatment failure. KRAS mutation frequency in lung adenocarcinoma is ~15–30%. Novel therapeutic strategies should be developed to improve clinical outcomes in these cases. Deregulation of the p16/cyclin-dependent kinase (CDK) 4/retinoblastoma (Rb) pathway is frequently observed in various cancers and it represents an attractive therapeutic target. We compared the anti-tumor efficacy of genetically knocked-down CDK4 and a pharmacological inhibitor of CDK4/6, CINK4, in KRAS mutation-positive lung adenocarcinoma cells. We also investigated changes in anti-proliferative activity and downstream molecules with these treatments in combination with paclitaxel. CDK4 short interfering RNA (siRNA) significantly increased paclitaxel sensitivity in KRAS mutation-positive H23 cells. CINK4 demonstrated concentration- and time-dependent anti-proliferative activity in 5 adenocarcinoma lines. CINK4 induced G₁ arrest by downregulating the p16/cyclin D1/Rb pathway, resulting in apoptotic induction via increased expression of cleaved caspase3, cleaved PARP and Bax. Combined CINK4 and paclitaxel produced synergistic anti-proliferative activity and increased apoptosis through reduced cyclin D1 and Bcl-2 in KRAS mutation-positive cancer cells. These data suggest CDK4 is a promising target for development of anti-cancer drugs and CINK4 combined with paclitaxel may be an effective therapeutic strategy for enhancing anti-tumor efficacy in KRAS mutation-positive lung adenocarcinoma.

miR-337-3p and its targets STAT3 and RAP1A modulate taxane sensitivity in non-small cell lung cancers

NSCLC (non-small cell lung cancer) often exhibits resistance to paclitaxel treatment. Identifying the elements regulating paclitaxel response will advance efforts to overcome such resistance in NSCLC therapy. Using in vitro approaches, we demonstrated that over-expression of the microRNA miR-337-3p sensitizes NCI-H1155 cells to paclitaxel, and that miR-337-3p mimic has a general effect on paclitaxel response in NSCLC cell lines, which may provide a novel adjuvant strategy to paclitaxel in the treatment of lung cancer. By combining in vitro and in silico approaches, we identified STAT3 and RAP1A as direct targets that mediate the effect of miR-337-3p on paclitaxel sensitivity. Further investigation showed that miR-337-3p mimic also sensitizes cells to docetaxel, another member of the taxane family, and that STAT3 levels are significantly correlated with taxane resistance in lung cancer cell lines, suggesting that endogenous STAT3 expression is a determinant of intrinsic taxane resistance in lung cancer. The identification of a miR-337-3p as a modulator of cellular response to taxanes, and STAT3 and RAP1A as regulatory targets which mediate that response, defines a novel regulatory pathway modulating paclitaxel sensitivity in lung cancer cells, which may provide novel adjuvant strategies along with paclitaxel in the treatment of lung cancer and may also provide biomarkers for predicting paclitaxel response in NSCLC.

Phase II multi-institutional prospective randomised trial comparing S-1+paclitaxel with S-1+cisplatin in patients with unresectable and/or recurrent advanced gastric cancer

Background:

A combination of S-1 and cisplatin has been shown to be effective with acceptable safety for the first-line treatment of far-advanced gastric cancer in Japan. This is the first randomised phase II trial to compare S-1+paclitaxel with S-1+cisplatin in this setting.

Methods:

Patients with unresectable and/or recurrent advanced gastric cancer were randomly assigned to receive one of the two regimens: S-1 (40 mg m⁻² twice daily) on days 1–14 plus paclitaxel (60 mg m⁻²) on days 1, 8, and 15 of a 4-week cycle (S-1+paclitaxel) or S-1 (40 mg m⁻² twice daily) on days 1–21 plus cisplatin (60 mg m⁻²) on day 8 of a 5-week cycle (S-1+cisplatin). The primary end point was the response rate (RR). Secondary end points included progression-free survival (PFS), overall survival (OS), and safety.

Results:

A total of 83 patients were eligible for safety and efficacy analyses. In the S-1+paclitaxel and S-1+cisplatin groups, RRs (52.3% vs 48.7% P=0.74) and median PFS (9 vs 6 months; P=0.50) were similar. The median OS was similar in the S-1+paclitaxel and S-1+cisplatin groups (16 vs 17 months; P=0.84). The incidence of grade 3 or higher haematological toxicity was 19.0% with S-1+paclitaxel and 19.5% with S-1+cisplatin. The incidence of grade 3 or higher non-haematological toxicity was 14.2% with S-1+paclitaxel and 17.1% with S-1+cisplatin.

Conclusion:

S-1+paclitaxel was suggested to be a feasible and effective non-platinum-based regimen for chemotherapy in patients with advanced gastric cancer. Our results should be confirmed in multicenter, phase III-controlled clinical trials.

A novel bioluminescence orthotopic mouse model for advanced lung cancer

Lung cancer is the leading cause of cancer-related death in the United States despite recent advances in our understanding of this challenging disease. An animal model for high-throughput screening of therapeutic agents for advanced lung cancer could help promote the development of more successful treatment interventions. To develop our orthotopic lung cancer model, luciferase-expressing A549 cancer cells were injected into the mediastinum of athymic nude mice. To determine whether the model would allow easy monitoring of response to therapeutic interventions, tumors were treated with 30 mg/kg Paclitaxel or were irradiated with 5 fractions of 2 Gy, and tumor burden was monitored using bioluminescence imaging. Evidence of radiation-induced lung injury was assessed using immunohistochemical staining for phospho-Smad2/3 and cleaved caspase-3. We found that tumor implantation recapitulated advanced human lung cancer as evidenced by tumor establishment and proliferation within the mediastinum. The tumor responded to Paclitaxel or radiation as shown by decreased tumor bioluminescence and improved overall survival. Immunohistochemistry revealed increased phospho-Smad2/3 and cleaved caspase-3 in irradiated lungs, consistent with radiation-induced lung injury. This orthotopic lung cancer model may help provide a method to assess therapeutic interventions in a preclinical setting that recapitulates locally advanced lung cancer.

Phase I Trial of Concurrent Hyperfractionated Split Course Radiotherapy (HFx RT), Cisplatin (cDDP), and Paclitaxel in Patients with Recurrent, Previously Irradiated, or Treatment-Naïve Locally Advanced Upper Aerodigestive Malignancy

PURPOSE

Phase I study to determine the maximally tolerated dose (MTD) of cisplatin (cDDP), paclitaxel (P), and concurrent split course hyperfractionated (BID) RT in advanced squamous cell carcinoma of the head and neck (SCCHN) and other upper aerodigestive tumors.

MATERIALS AND METHODS

Eligibility stipulated ECOG performance status 0-2 and either Tx-naïve, locally advanced, or locally recurrent, previously radiated, surgically unresectable upper aerodigestive cancer. Metastases were permitted if disease was predominantly locoregional. RT-naïve patients received 150 cGy bid x 5 d Q 2 wks x 4. Previously radiated patients received 150 cGy bid x 5, wk 1; then 120 cGy bid x 5 Q 2 wk x 3 (later increased to 150 cGy BID for the entire treatment). Treatment fields included recurrent tumor only with 2 cm margins. Whenever possible, conventional and 3-D conformal techniques were used. Elective nodal radiation was not administered. Starting doses of cDDP and P were 12 mg/m2/d x 5 and 15 mg/m2/d x 5, respectively, Q 2 wk x 4, each given on RT days only. At dose level 2, cDDP was increased to 15 mg/m2/d x 5. At dose level 3, P was increased to 20 mg/m2/d x 5. Granulocyte colony stimulating factor (G-CSF) days 6-12 (off treatment week) was added if cumulative neutropenia precipitated treatment delays.

RESULTS

Thirty-one patients (21 men, 10 women) were treated. Eight had received prior chemotherapy, 27 prior RT. At dose level three, regular treatment delays of >or=1 week due to slow neutrophil recovery occurred. Addition of G-CSF (dose level 3b) reduced treatment delays from 100 percent to 28 percent and decreased the incidence of Grade >or=2 neutropenia and mucositis. Six of 7 patients at this dose level completed all 4 cycles of treatment and all received full dose RT (60 Gy). No other dose-limiting toxicities occurred. Of 22 assessable patients with locally recurrent SCCHN, 12 (55 percent) responded. Median time to progression in this group was 6 months, with median and one-year survival of 9.5 mos and 41 percent, respectively.

CONCLUSION

Concurrent daily cisplatin/paclitaxel and split course hyperfractionated RT (60 Gy) is feasible in previously radiated patients. G-CSF, administered between each cycle, reduces the incidence of treatment delays. Activity is promising and toxicity acceptable.

Phase II study of weekly paclitaxel by one-hour infusion for advanced gastric cancer

PURPOSE

A phase clinical II trial was conducted to determine the antitumor activity and toxicity of weekly paclitaxel administered to patients with advanced gastric cancer.

METHODS

Sixty-eight patients with advanced gastric cancer and performance status 0-2 were treated with 80 mg/m2 paclitaxel over 1 h following a short course of premedication with dexamethasone, diphenhydramine, and ranitidine administered 30 min prior to the delivery of the paclitaxel. In principle, the treatment was repeated weekly for three courses, followed by a 1-week rest.

RESULTS

Objective responses were observed in 12 of 68 patients (17.6%; 95% confidence interval: 9.5%-28.8%). Two of fourteen (14.2%) patients with no prior chemotherapy and 10 of 54 (18.5%) patients previously treated for metastatic disease developed a partial response. The median therapeutic duration and the median survival time were 96 days and 222 days, respectively. In 212 (85.5%) of 248 total cycles, the original dose of 80 mg/m2 of paclitaxel was administered and was well tolerated. Fourteen of 68 patients (20.1%) experienced grade 3 or 4 neutropenia. Grade 1 or 2 peripheral neuropathy occurred in 10 patients (14.7%).

CONCLUSION

Weekly paclitaxel therapy is an active and safe treatment for advanced gastric cancer.

Different tissue distribution of paclitaxel with intravenous and intraperitoneal administration

PURPOSE

Paclitaxel is considered to be suitable for disseminated cancer in the peritoneal cavity because of its high molecular weight and lipophilic characteristics. However, the difference in pharmacokinetics of paclitaxel after intraperitoneal (i.p.) and intravenous (i.v.) administration is not fully defined. Here, we investigated the tissue concentration of paclitaxel in various organs at various time points after i.p. or i.v. administration.

METHODS

Paclitaxel (5 mg/kg) was administrated in an ear vein or in the abdominal cavity of rabbits. At 0.5, 6, 24, and 48 h after administration, the rabbits were sacrificed, and organs as well as peripheral blood were harvested. The serum and tissue concentrations of paclitaxel were measured by HPLC procedure.

RESULT

The concentration of paclitaxel was high in the i.v. group at 0.5 h, whereas it was significantly higher in the i.p. group at 6 and 24 h. The AUC (area under the curve) was markedly higher in the omentum, mesenteric lymph nodes as well as ovary and stomach in the i.p. group.

CONCLUSION

Compared with i.v. administration, paclitaxel concentration was maintained at a high level in the whole body by i.p. administration. Repeated i.p. paclitaxel can produce more marked clinical effects than i.v. administration for metastatic lymph nodes and primary lesions as well as peritoneal dissemination.

A phase i study of bolus 5-fluorouracil and leucovorin combined with weekly paclitaxel (FLTAX) as first-line therapy for advanced gastric cancer

OBJECTIVE

To determine the dose-limiting toxicity (DLT) and the maximum-tolerated dose (MTD) of combination chemotherapy with leucovorin-modulated weekly bolus 5-fluorouracil (5-FU) and weekly paclitaxel in patients with advanced gastric cancer (GC).

METHODS

Chemotherapy-naive patients with histologically proven metastatic or recurrent GC were enrolled. Paclitaxel was administered as a 1-h intravenous (i.v.) infusion followed by 5-FU as a bolus i.v. infusion on Days 1, 8 and 15. A 2-h i.v. infusion of l-leucovorin was started at the same time as the paclitaxel infusion on Days 1, 8 and 15. Treatment cycles were repeated every 28 days until disease progression or unacceptable toxicity occurred. Patients were scheduled to receive 5-FU, l-leucovorin and paclitaxel at four dose levels (mg/m(2)/week): 500/250/60 (level 1), 500/250/80 (level 2), 600/250/80 (level 3) and 600/250/100 (level 4), respectively.

RESULTS

Eighteen patients were enrolled. During the first cycle of the highest dose level (level 4), two of the six patients had DLT involving Grade 3 diarrhea and Grade 3 skin rash. Furthermore, three of the four patients who received the second consecutive cycle of treatment at dose level 4 had Grade 4 neutropenia. Dose level 3 was thus determined to be the MTD. Eleven (61%) of the 18 patients had partial responses, and the median progression-free survival time was 6.8 months.

CONCLUSIONS

The MTD and the recommended dose for phase II studies of this regimen were determined to be 5-FU 600 mg/m(2)/week, l-leucovorin 250 mg/m(2)/week and paclitaxel 80 mg/m(2)/week.

Phase I/II study of a combination of S-1 and weekly paclitaxel in patients with advanced or recurrent gastric cancer

OBJECTIVE

A phase I/II study of a combination of S-1 and weekly paclitaxel was conducted to determine the maximum tolerated dose (MTD), recommended dose (RD), dose-limiting toxicities (DLTs) and objective response rate (RR) in patients with advanced or recurrent gastric cancer.

METHODS

S-1 was administered orally at a fixed dose of 80 mg/m(2) per day on days 1-14. Paclitaxel was injected intravenously on days 1, 8, and 15, starting with a dose of 50 mg/m(2). The dose was increased in a stepwise manner.

RESULTS

In phase I, level 2 (60 mg/m(2)) was considered the MTD, because 2 of 3 patients in level 2 developed DLTs (grade 3 neutropenia and anemia, and grade 4 diarrhea and stomatitis). Therefore, the RD was determined to be level 1 (50 mg/m(2)). In phase II, efficacy and safety were assessed in 18 patients treated with the RD. The RR was 64.7% and the median survival time was 13.5 months. The most severe toxicities were grade 3 leukopenia (5.5%) and grade 3 neutropenia (5.5%).

CONCLUSION

Our study showed that S-1 combined with 50 mg/m(2) paclitaxel is effective and safe in patients with advanced or recurrent gastric cancer.

A novel triplet regimen with paclitaxel, carboplatin and gemcitabine (PACCAGE) as induction chemotherapy for locally advanced unresectable non small cell lung cancer (NSCLC)

Phase II study of 3 cycles of triplet induction chemotherapy (response, toxicity) followed by radiotherapy in locally advanced non small cell lung cancer (NSCLC).

BACKGROUND

Patients with locally advanced inoperable non-small cell lung cancer are currently treated with concomitant or sequential chemotherapy and radiotherapy. However, the outcome of existing treatment modalities is unsatisfactory. Development of new strategies including more efficient systemic chemotherapy is warranted.

OBJECTIVE

To study the antitumour activity and toxicity of a triplet combination of paclitaxel, carboplatin and gemcitabine as induction chemotherapy before radiotherapy, in locally advanced NSCLC and to evaluate time to progression and survival.

METHODS

Three cycles of paclitaxel (175 mg/m(2) by 3h infusion on day 1), carboplatin (AUC 5mg/(mlmin) by IV bolus on day 1) and gemcitabine (1000 mg/m(2) by IV bolus on day 1 and 8) were administered every 3 weeks in reasonably fit patients. Fractionated radiotherapy with curative intent was initiated 4 weeks after the last chemotherapy administration. Toxicity was assessed weekly during cycle 1 and on day 1 and 8 in cycles 2 and 3. Response evaluation was performed at the end of cycle 3.

RESULTS

Forty-eight patients (20 stage IIIA and 28 stage IIIB) received a total of 134 cycles of chemotherapy. Forty-two patients received the intended 3 cycles. Thirty patients obtained an objective response (1 complete and 29 partial response) or 62.5% on the intent to treat analysis (95% confidence interval: 49-76%). None of the responders became eligible for surgery. The median time to progression and survival for all patients was 10.1 and 15.7 month, respectively. A significant difference was observed in survival parameters between stage IIIA and stage IIIB patients. Haematological toxicity grade 3/4, mainly neutropenia and thrombocytopenia, was most prominent on day 15 of the treatment cycles. Haematological support by means of recombinant erythropoietin, red blood cell or platelet transfusion, filgrastim administration or a combination was needed in 21 patients. None of the patients discontinued chemotherapy because of haematotoxicity. Grade 3/4 non-haematological toxicity leading to chemotherapy withdrawal occurred early during induction (2 and 1 in cycles 1 and 2, respectively).

CONCLUSION

Three cycles of the novel triplet combination of paclitaxel, carboplatin and gemcitabine (PACCAGE) is an active and feasible induction regimen for patients with locally advanced inoperable NSCLC. Neutropenia and to a lesser extent thrombocytopenia represent the main haematological toxicity. Whether this triplet regimen can improve outcome when compared to specific cisplatin doublet regimens should be evaluated in a phase III study.

A novel polymer–paclitaxel conjugate based on amphiphilic triblock copolymer

A novel amphiphilic polymer-paclitaxel conjugate P(LGG-paclitaxel)-PEG-P(LGG-paclitaxel) has been prepared. It was derived from its parent polymer P(LGG)-PEG-P(LGG), poly{(lactic acid)-co-[(glycolic acid)-alt-(l-glutamic acid)]}-block-poly(ethylene glycol)-block-poly{(lactic acid)-co-[(glycolic acid)-alt-(l-glutamic acid)]}, which was prepared by ring-opening copolymerization of l-lactide (LLA) with (3s)-benzoxylcarbonylethyl-morpholine-2,5-dione (BEMD) in the presence of dihydroxyl PEG with molecular weight of 4600 as a macroinitiator using stannous octoate (Sn(Oct)(2)) as catalyst, and by subsequent catalytic hydrogenation. It could self-assemble into micelles in an aqueous system with P(LGG-paclitaxel) block in the core and PEG in the shell. ESEM and DLS analysis of the micelles revealed a homogeneous spherical morphology and a unimodal size distribution. In vitro release of paclitaxel from the conjugate micelles showed that its release rate depended on pH value and was higher at lower pH than in neutral condition. In vitro antitumor activity of the paclitaxel conjugate against rat brain glioma C6 cells was evaluated by MTT method. The results showed that the paclitaxel can be released from the conjugate without losing cytotoxicity.

Phase I/II study of S-1 combined with paclitaxel in patients with unresectable and/or recurrent advanced gastric cancer

Both paclitaxel and S-1 are effective against gastric cancer, but the optimal regimen for combined chemotherapy with these drugs remains unclear. This phase I/II study was designed to determine the maximum tolerated dose (MTD), recommended dose (RD), dose-limiting toxicity (DLT), and objective response rate of paclitaxel in combination with S-1. S-1 was administered orally at a fixed dose of 80 mg m-2 day-1 from days 1 to 14 of a 28-day cycle. Paclitaxel was given intravenously on days 1, 8, and 15, starting with a dose of 40 mg m-2 day-1. The dose was increased in a stepwise manner to 70 mg m-2. Treatment was repeated every 4 weeks unless disease progression was confirmed. In the phase I portion, 17 patients were enrolled. The MTD of paclitaxel was estimated to be 70 mg m-2 because 40% of the patients given this dose level (two of five) had DLT. The RD was determined to be 60 mg m-2. In the phase II portion, 24 patients, including five with assessable disease who received the RD in the phase I portion, were evaluated. The median number of treatment courses was six (range: 1-17). The incidence of the worst-grade toxicity in patients given the RD was 28 and 8%, respectively. All toxic effects were manageable. The response rate was 54.1%, and the median survival time was 15.5 months. Our phase I/II trial showed that S-1 combined with paclitaxel is effective and well tolerated in patients with advanced gastric cancer.

Changes in the natural history of nonsmall cell lung cancer (NSCLC)--comparison of outcomes and characteristics in patients with advanced NSCLC entered in Eastern Cooperative Oncology Group trials before and after 1990

BACKGROUND

Demographic factors and treatment regimens were evaluated in relation to differences in outcome between patients with advanced nonsmall cell lung cancer (NSCLC) who were diagnosed and treated on Eastern Cooperative Oncology Group Phase II and III trials from 1981 to 1990 and from 1991 to 2000.

METHODS

In this retrospective analysis, 6 advanced NSCLC trials were identified between 1981 and 1990, and 3 trials were identified after 1990. Patient characteristics (n = 3398 patients) and other clinical outcomes were analyzed, including progression-free survival (PFS) and overall survival (OS).

RESULTS

Patients who entered on trials after 1990 more likely were women, received a cisplatin-containing regimen, had a performance status of 0 or 1, had Stage IIIB (vs. Stage IV) disease, had tumors with adenocarcinoma histology, had weight loss < or = 10%, and had pulmonary-only metastases (although more total metastases and brain metastases) compared with patients who were diagnosed before 1990. OS was longer post-1990 than pre-1990 (8.2 months vs. 5.8 months pre-1990), and PFS was longer post-1990 (3.5 months vs. 2.6 months pre-1990; P<.001 for both). In addition, the median interval from the date of disease progression to death increased by nearly 62% in the later decade.

CONCLUSIONS

Improved survival in more recent NSCLC trials was explained in part by the enrollment of patients with more favorable prognostic factors. A change in the natural history of the disease was reflected by some of these changes, including increased numbers of women with the disease and changes in the patterns of metastases. Changes in eligibility criteria also accounted for some improvements in prognostic factors and improved second line therapies in the later decade. Thus, the survival improvements are likely to be multifactorial, with improved therapies also playing a major role.

Phase II trial of weekly paclitaxel and gemcitabine for previously untreated, stage IIIB-IV nonsmall cell lung cancer

BACKGROUND

The purpose of the current study was to evaluate the efficacy and tolerance of the noncisplatin-based combination of paclitaxel and gemcitabine administered weekly for patients with untreated metastatic nonsmall cell lung cancer (NSCLC).

METHODS

Patients with Stage IIIB/IV or recurrent NSCLC, a performance status of 0-2, and no prior chemotherapy exposure were eligible. Patients received gemcitabine 1000 mg/m2 and paclitaxel 85 mg/m2 on Days 1, 8, 15, 22, 29, 36 of an 8-week cycle until progression.

RESULTS

Thirty-nine eligible patients were enrolled. The median age was 66 years and 14 patients were > or =70 years old. Performance status was 2 in 13 (33%) and 29 patients (75%) had Stage IV. Five patients (12.8%) developed interstitial pneumonitis and 2 of these were responsive to steroid therapy. The overall response rate was 23.1%, with no complete responses. The median survival was 32 weeks and the 1-year survival was 32%.

CONCLUSIONS

This regimen of weekly paclitaxel and gemcitabine has modest activity in advanced NSCLC.