Design, synthesis and in vitro drug release investigation of new potential 5-FU prodrugs

Self-assembled 5-fluorouracil-cinnamaldehyde nanodrugs for greatly improved chemotherapy in vivo

The preferred cancer treatment is to achieve a high therapeutic effect as well as reduce side effects. In this study, we developed carrier-free nano drugs based on 5-fluorouracil (5FU) and cinnamaldehyde (CA) to meet the above goals. Two model drugs were spliced by acetal linkage and ester bond, which could self-assemble into nano drug particles (5FU-CA NPs) with a size of ∼170 nm. In vitro cell experiments showed 5FU-CA NPs were efficiently internalized by HepG2 cells. They then quickly exerted dual drug activities by the cleavage of acetal and ester bond, resulting in enhanced cell-killing efficacy and apoptosis. Synergistic mechanisms were achieved via the anti-metabolic effects mediated by 5FU-COOH and the oxidative damage induced by CA. In vivo anti-tumor evaluation further indicated that 5FU-CA NPs had higher tumor growth inhibition than 5FU-COOH/CA mixture (5FU-COOH + CA) and exhibited lower systemic toxicity under the same reducing dose of each drug. Overall, this is a successful synergistic anti-tumor attempt through rational self-assembly of drugs with different mechanisms and it can be extrapolated to other agents.

Targeted delivery of 5-fluorouracil-1-acetic acid (5-FA) to cancer cells overexpressing epithelial growth factor receptor (EGFR) using virus-like nanoparticles

Chemotherapy is widely used in cancer treatments. However, non-specific distribution of chemotherapeutic agents to healthy tissues and normal cells in the human body always leads to adverse side effects and disappointing therapeutic outcomes. Therefore, the main aim of this study was to develop a targeted drug delivery system based on the hepatitis B virus-like nanoparticle (VLNP) for specific delivery of 5-fluorouracil-1-acetic acid (5-FA) to cancer cells expressing epithelial growth factor receptor (EGFR). 5-FA was synthesized from 5-fluorouracil (5-FU), and it was found to be less toxic than the latter in cancer cells expressing different levels of EGFR. The cytotoxicity of 5-FA increased significantly after being conjugated on the VLNP. A cell penetrating peptide (CPP) of EGFR was displayed on the VLNP via the nanoglue concept, for targeted delivery of 5-FA to A431, HT29 and HeLa cells. The results showed that the VLNP displaying the CPP and harboring 5-FA internalized the cancer cells and killed them in an EGFR-dependent manner. This study demonstrated that the VLNP can be used to deliver chemically modified 5-FU derivatives to cancer cells overexpressing EGFR, expanding the applications of the VLNP in targeted delivery of chemotherapeutic agents to cancer cells overexpressing this transmembrane receptor.

Linker structure-activity relationships in fluorodeoxyglucose chlorambucil conjugates for tumor-targeted chemotherapy

Nitrogen mustards, such as chlorambucil (CLB), can cause adverse side-effects due to ubiquitous distribution in non-target organs. To minimize this toxicity, strategies of tumor-targeting drug delivery have been developed, where a cytotoxic warhead is linked to a tumor-cell-specific small ligand. Malignant cells exhibit marked glucose avidity and an accelerated metabolism by aerobic glycolysis, known as the Warburg effect, and recognized as a hallmark of cancer. A targeting approach exploiting the Warburg effect by conjugation of CLB to 2-fluoro-2-deoxyglucose (FDG) was previously reported and identified two peracetylated glucoconjugates 2 and 3 with promising antitumor activities in vivo. These results prompted us to investigate the importance of the spacer in this tumor-targeting glucose-based conjugates. Here we report the chemical synthesis and an in vitro cytotoxicity evaluation, using a 5-member panel of human tumor cell lines and human fibroblasts, of 16 new CLB glucoconjugates in which the alkylating drug is attached to the C-1 position of FDG via different linkages. We studied the structure-activity relationships in the linker, and evidenced the positive impact of an aromatic linker on in vitro cytotoxicity: compound 51 proved to be the most active FDG-CLB glucoside, characterized by a bis-aromatic spacer tethered to CLB through an amide function.

5-Fluorouracil derivatives: a patent review (2012 - 2014)

INTRODUCTION

5-Fluorouracil (5-FU)-based chemotherapy is the most widely prescribed treatment for gastrointestinal solid tumors, but there are several drawbacks such as toxicities, lack of selectivity and effectiveness as well as the development of resistance that need to be overcome.

AREAS COVERED

In this review, the authors present the latest innovations in 5-FU derivatives or combinations with: i) other chemotherapeutic drugs; ii) novel targeted compounds; iii) radiotherapy; iv) mAbs; v) siRNA strategies; and vi) traditional Chinese medicine extracts. Moreover, advances to overcome or determine 5-FU adverse effects and effectiveness are described. Finally, the authors introduce the ongoing clinical trials and highlight the main challenges to be addressed in the future.

EXPERT OPINION

Although in the past few years there has been a great advancement in the antitumor effectiveness and selectivity of 5-FU-based therapies, it is envisaged that future approaches using 'omics' technologies that could determine the tumor heterogeneity may help in identifying additional candidate genes, microRNAs or cytokines involved in both the path mechanisms of 5-FU-related toxicity and its therapeutic efficacy. Moreover, the development of novel targeted 5-FU derivatives or 5-FU-based therapies tailored to individual patients opens up new possibilities in the improvement of the quality of life and survival for those suffering from this devastating disease.

Design and synthesis of novel 5,6-disubstituted pyridine-2,3-dione-3-thiosemicarbazone derivatives as potential anticancer agents

A series of 5,6-disubstituted pyridine-2,3-dione-3-thiosemicarbazone derivatives(2a-2n) and 5,6-disubstituted pyridine-2,3-dione S-benzyl-3-thiosemicarbazones(3a-3g) were synthesized starting from 2,3-dihydroxypyridine via oxidation-Michael additions, condensations and nucleophilic substitutions. The structures of the compounds were established by IR, (1)H NMR, (13)C NMR, and HRMS. All newly synthesized compounds were screened for their anticancer activity against Breast cancer (MCF-7), Colon cancer (HCT-116) and hepatocellular cancer (BEL7402) cell lines. Bioassay results indicated that most of the prepared compounds exhibited cytotoxicity against various cancer cells in vitro. Some of the compounds exhibited promising antiproliferative activity, which were comparable to the positive control (5-fluorouracil). The structure-activity relationship was discussed.

Targeted cancer therapy with a 2-deoxyglucose-based adriamycin complex

Adriamycin (ADM) has been effective against many types of solid tumors in clinical applications. However, its use is limited because of systemic toxicities, primarily cardiotoxicity, and multidrug resistance. In this study, a new active receptor-mediated complex, ADM conjugated with 2-amino-2-deoxy-d-glucose and succinic acid (2DG-SUC-ADM), was designed to target tumor cells through glucose transporter 1 (GLUT1). MTT assay and confocal images showed that the complex had better inhibition rate to tumor cells and low toxicity to normal cells. Most importantly, the complex displayed a potential to reverse overcome multidrug resistance in cancer cells, with more complex transported into the nucleus of tumor cells. Our in vivo experiments also showed that this new complex could significantly decrease organ toxicity and enhance the antitumor efficacy compared with free ADM, indicating a promising drug of 2DG-SUC-ADM for targeted cancer therapy.

Analysis of anticancer drugs: a review

In the last decades, the number of patients receiving chemotherapy has considerably increased. Given the toxicity of cytotoxic agents to humans (not only for patients but also for healthcare professionals), the development of reliable analytical methods to analyse these compounds became necessary. From the discovery of new substances to patient administration, all pharmaceutical fields are concerned with the analysis of cytotoxic drugs. In this review, the use of methods to analyse cytotoxic agents in various matrices, such as pharmaceutical formulations and biological and environmental samples, is discussed. Thus, an overview of reported analytical methods for the determination of the most commonly used anticancer drugs is given.