A Phase Ib pharmacokinetic study of the anti-angiogenic agent CKD-732 used in combination with capecitabine and oxaliplatin (XELOX) in metastatic colorectal cancer patients who progressed on irinotecan-based chemotherapy. Invest New Drugs. 2012;30:672-680. [PMID: 21188464 DOI: 10.1007/s10637-010-9625-x]

Methionine aminopeptidases: Potential therapeutic target for microsporidia and other microbes

Methionine aminopeptidases (MetAPs) have emerged as a target for medicinal chemists in the quest for novel therapeutic agents for treating cancer, obesity, and other disorders. Methionine aminopeptidase is a metalloenzyme with two structurally distinct forms in humans, MetAP-1 and MetAP-2. The MetAP2 inhibitor fumagillin, which was used as an amebicide in the 1950s, has been used for the successful treatment of microsporidiosis in humans; however, it is no longer commercially available. Despite significant efforts and investments by many pharmaceutical companies, no new MetAP inhibitors have been approved for the clinic. Several lead compounds have been designed and synthesized by researchers as potential inhibitors of MetAP and evaluated for their potential activity in a wide range of diseases. MetAP inhibitors such as fumagillin, TNP-470, beloranib, and reversible inhibitors and their analogs guide new prospects for MetAP inhibitor development in the ongoing quest for new pharmacological indications. This perspective provides insights into recent advances related to MetAP, as a potential therapeutic target in drug discovery, bioactive small molecule MetAP2 inhibitors, and data on the role of MetAP-2 as a therapeutic target for microsporidiosis.

Fungi-Derived Bioactive Compounds as Potential Therapeutic Agents for Pancreatic Cancer: A Systematic Review

Pancreatic cancer (PC) is one of the tumors with the lowest 5-year survival rate worldwide due to late diagnosis and lack of effective therapy. Because of this, it is necessary to discover new ways of treatment to increase the quality of life of patients. In this context, the secondary metabolites of several fungi have been shown as a possible therapeutic strategy in several types of cancer, such as colorectal cancer, being able to trigger their action through the induction of apoptosis. The objective was to perform a systematic review process to analyze the studies carried out during the last ten years using secondary metabolites derived from fungi as antitumor treatment against PC. After the search process in three databases (PubMed, SCOPUS, and Web of Science) a total of 199 articles were found, with 27 articles finally being included after screening. The results extracted from this systematic review process made it possible to determine the existence of bioactive compounds extracted from fungi that have been effective in in vitro and in vivo conditions and that may be applicable as a possible therapy to avoid drug resistance in PC, one of the major problems of this disease.

Oxaliplatin-induced peripheral neurotoxicity in colorectal cancer patients: mechanisms, pharmacokinetics and strategies

Oxaliplatin-based chemotherapy is a standard treatment approach for colorectal cancer (CRC). However, oxaliplatin-induced peripheral neurotoxicity (OIPN) is a severe dose-limiting clinical problem that might lead to treatment interruption. This neuropathy may be reversible after treatment discontinuation. Its complicated mechanisms are related to DNA damage, dysfunction of voltage-gated ion channels, neuroinflammation, transporters, oxidative stress, and mitochondrial dysfunction, etc. Several strategies have been proposed to diminish OIPN without compromising the efficacy of adjuvant therapy, namely, combination with chemoprotectants (such as glutathione, Ca/Mg, ibudilast, duloxetine, etc.), chronomodulated infusion, dose reduction, reintroduction of oxaliplatin and topical administration [hepatic arterial infusion chemotherapy (HAIC), pressurized intraperitoneal aerosol chemotherapy (PIPAC), and hyperthermic intraperitoneal chemotherapy (HIPEC)]. This article provides recent updates related to the potential mechanisms, therapeutic strategies in treatment of OIPN, and pharmacokinetics of several methods of oxaliplatin administration in clinical trials.

The Chemotherapeutic Potentials of Compounds Isolated from the Plant, Marine, Fungus, and Microorganism: Their Mechanism of Action and Prospects

Research on natural products mainly focuses on developing a suitable drug to treat human disease. There has been a sharp increase in the development of drugs from natural products. Most of the drugs that are available are from the terrestrial origin. Marine natural products are less explored. Oceans are considered as a vast ecosystem with a wide variety of living organisms and natural products that are unexplored. Large numbers of antitumor drugs are from natural sources such as plants, marine, and microorganisms. 80% new chemical entities that were launched over the past 60 decades were from a natural source. In this article, the anticancer potential from the natural source such as plants, fungi, microorganisms, marine, and endophytes has been reviewed. Emphasis is given on the compound from the marine, plant, and of bacterial origin. Finally, we consider the future and how we might achieve better sustainability to alleviate human cancer suffering while having fewer side effects, more efficacies, and causing less harm than the present treatments.

Newly synthesized methionine aminopeptidase 2 inhibitor hinders tumor growth

Methionine aminopeptidase 2 (MetAp2) inhibition has been recognized as a promising approach for suppressing angiogenesis and cancer progression. Small molecule fumagillol derivatives with adamantane side groups were synthesized and evaluated for MetAp2 inhibition activity, and a lead molecule with superior abilities to inhibit the enzymatic activity of MetAp2 was identified. The compound, referred to as AD-3281, effectively suppressed proliferation of cancer and endothelial cells and impaired tube formation of endothelial cells in vitro. When administered systemically, AD-3281 was well tolerated and led to a significant suppression of human melanoma and mammary tumor xenografts grown in mice. The activity in vivo was associated with reduced angiogenesis and tumor proliferation as detected histologically. In order to develop a formulation that can solubilize AD-3281 with a minimal content of organic solvents, biodegradable nanoparticles comprised of poly-lactic-co-glycolic acid (PLGA) were fabricated and characterized. Compared with the free compound, AD-3281-loaded nanoparticles showed an advantageous cellular availability and uptake, leading to higher activity in cells and better transport in three-dimensional (3D) cultures. Taken together, we introduce a novel MetAp2 inhibitor with high anti-cancer activity and a stable nano-formulation with a high potential for future clinical translation.

Targeting methionine aminopeptidase 2 in cancer, obesity, and autoimmunity

For over three decades, methionine aminopeptidase 2 (MetAP2) has been a tentative drug target for the treatment of cancer, obesity, and autoimmune diseases. Currently, no MetAP2 inhibitors (MetAP2i) have reached the clinic yet, despite considerable investment by major pharmaceutical companies. Here, we summarize the key series of MetAP2i developed to date and discuss their clinical development, progress, and issues. We coalesce the currently disparate knowledge regarding MetAP2i mechanism of action and discuss discrepancies across varied studies. Finally, we highlight the current knowledge gaps that need to be addressed to enable successful development of MetAP2 inhibitors in clinical settings.

Integrating Molecular Networking and 1H NMR To Target the Isolation of Chrysogeamides from a Library of Marine-Derived Penicillium Fungi

A challenging problem in natural product discovery is to rapidly dereplicate known compounds and expose novel ones from complicated components. Herein, integrating the LC-MS/MS-dependent molecular networking and ¹H NMR techniques efficiently and successfully enabled the targeted identification of seven new cyclohexadepsipeptides, chrysogeamides A-G (1-7), from the coral-derived fungus Penicillium chrysogenum (CHNSCLM-0003) which was targeted from a library of marine-derived Penicillium fungi. Compound 4 features a rare 3-hydroxy-4-methylhexanoic acid (HMHA) moiety which was first discovered from marine-derived organisms. Interestingly, isotope-labeling feeding experiments confirmed that ¹³C₁-l-Leu was transformed into ¹³C₁-d-Leu moiety, indicating that d-Leu could be isomerized from l-Leu. Compounds 1 and 2 obviously promoted angiogenesis in zebrafish at 1.0 μg/mL with nontoxic to embryonic zebrafish at 100 μg/mL. Combining molecular networking with ¹H NMR as a discovery tool will be implemented as a systematic strategy, not only for known compounds dereplication but also for untapped reservoir discovery.

Therapeutic targets for the treatment of microsporidiosis in humans

INTRODUCTION

Microsporidia have been increasingly reported to infect humans. The most common presentation of microsporidiosis is chronic diarrhea, a significant mortality risk in immune-compromised patients. Albendazole, which inhibits tubulin, and fumagillin, which inhibits methionine aminopeptidase type 2 (MetAP2), are the two main therapeutic agents used for treatment of microsporidiosis. In addition, to their role as emerging pathogens in humans, microsporidia are important pathogens in insects, aquaculture, and veterinary medicine. New therapeutic targets and therapies have become a recent focus of attention for medicine, veterinary, and agricultural use. Areas covered: Herein, we discuss the detection and symptoms of microsporidiosis in humans and the therapeutic targets that have been utilized for the design of new drugs for the treatment of this infection, including triosephosphate isomerase, tubulin, MetAP2, topoisomerase IV, chitin synthases, and polyamines. Expert opinion: Enterocytozoon bieneusi is the most common microsporidia in human infection. Fumagillin has a broader anti-microsporidian activity than albendazole and is active against both Ent. bieneusi and Encephaliozoonidae. Microsporidia lack methionine aminopeptidase type 1 and are, therefore, dependent on MetAP2, while mammalian cells have both enzymes. Thus, MetAP2 is an essential enzyme in microsporidia and new inhibitors of this pathway have significant promise as therapeutic agents.

The use of external fixators in the definitive stabilisation of the pelvis in polytrauma patients: Safety, efficacy and clinical outcomes

OBJECTIVES

To analyse the complications and outcomes (functional/radiographic) of Pelvic External Fixators applied as part of the definitive fixation in polytrauma patients.

DESIGN

A single center retrospective chart review.

SETTING

A level-1 trauma center.

PATIENTS AND METHODS

We reviewed all the polytrauma patients (ISS>16) between 2007 and 2012 that had a PEF applied more than 30days. Complications including infection, aseptic loosening, neurological injury, loss of reduction, non-union and mal-union were recorded. Pelvic asymmetry and Deformity Index (DI) were measured at the immediate postoperative radiographs and final follow-up. The functional outcome at final follow up was estimated using a scale previously reported by Chiou et al.

RESULTS

59 patients with mean age of 38.4 (16 - 81) years and mean ISS score 28 (16- 66) were included. The PEFs were applied for mean duration of 56 (30-104) days. The average follow-up was 403days. 22 injuries were type B and 37 type C (AO/OTA). The most common symptomatic complications were pin site infection in 11 (18.6%) and loosening in 5 (8.5%) cases. 44 (74.5%) patients had satisfactory functional outcome. The immediate post-operative and final asymmetry and DI were compared between the two pelvic injury groups (type B and C fractures). The difference in displacement progression was more for type C injuries (p=0.034) but no correlation to the functional outcome was evident.

CONCLUSION

PEF can be used as definitive alternative stabilization method in specific situations at polytrauma setting. Radiological displacement occurred in both type B and C injuries but the clinical outcome was not correlated to this displacement. Complications related to PEF do not affect the final clinical outcome.

LEVEL OF EVIDENCE

Therapeutic Level III.

Common therapeutic target for both cancer and obesity

Obesity and cancer are two interrelated conditions of high epidemiological need, with studies showing that obesity is responsible for nearly 25% of the relative contribution to cancer incidence. Given the connection between these conditions, a drug that can operate on both obesity and cancer is highly desirable. Such a drug is accomplishable through the development of potent anti-angiogenesis agents due to the shared underlying role of angiogenesis in the development of both diseases. Prior research has demonstrated a key role of type-2 methionine aminopeptidase (MetAP2) for angiogenesis, which has led to the development of numerous of novel inhibitors. Several irreversible MetAP2 inhibitors have entered clinical trials without great success. Though this lack of success could be attributed to off-target adverse effects, the underlying causes remain unclear. More promising reversible inhibitors have been recently developed with excellent pre-clinical results. However, due to insufficient knowledge of the biological functions of N-terminal protein processing, it is hard to predict whether these novel inhibitors would successfully pass clinical trials and thereby benefit cancer and obesity patients. Significantly more efforts are needed to advance our understanding of the regulation of methionine aminopeptidases and the processes by which they govern the function of proteins.

Aspergillus, angiogenesis, and obesity: the story behind beloranib

Fumagillin, an antimicrobial compound first isolated in 1949 from the fungus Aspergillus fumigatus, four decades later was unexpectedly found to inhibit angiogenesis. Interest in developing angiogenesis inhibitor drugs as possible treatments for cancer led to the synthesis of analogs of fumagillin. Preclinical studies of various analog drugs confirmed that they inhibited angiogenesis, but they also were associated with weight loss as an adverse effect. Because adipose tissue can grow and regress throughout adulthood, is highly vascularized, and has angiogenic properties, interest in investigating anti-angiogenic agents in animal models of obesity found that fumagillin analogs caused dose-dependent reversible weight reduction and adipose tissue loss. Beloranib, a fumagillin analog that is an angiogenesis inhibitor and associated with decreased adiposity in animals, has been studied in phase I clinical trials for cancer. It is currently being investigated for the treatment of obesity and related conditions. Three phase I and three phase II studies found significant degrees of weight loss and acceptable tolerability for beloranib compared to placebo, justifying further clinical development of the drug for obesity.

Toward a Cancer Drug of Fungal Origin

Although fungi produce highly structurally diverse metabolites, many of which have served as excellent sources of pharmaceuticals, no fungi-derived agent has been approved as a cancer drug so far. This is despite a tremendous amount of research being aimed at the identification of fungal metabolites with promising anticancer activities. This review discusses the results of clinical testing of fungal metabolites and their synthetic derivatives, with the goal to evaluate how far we are from an approved cancer drug of fungal origin. Also, because in vivo studies in animal models are predictive of the efficacy and toxicity of a given compound in a clinical situation, literature describing animal cancer testing of compounds of fungal origin is reviewed as well. Agents showing the potential to advance to clinical trials are also identified. Finally, the technological challenges involved in the exploitation of fungal biodiversity and procurement of sufficient quantities of clinical candidates are discussed, and potential solutions that could be pursued by researchers are highlighted.

Anticancer Agents from Diverse Natural Sources

This review attempts to portray the discovery and development of anticancer agents/drugs from diverse natural sources. Natural molecules from these natural sources including plants, microbes and marine organisms have been the basis of treatment of human diseases since the ancient times. Compounds derived from nature have been important sources of new drugs and also serve as templates for synthetic modification. Many successful anti-cancer drugs currently in use are naturally derived or their analogues and many more are under clinical trials. This review aims to highlight the invaluable role that natural products have played, and continue to play, in the discovery of anticancer agents.

Synthesis and antiproliferative activity of ligerin and new fumagillin analogs against osteosarcoma

Ligerin (1) is a natural chlorinated merosesquiterpenoid related to fumagillin (2) exhibiting a selective antiproliferative activity against osteosarcoma cell lines and an in vivo antitumor activity in a murine model. Semisynthesis of ligerin analogs was performed in order to study the effects of the C3-spiroepoxide substitution by a halogenated moiety together with the modulation of the C6 chain. Results showed that all derivatives exhibited an in vitro antiproliferative activity against osteosarcoma cell lines and that chlorohydrin compounds were equally or more active than their spiroepoxy analogs. Among semisynthetic analogs, the parent compound 1 was the best candidate for further studies since it exhibited higher or equivalent activity compared to TNP470 (3) against SaOS2 and MG63 human osteosarcoma cells with a four times weaker toxicity against HFF2 human fibroblasts. Quantitative videomicroscopy analysis was conducted and allowed a better understanding of the mechanism of its antiproliferative activity.

Natural product and natural product derived drugs in clinical trials

The 25 Natural Product (NP)-derived drugs launched since 2008 and the 100 NP-derived compounds and 33 Antibody Drug Conjugates (ADCs) in clinical trials or in registration at the end of 2013 are reviewed.