New oral chemotherapeutic agents for lung cancer

Increasing the effectiveness of oxaliplatin using colloidal immunoglobulin G nanoparticles: Synthesis, cytotoxicity, interaction, and release studies

A novel biomacromolecule was prepared for a stabilizer sustained anticancer drug release system. Colloidal immunoglobulin G (IgG) nanoparticles (IgGNP) were synthesized and then characterized using FT-IR, SEM, zeta sizer, and AFM. Moreover, the formation of spherical shape IgGNP with an appropriate average size (144.56 ± 2 nm) and a narrow distribution for the drug release was confirmed. Also, the conjugation of oxaliplatin (OX) to IgGNP (OX@IgGNP) was demonstrated via the combination of spectroscopy and physical analyses. In this regard, the interaction was spantaneous with static quenching mechanism. OX caused well dispersity with no agglomeration on IgGNP with an average size of 142.31 ± 4 nm. Furthermore, the encapsulation efficiency (%EE) and drug loading (%DL) percentages were determined. Accordingly, the release behavior indicated that OX was sustained from IgGNP more than IgG (approximately 150 h) and the highest release amount of OX (100 %) was obtained at acidic medium (pH 5.5). Notably, the kinetic model was zero order and release mechanism followed by diffusion and Fick's model at neutral medium and combination of diffusion and swelling controlled and non-Fickian model at acidic medium. In addition, the anticancer effect of OX@IgGNP was evaluated on the human breast cancer cell lines, MCF-7 using MTT assay and DAPI staining that showed a remarkable efficacy, while the cytotoxicity in human fibroblast cell lines, HFFF2 has decreased. In this study, gene expression was investigated using real time PCR, which verified IgGNP induced programmed cell death in MCF-7 breast cancer cell more effectively than free OX. Subsequently, a novel nano scale biological macromolecule can be introduced as a sustained and prolonged anticancer drug release.

Highly enantioselective intermolecular Stetter reaction of simple acrylates: synthesis of α-chiral γ-ketoesters

Simple Stetter: A novel N-heterocyclic carbene (NHC) was designed by combining an electron-rich 2,6-dimethoxy substituent and an underestimated yet promising chiral motif. With this NHC in hand, a highly enantioselective intermolecular Stetter reaction of simple acrylates was developed, yielding versatile α-chiral γ-ketoesters. This represents the first catalytic asymmetric route towards these valuable compounds (see scheme).

Current status and perspective of antiangiogenic therapy for cancer: hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is well known as a typical angiogenic tumor, especially in the moderately to poorly differentiated type. Such clinicopathological characteristics are not only useful for imaging diagnosis but are also applicable to the treatment of HCC. In addition, recent molecular studies have revealed that angiogenesis is closely related to hepatocarcinogenesis. In this review, the molecular mechanism of HCC angiogenesis and the antiangiogenic prevention of HCC are reviewed to introduce the latest trends in antiangiogenic treatment of cancers, including HCC.

Anti-angiogenesis and angioprevention: mechanisms, problems and perspectives

The recognition that angiogenesis is a key early event in tumor progression and metastasis has led to the development of new strategies for cancer therapy. The generation of a new blood vessel network under physiological conditions is regulated by the concerted action of activators and inhibitors. Perturbation of this balance, as it occurs in solid tumor growth and metastasis, appears to be a critical point in tumorigenesis. This has led to the "angiogenic switch" hypothesis: the point at which a tumor acquires the potential to induce angiogenesis is a critical step towards malignancy. Based on experimental evidence, prevention of blood vessel development appears to be the mechanism of action of many successful chemopreventive drugs of natural or synthetic origin: a novel concept that we termed "angioprevention". The hypothesis that anti-angiogenesis is at the basis of tumor prevention also suggests that many anti-angiogenic drugs could be used for chemoprevention in higher risk populations or in early intervention. There is a growing body of experimental evidence that anti-angiogenic strategies will contribute to the future therapy of cancer, several compounds with anti-angiogenic properties are now under clinical investigation including anti-inflammatory compounds, as inflammation may play a key role in angiogenesis. We must persevere in the development of novel, powerful and safer angiogenesis inhibitors and in the use of anti-angiogenic drugs in combination with other natural or synthetic anti-cancer agents in a biological therapy strategy.

beta-Lapachone reduces endotoxin-induced macrophage activation and lung edema and mortality

beta-Lapachone, a 1,2-naphthoquinone, is a novel chemotherapeutic agent. It has been shown to be capable of suppressing inducible nitric oxide synthase expression and function in rat alveolar macrophages. The authors further performed experiments to examine the molecular mechanism of beta-lapachone on LPS-induced responses in rat alveolar macrophages and to evaluate its in vivo antiinflammatory effect. A significant increase in nitrite production and inducible nitric oxide synthase expression was elicited in macrophages treated with LPS that was inhibited by coincubation with beta-lapachone. beta-Lapachone could also inhibit the production of tumor necrosis factor-alpha induced by LPS. LPS induces protein tyrosine phosphorylation and nuclear factor-kappaB binding activity by gel mobility shift assay in macrophages. These events were significantly inhibited by beta-lapachone. Furthermore, beta-lapachone in vivo protected against the induction of lung edema, lung-inducible nitric oxide synthase protein expression and nuclear factor-kappaB activation, lethality, and increased plasma nitrite and serum tumor necrosis factor-alpha levels induced by LPS. These results indicate that beta-lapachone suppresses inducible nitric oxide synthase induction and tumor necrosis factor-alpha production mediated by the inhibition of protein tyrosine phosphorylation and nuclear factor-kappaB activation caused by LPS. This results in a beneficial effect in an animal model of sepsis.

Angioprevention': angiogenesis is a common and key target for cancer chemopreventive agents

The potential to block tumor growth by inhibition of the neoangiogenic process represents an intriguing approach to the treatment of solid tumors. The high proliferation rate in the tumor deprived of proper vascularization would be balanced by cell death due to lack of diffusion of nutrients and oxygen. Matrix metalloproteinases (MMPs), angiogenic growth factors, and their receptors are the main targets of an increasing number of clinical trials approved to test the tolerance and therapeutic efficacy of antiangiogenic agents. We observed that a series of substances proposed as possible cancer chemopreventive agents show antiangiogenic properties when tested in in vitro and in vivo angiogenesis models. We demonstrated that N-acetyl-l-cysteine is able to reduce the invasive and metastatic potential of melanoma cells, and to inhibit endothelial cell invasion by direct inhibition of MMP activity. We also showed that epigallocatechin gallate (EGCG), a flavonoid from green tea that possesses chemopreventive activity in experimental and epidemiological studies, is a potent inhibitor of MMP-2 and MMP-9. Angiogenesis has also been demonstrated to be a target for nonsteroidal anti-inflammatory drug chemopreventive activity. Based on these data, we hypothesize that other chemopreventive agents, including natural or synthetic retinoids, steroid hormone antagonists, peroxisome proliferator-activated receptor gamma ligands, vitamin D, and protease inhibitors, might have antiangiogenesis as an important mechanism of action, a novel concept we will term 'angioprevention'. We analyze the mechanisms on how and why chemopreventive agents could exert antiangiogenic effects aimed at controlling tumor growth, and their potential use in the clinic.

Synthesis of novel retinoid X receptor-selective retinoids

Retinoids 1-5 have been identified as potent RXR agonists for evaluation in the treatment of non-insulin-dependent (type II) diabetes mellitus (NIDDM). Highly convergent syntheses of 1-5 have been developed. The core tetrahydronaphthalene 7, employed in the synthesis of 1 and 2, was prepared in 98% yield using an AlCl(3)-catalyzed (0.03 equiv) Friedel-Crafts alkylation of toluene with 2,5-dichloro-2,5-dimethylhexane 6. A nitromethane-mediated Fridel-Crafts acylation of 7 with chloromethylnicotinate 9 was developed to prepare ketone 10 in 68% yield. Chelate-controlled addition of MeMgCl to 10 followed by dehydration afforded olefin 11 in 65% yield. Cyclopropanation of 11 with trimethylsulfoxonium ylide, followed by saponification, completed a five-step synthesis of 1 in 33% yield. FeCl(3)-catalyzed (0.05 equiv) Friedel-Crafts acylation of 7 with chloromethylterephthalate 14 afforded ketone 15 in 81% yield. Saponification of 15 and reaction with 50% aqueous NH(2)OH in AcOH afforded a 9:1 mixture of cis and trans oximes, from which the desired cis-oxime 2 was isolated in 43% yield. The core bromo-dihydronaphthalene 29 required for the synthesis of 3-5 was prepared by a Shapiro reaction. Transmetalation of 29 and reaction with Weinreb amides 30b or 36 afforded ketones 32 and 37, which were converted into 3-5 using chemistry comparable to the tetrahydronaphthylene series. Suzuki coupling of boronic acids 41 and 42 with vinyl triflate 43 provided an alternative approach to the synthesis of this class of compounds.