The treatment of ovarian cancer has traditionally been intractable, and required novel approaches to improve therapeutic efficiency. This paper reports that thio-glucose bound gold nanoparticles (Glu-GNPs) can be used as a sensitizer to enhance ovarian cancer radiotherapy. The human ovarian cancer cells, SK-OV-3, were treated by gold nanoparticles (GNPs) alone, irradiation alone, or GNPs in addition to irradiation. Cell uptake was assayed using inductively coupled plasma atomic emission spectroscopy (ICP-AES), while cytotoxicity induced by radiotherapy was measured using both 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di-phenytetrazoliumromide and clonogenic assays. The presence of reactive oxygen species (ROS) was determined using CM-H2-DCFDA confocal microscopy and cell apoptosis was determined by an Annexin V-FITC/propidium iodide (PI) kit with flow cytometry. The cells treated by Glu-GNPs resulted in an approximate 31% increase in nanoparticle uptake compared to naked GNPs (p < 0.005). Compared to the irradiation alone treatment, the intracellular uptake of Glu-GNPs resulted in increased inhibition of cell proliferation by 30.48% for 90 kVp and 26.88% for 6 MV irradiation. The interaction of x-ray radiation with GNPs induced elevated levels of ROS production, which is one of the mechanisms by which GNPs can enhance radiotherapy on ovarian cancer.

Allyl isothiocyanate (AITC) occurs in many commonly consumed cruciferous vegetables and exhibits significant anti-cancer activities. Available data suggest that it is particularly promising for bladder cancer prevention and/or treatment. Here, we show that AITC arrests human bladder cancer cells in mitosis and also induces apoptosis. Mitotic arrest by AITC was associated with increased ubiquitination and degradation of ␣-and ␤-tubulin. AITC directly binds to multiple cysteine residues of the tubulins. AITC induced mitochondrion-mediated apoptosis, as shown by cytochrome c release from mitochondria to cytoplasm, activation of caspase-9 and caspase-3, and formation of TUNEL-positive cells. Inhibition of caspase-9 blocked AITCinduced apoptosis. Moreover, we found that apoptosis induction by AITC depended entirely on mitotic arrest and was mediated via Bcl-2 phosphorylation at Ser-70. Pre-arresting cells in G 1 phase by hydroxyurea abrogated both AITC-induced mitotic arrest and Bcl-2 phosphorylation. Overexpression of a Bcl-2 mutant prevented AITC from inducing apoptosis. We further showed that AITC-induced Bcl-2 phosphorylation was caused by c-Jun N-terminal kinase (JNK), and AITC activates JNK. Taken together, this study has revealed a novel anticancer mechanism of a phytochemical that is commonly present in human diet.Allyl isothiocyanate (AITC) 2 is a naturally occurring compound that possesses both antimicrobial and anticancer activities. Many commonly consumed cruciferous vegetables are rich sources of AITC, such as mustard, horseradish, wasabi, and cabbage. Its bactericidal and fungicidal activities were demonstrated against a variety of pathogens, and its anticancer activities were shown in both cultured cancer cell lines and animal tumor models (1). Bioavailability of AITC is extremely high; nearly 90% of orally administered AITC is absorbed (1). Although available evidence indicates that the anticancer activity of AITC is neither cell-nor tissue-specific, we have recently shown that AITC is selectively delivered to bladder tissue through urinary excretion and potently inhibits cancer development and muscle invasion in an orthotopic rat bladder cancer model (2). Moreover, an AITC-rich mustard seed powder also strongly inhibited bladder cancer development and muscle invasion in vivo (3). Thus, AITC is highly promising for bladder cancer prevention and/or treatment. These results are also consistent with epidemiological studies showing an inverse association between consumption of cruciferous vegetables and bladder cancer risk (4, 5). In light of these findings, this study focuses on human bladder cancer cells.Previous studies have shown that AITC causes cell cycle arrest and apoptosis in cancer cell lines of different tissue origins in vitro and in several tumor xenograft models in vivo, and it modulates many genes and proteins involved in cancer cell survival and proliferation (1). In our recent studies, both AITC and the AITC-rich mustard seed powder mentioned above arrested bladder cancer cells in G 2 /M ...

Bladder cancer is one of the common human cancers and also has a very high recurrence rate. There is a great need for agents capable of inhibiting bladder cancer development and recurrence. Here, we report that allyl isothiocyanate (AITC), an ingredient of many common cruciferous vegetables, potently inhibited the proliferation of bladder carcinoma cell lines in vitro [half maximal inhibitory concentration (IC(50)) of 2.7-3.3 microM], which was associated with profound G(2)/M arrest and apoptosis. In contrast, AITC was markedly less toxic to normal human bladder epithelial cells (IC(50) of 69.4 microM). AITC was then evaluated in two rat bladder cancer models in vivo (an orthotopic model and a subcutaneous model). The orthotopic model closely mimics human bladder cancer development and recurrence. We show that a low oral dose of AITC (1 mg/kg) significantly inhibited the development and muscle invasion of the orthotopic bladder cancers but was ineffective against the subcutaneous xenografts of the same cancer cells in the same animals. This differential effect was explained by our finding that urinary levels of AITC equivalent were two to three orders of magnitude higher than that in the plasma and that its levels in the orthotopic cancer tissues were also three orders of magnitude higher than that in the subcutaneous cancer tissues. Moreover, we show that AITC is a multi-targeted agent against bladder cancer. In conclusion, AITC is selectively delivered to bladder cancer tissue through urinary excretion and potently inhibits bladder cancer development and invasion.

Protein engineering to expand the substrate spectrum of native enzymes opens new possibilities for bioproduction of valuable chemicals from non-natural pathways. No natural microorganism can directly use sugars to produce 1,3-propanediol (PDO). Here, we present a de novo route for the biosynthesis of PDO from sugar, which may overcome the mentioned limitations by expanding the homoserine synthesis pathway. The accomplishment of pathway from homoserine to PDO is achieved by protein engineering of glutamate dehydrogenase (GDH) and pyruvate decarboxylase to sequentially convert homoserine to 4-hydroxy-2-ketobutyrate and 3-hydroxypropionaldehyde. The latter is finally converted to PDO by using a native alcohol dehydrogenase. In this work, we report on experimental accomplishment of this non-natural pathway, especially by protein engineering of GDH for the key step of converting homoserine to 4-hydroxy-2-ketobutyrate. These results show the feasibility and significance of protein engineering for de novo pathway design and overproduction of desired industrial products.

Pharmacokinetics and bio-distribution are crucial factors affecting the performance of an intravenous drug. In this study, we explore the combined use of glucose and polyethylene glycol (PEG) ligands to further improve gold nanoparticle (GNP) pharmacokinetics and bio-distribution, with the aim of using the drug for in-vivo radiotherapy. The inclusion of PEG was found to significantly prolong the half-life period, where PEG-Glu-GNPs achieved 6.17 +/- 3.71 h, compared to 1.23 +/- 0.14 h for Glu-GNPs and 1.07 +/- 0.22 h for uncoated GNPs. Our data indicates that nanoparticle size impacts cell uptake performance, with 20 nm being the optimal diameter for cancer treatment applications. Although PEG-Glu-GNPs mainly distributed in the spleen, liver, lung, and kidneys, the concentration of PEG-Glu-GNPs in tumour tissue was 20 times higher than healthy cells in the uterus and ovaries, reaching 9.22 +/- 2.41 microg/g cancer tissue at 48 h after injection. This difference in uptake holds promise for selective tumor targeting which can in turn lead to more effective radiotherapy through the interaction of X-rays and GNPs. Specifically tumor size after 47 days of treatment had reduced to (769 +/- 92) mm3 compared to (1432 +/- 269) mm3 using X-rays alone and (3514 +/- 1818) mm3 without any treatment. Moreover, the mice remained healthy without statistically significant weight loss. Results of our pharmacokinetic and bio-distribution study as well as therapeutic data for PEG-Glu-GNPs in our tumor bearing animal model demonstrate that PEG-Glu-GNPs provide excellent in-vivo stability, tumor targeting function, and radiotherapeutic enhancement effects, providing useful insights for further clinical studies.