Publications by authors named "Oksik Choi"

Purpose: This study aimed to toxicological evaluate a probiotics-based delivery system for p8 protein as an anti-colorectal cancer drug.

Introduction: Lactic acid bacteria (LAB) have been widely ingested for many years and are regarded as very safe. Recently, a SL4 (PP) strain that secretes the probiotic-derived anti-cancer protein P8 (PP-P8) has been developed as an anti-colorectal cancer (CRC) biologic by Cell Biotech.

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Background: Successful chemoprevention or chemotherapy is achieved through targeted delivery of prophylactic agents during initial phases of carcinogenesis or therapeutic agents to malignant tumors. Bacteria can be used as anticancer agents, but efforts to utilize attenuated pathogenic bacteria suffer from the risk of toxicity or infection. Lactic acid bacteria are safe to eat and often confer health benefits, making them ideal candidates for live vehicles engineered to deliver anticancer drugs.

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Despite decades of research into colorectal cancer (CRC), there is an ongoing need for treatments that are more effective and safer than those currently available. Lactic acid bacteria (LAB) show beneficial effects in the context of several diseases, including CRC, and are generally regarded as safe. Here, we isolated a (LR)-derived therapeutic protein, p8, which suppressed CRC proliferation.

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Background: Styrene and its derivatives as monomers and petroleum-based feedstocks are valuable as raw materials in industrial processes. The chemical reaction for styrene production uses harsh reaction conditions such as high temperatures or pressures, or requires base catalysis with microwave heating. On the other hand, production of styrene and its derivatives in Escherichia coli is an environmental friendly process to produce conventional petroleum-based feedstocks.

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Background: Methylated resveratrol analogs show similar biological activities that are comparable with those of the resveratrol. However, the methylated resveratrol analogs exhibit better bioavailability as they are more easily transported into the cell and more resistant to degradation. Although these compounds are widely used in human health care and in industrial materials, at present they are mainly obtained by extraction from raw plant sources.

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Resveratrol, which is a polyphenolic antioxidant, is dose-dependent when used to provide health benefits, to enhance stress resistance, and to extend lifespans. However, even though resveratrol has therapeutic benefits, its clinical therapeutic effect is limited owing to its low oral bioavailability. An Escherichia coli system was developed that contains an artificial biosynthetic pathway that produces resveratrol glucoside derivatives, such as resveratrol-3-Oglucoside (piceid) and resveratrol-4'-O-glucoside (resveratroloside), from simple carbon sources.

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Background: The phenylpropanoid metabolites are an extremely diverse group of natural products biosynthesized by plants, fungi, and bacteria. Although these compounds are widely used in human health care and nutrition services, their availability is limited by regional variations, and isolation of single compounds from plants is often difficult. Recent advances in synthetic biology and metabolic engineering have enabled artificial production of plant secondary metabolites in microorganisms.

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Biological synthesis of plant secondary metabolites has attracted increasing attention due to their proven or assumed beneficial properties and health-promoting effects. Phenylpropanoids are the precursors to a range of important plant metabolites such as the secondary metabolites belonging to the flavonoid/stilbenoid class of compounds. In this study, engineered Escherichia coli containing artificial phenylpropanoid biosynthetic pathways utilizing tyrosine as the initial precursor were established for production of plant-specific metabolites such as ferulic acid, naringenin, and resveratrol.

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The molecular chaperone heat shock protein 90 (Hsp90) is responsible for maintaining the correct folding and stability of many signaling proteins. It is a promising target of cancer therapeutics and several other diseases, including neurodegenerative disease, nerve injuries, inflammation, and infection. In an effort to identify new Hsp90 inhibitors from natural sources using an in vitro ATPase inhibition assay, two 6-alkylsalicylic acid analogues, salaceyin A and B were identified from the culture extract of Streptomyces.

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Tailor made: We report the rational biosynthesis of C15 hydroxylated non-quinone geldanamycin analogues by site-directed mutagenesis of the geldanamycin polyketide synthase (PKS), together with a combination of post-PKS tailoring genes. Rational biosynthetic engineering allowed the generation of geldanamycin derivatives, such as DHQ3 illustrated in the figure, which had superior pharmacological properties in comparison to the parent compound. A rational biosynthetic engineering approach was applied to the optimization of the pharmacological properties of the benzoquinone ansamycin, geldanamycin.

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