NK cells adjuvant therapy shows survival benefits in a gastric mixed signet ring cell carcinoma patient: A case report.

RATIONALE: Advanced signet ring cell (SRC) carcinoma has a worse prognosis. Therefore, early diagnosis and prevention is particularly important; SRC tumors have lower R0 resection rate and are thought to be less chemosensitive than non-SRCC. Consequently, a novel postoperative adjuvant treatment is urgently needed to improve clinical outcomes. PATIENT CONCERNS: A 41-year-old female with advanced gastric SRC carcinoma was treated with radical gastrectomy and oxaliplatin-based regimen for 6 cycles after surgery. She was suspected of recurrence with the high level of carbohydrate antigen (CA) 72-4. DIAGNOSES: The gastroscopy revealed SRC carcinoma of gastric antrum and poorly differentiated adenocarcinoma in some areas. The diagnosis of postoperative pathology report was gastric cancer with stage III C (T4a, N3a, M0). INTERVENTIONS: The level of CA72-4 rapidly increased during the 2 follow-up after the completion of conventional treatment, ex vivo-cultured allogeneic natural killer (NK) cell infusion was offered to prevent recurrence. OUTCOMES: Intravenous injections of NK cells combination with surgical treatment and chemotherapy showed therapeutic effects in this patient with possible relapse. The patient remained disease-free 46 months after the infusion of NK cells until the latest follow-up. LESSONS: CA72-4 appeared to be the most sensitive and specific marker in the gastric cancer patient, and the high level of CA72-4 may indicate the risk of recurrence. This case report provide rationale for NK cell infusion following the rapid increase of CA72-4 to prevent recurrence.

LXYL-P1-2 immobilized on magnetic nanoparticles and its potential application in paclitaxel production

BACKGROUND: LXYL-P1-2 is the first reported glycoside hydrolase that can catalyze the transformation of 7-b-xylosyl-10-deacetyltaxol (XDT) to 10-deacetyltaxol (DT) by removing the D-xylosyl group at the C7 position. Successful synthesis of paclitaxel by one-pot method combining the LXYL-P1-2 and 10- deacetylbaccatin III-10-b-O-acetyltransferase (DBAT) using XDT as a precursor, making LXYL-P1-2 a highly promising enzyme for the industrial production of paclitaxel. The aim of this study was to investigate the catalytic potential of LXYL-P1-2 stabilized on magnetic nanoparticles, the surface of which was modified by Ni2+-immobilized cross-linked Fe3O4@Histidine. RESULTS: The diameter of matrix was 20­40 nm. The Km value of the immobilized LXYL-P1-2 catalyzing XDT (0.145 mM) was lower than that of the free enzyme (0.452 mM), and the kcat/Km value of immobilized enzyme (12.952 mM s 1 ) was higher than the free form (8.622 mM s 1 ). The immobilized form maintained 50% of its original activity after 15 cycles of reuse. In addition, the stability of immobilized LXYL-P1-2, maintained 84.67% of its initial activity, improved in comparison with free form after 30 d storage at 4 C. CONCLUSIONS: This investigation not only provides an effective procedure for biocatalytic production of DT, but also gives an insight into the application of magnetic material immobilization technology.

Chemoradiotherapy combined with NK cell transfer in a patient with recurrent and metastatic nasopharyngeal carcinoma inducing long-term tumor control: A case report.

RATIONALE: Nasopharyngeal carcinoma (NPC) is one of the most common malignancies in Southern China. Although combined chemotherapy with radiotherapy has been widely used in treating locally advanced lesions, relapse and metastases remain the primary cause of treatment failure, and are associated with an extremely poor prognosis. Therefore, more efficient and milder therapies are needed. PATIENT CONCERNS: Herein, we report a patient with advanced NPC with intracranial metastases who showed progression during conventional treatment. DIAGNOSES: Nonkeratinizing undifferentiated nasopharyngeal carcinoma (stage IV). INTERVENTIONS: After the completion of initial chemoradiotherapy and targeted therapy, metastases to brain occurred during follow-up. Ex vivo-cultured allogeneic NK cell infusion was offered. OUTCOMES: Although the intracranial metastases did not decrease 10 months after the NK cell treatment, they decreased significantly at 31 months after the treatment and partially disappeared. The tumor response indicated partial response. Furthermore, all of the intracranial metastases continued to decrease at about 42 months after treatment. LESSONS: The brain metastases of NPC are rare with poor prognosis. Radiotherapy in NPC can disrupt the blood-brain barrier, which may contribute to the metastases of brain. This case report will provide rationale for NK cell infusion following regular chemoradiotherapy.

Design, synthesis and structure-activity relationships of novel 15-membered macrolides: Quinolone/quinoline-containing sidechains tethered to the C-6 position of azithromycin acylides.

In the search for novel hybrid molecules by fusing two biologically active scaffolds into one heteromeric chemotype, we found that hybrids of azithromycin and ciprofloxacin/gatifloxacin 26j and 26l can inhibit the supercoiling activity of E. coli gyrase by poisoning it in a way similar to fluoroquinolones. This may modestly contribute to their potencies, which are equal to ciprofloxacin against constitutively resistant Staphylococcus aureus, whose growth is not inhibited by the presence of macrolides. In contrast, introduction of quinolines (the 3-quinoline 26b and the 6-quinoline 26o) with an optimized rigid spacer at the 6-OH of azithromycin acylides did not exert significant potency against constitutively resistant S. aureus, despite the fact that the quinoline-containing compounds, exemplified by 26o, were as active as telithromycin against susceptible, inducibly- and efflux-resistant pathogens. The novel dual modes of action involving protein synthesis inhibition and poisoning DNA replication may pave the way for restoration of antibacterial activities of the current macrolides against constitutively resistant clinical isolates.

[Advances in the research of inhibitors of enzymes of bacterial peptidoglycan biosynthesis].

In recent years, owing to the abuse of antibiotics, the widespread of resistant bacterial strains became a serious threat to public health. This status demands development of new antibacterial agents with novel mechanisms of action. The reason for the limited new antibacterials is the small number of effective therapeutic targets, which cannot meet the current needs for the multiple drug-resistant treatment. Screening for new targets is the key step in the development of novel antibacterial agents. Peptidoglycan is the main component of the cell wall of bacteria, which is essential for survival of pathogenic bacteria. Within the biochemical pathway for peptidoglycan biosynthes is the Murligases, described in this review as highly potential targets for the development of new classes of antibacterial agents. This review provides an in-depth insight into the recent developments in the field of inhibitors of the Mur enzymes (MurA-F). Moreover, the reasons for the lack of candidate inhibitors and the challenges to overcome the hurdles are also discussed.

The whole-cell immobilization of D-hydantoinase-engineered Escherichia coli for D-CpHPG biosynthesis

Background: D-Hydroxyphenylglycine is considered to be an important chiral molecular building-block of antibiotic reagents such as pesticides, and β-lactam antibiotics. The process of its production is catalyzed by D-hydantoinase and D-carbamoylase in a two-step enzyme reaction. How to enhance the catalytic potential of the two enzymes is valuable for industrial application. In this investigation, an Escherichia coli strain genetically engineered with D-hydantoinase was immobilized by calcium alginate with certain adjuncts to evaluate the optimal condition for the biosynthesis of D-carbamoyl-p-hydroxyphenylglycine (D-CpHPG), the compound further be converted to D-hydroxyphenylglycine (D-HPG) by carbamoylase. Results: The optimal medium to produce D-CpHPG by whole-cell immobilization was a modified Luria-Bertani (LB) added with 3.0% (W/V) alginate, 1.5% (W/V) diatomite, 0.05% (W/V) CaCl2 and 1.00 mM MnCl2.The optimized diameter of immobilized beads for the whole-cell biosynthesis here was 2.60 mm. The maximized production rates of D-CpHPG were up to 76%, and the immobilized beads could be reused for 12 batches. Conclusions: This investigation not only provides an effective procedure for biological production of D-CpHPG, but gives an insight into the whole-cell immobilization technology.

New C-19-modified geldanamycin derivatives: synthesis, antitumor activities, and physical properties study.

Thiazinogeldanamycin (2) was identified from Streptomyces hygroscopicus 17997 at the late stage of the fermentation. The pH was firstly proposed as an important factor in the biosynthesis of it. It was verified that 2 was produced by direct chemical reactions between geldanamycin (1, GDM) and cysteine or aminoethanethiol hydrochloride at pH > 7 in vitro. The proposed synthesis pathway for compound 2 was also discussed. Eleven new C-19-modified GDM derivatives, including five stable hydroquinone form derivatives, were synthesized, most of which exhibited desirable properties such as lower cytotoxicity, increased water solubility, and potent antitumor activity. Especially, compounds 5 and 8 showed antitumor activities against HepG2 cell with IC50 values of 2.97-6.61 µM, lower cytotoxicity and at least 15-fold higher water solubility compared with 1 in pH 7.0 phosphate buffer.

[Identification of tetracenomycin X from a marine-derived Saccharothrix sp. guided by genes sequence analysis].

The crude extracts of the fermentation broth from a marine sediment-derived actinomycete strain, Saccharothrix sp. 10-10, showed significant antibacterial activities against drug-resistant pathogens. A genome-mining PCR-based experiment targeting the genes encoding key enzymes involved in the biosynthesis of secondary metabolites indicated that the strain 10-10 showed the potential to produce tetracenomycin-like compounds. Further chemical investigation of the cultures of this strain led to the identification of two antibiotics, including a tetracenomycin (Tcm) analogs, Tcm X (1), and a tomaymycin derivative, oxotomaymycin (2). Their structures were identified by spectroscopic data analysis, including UV, 1D-NMR, 2D-NMR and MS spectra. Tcm X (1) showed moderate antibacterial activities against a number of drug-resistant pathogens, including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococci (VRE) pathogens, with the MIC values in the range of 32-64 microg x mL(-1). In addition, 1 also displayed significant cytotoxic activities against human cancer cell lines, including HL60 (leukemia), HepG2 (liver), and MCF-7 (breast) with the IC 50 values of 5.1, 9.7 and 18.0 micromol x L(-1), respectively. Guided by the PCR-based gene sequence analysis, Tcm X (1) and oxotomaymycin (2) were identified from the genus of Saccharothrix and their 13C NMR data were correctly assigned on the basis of 2D NMR spectroscopic data analysis for the first time.

[Halogenated natural products from the marine-derived actinobacteria and their halogenation mechanism].

In the last decade, along with the development of taxonomy research in marine-derived actinobacteria, more and more halogenated natural products were discovered from marine actinobacteria. Most of them showed good biological activity and unique structure compared to those from land. The special halogenation mechanism in some compounds' biosynthesis has drawn great attention. So in this review, we focus on the halogenated natural products from marine actinobacteria and their halogenation mechanisms.

[Glycosyl isomerization based on the biosynthesis of natural-product sugar from microorganism].

Glycosylation, one of the most common and important reactions in biological systems, results in diverse functions and is often found in biologically active small-molecule natural products produced by microorganisms. Furthermore, sugar moieties are generally critical for their activities. Alternating the sugar structures thus provides the potentials for enhancing the biological activities of natural products, which evokes researchers to study the sugar biosynthetic machinery and its application in the modification of sugar moieties with an aim of generating unnaturally glycosylated natural product drugs with better activities. This review will briefly outline current studies on sugar biosynthesis and glycosyltransferase, with a few selected experiments designed to alter natural-product sugar structures.

Substituted benzothiophene or benzofuran derivatives as a novel class of bone morphogenetic protein-2 up-regulators: synthesis, structure-activity relationships, and preventive bone loss efficacies in senescence accelerated mice (SAMP6) and ovariectomized rats.

In this work, substituted benzothiophene and benzofuran compounds were found to be a new class of potential anabolic agents by enhancing BMP-2 expression. A series of benzothiophene and benzofuran derivatives have been synthesized, and their activities of up-regulating BMP-2 and bone loss prevention efficacies in SAMP6 mice and OVX rats have been studied. Benzothiophenes 1, 3, 14, 4a, 7a, 8a, and benzofuran analogue 2 showed higher BMP-2 up-regulation rates in vitro. Compound 8a was found to significantly affect the bone formation rate of tested SAMP6 mice. Compound 1 showed an improved bone quality in SAMP6 mice and also showed activity in OVX rats. We have demonstrated that substituted benzothiophene and benzofuran derivatives, especially compounds 1 and 8a, enhance BMP-2 expression in vitro and in vivo and stimulate bone formation and trabecular connectivity restoration in vivo. The compounds represent potential leads in the development of a new class of anabolic agents.

Synthesis and evaluation of 1-(benzo[b]thiophen-2-yl)ethanone analogues as novel anti-osteoporosis agents acting on BMP-2 promotor.

A novel series of 1-(benzo[b]thiophen-2-yl)ethanone analogues were prepared and evaluated for enhancing BMP-2 expression. Compounds 1-5, 7, 8, 12, 13 and 16, with upregulation rate values of 35.6%, 27.9%, 39.8%, 32.0%, 37.1%, 30.2%, 28.0%, 33.5%, 22.8% and 27.3% in vitro, respectively, at a concentration of 4muM, exhibited potent effect for enhancing BMP-2 expression. We also found that compounds 1 and 12 produced a dose-dependent increase on bone histology and histomorphometry, and effectively reduced bone defects induced by ovariectomy in an ovariectomized rat model (OVX).

Nocardia jinanensis sp. nov., an amicoumacin B-producing actinomycete.

A novel actinomycete, strain 04-5195(T), that produces amicoumacin B, which targets bone morphogenetic protein-2, was isolated from a soil sample collected in Jinan, Shandong Province, China. Strain 04-5195(T) had morphological, biochemical, physiological and chemotaxonomic properties that were consistent with its classification in the genus Nocardia and it formed a phyletic line in the Nocardia 16S rRNA gene tree. It was evident from the phylogenetic data that strain 04-5195(T) was most closely associated with Nocardia speluncae N2-11(T). However, the two organisms were distinguishable from one another using DNA-DNA relatedness and phenotypic data. The isolate was readily differentiated from other related Nocardia strains by a set of phenotypic properties and by its phylogenetic position. Therefore, it is proposed that the isolate represents a novel species in the genus Nocardia, Nocardia jinanensis sp. nov.; the type strain is 04-5195(T) (=CGMCC 4.3508(T) =DSM 45048(T)).