Chemoenzymatic Synthesis of Cylindrocyclophanes A and F and Merocyclophanes A and D.

Incorporating enzymatic reactions into natural product synthesis can significantly improve synthetic efficiency and selectivity. In contrast to the increasing applications of biocatalytic functional-group interconversions, the use of enzymatic C-C bond formation reactions in natural product synthesis is underexplored. Herein, we report a concise and efficient approach for the synthesis of [7.7]paracyclophane natural products, a family of polyketides with diverse biological activities. By using enzymatic Friedel-Crafts alkylation, cylindrocyclophanes A and F and merocyclophanes A and D were synthesized in six to eight steps in the longest linear sequence. This study demonstrates the power of combining enzymatic reactions with contemporary synthetic methodologies and provides opportunities for the structure-activity relationship studies of [7.7]paracyclophane natural products.

Silencing SIX1 by miR-7160 inhibits non-small cell lung cancer cell growth.

The homeoprotein SIX1 is upregulated in non-small cell lung cancer (NSCLC) and associated with NSCLC tumorigenesis and progression. We identified microRNA-7160 (miR-7160) as a SIX1-targeting miRNA. RNA immunoprecipitation results confirmed a direct binding between miR-7160 and SIX1 mRNA in NSCLC cells. In the primary and established NSCLC cells, forced overexpression of miR-7160 downregulated SIX1 and inhibited cancer cell growth, proliferation, migration and invasion. Furthermore, miR-7160 overexpression induced apoptosis activation in NSCLC cells. Conversely, miR-7160 inhibition elevated SIX1 expression and enhanced NSCLC cell progression in vitro. Restoring SIX1 expression, by an untranslated region-depleted SIX1 expression construct, reversed miR-7160-induced anti-NSCLC cell activity. CRISPR/Cas9-inudced knockout of SIX1 mimicked miR-7160-induced actions and produced anti-NSCLC cell activity. In vivo, intratumoral injection of miR-7160-expressing lentivirus downregulated SIX1 mRNA and inhibited NSCLC xenograft growth in severe combined immunodeficient mice. Significantly, miR-7160 expression is downregulated in human NSCLC tissues and is correlated with SIX1 mRNA upregulation. Collectively, miR-7160 silenced SIX1 and inhibited NSCLC cell growth in vitro and in vivo.

Syntheses of the Carotane-type Terpenoids (+)-Schisanwilsonene A and (+)-Tormesol via a Two-Stage Approach.

Stereoselective syntheses of terpenoids in a more efficient manner have been a long-term pursuit for synthetic chemists. Herein we describe the two-step, enantiospecific and protecting-group-free synthesis of (+)-schisanwilsonene A from a carotane compound, which was produced in E. coli. We also completed the first enantiomeric synthesis of (+)-tormesol in five steps. The two-stage strategy offers a step- and redox-economical approach to prepare terpene natural products and their analogues.

Syntheses of Epoxyguaiane Sesquiterpenes (-)-Englerin A, (-)-Oxyphyllol, (+)-Orientalol E, and (+)-Orientalol F: A Synthetic Biology Approach.

A combined approach toward syntheses of epoxyguaiane sesquiterpenes is presented. By use of a fungus sesquiterpene cyclase, guaian-6,10(14)-diene was produced through metabolic engineering of the isoprenoid pathway in E. coli. (-)-Englerin A, (-)-oxyphyllol, (+)-orientatol E, and (+)-orientalol F have been synthesized in two to six steps. This strategy provided rapid access to the epoxyguaiane core structure and would facilitate syntheses of (-)-englerin A and its analogues for evaluation of their therapeutic potentials in drug discovery.

Impact of COPD and emphysema on survival of patients with lung cancer: A meta-analysis of observational studies.

Both COPD and emphysema are associated with an increased incidence of lung cancer, but the impacts of these comorbidities on lung cancer prognosis are still unclear. Herein, we conducted a meta-analysis to clarify whether the presence of these comorbidities indicates poor survival in patients with lung cancer. A comprehensive search was conducted using PubMed, Embase, Web of Science, ASCO Abstracts and Cochrane library for articles published before 1 June 2015. Papers referenced by the obtained articles were also reviewed. Main outcomes were overall survival (OS) and disease-free survival (DFS) in patients with lung cancer. Pooled hazard ratio (HR) and 95% confidence intervals (CIs) were calculated using random-effects models. Subgroup and sensitivity analyses were also conducted. Of 58 full texts reviewed, 26 met our inclusion criteria that were derived from 21 and seven studies examining the impacts of COPD and emphysema on survival of lung cancer, respectively. Meta-analyses revealed that concomitant COPD was associated with poorer OS (HR, 1.17; 95% CI: 1.10-1.25, n = 20), which was independent of tumour staging, diagnostic criteria of COPD or location, and DFS (HR, 1.52; 95% CI: 1.04-2.23, n = 6) with high heterogeneity (I(2) = 78%). The presence of emphysema in patients with lung cancer predicted worse OS (HR, 1.66; 95% CI: 1.25-2.22, n = 7), but not poorer DFS. The presence of COPD and emphysema are robust predictors of poor survival in patients with lung cancer. Early detection of these diseases should be taken into account for lung cancer surveillance and management.

Ginsenoside Rg3 sensitizes human non-small cell lung cancer cells to γ-radiation by targeting the nuclear factor-κB pathway.

At present, it is elusive how non-small cell lung cancer (NSCLC) develops resistance to γ-radiation; however, the transcription factor nuclear factor-κB (NF-κB) and NF-κB-regulated gene products have been proposed as mediators. Ginsenoside Rg3 is a steroidal saponin, which was isolated from Panax ginseng. Ginsenoside Rg3 possesses high pharmacological activity and has previously been shown to suppress NF-κB activation in various types of tumor cell. Therefore, the present study aimed to determine whether Rg3 could suppress NF-κB activation in NSCLC cells and sensitize NSCLC to γ-radiation, using an NSCLC cell line and NSCLC xenograft. A clone formation assay and lung tumor xenograft experiment were used to assess the radiosensitizing effects of ginsenoside Rg3. NF-κB/inhibitor of NF-κB (IκB) modulation was ascertained using an electrophoretic mobility shift assay and western blot analysis. NF-κB-regulated gene products were monitored by western blot analysis. The present study demonstrated that ginsenoside Rg3 was able to sensitize A549 and H1299 lung carcinoma cells to γ-radiation and significantly enhance the efficacy of radiation therapy in C57BL/6 mice bearing a Lewis lung carcinoma cell xenograft tumor. Furthermore, ginsenoside Rg3 suppressed NF-κB activation, phosphorylation of IκB protein and expression of NF-κB-regulated gene products (cyclin D1, c-myc, B-cell lymphoma 2, cyclooxygenase-2, matrix metalloproteinase-9 and vascular endothelial growth factor), a number of which were induced by radiation therapy and mediate radioresistance. In conclusion, the results of the present study suggested that ginsenoside Rg3 may potentiate the antitumor effects of radiation therapy in NSCLC by suppressing NF-κB activity and NF-κB-regulated gene products, leading to the inhibition of tumor progression.

Serum miR-21 and miR-155 expression in idiopathic pulmonary fibrosis.

OBJECTIVE: To investigate the expression of serum miRNA-21(miR-21) and miRNA-155 (miR-155) in idiopathic pulmonary fibrosis (IPF). METHODS: A study including 65 patients with IPF and 65 similar age and gender healthy controls was performed. Serum specimens were collected from all subjects. Total RNA was extracted and the quantitative reverse transcription-polymerase chain reaction was used to measure serum miR-21 and miR-155 in both groups. Clinicopathologic features were assessed to determine associations with serum miR-21 and miR-155 concentrations. RESULTS: Serum miR-21 expression was significantly higher in IPF samples than in healthy controls (p < 0.01), while serum miR-155 expression did not show a statistically significant difference (p > 0.05). Forced vital capacity (FVC) and radiologic features were associated with miR-21 and miR-155 expression in serum (p < 0.05). Neither miR-21 nor miR-155 expression was statistically significantly associated with clinicopathologic parameters, such as gender (p > 0.05) and age (p > 0.05). CONCLUSION: These findings suggest that serum miR-21 is associated with IPF and the degree of damage indicated by FVC and radiologic examinations could correlate with miR-21 and miR-155 expression in serum. From another perspective, our study confirmed serum miRNA can be stable and detectable in serum of patients with IPF, which could prove useful as it could be considered as a new biomarker in serum for diagnosis and assessment of prognosis of IPF in the future.

Construction and characterization of a eukaryotic expression vector for small interfering RNA targeting the NEDD9 gene.

The aim of this study was to construct a eukaryotic expression vector for a small interfering RNA (siRNA) targeting the neural precursor cell expressed, developmentally downregulated 9 (NEDD9) gene, and to investigate the effects of RNA interference (RNAi) on NEDD9 expression in human lung adenocarcinoma A549 cells. We used the siRNA design and analysis software to determine the target oligonucleotides according to the sequence of NEDD9 mRNA available in GenBank. Four siRNA sequences were obtained, and the corresponding cDNAs were synthesized and inserted into the pRNAT-CMV3.2 plasmid to construct the recombinant plasmids. These were transformed into the E. coli strain DH5α. The plasmids, after identification by PCR and DNA sequencing, were transfected into the A549 cell line via the liposome method. NEDD9 mRNA and protein in the cells were determined by fluorescence quantitative RT-PCR (FQ-PCR) and western blotting, respectively. The pRNAT-CMV3.2-transfected plasmid was used as a control. Four recombinant plasmids were identified by PCR and sequence analysis, which contained the correct insertion of the designed sequences in the plasmids. FQ-PCR and western blotting showed substantially decreased mRNA and protein expression of the NEDD9 gene in the transfected cells, compared with the control group. In conclusion, the recombinant plasmids expressing the siRNA targeting the NEDD9 gene were successfully constructed, and the siRNA expression vectors inhibited the expression of NEDD9 in A549 cells.

[Identification and analysis of rice drought tolerance using near infrared diffuse reflection spectra of leaves].

In the present study, different drought tolerance rice from different countries and areas were selected and grown in water field and drought field respectively, including 4 traditional varieties of drought rice, 18 varieties of modified drought rice, 2 varieties of drought traits rice, 2 varieties of drought tolerance rice, and a total of 30 different varieties of drought tolerance rice were involved. Using near infrared diffuse reflection spectra of leaves from water field and drought field, we studied the rice drought tolerance identification analysis. Results showed that: using the average spectra of several leaves' spectra, selecting 4,500-7,500 cm(-1) as effective analysis spectra zone, choosing the first derivative and multiple scattering correction (MSC) as spectra preprocessing method, we can set up the calibration models between the spectra of leaves from drought field and the yield of rice. Simultaneously, we concluded that the performance of calibration model for rice yield and drought tolerance identification indexes in the upper booting stage was better than in the previous booting stage whose correlation coefficient of cross validation could reach 0.8. But there was no obvious relation between the spectra from water field and the yield, the drought tolerance identification indexes. We explained the difference in these two series models' performance from the relationship between some parameter of the leaves' biochemistry (chlorophyll, moisture, etc) and yield, the drought tolerance identification indexes.

Effects of irrigation and nitrogen on the performance of aerobic rice in northern China.

Aerobic rice is a new production system in which specially-developed varieties are grown under non-flooded, non-puddled, and non-saturated soil conditions. In 2003-2004, irrigation x Nitrogen experiments were carried out near Beijing using variety HD297. Water treatments included four irrigation levels, and Nitrogen treatments included different fertilizer N application rates and different numbers of N splits. The highest yields were 4 460 kg/ha with 688 mm of total (rain plus irrigation) water input in 2003 and 6 026 kg/ha with 705 mm of water input in 2004. Because of the quite even distribution of rainfall in both years, the four irrigation treatments did not result in large differences of soil water conditions. There were few significant effects of irrigation on biomass accumulation, but yield increased with the total amount of water applied. High yields coincided with high harvest index and high percentages of grain filling. The application of fertilizer N either reduced biomass and yield or kept it at the same level as 0 N and consistently reduced the percentage grain filling and 1 000-grain weight. With the highest water application, five splits of N gave higher yield than three splits, whereas three splits gave higher yield than five splits with lower water applications.