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The combination of phosphorothioate-modified primer and high-fidelity DNA polymerase constitute a mutation sensitive on/off switch. Herein, a modified mutation-sensitive on/off switch was designed with an extra point mutation at 5′ far away from the 3′ of the phosphorothioate modified primer to test the power of the new enzymes: Phusion, Q5 and Phanta UC polymerases. A modified on/off switch with the introduction of an extra point mismatched nucleotide at –8 from the 3′ terminus, and the use of Phanta UC Super-fidelity DNA polymerase has been confirmed to be highly sensitive and specific as compared to those without the 5′ artificial mismatched nucleotide, when applied in circulating tumor DNA (ctDNA) analysis of BRAF hotspot mutation.

A primerless amplification suitable for enrichment of particular genotype cfDNA which is a one-dimensional material has been developed. This primerless amplification coordinated by two thermostable enzymes of endonuclease and proofreading polymerase, functions as a genotype switch in analyzing cfDNA. The endonuclease digests the wild-typed fragments into mega-primer and discriminately destroys the wild-type DNA alleles. The DNA polymerase proofreads the megaprimer and then extends the mega-primer using the mutant DNA as the template. The prototypes of this technology were applied to two hotspot mutations of APC and EGFR with confirmed by DNA sequencing analysis. Genotype switch was then employed to clinical cfDNA assay targeting PIK3CA. Data from the clinical application suggest its potential in early cancer diagnosis.

Two cancer cell growth inhibitory esters, 1,2-dipalmitoyl-3-glucosyl glycerol (1) and 1,6-dihydroxy-hexane-bis-palmitoyl ester (2), together with arachidic acid-2-hydroxy-glycerol ester, daucosterol, and oleanolic acid, were isolated from the roots of Peucedanum ledebourielloides (Apiaceae family). The structures were determined by spectroscopic analyses. The esters 1 and 2 displayed significant activity against the SGC-7901, HT-29, and HL-60 cancer cell lines.

Evidences indicate that a complex relationship exists among sleep disorders, obesity and insulin resistance. NEU-P11 is a novel melatonin agonist used in treatment of psychophysiological insomnia, and in animal studies NEU-P11 showed sleep-promoting effect. In this study, we applied NEU-P11 on obese rats to assess its potential melatoninergic effects in vivo. Obese models were established using high-fat/high-sucrose-fed for 5 months. NEU-P11 (10 mg/kg)/melatonin (4 mg/kg)/vehicle were administered by a daily intraperitoneal injection respectively for 8 weeks. Our results showed that NEU-P11 or melatonin inhibited both body weight gain and deposit of abdominal fat with no influence on food intake. The impaired insulin sensitivity and antioxidative potency were improved and the levels of plasma glucose, total cholesterol (TC), triglycerides (TG) decreased with an increased in HDL-cholesterol (HDL-c) after NEU-P11 or melatonin administration. These data suggest that NEU-P11, like melatonin, decreased body weight gain and improved insulin sensitivity and metabolic profiles in obese rats. We conclude that NEU-P11 has a melatoninergic effect on regulating body weight in obese rats and also improving metabolic profiles and efficiently enhancing insulin sensitivity.

The synthetic compound NO-1886 is a lipoprotein lipase activator that has been proven to be highly effective in lowering plasma triglycerides and elevating high-density lipoprotein cholesterol. Recently, we found that NO-1886 also had a plasma glucose-reducing action in high-fat/high-sucrose diet-induced diabetic rabbits. In the current study, we investigated the effects of NO-1886 on the morphology of adipocytes, plasma levels of tumor necrosis factor-alpha (TNF-alpha) and free fatty acids (FFA) in miniature pigs fed a high-fat/high-sucrose diet. Our results showed that feeding a high-fat/high-sucrose diet to miniature pigs increased the size of adipocytes, and the plasma levels of TNF-alpha, FFA, and glucose. This diet also induced insulin resistance and impaired the acute insulin response to glucose loading. Supplementing 1% NO-1886 to the high-fat/high-sucrose diet inhibited adipocyte enlargement, and suppressed plasma levels of TNF-alpha, FFA, and glucose. The decrease in plasma TNF-alpha and FFA was simultaneous with the decrease in plasma glucose. We also found an increased whole body glucose clearance and an increased acute insulin response to intravenous glucose loading by NO-1886 supplementation. These data suggest that NO-1886 improves the glucose metabolism in high-fat/high-sucrose diet-induced diabetic minipigs by decreasing fat deposit, and suppressing plasma TNF-alpha and FFA levels. Therefore, NO-1886 is potentially beneficial for the treatment of insulin-resistant syndrome.

The role of microRNA-195 in developing acquired drug resistance in hepatocellular carcinoma cells was investigated. Expression profiling of miRNAs revealed a limited set of miRNAs with altered expression in drug resistant hepatocellular carcinoma cell line BEL-7402/5-FU compared to its parental BEL-7402 cell line. Real-time PCR confirmed down-regulation of miRNA-195 in BEL-7402/5-FU cells. Overexpression of miRNA-195 sensitized BEL-7402/5-FU cells to anticancer drugs. Consistent with these findings, miR-195 antisense oligonucleotide induced drug resistance in BEL-7402/5-FU cells. Also, the basal levels of the anti-apoptotic protein Bcl-w were high in BEL-7402/5-FU cells and miR-195 overexpression repressed Bcl-w protein level and inhibited the luciferase activity of a Bcl-w 3' untranslated region-based reporter construct in both BEL-7402/5-FU and BEL-7402 cells. These results indicate that miR-195 could improve the drug sensitivity at least in part by targeting Bcl-w to increase cell apoptosis in hepatocellular carcinoma cells.

[Purpose] To apply the “on/off” switch of 3′ exonuclease in single base discrimination of L191P and F275S mutations in gene KCNQ1 which are the mutations found in Chinese patients of LQTS. [Methods] A large amount of templates of wild type and mutation type were prepared by primer extension performed using polymerases without 3′ exonuclease activity respectively. Allelic specific primers targeting wild type and mutation type templates were desgined with 3′ terminal phosphorothioate modification. Two-directional primer extension was performed using polymerases with 3′ exonuclease activity. [Results] Whether single PCR or multiplex PCR amplified by exo+ polymerase, allelic specific primers targeting wild type allele were extended while no products were generated from primers targeting point-mutated LQTS-related allele, and also allelic specific primers targeting point-mutated LQTS-related mutation type allele were extended while no products were generated from primers targeting wild type allele. [Conclusion] These data suggest that the “off-switch” mediated by exo+ polymerase is more reliable in the identification of LQTS mutation sites and the “on/off” switch has potential enormous application in the diagnosis of monogenic diseases.

Vascular smooth muscle cells (VSMCs) were prepared from thoracic aortas of male Sprague-Dawley rats by the explant method to observe VSMC proliferation via phosphoinositide 3 kinase (PI3K)/Akt signaling transduction pathway induced by apelin-13. Expression of PI3K, phospho-PI3K, phospho-Akt, ERK1/2, phospho-ERK1/2 and cyclin D1 was detected by western blot analysis. Results showed that apelin-13 promoted the expression of phospho-PI3K and phospho-Akt in dose- and timedependent manner. PI3K inhibitor LY294002 significantly decreased the expression of phospho-PI3K, phospho-Akt, phospho-ERK1/2, and cyclin D1 induced by apelin-13. The Akt inhibitor 1701-1 significantly diminished the expression of phospho-Akt, phospho-ERK1/2, and cyclin D1 stimulated by apelin-13. MTT assay results showed that PI3K inhibitor LY294002 and Akt inhibitor 1701-1 significantly inhibited the VSMC proliferation induced by apelin-13. Apelin-13 promoted VSMC proliferation through PI3K/Akt signaling transduction pathway.

A new steroid, 3 0, 16 alpha-dihydroxy-(5 alpha)-cholestan-21-oic acid, was isolated from the aerial parts of Selaginella pulvinata. Its structure was elucidated on the basis of spectral analysis. (c) 2007 Elsevier B.V. All rights reserved.