Qian Zhao

Phosphodiester oligodeoxynucleotides bearing a 5' cholesteryl (chol) modification bind to low density lipoprotein (LDL), apparently by partitioning the chol-modified oligonucleotides into the lipid layer. Both HL60 cells and primary mouse spleen T and B cells incubated with fluorescently labeled chol-modified oligonucleotide showed substantially increased cellular association by flow cytometry and increased internalization by confocal microscopy compared to an identical molecule not bearing the chol group. Cellular internalization of chol-modified oligonucleotide occurred at least partially through the LDL receptor; it was increased in mouse spleen cells by cell culture in lipoprotein-deficient medium and/or lovastatin, and it was decreased by culture in high serum medium. To determine whether chol-modified oligonucleotides are more potent antisense agents, we titered antisense unmodified phosphodiester and chol-modified oligonucleotides targeted against a mouse immunosuppressive protein. Murine spleen cells cultured with 20 microM phosphodiester antisense oligonucleotides had a 2-fold increase in RNA synthesis, indicating the expected lymphocyte activation. Antisense chol-modified oligonucleotides showed an 8-fold increase in relative potency: they caused a 2-fold increase in RNA synthesis at just 2.5 microM. The increased efficacy was blocked by heparin and was further increased by cell culture in 1% (vs. 10%) fetal bovine serum, suggesting that the effect may, at least in part, be mediated via the LDL receptor. Antisense chol-modified oligonucleotides are sequence specific and have increased potency as compared to unmodified oligonucleotides.

AIMS: To examine the incidence of cardiovascular disease (CVD) and mortality in China and in key subpopulations, and to estimate the population-level risks attributable to 12 common modifiable risk factors for each outcome. METHODS AND RESULTS: In this prospective cohort of 47 262 middle-aged participants from 115 urban and rural communities in 12 provinces of China, it was examined how CVD incidence and mortality rates varied by sex, by urban-rural area, and by region. In participants without prior CVD, population-attributable fractions (PAFs) for CVD and for death related to 12 common modifiable risk factors were assessed: four metabolic risk factors (hypertension, diabetes, abdominal obesity, and lipids), four behavioural risk factors (tobacco, alcohol, diet quality, and physical activity), education, depression, grip strength, and household air pollution. The mean age of the cohort was 51.1 years. 58.2% were female, 49.2% were from urban areas, and 59.6% were from the eastern region of China. The median follow-up duration was 11.9 years. The CVD was the leading cause of death in China (36%). The rates of CVD and death were 8.35 and 5.33 per 1000 person-years, respectively, with higher rates in men compared with women and in rural compared with urban areas. Death rates were higher in the central and western regions of China compared with the eastern region. The modifiable risk factors studied collectively contributed to 59% of the PAF for CVD and 56% of the PAF for death in China. Metabolic risk factors accounted for the largest proportion of CVD (PAF of 41.7%), and hypertension was the most important risk factor (25.0%), followed by low education (10.2%), high non-high-density lipoprotein cholesterol (7.8%), and abdominal obesity (6.9%). The largest risk factors for death were hypertension (10.8%), low education (10.5%), poor diet (8.3%), tobacco use (7.5%), and household air pollution (6.1%). CONCLUSION: Both CVD and mortality are higher in men compared with women, and in rural compared with urban areas. Large reductions in CVD could potentially be achieved by controlling metabolic risk factors and improving education. Lowering mortality rates will require strategies addressing a broader range of risk factors.

It is hypothesized in this study that the phenomenon of environmental stress cracking (ESC) in polyetherurethane is caused by a synergistic action of biological components in the body fluids, oxidative agents, and stress. An in vitro system is designed to mimic the in vivo system; human plasma contains certain biological components that can act as a stress cracking promoter, while H2O2 (Co) solution provides an oxidative reaction comparable to that observed in the respiratory burst of adherent macrophages and foreign-body giant cells. It is demonstrated that the phenomenon of in vivo stress cracking in Pellethane 2363-80A is duplicated by an in vitro system that involves a pretreatment of prestressed specimens with human plasma at 37 degrees C for 7 days followed by oxidation in 10% hydrogen peroxide with 0.10M cobalt chloride at 50 degrees C for 10 days. The pretreatment with plasma has a synergistic effect with the oxidation by H2O2 (Co) treatment to produce ESC. A plasma component responsible for promoting stress cracking in Pellethane polyurethane is identified to be alpha 2-macroglobulin (alpha 2M).

The metastasis suppressor, N-myc downstream regulated gene 1 (NDRG1), is negatively correlated with tumor progression in multiple neoplasms, being a promising new target for cancer treatment. However, the precise molecular effects of NDRG1 remain unclear. Herein, we summarize recent advances in understanding the impact of NDRG1 on cancer metastasis with emphasis on its interactions with the key oncogenic nuclear factor-kappaB, phosphatidylinositol-3 kinase/phosphorylated AKT/mammalian target of rapamycin and Ras/Raf/mitogen-activated protein kinase kinase/extracellular signal-regulated kinase signaling pathways. Recent studies demonstrating the inhibitory effects of NDRG1 on the epithelial-mesenchymal transition, a key initial step in metastasis, TGF-β pathway and the Wnt/β-catenin pathway are also described. Furthermore, NDRG1 was also demonstrated to regulate molecular motors in cancer cells, leading to inhibition of F-actin polymerization, stress fiber formation and subsequent reduction of cancer cell migration. Collectively, this review summarizes the underlying molecular mechanisms of the antimetastatic effects of NDRG1 in cancer cells.