Epigallocatechin-3-gallate induces apoptosis,inhibits proliferation and decreases invasion of glioma cell

Epigallocatechin-3-gallate (EGCG), a major polyphenol in green tea, has been considered a potential therapeutic and chemopreventive agent for cancer. Glioma is a malignant tumor with high mortality but effective therapy has not yet been developed. In this study, we found that EGCG induced apoptosis in U251 glioma cells via the laminin receptor (molecular weight 67kDa) in a time- and dose-dependent manner, decreased their invasiveness and inhibited their proliferation. The mitogen-activated protein kinase pathway was shown to be involved in glioma cell apoptosis and proliferation. Furthermore, the mRNA levels of matrix metalloproteinase (MMP)-2 and MMP-9 were reduced after EGCG treatment. These results suggest that EGCG has important therapeutic effects with low toxicity and side-effects, and could be used in cancer chemoprevention.     

Axon guidance factor netrin-1 and its receptors regulate angiogenesis after cerebral ischemia

Neurogenesis and angiogenesis play important roles in functional recovery after ischemic stroke. When cerebral ischemia occurs, axon regeneration can compensate for the loss of apoptotic neurons in the ischemic area. The formation of new blood vessels ameliorates the local decrease in blood supply, enhancing the supply of oxygen and nutrients to newly-formed neurons. New blood vessels also act as a scaffold for the migration of neuroblasts to the infarct area after ischemic stroke. In light of this, researchers have been actively searching for methods to treat cerebral infarction. Netrins were first identified as a family of proteins that mediate axon guidance and direct axon migration during embryogenesis. Later studies have revealed other functions of this protein family. In this review, we focus on netrin-1, which has been shown to be involved in axon migration and angiogenesis, which are required for recovery after cerebral ischemia. Thus, therapies targeting netrin-1 may be useful for the treatment of ischemic stroke.     

Development of 39 novel polymorphic microsatellite markers for the giant mottled eel Anguilla marmorata and cross-amplification in other eel species

In this study, we have developed microsatellite markers for the giant mottled eel (Anguilla marmorata) from expressed sequence tag (EST) sequences using next-generation sequencing. Consequently, a total of 39 novel polymorphic microsatellite markers were identified in 32 individuals from Wangquan River wild population area. The range of observed heterozygosity, expected heterozygosity and polymorphism information content were 0.044–1.000, 0.285–0.946 and 0.3783–0.9016, respectively. In addition, eight loci were deviated from Hardy–Weinberg equilibrium and modified by Bonferroni correction, and the results showed no significant linkage disequilibrium between the locus pair. The amplification of cross-species was conducted in Anguilla bicolor pacifica and Anguilla japonica, which revealed the applicability of EST-SSR primers. These EST-SSR markers can provide sufficient polymorphism for population genetic studies, pedigree and genome mapping of these three kinds of closely related eels.     

Impact of Dietary Aromatic Amino Acids on Osteoclastic Activity

We had shown that aromatic amino acid (phenylalanine, tyrosine, and tryptophan) supplementation prevented bone loss in an aging C57BL/6 mice model. In vivo results from the markers of bone breakdown suggested an inhibition of osteoclastic activity or differentiation. To assess osteoclastic differentiation, we examined the effects of aromatic amino acids on early /structural markers as vitronectin receptor, calcitonin receptor, and carbonic anhydrase II as well as, late/functional differentiation markers; cathepsin K and matrix metalloproteinase 9 (MMP-9). Our data demonstrate that the aromatic amino acids down-regulated early and late osteoclastic differentiation markers as measured by real time PCR. Our data also suggest a link between the vitronectin receptor and the secreted cathepsin K that both showed consistent effects to the aromatic amino acid treatment. However, the non-attachment related proteins, calcitonin receptor, and carbonic anhydrase II, demonstrated less consistent effects in response to treatment. Our data are consistent with aromatic amino acids down-regulating osteoclastic differentiation by suppressing remodeling gene expression thus contributing initially to the net increase in bone mass seen in vivo.     

shRNA-mediated GSTP1 gene silencing enhances androgen-independent cell line DU145 chemosensitivity

Purpose

Design short hairpin RNA (shRNA) interference sequence to silence glutathione S-transferase P1 (GSTP1) gene of androgen-independent prostate cancer cell line DU145, and then to explore its effect on sensitivity to chemotherapeutics.

Methods

Target sequence was picked up to form the shRNA. DU145 cell was divided into five groups according to the shRNA added for transfection: shRNA255, shRNA554, shRNA593, negative-shRNA and blank group. Fluorescence microscope was used to pick up the shRNA with the highest transfection ratio. Western blotting and RT-PCR were taken to pick up the shRNA with the best gene silencing result. 3-(4,5-Dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide assay and terminal de-oxynucleotidyl transferase-mediated dUTP nick end-labeling assay were used to detect survival ratio and apoptosis ratio of DU145 administered of fluorouracil (5-FU) or paclitaxel (PA) at different concentrations before and after shRNA transfection.

Results

Three different shRNA oligonucleotides (shRNA255; shRNA554; shRNA593) targeting the coding sequence of GSTP1 mRNA and one negative control shRNA were constructed. The transfection ratio of shRNA554 (76.2 ± 0.68 %) was higher than that of shRNA255 (63.3 ± 1.04 %) (P < 0.01) or shRNA593 (72.7 ± 0.33 %) (P < 0.01). After transfection of shRNA554, the mRNA and protein of level were the lowest, P < 0.01. The survival ratio of DU145 administered with 5-FU of different concentrations (30, 60, 120, 240 μg/ml) declined after transfection (P < 0.01). Besides, the apoptosis ratio increased after transfection (P < 0.01). Similarly the survival ratio of DU145 administered with PA of different concentrations (0.2, 2, 10, 20 μg/ml) declined (P < 0.01) and the apoptosis ratio increased (P < 0.01) after transfection.

Conclusions

The gene GSTP1 silence via shRNA transfection to androgen-independent prostate cancer cell line DU145 enhances the sensitivity to chemotherapeutics.     

胎盘型谷胱甘肽S－转移酶在人乳腺癌的免疫组化检测

应用抗人胎盘型谷胱甘肽Ｓ－转移酶（ＧＳＴ－π）单克隆抗体，以微波ＬＳＡＢ免疫组化技术，检测了ＧＳＴ－π在人乳腺癌中的表达情况。１３２例乳腺癌中，７８．，８％（１０４／１３２）呈阳性表达。ＧＳＴ－π表达与患者年龄、肿瘤大小及腋窝淋巴结转移无明显相关，与组织学类型有一定关系，ＧＳＴ－π在ＥＲ（一）乳腺癌的阳性表达率９１．３％，显著高于ＥＲ（＋）者６４．４％（Ｐ＜０．０１），同样ＧＳＴ－π在ＰＲ（一）乳腺癌的阳性率８８．２％，也显著高于ＰＲ（＋）者６６．７％（Ｐ＜０．０５）。结果表明，ＧＳＴ－π的表达与乳腺癌发生、发展的关系密切，且与ＥＲ和ＰＲ的表达呈明显负相关，文中就其临床意义进行了讨论。