Relationship of βglucuronidaseto differentiation and invasion ofhuman colorectalcarcinoma

Objective To investigate the relationship between β glucuronidase and tumor differentiation and invasion in human colorectal carcinoma.Methods The expression of β glucuronidase in human colorectal carcinoma tissue was determined by streptavidin peroxidase immunohistochemical method. Four human colorectal carcinoma cell lines were analysed for β glucuronidase in the medium by spectrophotometry method.Results Compared with well differentiated colorectal carcinomas, β glucuronidase expression was higher in poorly differentiated tumors. An association was found between β glucuronidase overexpression in colorectal carcinoma and more advanced tumor Dukes' stage ( P <0.05). With increasing maximum depth of invasion, tumors more frequently show higher β glucuronidase expression (P<0.05). The analysis of colorectal carcinoma cell lines for β glucuronidase showed that low levels of β glucuronidase (activity range, 1.29 to 1.96?μg/10 6 cells per hour) were associated with the well differentiated cell lines which have low invasiveness (CX1, CCL187), and this was in contrast to the elevated level of the enzyme (2.46 to 2.73?μg/10 6 cells per hour) present in the medium derived from the poorly differentiated cells with high invasiveness (CCLl227,CCL228) (P< 0.05). Conclusions Poorly differentiated human colorectal carcinoma cells could synthesize more β glucuronidase, enhance local invasion. Immunohistochemical staining for β glucuronidase might be helpful to diagnosing the differentiation degree and invasiveness of human colorectal carcinomas, and the secreted β glucuronidase might provide a useful measurement of the differentiation degree and invasiveness of cultured human colorectal carcinoma cells.

Enzymatic treatment of estrogens and estrogen glucuronide

Natural and synthetic estrogens from sewage treatment systems are suspected to influence the reproductive health of the animals in the rivers. In this article, we investigated the enzymatic treatment of three estrogens （estrone, 17β-estradiol, and 17α-ethynyletstradiol） by a fungal laccase which oxidize phenolic compounds with dissolved oxygen. The elimination of the estrogenic activities by enzymatic oxidation was demonstrated by medaka vitellogenin assay. In addition, we developed an enzymatic treatment system comprised of β-D-glucuronidase and the laccase for 17β-estradiol 3-（β-D-glucuronide） degradation. The two enzymes eliminated 17β-estradiol 3-（β- D-glucuronide） and the intermediate, 17β-estradiol, efficiently.

Molecular cloning and characterization of fruit specific promoter from <i>Cucumis sativus</i>L.

The isolation and characterization of fruit specific promoters are critical for the manipulation of nutritional value and agronomic quality of fruits by genetic engineering and also opened a new era in edible vaccine technology. Expansins are proteins that induce loosening of individual plant cells by disrupting the non-covalent interactions between cellulose and hemicellulose microfibrils and hence have role in growth programs including fruit ripening. We report the identification of an expansin gene (CsExp) from Cucumis sativus that exhibits high levels of mRNA abundance and is specifically expressed in ripened fruit. The promoter region of CsExp also contains elements responsible for its fruit specific expression. Transient expression studies of the CsExp promoter were conducted with particle bombardment, followed by GUS histochemical assay and real time PCR. CaMV35S promoter was used as the positive control in all these experiments. Clear fruit specificity was observed for CsExp promoter in all the experiments. Thus CsExp promoter from Cucumber is a good candidate to target expression of the foreign genes to engineer fruit specific traits.

Increase of Expression Levels of Reporter Gene in Transgenic Tobaccos by Matrix Attachment Regions

The matrix attachment region (MAR) located downstream of Plastocyanin gene was isolated from the genome of pea. To study the effect of MARs on foreign gene expression in transgenic plants, T DNA vector was constructed in which MARs flanked bothβ glucuronidase(GUS) gene and selectable marker neomycin phosphotransferase (NPT II) gene. The plant expression vectors were transferred into leaf discs via Agrobacterium mediated transformation procedure. The result of GUS measurement showed that pea MAR could increase transgene expression level. The mean expression levels of GUS gene expression in population containing MARs could be increased twofold when compared with that of population without MARs.