Determination of sialidase activity in hepatocellular carcinoma (HCC) to complete the mechanism study of GD3 change in HCC. A sensitive assay for ganglioside sialidase activity was used based on the specific binding o...Determination of sialidase activity in hepatocellular carcinoma (HCC) to complete the mechanism study of GD3 change in HCC. A sensitive assay for ganglioside sialidase activity was used based on the specific binding of ricinus communis agglutinin Ⅱ (RCAⅡ) to lactose reside. The substrate used for sialidase assay was ganglioside GM3 coated on a 96- well microtiterplate. After removing static acids from the terminal positions of the ganglioside glycans by sialidase, the glycans were subjected to biotin-labeled RCAⅡ. Then, the ABC assay was used to determine the activity of sialidase. The activities of sialidase with both soluble form and membrane-bound form in HCC decreased significantly as compared with those in peritumor tissue. Our results indicated that the increase in ganglioside GD3 in HCC is not only due to the enhancement of GD3 sythase activity but also due to the decrease in the sialidase展开更多
Objective: To establish a method of non-isotope double in situ hybridization in order to detect the expression of two kinds of oncogenes at single cell level simultaneously, and confirm the hypothesis of 'model of...Objective: To establish a method of non-isotope double in situ hybridization in order to detect the expression of two kinds of oncogenes at single cell level simultaneously, and confirm the hypothesis of 'model of stepwise carcinogenesis'. Methods: The method of non-isotope double in situ hybridization was established with the digoxigenin (Dig) and biotin(Bio) labelled probes. The expression of two members of oncogenes of the myc and/or ras gene families (myc and N-ras, myc and K-ras, myc and H-ras, N-ras and K-ras , N-ras and H-ras, K-ras and H-ras) was further studied with the method in 10 cases of Chinese Hepatocellular Carcinomas (HCC). Results : Co-expression of two kinds of oncogenes was detected only in a few cases, reflected by coshowing two different hybridization signals ,i. e. , co-showing of Dig-myc and Bio-H-ras, Dig-myc and Bio-N-ras, Dig-myc and Bio-K-ras was observed in 2 cases, 2 cases and one case, respectively. The common characteristics were that positive cells of myc distributed diffusely, while positive cells of ras diatributed sporadically or locally among the positive cells of myc, and only a few cells exhibited co-showing of two oncogenes at single cell level. There were only 2 cases representing co-showing of two oncogenes in ras gene family (Dig-N-ras and bio-H-ras, Dig-N-ras and Bio-K-ras , respectively). The two kinds of positive cells of different ras gene represented mixed local and sporadical distribution, and co-showing of two signals was found in a few cells at single cell level. Conclusion: There are multiple oncogenes involving in tumorigenesis by their ordered activation. The activation of the ras gene family plays a role in promotion, while the activation of myc is an important event in late stage of tumorigenesis展开更多
Telomerase is a ribonucleoprotein enzyme, which synthesizes telomeric repeats (TTAGGG) n.While germline cells and most malignant tumor cells express telomerase activity, normal somatic cells aregenerally deficient in ...Telomerase is a ribonucleoprotein enzyme, which synthesizes telomeric repeats (TTAGGG) n.While germline cells and most malignant tumor cells express telomerase activity, normal somatic cells aregenerally deficient in telomerase activity. Our objective was to detect telomerase activity of human cells bysilver staining with telorneric repeat amplification protocol (TRAP) which is easy and quick. Comparing withradioisotopic TRAP, we examined the telomerase activity in telomerase-positive 293-cell and RNase-pretreated and heat-pretreated negative controls by silver staining TRAP. We detected telomerase activity in 2 strainsof human liver tumor cells (QGY7701 and SMMC7721 ). The 293 cells (only 10 cells) and the 2 strains ofhuman liver tumor cells were all positive. while telomerase activity was not detected in the negative controls.These data suggest that non-radioisotopic silver staining TRAP is a specific, sensitive and fast assay fortelomerase activity. It was verified that the 2 strains of human liver tumor cells express telomerase activity.展开更多
文摘Determination of sialidase activity in hepatocellular carcinoma (HCC) to complete the mechanism study of GD3 change in HCC. A sensitive assay for ganglioside sialidase activity was used based on the specific binding of ricinus communis agglutinin Ⅱ (RCAⅡ) to lactose reside. The substrate used for sialidase assay was ganglioside GM3 coated on a 96- well microtiterplate. After removing static acids from the terminal positions of the ganglioside glycans by sialidase, the glycans were subjected to biotin-labeled RCAⅡ. Then, the ABC assay was used to determine the activity of sialidase. The activities of sialidase with both soluble form and membrane-bound form in HCC decreased significantly as compared with those in peritumor tissue. Our results indicated that the increase in ganglioside GD3 in HCC is not only due to the enhancement of GD3 sythase activity but also due to the decrease in the sialidase
文摘Objective: To establish a method of non-isotope double in situ hybridization in order to detect the expression of two kinds of oncogenes at single cell level simultaneously, and confirm the hypothesis of 'model of stepwise carcinogenesis'. Methods: The method of non-isotope double in situ hybridization was established with the digoxigenin (Dig) and biotin(Bio) labelled probes. The expression of two members of oncogenes of the myc and/or ras gene families (myc and N-ras, myc and K-ras, myc and H-ras, N-ras and K-ras , N-ras and H-ras, K-ras and H-ras) was further studied with the method in 10 cases of Chinese Hepatocellular Carcinomas (HCC). Results : Co-expression of two kinds of oncogenes was detected only in a few cases, reflected by coshowing two different hybridization signals ,i. e. , co-showing of Dig-myc and Bio-H-ras, Dig-myc and Bio-N-ras, Dig-myc and Bio-K-ras was observed in 2 cases, 2 cases and one case, respectively. The common characteristics were that positive cells of myc distributed diffusely, while positive cells of ras diatributed sporadically or locally among the positive cells of myc, and only a few cells exhibited co-showing of two oncogenes at single cell level. There were only 2 cases representing co-showing of two oncogenes in ras gene family (Dig-N-ras and bio-H-ras, Dig-N-ras and Bio-K-ras , respectively). The two kinds of positive cells of different ras gene represented mixed local and sporadical distribution, and co-showing of two signals was found in a few cells at single cell level. Conclusion: There are multiple oncogenes involving in tumorigenesis by their ordered activation. The activation of the ras gene family plays a role in promotion, while the activation of myc is an important event in late stage of tumorigenesis
文摘Telomerase is a ribonucleoprotein enzyme, which synthesizes telomeric repeats (TTAGGG) n.While germline cells and most malignant tumor cells express telomerase activity, normal somatic cells aregenerally deficient in telomerase activity. Our objective was to detect telomerase activity of human cells bysilver staining with telorneric repeat amplification protocol (TRAP) which is easy and quick. Comparing withradioisotopic TRAP, we examined the telomerase activity in telomerase-positive 293-cell and RNase-pretreated and heat-pretreated negative controls by silver staining TRAP. We detected telomerase activity in 2 strainsof human liver tumor cells (QGY7701 and SMMC7721 ). The 293 cells (only 10 cells) and the 2 strains ofhuman liver tumor cells were all positive. while telomerase activity was not detected in the negative controls.These data suggest that non-radioisotopic silver staining TRAP is a specific, sensitive and fast assay fortelomerase activity. It was verified that the 2 strains of human liver tumor cells express telomerase activity.
