Cancer biochemistry biophysics最新文献_第3页

Cytotoxic effect of substitution at 2-, 6-, and 2,6-positions in ascorbic acid on malignant cell line. 抗坏血酸2-、6-和2- 6位取代对恶性细胞系的细胞毒作用。

Cancer biochemistry biophysics Pub Date : 1998-11-01

M W Roomi, D House, C S Tsao

{"title":"Cytotoxic effect of substitution at 2-, 6-, and 2,6-positions in ascorbic acid on malignant cell line.","authors":"M W Roomi, D House, C S Tsao","doi":"","DOIUrl":"","url":null,"abstract":"In recent years L-ascorbic acid (AA) and its isomers have raised considerable interest as anticancer agents, although the mechanism has remained largely unknown. AA isomers are nearly identical in their physical and chemical properties but differ widely in their biological properties. AA, a lactone sugar, has a number of reactive positions, especially at 2- and 6-. Although there are a number of reports on the cytotoxic effect of AA and its isomers on malignant and nonmalignant cell lines, no work has been reported on the comparative effects of substitutions at these active sites. This study, then, investigates the comparative cytotoxicity of such substitutes on the malignant leukemia P388 cell line in culture. We tested a series of 2-, 6- and 2,6- disubstituted AA-derivatives, comprising the following: i) substitution at 2-position: -PO4, -SO4, O-Me, O-octadecyl; ii) substitution at 6-position: -PO4, -SO4, -palmitate, -stearate; and iii) substitution at 2,6-position: -dipalmitate. About 50,000 P388 cells/ml were incubated with and without AA derivatives in a final concentration of 1000, 500, 100, 10 and 1 microg/ml in triplicate and counted after 72 hrs. All 2-substituted and the 2,6-substituted AA derivatives tested were nontoxic and ineffective in preventing cell growth. In contrast, all 6-substituted AA derivatives were very toxic at all levels, even at the lowest concentration. These results suggest that substitution at 2-, 6- and 2,6-positions in AA have a different effect on toxicity. The 2-, and 2,6-substituted AA derivatives are stable compounds, resistant to hydrolysis which render them inactive. The cytotoxicity of the 6-substituted derivatives may be explained by one of the following mechanisms, yet to be explored: i) the hydrolysis rate may differ; or ii) the chemical structure itself may affect toxicity. Further studies are in progress to understand the mechanism.","PeriodicalId":9552,"journal":{"name":"Cancer biochemistry biophysics","volume":"16 4","pages":"295-300"},"PeriodicalIF":0.0,"publicationDate":"1998-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20831291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The instability of polyhydroxylated aromatic protein tyrosine kinase inhibitors in the presence of manganese. 多羟基芳香蛋白酪氨酸激酶抑制剂在锰存在下的不稳定性。

Cancer biochemistry biophysics Pub Date : 1998-11-01

L Ramdas, R J Budde

引用次数: 0

Chemical, metabolic and immunological characterization of gangliosides of human glioma cells. 人胶质瘤细胞神经节苷类的化学、代谢和免疫学特性。

Cancer biochemistry biophysics Pub Date : 1998-11-01

Y Maeda, T Yamaki, J Yoshikawa, K Tatewaki, H Piao, H Yu, Y Ibayashi, K Hashi

{"title":"Chemical, metabolic and immunological characterization of gangliosides of human glioma cells.","authors":"Y Maeda, T Yamaki, J Yoshikawa, K Tatewaki, H Piao, H Yu, Y Ibayashi, K Hashi","doi":"","DOIUrl":"","url":null,"abstract":"The patterns of ganglioside profiles were studied in 10 human glioma and one melanoma cell lines. Ganglio-series gangliosides, GM3 (NeuAc alpha2-3Gal beta1-4Glc beta1-Cer) and GM2 (GalNAc beta 1-4 (NeuAc alpha2-3)Gal beta1-4Glc beta 1-1Cer), and a neolacto-series ganglioside, sialylparagloboside (SPG) (NeuAc alpha 2-3Gal beta1-4GlcNAc beta1-3Gal beta1-4Glc beta1-1Cer), were the predominant constituents. The activities of the two key enzymes, GM3 synthetase and lactotriaosyl ceramide (Lc3Cer) synthetase, alone did not account for the ganglioside profile. Metabolic labeling with the use of [3H]glucosamine-HCl showed more pronounced difference in the synthetic rate of each ganglioside type, in which GM2 was the most strongly labeled in 7 out of the 10 glioma cell lines. On quantifying the chemical content of GM3 and GM2, the GM3/GM2 molar ratio of above 2.0 was arbitrarily classified into GM3 dominant type (KG-1C and Mewo); the ratio below 0.5 was designated as GM2 dominant type (H4, U138MG, U373MG, T98G and A172); and the ratio between 0.5 and 2.0 was regarded as GM3 and GM2-co-dominant type (U87MG, Hs683, SW1088 and U118MG). Subsequently, the capabilities of the antibody binding to these gangliosides were examined in native forms in the cell membrane and in chemically-isolated forms. The intensity of reaction against chemically isolated GM3 and GM2 gangliosides was dependent on the quantity, and GM2 was more reactive than GM3; however, the reactivities on the cell surface did not correlate with the chemical content indicating other factors to influence their immunoreactivities.","PeriodicalId":9552,"journal":{"name":"Cancer biochemistry biophysics","volume":"16 4","pages":"313-32"},"PeriodicalIF":0.0,"publicationDate":"1998-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20831293","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Native fluorescence spectroscopy of normal and malignant epithelial cells. 正常和恶性上皮细胞的天然荧光光谱。

Cancer biochemistry biophysics Pub Date : 1998-11-01

S Ganesan, P G Sacks, Y Yang, A Katz, M Al-Rawi, H E Savage, S P Schantz, R R Alfano

引用次数: 0

Antioxidant potential of cancerous human kidney tissues. 人类癌变肾组织的抗氧化潜能。