The activity in vitro of four types of colicins (A, E1, E3, U) against one human standard fibroblast line and against 11 human tumor-cell lines carrying defined mutations of the p53 gene was quantified by MTT (tetrazolium bromide) assay. Flow cytometry showed that the pore-forming colicins A, E1 and U affected the cell cycle of 5 of these cell lines. Colicins E3 and U did not show any distinct inhibitory effects on the cell lines, while colicins E1 and especially A inhibited the growth of all of them (with one exception concerning colicin E1). Colicin E1 inhibited the growth of the tumor lines by 17-40% and standard fibroblasts MRC5 by 11%. Colicin A exhibited a differentiated 16-56% inhibition, the growth of standard fibroblasts being inhibited by 36%. In three of the lines, colicins A and E1 increased the number of cells in the G1 phase (by 12-58%) and in apoptosis (by 7-58%). These results correlated with the data from sensitivity assays. Hence, the inhibitory effect of colicins on eukaryotic cells in cell-selective, colicin-specific and can be considered to be cytotoxic.

• MeSH
• Cell Cycle drug effects   MeSH
• Eukaryotic Cells drug effects   MeSH
• Fibroblasts drug effects   MeSH
• G1 Phase drug effects   MeSH
• Colicins pharmacology   MeSH
• Humans MeSH
• Mutation MeSH
• Tumor Cells, Cultured drug effects   MeSH
• Tumor Suppressor Protein p53 genetics   MeSH
• Tetrazolium Salts metabolism   MeSH
• Thiazoles metabolism   MeSH
• Cell Survival drug effects   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Colicins MeSH
• Tumor Suppressor Protein p53 MeSH
• Tetrazolium Salts MeSH
• Thiazoles MeSH
• thiazolyl blue MeSH Browser