Multistage Carcinogenesis and the Biological Effects of Tumor Promoters

2018 ◽  
pp. 33-61
Author(s):  
Anne R. Kinsella
Keyword(s):  
Biological Effects ◽  
Tumor Promoters ◽  
Multistage Carcinogenesis

Oncogene-induced transformation of a rat embryo fibroblast cell line is enhanced by tumor promoters

1986 ◽  
Vol 6 (6) ◽  
pp. 1943-1950
Author(s):  
W L Hsiao ◽  
T Wu ◽  
I B Weinstein
Keyword(s):  
Cell Line ◽  
Fold Increase ◽  
Fibroblast Cell ◽  
Tumor Promoters ◽  
Fibroblast Cell Line ◽  
Ras Oncogene ◽  
Rat Embryo ◽  
Synergistic Interactions ◽  
Multistage Carcinogenesis ◽  
System Tumor

Rat embryo fibroblast cell line 6 was transfected with plasmid pT24, which contains the activated human bladder c-Ha-ras oncogene, and the cells were grown continuously in the absence or presence of the tumor promoters 12-O-tetradecanoyl phorbol-13-acetate (TPA) or teleocidin. The presence of TPA or teleocidin led to a 6- to 14-fold increase in the number of morphologically transformed foci. No transformed foci were seen when rat 6 cells were transfected with the normal c-Ha-ras oncogene in the absence or presence of TPA, or in cells simply treated with TPA or teleocidin. Enhancement of pT24-induced foci was seen even when the addition of TPA was delayed until day 16. In transfection studies with the drug resistance genes gpt and neo, TPA and teleocidin did not increase the number of Gpt+ or Neo+ colonies. When rat 6 cells were cotransfected with pT24 and neo genes and grown in the absence or presence of TPA, the presence of TPA did not increase the yield of Neo+ colonies but caused a fivefold increase in the number of Neo+ colonies that displayed a transformed morphology. Southern blot analyses of DNAs obtained from these clones indicated that TPA treatment did not influence the extent of integration of either the pT24 or neo gene. DNA samples from all of the morphologically transformed cells displayed a characteristic 2-kilobase SacI fragment homologous to pT24 DNA and expressed relatively high levels of the corresponding mRNA. Our findings indicate that in this system tumor promoters do not simply enhanced the process of DNA transfection per se. Thus, this model system may be useful for analyzing synergistic interactions between tumor promoters and activated oncogenes during multistage carcinogenesis. It may also serve as a simple screening test for detecting new tumor promoters.

scholarly journals Oncogene-induced transformation of a rat embryo fibroblast cell line is enhanced by tumor promoters.

1986 ◽  
Vol 6 (6) ◽  
pp. 1943-1950 ◽  
Author(s):  
W L Hsiao ◽  
T Wu ◽  
I B Weinstein
Keyword(s):  
Cell Line ◽  
Fold Increase ◽  
Fibroblast Cell ◽  
Tumor Promoters ◽  
Fibroblast Cell Line ◽  
Ras Oncogene ◽  
Rat Embryo ◽  
Synergistic Interactions ◽  
Multistage Carcinogenesis ◽  
System Tumor

Rat embryo fibroblast cell line 6 was transfected with plasmid pT24, which contains the activated human bladder c-Ha-ras oncogene, and the cells were grown continuously in the absence or presence of the tumor promoters 12-O-tetradecanoyl phorbol-13-acetate (TPA) or teleocidin. The presence of TPA or teleocidin led to a 6- to 14-fold increase in the number of morphologically transformed foci. No transformed foci were seen when rat 6 cells were transfected with the normal c-Ha-ras oncogene in the absence or presence of TPA, or in cells simply treated with TPA or teleocidin. Enhancement of pT24-induced foci was seen even when the addition of TPA was delayed until day 16. In transfection studies with the drug resistance genes gpt and neo, TPA and teleocidin did not increase the number of Gpt+ or Neo+ colonies. When rat 6 cells were cotransfected with pT24 and neo genes and grown in the absence or presence of TPA, the presence of TPA did not increase the yield of Neo+ colonies but caused a fivefold increase in the number of Neo+ colonies that displayed a transformed morphology. Southern blot analyses of DNAs obtained from these clones indicated that TPA treatment did not influence the extent of integration of either the pT24 or neo gene. DNA samples from all of the morphologically transformed cells displayed a characteristic 2-kilobase SacI fragment homologous to pT24 DNA and expressed relatively high levels of the corresponding mRNA. Our findings indicate that in this system tumor promoters do not simply enhanced the process of DNA transfection per se. Thus, this model system may be useful for analyzing synergistic interactions between tumor promoters and activated oncogenes during multistage carcinogenesis. It may also serve as a simple screening test for detecting new tumor promoters.

scholarly journals Analysis of Phorbolester Content During Growth and Development of Jatropha curcas Fruits

KnE Energy ◽  
2015 ◽  
Vol 1 (1) ◽  
pp. 125
Author(s):  
Randi Abdur Rohman ◽  
Dwi Yono ◽  
Nurita Toruan-Mathius ◽  
Roy Hendroko
Keyword(s):  
Phosphoric Acid ◽  
Jatropha Curcas ◽  
Growth And Development ◽  
Mobile Phase ◽  
Animal Feed ◽  
Biological Effects ◽  
Tumor Promoters ◽  
Toxic Compounds ◽  
Ester Content ◽  
High Level

<p>Utilization of Jatropha curcas seed meal as animal feed is limited by the presence of toxic compounds. Phorbolester present in Jatropha curcas as a family of compounds known to cause a large number of biological effects such as tumor promoters. The aim of this research is measure phorbolester content during growth and development of Jatropha curcas fruit. Phorbolester extracted by sonification method and analysed by UPLC using phosphoric acid and acetonitrile as mobile phase. Jatropha curcas fruit has ripe in the fifth week because of yellowing of fruit capsule. Toxic genotypes of Jatropha curcas has higher phorobol ester content than non-toxic genotypes approximately 182.1 and 55.2 ng/g respectively. Fruit capsule (122.2 ng/g) has higher phorbolester content than fruit seed (115.2 ng/g). It is due to biosynthesis of diterpene that occur in plastid. Biosynthesis of phorbolester possibly occured in initiation and maturation of fruit because the high level of phorbolester occur in the first and fifth week.</p><p><strong>Keywords:</strong> Jatropha curcas, toxic genotypes, non-toxic genotypes, fruit seed, fruit capsule</p>

Ultrastructural Changes in Three Different Mammalian Cells Following Ultraviolet Laser Irradiation

1972 ◽  
Vol 30 ◽  
pp. 350-351
Author(s):  
K. Shankar Narayan ◽  
Kailash C. Gupta ◽  
Tohru Okigaki
Keyword(s):  
Ultraviolet Light ◽  
Mammalian Cells ◽  
Biological Effects ◽  
Survival Rates ◽  
Chinese Hamster ◽  
Cell Types ◽  
Differential Sensitivity ◽  
Ultrastructural Changes ◽  
Ultraviolet Laser

The biological effects of short-wave ultraviolet light has generally been described in terms of changes in cell growth or survival rates and production of chromosomal aberrations. Ultrastructural changes following exposure of cells to ultraviolet light, particularly at 265 nm, have not been reported.We have developed a means of irradiating populations of cells grown in vitro to a monochromatic ultraviolet laser beam at a wavelength of 265 nm based on the method of Johnson. The cell types studies were: i) WI-38, a human diploid fibroblast; ii) CMP, a human adenocarcinoma cell line; and iii) Don C-II, a Chinese hamster fibroblast cell strain. The cells were exposed either in situ or in suspension to the ultraviolet laser (UVL) beam. Irradiated cell populations were studied either "immediately" or following growth for 1-8 days after irradiation.Differential sensitivity, as measured by survival rates were observed in the three cell types studied. Pattern of ultrastructural changes were also different in the three cell types.

Genomic analysis of C-type lectins

2002 ◽  
Vol 69 ◽  
pp. 59-72 ◽  
Author(s):  
Kurt Drickamer ◽  
Andrew J. Fadden
Keyword(s):  
Biological Effects ◽  
Cell Signalling ◽  
Genomic Analysis ◽  
Binding Activity ◽  
Immunoglobulin Superfamily ◽  
Carbohydrate Binding ◽  
Carbohydrate Recognition ◽  
Calcium Dependent ◽  
Binding Domains ◽  
Carbohydrate Recognition Domains

Many biological effects of complex carbohydrates are mediated by lectins that contain discrete carbohydrate-recognition domains. At least seven structurally distinct families of carbohydrate-recognition domains are found in lectins that are involved in intracellular trafficking, cell adhesion, cell–cell signalling, glycoprotein turnover and innate immunity. Genome-wide analysis of potential carbohydrate-binding domains is now possible. Two classes of intracellular lectins involved in glycoprotein trafficking are present in yeast, model invertebrates and vertebrates, and two other classes are present in vertebrates only. At the cell surface, calcium-dependent (C-type) lectins and galectins are found in model invertebrates and vertebrates, but not in yeast; immunoglobulin superfamily (I-type) lectins are only found in vertebrates. The evolutionary appearance of different classes of sugar-binding protein modules parallels a development towards more complex oligosaccharides that provide increased opportunities for specific recognition phenomena. An overall picture of the lectins present in humans can now be proposed. Based on our knowledge of the structures of several of the C-type carbohydrate-recognition domains, it is possible to suggest ligand-binding activity that may be associated with novel C-type lectin-like domains identified in a systematic screen of the human genome. Further analysis of the sequences of proteins containing these domains can be used as a basis for proposing potential biological functions.

INFLUENCE OF SPECIFIC ANTISERUM ON BIOLOGICAL EFFECTS OF HUMAN GONADOTROPHINS

1967 ◽  
Vol 56 (1_Suppl) ◽  
pp. S122
Author(s):  
P.-J. Czygan ◽  
D. Krebs ◽  
F. Lehmann ◽  
G. Bettendorf
Keyword(s):  
Biological Effects ◽  
Specific Antiserum
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