A new cytotoxic, DNA interstrand crosslinking agent, 5-(aziridin-1-yl)-4-hydroxylamino-2-nitrobenzamide, is formed from 5-(aziridin-1-yl)-2,4-dinitrobenzamide (CB 1954) by a nitroreductase enzyme in walker carcinoma cells

1988 ◽  
Vol 37 (24) ◽  
pp. 4661-4669 ◽  
Author(s):  
Richard J. Knox ◽  
Frank Friedlos ◽  
Michael Jarman ◽  
John J. Roberts
Keyword(s):  
Crosslinking Agent ◽  
Carcinoma Cells ◽  
Walker Carcinoma ◽  
Interstrand Crosslinking

scholarly journals CELLULAR INJURY IN VITRO: PHASE CONTRAST STUDIES ON INJURED CYTOPLASM

1962 ◽  
Vol 14 (3) ◽  
pp. 401-420 ◽  
Author(s):  
I. K. Buckley
Keyword(s):  
Endoplasmic Reticulum ◽  
Enzyme Inhibitors ◽  
Acinar Cells ◽  
Carcinoma Cells ◽  
Secretion Granules ◽  
Fluid Collections ◽  
Walker Carcinoma ◽  
Myelin Figure ◽  
Myelin Figures

Unfixed, compressed acinar cells of rat pancreas, isolated by mechanical and enzymatic means, were examined by phase microscopy and photomicrographed using 35 mm film and electronic flash illumination. Similarly, observations were made on Walker carcinoma cells; in addition, these cells were treated with solutions containing either phosphatidase A or enzyme inhibitors. Acinar cells contained, besides nuclei, perinuclear droplets and secretion granules, various membranous and vacuolar structures. The basal cytoplasm showed parallel dark lines interpreted as endoplasmic reticulum. In some cells, fragmentation of the reticulum was followed by the direct incorporation of fragments into simple myelin figures. In other cells it appeared that phase-lucent linear structures and vacuoles were derived by dilatation of cisternae of the endoplasmic reticulum. Perinuclear fluid collections arose either by dilation of the perinuclear cisternae of the endoplasmic reticulum or by fluid dilatation of the nuclear envelope. Phosphatidase A disrupted early vacuoles of Walker carcinoma cells. From this and the direct involvement of elements of the endoplasmic reticulum in myelin figures, it was concluded that the membranes limiting the endoplasmic reticulum incorporate phosphatides in continuous layers. While many severely injured cells formed large vacuoles, others developed concentrically laminated myelin figures; it was concluded that both types of structure derived from phosphatides liberated intracellularly, the vacuoles by vesicular myelin figure formation.

scholarly journals hSnm1 Colocalizes and Physically Associates with 53BP1 before and after DNA Damage

2002 ◽  
Vol 22 (24) ◽  
pp. 8635-8647 ◽  
Author(s):  
Christopher T. Richie ◽  
Carolyn Peterson ◽  
Tao Lu ◽  
Walter N. Hittelman ◽  
Phillip B. Carpenter ◽  
...  
Keyword(s):  
Dna Damage ◽  
Ionizing Radiation ◽  
Cellular Response ◽  
Alkylating Agents ◽  
Crosslinking Agent ◽  
Physical Interaction ◽  
Nuclear Staining ◽  
Focus Formation ◽  
Before And After ◽  
Interstrand Crosslinking

ABSTRACT snm1 mutants of Saccharomyces cerevisiae have been shown to be specifically sensitive to DNA interstrand crosslinking agents but not sensitive to monofunctional alkylating agents, UV, or ionizing radiation. Five homologs of SNM1 have been identified in the mammalian genome and are termed SNM1, SNM1B, Artemis, ELAC2, and CPSF73. To explore the functional role of human Snm1 in response to DNA damage, we characterized the cellular distribution and dynamics of human Snm1 before and after exposure to DNA-damaging agents. Human Snm1 was found to localize to the cell nucleus in three distinct patterns. A particular cell showed diffuse nuclear staining, multiple nuclear foci, or one or two larger bodies confined to the nucleus. Upon exposure to ionizing radiation or an interstrand crosslinking agent, the number of cells exhibiting Snm1 bodies was reduced, while the population of cells with foci increased dramatically. Indirect immunofluorescence studies also indicated that the human Snm1 protein colocalized with 53BP1 before and after exposure to ionizing radiation, and a physical interaction was confirmed by coimmunoprecipitation assays. Furthermore, human Snm1 foci formed after ionizing radiation were largely coincident with foci formed by human Mre11 and to a lesser extent with those formed by BRCA1, but not with those formed by human Rad51. Finally, we mapped a region of human Snm1 of approximately 220 amino acids that was sufficient for focus formation when attached to a nuclear localization signal. Our results indicate a novel function for human Snm1 in the cellular response to double-strand breaks formed by ionizing radiation.

Endothelium stimulating factor from Walker carcinoma cells

1979 ◽  
Vol 119 (1) ◽  
pp. 181-190 ◽  
Author(s):  
B.R. McAuslan ◽  
H. Hoffman
Keyword(s):  
Carcinoma Cells ◽  
Walker Carcinoma ◽  
Stimulating Factor
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