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A phorbol ester promoting agent, 12-O-tetradecanoyl-phorbol-13-acetate, enhances X-ray transformation in vitro in a two-stage fashion similar to that shown previously for ultraviolet radiation and chemical carcinogens. In studies with a mouse embryo-derived cell line (C3H/1OT 1/2 clone 8), there were clear interactive effects between X-radiation and(More)
The regulation of actin dynamics is pivotal for cellular processes such as cell adhesion, migration, and phagocytosis and thus is crucial for neutrophils to fulfill their roles in innate immunity. Many factors have been implicated in signal-induced actin polymerization, but the essential nature of the potential negative modulators are still poorly(More)
The clinical outcome of granulocyte transfusion therapy is often hampered by short ex vivo shelf life, inefficiency of recruitment to sites of inflammation, and poor pathogen-killing capability of transplanted neutrophils. Here, using a recently developed mouse granulocyte transfusion model, we revealed that the efficacy of granulocyte transfusion can be(More)
Scratching triggers skin flares in atopic dermatitis. We demonstrate that scratching of human skin and tape stripping of mouse skin cause neutrophil influx. In mice, this influx was largely dependent on the generation of leukotriene B4 (LTB4) by neutrophils and their expression of the LTB4 receptor BLT1. Allergic skin inflammation in response to(More)
When C3H/10T1/2 cells are treated with a given concentration of a chemical carcinogen, the transformation frequency can vary over 4 orders of magnitude, depending primarily upon the number of cells plated. To explain this phenomenon, we have developed a probabilistic theory of the formation of transformed foci in this system. We define p1 as the probability(More)
Ras guanine nucleotide exchange factor (GEF) Q, a nucleotide exchange factor from Dictyostelium discoideum, is a 143-kD protein containing RasGEF domains and a DEP domain. We show that RasGEF Q can bind to F-actin, has the potential to form complexes with myosin heavy chain kinase (MHCK) A that contain active RasB, and is the predominant exchange factor for(More)
The initiation and promotion stages of chemical oncogenesis have been demonstrated in cultured C3H/10T1/2 mouse embryo cells. Treatment of the cells with a subeffective concentration of 3-methylcholanthrene, benzo(a)pyrene, or 7,12-dimethylbenz(a)anthracene, followed 4 days later by a nontransforming amount of tetradecanoylphorbol acetate (TPA), phorbol(More)
Cell lines derived from C3H mouse ventral prostate grow to a monolayer, do not pile up, and do not give tumors on inoculation into isologous mice. When treated with carcinogenic hydrocarbons, these cells produce piledup colonies that give rise to fibrosarcomas in mice; these colonies are termed transformed. Individual single cells were treated with 0.5 per(More)
The effects of the tumor-promoting phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) on the morphology and growth properties of C3H/10T1/2 clone 8 cells were examined. The morphology of these cells was changed within 30 min following treatment with 0.1 microgram of TPA per ml; they became smaller and refractile with long beady processes. Such changes(More)
Impure and pure samples of saccharin (2 milligrams per milliliter) did not produce oncogenic transformation of C3H/10T1/2, clone 8, mouse embryo fibroblasts. However, after treatment of the cells with a nontransforming initiating dose (0.1 microgram per milliliter) of 3-methylcholanthrene, continuous treatment with either sample of saccharin (100 micrograms(More)