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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

MCF-7 human breast cancer cells release polypeptides related to insulin-like growth factor-I (IGF-I) and epidermal growth factor (EGF) into serum-free culture medium (CM). Treatment of MCF-7 cells with 17 beta-estradiol, which is required in vivo for MCF-7 tumor growth in the nude mouse and stimulates the MCF-7 growth rate in vitro, resulted in selectively enhanced growth factor activities in CM. Autostimulatory growth-promoting activity was elevated at least 2-fold, and EGF-like polypeptides were elevated 5-fold but IGF-I immunoreactivity was not elevated. Several species of estrogen-induced receptor-reactive EGF-like polypeptides, suggestive of high molecular weight transforming growth factor alpha, were detected after gel exclusion chromatography of CM extracted with 1 M acetic acid. A 30,000 mol wt peak of EGF receptor competing activity comigrated with a peak of autostimulatory and fibroblast-transforming activity. It is possible that estradiol stimulation of MCF-7 growth and/or tumor formation may depend on induction of EGF-related polypeptide growth factors. EGF-I- and EGF-related polypeptides may act together as autocrine or paracrine growth factors in breast cancer.
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PMID:Induction of epidermal growth factor-related polypeptides by 17 beta-estradiol in MCF-7 human breast cancer cells. 300 Jul 28

To determine whether neoplastic cervical lesions in women are associated with papillomavirus infections in their sexual partners, we used a colposcope to examine male sexual partners of women with cervical flat condyloma (294 cases) or cervical intraepithelial neoplasia (186 cases), before and after 5 percent acetic acid was applied to the penis and the anogenital area. Condylomata acuminata, papules, and macules were observed in 309 of the 480 men (64.4 percent). In 204 of them (42.5 percent), macules or slightly elevated papules were detected only after application of acetic acid. Condylomata acuminata or lesions showing histologic features of condyloma were found in 121 partners (41.2 percent) of women with condyloma, but in only 10 partners (5.4 percent) of women with cervical intraepithelial neoplasia. Penile lesions showing histologic features of intraepithelial neoplasia were found in 61 partners (32.8 percent) of women with cervical intraepithelial neoplasia, but in only 4 partners (1.4 percent) of women with flat condyloma. Thirty-six (60 percent) of the 60 macules or papules tested contained papillomavirus DNA sequences. Human papillomavirus types 16 and 33 were almost exclusively found in penile intraepithelial neoplasia. Type 6, type 11, and the recently recognized type 42 were found in lesions showing features of condyloma or minimal histologic changes. As yet uncharacterized papillomaviruses were found in 15 percent of the specimens. These data support the concept that cervical carcinomas and precancerous lesions in women may be associated with genital papillomavirus infection in their male sexual partners.
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PMID:High prevalence of papillomavirus-associated penile intraepithelial neoplasia in sexual partners of women with cervical intraepithelial neoplasia. 304 Dec 17

We investigated the effects of reconstituted basement membrane (a crude extract of the Engelbreth-Holm-Swarm tumor) on type 2 pneumocyte differentiation during long-term culture. Cells were derived from mature 29 d fetal rabbits. Morphology was studied by light and electron microscopy. On thin gel, the cells initially segregated into clumps; they were cuboidal with apical microvilli and contained lamellar bodies, but dedifferentiated by 8 d. On thick gel, epithelial cells associated into spherical clusters surrounding a central lumen. These alveolarlike structures persisted at least 22 d. The cells were cuboidal and had lamellar bodies and intercellular tight junctions; they exhibited polarity, with apical microvilli facing the lumen, basally located nuclei, and gel matrix abutting the basal surface. In contrast, cells cultured on plastic formed colonies, then a monolayer, but dedifferentiated 5-7 d after plating. [14C]Acetate was used to label newly synthesized phospholipids. The amount of disaturated phosphatidylcholine (DSPC), expressed as a percentage of total phosphatidylcholine (PC), was used as an indicator of surfactant lipid production; percentage DSPC synthesized by cells cultured on thick gel did not change significantly, from 55 +/- 3 at 3 d, to 63 +/- 2 at 22 d in culture. DSPC synthesized by cells cultured on plastic decreased from 57 +/- 1% at 3 d to 45 +/- 2% at 22 d (p less than 0.001), which is consistent with the morphologic evidence of dedifferentiation. Synthesis of total PC compared with total phospholipid did not vary with either time in culture or substrate. This study emphasizes the importance of a complex extracellular matrix for maintenance of type 2 pneumocyte differentiation. The system should prove useful for studying the interaction of these cells with basement membrane, including the role of events occurring at the cell surface in modulating expression of a differentiated phenotype.
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PMID:Fetal type 2 pneumocytes form alveolar-like structures and maintain long-term differentiation on extracellular matrix. 304 32

The success of adoptive immunotherapy using interleukin-2 (IL-2) and lymphokine-activated killer (LAK) cells in treating a percentage of patients with melanoma and renal cell carcinoma has provided impetus to research into both how to optimize this treatment as well as approaches into making immunotherapy in general more successful. As the question on how to optimize IL-2 dose, schedule, cell culture conditions, and other specifics of IL-2 plus LAK therapy are addressed in clinical trials, other approaches suggested by data from in vitro, animal, and the clinical studies using IL-2 are emerging into clinical trials. (table; see text) These include two major areas of focus at the present time: (1) the use of IL-2 +/- LAK in combination with a variety of agents which have been shown to be synergistic with it, including other biological response modifiers (such as interferons), agents which may act both as interferon inducers as well as by other mechanisms (poly-IC:LC and flavone-8-acetic acid), and chemotherapeutic agents (especially cyclophosphamide, doxorubicin and agents which have some activity against the disease being treated such as DTIC for melanoma), and (2) various approaches aimed at inducing and expanding tumor-specific immune cells which appear to have greater antitumor activity than LAK cells and which may be major contributors to the antitumor efficacy of IL-2 therapy. These approaches also have the potential benefit of inducing memory cells with a resultant long-term immune antitumor response. Approaches aimed at activating specific antitumor immune cells include the use of IL-2-expanded infiltrating lymphocytes from tumors, exposure of peripheral blood cells cultured in IL-2 to tumor cells to hopefully expand those with a specific antitumor response, and the use of tumor cell vaccines in conjunction with IL-2. In addition to approaches using activated and expanded LAK effectors or specific T cells, the potential role of activated (e.g. by gamma interferon) and expanded (e.g. by macrophage colony stimulating factor) macrophages in the adoptive immunotherapy of cancer remains an area of ongoing exploration both in preclinical studies and clinical trials. As a greater understanding of the antitumor mechanisms of IL-2 and LAK therapy and other forms of adoptive immunotherapy is achieved, therapeutic approaches can be defined which will maximize the ability to mediate the immune destruction of tumor cells.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Adoptive therapies: quo vadis? 307 May 30

The effect of topical application of PGE on induction of ODC in mouse epidermis was measured. When direct induction of ODC by TPA was blocked by also applying indomethacin, maximum ODC activity occurred only when PGE was applied simultaneously with TPA 4 1/2 hr before killing of the mice. If either TPA or PGE was applied at other times, ODC activity decreased substantially. Induction of ODC by mezerein was blocked by indomethacin but restored by PGE, as was observed with TPA, but induction by ethyl phenylpropiolate was not affected by indomethacin or PGE. DMBA did not cause a consistent increase in ODC activity, nor was its inductive action affected by indomethacin or PGE. However, another weak inducer, acetic acid, exhibited elevated ODC activity when PGE was also applied. Inhibition by topical retinoic acid of ODC induction by TPA was partially overcome in a dose-response fashion by PGE. The results indicate that at least 2 events, elevation of PGE and another independent event, are required for induction of ODC activity. It appears that TPA causes at least 4 independent events essential for tumor promotion. A model for the events in the 2-stage tumor promotion model is proposed.
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PMID:The role of prostaglandin E1 in ornithine decarboxylase induction by tumor promoters. 308 53

Immunoglobin (Ig) has been found to accumulate on P815Y (H-2d) and L5178Y (H-2d) tumor cells during progressive growth in syngeneic host DBA/2 mice. Density of the accumulated Ig per cell increases as the tumor grows while the tumor cells become resistant to lysis by ascitic syngeneic cytotoxic cells. Tumor cells grown in vivo coated with this specific Ig no longer bind significant amounts of antibodies against H-2D and H-2K antigens. The membrane-bound Ig reacts with a rabbit antimouse Fab and a rabbit antimouse IgM reagent, but it does not react with a rabbit antimouse IgG or IgA reagent. It binds specifically to tumor cell lines that are sensitive to the ascitic cytotoxic cells but not to resistant tumor cell lines. The membrane-bound Ig can be eluted from tumor cells with 3 M NaSCN or 0.2 M acetic acid. Binding studies indicate that this eluted Ig is not an anti-H-2D/K antibody, yet it immunoprecipitates H-2D/K antigens from NP40 lysates of P815Y cells. It is proposed that the Ig is directed against a tumor antigen that is physically associated with the H-2D/K antigens of the tumors.
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PMID:Novel tumor-specific antigen(s) response observed in a syngeneic lymphoma-bearing host. 312 Nov 77

Acetate and the long chain free fatty acid palmitate provoked a decrease in the rates of glutamine utilization and glutamate production in Ehrlich ascites tumor cells incubated with 0.5 mM glutamine. There was a cumulative effect with glucose on glutamine metabolism.
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PMID:Effect of palmitate, acetate and glucose on glutamine metabolism in Ehrlich ascites tumor cells. 313 99

Acetic acid, a very weak tumor promoter in the multistage mouse skin model for chemical carcinogenesis, was found to be very effective at enhancing cancer development, when applied during the progression phase of the model. Papilloma-bearing mice when repeatedly treated with acetic acid had a greater carcinoma incidence and a greater conversion of papillomas to carcinomas than vehicle treated mice. Selective cytotoxicity is discussed as a possible mechanism.
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PMID:Acetic acid, a potent agent of tumor progression in the multistage mouse skin model for chemical carcinogenesis. 314 Oct 42

To evaluate the carcinogenic potential of the phenoxyherbicide 2-methyl-4-chlorophenoxy-acetic acid (MCPA) in the crested newt, Triturus cristatus carnifex, a long-term study has been carried out exposing the animals by the percutaneous route. Two hundred adult newts were divided into one control and three experimental groups of 20 females and 30 males each. The control group was kept in tap water and the experimental groups were kept for 4 days a week in an aqueous solution of Agroxone 3, a commercial formulation of MCPA, at concentrations equivalent to 100, 200, and 400 ppm of the active ingredient. Treatment was continued for 1 year, after which all the animals were kept under observation for approximately another year. Surviving female newts were killed 22-24 months after the beginning of experimentation, whereas the male newts were killed after 28 months, at the end of 18 weeks of exposure to the tumour promoter 12-O-tetradecanoylphorbol-13-acetate. Under experimental conditions, there was no carcinogenic activity of MCPA. Putative preneoplastic nodules of the liver and tumor-like lesions of the lower jaw were occasionally observed among the animals that survived more than 22 months after the beginning of experimentation. However, no significant differences in frequency between control and experimental groups were found.
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PMID:Evaluation of the carcinogenic risk of the phenoxyherbicide MCPA to an urodele amphibian. 323 84

A canine gliosarcoma model was used to study the effectiveness of magnetic resonance imaging (MRI) with gadolinium contrast enhancement in defining the histologic margins of brain tumors. The effectiveness of this technique was compared to conventional computed tomography (CT) using iodinated contrast enhancement. Cultured canine gliosarcoma cells were injected into the left hemisphere of adult mongrel dogs. The dogs developed brain tumors and progressive clinical signs. Serial MRI with and without gadolinium diethylene triamine penta-acetic acid was compared to serial CT with and without sodium iothalamate obtained on the same days. After the final scans, animals were sacrificed; the brains were removed and processed for routine histopathologic study. All tumors were visualized with contrast-enhanced MRI which proved most sensitive. Gadolinium di-ethylene triamine penta-acetic acid caused bright enhancement of tumors in a distribution that consistently corresponded to areas of pathologically proved tumor infiltration. Gross and microscopic autopsy findings correlated better with MRI than with CT which tended to produce poorer resolution and underrepresent the size of viable tumor. Gadolinium-enhanced MRI is more accurate than unenhanced MRI, unenhanced CT, or enhanced CT in defining the histologic margins of tumors.
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PMID:Comparison of CT and MRI brain tumor imaging using a canine glioma model. 324 30


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