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Query: UMLS:C0596263 (carcinogenesis)
 64,820 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This investigation is part of an effort to develop chemoprevention for carcinogenesis of the lung. It focuses on the efficacy of low doses of synthetic glucocorticoids administered either as single agents or in combination with a second compound, myo-inositol. Glucocorticoids are potent inhibitors of carcinogenesis. The use of low doses is important to avoid potential side-effects. The synthetic glucocorticoid budesonide, administered by aerosol for 20 s three times a week, was studied to determine its effects on benzo[a]pyrene-induced pulmonary adenoma formation in female A/J mice. Two dose levels were employed, 10 and 25 microg/kg body wt. The lower dose produced a 34% reduction in lung tumor formation and the higher dose level a 60% reduction in lung tumors. In additional groups of mice, the effects of 0.3% myo-inositol added to the diet was found to reduce pulmonary tumor formation by 53%. The two agents given in combination resulted in a greater inhibition of lung tumor formation than either by itself. Budesonide at 10 microg/kg body wt plus 0.3% myo-inositol reduced the number of tumors by 60% and budesonide at 25 microg/kg body wt plus 0.3% myo-inositol reduced lung tumor formation by 79%. To determine whether a glucocorticoid other than budesonide would have inhibitory effects in this experimental model, beclomethasone dipropionate administered by aerosol for 20 s three times a week was studied as a single agent and showed almost identical inhibitory properties to budesonide. The doses of the glucocorticoids calculated on a daily basis are within the range of those used widely for control of chronic allergic respiratory diseases in the human. The capacity of low doses of inhaled glucocorticoids to prevent pulmonary neoplasia and the enhancement of this preventive effect by myo-inositol, an essentially non-toxic compound, are findings that should encourage further work to evaluate the applicability of these agents to the prevention of neoplasia of the lung in the human.
Carcinogenesis 2000 Feb
PMID:Chemoprevention of pulmonary carcinogenesis by brief exposures to aerosolized budesonide or beclomethasone dipropionate and by the combination of aerosolized budesonide and dietary myo-inositol. 1065 55

Chemopreventive drugs have the potential to decrease the morbidity and mortality of lung cancer. The development of these drugs could be expedited by the application of surrogate end-point biomarkers that demonstrate chemopreventive efficacy. In this study, the ability of budesonide to prevent lung tumors in mice was characterized further and its effects on biomarkers were determined. Lung tumors were induced in female strain A mice by vinyl carbamate (16 mg/kg) administered once weekly for 2 consecutive weeks. Four weeks later the mice started to receive 0.6, 1.2 or 2.4 mg/kg budesonide continually in the diet until killed at week 20. Budesonide caused a dose-dependent decrease in the multiplicity of lung tumors of 25, 58 and 82%, respectively. Budesonide (2.4 mg/kg diet) administered starting at weeks 4, 10 or 16, decreased tumor multiplicity by 82, 66 and 30% at week 20. Administering 2.4 mg/kg budesonide at weeks 4-20 or 20-35 and killing the mice at week 35 did not significantly decrease the yield of tumors, although both treatment regimens did decrease the size of the tumors and the progression of adenomas to carcinomas. Thus, budesonide delayed the appearance of lung tumors and decreased their growth and progression to carcinomas. To determine the effect of limited exposure to budesonide on biomarkers, it was administered for only 7 days prior to death at week 35. Budesonide decreased the proliferating cell nuclear antigen labeling in lung adenomas, carcinomas, parenchyma and bronchial airways by 87.6, 59.0, 41.1 and 25.4%, respectively. Budesonide treatment also increased the protein level of the p21 and p27 genes and increased the mRNA level of p21. Thus, short-term treatment with budesonide modulated biological and molecular end-points in lung tumors that might be developed further as biomarkers for its clinical chemopreventive efficacy in the lung.
Carcinogenesis 2002 Jul
PMID:Prevention of mouse lung tumors by budesonide and its modulation of biomarkers. 1211 77

Budesonide (an anti-inflammatory glucocorticoid), R115777 (a farnesyl transferase inhibitor, Zarnestra, Tipifarnib) or combinations of them were evaluated for prevention of lung tumors and for modulation of DNA methylation in tumors. Lung tumors were induced by vinyl carbamate in female Strain A mice. One week later, mice received 60 or 100 mg/kg R115777 by oral gavage and 5 days/week, 0.8 or 1.6 mg/kg of budesonide in their diet, or their combined treatment until killed at 20, 28 and 36 weeks after administering the vinyl carbamate. Other mice were administered the drugs for 2 weeks before killing at 20 weeks. At Week 20, the rank order for prevention of lung tumors was the combined treatment>budesonide>R115777. At later killings, R115777 was no longer effective, whereas budesonide and the combinations continued to prevent tumors, albeit at a reduced efficacy. DNA hypomethylation in lung tumors was prevented by treatment with R115777, budesonide and the combinations. When administered starting at Week 18 to tumor-bearing mice, the drugs reversed DNA hypomethylation in the tumors. In summary, combined treatment with budesonide and R115777 produced the following results: (i) it was more efficacious in preventing lung tumors than the individual drugs; and (ii) it prevented and reversed DNA hypomethylation in lung tumors. These results support the combined use of budesonide and R115777 in prevention of lung tumors and suggest that reversal of DNA hypomethylation in lung tumors would be useful as a surrogate endpoint biomarker for prevention.
Carcinogenesis 2006 Dec
PMID:Prevention of mouse lung tumors and modulation of DNA methylation by combined treatment with budesonide and R115777 (ZarnestraMT). 1673 49

Budesonide (an anti-inflammatory glucocorticoid), R115777 (a farnesyl transferase inhibitor, Zarnestra, Tipifarnib) or combinations of them were evaluated for prevention of lung tumors and for modulation of DNA methylation in tumors. Lung tumors were induced by vinyl carbamate in female strain A mice. One week later, mice received 60 or 100 mg/kg R115777 by oral gavage and 5 days/week, 0.8 or 1.6 mg/kg of budesonide in their diet, or their combined treatment until killed at 20, 28 and 36 weeks after administering the vinyl carbamate. Other mice were administered the drugs for 2 weeks before killing at Week 20. At Week 20, the rank order for prevention of lung tumors was the combined treatment > budesonide > R115777. At later killings, R115777 was no longer effective, whereas budesonide and the combinations continued to prevent tumors, albeit at a reduced efficacy. DNA hypomethylation in lung tumors was prevented by treatment with R115777, budesonide and the combinations. When administered starting at Week 18 to tumor-bearing mice, the drugs reversed DNA hypomethylation in the tumors. In summary, combined treatment with budesonide and R115777 produced the following results: (i) it was more efficacious in preventing lung tumors than the individual drugs; and (ii) it prevented and reversed DNA hypomethylation in lung tumors. These results support the combined use of budesonide and R115777 in prevention of lung tumors and suggest that reversal of DNA hypomethylation in lung tumors would be useful as a surrogate end-point biomarker for prevention.
Carcinogenesis 2007 Jan
PMID:Prevention of mouse lung tumors and modulation of DNA methylation by combined treatment with budesonide and R115777 (Zarnestra MT). 1798 18

CpG endonuclease activity was identified in nuclear extracts obtained from mouse lung tumors. Enzyme activity was determined using a 333 bp polymerase chain reaction product of the estrogen receptor-alpha gene that contained either radiolabeled cytosine or tritium-labeled methyl groups at CpG sites. Activity was measured as the release of radioactivity from the substrate. The product of the nuclease activity was identified by high pressure liquid chromatography (HPLC) as either 5-methyl-2'-deoxycytidine when the CpG sites in the substrate were methylated or 2'-deoxycytidine when the CpG sites were not methylated. The CpG endonuclease activity was dependent on nuclear protein and temperature, had a proclivity for double-stranded over single-stranded DNA and was inhibited by ethylenediaminetetraacetic acid or 2-mercaptoethanol. Strain A/J mouse lung tumors induced by vinyl carbamate had a greater level of CpG endonuclease activity than non-involved lung tissue. Budesonide, a potent chemopreventive agent in mouse lung, not only prevented an increase in CpG endonuclease activity in lung tumors but, when administered to mice with established tumors, also decreased the level of endonuclease activity in the tumors. The effect of budesonide on CpG endonuclease activity in lung tumors was inversely related to its published effect on DNA methylation in mouse lung tumors, i.e. the drug decreased CpG endonuclease activity and increased the methylation of DNA. The increased CpG endonuclease activity in mouse lung tumors and its inhibition by budesonide would suggest this endonuclease as a potential molecular target for chemoprevention.
Carcinogenesis 2007 Jul
PMID:Modulation by budesonide of a CpG endonuclease in mouse lung tumors. 1736 Oct 11