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Miranda Michele Zarivi Osvaldo Amicarelli Fernanda Ragnelli Anna Maria Aimola Pierpaolo Porretta Rocchina Natali Pier Giorgio Arcadi Antonio Savino Maria Poma Anna Bonfigli Antonella 《Journal of neuro-oncology》1997,31(1-2):185-193
This paper presents evidence that L-tyrosine oxidation products and 5,6-dihydroxyindole, an intermediate of melanin synthesis bind to and modify DNA structure, as tested by extracting cell DNA, using topoisomerase I and denaturation assays. When supercoiled plasmid pCU18 or pBR322 DNAs are treated with 5,6-dihydroxyindole the supercoiled species disappear and are converted to species less mobile in a gel retardation test with respect to relaxed DNA. 5,6-Dihydroxyindole causes an easier acid denaturation of the double helix. The results, that are dose dependent,would point to both intercalation and cross-linking of DNA by 5,6-dihydroxyindole and its oxidation product(s). 3H-L-tyrosine deriving radioactivity, bound to nuclear DNA, is higher at low pH, (5.6) if compared to pH 6.8. The highest radioactivity bound to cell DNA is found during the transition from the amelanotic to the melanotic phenotype in human melanoma cell lines. As a control, the binding of 3H-L-tyrosine radioactivity to human prostate fibroblast DNA was investigated. 相似文献
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Amicarelli F; Bucciarelli T; Poma A; Aimola P; Di Ilio C; Ragnelli AM; Miranda M 《Carcinogenesis》1998,19(3):519-523
The effects of methylglyoxal on the growth of a line of human melanoma
cells are investigated. Methylglyoxal inhibits cell growth in a dose-
dependent manner and causes an increase in glyceraldehyde 3-phosphate
dehydrogenase, and glyoxalase 1 and glyoxalase 2 specific activities. The
cellular response to increasing concentrations of methylglyoxal in the
culture medium is also studied by measuring L-lactate production,
reduced-oxidized glutathione levels and apoptotic cell death. Methylglyoxal
seems to promote a change of cell population phenotypic repertoire toward a
more monomorphic phenotype. In conclusion, methylglyoxal seems to induce an
enzymatic cellular response that lowers methylglyoxal levels and selects
the most resistant cells.
相似文献
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M Miranda G Bartoli A M Ragnelli A Cittadini P Palozza P Aimola O Zarivi A Bonfigli 《Journal of submicroscopic cytology and pathology》1992,24(2):273-279
The effects of a low copper diet on pigmentation, pigment cell and melanosome morphology have been investigated in ACI/T male rats. After a three months treatment the fur and skin pigmentation is reduced as compared to the controls. The melanocytes of the treated rats show the phenotype of active pigment cells while some melanosomes are abnormally differentiated: both lamellar and granular organelles are present in the same pigment cell and mosaic age melanosomes appear. The abnormal melanosome structure expressed by the treated-rat melanocytes is also evident in vitro. After incubation with deoxycholate the melanosomes from the low-copper diet treated rats are much more altered than those from the control rats. The phenotype of the rats starved for copper seems to mimic as regards pigmentation the phenotype of the mouse Mo (mottled) mutation that is an experimental model of the Menkes' kinky hair syndrome. In conclusion copper deficiency seems to affect both the morphology and function of the pigment cells. 相似文献
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Tatone C Carbone MC Falone S Aimola P Giardinelli A Caserta D Marci R Pandolfi A Ragnelli AM Amicarelli F 《Molecular human reproduction》2006,12(11):655-660
Limited knowledge exists about changes in follicle quality associated with age. The aim of this work was to investigate whether ageing may cause oxidative stress-mediated alterations in human granulosa cells (GCs) from periovulatory follicles. GCs employed in this study were obtained from follicular aspirates of 20 younger women (range 27-32 years) and 20 older women (range 38-41 years) undergoing an IVF treatment. Results obtained from comparative RT-PCR analysis revealed that the mean relative levels of mRNAs coding for superoxide dismutases, Cu, ZnSOD (SOD1), MnSOD (SOD2) and catalase were significantly decreased in women > or =38 years (P < 0.05, Student's t-test). These changes were associated with a reduced expression of SOD1, SOD2 and catalase at the protein level. When examined at an ultrastructural level, most of the GCs from this group showed defective mitochondria and fewer lipid droplets than those observed in the younger group. These results indicate that GCs from older patients suffer from age-dependent oxidative stress injury and are taken as an evidence for reduced defence against reactive oxygen species (ROS) in GCs during reproductive ageing. 相似文献
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