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1.
Biol. Res ; 49: 1-16, 2016. ilus, graf
Article Dans Anglais | LILACS | ID: biblio-950861

Résumé

BACKGROUND: Cellular senescence is induced either internally, for example by replication exhaustion and cell division, or externally, for example by irradiation. In both cases, cellular damages accumulate which, if not successfully repaired, can result in senescence induction. Recently, we determined the transcriptional changes combined with the transition into replicative senescence in primary human fibroblast strains. Here, by γ-irradiation we induced premature cellular senescence in the fibroblast cell strains (HFF and MRC-5) and determined the corresponding transcriptional changes by high-throughput RNA sequencing. RESULTS: Comparing the transcriptomes, we found a high degree of similarity in differential gene expression in replicative as well as in irradiation induced senescence for both cell strains suggesting, in each cell strain, a common cellular response to error accumulation. On the functional pathway level, "Cell cycle" was the only pathway commonly down-regulated in replicative and irradiation-induced senescence in both fibroblast strains, confirming the tight link between DNA repair and cell cycle regulation. However, "DNA repair" and "replication" pathways were down-regulated more strongly in fibroblasts undergoing replicative exhaustion. We also retrieved genes and pathways in each of the cell strains specific for irradiation induced senescence. CONCLUSION: We found the pathways associated with "DNA repair" and "replication" less stringently regulated in irradiation induced compared to replicative senescence. The strong regulation of these pathways in replicative senescence highlights the importance of replication errors for its induction.


Sujets)
Humains , Mâle , Vieillissement de la cellule/physiologie , Fibroblastes/effets des radiations , Facteurs temps , Altération de l'ADN , Immunotransfert , Régulation négative/effets des radiations , Régulation positive/effets des radiations , Cellules cultivées , Analyse de variance , Vieillissement de la cellule/effets des radiations , Vieillissement de la cellule/génétique , beta-Galactosidase/métabolisme , Analyse de séquence d'ARN , Analyse de profil d'expression de gènes , Foetus avorté , Réparation de l'ADN/effets des radiations , Réplication de l'ADN/effets des radiations , Fibroblastes/physiologie , Rayons gamma , Poumon
2.
Journal of Veterinary Science ; : 207-214, 2013.
Article Dans Anglais | WPRIM | ID: wpr-104697

Résumé

To evaluate radiosensitivity and the effects of radiation on the expression of vascular endothelial growth factor (VEGF) and VEGF receptors in the canine oral melanoma cell line, TLM 1, cells were irradiated with doses of 0, 2, 4, 6, 8 and 10 Gray (Gy). Survival rates were then determined by a MTT assay, while vascular endothelial growth factor receptor (VEGFR)-1 and -2 expression was measured by flow cytometry and apoptotic cell death rates were investigated using an Annexin assay. Additionally, a commercially available canine VEGF ELISA kit was used to measure VEGF. Radiosensitivity was detected in TLM 1 cells, and mitotic and apoptotic cell death was found to occur in a radiation dose dependent manner. VEGF was secreted constitutively and significant up-regulation was observed in the 8 and 10 Gy irradiated cells. In addition, a minor portion of TLM 1 cells expressed vascular endothelial growth factor receptor (VEGFR)-1 intracellularly. VEGFR-2 was detected in the cytoplasm and was down-regulated following radiation with increasing dosages. In TLM 1 cells, apoptosis plays an important role in radiation induced cell death. It has also been suggested that the significantly higher VEGF production in the 8 and 10 Gy group could lead to tumour resistance.


Sujets)
Animaux , Chiens , Apoptose/effets des radiations , Lignée cellulaire tumorale/effets des radiations , Relation dose-effet des rayonnements , Test ELISA/médecine vétérinaire , Mélanome/génétique , Tumeurs de la bouche/génétique , Radiotolérance , Sels de tétrazolium/métabolisme , Thiazoles/métabolisme , Régulation positive/effets des radiations , Facteur de croissance endothéliale vasculaire de type A/génétique , Récepteur-1 au facteur croissance endothéliale vasculaire/génétique , Récepteur-2 au facteur croissance endothéliale vasculaire/génétique
3.
Journal of Korean Medical Science ; : 879-886, 2004.
Article Dans Anglais | WPRIM | ID: wpr-175769

Résumé

The expression of vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF)2 in the irradiated brain was examined to test how a single high dose radiation, similar to that used for intraoperative radiation therapy given to the normal cerebrum, can affect the vascular endothelium. After a burr hole trephination in the rat skull, the cerebral hemisphere was exposed to a single 10 Gy dose of gamma rays, and the radiation effect was assessed at 1, 2, 4, 6, and 8 weeks after irradiation. His-tological changes, such as reactive gliosis, inflammation, vascular proliferation and necrosis, were correlated with the duration after irradiation. Significant VEGF and FGF2 expression in the 2- and 8-week were detected by enzyme-linked immunosorbent assay quantification in the radiation group. Immunohistochemical study for VEGF was done and the number of positive cells gradually increased over time, compared with the sham operation group. In conclusion, the radiation injuries consisted of radiation necrosis associated with the expression of VEGF and FGF2. These findings indicate that VEGF and FGF2 may play a role in the radiation injuries after intraoperative single high-dose irradiation.


Sujets)
Animaux , Rats , Encéphale/métabolisme , Lésions encéphaliques/étiologie , Facteur de croissance fibroblastique de type 2/métabolisme , Nécrose , Lésions radiques/anatomopathologie , Radiochirurgie/effets indésirables , Rat Sprague-Dawley , Régulation positive/effets des radiations , Facteur de croissance endothéliale vasculaire de type A/métabolisme
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