nutlin-1 and Pterygium

Nutlin is a drug that has been reported to activate p53 in various cell lines. We aim to study the effects of Nutlin in pterygium and compare the effects of Nutlin and mitomycin C (MMC) in pterygium cell lines.. Pterygium samples (n = 3) were collected during surgical excision. Normal conjunctival tissues (n = 3) were collected from another quadrant of the same eye. Cell lines were established, and cells from passages 2 to 5 were used. Pterygium and conjunctival cells were treated with different doses of Nutlin and MMC. Cell proliferation and cell migration were measured.. Cell proliferation was reduced by 39-fold after treatment with 50 μM Nutlin. Cell migration was inhibited with increasing dosages of Nutlin (95% and 28% after treating with 2 and 50 μM Nutlin, respectively). Compared with MMC, Nutlin induced more pterygium cell death and less conjunctival cell death at low doses. At 50% lethal dose for pterygium cells, 95% of conjunctival cells survived after Nutlin treatment, whereas only 63% of conjunctival cells survived after MMC treatment. p21 expression was not detectable in MMC-treated pterygium cells but was detectable after Nutlin treatment.. In our study, MMC induced cell death in pterygium and conjunctival cell lines, whereas Nutlin had a targeted impact on pterygium cells. Our results implied that MMC inhibited both pterygium cell proliferation and migration through an apoptosis-independent pathway.

Topics: Analysis of Variance; Apoptosis; Cell Line; Cell Movement; Cell Proliferation; Conjunctiva; Cyclin-Dependent Kinase Inhibitor p21; Humans; Imidazoles; Mitomycin; Piperazines; Proto-Oncogene Proteins c-mdm2; Pterygium

To confirm that mouse double minute 2 (MDM2) could inhibit p53 activity in human pterygium. And to show the disruption of MDM2-p53 interaction could reactive the functions of p53 in pterygium.. Pterygium and corresponding conjunctiva tissues were collected for establishment of primary cell lines. Expression patterns of MDM2 and p53 were detected by immunofluorescence. Protein localization of p53 and MDM2, and transcriptional activity of p53 in both untreated and MDM2 antagonist (Nutlin) treated pterygium cells were quantified.. In pterygium, p53 was highly expressed in cytoplasm and slightly expressed in the nuclei. MDM2 was localized in the nuclei. A p53 transcriptional regulated target gene, p21, was not expressed in pterygium tissues, suggesting the p53 transcriptional activity was not active in pterygium. After treatment with Nutlin, increased nuclear localization of p53 (4.05%-80.56%) was observed in pterygium cells along with increasing Nutlin dosages (from 0 to 50 μM, p < 0.001). The expression of p21 was increased after Nutlin treatments in pterygium cells (2.49 folds in 20 μM Nutlin treated cells compared to control treated cells, p = 0.012).. We discovered a novel mechanism in pterygium whereby MDM2 suppresses p53 transcriptional activity despite abundant p53 in pterygium. Disruption of MDM2-p53 interaction by Nutlin could be a potential treatment for pterygium.

Topics: Adult; Aged; Aged, 80 and over; Cell Line; Conjunctiva; Female; Fluorescent Antibody Technique, Indirect; Humans; Imidazoles; Immunoblotting; Male; Middle Aged; Piperazines; Proto-Oncogene Proteins c-mdm2; Pterygium; Tumor Suppressor Protein p53