Journal: PLoS ONE
Article Title: A small molecule drug promoting miRNA processing induces alternative splicing of MdmX transcript and rescues p53 activity in human cancer cells overexpressing MdmX protein
doi: 10.1371/journal.pone.0185801
Figure Lengend Snippet: ( A, left ) A375 cells stably transfected with a p53-responsive luciferase reporter construct were grown for 24 hours in the presence of enoxacin in concentrations 25, 50, 75, and 100 μg/ml. Relative p53 transcriptional activity was determined by measuring the activity of luciferase in cell lysates. Results of three independent experiments are presented (means + SD). * P<0.05, ** P<0.01 (Student’s t-test, two-tailed). ( A, right ) A375 cells were treated with enoxacin for 24 hours, lysed, and protein levels of MdmX and p53 in cell lysates were analyzed by Western blotting. PCNA served as a loading control. ( B ) A375 cells stably transfected with a p53 activity reporter construct were treated with 0.2% NaOH (control), etoposide, and three fluoroquinolone antibiotics, and p53 activity was determined. Results of three independent experiments (means + SD) are presented. A significant difference between control and antibiotic-treated cells * P<0.05, ** P<0.01 (Student’s t-test, two-tailed). ( C ) Quantitative real-time PCR analysis of the expression of selected p53 target genes in A375 cells treated for 24 hours with 50 or 100 μg/ml enoxacin or 0.5 μM doxorubicin. The expression of HPRT1/HGPRT served as an endogenous control. ( D ) Mel-Juso cells stably transfected with a p53-responsive luciferase reporter construct were grown for 24 hours in the presence of enoxacin in concentrations 50 and 100 μg/ml. Relative p53 activity was determined by measuring luciferase activity in cell lysates. Results of three independent experiments are presented (means + SD). * P<0.05, (Student’s t-test, two-tailed). MdmX and p53 protein levels in Mel-Juso cell lysates were analyzed by Western blotting. PCNA served as a loading control. ( E ) ( F ) Western blot analysis of A375 cells treated with increasing concentrations of enoxacin or DNA damaging drugs for the indicated time. A mixture of three different primary monoclonal antibodies recognizing various epitopes in human Mdm2 was used in the Mdm2 panels. * Non-specific band.
Article Snippet: The human cancer cell lines A375, Mel-Juso, Mel-Ho, IPC298, H1299, A2780, and MCF7 (obtained from ECACC, DSMZ, and ATCC) were cultured at 37°C and 5% CO 2 in RPMI-1640 medium (Sigma-Aldrich), supplemented with 10% fetal bovine serum, 2mM L-glutamine, 100 IU/mL penicillin and 100 μg/mL streptomycin.
Techniques: Stable Transfection, Transfection, Luciferase, Construct, Activity Assay, Two Tailed Test, Western Blot, Control, Real-time Polymerase Chain Reaction, Expressing, Bioprocessing