Zhen  Chen, Junping  Li, Anhuai  Yang, Linying  Huang, Zhigang  Liu, Haixiao  Zhou, 
    ERK MAP-Kinase is Involved in the B7-H1 Expression Induced by Etoposide In Retinoblastoma Cells,
    Journal of Animal and Veterinary Advances,
    Volume 12,Issue 3,
    2013,
    Pages 369-376,
    ISSN 1680-5593,
    javaa.2013.369.376,
    (https://makhillpublications.co/view-article.php?doi=javaa.2013.369.376)
    Abstract: The effect of etoposide on B7-H1 expression was determined by the Reverse-Transcription Polymerase Chain Re-action (RT-PCR), real-time PCR and flow cytometry analysis in Y79 cells. Then, the involvement of Mitogen-Activated Protein Kinases (MAPKs) signal pathways were tested by Western blotting and signal transduction inhibitor assays. Furthmore, specific small interfering RNA (siRNA) targeting B7-H1 was transfected into Y79 retinoblastoma cells using liposome. Silencing of B7-H1 expression was measured by RT-PCR and Western blotting assays. Etoposide increased B7-H1 mRNA and protein levels in Y79 cells. The effect of etoposide on B7-H1 expression peaked at the concentration of 5 &#956;g mL<SUP>-1</SUP> as confirmed by RT-PCR, real-time PCR and flow cytometry assays (p&lt;0.01). The phosphorylation status of Extracellular Signal-Regulated Kinase (ERK), c-Jun N-terminal Kinase (JNK) were constitutively activated by etoposide and MEK inhibitor simultaneously reduced the expression of B7-H1 induced by etoposide (p&lt;0.01). B7-H1 siRNA significantly silenced B7-H1 expression in Y79 cells as confirmed by RT-PCR and Western blotting assays (p&lt;0.01).
    Keywords: mitogen-activated protein kinases;etoposide;B7-H1;Retinoblastoma;small interfering RNA