Authors : Haixiao Zhou, Zhigang Liu, Linying Huang, Anhuai Yang, Junping Li and Zhen Chen
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 μg mL-1 as confirmed by RT-PCR, real-time PCR and flow cytometry assays (p<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<0.01). B7-H1 siRNA significantly silenced B7-H1 expression in Y79 cells as confirmed by RT-PCR and Western blotting assays (p<0.01).
Haixiao Zhou, Zhigang Liu, Linying Huang, Anhuai Yang, Junping Li and Zhen Chen, 2013. ERK MAP-Kinase is Involved in the B7-H1 Expression Induced by Etoposide In Retinoblastoma Cells. Journal of Animal and Veterinary Advances, 12: 369-376.