Transferred Tumor suppressor BLU inhibits proliferation of nasopharyngeal carcinoma cells by regulation of cell cycle, JNK and cyclin D1 promoters

Background: Tumor suppressor genes are often engaged in signaling pathways to regulate proliferation so as to block growth of tumor cells. To explore the mechanism underlying the tumor suppression activity of BLU/ZMYND10 gene on a frequently lost human chromosomal region, adenoviral vector with BLU cDNA insert was constructed. Methods: BLU gene was re-expressed in nasopharyngeal carcinoma cells by transfection or viral infection. Clonogenic growth was assayed; cell cycle was analyzed by flow cytometry-based DNA content detection; JNK and cyclin D1 promoter activities were measured by reporter gene assay, and phosphorylation was measured by immunoblotting. The data of each pair of groups were compared with Student t test. Results: BLU inhibits clonogenic growth of nasopharyngeal carcinoma cells, arrests cell cycle at G1 phase, downregulates JNK and cyclin D1 promoter activities, and inhbits phosphorylation of c-Jun molecule. Conclusion: BLU inhibits growth of nasopharyngeal carcinoma cells by regulation of JNK-cyclin D1 axis to exert tumor suppression.