The role of histone H3 phosphorylation at Ser10 in regulating proliferation and transformation of human nasopharyngeal carcinoma cells / 肿瘤

ABSTRACT

Objective: To explore the role of histone H3 phosphorylation at serine10 (Ser10) in regulating proliferation and transformation of human nasopharyngeal carcinoma cell line CNE1. Methods: The level of histone H3 phosphorylation at Ser10 was detected by Western blotting in the presence of epidermal growth factor (EGF). The wide-type histone H3 (H3WT) and mutant histone H3 (H3S10A) recombinant expression vectors were constructed, and then were transfected into CNE1 cells. The CNE1 cells stably expressing wide-type and mutant histone H3 were screened with blasticidin, and then the expression of histone H3 and EGF-induced histone H3 phosphorylation at Ser10 were detected in transfected cells by Western blotting. Cell counting kit-8 (CCK-8) assay and soft agar assay were employed to assess the effect of over-expression of wide-type and mutant histone H3 on proliferation and colony-formation of CNE1 cells. The expression levels of c-Jun, c-Fos and Bcl-2 were detected by Western blotting, and the activator protein-1 (AP-1) transcriptional activation were examined by dual-luciferase reporter gene assay. Results: EGF induced phosphorylation of histone H3 at Ser10 in CNE1 cells. The CNE1 cells stably overexpressing histone H3WT and mutant H3S10A were successfully established. The level of histone H3 phosphorylation at Ser10 induced by EGF was greatly decreased in mutant H3S10A CNE1 cells. As compared with the mock control tranfected with an empty vector, the abilities of proliferation and colony formation were obviously promoted in H3WT-overexpressing CNE1 cells stimulated by EGF, as well as the expression levels of c-Jun and c-Fos and transcriptional activation of AP-1 were significantly increased. However, no significant changes were observed in mutant H3S10A-overexpressing CNE1 cells. Conclusion: Histone H3, especially the Ser10 motif, might have an important role in regulating EGF-induced proliferation and transformation of CNE1 cells, which is relate with promoting c-Jun and c-Fos gene transcription and thereby enhancing AP-1 activity.