Background & objective: NPC-associated gene NAG7 was a novel candidate tumor suppressor gene associated with nasopharyngeal carcinoma cloned in our laboratory. This study was designed to investigate the potential effect of NAG7 on the cell cycle and apoptosis of nasopharyngeal carcinoma cell line HNE1 and its molecular mechanism.
Methods: NAG7 gene was introduced into HNE1 cells using lipofectin transfection technique. The expression level of NAG7 gene was analyzed by Northern blot. Cell cycle, cyclins, and cell apoptosis were detected by flow cytometry, and the expressions of cyclin D1 and cyclin E were detected by Western blot.
Results: NAG7 gene was re-expressed in NAG7 transfected HNE1 cells. Compared with HNE1 cells and vector transfected HNE1 cells, NAG7 transfected HNE1 cells arrested in G0/G1 phase increased (P < 0.05) and cells in S phase decreased (P < 0.05), the apoptosis cells increased (P < 0.05), and the levels of cyclins of A, B1, D1, and E decreased. Furthermore, the expression of cyclin D1 and E decreased in NAG7 transfected HNE1 cells.
Conclusion: NAG7 gene re-expression could inhibit overproliferation of NPC cell by delaying the progression of G1 into S in cell cycle and inducing cell apoptosis.