Abstract: Objective To observe the effects of decitabine on the proliferation, apoptosis and hormone secretion of adrenocorticotropic hormone (ACTH) pituitary adenoma AtT-20 cells. Methods The drug groups were given different concentrations of decitabine(1, 5, 10 μM), and control group was given equal volume of dimethyl sulfoxide (DMSO). The proliferation of AtT-20 cells was determined by MTS test after treated with different concentrations of decitabine for 24, 48, 72 h, and the apoptosis levels were measured by Annexin V/PI. Simultaneously, ACTH secretion ofAtT-20 cells by ELISA and the mRNA expression of apoptosis related genes such as Bax and Bcl-2 by Real-time PCR were detected. Results Compared with control group, decitabine could effectively inhibit the proliferation and ACTH secretion of AtT-20 cells in a concentration-dependent and time-dependent manner. After 72 h treatment, the apoptosis cells in decitabine groups were significantly increased. And the levels of Bax were increased and expressions of Bcl-2 mRNA were statistically decreased in decitabine groups than that of control group (P <0.05). Conclusion Decitabine can induce apoptosis of AtT-20 cells and inhibit cell proliferation and ACTH secretion. Decitabine might have a potential protective effect on pituitary-dependent Cushing's disease.

Key words: decitabine, pituitary-dependent Cushing's disease, ACTH, AtT-20 cells, proliferation