T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive neoplastic disorder of immature hematopoietic precursors committed to T-cell lineage. T-ALL accounts for ~15% of pediatric ALL cases and is prone to early relapse. With new and improved treatment protocols, the prognosis

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive neoplastic disorder of immature hematopoietic precursors committed to T-cell lineage. T-ALL accounts for ~15% of pediatric ALL cases and is prone to early relapse. With new and improved treatment protocols, the prognosis of T-ALL has improved particularly in children; however, the outcome of relapsed T-ALL cases remains poor. The AIOLOS gene is necessary to control lymphocyte differentiation and may be a potential target of T-ALL therapy. In the present study, Jurkat cells were divided into three groups: untransfected (UT) control, lentiviral vector control (LentiMock) and AIOLOS-overexpressing (Lenti-AIOLOS) groups. Lenti-AIOLOS Jurkat cells were constructed by lentiviral transduction; cell cycle analysis, apoptosis and cytotoxicity assays were then performed to evaluate the effects of AIOLOS on cell cycle distribution, apoptosis and cell chemosensitivity to etoposide of Jurkat cells in vitro. Moreover, the expression levels of genes associated with apoptosis and cell cycle were investigated by quantitative reverse transcription-polymerase chain reaction. Results showed that the percentage of Jurkat cells in the G0/G1 phase increased from 71.5 (UT) to 85.4% (Lenti-AIOLOS; P<0.05), yet the percentage of cells in the S-phase decreased from 15.1 (UT) to 11.6% (Lenti-AIOLOS; P<0.05). The percentage of total apoptotic cells was significantly increased in the AIOLOS-transfected Jurkat cells (21.93%) compared with this percentage in the Lenti-Mock (13.35%) or the UT group (13.30%; P<0.05). Consistent with these results, AIOLOS overexpression induced P21 and P27 upregulation and CCND3 and SKP2 downregulation. Furthermore, AIOLOS overexpression synergistically increased the cytotoxic effects of etoposide and downregulated NF-κB expression. Our findings revealed that lentivirusmediated AIOLOS overexpression in Jurkat cells induced cell apoptosis, arrested the cell cycle at the G0/G1 phase, and synergistically increased the sensitivity of Jurkat cells to etoposide by inhibiting NF-κB activity.