Low-dose arsenic trioxide enhances membrane-GLUT1 expression and glucose uptake via AKT activation to support L-02 cell aberrant proliferation

Long term low dose exposure of arsenic has been reported to lead various cells proliferation and malignant transformation. GLUT1, as the key transporter of glucose, has been reported to have association with rapid proliferation of various cells or tumor cells. In our study, we found that low dose exposure to arsenic trioxide (0.1μmol/L As₂O₃) could induce an increase in glucose uptake and promote cell viability and DNA synthesis. And, 2-DG, a non-metabolized glucose analog, significantly decreased the glucose uptake and cell proliferation of 0.1μmol/L As₂O₃ treated L-02 cells. However, 4 mmol/L 2-DG was co-utilized with equal dose glucose had no significant effect on the cell proliferation of 0.1μmol/L As₂O₃ treated L-02 cells. Further studies showed that exposure to 0.1μmol/L As₂O₃ could promote the expression of GLUT1 on plasma membrane. Inhibition of GLUT1 expression by 5μmol/L BAY-876 significantly decreased the abilities of glucose uptake and cell proliferation in As₂O₃-treated L-02 cells. Moreover, 0.1μmol/L As₂O₃ induced the Akt activation indicated by increased the phospho-AKT (Ser473 and Thr308). Knockdown Akt by shRNA or inhibited Akt activation by LY294002 was followed by significantly decreased glucose uptake, GLUT1 plasma membrane expression and cell proliferation in As₂O₃-treated L-02 cells. All in all, these results demonstrated that arsenic trioxide-induced Akt activation contributed to the cells proliferation through upregulating expression of GLUT1 on plasma membrane that enhanced glucose uptake.