The role of Indoleamine 2,3 Dioxygenase in Acute Myeloid Leukemia

IDO has a role in immunosuppressive and tolerogenic mechanism in many solid tumor cells. Upregulation of IDO in acute myeloid leukemia has been recently reported. This book presents our research work which assessed both the IDO RNA expression & its enzymatic activity in the blast cells of AML patients. It also assessed the effect of pharmacological IDO inhibitor (1MT) on culture leukemia blast cells in relation to the effect of most traditionally used chemotherapeutic agent: adriamycin. The study included 25 AML patients & 25 healthy volunteers. All underwent assessment of IDO enzymatic activity & IDO RNA estimation by RT-PCR in peripheral blood MNCs. Also the MNCs were cultured to test the effect 1MT alone, and in combination with adriamycin on cell proliferation and IDO expression. The study revealed significant difference of IDO RNA expression & activity among the two groups (p > 0.01). Also there was a significant inhibition of proliferation of blast cells under the effect of both IDO inhibitor & adriamycin (p > 0.01). We concluded that, the role of IDO in tumor induced immune tolerance was confirmed and the benefits effect of IDO inhibitor in enhancing the anticancer effect