Background
Acute myelogenous leukemia (AML) is a cancer of the blood that most commonly affects human adults. The specific cause of AML is unclear, but it induces abnormality of white blood cells that grow rapidly and accumulate in bone marrow interfering with the production and functions of the normal blood cells. AML patients face poor prognosis and low quality of life during chemotherapy or transplantation of hematopoietic stem cells due to the progressive impairment of their immune system. The goal of this study is to find natural products that have the potential to delay growth or eliminate the abnormal leukemic cells but cause less harmful effect to the body's immune system.
Conclusions
Rice bran gramisterol possesses a promising anti-cancer effect against a tumor of white blood cells and induces the production of anti-cancer immune-related cytokines. Gramisterol induces cell cycle arrest and apoptosis via suppression of pSTAT3 signaling control of tumor cells' growth and progression. Gramisterol increased IFN-γ production and prevented the dysfunctional immune system of leukemic mice by enhancing pSTAT1 transcription signal controlling proliferation and functions of hematopoietic cells in the spleen. Together with IFN-γ, gramisterol efficiently facilitates leukemic mice immune system modulation leading to improvement of the AML condition. Administration of RBDS containing gramisterol potentiates immune recovery of leukemic mice and extends their survival. This finding encourages the medicinal application of rice bran gramisterol as a palliative treatment or an alternative agent for future drug development against AML.