[Expression of HIF-1α in primary acute myeloid leukemia cells and its relationship with prognosis].

OBJECTIVE: This study was aimed to detect the expression of HIF-1α in acute myeloid leukemia (AML) except acute promyelocyte leukemia (APL) and investigate the relationship of its expression levels with clinical parameters and prognosis. METHODS: The primary AML cells were collected from peripheral blood of 53 newly diagnosed AML patients by using CD3 negative sorting. The expression of HIF-1α was measured by real-time fluorescent quantitative PCR (FQ-PCR) , and the relationship between expression level of HIF-1α and clinical parameters (age, sex, WBC count, clinical typing, prognosis) was analysed according to relative expression level. Furthermore, Western blot was used to detect the protein level of HIF-1α in AML patients with or without extramedullary infiltration. RESULTS: The expression level of HIF-1α did not correlate with age, sex, WBC count, Hb level, Plt count and the percentage of blast. There was no significant difference of HIF-1α expression between different AML subtype based on FAB. The higher level of HIF-1α was found in AML patients who did not get complete remission after one or two courses of chemotherapy, however, the difference was not statistically significant. The relapse rate was higher in AML patients with the higher expression of HIF-1α. In addition, the higher level of HIF-1α mRNA and protein were found in bone marrow of AML patients with extramedullary infiltration (P < 0.01). The negative correlation between HIF-1α and PTEN was observed (r = -0.48, P = 0.001). CONCLUSIONS: Overexpression of HIF-1α are closely related with extramedullary infiltration and prognosis of acute myeloid leukemia, and may be used as an early indicator of extramedullary infiltration and prognosis.

The effect to IL-3Ralpha, downstream PI3k/Akt signaling of all-trans retinoic acid and arsenic trioxide in NB4 cells.

All-trans retinoic acid (ATRA) and arsenic trioxide (As2O3) are the classic drugs used for induction therapy of acute promyelocytic leukemia (APL). IL-3Ralpha (CD123) is a specific marker of acute myeloid leukemia stem cells (AML-LSCs). The over-expression of IL-3Ralpha in patients with AML is related to high white blood cells counts, high percentages of blast cells, and poor prognosis. Moreover, in some studies, IL-3Ralpha has been considered a new detection marker of minimal residual disease in the bone marrow from patients with APL. In contrast to ATRA, As2O3 reduces both mRNA and protein expression of IL-3Ralpha and inhibits the activity of PI3K/Akt after 24 h, 48 h, and 72 h of exposure. Furthermore, NB4 cells adhered to the human stroma cell line HS-5 cells were used as an in vitro model of APL cells in the bone marrow microenvironment. Our results demonstrate that adhesion to HS-5 cells up-regulated IL-3Ralpha protein expression and activated the downstream PI3K/Akt signaling pathway in NB4 cells. Compared with ATRA, As2O3 more potently inhibits proliferation of NB4 cells adhered to stroma cells.