Identification of a novel large deletion of factor subunit A mRNA associated with hereditary factor deficiency / 中华血液学杂志

<p><b>OBJECTIVE</b>To analyze the expressed mRNA of the factor subunit A (FA) in monocyte in a hereditary factor (F) deficiency family.</p><p><b>METHODS</b>The F A mRNA of the proband and the other family members was analyzed by RT-PCR, semi-quantitative RT-PCR, cloning and sequencing. The three dimensional structure of the protein was predicted by SWISS-MODEL and viewed by RASMIOL.</p><p><b>RESULTS</b>(1) A large in frame deletion from codons 11 to 279, spanning from exon 2 to 7 of F A (DelCD11-279), was identified in the proband at mRNA level and a truncated protein is predicted composed of 464 amino acids. Compared with the normal and the other families, the proband showed lower level of F A mRNA in RT-PCR. (2) SWISS-MODEL analysis showed that the truncated protein lacked the β-sandwich and a part of catalytic core, resulting in loss of the normal catalytic domains.</p><p><b>CONCLUSION</b>DelCD11-279 of F A mRNA is associated with hereditary F deficiency. The reduced expressing level of F A gene is one of the causes resulting in F deficiency in the patients.</p>

ITF-2357 on inhibition myeloid leukemic cell lines cells proliferation in vitro and its mechanism / 中华血液学杂志

<p><b>OBJECTIVE</b>To explore the effect of ITF2357, a novel histone deacetylase (HDAC) inhibitor, on the growth, differentiation and apoptosis of acute myeloid leukemic (AML) cells and its mechanism.</p><p><b>METHODS</b>AML cell lines kasumi-1 cells as a model for AML1-ETO positive, and THP1 cells for AML1-ETO negative, the leukemic cells proliferation was analyzed by MTT assay, expression of myeloid-specific differentiation antigen and cell cycle by flow cytometry, cell apoptosis by annexin V staining and flow cytometry. AML1-ETO, acetyl-histone, and caspase protein was analyzed by Western blot.</p><p><b>RESULTS</b>0.5 µmol/L ITF2357 treatment significantly inhibited kasumi-1 cells proliferation, with the 48 h half inhibitory concentration (IC(50)) of 0.1 µmol/L. The initial inhibitory concentration of THP1 cell line was 5 µmol/L. ITF 2357 induced apoptosis of kasumi-1 cells in a time- and dose-dependent manner. A dose-dependent increase in early apoptosis occurred at 24 hours treatment and in late apoptosis at 48 hours treatment by ITF2357. Early apoptosis cells increased from (1.44 ± 1.52)% to (24.51 ± 5.79)%. Late apoptosis cells increased from (2.37 ± 2.8)% to (63.66 ± 1.56)%. ITF2357 induced AML1-ETO degradation by caspase-dependent pathway. 0.25 µmol/L ITF2357 induced a time- and dose-dependent increase in expression of myeloid cell surface protein CD13 and CD15. 5 µmol/L ITF2357 blocked the cells at G(0)/G(1) phase, G(0)/G(1) cells increased from (39.69 ± 6.56)% to (79.2 ± 6.51)% and s-phase cells declined from (60.12 ± 3.29)% to (18.97 ± 6.62)%. Kasumi-1 cells incubated with 0.5 µmol/L of ITF2357, AML1-ETO protein began to decrease at 24 hours and could hardly be detected at 96 hours. ITF2357 induced AML1/ETO degradation through a caspase-dependent mechanism. At the same time, acetylated H3 and H4 increased.</p><p><b>CONCLUSION</b>Low-dose HDAC inhibitor ITF2357 can effectively inhibit the AML cells proliferation, especially for AML1-ETO positive AML cells. It inhibits Kasumi-1 cells proliferation degradation of AML1-ETO protein expression, blocks the cells at G(0)/G(1) phase, and induces apoptosis and differentiation of the cells.</p>