The Effect of MicroRNA-143 on the Proliferation and Apoptosis of Leukemia Cell Line U-937 / 中国实验血液学杂志

OBJECTIVE@#To investigate the expression of microRNA-143 (miR-143) in patients with acute myeloid leukemia (AML), and the effect of miR-143 over-expression on the proliferation and apoptosis of AML cells. And to verify the targeting relationship between miR-143 and long non-coding RNA MALAT-1. So as to explore the possible regulatory mechanism of miR-143 in the pathogenesis of AML.@*METHODS@#The expression of miR-143 in bone marrow cells of AML patients was detected by RT-qPCR. After miR-143 was over-expressed in U-937 cell lines, the proliferation of U-937 cell lines was detected by CCK-8, clone formation assay, and flow cytometry. In addition, cell apoptosis was detected by Hoechst 33258 fluorescence staining and flow cytometry. At the same time, bioinformatics, RT-qPCR and dual luciferase reporter gene assay were used to predicted and verified the targeting relationship between miR-143 and MALAT-1.@*RESULTS@#Expression of miR-143 in AML patients was significantly lower than those in normal controls. Over-expressed miR-143 could inhibit the proliferation of U-937 cells and promote the apoptosis of the cell. The miR-143 binding site was located on the MALAT-1 RNA sequence, and MALAT-1 was down-regulated in U-937 cells after over-expressed miR-143. However, the expression of miR-143 showed no significantly changed after MALAT-1 silencing.@*CONCLUSION@#Expression of miR-143 in AML patients is lower than that in normal controls. Over-expression of miR-143 can inhibit the proliferation of U-937 cells and promote its apoptosis. And its mechanism may be related to its targe regulation of MALAT-1.

A novel dirigent protein gene with highly stem-specific expression from sugarcane, response to drought, salt and oxidative stresses.

Dirigent and dirigent-like family proteins contain a number of proteins involved in lignification or in the response to pathogen infection and abiotic stress in plants. In the present study, a full-length cDNA sequence of a dirigent-like gene designated ScDir (GenBank Accession Number JQ622282) was obtained from sugarcane based on the stem full-length cDNA library. The ScDir gene was 819-bp long, including a 564-bp ORF encoding 187 amino acid residues. The protein N-terminus contained signal peptides at amino acid residues of 1-25 and transmembrane regions at 7-26 aa. A his-tagged ScDir protein with an estimated molecular mass of 27.4 kDa was expressed in Escherichia coli system. The expressed ScDir protein had increased the host cell's tolerance to PEG and NaCl. When an endogenous GAPDH gene was used as internal control, results from real-time qPCR demonstrated that the ScDir mRNA amount in sugarcane stems was significantly higher than that in the roots, leaves and buds by 18.64 ± 0.48, 25,635.16 ± 2,966.03 and 721.50 ± 8.17-fold, respectively. The ScDir transcript levels in sugarcane seedling increased under H(2)O(2), PEG or NaCl stress. The expression level of ScDir was significantly upregulated under PEG stress, and the highest level was observed at 12 h after stress. Thus, both the ScDir-hosted cell performance and the enhanced expressions in sugarcane imply that the ScDir gene is involved in the response to abiotic stresses of drought, salts and oxidation. The transcription of the ScDir gene is highly stem-specific, as revealed by real-time qPCR. Key message A novel sugarcane Sc-Dir gene, DIRd subfamily, which is highly stalk-specific expression and involved in the response to artificial stresses of drought, salts, and oxidatives.