Effect of MiR-424-5p on the Drug Resistance of Diffuse Large B-Cell Lymphoma Cells by Regulating PD-1/PD-L1 Signaling Pathway / 中国实验血液学杂志

OBJECTIVE@#To explore the effect of microRNA-424-5p (miR-424-5p) on the drug resistance of diffuse large B-cell lymphoma (DLBCL) cells by regulating the programmed death receptor-1 (PD-1)/programmed death ligand-1 (PD-L1) signaling pathway.@*METHODS@#Human DLBCL cell line CRL2631 cells were induced to construct CRL2631-CHOP resistant cell line. RT-qPCR and Western blot were used to detect the expression levels of MiR-424-5p, PD-L1 mRNA and protein, and multidrug resistance gene-1 (MDR-1) protein in CRL2631 cells and CRL2631-CHOP cells, respectively. The target genes of MiR-424-5p was verified by dual luciferase reporter assay. The miRNA simulation/interference technology and thiazole blue (MTT) method were used to detect the resistance of CRL2631 cells and CRL2631-CHOP cells to CHOP.@*RESULTS@#Compared with CRL2631 cells, the drug resistance of CRL2631-CHOP cells to CHOP and the levels of MDR-1 protein (P<0.05), PD-L1 mRNA and protein in the cells were significantly increased (both P<0.001), while the relative level of MiR-424-5p was significantly reduced (P<0.001). The result of the dual luciferase reporter assay showed that PD-L1 was the direct downstream target gene of MiR-424-5p (P<0.001). After transfection of MiR-424-5p inhibitor, the resistance of CRL2631 cells to CHOP drugs increased, and the expression level of MDR-1 protein (P<0.01), PD-L1 mRNA and protein also increased significantly (both P<0.01). After transfection of MiR-424-5p mimics, the resistance of CRL2631-CHOP cells to CHOP drugs decreased, and the expression level of MDR-1 protein (P<0.001), PD-L1 mRNA and protein also decreased significantly (both P<0.001). Overexpression of PD-L1 could reverse the inhibitory effect of upregulating MiR-424-5p on PD-L1 (P<0.001).@*CONCLUSION@#Down-regulation of MiR-424-5p enhances the drug resistance of DLBCL cells by regulating the PD-1/PD-L1 signaling pathway.

Effect of Arsenic Trioxide on K562 Cell Proliferation and Its Mechanism / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the molecular mechanism of arsenic trioxide(ATO) inhibiting K562 cell proliferation, and explore the new targets for treating chronic myeloid leukemia(CML).</p><p><b>METHODS</b>human CML cell line K562 cells were cultured in vitro, and were treated with different concentrations of ATO; MTT was used to detect the cell proliferation; flow cytometry(FCM) was used to determine cell apoptosis, cell cycle and the expression of CD44; Transcriptional levels of β-catenin and cyclin D1 were assayed by RT-PCR.</p><p><b>RESULTS</b>2 µmol/L ATO could inhibit the cell proliferation obviously in a time-and-dose-dependent manner. With drug concentration increasing and time prolonging, the expression rate of CD44 was declined gradrually. FCM with AnnexinV/PI double staining showed that K562 cells were induced to apoptosis after exposure to 2.5-10 µmol/L ATO for 48 hours and in dose-dependent manner. Treating with different concentration ATO for 48 hours, cell ratio of G/Gphase increased and cell ratio in S phase decreased gradually. RT-PCR showed that the expression of β-catenin and CyclinD1 decreased with increasing of drug concentration.</p><p><b>CONCLUSION</b>ATO in certain concentration range can inhibit K562 cell proliferation, and induce the cell apotosis, the mechanismin influencing the Wnt/β-catenin pathway may be the downregulation of CD44 expression, arresting K562 cells in G/Gphase, and affecting the gene transcription, thus inhibiting K562 cell proliferation.</p>

Effect of Anti-CD44 Monoclonal Antibody A3D8 on Expression of AP-1 in HL-60 Cells / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To explore the effect of anti-CD44 monoclonal antibody A3D8 on expression of transcription factor AP-1 in acute myeloid leukemia cells.</p><p><b>METHODS</b>After acute leukemia cell line HL-60 was treated by different concentrations of A3D8, the proliferation and cell cycle were detected by MTT and FCM respectively. The expressions of c-JUN and c-FOS at mRNA and protein level were detected by RT-PCR and Western Blot respectively.</p><p><b>RESULTS</b>The proliferation of HL-60 was inhibited by A3D8. The A3D8 treatment increased the percentage of G/Gcells. The expressions of c-JUN at mRNA and protein level were both decreased in HL-60 cells treated with A3D8. The expressions of c-FOS at mRNA and protein level in rapamycin treatment groups showed no statistically significant difference as compared with that in control group.</p><p><b>CONCLUSIONS</b>A3D8 can affect the activity of AP-1 through inhibiting the expressions of c-JUN at mRNA and protein level.</p>

Research Progress on CALR Mutation in the Myeloproliterative Neoplasm -Review / 中国实验血液学杂志

There is no gold diagnostic standard for BCR-ABL fusion gene negative chronic myeloproliterative neoplasm(cMPN). The following detection methods such as comprehensive bone marrow cell morphology, bone marrow pathology, genetic mutation, flow cytometry and immunohistochemical are needed to diagnose the BCR-ABL fusion gene positive cMPN. The JAK2 mutation can be used as a specific diagnostic criteria for polycythemia vera (PV), but there is no specific and sensitive indication for the JAK2 mutation-negative MPN. CALR mutation would be an indication in a certain extent. In this review, the CALR mutation detection, detection mean and its correlation with disease diagnosis and prognosis etc were summarized.

Effect of COX-2 inhibitor celecoxib on proliferation, apoptosis of HL-60 cells and its mechanism / 中国实验血液学杂志

This study was aimed to investigate the effect of COX-2 inhibitor celecoxib on proliferation, apoptosis of human acute myeloid leukemia cell line HL-60 and its mechanism. HL-60 cells were cultured with different concentrations of celecoxib for 24 h. Cell proliferation was analyzed by CCK-8 assay, cell apoptosis and cell cycle distribution were detected by flow cytometry. Cyclin D1, cyclin E1 and COX-2 mRNA expressions were determined by RT-PCR. The results showed that after the HL-60 cells were treated with different concentrations of celecoxib for 24 h, the cell growth was significantly inhibited in a dose-dependent manner(r = 0.955), IC50 was 63.037 µmol/L of celecoxib. Celecoxib could effectively induce apoptosis in HL-60 cells also in dose-dependent manner(r = 0.988), blocked the HL-60 cells in the G0/G1 phase. The expression of cyclin D1, cyclin E1 and COX-2 mRNA were downregulated. It is concluded that celecoxib can inhibit the proliferation of HL-60 cells in dose-dependent manner, celecoxib causes cell G0/G1 arrest and induces cell apoptosis possibly through down-regulation of the cyclin D1 and cyclin E1 expression, and down-regulation of COX-2 expression respectively.

IL-23 alone or with IL-2 induces the killing effect of hPBMNC on K562 cells / 中国实验血液学杂志

This study was aimed to explore the killing effect of PBMNC induced by IL-23 alone or combined with IL-2 on K562 cells and its mechanism. The PBMNC were induced in vitro by IL-23 (50 ng/ml) alone or IL-23 combined with IL-2 (100 U/ml) for 72 h, and then were co-cultured with leukemia cell line K562. The CCK-8 method was used to detect the effect of PBMNC induced at different times on K562 cells, the ELISA was performed for detecting IFN-γ level in culture supernatant, and the perforin and granzymes B were detected by RQ-PCR. The results showed that the killing effect of PBMNC induced by IL-23 alone or IL-23 combined with IL-2 on K562 cells was observed, and obviously enhanced with prolonging of time, moreover, there was statistical difference among different time points (P < 0.05). The IFN-γ level in supernatant of PBMNC cultured with cytokines significantly increased, and the IFN-γ levels in group of IL-23 combined with IL-2 were higher than that in other groups (P < 0.05). The mRNA expressions level of perforin and granzymes B of the expanded PBMNC in groups cultured with cytokines were higher than that in control group (P < 0.05), and the mRNA expressions of perforin and granzymes B in group of IL-23 combined with IL-2 were significantly higher than that in others (P < 0.05). It is concluded that IL-23 can promote the killing effect of PBMNC on K562 cells. The combination of IL-2 with IL-23 displays synergic effect and a time-dependent manner. IL-23 also enhances the expression of IFN-γ, perforin and granzyme B in PBMNC. Its combination with IL-2 displays synergistic effect, suggesting that the anti-leukemic activity of IL-23 may be realized through inducing PBMNC to express IFN-γ, perforin and granzyme B.