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T-cell acute lymphoblastic leukemia (T-ALL) is a type of leukemia with high malignant behaviors, which seriously threatens the health of people. It has been reported that circFBXW7 is downregulated in lymphoblastic leukemia. Nevertheless, the exact role of circFBXW7 in T-ALL remains elusive. MTT assay was used to assess the cell viability. Cell apoptosis was assessed by flow cytometry. In addition, mRNA expressions were assessed by RT-qPCR, and a western blot was applied to investigate the protein levels. Meanwhile, the correlation among circFBXW7, miR-494-3p, and SOX1 was explored by RNA pull-down and dual-luciferase reporter assays. Furthermore, a xenograft mice model was conducted to verify the function of circFBXW7 in T-ALL in vivo. CircFBXW7 was significantly downregulated in T-ALL, of which overexpression inhibited the cell viability and induced the apoptosis of Jurkat cells. Moreover, miR-494-3p was identified to be a functional downstream effector to be involved in circFBXW7-mediated T-ALL cell proliferation. Besides, SOX1 was a direct target of miR-494-3p, and the impact of miR-494-3p mimics on T-ALL cell growth was inhibited in the presence of SOX1 overexpression. Furthermore, overexpression of circFBXW7 dramatically inhibited T-ALL tumor growth. In summary, circFBXW7 attenuated the tumorigenesis of T-ALL through the mediation of the miR-494-3p/SOX1 axis, which might be novel targets for T-ALL treatment.

To investigate the effect of the tripartite motif containing 31 (TRIM31) gene silencing on the proliferation and apoptosis of multiple myeloma cells and its possible mechanism.The normal bone marrow plasma cells (nPCs) were selected as control, and the mRNA and protein expression levels of TRIM31 in human multiple myeloma cell lines (U266, RPMI-8226, NCI-H929 and KMS-11) were detected by RT-qPCR and Western blot. Recombinant lentivirol vector containing shRNA-TRIM31 and its negative control were used to infect U266 cells respectively, and the mRNA expression level of TRIM31 in infected cells was detected by RT-qPCR. Then cell proliferation, colony forming and apoptosis were analyzed by CCK-8, soft agar assay, and flow cytometry, respectively. The protein expression levels of TRIM31, cleaved-caspase-3, BCL-2, Bax, p-Akt (Ser473), Akt and PI3K (p110α) were evaluated by Western blot. In addition, the PI3K/Akt signaling pathway-specific inhibitor LY294002 and TRIM31-shRNA lentivirus were used to interfere with U266 cells, and the cell proliferation, apoptosis, and protein expression of p-Akt (Ser473) and Akt were detected by CCK-8, flow cytometry and Western blot, respectively.Compared with nPCs, the expression levels of TRIM31 mRNA and protein in U266, RPMI-8226, NCI-H929 and KMS-11 cells were significantly increased (P0.001), especially in U266 cells. After lentivirus infection, the levels of TRIM31 mRNA and protein in U266 cells were significantly decreased (P0.001). TRIM31 silencing significantly inhibited the proliferation of U266 cells (P0.05), attenuated the ability of cell cloning, improved cell apoptosis, up-regulated the protein expressions of cleaved-caspase-3 and Bas as well as down-regulated expressions of BCL-2, p-Akt (Ser473) and PI3K (p110α). There was no significant effect on Akt protein. Intervention of LY294002 significantly enhanced the inhibition on cell proliferation and the promotion on apoptosis mediated by TRIM31 gene silencing in U266 cells.TRIM31 gene silencing can inhibit U266 cell proliferation and promote its apoptosis, which may be closely related to inhibition of PI3K/Akt signaling pathway.TRIM31基因沉默对U266细胞增殖及凋亡的影响及其机制.探讨三结构域蛋白31（TRIM31）基因沉默对多发性骨髓瘤细胞增殖及凋亡的影响及其可能机制.以正常人骨髓浆细胞为对照，用RT-qPCR和Western blot实验检测人多发性骨髓瘤细胞株（U266、RPMI-8226、NCI-H929和KMS-11）中TRIM31 mRNA和蛋白表达水平。用RT-qPCR法检测含有shRNA-TRIM31的重组慢病毒载体及其对照载体感染之U266细胞中TRIM31 mRNA的水平；用CCK-8、软琼脂克隆形成实验和流式细胞术分别检测细胞增殖活性、克隆形成能力和凋亡率；Western blot检测细胞中TRIM31、cleaved-caspase-3、BCL-2、Bax、p-Akt（Ser473）、Akt和PI3K（p110α）等蛋白的表达水平。用PI3K/Akt信号通路特异性抑制剂LY294002和TRIM31-shRNA慢病毒联合干预U266细胞，用CCK-8、流式细胞术检测细胞增殖活性和凋亡率，Western blot检测细胞中p-Akt（Ser473）和Akt蛋白表达水平.与正常人骨髓浆细胞比较，U266、RPMI-8226、NCI-H929和KMS-11细胞中TRIM31 mRNA和蛋白表达水平显著升高（P0.001），其中U266细胞最为显著；慢病毒感染后，U266细胞中TRIM31 mRNA和蛋白水平显著降低（P0.001）；沉默TRIM31可显著抑制U266细胞增殖（P0.05），降低细胞克隆形成能力，提高细胞凋亡率，并上调cleaved-caspase-3和Bax蛋白水平，下调BCL-2、p-Akt（Ser473）和PI3K（p110α）蛋白水平，而对Akt蛋白无显著影响；LY294002干预显著增强TRIM31基因沉默对U266细胞增殖的抑制作用以及细胞凋亡的促进作用.TRIM31基因沉默可抑制U266细胞增殖，并促进其凋亡，其机制可能与PI3K/Akt信号通路抑制有关.

Background Chronic myeloid leukemia (CML) is a type of cancer that starts in certain blood-forming cells of the bone marrow. LncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), a well known protooncogene, has be shown to be upregulated in various tumor types, including multiple myeloma. However, the biological function of MALAT1 in CML remains has yet to be explored. This study was designed to investigate the effects of MALAT1 on the physiological processes in CML and its underlying mechanisms, which will be helpful for us to have a better understanding of CML development and progression as well as improved therapeutic method. Methods Recombinant virus construction and infection was performed to overexpress or knockdown the expression of MALAT1. Dual luciferase reporter assay was applied to vetify the interaction between MALAT1 and miR-328. The cell viability and cell cycle were analyzed by CCK-8 assay and flow cytometry, respectively. Quantitative real time PCR and western blotting assays were used to measure the expression of genes and proteins. Results The expression of MALAT1 was significantly increased in CML cells compared with peripheral blood cells from health donors. Silencing of MALAT1 significantly inhibited the proliferation and arrested cell cycle of CML cells by targeting miR-328. Moreover, MALAT1 knockdown enhanced imatinib sensitivity of K562 cells, while silencing of miR-328 abolished this effect. Conclusions These findings indicate that lncRNA MALAT1/miR-328 axis promotes the proliferation and imatinib resistance of CML cells, providing new perspectives for the future study of MALAT1 as a therapeutic target for CML.

To construct a eukaryotic expression vector of human tissue factor pathway inhibitor-2 (TFPI-2) and to investigate the effect of TFPI-2 gene on the growth of acute monocytic leukemia cell line (SHI-1).The cDNA of TFPI-2 was obtained by genetic chemical synthesis, the TFPI-2 gene and the linear vector fragment were ligated and inserted into the multiple cloning site of PEGFP-N1 vector, and the eukaryotic expression vector PEGFP-N1-TFPI-2 was transfected SHI-1 cells, then the obtained SHI-1 cells was observed by fluorescence microscopy; MTT assay was used to detect the effect of TFPI-2 gene on the relative growth rate of SHI-1 cells at the different time-point; RT-PCR was used to detect TFPI-2 mRNA expression levels in the cells of each group before and after TFPI-2 transfection; TFPI-2 protein expression was detected by Western blot. The cells which successfully transfected with PEGFP-N1-TFPI-2 vector were named as SHI-1-TFPI-2 (experimental group), and the cells transfected with the empty vector pEGFP-N1 and the untransfected cells were named as SHI-1-V and SHI-1-P and used as the control group.The human TFPI-2 gene eukaryotic expression vector PEGFP-N1-TFPI-2 was successfully constructed, then the transfected into SHI-1 cells, observed by fluorescence microscopy 24 hours later, as a result, the PEGFP-N1-TFPI-2 was successfully transferred into SHI-1 cells, and the number of fluorescent cells increased after 48 h and 72 h. RT-PCR showed that the gray scale ratio of TFPI-2 gene to β- actin in the experimental group was higher than that in the control group. The gray scale ratio was 0.51±0.04 in SHI-1-V group, 0.52±0.03 in SHI-1-P group, 0.87±0.08 in SHI-1-TFPI-2 group, and the difference between SHI-1-TFPI-2 and SHI-1-V, SHI-1-P group was statistically significant (P＜0.05).The expression of TFPI-2 gene in PEGFP-N1-TFPI-2 can inhibit the growth of SHI-1 cells, which provides a research direction for gene therapy of leukemia in the future.携带TFPI-2基因的真核表达载体对SHI-1细胞生长的抑制作用.构建人组织因子途径抑制物-2（TFPI-2）核表达载体，探讨TFPI-2基因对急性单核细胞白血病细胞株（SHI-1）生长的影响。.通过基因化学合成的方式得到TFPI-2的cDNA，将TFPI-2基因和线性载体片段进行连接，并插入载体PEGFP-N1多克隆位点处,再将真核表达载体PEGFP-N1-TFPI-2转染SHI-1细胞, 在荧光显微镜下观察TFPI-2转染SHI-1细胞的情况；应用MTT法检测TFPI-2基因不同时间段对SHI-1细胞相对生长率的影响；RT-PCR检测TFPI-2转染前后每组细胞中TFPI-2 mRNA表达水平；采用Western blot法检测TFPI-2蛋白表达。将成功转染PEGFP-N1-TFPI-2载体的细胞命名为SHI-1-TFPI-2（实验组），转染空载体pEGFP-N1的细胞和未转染细胞设为对照组, 分别命名为SHI-1-V和SHI-1-P。.成功构建了人TFPI-2基因真核表达载体PEGFP-N1-TFPI-2；将载体PEGFP-N1-TFPI-2转染SHI-1细胞，24 h后在荧光显微镜下可见荧光细胞，表明载体PEGFP-N1-TFPI-2成功转入SHI-1细胞； 48和72 h后荧光细胞数目增多。RT-PCR结果显示：TFPI-2基因与内参β- actin条带灰度比值实验组高于对照组，灰度比值分别为：SHI-1-V组：0.51±0.04、SHI-1-P组：0.52±0.03、SHI-1-TFPI-2组：0.87± 0.08；SHI-1-TFPI-2组与SHI-1-V和SHI-1-P组比较差异有统计学意义（P＜0.05）。.PEGFP-N1-TFPI-2中TFPI-2基因的表达能抑制SHI-1细胞生长，此为未来白血病的基因治疗提供了研究方向。.

Multidrug resistance (MDR) has become the major cause of failure chemotherapy for leukemia and high mortality of leukemia. The study aimed to investigate whether the let-7f mediate the Adriamycin (ADR) resistance of leukemia, and to explore the potential molecular mechanism. Cell proliferation was examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and the soft agar clone formation assay. Flow cytometry was performed to detected cell cycle and apoptosis. The targeted regulationship was analyzed by dual-luciferase assay. Real-time polymerase chain reaction and Western blot were used to measure the expressions of let-7f, ABCC5, ABCC10, cell cycle-related proteins, and apoptosis-related proteins. The xenograft mouse model was used to conduct the tumor formation assay in vivo. The results demonstrated that the expression of let-7f was lower in multidrug-resistant K562/A02 cell lines compared to that in K562, while ABCC5 and ABCC10 were upregulated. Overexpression of let-7f in K562/A02 cell lines downregulated the ABCC5 and ABCC10 expression, enhanced cell sensitivity to ADR, promoted cell apoptosis, and inhibited cell proliferation. let-7f was proved to negatively regulate ABCC5 and ABCC10. Tumor formation assay further determined that let-7f overexpression increased sensitivity to ADR. Taken together, the let-7f downregulation induced the ADR resistance of leukemia by upregulating ABCC5 and ABCC10 expression. Our study provided a novel perspective to study the mechanism of MDR and a new target for the reversal of MDR.

To study the inhibitory effect of serum containing Fuzheng Jiedu decoction on leukemia multi-drug-resistance K562/A02 cells and its possible mechanism.The MTT method was used to detect the inhibitory rate of K562/AO2 cells treated with serum containing Fuzheng Jiedu decoction; the flow cytometry was used to detect the inhibitory effect of serum containing medicin on growth of K562/AO2 cells and P-gp expression; the Q-PCR was used to assay the BCL-2 mRNA expression; the Western blot was used to detect the BCL-2 protein expression.MTT cytotoxic test showed serum containing Fuzheng Jiedu decoction could inhibit K562/A02 cell growth, and the inhibitory rate increased with the increase of drug concentration; the flow cytometry showed that the serum containing Fuzheng Jiedu decoction could promote K562/A02 cell apoptosis in a concentration-dependent manner. qPCR and Western blot showed that serum containing Fuzheng Jiedu decoction could down-regulate the protein expression of BCL-2. Fuzheng Jiedu decoction could reduce the protein expression of P-gp on the K562/A02 cell membrane.serum containing Fuzheng Jiedu decoction can promote K562/A02 cell apoptosis, its mechanism of inducing apoptosis may be related with the inhibition of BCL-2 and P-gp protein expression.

Chemotherapy resistance is still the main clinical limitation to the successful treatment of leukemia. The underlying mechanisms of drug resistance are not fully understood. Recently, research on m...

To explore the relationship between microRNA and drug resistance in leukemia treatment by screening and identifying the microRNAs which differentially express in K562 cell line and its adriamycin resistant cells-K562/A02 cell line.The drug resistance potency of K562/A02 cells was evaluated by MTT assay. P-gp expression of K562 and K562/A02 cells were detected by flow cytometry (FCM). The differentially expressed microRNAs in K562 and K562/A02 cells were analyzed by microarray technique and Real Time RT-PCR.The resistance to adriamycin (ADM) of K562/A02 cells was 180 fold greater than that of K562 cells. P-gp expression rate of K562 and K562/A02 cells was 0.2% and 86%, respectively. Twenty-two microRNAs expressed differentially in K562 and K562/A02 cells (P0.01). As compared to K562 cells, expressions of miR-221, miR-155 and miR-451 were up-regulated by more than two fold, while expression of miR-98, miR-181a, let-7f, let-7g, miR-424 and miR-563 down-regulated by more than two fold in K562/A02 cells. The results of real time RT-PCR were consistent with that of microarray. Of note, differential expressions of miR-451, miR-155, miR-221, let-7f and miR-424 were remarkable.K562/A02 cells show a different microRNA expression profile as compared to its parental K562 cells, suggesting microRNAs including miR-221, miR-155, miR-451, let-7f and miR-424 may be involved in the mechanism of drug resistance in leukemia. These differentially expressed microRNAs provide potential novel targets for overcoming drug-resistance.

In the present study, 90 patients with newly diagnosed acute promyelocytic leukemia (APL) were studied for all-trans retinoic acid (ATRA) and arsenic trioxide (As2O3) combination treatment in remission induction and postremission therapy. In addition, 20 APL patients who had achieved complete remission (CR) with an ATRA-based regimen received ATRA/As2O3 combination for consolidation and maintenance were also enrolled. The results showed that ATRA/As2O3 combination therapy yielded a high CR rate of 93.3% and a significantly shorter time to enter CR (median: 31 days; range: 18–59 days) compared to the ATRA-based regimen (n = 72; median: 39 days; range: 25–62 days). With the ATRA/As2O3 combination for CR maintaining, regardless of the way by which CR was attained, the relapse-free survival was significantly better than with an ATRA plus cytotoxic chemotherapy regimen (92.9 ± 3.2% vs. 72.4 ± 7.6%, for the 3-year Kaplan-Meier estimate of relapse-free survival). The drug toxicity profile showed that with the use of As2O3, the incidence of hepatotoxicity was obviously high during remission induction but decreased significantly during postremission treatment. We conclude that APL patients may benefit from the early use of the combination of ATRA and As2O3, in either remission induction or consolidation/maintenance.