CircFBXW7 inhibits the tumorigenesis of T-cell acute lymphoblastic leukemia through modulating miR-494-3p/SOX1 axis.

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.

Comprehensive analysis on the expression profile and prognostic values of Synaptotagmins (SYTs) family members and their methylation levels in gastric cancer.

Synaptotagmins (SYTs), constitute a family of 17 membrane-trafficking protein, palying crucial roles in the development and progression of human cancers. However, only very few studies have investigated the expression profile and prognostic values of SYTs family members in gastric cancer (GC). Therefore, we comprehensively evaluated the expression, methylation, prognosis and immune significance of SYTs family members through bioinformatics analysis from the online databases in GC. The expressions of SYT4, SYT9, and SYT14 were up-regulated, and negatively associated with their methylation levels in GC. Both the over-expression of SYT4, SYT9 and SYT14 and their hypomethylation levels contributed to an unsatisfactory overall survival (OS) and progression-free survival (PFS) in GC. Moreover, the low expressions of several methylation cg sites (cg02795029, cg07581146, cg15149095, cg19922137, cg25371503, cg26158959, cg02269161, cg03226737, cg08185661, cg16437728, cg22723056 and cg24678137) were significantly correlated with an unfavorable OS and PFS in GC. Furthermore, the expression of SYT4, SYT9 and SYT14 played a pivotal role in immune cells infiltration in GC. Collectively, our current finding suggested that SYT4, SYT9 and SYT14 might be potent prognostic indictors and promising immunotherapeutic targets for GC patients.

[Effect of TRIM31 Gene Silencing on the Proliferation and Apoptosis of U266 Cells and Its Mechanism].

OBJECTIVE: 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. METHODS: 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. RESULTS: Compared with nPCs, the expression levels of TRIM31 mRNA and protein in U266, RPMI-8226, NCI-H929 and KMS-11 cells were significantly increased (P<0.001), especially in U266 cells. After lentivirus infection, the levels of TRIM31 mRNA and protein in U266 cells were significantly decreased (P<0.001). TRIM31 silencing significantly inhibited the proliferation of U266 cells (P<0.05), 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. CONCLUSION: TRIM31 gene silencing can inhibit U266 cell proliferation and promote its apoptosis, which may be closely related to inhibition of PI3K/Akt signaling pathway.

Downregulation of microRNA let-7f mediated the Adriamycin resistance in leukemia cell line.

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.

[Research on quantitative structure-property relationships for n-octanol/water partition coefficients of phthalic acid esters].

Quantum chemical parameters based on the PM3 method were calculated for phthalic acid esters (PAEs). Using partial least squares (PLS) algorithm, a quantitative structure-property relationships (QSAR) model for the n-octanol/water partition coefficients (K(ow)) of PAEs was developed. The result indicates that the model has a good stability and predicting ability. It can be concluded from this study that the main factors affecting IgK(ow) of PAEs are total energy (TE), relative molecular weight (M(r)), average molecular polarizability (alpha) and standard heat of formation (deltaH(f)). The IgK(ow) values increase with increasing M(r) and a values. In contrast, increasing TE and deltaH(f) values leads to the decrease of IgK(ow).