5-Aza-dC promotes T-cell acute lymphoblastic leukemia cell invasion via downregulation of DNMT1 and upregulation of MMP-2 and MMP-9.

5-Aza-2'-deoxycytidine (5-Aza-dC) is a demethylation agent known to deplete DNA methyltransferases (DNMTs) in leukemia cancer cells, and can restore the expression of their target genes in Jurkat cells. The goal of this study was to discern the potential effect of 5-Aza-dC on the invasion of T-ALL cells in acute lymphoblastic leukemia (ALL). The role of matrix metallopeptidase (MMP)-2, MMP-9, and DNMT1 in cell invasion was determined using loss- and gain-of-function investigations in Jurkat- and Sup-T1-R cells. A nude mouse model of ALL was established for further exploration of their roles in vivo. MMP-2 and MMP-9 exhibited high expression and low DNA methylation levels in 5-Aza-dC-resistant T-ALL cells. DNMT1 was poorly expressed in 5-Aza-dC-resistant T-ALL cells and exhibited decreased enrichment in the promoter region of MMP-2 and MMP-9. Silencing of MMP-2 and MMP-9 or DNMT1 overexpression reduced T-ALL cell invasion. After treatment of Sup-T1 cells with 5-Aza-dC, MMP-2 and MMP-9 presented with reduced DNA methylation levels but increased expression, and DNMT1 expression was identified to be suppressed. Further, in vivo assays revealed that DNMT1 alleviated T-ALL by reducing the expression of MMP-2 and MMP-9 in vivo. All in all, 5-Aza-dC activates MMP-2 and MMP-9 expression by reducing DNMT1-dependent DNA methylation levels and, hence, promotes the invasion of T-ALL cells.

The Effects of the Ecological Conservation Redline in China: A Case Study in Anji County.

The Ecological Conservation Redline (ECR) of China plays an important role in avoiding ecological space occupancy and maintaining regional ecological security. Anji County in Zhejiang Province is one of the first regions to implement the ECR in China. This paper takes Anji County as an example to analyze the effects of ECR. To do this, we first set up two scenarios with the CLUE-S model: a normal land-use development scenario (NLDS) and an ECR implementation scenario (ECRS); then we compare the land use of 2010 and 2015 under NLDS and ECRS. Land use, ecosystem services value (ESV), landscape metrics, and ecological product outputs were compared between the entire county and the ECR areas. The results revealed the following: (1) From 2000 to 2015, the ecological land in Anji County decreased by 4.03%, while it decreased by 1.17% in the ECR areas. (2) In the ECR areas, there was less arable land and construction land of the ECRS than in the NLDS, which indicates the ECR impeded the expansion of construction land and arable land in the ECR areas. (3) The ECR areas account for 39% of Anji County but contribute more than 80% to the ESV of the whole county. During 2000-2015, the ESV of the entire county decreased while the ESV of the ECR areas increased. (4) From 2000 to 2015, whereas landscape fragmentation of the entire county increased, that of ECR areas decreased. (5) Since the ECR's implementation, Anji County has vigorously developed the bamboo industry, ecological agriculture, the tourism industry, and achieved rapid economic development via industrial restructuring and transformation. On the whole, the ECR has neither adversely affected land development nor economic development but instead has promoted the optimization of the land's spatial development pattern.

Circ_0003645 serves as miR-335-5p sponge to promote the biological process of diffuse large B-cell lymphoma by upregulating NFIB.

BACKGROUND: Circular RNAs (circRNAs) are critical regulators for the development of many tumours, including diffuse large B-cell lymphoma (DLBCL). However, the role and mechanism of circ_0003645 in DLBCL progression remains obscure. METHODS: Quantitative real-time PCR was performed to measure the expression of circ_0003645, microRNA (miR)-335-5p and nuclear factor I/B (NFIB). Cell viability, apoptosis and cell cycle were measured by cell counting kit 8 assay and flow cytometry. Protein expression was assessed using western blot analysis, and cell glycolysis was evaluated by detecting glucose consumption and ATP/ADP ratios. Besides, dual-luciferase reporter assay and RIP assay were used to confirm RNA interaction. RESULTS: Our data showed that circ_0003645 expression was significantly upregulated in DLBCL tumour tissues. After circ_0003645 knockdown, the viability, cell cycle and glycolysis of DLBCL cells were inhibited, while cell apoptosis was promoted. MiR-335-5p could be sponged by circ_0003645, and NFIB was confirmed to be a downstream target of miR-335-5p. Function analysis revealed that anti-miR-335-5p reversed the regulation of si-circ_0003645 on DLBCL cell progression, and NFIB overexpression also abolished miR-335-5p-mediated the biological functions of DLBCL cells. CONCLUSION: The present study revealed that circ_0003645 promoted the proliferation and glycolysis of DLBCL cells by the miR-335-5p/NFIB axis, which might provide a novel insight for DLBCL treatment.

DNA methylation-mediated silencing of microRNA-204 enhances T cell acute lymphoblastic leukemia by up-regulating MMP-2 and MMP-9 via NF-κB.

T cell acute lymphoblastic leukaemia (T-ALL) is a highly aggressive haematological cancer of the bone marrow. The abnormal expression of microRNAs (miRNAs) is reportedly involved in T-ALL development and progression. Thus, we aimed to decipher the involvement of miR-204 silencing mediated by DNA methylation in the occurrence of T cell acute lymphoblastic leukaemia (T-ALL). miR-204 expression was determined in bone marrow and peripheral blood samples from T-ALL patients by real-time quantitative PCR (RT-qPCR) with its effect on cell proliferation evaluated by functional assays. In addition, bisulphite sequencing PCR was employed to detect the DNA methylation level of the miR-204 promoter region, and the binding site between miR-204 and IRAK1 was detected by luciferase assay. We found that miR-204 was down-regulated in T cells of T-ALL patients, which was caused by the increased DNA methylation in the promoter region of miR-204. Moreover, overexpression of miR-204 inhibited T-ALL cell proliferation while enhancing their apoptosis through interleukin receptor-associated kinase 1 (IRAK1), which enhanced the expression of matrix metalloproteinase-2 (MMP-2) and MMP-9 through activation of p-p65. Thus, miR-204 modulated MMP-2 and MMP-9 through IRAK1/NF-κB signalling pathway, which was confirmed by in vivo assay. Taken together, DNA methylation-mediated miR-204 silencing increased the transcription of IRAK1, thus activating the NF-κB signalling pathway and up-regulating the downstream targets MMP-2/MMP-9.