MicroRNAs have been shown to play an important role in normal hematopoisis and leukemogenesis. Here, we report function and mechanisms of miR-181 family in myeloid differentiation and acute myeloid leukemia (AML). The aberrant overexpression of all the miR-181 family members (miR-181a/b/c/d) was detected in French-American-British M1, M2 and M3 subtypes of adult AML patients. By conducting gain- and loss-of-function experiments, we demonstrated that miR-181a inhibits granulocytic and macrophage-like differentiation of HL-60 cells and CD34+ hematopoietic stem/progenitor cells (HSPCs) by directly targeting and downregulating the expression of PRKCD (which then affected the PRKCD-P38-C/EBPα pathway), CTDSPL (which then affected the phosphorylation of retinoblastoma protein) and CAMKK1. The three genes were also demonstrated to be the targets of miR-181b, miR-181c and miR-181d, respectively. Significantly decreases in the expression levels of the target proteins were detected in AML patients. Inhibition of the expression of miR-181 family members owing to Lenti-miRZip-181a infection in bone marrow blasts of AML patients increased target protein expression levels and partially reversed myeloid differentiation blockage. In the mice implanted with AML CD34+ HSPCs, expression inhibition of the miR-181 family by Lenti-miRZip-181a injection improved myeloid differentiation, inhibited engraftment and infiltration of the leukemic CD34+ cells into the bone marrow and spleen, and released leukemic symptoms. In conclusion, our findings revealed new mechanism of miR-181 family in normal hematopoiesis and AML development, and suggested that expression inhibition of the miR-181 family could provide a new strategy for AML therapy.
Long noncoding RNAs (lncRNAs) play important regulatory roles in a variety of diseases, including many tumors. However, the functional roles of these transcripts and mechanisms responsible for their deregulation in pancreatic ductal adenocarcinoma (PDAC) are not thoroughly understood. In this study, we discovered that lncRNA MIR31HG is markedly upregulated in PDAC. Knockdown of MIR31HG significantly suppressed PDAC cell growth, induced apoptosis and G1/S arrest, and inhibited invasion, whereas enhanced expression of MIR31HG had the opposite effects. Online database analysis tools showed that miR-193b could target MIR31HG and we found an inverse correlation between MIR31HG and miR-193b in PDAC specimens. Inhibition of miR-193b expression significantly upregulated the MIR31HG level, while overexpression of miR-193b suppressed MIR31HG's expression and function, suggesting that MIR31HG is negatively regulated by miR-193b. Moreover, using luciferase reporter and RIP assays, we provide evidence that miR-193b directly targeted MIR31HG by binding to two microRNA binding sites in the MIR31HG sequence. On the other hand, MIR31HG may act as an endogenous ‘sponge' by competing for miR-193b binding to regulate the miRNA targets. Collectively, these results demonstrate that MIR31HG functions as an oncogenic lncRNA that promotes tumor progression, and miR-193b targets not only protein-coding genes but also the lncRNA, MIR31HG.
ACE2 appears to counterbalance the vasopressor effect of angiotensin I converting enzyme (ACE) in the reninangiotensin system. We hypothesized that ACE2 polymorphisms could confer a high risk of hypertension and have an impact on the antihypertensive response to ACE inhibitors. The hypothesis was tested in two casecontrol studies and a clinical trial of 3,408 untreated hypertensive patients randomized to Atenolol, Hydrochlorothiazide, Captopril, or Nifedipine treatments for 4 weeks. ACE2 rs2106809 T allele was found to confer a 1.6-fold risk for hypertension in women (95% confidence interval (CI), 1.132.06), whereas when combined with the effect of the ACE DD genotype, the risk was 2.34-fold (95% CI, 1.754.85) in two independent samples. The adjusted diastolic blood pressure response to Captopril was 3.3 mm Hg lower in ACE2 T allele carriers than in CC genotype carriers (P=0.019) in women. We conclude that the ACE2 T allele confers a high risk for hypertension and reduced antihypertensive response to ACE inhibitors.
BACKGROUND AND PURPOSEThe resistance of CA3 neurons to ischaemia and the ischaemic tolerance conferred by ischaemic preconditioning (IPC) are two well-established endogenous neuroprotective mechanisms. Elucidating the molecules involved may help us find new therapeutic targets. Thus, we determined whether dynamin-related protein 1 (Drp-1) is involved in these processes. EXPERIMENTAL APPROACHIn vivo, we subjected rats to either 10 min severe global ischaemia using a four-vessel occlusion (4-VO) model or 2 min IPC before the onset of 4-VO. In vitro, we performed oxygen glucose deprivation (OGD) studies in rat hippocampal neurons. Drp-1 was silenced or inhibited by siRNA or pharmacological inhibitor Mdivi1. To assess whether mitochondrial Drp-1 alters neuronal vulnerability to ischaemic injury, various approaches were used including western blot, immunohistochemistry, immunofluorescence staining and electron microscopy. Hippocampal function was assessed using an open-field test. KEY RESULTSMitochondrial dynamin-related protein 1 (mtDrp-1) was selectively induced by ischaemia in hippocampal CA3 neurons. In hippocampal CA1 neurons, mtDrp-1 was not affected by ischaemia but significantly up-regulated by IPC. Suppression of Drp-1 increased the vulnerability of cells to OGD and global ischaemia. Inhibition of Drp-1 in vivo resulted in loss of acquisition and encoding of spatial information, and also prevented ischaemia-induced mitophagy in CA3. Thus mitochondrial-mediated injury was amplified and resistance to ischaemic injury lost. CONCLUSIONS AND IMPLICATIONSOur findings that Drp-1 increases the resistance of neurons of hippocampal CA3 affected by global ischaemia and contributes to the tolerance conferred by IPC highlight Drp-1 as a potential therapeutic target for brain ischaemic stroke. AbbreviationsCCA, common carotid arteries; Drp-1, dynamin-related protein 1; H/I, hypoxia/ischaemia; IPC, ischaemic preconditioning; mtDrp-1, mitochondrial Drp-1; OGD, oxygen glucose deprivation; 4-VO, four-vessel occlusion
Summary Gene amplification and enhanced expression of the epidermal growth factor receptor (EGFR) represent the major molecular genetic alteration in glioblastomas and it may play an essential role in cell growth and in the carcinogenic process. On the other hand, the nuclear suppressor proteins PML and p53 are also known to play critical roles in cancer development and in suppressing cell growth. Here we report that, in glioblastoma cells with defective EGFR function, the expressions of both promyelocytic leukaemia (PML) and p53 were altered. Cells that were transfected with the antisense-cDNA of EGFR were found to have more cells in G1 and fewer cells in S phase. In addition, the transfected cells were found to be non-responsive to EGF-induced cell growth. Interestingly, the expression of the suppressors p53 and PML were found to be significantly increased by immunohistochemical assay in the antisense-EGFR cells. Moreover, the PML expression in many of the cells was converted from the nuclear dot pattern into fine-granulated staining pattern. In contrast, the expressions of other cell cycle regulated genes and proto-oncogene, including the cyclin-dependent kinase 4 (cdk4), retinoblastoma, p16INK4a and p21H-ras , were not altered. These data indicate that there are specific inductions of PML and p53 proteins which may account for the increase in G1 and growth arrest in antisense-EGFR treated cells. It also indicates that the EGF, p53 and PML transduction pathways were linked and they may constitute an integral part of an altered growth regulatory programme. The interactions and cross-talks of these critical molecules may be very important in regulating cell growth, differentiation and cellular response to treatment in glioblastomas.
In an earlier study we showed that C10ORF97 (chromosome-10, open reading frame-97) was expressed in almost all of the tissues and cell lines tested, and that it inhibited the growth of seven tumor cell lines, including two lung carcinoma cell lines (A549 and PG). Here, we show that C10ORF97 is downregulated in non-small-cell lung cancer (NSCLC) tissue compared with normal lung tissue. Overexpression of C10ORF97 significantly suppressed human lung carcinoma A549 cell growth (proliferation and anchorage-independent growth in soft agar) and motility (migration and adhesion). This tumor-suppressive function of C10ORF97 was also verified in vivo. We further found that C10ORF97 caused G 1 arrest of A549 cells and modulated the expression level of several cell-cycle regulators (such as CDK2, cyclin-E and p27). These effects of C10ORF97 were mediated by physical association between C10ORF97 and Jun-activating domain-binding protein-1 (JAB1), and blocking of JAB1-mediated translocation of p27 from the nucleus to the cytoplasm. Together, these results indicated that C10ORF97 functions as a novel tumor suppressor by modulating several key G 1 /S-regulatory proteins by interacting with JAB1. These findings led us to hypothesize that a single-nucleotide polymorphism (SNP) in the C10ORF97 gene that affects its expression might be associated with susceptibility to NSCLC. SNP216 C4T (rs2297882) in the C10ORF97 Kozak sequence was identified, and allele T of SNP216 suppressed C10ORF97 expression in vitro and in vivo. Furthermore, the TT genotype of SNP216 was associated with an increased risk of NSCLC (adjusted odds ratio ¼ 1.73 (95% confidence interval: 1.33-2.25), P ¼ 4.6 Â 10 -5). These data indicated that C10ORF97 is a tumor suppressor of NSCLC progression and C10ORF97-SNP216 may serve as a predictor of NSCLC.
Current clinical approaches to osteoporosis primarily target osteoclast biology, overlooking the synergistic role of bone cells, immune cells, cytokines, and inorganic components in creating an abnormal osteoporotic microenvironment. Here, metal-polyDNA nanoparticles (Ca-polyCpG MDNs) composed of Ca 2+ and ultralong single-stranded CpG sequences were developed to reconstruct the osteoporotic microenvironment and suppress osteoporosis. Ca-polyCpG MDNs can neutralize osteoclast-secreted hydrogen ions, provide calcium repletion, promote remineralization, and repair bone defects. Besides, the immune-adjuvant polyCpG in MDNs could induce the secretion of osteoclastogenesis inhibitor interleukin-12 and reduce the expression of osteoclast function effector protein to inhibit osteoclast differentiation, further reducing osteoclast-mediated bone resorption. PPi 4− generated during the rolling circle amplification reaction acts as bisphosphonate analog and enhances bone targeting of Ca-polyCpG MDNs. In ovariectomized mouse and rabbit models, Ca-polyCpG MDNs prevented bone resorption and promoted bone repair by restoring the osteoporotic microenvironment, providing valuable insights into osteoporosis therapy.
Objectives: Deficiency of adenosine deaminase 2 (DADA2) is a rare disease with varying phenotypes and disease outcomes. We evaluated the treatment of DADA2 and explored the factors associated with disease outcome. Methods: A systemic literature review of DADA2 was conducted. Cases were included if they had documented detailed genotypes, phenotypes, treatment protocols, and outcomes. Patients were categorized as having uncontrolled and controlled disease. Factors associated with disease outcome were analyzed using logistic regression models. Results: The study population comprised 242 DADA2 patients with data on treatment protocols and responses, of whom 17 required no treatment. Tumor necrosis factor a inhibitors (TNFi) were effective in 78.6% (103/131). Hematological abnormalities and increased acute phase reactants are independently associated with the effectiveness of TNFi (OR, 0.21 [95%CI, 0.07-0.661; P=.007] and 9.62 [95%CI, 2.31-40.00; P=.002, respectively). Among the 225 patients requiring active treatment, 157 (69.8%) had controlled disease and 68 (30.2%) uncontrolled disease. Neither age of disease onset nor genotype was associated with disease outcome. Increased acute phase reactant values, constitutional symptoms, neurological symptoms, and treatment with TNFi were independently associated with disease control, while recurrent infections and severe vascular events were the main causes of mortality (10/21 and 6/21, respectively). Conclusion: In patients requiring treatment, symptoms of systemic inflammation and vasculitis and treatment with TNFi are associated with disease control. Recurrent infections and severe vascular events should be treated intensively, as they are the main causes of death. Hematological abnormalities should be monitored, as they decrease the effectiveness of TNFi.
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