In leukemia, knock-down of the death inducer-obliterator gene would inhibit the proliferation of endothelial cells by inhibiting the expression of CDK6 and CCND1.

BACKGROUND: Endothelial cells (ECs) are a critical component of the hematopoietic niche, and the cross-talk between ECs and leukemia was reported recently. This study aimed to determine the genes involved in the proliferation inhibition of endothelial cells in leukemia. METHODS: Human umbilical vein endothelial cells (HUVEC) were cultured alone or co-cultured with K562 cell lines. GeneChip assays were performed to identify the differentially expressed genes. The Celigo, MTT assay, and flow cytometric analysis were used to determine the effect of RNAi DIDO on cell growth and apoptosis. The differently expressed genes were verified by qRT-PCR (quantitative real-time PCR) and western-blot. RESULTS: In K562-HUVEC co-cultured cell lines, 323 down-regulated probes were identified and the extracellular signal-regulated kinase 5 (ERK5) signaling pathway was significantly inhibited. Among the down-regulated genes, the death inducer-obliterator gene (DIDO) is a part of the centrosome protein and may be involved in cell mitosis. As shown in the public data, leukemia patients with lower expression of DIDO showed a better overall survival (OS). The HUVEC cells were infected with shDIDO lentivirus, and reduced expression, inhibited proliferation, and increased apoptosis was observed in shDIDO cells. In addition, the expression of Cyclin-Dependent Kinase 6 (CDK6) and Cyclin D1 (CCND1) genes was inhibited in shDIDO cells. Finally, the public ChIP-seq data were used to analyze the regulators that bind with DIDO, and the H3K4me3 and PolII (RNA polymerase II) signals were found near the Exon1 and exon2 sites of DIDO. CONCLUSION: The knock-down of DIDO will inhibit the proliferation of endothelial cells in the leukemia environment. The expression of DIDO may be regulated by H3K4me3 and the inhibition of DIDO may lead to the down-regulation of CDK6 and CCND1. However, how DIDO interacts with CDK6 and CCND1 requires further study.

Characterization of microbiota in acute leukemia patients following successful remission induction chemotherapy without antimicrobial prophylaxis.

PURPOSE: In the present study, we characterized the microbiomes of acute leukemia (AL) patients who achieved complete remission following remission induction chemotherapy (RIC) as outpatients, but who did not receive antimicrobials to treat or prevent febrile neutropenia. METHODS: Saliva and stool samples from 9 patients with acute myeloid leukemia, 11 patients with acute lymphoblastic leukemia, and 5 healthy controls were subjected to 16S ribosomal RNA sequencing at baseline and at 3 months following RIC. Only patients who achieved remission at 3 months post-treatment were included. We excluded anyone who used antimicrobials within 2 months of enrollment or at any time during the study period. RESULTS: At baseline, the relative abundances of species of Prevotella maculosa (P=0.001), Megasphaera micronuciformis (P=0.014), Roseburia inulinivorans (P=0.021), and Bacteroides uniformis (P=0.004) in saliva and Prevotella copri (P=0.002) in the stools of controls were significantly higher than in AL patients. Following RIC, the relative abundances of Eubacterium sp. oral clone DO008 (P=0.012), Leptotrichia sp. oral clone IK040 (P=0.002), Oribacterium sp. oral taxon 108 (P=0.029), Megasphaera micronuciformis (P=0.016), TM7 phylum sp. oral clone DR034 (P<0.001), Roseburia inulinivorans (P=0.034), Actinomyces odontolyticus (P=0.014), Leptotrichia buccalis (P=0.005), and Prevotella melaninogenica (P=0.046) in saliva and Lactobacillus fermentum (P=0.046), Coprococcus catus (P=0.050), butyrate-producing bacterium SS3/4 (P=0.013), and Bacteroides coprocola (P=0.027) in the stools of AL patients were significantly greater than in controls. CONCLUSION: Following RIC, several taxa are changed in stool and salvia samples of AL patients. Our results warrant future large-scale multicenter studies to examine whether the microbiota might have an effect on clinical outcomes of AL patients.

Dendritic cells fused with endothelial progenitor cells play immunosuppressive effects on angiogenesis in acute myeloid leukemia mice.

This study aimed to explore role of dendritic cells (DCs) fused with endothelial progenitor cells (EPCs) in inhibiting angiogenesis in acute myeloid leukemia (AML) mice. EPCs were isolated from human AML bone marrow mononuclear cells and fused with DCs, which were then injected back into AML mice. Changes in leukemia cells, micro-vessel density (MVD), early EPC molecular markers vascular endothelial growth factor receptor 2 (VEGFR2/KDR) and CD133 in bone marrow were measured. The results indicated that CD133 and KDR expression in EPCs was significantly higher than in epithelial cells (HUVECs). There were 46.14% ± 8.21% DCs doubly positive for VEGFR2 and CD11c, and it was 8.53% ± 1.27% in co-culture group. Fusion rate of DC/EPCs was 37.61% ± 6.94%, and 35.63% ± 6.09% in DC/ECs group. Growth rate of DC/EPCs was faster than that of EPCs (P<0.05). At 14-20 days after fused cells injection, symptoms gradually decreased. There were a greater number of micro-vessels in bone marrow biopsy sections of AML mice than in normal controls (P<0.05). There was slightly lower MVD in EC/DCs compared with EPC/DCs (P>0.05). Positive expression of CD133 and VEGFR2 in bone marrow biopsies of AML mice was significantly higher than that in control mice (P<0.05). Positive expression of CD133 and VEGFR2 in DC/EC fused cells was significantly lower than that before fusion (P<0.05). In conclusion, DC-EPCs play a certain immunosuppressive effect on angiogenesis in AML mice. Our findings provide experimental data support for the construction of a cell vaccine with anti-angiogenic effect.

Characterization of microRNA expression profiles by deep sequencing of small RNA libraries in leukemia patients from Naxi ethnic.

BACKGROUND: Leukemia is a hematological malignancy characterized by the proliferation of early lymphoid precursors that replaces normal hematopoietic cells of the bone marrow. Nakhi (Naxi) ethnic minorities considered to be an area of low incidence. MicroRNAs (miRNAs) are a class of small noncoding RNAs that regulate the expression of other genes in various biological processes. The purpose of this work is to study the molecular mechanism of miRNAs in the leukemia from Naxi. METHODS: Six leukemia patients (case 2 to case 7) and one healthy person (case 1) from Nakhi (Naxi) ethnic minorities were recruited. Total RNA was extracted from these samples and small RNA deep sequencing was performed. RESULTS: A list of miRNAs (1,392 known and candidate 125 novels) expressed in leukocytes were identified, and many differentially regulated targets involved in several cellular pathways, such as cancer, Rap1 signaling pathway, Ras signaling pathway, and endocytosis. Additionally, quantitative real time-polymerase chain reaction (qRT-PCR) results show that hsa-miR-181b-5p, hsa-miR-181a-3p, hsa-miR-181a-5p, and hsa-miR-342-3p has different expression patterns in different cancer cells, hsa-miR-450a-5p, and hsa-miR-1255a were dysregulated in all leukemia cells. CONCLUSIONS: Several abnormal expressed miRNAs in leukemia patients were identified, the correlation of miRNAs dysregulation and leukemia biology demonstrates that specific miRNA can be potential therapeutic target.

Association of serum adiponectin levels with artherosclerosis and the metabolic syndrome in obese children.

BACKGROUND: The atherosclerotic process starts at an early age and is linked to obesity. However, the exact pathophysiological mechanism is poorly understood. OBJECTIVE: To investigate the relationship between serum adiponectin and metabolic syndrome and early arteriosclerosis. SUBJECTS: 176 obese and 88 normal children. METHODS: Ultrasound measurement was performed to investigate IMT, FMD, carotid artery compliance (CAC). Adiponectin was measured by enzyme-linked immunosorbent assay. RESULTS: Adiponectin levels correlated negatively with obese markers, blood pressure, fasting insulin, high sensitive CRP, HOMA-IR and IMT; marginally positively associated with CAC and HDL-c. The risk of metabolic syndrome increased 3.43 times when adiponectin levels were less than 7060 ng/ml. Heavy obesity, hypertension, low HDL-c, fasting hyperinsulin, High LDL-c and metabolic syndrome percentage were different in three groups according to the cut-off value of adiponectin. CONCLUSIONS: Low adiponectin levels are associated with a high incidence of metabolic syndrome.