ABSTRACT
BACKGROUND:Unlike linear RNAs,circular RNAs (circRNAs) are a novel type of RNA which can form covalently closed circles and are highly expressed in eukaryotic transcriptomes.In the plenitude of naturally occurring RNAs,circRNAs and their biological role are underestimated for years.Recent studies have discovered thousands of endogenous circRNAs in mammalian cells.OBJECTIVE:To review the formation,properties,and functions of circRNAs,and their potential significance in diseases.METHODS:A computer-based search for literature in CNKI and PubMed databases published from January 2000 to December 2016 was performed using the keywords of "circRNA,miRNA,function,mechanism" in English and Chinese,respectively.Finally,62 eligible articles were included for analysis.RESULTS AND CONCLUSION:CircRNAs are largely generated from exonic or intronic sequences,and reverse complementary sequences or RNA-binding proteins are necessary for circRNA biogenesis.A majority of circRNAs that are conserved across specie are stable and resistant to RNaseR,and often exhibit tissue/developmental-stage-specific expression.Recent research has revealed that circRNAs can function as microRNA sponges,regulators of splicing and transcription,and modifiers of parental gene expression.Emerging evidence indicates that circRNAs might play important roles in atherosclerotic vascular diseases,neurological disorders,prion diseases and cancer;exhibit aberrant expression in colorectal cancer;and serve as diagnostic or predictive biomarkers of some diseases.Similar to microRNAs and long noncoding RNAs,circRNAs are arousing general interest in the field of RNA and widely participate in the life process.
ABSTRACT
Great challenges remain in the noninvasive luminescence imaging analysis of tumor-targeting dynamics of nanocarriers in living animals which is of significance for the development of anti-cancer nanomedicine. In this work, luminescent nanoparticles Eu(tta)3bpt@SMA (dav = 15 nm), which exhibited good water dispersion stability and high yields of red Eu-luminescence under near-infrared two-photon excitation, were prepared by a modified microfluidic mixing method in the absence of surfactants. Tumor-targeting agents, Arg-Gly-Asp-D-Phe-Lys (cRGD) polypeptide or transferrin (Tf), were then anchored on the nanoparticle surfaces to form the desired nanocarriers Eu@SMA-RGD or Eu@SMA-Tf. The tumor-targeting processes of the prepared nanocarriers in intact living mice were analyzed on a home-built two-photon excitation time-resolved (TPE-TR) imaging apparatus having a wide view filed. The TPE-TR strategy could effectively suppress the interference from biological autofluorescence, which allowed the targeted domains to be visualized with a high signal-to-noise ratio. It was found that the tumor-tissue trapping efficacy of Eu@SMA-RGD was much higher than that of Eu@SMA-Tf, and the desorption process from the tumor tissues of Eu@SMA-RGD was slower than that of Eu@SMA-Tf. The methods developed in this work pave a way to investigate the in vivo tumor-targeting dynamics of nanocarriers by noninvasive luminescence imaging of living animals.
Subject(s)
Europium/chemistry , Liver Neoplasms/diagnostic imaging , Luminescent Agents/chemistry , Luminescent Measurements/methods , Maleates/chemistry , Nanoparticles/chemistry , Optical Imaging/methods , Polystyrenes/chemistry , Animals , Hep G2 Cells , Humans , Mice, Nude , Nanoparticles/ultrastructure , Peptides, Cyclic/chemistry , Photons , Transferrin/chemistryABSTRACT
The aim of this study was to investigate the in vitro effect of interleukin-24 (IL-24) on apoptosis of bone marrow mononuclear cells (BMMNC) in children with acute leukemia. Every group of acute lymphocytic leukemia (ALL) and acute myeloid leukemia (ANLL) had 20 children who did not receive any therapy. The bone marrow was taken from patients and controls, the MNC were isolated from bone marrow, DNA was detected by glucose electrophoresis. Apoptosis of BMMNC was assayed by flow cytometry with propidium iodine staining. RT-PCR was used to detect the expression level of bcl-2, caspase-3 mRNA, and to analyze the effect of IL-24 on them. The results showed that the IL-24 induced apoptosis of BMMNC in children with acute leukemia. After acute leukemia BMMNC were exposed to IL-24 for 48 hours, DNA ladder fragment appeared, and the apoptotic rate of the group treated with IL-24 of 50 ng/ml was obviously higher than that of the control group (0 ng/ml). IL-24 decreased the bcl-2 mRNA expression level, enhanced caspase-3 mRNA expression level of BMMNC from AL patients. It is concluded that the IL-24 can induce apoptosis of AL BMMNC in vitro, which may be due to decreasing of bcl-2 mRNA level and enhancing of caspase-3 mRNA level.
Subject(s)
Adolescent , Child , Child, Preschool , Female , Humans , Male , Acute Disease , Apoptosis , Bone Marrow Cells , Cell Biology , Caspase 3 , Metabolism , Interleukins , Pharmacology , Leukemia , Pathology , Proto-Oncogene Proteins c-bcl-2 , MetabolismABSTRACT
Objective To investigate children′s myelodysplastic hematopoietic cells reaction to interleukin (IL)-15.Methods CD 34 + cells in bone marrow from 18 myelodysplast syndrome(MDS) patients were purified by an immunomagnetic beads sorting system. Apoptosis of hematopoietic precursors was assayed by propidium iodine staining and flow cytometric analysis.Results On 8th cultured day,when IL-15 concentration was between 0-100 ng/ml,it could suppress apoptosis of hematopoietic cells in MDS patients in a dose-and- time dependent manner. IL-15 in study group significanthy lower than that of control group.Conclusion IL-15 may partly suppress apoptosis of hematopoietic cells in MDS patients.
