piRNA-823 contributes to tumorigenesis by regulating de novo DNA methylation and angiogenesis in multiple myeloma

Aberrant DNA hypermethylation contributes to myelomagenesis by silencing tumor-suppressor genes. Recently, a few reports have suggested that a novel class of small non-coding RNAs, called Piwi-interacting RNAs (piRNAs), may be involved in the epigenetic regulation of cancer. In this study, for the first time we provided evidence that the expression of piRNA-823 was upregulated in multiple myeloma (MM) patients and cell lines, and positively correlated with clinical stage. Silencing piRNA-823 in MM cells induced deregulation of cell cycle regulators and apoptosis-related proteins expression, accompanied by inhibition of tumorigenicity in vitro and in vivo. Moreover, piRNA-823 was directly relevant to de novo DNA methyltransferases, DNMT3A and 3B, in primary CD138(+) MM cells. The inhibited expression of piRNA-823 in MM cells resulted in marked reduction of DNMT3A and 3B at both mRNA and protein levels, which in turn led to decrease in global DNA methylation and reexpression of methylation-silenced tumor suppressor, p16(INK4A). In addition, piRNA-823 abrogation in MM cells induced reduction of vascular endothelial growth factor secretion, with consequent decreased proangiogenic activity. Altogether, these data support an oncogenic role of piRNA-823 in the biology of MM, providing a rational for the development of piRNA-targeted therapeutic strategies in MM.

DanQi Pill protects against heart failure through the arachidonic acid metabolism pathway by attenuating different cyclooxygenases and leukotrienes B4

Background

Chinese herbal formulae are composed of complex components and produce comprehensive pharmacological effects. Unlike chemical drugs that have only one clear single target, the components of Chinese herbal formulae have multiple channels and targets. How to discover the pharmacological targets of Chinese herbal formulae and their underlying molecular mechanism are still under investigation.

Methods

DanQi pill (DQP), which is one of the widely prescribed traditional Chinese medicines, is applied as an example drug. In this study, we used the drug target prediction model (DrugCIPHER-CS) to examine the underlying molecular mechanism of DQP, followed by experimental validation.

Results

A novel therapeutic effect pattern of DQP was identified. After determining the compounds in DQP, we used DrugCIPHER-CS to predict their potential targets. These potential targets were significantly enriched in well-known cardiovascular disease-related pathways. For example, the biological processes of neuroactive ligand–receptor interaction, calcium-signaling pathway, and aminoacyl–tRNA biosynthesis were involved. A new and significant pathway, arachidonic acid (AA) metabolism, was also identified in this study. This predicted pathway alteration was validated with an animal model of heart failure (HF). Results show that DQP had effect both on thromboxane B2 (TXB2) and Prostaglandin I2 (PGI2) in different patterns. It can down-regulate the TXB2 and up-regulate the PGI2 in diverse way. Remarkably, it also had effect on cyclooxygenase (COX)-1 and COX2 by suppressing their levels, which may be the critical and novel mechanism of cardiacprotective efficacy for DQP. Furthermore, leukotrienes B4 (LTB4) receptor, another key molecule of AA metabolism which finally mediated gastrotoxic leukotrienes, was also reduced by DQP.

Conclusions

The combination of drug target prediction and experimental validation provides new insights into the complicated mechanism of DQP.

The beam diagnostic instruments in Beijing radioactive ion-beam facilities isotope separator on-line

The beam diagnostic instruments for Beijing Radioactive Ion-beam Facilities Isotope Separator On-Line are introduced [B. Q. Cui, Z. H. Peng, Y. J. Ma, R. G. Ma, B. Tang, T. Zhang, and W. S. Jiang, Nucl. Instrum. Methods 266, 4113 (2008); T. J. Zhang, X. L. Guan, and B. Q. Cui, in Proceedings of APAC 2004, Gyeongju, Korea, 2004, http://www.jacow.org, p. 267]. For low intensity ion beam [30-300 keV/1 pA-10 μA], the beam profile monitor, the emittance measurement unit, and the analyzing slit will be installed. For the primary proton beam [100 MeV/200 μA], the beam profile scanner will be installed. For identification of the nuclide, a beam identification unit will be installed. The details of prototype of the beam diagnostic units and some experiment results will be described in this article.

Experimental results of a dual-beam ion source for 200 keV ion implanter

A dual beam ion source for 200 keV ion implanter aimed to produce 200 keV H2 (+) and He(+) beams simultaneously has been developed. Not suitable to use the analyzing magnet, the purity of beam extracted from the source becomes important to the performance of implanter. The performance of ion source was measured. The results of experiments show that the materials of inlet tube of ion source, the time of arc ionization in ion source, and the amount of gas flow have significant influence on the purity of beam. The measures by using copper as inlet tube material, long time of arc ionization, and increasing the inlet of gas flow could effectively reduce the impurity of beam. And the method using the gas mass flow controller to adjust the proportion of H2 (+) and He(+) is feasible.

An ion source module for the Beijing Radioactive Ion-beam Facility

An ion source module is developed for Beijing Radioactive Ion-beam Facility. The ion source module is designed to meet the requirements of remote handling. The connection and disconnection of the electricity, cooling and vacuum between the module and peripheral units can be executed without on-site manual work. The primary test of the target ion source has been carried out and a Li(+) beam has been extracted. Details of the ion source module and its primary test results are described.

The development of the high intensity electron cyclotron resonance ion source at China Institute of Atomic Energy

High-current microwave ion source has been under development over 15 years for accelerator driven sub-critical system research at China Institute of Atomic Energy, and the beam intensity higher than 140 mA proton beam is produced by this ion source with long lifetime and high reliability. The emittance of high intensity continue-wave and pulse beam is measured on a test-bench in the laboratory. Based on the good performance of this proton ion source, a new 120 mA deuterium ion source is proposed for a high intensity neutron generator. The ion source details and status will be presented.

Roles of Wnt/β-catenin signaling in the gastric cancer stem cells proliferation and salinomycin treatment

The Wnt1 protein, a secreted ligand that activates Wnt signaling pathways, contributes to the self-renewal of cancer stem cells (CSCs) and thus may be a major determinant of tumor progression and chemoresistance. In a series of gastric cancer specimens, we found strong correlations among Wnt1 expression, CD44 expression, and the grade of gastric cancer. Stable overexpression of Wnt1 increased AGS gastric cancer cells' proliferation rate and spheroids formation, which expressed CSC surface markers Oct4 and CD44. Subcutaneous injection of nude mice with Wnt1-overexpressing AGS cells resulted in larger tumors than injection of control AGS cells. Salinomycin, an antitumor agent, significantly reduced the volume of tumor caused by Wnt1-overexpressing AGS cells in vivo. This is achieved by inhibiting the proliferation of CD44+Oct4+ CSC subpopulation, at least partly through the suppression of Wnt1 and β-catenin expression. Taken together, activation of Wnt1 signaling accelerates the proliferation of gastric CSCs, whereas salinomycin acts to inhibit gastric tumor growth by suppressing Wnt signaling in CSCs. These results suggest that Wnt signaling might have a critical role in the self-renewal of gastric CSCs, and salinomycin targeting Wnt signaling may have important clinical applications in gastric cancer therapy.

SPG35 contributes to the second common subtype of AR-HSP in China: frequency analysis and functional characterization of FA2H gene mutations

Hereditary spastic paraplegias (HSPs) encompass a clinically and genetically heterogeneous group of neurodegenerative disorders. Recently, mutations in fatty acid 2-hydroxylase gene (FA2H) have been identified responsible for HSPs type 35 (SPG35). This study aims to define the contribution of FA2H to Chinese autosomal recessive HSP (AR-HSP) patients and provide insights into the enzymatic functions of the novel mutations. Direct sequencing of FA2H was conducted in 31 AR-HSP families and 55 sporadic cases without SPG11, SPG15, SPG5 and SPG7 gene mutations. Enzymatic activity of the mutated proteins was further examined. Three novel mutations were found in two Chinese families, including two compound heterozygous mutations (c.388C>T/p.L130F and c.506+6C>G) and one homozygous mutation (c.230T>G/p.L77R). The c.506+6C>G splice-site mutation led to the deletion of exon 3. Measurement of enzymatic functions revealed a significant reduction in the enzymatic activity of FA2H associated with p.L130F and p.L77R. Overall, our data widens the spectrum of the mutations on FA2H, and functional analyses indicate that these mutations severely impair the enzymatic activity of FA2H. Furthermore, frequency analysis shows that SPG35 is the second most common subtype of AR-HSP in China.

Fuzi-Lizhong pill compensates hypothyroid-hypothermia via ghrelin release

ETHNOPHARMACOLOGICAL RELEVANCE

Fuzi-Lizhong pill (FLZ) is a traditional Chinese medicine for treating patients with Spleen Yang deficient syndrome. Ghrelin, a peptide with 28 amino acid residues, plays multiple roles in thermogenesis. This study aims to explore FLZ regulating ghrelin to compensate hypothermia in rats with hypothyroid and indigestion.

MATERIALS AND METHODS

In litter-matched rats, hypothermia was developed with both thyroidectomy at d1 and interscapular brown adipose (IBA) removal at d42, indigestion was induced with both high fat diet and fasting-feeding cycle from d56; the littermates with hypothermia and indigestion were administrated with FLZ from d70. Adaptive thermogenesis, thyroid hormones, metabolites, ghrelin dynamics were measured at d98.

RESULTS

The results showed that plasma ghrelin levels were inversely correlated with the gastric ghrelin levels and adaptive thermogenesis in rats undergone both thyroidectomy and IBA removal. Fatty diet and FLZ enhanced the increase of plasma ghrelin of hypothyroid rats. These were supported by the changes of plasma thyroid related hormones, plasma metabolites, gastric ghrelin mRNA and protein, and the effects of fatty diet or FLZ.

CONCLUSIONS

Our results suggest that more ghrelin release compensate chronic hypothermia in rats with both hypothyroidism and indigestion. It could explain the mechanisms of FLZ in relieving chronic hypothermia.

cDNA cloning and characterization of two trehalases from Spodoptera litura (Lepidoptera; Noctuidade)

The oriental leafworm moth, Spodoptera litura, is a major agricultural pest in southeast Asia and nearby Pacific regions. Two distinct trehalases have been identified in insects: soluble trehalase (Treh1) and membrane-bound trehalase (Treh2), although there is currently no information on these genes in S. litura. To characterize the distribution and function of treh, cDNAs of Treh proteins were cloned from S. litura. SpoliTreh1 cDNA has an open reading frame of 1758 nucleotides, which encodes a protein of 585 amino acids, with a predicted mass of approximately 67.07 kDa and an isoelectric point of 4.86. SpoliTreh2 cDNA has an open reading frame of 2325 nucleotides, encoding a protein of 645 amino acids, a mass of approximately 73.62 kDa, and an isoelectric point of 5.90. Northern blotting analysis revealed that SpoliTreh1 transcripts are in the midgut, fat body, tracheae, and epidermis, but not in the brain and Malpighian tubules of S. litura larvae, whereas SpoliTreh2 transcripts were found in all 6 tissues. SpoliTreh1 transcripts were highly expressed in the fat body of the pre-pupal stage, and SpoliTreh2 transcripts were highly expressed in the fat body of 3-day-old larvae of the 6th instar and during the 1st 6 days of the pupal stage, except the 2nd day. Both SpoliTreh1 and SpoliTreh2 were highly expressed in third-instar larvae.

308 Tet1 PLAYS IMPORTANT ROLES IN MAINTAINING CHARACTERIZATIONS OF PORCINE INDUCED PLURIPOTENT STEM CELLS

It was recently found that the ten-eleven-translocation (TET) family of Fe(II) and 2-oxoglutarate-dependent enzymes (Tet1/2/3) can oxidize 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC), and thus promotes active demethylation of genomes. Tet1 is highly expressed in mouse embryonic stem cells (mESC) and has been demonstrated to involve in mESC maintenance. Here we used small interference RNA (siRNA) to transiently knockdown expression of Tet1 in porcine induced pluripotent stem cells (iPSC) in order to identify its functions. The fetal fibroblasts were isolated from a 30-day-old porcine fetus and induced into iPSC with defined transcription factors, namely Oct-4, Sox-2, Klf-4, and C-myc. The colonies appeared on Day 12 and were picked up on Day 14. These colonies had normal ES-like morphology and alkaline phosphatase activity. Specifically, they were positively stained for pluripotency-specific markers, including Oct4, Sox2, Nanog, Rex1, and SSEA1. When cultured in vitro, the cells formed embryoid bodies (EB), and all 3 germ layer markers (endoderm: AFP, alphaAT; mesoderm: BMP4, Enolase; ectoderm: GFAP, Neurod) were detected positively in EB. For siRNA transfections, iPSC from the colonies were transfected with 40 pmol of siRNA and 2 µL of Lipofectamine 2000 in 1 well of a 24-well plate. After transfection, iPSC were subjected to fluorescence-activated cell sorting to determine the fraction of FAM-positive cells in order to confirm transfection efficiency; the percentage of positive cells reached 48 ± 4.96. We observed obvious knockdown of Tet1 after short-term transfection of siRNA, and the knockdown efficiency was confirmed using qRT-PCR and immunofluorescence staining. Notably, knockdown of Tet1 resulted in morphological abnormality and loss of undifferentiated state of porcine iPSC. However, no obvious morphological changes were observed in the negative control (transfected with nonsense-siRNA), positive control (transfected with GAPDH-siRNA), or mock control (transfected with DEPC-treated water). To gain insight into the molecular mechanism underlying the self-renewal defect, we analysed the effects of Tet1 knockdown on the expression of key stem cell factors and differentiation markers of different embryonic layers using qRT-PCR. We found that knockdown of Tet1 resulted in downregulated expression of pluripotency-related genes, such as Lefty-2, Klf-2, and Sox-2 (the expression ratios of post-transfection to pre-transfection were 0.31 ± 0.21, 0.48 ± 0.072, and 0.65 ± 0.046, respectively), and upregulated expression of differentiation-related genes, including Pitx-2, Hand-1, Gata-6, and Lef-1 (the expression ratios of post-transfection to pre-transfection were 4.35 ± 1.36, 2.56 ± 0.68, 2.91 ± 1.47, and 2.33 ± 1.11, respectively). However, Oct-4, C-myc, Klf-4, and Nanog were not downregulated (the expression ratios of post-transfection to pre-transfection were 0.91 ± 0.15, 1.12 ± 0.26, 1.15 ± 0.21, and 1.08 ± 0.08, respectively). Taken together, Tet1 plays important roles in porcine iPSC self-renewal and characterization maintenance. This study was financed by National Basic Research Program of China (NO.2009CB941001).

Novel PRRT2 mutations in paroxysmal dyskinesia patients with variant inheritance and phenotypes

Paroxysmal dyskinesias (PDs) are a group of episodic movement disorders with marked variability in clinical manifestation and potential association with epilepsy. PRRT2 has been identified as a causative gene for PDs, but the phenotypes and inheritance patterns of PRRT2 mutations need further clarification. In this study, 10 familial and 21 sporadic cases with PDs and PDs-related phenotypes were collected. Genomic DNA was screened for PRRT2 mutations by direct sequencing. Seven PRRT2 mutations were identified in nine (90.0%) familial cases and in six (28.6%) sporadic cases. Five mutations are novel: two missense mutations (c.647C>G/p.Pro216Arg and c.872C>T/p.Ala291Val) and three truncating mutations (c.117delA/p.Val41TyrfsX49, c.510dupT/p.Leu171SerfsX3 and c.579dupA/p.Glu194ArgfsX6). Autosomal dominant inheritance with incomplete penetrance was observed in most of the familial cases. In the sporadic cases, inheritance was heterogeneous including recessive inheritance with compound heterozygous mutations, inherited mutations with incomplete parental penetrance and de novo mutation. Variant phenotypes associated with PRRT2 mutations, found in 36.0% of the affected cases, included febrile convulsions, epilepsy, infantile non-convulsive seizures (INCS) and nocturnal convulsions (NC). All patients with INCS or NC, not reported previously, displayed abnormalities on electroencephalogram (EEG). No EEG abnormalities were recorded in patients with classical infantile convulsions and paroxysmal choreoathetosis (ICCA)/paroxysmal kinesigenic dyskinesia (PKD). Our study further confirms that PRRT2 mutations are the most common cause of familial PDs, displaying both dominant and recessive inheritance. Epilepsy may occasionally occur in ICCA/PKD patients with PRRT2 mutations. Variant phenotypes INCS or NC differ from classical ICCA/PKD clinically and electroencephalographically. They have some similarities with, but not identical to epilepsy, possibly represent an overlap between ICCA/PKD and epilepsy.

Knock-down of USP22 by small interfering RNA interference inhibits HepG2 cell proliferation and induces cell cycle arrest

The Ubiquitin--specific protease 22 (USP22) is a new putative cancer stem cell marker, which plays a significant role in tumorigenesis and cell--cycle progression. However, little is known about the impact of USP22 knock--down on the growth of human hepatoma cell lines. In this study, elevated expression of USP22 was observed in the human HepG2 hepatic cancer cell line compared to the normal human hepatocyte Chang liver cell line. Subsequently, we used siRNA specifically suppressing expression of USP22 and observed that the knock--down of USP22 could effectively induce cell cycle arrest and inhibit HepG2 cell proliferation. Furthermore, our results showed that USP22 deletion caused down--regulation of cyclin D2 expression and up--regulation of p15 and p21 expression. Collectively, Our findings indicate that USP22 may be responsible for HepG2 cell growth and USP22 regulates the cell cycle via the c--Myc/cyclin D2 pathway and down--regulating p15 and p21 expression in HepG2 cell.