HIV-1 viral protein R downregulates Ebp1 and stabilizes p53 in glioblastoma U87MG cells

PURPOSE

HIV-1 viral protein R (Vpr) inhibits cell growth and induces apoptosis in a wide range of cancers. However, the mechanism by which Vpr induces cell cycle arrest and apoptosis in GBM cell lines is unclear. The present work was taken to detect the proteins interacted with Vpr in U87MG cells.

METHODS

We analyzed the differential expression of proteins between glioblastoma cell U87MG treated with Ad-Vpr and untreated by 2-DE. We used antibody array analysis to analyze the common molecules in the apoptosis of U87MG induced by Vpr.

RESULTS

We analyzed the differential expression of proteins between U87MG cell treated with Ad-Vpr and untreated, and found that proteins related to DNA damage repair or different apoptosis pathways were involved in the G2 arrest and apoptosis mediated by Vpr. In addition, proliferation-associated protein 2G4 (PA2G4), also known as Ebp1, was down-regulated and p53 was up-regulated in U87MG cells treated with Ad-Vpr.

CONCLUSIONS

Our data suggest that Vpr may inhibit Ebp1 to stabilize p53, which in turn leads to G2 arrest and apoptosis in U87MG cells.

High prevalence of vitamin D insufficiency in pregnant women working indoors and residing in Guiyang, China

BACKGROUND/AIM

To assess the status of 25-hydroxyvitamin D [25(OH)D] in pregnant women in their second and third trimesters, who reside and work indoors in Guiyang, China.

SUBJECTS AND METHODS

A total of 311 pregnant women in their 12th to 40th gestational week were engaged in employment located indoors in the urban area of Guiyang and completed a questionnaire on living habits. Levels of serum 25(OH)D were measured from fasting venous blood by liquid chromatography-mass spectrometry (LC-MS/MS). Levels of 25(OH)D were classified as vitamin D deficient [25(OH)D<20 ng/ml], insufficient [20 ng/ml≤25(OH)D<30 ng/ml], or sufficient [25(OH)D≥30 ng/ml].

RESULTS

The mean serum level of 25(OH)D was 14.69±6.81 ng/ml. Vitamin D deficiency, insufficiency and sufficiency were found in 260 (83.6%), 39 (12.5%), and 12 (3.9%) women, respectively. The mean level of 25(OH)D in the third trimester was significantly higher than in the second trimester (p<0.001). The mean 25(OH)D level in summer (June, July, August) was significantly higher than in the other seasons (p<0.001). The 25(OH)D level in pregnant women compliant with pre-natal calcium or multivitamin supplements was higher than in those not taking supplements (p<0.001).

CONCLUSIONS

These results suggest that pregnant women residing in Guiyang urban area and working indoors are at high risk of vitamin D insufficiency, particularly during spring, winter, and autumn, regardless of use of pre-natal calcium and multivitamins. Appropriate vitamin D supplementation is necessary to improve maternal vitamin D nutrition.

Gossypol and an HMT G9a inhibitor act in synergy to induce cell death in pancreatic cancer cells

The histone methyltransferase G9a is overexpressed in a variety of cancer types, including pancreatic adenocarcinoma, and promotes tumor invasiveness and metastasis. We recently reported the discovery of BRD4770, a small-molecule inhibitor of G9a that induces senescence in PANC-1 cells. We observed that the cytotoxic effects of BRD4770 were dependent on genetic background, with cell lines lacking functional p53 being relatively resistant to compound treatment. To understand the mechanism of genetic selectivity, we used two complementary screening approaches to identify enhancers of BRD4770. The natural product and putative BH3 mimetic gossypol enhanced the cytotoxicity of BRD4770 in a synergistic manner in p53-mutant PANC-1 cells but not in immortalized non-tumorigenic pancreatic cells. The combination of gossypol and BRD4770 increased LC3-II levels and the autophagosome number in PANC-1 cells, and the compound combination appears to act in a BNIP3 (B-cell lymphoma 2 19-kDa interacting protein)-dependent manner, suggesting that these compounds act together to induce autophagy-related cell death in pancreatic cancer cells.

Growth of large-scale vertically aligned GaN nanowires and their heterostructures with high uniformity on SiO(x) by catalyst-free molecular beam epitaxy

The catalyst-free molecular beam epitaxial growth of GaN nanowires and their heterostructures on a SiOx template is studied in detail. It was found that by optimizing the growth temperature, highly uniform and vertically aligned GaN nanowires and InGaN/GaN heterostructures with excellent optical properties can be obtained on a SiOx template in a large-scale. This work provides an entirely new avenue for GaN nanowire based optoelectronic devices.

NFAT5 represses canonical Wnt signaling via inhibition of β-catenin acetylation and participates in regulating intestinal cell differentiation

The intestinal mucosa undergoes a continual process of proliferation, differentiation, and apoptosis, which is regulated by multiple signaling pathways. The Wnt/β-catenin pathway has a critical role in this process. Previously, we have shown that the calcineurin-dependent nuclear factor of activated T cell (NFAT) is involved in the regulation of intestinal cell differentiation, as noted by the alteration of brush-border enzyme intestinal alkaline phosphatase (IAP) activity. Here, we show that calcineurin-independent NFAT5 interacts with β-catenin to repress Wnt signaling. We found that overexpression of NFAT5 inhibits, whereas knockdown of NFAT5 increases, TOPflash reporter activity and the expression of Wnt/β-catenin target genes, suggesting that NFAT5 inhibits Wnt signaling. In addition, we demonstrated that NFAT5 directly interacts with the C-terminal transactivation domain (TAD) of β-catenin, inhibits CBP interaction with β-catenin, and inhibits CBP-mediated β-catenin acetylation. Moreover, NFAT5 is expressed in the mucosa of human intestine, with the most pronounced staining in the most differentiated region near the epithelial surface. Knockdown of NFAT5 attenuated sodium butyrate (NaBT)-mediated induction of IAP and sucrase activities; overexpression of NFAT5 induced IAP promoter activity. In summary, we provide evidence showing that NFAT5 is a regulator of Wnt signaling. Importantly, our results suggest that NFAT5 regulation of intestinal cell differentiation may be through inhibition of Wnt/β-catenin signaling.

Globular adiponectin elicits neuroprotection by inhibiting NADPH oxidase-mediated oxidative damage in ischemic stroke

Recent studies indicate that adiponectin can attenuate cerebral ischemic lesions via its functional area located in the C-terminal globular domain, which is called globular adiponectin (gAD). However, the mechanisms underlying this action remain unclear. In this study, we investigated the antioxidant properties of gAD during cerebral ischemia. Adult male C57BL/6 mice received an intracerebral injection of gAD with or without tetrabromocinnamic acid (TBCA, a NADPH oxidase activator). Mice were subjected to middle cerebral artery occlusion (MCAO) after gAD injection. Infarct volume, neurological function, the activity of antioxidant enzymes (superoxide dismutase [SOD], catalase), the content of malondialdehyde (MDA), and the expression of Bax, Bcl-2, cleaved caspase-3 and NADPH oxidase 2 (NOX2) were examined at 24h after MCAO. Infarct volume was attenuated in gAD-transduced mice when compared with mice in the MCAO group, with significant improvement in neurological function. In addition, neuronal apoptosis was attenuated, along with the expression of Bax/Bcl-2 and cleaved caspase 3. Furthermore, the activities of SOD and catalase increased, and the content of MDA reduced. However, TBCA blocked the effect of gAD on cerebral protection and its antioxidant abilities. Taken together, these results demonstrate that the neuroprotective action of gAD may result from the promotion of antioxidant capacity by inhibiting the NOX2 signaling system.

Bioinformatics analyses combined microarray identify the desregulated microRNAs in lung cancer

BACKGROUND

MicroRNAs (miRNAs) play an important role in the regulation of cell growth, differentiation, apoptosis, and carcinogenesis. Deregulated miRNAs are found in blood cells of cancer patients recently.

AIM

This study aims to screen the differentially expressed miRNAs (DE-miRNAs) which could discriminate lung cancers from non-cancerous lung tissues as well as molecular signatures that differ in tumor histology.

MATERIALS AND METHODS

miRNA expression profiles of GSE17681 was downloaded from Gene Expression Omnibus database. Three test methods were used to identify DE-miRNAs between lung cancer tissue and healthy controls. Target genes of DE-miRNAs were retrieved from three databases and mapped to KEGG to investigate their roles in lung cancer. Further, a protein-protein interaction (PPI) network was constructed used STRING and Cytoscape.

RESULTS

A total of 17 DE-miRNAs were identified. Among them, hsa-miR-339-5p draw specific attention. Pathway analysis revealed that target genes of RASSF1 and KRAS play roles as oncogene or tumor suppressor gene in the progression of lung cancer. Besides, Target genes of RASSF1 and ERBB4 formed a module in the PPI network. Functional analysis suggested biological process of response to hypoxia was significantly enriched.

CONCLUSIONS

hsa-miR-339-5p play important role in the regulation of lung cancer and it may be potential to be used as biomarker to predict lung cancer progression.

BaP-induced DNA damage initiated p53-independent necroptosis via the mitochondrial pathway involving Bax and Bcl-2

Benzo(a)pyrene (BaP), a typical environmental carcinogen, can induce cell death both by protein 53 or tumor protein 53 (p53)-independent and -dependent pathways. However, little is known about the molecular mechanisms of p53-independent pathways in BaP-induced cell death. In this study, cells with different genetic background (including p53-proficient human fetal lung fibroblast cell lines (MRC-5), p53-deficient human non-small-cell lung carcinoma cell lines (H1299), and p53-knockdown cell lines (MRC-5 p53−/−)) were used to establish models of BaP-induced cell death. The results showed that BaP (8, 16, 32, and 64 μM) induced necroptotic cell death in the cell lines. The necroptotic cell death and DNA damage were concurrently observed. In the three cell lines, at 24 h after treatment, BaP (8–64 μM) upregulated expressions of BAX, BCL-2, and cleaved caspase-3 proteins, but not their messenger RNA levels. The findings suggested that BaP-induced necroptosis was modulated by the p53-independent pathway, which was related to the induction of BAX, decreased expression of BCL-2, and activation of caspase-3.

Humoral autoimmune response to IGF2 mRNA-binding protein (IMP2/p62) and its tissue-specific expression in colon cancer

To understand the autoimmune response and immunogenicity of a tumour-associated antigen (TAA) and IGF2 mRNA-binding protein (IMP2/62) in colon cancer, autoantibody to this TAA was evaluated by enzyme-linked immunosorbent assay (ELISA), Western blotting and indirect immunofluorescence assay in sera from patients with colon cancer. Immunohistochemistry (IHC) study with colon cancer tissues was also performed to analyse protein expression of IMP2/p62. The result has showed that there has a relatively higher frequency of autoantibody response to IMP2/p62 in colon cancer (23.4%, 15/64) compared to patients with colonic adenomas (4.8%, 2/42) and normal individuals (2.9%, 1/34). Of 64 colon cancer tissue specimens examined, 48 tissues (75.0%, 48/64) expressed p62, while normal colon tissues did not show any expression of p62 (0/34). The positive rate of antinuclear antibody (ANA) in colon cancer was 82.8% (53/64), which is significantly higher than that in patients with colonic adenomas (21.4%, 9/42) and normal individuals (17.6%, 6/34). The data suggest that the combinational detection of anti-p62 autoantibody and ANA is of significance in diagnosing colon cancer and monitoring the prognosis of the disease.

Efficacy and safety of short-term administration of recombinant human atrial natriuretic peptide (rhANP) for congestive heart failure: a phase II, multicentre randomized controlled dose-finding study

WHAT IS KNOWN AND OBJECTIVE

Although the long-term infusion of ANP has proved effective to treat heart failure, no published randomized controlled study has been reported to confirm the efficacy of the short-term ANP infusion in congestive heart failure (CHF) patients. This study was designed to assess the efficacy and safety of short-term infusion of recombinant human atrial natriuretic peptide (rhANP) in CHF patients.

METHODS

A total of 48 patients with CHF were enrolled and randomized into four groups, treated with standard therapy or rhANP (0·05, 0·1 or 0·2 μg/kg/min) for 1-hour infusion in addition to standard therapy. The hemodynamics were assessed for 12 h by Swan-Ganz catheter.

RESULTS AND DISCUSSION

The effect of the 0·05 μg/kg/min rhANP dose group on CO was modest and transient. The 0·2 μg/kg/min rhANP dose group tended to be associated with better effect on SV, CO and dyspnoea improvement, but modest effect on PCWP and more adverse events probably attributed to the study drug. However, the 0·1 μg/kg/min rhANP infusion was well tolerated and effective both on PCWP decrease (maximum:-9·46 ± 5·81 mmHg compared with baseline (P = 0·0002) and -6·75 mmHg compared with standard therapy, the 95% confidential interval [-13·43, -0·06 mmHg] at 1 h) and CO increase (maximum: 1·02 ± 1·43 L/min [P = 0·0308] at 1 h).

WHAT IS NEW AND CONCLUSION

In this small-sample study, 1-hour infusion of rhANP produced beneficial hemodynamic effects in CHF patients compared with standard therapy, and it was well tolerated. 0·1 μg/kg/min may be the optimum dose for short-term rhANP infusion to treat CHF for the further large sample trial before clinical application.

A one-step molecular biology method for simple and rapid detection of grass carp Ctenopharyngodon idella reovirus (GCRV) HZ08 strain

Six reverse-transcription loop-mediated isothermal amplification (RT-LAMP) primers designed against conserved regions of segment 6 (s6) gene were used for the detection of grass carp Ctenopharyngodon idella reovirus (GCRV) HZ08 subtype. The entire amplification could be completed within 40 min at 62·3° C. The RT-LAMP showed higher sensitivity than reverse-transcription polymerase chain reaction (RT-PCR). The RNA detection limit was 10 copies µl⁻¹ for RT-LAMP assay and 100 copies µl⁻¹ for conventional RT-PCR. In specificity tests, no cross-reactivity was detected in other viruses from common aquatic animals. In addition, the reaction results can be visualized by using calcein fluorescent dye. Furthermore, a total of 86 samples were tested by RT-LAMP, RT-PCR and virus isolation. The results demonstrated that all 54 specimens identified as positive by virus isolation were also positive when detected by RT-LAMP. Seven out of 54 samples, however, were misidentified by RT-PCR. The RT-LAMP method is more accurate than conventional RT-PCR. The results indicate that RT-LAMP has potential as a simple and rapid diagnosis technique for the detection of GCRV HZ08 subtype infection.