[The diagnosis and treatment of esophageal perforation and neck abscess induced by esophageal foreign body]

Objective:To explore the clinical characteristics and treatment methods of esophageal perforation and neck abscess induced by esophageal foreign body. Method:Twenty-six cases with esophageal perforation and neck abscess caused by esophageal foreign body treated in our department were performed surgery under general anesthesia. Result:The foreign bodies were removed via esophagoscope in 24 cases, no foreign bodies were found in 2 cases. Twenty-five case cured and one case was sent to the department of thoracic surgery. Conclusion:For the patients with esophageal perforation and neck abscess, regular perfect preoperative CT scan, timely take out foreign body; meanwhile indwelling nasal-stomach tube, the vacancy of the esophagus, avoid food spillage through the perforation and aggravating infection; adequate antibiotics and nutritional support can improve the cure rate.

EGFR-targeted mAb therapy modulates autophagy in head and neck squamous cell carcinoma through NLRX1-TUFM protein complex

EGFR-targeted therapy in head and neck squamous cell carcinoma (HNSCC) patients frequently results in tumor resistance to treatment. Autophagy is an emerging underlying resistance mechanism, however, the molecular autophagy machinery in HNSCC cells and potential biomarkers of patient response to EGFR-targeted therapy remain insufficiently characterized. Here we show that the EGFR blocking with cetuximab leads to varied autophagic responses, which modulate cancer cell susceptibility to EGFR inhibition. Inhibition of autophagy sensitizes HNSCC cells to EGFR blockade. Importantly, we identify a novel signaling hub centering on the NLRX1-TUFM protein complex, promoting autophagic flux. Defects in the expression of either NLRX1 or TUFM result in compromised autophagy when treated with EGFR inhibitors. As a previously undefined autophagy-promoting mechanism, we found that TUFM serves as a novel anchorage site, recruiting Beclin-1 to mitochondria, promoting its polyubiquitination, and interfering with its interaction with Rubicon. This protein complex is also essential for endoplasmic reticulum (ER) stress signaling induction, possibly as an additional mechanism to promote autophagy. Utilizing tumor specimens from a novel neoadjuvant clinical trial, we show that increased expression of the autophagy adaptor protein, SQSTM1/p62, is associated with poor response to cetuximab therapy. These findings expand our understanding of the components involved in HNSCC autophagy machinery that responds to EGFR inhibitors, and suggest potential combinatorial approaches to enhance its therapeutic efficacy.

Using local multiplicity to improve effect estimation from a hypothesis-generating pharmacogenetics study

We propose a multiple estimation adjustment (MEA) method to correct effect overestimation due to selection bias from a hypothesis-generating study (HGS) in pharmacogenetics. MEA uses a hierarchical Bayesian approach to model individual effect estimates from maximal likelihood estimation (MLE) in a region jointly and shrinks them toward the regional effect. Unlike many methods that model a fixed selection scheme, MEA capitalizes on local multiplicity independent of selection. We compared mean square errors (MSEs) in simulated HGSs from naive MLE, MEA and a conditional likelihood adjustment (CLA) method that model threshold selection bias. We observed that MEA effectively reduced MSE from MLE on null effects with or without selection, and had a clear advantage over CLA on extreme MLE estimates from null effects under lenient threshold selection in small samples, which are common among 'top' associations from a pharmacogenetics HGS.

Expression, purification and antibody preparation of PCV2 Rep and ORF3 proteins

Rep and ORF3 proteins are important functional proteins of porcine circovirus 2 (PCV2). Here, Rep and ORF3 genes were cloned, expressed and used to raise polyclonal antibodies. The result showed the recombinant plasmids of Rep and ORF3 genes constructed in this study were expressed efficiently in the prokaryotic system, and the recombinant proteins had antigenicity and immunogenicity. Furthermore, reactivity and specificity of the antiserums were characterized by western blot and indirect immunofluorescent assays. The results elucidated that polyclonal antiserum prepared with Rep or ORF3 had good reactivity and specificity against PCV2, or the Rep and ORF3 expressed in PK-15 cells, respectively. The Rep protein is promising for PCV2 antibody and vaccine development. These results will be helpful for further studies focusing on pathogenesis of PCV2 and serology diagnostic test or vaccine development against PCV2.

Germ cell-specific expression of Cre recombinase using the VASA promoter in the pig

The Cre–loxP system is a powerful tool for genetic analysis of distinct cell lineages and tissue‐specific gene knockout in animal models. VASA is specifically expressed in reproductive tissues, and is known to play important roles in spermatogenesis and germ‐cell growth. In this study, Cre recombinase transgenic pigs under the control of the VASA promoter were generated by somatic cell nuclear transfer. Germ cell‐specific expression of Cre recombinase in VASA‐Cre transgenic pigs was shown by western blotting and immunohistochemistry. VASA‐Cre transgenic pigs will be a useful tool for germ cell‐specific gene knockout and a disease model for disorders of the reproductive system.

Transcriptional Regulation of JARID1B/KDM5B Histone Demethylase by Ikaros, Histone Deacetylase 1 (HDAC1), and Casein Kinase 2 (CK2) in B-cell Acute Lymphoblastic Leukemia

Impaired function of the Ikaros (IKZF1) protein is associated with the development of high-risk B-cell precursor acute lymphoblastic leukemia (B-ALL). The mechanisms of Ikaros tumor suppressor activity in leukemia are unknown. Ikaros binds to the upstream regulatory elements of its target genes and regulates their transcription via chromatin remodeling. Here, we report that Ikaros represses transcription of the histone H3K4 demethylase, JARID1B (KDM5B). Transcriptional repression of JARID1B is associated with increased global levels of H3K4 trimethylation. Ikaros-mediated repression of JARID1B is dependent on the activity of the histone deacetylase, HDAC1, which binds to the upstream regulatory element of JARID1B in complex with Ikaros. In leukemia, JARID1B is overexpressed, and its inhibition results in cellular growth arrest. Ikaros-mediated repression of JARID1B in leukemia is impaired by pro-oncogenic casein kinase 2 (CK2). Inhibition of CK2 results in increased binding of the Ikaros-HDAC1 complex to the promoter of JARID1B, with increased formation of trimethylated histone H3 lysine 27 and decreased histone H3 Lys-9 acetylation. In cases of high-risk B-ALL that carry deletion of one Ikaros (IKZF1) allele, targeted inhibition of CK2 restores Ikaros binding to the JARID1B promoter and repression of JARID1B. In summary, the presented data suggest a mechanism through which Ikaros and HDAC1 regulate the epigenetic signature in leukemia: via regulation of JARID1B transcription. The presented data identify JARID1B as a novel therapeutic target in B-ALL and provide a rationale for the use of CK2 inhibitors in the treatment of high-risk B-ALL.

Efficient Generation of Myostatin Mutations in Pigs Using the CRISPR/Cas9 System

Genetically modified pigs are increasingly used for biomedical and agricultural applications. The efficient CRISPR/Cas9 gene editing system holds great promise for the generation of gene-targeting pigs without selection marker genes. In this study, we aimed to disrupt the porcine myostatin (MSTN) gene, which functions as a negative regulator of muscle growth. The transfection efficiency of porcine fetal fibroblasts (PFFs) was improved to facilitate the targeting of Cas9/gRNA. We also demonstrated that Cas9/gRNA can induce non-homologous end-joining (NHEJ), long fragment deletions/inversions and homology-directed repair (HDR) at the MSTN locus of PFFs. Single-cell MSTN knockout colonies were used to generate cloned pigs via somatic cell nuclear transfer (SCNT), which resulted in 8 marker-gene-free cloned pigs with biallelic mutations. Some of the piglets showed obvious intermuscular grooves and enlarged tongues, which are characteristic of the double muscling (DM) phenotype. The protein level of MSTN was decreased in the mutant cloned pigs compared with the wild-type controls, and the mRNA levels of MSTN and related signaling pathway factors were also analyzed. Finally, we carefully assessed off-target mutations in the cloned pigs. The gene editing platform used in this study can efficiently generate genetically modified pigs with biological safety.

Fat-1 gene inhibits human oral squamous carcinoma cell proliferation through downregulation of β-catenin signaling pathways

The ω-3 fatty acid desaturase (fat-1) gene encodes the enzyme that converts ω-6 polyunsaturated fatty acids (PUFAs) to ω-3 PUFAs. Numerous studies have suggested that the ratio of ω-6/ω-3 PUFAs has an impact on tumorigenesis. To investigate the biological function of the fat-1 gene in human oral squamous cell carcinoma (OSCC), the fat-1 gene was introduced into OSCC cells by transfection. The uptake of the gene was confirmed by reverse transcription-polymerase chain reaction and analyzed using gas chromatography. The antitumor effects and mechanisms of the fat-1 gene were evaluated by studying cell survival and tumor growth in vitro and in vivo. Gas chromatography results revealed that the cells transfected with the fat-1 gene had a higher ω-3/ω-6 PUFA ratio than cells transfected with the control vector. An MTT and DNA fragmentation assay indicated that the presence of the fat-1 gene in vitro significantly decreased OSCC cell proliferation and significantly increased the rate of apoptosis. Similar antitumor effects of the fat-1 gene were also observed in vivo. Immunohistochemistry analysis confirmed that Tca8113 cell tumors displayed a significant reduction in cell growth and cell survival following the introduction of the fat-1 gene. The current study suggests that the inhibitory effect of the fat-1 gene on tumor growth may be a result of a reduction in the expression of the tumor survival protein β-catenin. The results also support the theory that the ratio of ω-3/ω-6 PUFAs has an impact on OSCC tumor growth. The findings of the study provide notable molecular insight into the theory suggesting that ω-3 PUFAs are an intermediate for the chemoprevention and treatment of human OSCC.

Toxicological effects of benzo[a]pyrene on DNA methylation of whole genome in ICR mice

It has been well known that alterations in DNA methylation - an important regulator of gene transcription - lead to cancer. Therefore a change in the level of DNA methylation of whole genome has been considered as a biomarker of carcinogenesis. Previously, a large number of experimental results in genetic toxicology have showed that benzo[a]pyrene could cause DNA mutation and fragmentation. However, there was little to no studies on alterations in DNA methylation of genome directly result from exposure to benzo[a]pyrene. In this paper, possible mechanisms of alterations in whole genomic DNA methylation by benzo[a]pyrene were investigated using ICR mice after benzo[a]pyrene exposure. The blood, liver, pancreas, skin, lung and bladder of ICR mice were removed and checked after a fixed time interval (6 hours) of benzo[a]pyrene exposure, and whole genomic DNA methylation level was determined by high performance liquid chromatography (HPLC). The results exhibited tissue specificity, that is, the level of whole genomic DNA methylation decreases significantly in blood and liver, rather than pancreas, lung, skin and bladder of ICR mice. This study investigated the direct relationship between aberrant DNA methylation level and benzo[a]pyrene exposure, which might be helpful to clarify the toxicological mechanism of benzo[a]pyrene in epigenetic perspectives.

Valproic Acid Improves Porcine Parthenogenetic Embryo Development Through Transient Remodeling of Histone Modifiers

Background/Aims: Parthenogenetic embryos are useful in many applications, such as being an alternative source of embryonic stem cells that would avoid ethical problems. Aberrance in epigenetic reprogramming is considered the major reason for the developmental failure of parthenogenetic embryos. Many histone deacetylase inhibitors have been shown to improve the reprogramming of stem cells and embryos. Here, the relationship between histone modification and parthenogenetic embryonic development was explored. Methods: Valproic acid (VPA) treatment was applied during the culture of parthenogenetic embryos. The abundance of histone modifiers was examined by immunofluorescence and quantified by Image-pro software. Results: The acH3K9 level in in vitro fertilized embryos was significantly higher than parthenogenetic embryos. VPA treatment improved both the blastocyst formation rate and the acH3K9 level in parthenogenetic embryos. The signal intensities of acH4K5 and H3K4me2 were also enhanced in VPA treated embryos. The H3K27me2 level was decreased in the VPA treated embryos at the 2-cell stage. However, the enhancement in the acH3K9, acH4K5 and H3K4me2 level, or the decrease in the H3K27me2 level disappeared shortly after VPA withdrawal. Conclusion: Optimizing histone modifications for a short time following activation was sufficient to enhance the in vitro development of parthenogenetic embryos.

Inhibition of 3-hydroxy-3-methylglutaryl-coenzyme A reductase increases the expression of interferon-responsive genes

The 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) pathway is an important metabolic route that is present in almost every organism. However, whether HMGCR affects the expression of interferon (IFN)-responsive genes is unclear. In the present study, expression levels of IFN-responsive genes were monitored by real time polymerase chain reaction and enzyme-linked immunosorbent assay. The results showed that expression levels of IFN-responsive genes were significantly increased in HMGCR-downregulated cells and HMGCR inhibitor-treated cells, indicating that inhibition of HMGCR activates the expression of IFN-responsive genes. The result in this study will provide new insight into the role of 3-hydroxy-3-methylglutaryl-coenzyme A reductase in antiviral research.

Transgenic shRNA pigs reduce susceptibility to foot and mouth disease virus infection

Foot-and-mouth disease virus (FMDV) is an economically devastating viral disease leading to a substantial loss to the swine industry worldwide. A novel alternative strategy is to develop pigs that are genetically resistant to infection. Here, we produce transgenic (TG) pigs that constitutively expressed FMDV-specific short interfering RNA (siRNA) derived from small hairpin RNA (shRNA). In vitro challenge of TG fibroblasts showed the shRNA suppressed viral growth. TG and non-TG pigs were challenged by intramuscular injection with 100 LD₅₀ of FMDV. High fever, severe clinical signs of foot-and-mouth disease and typical histopathological changes were observed in all of the non-TG pigs but in none of the high-siRNA pigs. Our results show that TG shRNA can provide a viable tool for producing animals with enhanced resistance to FMDV.

DOI:http://dx.doi.org/10.7554/eLife.06951.001

Foot-and-mouth disease regularly causes serious outbreaks in livestock. The virus that causes the disease can infect cattle, pigs, sheep, goats, and many species of wild animals; the disease is also highly contagious and spreads very quickly and easily. To control the spread of foot-and-mouth disease, farmers must often kill entire herds of animals that have been exposed. Wild animals that can spread the virus may also be killed in an effort to stop the spread of the disease.

Vaccines that protect against foot-and-mouth disease are available and are often used to help prevent the spread of the disease. However, once an outbreak of foot-and-mouth disease begins it may be too late for vaccines to stop its spread. This is because the vaccines can take about a week to provide protection, and by that time an exposed animal may already be very ill.

Previous work conducted in 2010 reported that mice could be genetically engineered to produce short stretches of RNA molecules that can switch off genes from the foot-and-mouth disease virus. Compared with normal mice infected with the foot-and-mouth disease virus, the genetically engineered mice showed little sign of the disease in their bodies. Now, Hu, Qiao, Fu et al.—including some of the researchers involved in the 2010 work—have genetically engineered pigs in the same way. The experiments show that when cells from these pigs are exposed to the foot-and-mouth disease virus in the laboratory, the virus grows much less than normal.

Next, Hu, Qiao, Fu et al. injected genetically engineered pigs and non-genetically engineered pigs with the virus. All of the normal pigs developed severe symptoms very quickly, including the disease's characteristic mouth and foot sores. Additionally, examinations of these pigs' cells showed signs of the disease. But the genetically engineered pigs did not become seriously ill and their cells showed little sign of the disease. Some of the genetically engineered pigs developed a few sores but these sores appeared much later than normal. So far, the results suggest that it may be possible to develop pigs that are resistant to foot-and-mouth disease. Hu, Qiao, Fu et al. will next determine whether or not the genetically engineered pigs can pass the foot-and-mouth virus on to other pigs and livestock.

DOI:http://dx.doi.org/10.7554/eLife.06951.002

Apolipoprotein CIII regulates lipoprotein-associated phospholipase A2 expression via the MAPK and NFκB pathways

Apolipoprotein CIII (apo CIII), a small glycoprotein that binds to the surfaces of certain lipoproteins, is associated with inflammatory and atherogenic responses in vascular cells. Lipoprotein-associated phospholipase A₂ (Lp-PLA₂) has been proposed as an inflammatory biomarker and potential therapeutic target for cardiovascular disease (CVD). Here, we report that apo CIII increases Lp-PLA₂ mRNA and protein levels in dose- and time- dependent manner in human monocytic THP-1 cells, and the increase can be abolished by MAPK and NFκB pathway inhibitors. Lp-PLA₂ inhibitor, 1-linoleoyl glycerol attenuates the inflammation induced by apo CIII. In turn, exogenous Lp-PLA₂ expression upregulates apo CIII and the upregulation can be inhibited by 1-linoleoyl glycerol in HepG2 cells. Moreover, plasma Lp-PLA₂ level is correlated with apo CIII expression in pig liver. In vivo, Lp-PLA₂ expression in monocytes and its activity in serum were significantly increased in human apo CIII transgenic porcine models compared with wild-type pigs. Our results suggest that Lp-PLA₂ and apo CIII expression level is correlated with each other in vitro and in vivo.

PROX1 promotes hepatocellular carcinoma proliferation and sorafenib resistance by enhancing β-catenin expression and nuclear translocation

Aberrant activation of the Wnt/β-catenin pathway is frequent in hepatocellular carcinoma (HCC) and contributes to HCC initiation and progression. This abnormal activation may result from somatic mutations in the genes of the Wnt/β-catenin pathway and/or dysregulation of the Wnt/β-catenin pathway. The mechanism for the latter remains poorly understood. Prospero-related homeobox 1 (PROX1) is a downstream target of the Wnt/β-catenin pathway in human colorectal cancer and elevated PROX1 expression promotes malignant progression. However, the Wnt/β-catenin pathway does not regulate PROX1 expression in the liver and HCC cells. Here we report that PROX1 promotes HCC cell proliferation in vitro and tumor growth in HCC xenograft mice. PROX1 and β-catenin levels are positively correlated in tumor tissues as well as in cultured HCC cells. PROX1 can upregulate β-catenin transcription by stimulating the β-catenin promoter and enhance the nuclear translocation of β-catenin in HCC cells, which leads to the activation of the Wnt/β-catenin pathway. Moreover, we show that increase in PROX1 expression renders HCC cells more resistant to sorafenib treatment, which is the standard therapy for advanced HCC. Overall, we have pinpointed PROX1 as a critical factor activating the Wnt/β-catenin pathway in HCC, which promotes HCC proliferation and sorafenib resistance.

Isoform-specific imprinting of the MEST gene in porcine parthenogenetic fetuses

Aberrant expression of imprinted genes is the main reason for developmental retardation in mammalian parthenogenetic fetuses. Mesoderm specific transcript (MEST) is a maternally imprinted gene that is linked to cancer and is necessary for normal early embryonic development. Tissue and isoform-specific imprinting of MEST have been identified in humans and mice, but have not yet been identified in pigs. In this study, the three isoforms of porcine MEST were identified using the GenBank and Ensembl sequence databases. Then, we determined MEST isoform-specific mRNA expression and methylation levels by quantitative real-time PCR (qRT-PCR) and bisulfite sequencing PCR analysis (BSP) between porcine parthenogenetic (PA) and control (Con) fetuses, respectively. Altogether, our results demonstrated that the expression of MEST-1A and MEST-1B has no evident differences between PA and Con groups; however, there is no expression of MEST-1C in PA fetuses. In addition, the results of BSP showed that the hypermethylation of exon 1c of MEST-1C was observed in PA samples. Thus, we suggested that MEST-1C was isoform-specific imprinting, which may be contributed to differential methylation status of exon 1c in porcine fetuses.

Protein phosphatase 1 (PP1) and Casein Kinase II (CK2) regulate Ikaros-mediated repression of TdT in thymocytes and T-cell leukemia

BACKGROUND

Ikaros is a DNA-binding protein that acts as master-regulator of hematopoiesis and a tumor suppressor. In thymocytes and T-cell leukemia, Ikaros negatively regulates transcription of terminal deoxynucleotide transferase (TdT), a key protein in lymphocyte differentiation. The signaling pathways that regulate Ikaros-mediated repression of TdT are unknown. Our previous work identified Casein Kinase II (CK2) and Protein Phosphatase 1 (PP1) as regulators of Ikaros DNA binding activity. Here, we investigated the role of PP1 and CK2 in regulating Ikaros-mediated control of TdT expression.

PROCEDURES

Ikaros phosphomimetic and phosphoresistant mutants and specific CK2 and PP1 inhibitors were used in combination with quantitative chromatin immunoprecipitation (qChIP) and quantitative reverse transcriptase-PCR (q RT-PCR) assays to evaluate the role of CK2 and PP1 in regulating the ability of Ikaros to bind the TdT promoter and to regulate TdT expression.

RESULTS

We demonstrate that phosphorylation of Ikaros by pro-oncogenic CK2 decreases Ikaros binding to the promoter of the TdT gene and reduces the ability of Ikaros to repress TdT expression during thymocyte differentiation. CK2 inhibition and PP1 activity restore Ikaros DNA-binding affinity toward the TdT promoter, as well as Ikaros-mediated transcriptional repression of TdT in primary thymocytes and in leukemia.

CONCLUSION

These data establish that PP1 and CK2 signal transduction pathways regulate Ikaros-mediated repression of TdT in thymocytes and leukemia. These findings reveal that PP1 and CK2 have opposing effects on Ikaros-mediated repression of TdT and establish novel roles for PP1 and CK2 signaling in thymocyte differentiation and leukemia.

Aberrant expression of Xist in aborted porcine fetuses derived from somatic cell nuclear transfer embryos

Cloned pigs generated by somatic cell nuclear transfer (SCNT) show a greater ratio of early abortion during mid-gestation than normal controls. X-linked genes have been demonstrated to be important for the development of cloned embryos. To determine the relationship between the expression of X-linked genes and abortion of cloned porcine fetuses, the expression of X-linked genes were investigated by quantitative real-time polymerase chain reaction (q-PCR) and the methylation status of Xist DMR was performed by bisulfate-specific PCR (BSP). q-PCR analysis indicated that there was aberrant expression of X-linked genes, especially the upregulated expression of Xist in both female and male aborted fetuses compared to control fetuses. Results of BSP suggested that hypomethylation of Xist occurred in aborted fetuses, whether male or female. These results suggest that the abnormal expression of Xist may be associated with the abortion of fetuses derived from somatic cell nuclear transfer embryos.