Truncated C-terminus of fibrillin-1 induces Marfanoid-progeroid-lipodystrophy (MPL) syndrome in rabbit

Various clinical differences have been observed between patients with the FBN1 gene mutation and those with the classical Marfan phenotype. Although FBN1 knockout (KO) or dominant-negative mutant mice are widely used as an animal model for Marfan syndrome (MFS), these mice cannot recapitulate the genotype/phenotype relationship of Marfanoid-progeroid-lipodystrophy (MPL) syndrome, which is caused by a mutation in the C-terminus of fibrillin-1, the penultimate exon of the FBN1 gene. Here, we describe the generation of a rabbit MPL model with C-terminal truncation of fibrillin-1 using a CRISPR/Cas9 system. FBN1 heterozygous (FBN1 Het) rabbits faithfully recapitulated the phenotypes of MFS, including muscle wasting and impaired connective tissue, ocular syndrome and aortic dilation. Moreover, skin symptoms, lipodystrophy, growth retardation and dysglycemia were also seen in these FBN1 Het rabbits, and have not been reported in other animal models. In conclusion, this novel rabbit model mimics the histopathological changes and functional defects of MPL syndrome, and could become a valuable model for studies of pathogenesis and drug screening for MPL syndrome.

Summary: A novel genetically engineered rabbit model of MPL syndrome, generated by CRISPR/Cas9-mediated mutation of FBN1, mimics the histopathological changes and functional defects of MPL syndrome seen in the clinic.

Analysis of angiogenesis biomarkers for ramucirumab efficacy in patients with metastatic colorectal cancer from RAISE, a global, randomized, double-blind, phase III study

Background

The phase III RAISE trial (NCT01183780) demonstrated that the vascular endothelial growth factor (VEGF) receptor (VEGFR)-2 binding monoclonal antibody ramucirumab plus 5-fluororuracil, leucovorin, and irinotecan (FOLFIRI) significantly improved overall survival (OS) and progression-free survival (PFS) compared with placebo + FOLFIRI as second-line metastatic colorectal cancer (mCRC) treatment. To identify patients who benefit the most from VEGFR-2 blockade, the RAISE trial design included a prospective and comprehensive biomarker program that assessed the association of biomarkers with ramucirumab efficacy outcomes.

Patients and methods

Plasma and tumor tissue collection was mandatory. Overall, 1072 patients were randomized 1 : 1 to the addition of ramucirumab or placebo to FOLFIRI chemotherapy. Patients were then randomized 1 : 2, for the biomarker program, to marker exploratory (ME) and marker confirmatory (MC) groups. Analyses were carried out using exploratory assays to assess the correlations of baseline marker levels [VEGF-C, VEGF-D, sVEGFR-1, sVEGFR-2, sVEGFR-3 (plasma), and VEGFR-2 (tumor tissue)] with clinical outcomes. Cox regression analyses were carried out for each candidate biomarker with stratification factor adjustment.

Results

Biomarker results were available from >80% (n = 894) of patients. Analysis of the ME subset determined a VEGF-D level of 115 pg/ml was appropriate for high/low subgroup analyses. Evaluation of the combined ME + MC populations found that the median OS in the ramucirumab + FOLFIRI arm compared with placebo + FOLFIRI showed an improvement of 2.4 months in the high VEGF-D subgroup [13.9 months (95% CI 12.5-15.6) versus 11.5 months (95% CI 10.1-12.4), respectively], and a decrease of 0.5 month in the low VEGF-D subgroup [12.6 months (95% CI 10.7-14.0) versus 13.1 months (95% CI 11.8-17.0), respectively]. PFS results were consistent with OS. No trends were evident with the other antiangiogenic candidate biomarkers.

Conclusions

The RAISE biomarker program identified VEGF-D as a potential predictive biomarker for ramucirumab efficacy in second-line mCRC. Development of an assay appropriate for testing in clinical practice is currently ongoing.

Clinical trials registration

NCT01183780.

[Combined T2-weighted and diffusion-weighted MR imaging for staging of rectal cancers]

Objective: To compare the diagnostic value of T2 weighted imaging (T2WI), diffusion-weighted imaging (DWI), and T2WI+ DWI magnetic resonance imaging (MRI) for staging of rectal cancers for improving the accuracy of tumor staging. Methods: From January 2011 to December 2013, 120 cases of rectal cancers proved by colonoscopy without receiving any anti-tumor treatment were enrolled retrospectively. The MRI data for these patients were divided into three groups, ie., T2WI, DWI and T2WI+ DWI, for evaluating the tumor stages. The results were compared with histopathologic findings. The sensitivity and specificity were calculated and compared with chi-square test. The nodal staging was predicted by using T2WI+ DWI. Results: The accuracy for prediction of tumor staging was 83.3%, 65.0% and 92.5% for T2WI, DWI, and T2WI+ DWI respectively. The specificity for evaluating T1 and T2 stage, and the sensitivity for evaluating T3 by DWI was significantly lower than those using T2WI and T2WI+ DWI in rectal cancers. The sensitivity for evaluation of T2 by DWI was lower than that using T2WI+ DWI (63.0% vs. 88.9%). The sensitivity for evaluation T2 and specificity for T3 by T2WI+ DWI was higher than thouse using T2WI only (88.9% vs. 51.9%, 94.0% vs. 72.0%). The accuracy for prediction of nodal staging by using T2WI+ DWI was 62.1% (72/116). Conclusions: T2WI is the key sequence for staging of rectal cancers. Although the diagnostic accuracy was not good by using DWI alone, the combination of T2WI and DWI can improve the accuracy significantly for tumor staging in rectal cancers, whereas the nodal staging was still a hard task for radiologists.

[Measurement reproducibility of parameters derived from introvoxel incoherent motion diffusion-weighted MRI imaging of rectal cancer]

Objective: To study the measurement reproducibility of parameters derived from introvoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI)-MRI of rectal cancer between- and within- radiologists. Methods: Clinical data of 34 patients with rectal cancer were prospective analyzed. Conventional MRI sequences, IVIM DWI-MRI with sixteen b values and dynamic contrast enhancement (DCE)-MRI sequences of rectum were acquired by GE 3.0-T MRI imager. The IVIM sequence images with b value=1000 sec/mm(2) were selected to measure the maximum axial section of tumor by a radiologist with 15 year-experiences in gastrointestinal cancer imaging.Two radiologists (radiologist 1 and radiologist 2 with 2 and 10 years of experience in gastrointestinal cancer imaging, respectively) independently draw a freehand region of interest (ROI) that contained the largest available tumor area on the selected section. Monoexponential apparent diffusion coefficient (ADC) and biexponential IVIM metrics maps and IVIM parameters were generated automatically by the software. The repeated measurement was performed at an interval of one week. The average values of each measurement were used for statistical analysis. ADC values and IVIM parameters obtained between- and within- radiologists were analyzed by Wilcoxon signed-rank test. Intraclass correlation coefficients (ICC) and Bland-Altaman plots were used to analyze the parameter reproducibility of two measurements between- and within- radiologists. Results: The first and second measured ADC (×10(-3)mm(2)/s), true diffusivity (D, ×10(-3)mm(2)/s), false diffusivity (D(*,) mm(2)/s) and perfusion fraction (f, %) by radiologist 1 were 0.997, 0.692, 0.043, 34.6 and 0.993, 0.691, 0.038, 32.8, respectively. The first and second measured ADC (×10(-3)mm(2)/s), D (×10(-3)mm(2)/s), D(*) (mm(2)/s), f (%) by radiologist 2 were 0.987, 0.651, 0.046, 32.8 and 0.996, 0.689、0.041, 32.7, respectively. No statistically significant differences were observed in ADC and IVIM parameters obtained between- and within- radiologists (P>0.05). The ADC values and the f values of two times were significantly correlated between- and within- radiologists. The D values were significantly correlated within a radiologist, and the correlation of D(*) values within a radiologist was significantly higher than that between radiologists. The 95% limits of agreement (LoA) of ADC values and f values were smaller than those of D values and D(*) values between- and within- radiologists. The 95% LoA of ADC values was the least, while that of D(*) values varied most.The 95% LoA of f values and D values kept steady within a radiologist, and 95% LoA of f values was slightly smaller than that of D values. The 95% LoA of IVIM parameters (ADC, D, f, D(*) values) within radiologists 2 were better than those within radiologist 1. Conclusions: The reproducibilities of ADC and f values are the best, while the reproducibility of D(*) values is relatively poorer in rectal cancer. Measurement reproducibility of parameters derived from IVIM may be improved by increasing radiologists' experiences in drawing ROI.

Characterization and comparative analysis of immunoglobulin lambda chain diversity in a neonatal porcine model

To elucidate how antigen exposure and selection shape the porcine antibody repertoires, we investigated the immunoglobulin lambda light chain (IGL) gene repertoires of the binary cross-bred (Yorkshire×Landrace) pig at different developmental stages, pre-suckle neonate (0days), wean piglet (35days) and growing pig (75days) under normal farming conditions. Immunoglobulin lambda light transcript (IGLV-J-C) clones of the peripheral blood mononuclear cells (PBMCs) from these different developmental stages were assessed for IGL combination, junction and sequence diversity. Previous research has revealed that IGLV8 plays a major role in immunity during the early fetus stage and that IGLV3 accounts for 30% of the neonatal IGLV repertoires. Here, we found that the antibody profile exhibited salient features at different stages. The usage of the IGLV3-3 subclass gradually decreased during development, in contrast, the utilization of IGLV8 (IGLV8-10, IGLV8-13 and IGLV8-18), which started in the fetal stage, has increased in the growing stage. Moreover, the junction diversity, as measured by the IGLV hypervariable complementarity determining region 3 (CDR3L) lengths, was constant during the different stages. The complete junction mutation ratio clearly increased in the growing pig compared to that in the younger pig. Our data provide new insights into the postnatal porcine IGLV repertoires maturation which can lay the foundation for porcine antibody gene research.

CRISPR/Cas9-mediated knockout of myostatin in Chinese indigenous Erhualian pigs

CRISPR/Cas9 has emerged as one of the most popular genome editing tools due to its simple design and high efficiency in multiple species. Myostatin (MSTN) negatively regulates skeletal muscle growth and mutations in myostatin cause double-muscled phenotype in various animals. Here, we generated myostatin mutation in Erhualian pigs using a combination of CRISPR/Cas9 and somatic cell nuclear transfer. The protein level of myostatin precursor decreased dramatically in mutant cloned piglets. Unlike myostatin knockout Landrace, which often encountered health issues and died shortly after birth, Erhualian pigs harboring homozygous mutations were viable. Moreover, myostatin knockout Erhualian pigs exhibited partial double-muscled phenotype such as prominent muscular protrusion, wider back and hip compared with wild-type piglets. Genome editing in Chinese indigenous pig breeds thus holds great promise not only for improving growth performance, but also for protecting endangered genetic resources.

microRNA-10b enhances pancreatic cancer cell invasion by suppressing TIP30 expression and promoting EGF and TGF-β actions

This corrects the article DOI: 10.1038/onc.2013.405.

Optimization of a CRISPR/Cas9-mediated Knock-in Strategy at the Porcine Rosa26 Locus in Porcine Foetal Fibroblasts

Genetically modified pigs have important roles in agriculture and biomedicine. However, genome-specific knock-in techniques in pigs are still in their infancy and optimal strategies have not been extensively investigated. In this study, we performed electroporation to introduce a targeting donor vector (a non-linearized vector that did not contain a promoter or selectable marker) into Porcine Foetal Fibroblasts (PFFs) along with a CRISPR/Cas9 vector. After optimization, the efficiency of the EGFP site-specific knock-in could reach up to 29.6% at the pRosa26 locus in PFFs. Next, we used the EGFP reporter PFFs to address two key conditions in the process of achieving transgenic pigs, the limiting dilution method and the strategy to evaluate the safety and feasibility of the knock-in locus. This study demonstrates that we establish an efficient procedures for the exogenous gene knock-in technique and creates a platform to efficiently generate promoter-less and selectable marker-free transgenic PFFs through the CRISPR/Cas9 system. This study should contribute to the generation of promoter-less and selectable marker-free transgenic pigs and it may provide insights into sophisticated site-specific genome engineering techniques for additional species.

IWP2 impairs the development of porcine somatic cell nuclear transfer embryos via Wnt signaling pathway inactivation

Wnt signaling is critical in embryonic development and post-embryonic tissue homeostasis. The aim of the present study was to evaluate the expression levels of canonical Wnt signaling genes in porcine somatic cell nuclear transfer (SCNT) embryos. Quantitative polymerase chain reaction analysis was performed in porcine SCNT embryos, and the results indicated that the temporal expression patterns of canonical signaling genes were similar between in vivo and SCNT embryos from the 2-cell to the blastocyst stage. In addition, aberrant expression in a small number of Wnt signaling genes in SCNT embryos was identified. IWP2, an inhibitor of Wnt processing, was applied to the culture of SCNT embryos. The Wnt signaling pathway in the SCNT blastocysts may be inactivated via IWP2 treatment, reflecting the low expression levels of c-Myc and peroxisome proliferator-activated receptor δ. Furthermore, blastocyst hatching was damaged by IWP2 treatment. These findings indicate that the canonical Wnt signaling pathway is important for SCNT embryo development.

[Texture analysis based on contrast-enhanced MRI can predict treatment response to neoadjuvant chemotherapy of breast cancer]

Objective: To investigate whether texture analysis based on contrast-enhanced MRI can predict pathological complete response of locally advanced breast cancer undergoing neoadjuvant chemotherapy(NAC). Methods: Forty-seven patients with breast cancer undergone neoadjuvant chemotherapy from January 2015 to February 2016 were divided into pathological complete response (pCR) group or non-pathological complete response (non-pCR) group based on surgical pathology. Their parameters of texture analysis based on MRI before neoadjuvant chemotherapy and after 2 cycles of treatment were analyzed. Parameters(Energy, Entropy, Inertia, Correlation, Inverse Difference Moment)before and after 2 cycles of NAC between pCR and non-pCR groups were compared using Student t or Wilcoxon rank sum test. The diagnostic performance of different parameters was judged by the receiver-operating characteristic (ROC) curve analysis. Results: The post-NAC value was significantly different from that of pre-NAC (all P<0.05). Pre-treatment parameters (Energy, Entropy, Inertia, Correlation, Inverse Difference Moment) were 78.58×10(-5)(55.64×10(-5), 135.23×10(-5)), 10.06 ± 1.02, 7 993.91±2 428.10, (4.76±0.99) ×10(-5) and (18.10±4.13) ×10(-3) in pCR group, and 76.84×10(-5) (48.68×10(-5), 154.15×10(-5)), 10.28±1.26, 7 184.77 (4 938.03, 9 974.04), (5.21±2.01) ×10(-5) and (17.68±5.87) ×10(-3) in non-pCR group. No significant difference was found between both groups. (P>0.05 for all). At the end of the second cycle of NAC, parameters(Energy, Entropy, Inertia, Correlation, Inverse Difference Moment) were (542.11±361.04) ×10(-5,) 7.95±1.28, 16 765.08±97 06.56, (0.43±0.07) ×10(-5,) and (12.18±9.82) ×10(-3) in pCR group, and 133.00×10(-5) (79.80×10(-5,) 239.00×10(-5)), 9.29±1.46, 7 916.64(6 418.89, 10 934.40), (0.38±0.08) ×10(-5) and (14.80±5.06) ×10(-3) in non-pCR group. At the end of the second cycle of NAC, there was significant difference in the parameters (Energy, Entropy, Inertia, Correlation) and Δparameters (ΔEnergy, ΔEntropy, ΔInertia, ΔInverse Difference Moment) between both groups (P<0.05 for all). The area under curve (AUC) of post-treatment ΔEntropy was 0.81, which was the largest one among parameters. Sensitivity of ΔEntropy for predicting pCR was 75.0% and specificity was 85.7%, respectively. Conclusion: Texture analysis based on dynamic contrast-enhanced MRI can predict early treatment response in primary breast cancer.

Single particle labeling of RNA virus in live cells

Real-time and visual tracking of viral infection is crucial for elucidating the infectious and pathogenesis mechanisms. To track the virus successfully, an efficient labeling method is necessary. In this review, we first discuss the practical labeling techniques for virus tracking in live cells. We then describe the current knowledge of interactions between RNA viruses (especially influenza viruses, immunodeficiency viruses, and Flaviviruses) and host cellular structures, obtained using single particle labeling techniques combined with real-time fluorescence microscopy. Single particle labeling provides an easy system for understanding the RNA virus life cycle.

Efficient Generation of Orthologous Point Mutations in Pigs via CRISPR-assisted ssODN-mediated Homology-directed Repair

Precise genome editing in livestock is of great value for the fundamental investigation of disease modeling. However, genetically modified pigs carrying subtle point mutations were still seldom reported despite the rapid development of programmable endonucleases. Here, we attempt to investigate single-stranded oligonucleotides (ssODN) mediated knockin by introducing two orthologous pathogenic mutations, p.E693G for Alzheimer's disease and p.G2019S for Parkinson's disease, into porcine APP and LRRK2 loci, respectively. Desirable homology-directed repair (HDR) efficiency was achieved in porcine fetal fibroblasts (PFFs) by optimizing the dosage and length of ssODN templates. Interestingly, incomplete HDR alleles harboring partial point mutations were observed in single-cell colonies, which indicate the complex mechanism of ssODN-mediated HDR. The effect of mutation-to-cut distance on incorporation rate was further analyzed by deep sequencing. We demonstrated that a mutation-to-cut distance of 11 bp resulted in a remarkable difference in HDR efficiency between two point mutations. Finally, we successfully obtained one cloned piglet harboring the orthologous p.C313Y mutation at the MSTN locus via somatic cell nuclear transfer (SCNT). Our proof-of-concept study demonstrated efficient ssODN-mediated incorporation of pathogenic point mutations in porcine somatic cells, thus facilitating further development of disease modeling and genetic breeding in pigs.

Pseudorabies virus can escape from CRISPR-Cas9-mediated inhibition

The CRISPR-Cas9 system is a newly developed genome-engineering tool used to inhibit virus infection by targeting the conserved regions of the viral genomic DNA. In the present study, we constructed a cell line stably expressing Cas9 endonuclease and sgRNA targeting the conserved UL30 gene of pseudorabies virus (PRV). During the PRV infection, the CRISPR-Cas9 system was efficient in cleaving the UL30 gene in each passage. However, deletions and insertions occurred at low passages, while substitutions were frequently observed at high passages. Furthermore, copy numbers and virus titers of PRV were significantly increased in a passage-dependent manner, indicating that viral genomic replication and assembly were more effective at the high passages than at low passages. These results demonstrated that PRV could escape from CRISPR-Cas9-mediated inhibition. Therefore, whether the CRISPR-Cas9 system is suitable for antiviral application should be considered and carefully verified.

Classical swine fever virus replicated poorly in cells from MxA transgenic pigs

Background

In addition to their value as livestock, pigs are susceptible to classical swine fever virus (CSFV) and can serve as reservoirs for CSFV, allowing it to develop into an epizootic. CSFV, a pestivirus of the Flaviviridae family, has a single-stranded RNA genome. Recent research has indicated that the human MxA protein inhibits the life cycles of certain RNA viruses, such as members of the Bunyaviridae family, the Flaviviridae family and others.

Results

To produce pigs with antiviral protection against CSFV, transgenic pigs expressing human MxA were generated by nuclear transplantation. Cells from three MxA transgenic piglets were used to investigate in vitro antiviral activity of MxA aganist CSFV, and the results of in vitro indirect immunofluorescence assays, virus titration and real-time PCR indicated that the MxA transgenic pig has an antiviral capacity against CSFV.

Conclusions

Transgene with human MxA on pigs is feasible. High levels of MxA expression do inhibit CSFV in vitro at early time points post-infection at 60-96dpi.

Barriers for Deriving Transgene-Free Pig iPS Cells with Episomal Vectors

To date no authentic embryonic stem cell (ESC) line or germline-competent-induced pluripotent stem cell (iPSC) line has been established for large animals. Despite this fact, there is an impression in the field that large animal ESCs or iPSCs are as good as mouse counterparts. Clarification of this issue is important for a healthy advancement of the stem cell field. Elucidation of the causes of this failure in obtaining high quality iPSCs/ESCs may offer essential clues for eventual establishment of authentic ESCs for large animals including humans. To this end, we first generated porcine iPSCs using nonintegrating replicating episomal plasmids. Although these porcine iPSCs met most pluripotency criteria, they could neither generate cloned piglets through nuclear transfer, nor contribute to later stage chimeras through morula injections or aggregations. We found that the reprogramming genes in iPSCs could not be removed even under negative selection, indicating they are required to maintain self-renewal. The persistent expression of these genes in porcine iPSCs in turn caused differentiation defects in vivo. Therefore, incomplete reprogramming manifested by a reliance on sustained expression of exogenous-reprogramming factors appears to be the main reason for the inability of porcine iPSCs to form iPSC-derived piglets.

Effects of Aluminum Exposure on the Bone Stimulatory Growth Factors in Rats

Aluminum (Al) is considered to be a potentially toxic metal and inhibits bone formation. Transforming growth factor β1 (TGF-β1) and bone morphogenetic protein 2 (BMP-2) play an important role in regulating the bone formation. Therefore, this study aimed to investigate the effects of Al on the TGF-β1 and BMP-2 in rats. In this study, Wistar rats were randomly divided into Al-treated group and control group. The Al-treated rats were provided with drinking water containing 100 mg/L AlCl3, and the control rats were given distilled water for 30, 60, and 90 days, respectively. Ten rats were sacrificed in each group every 30 days. The Al-treated rats showed lower body weight and higher serum and bone levels of Al compared with the control rats. The expression levels of TGF-β1 and BMP-2 were also significantly decreased in the Al-treated rats. Serum levels of bone gamma-carboxyglutamic acid protein (BGP), carboxy-terminal propeptide of type I procollagen (PICP), and bone alkaline phosphatase (B-ALP) were markedly lower in the Al-treated groups than in the control group. These results indicate that Al inhibits the expression of TGF-β1 and BMP-2 in bone, which inhibits the activity of osteoblasts and reduces the synthesis of BGP, B-ALP, and type I collagen, thereby inhibiting bone formation.

Rapid and sensitive LC-MS/MS method for the determination of auraptene in rat plasma and its application in a pharmacokinetic and bioavailability study in rats

A simple, sensitive and specific liquid chromatography-tandem mass spectrometry method was developed and validated for the determination of auraptene, a constituent isolated from Fructus aurantii with potential to combat Alzheimer's disease, in rat plasma. Rat plasma samples were pretreated by protein precipitation with methanol. The analytes were separated by a Waters Sun Fire C18 column (50 mm x 2 mm, 5 μm) and eluted with 1:1000 methanol and formic acid/water (v/v) mobile phase with a flow rate of 0.5 mL/min. Multiple reaction monitoring was used to monitor the transition of the deprotonated auraptene molecule with an m/z of 299.3 [M+H](+), to the product ion with an m/z of 162.9 [M+H](+). Progesterone, with an m/z of 315.2→ 96.9 was used as an internal standard. The limits of detection and of quantification of auraptene in the rat plasma were 1 and 5 ng/mL, respectively. The method was linear in the concentration range of 20- 2000 ng/mL with coefficient correlation of 0.9956. After auraptene (100 mg/kg, p.o.) administration, the maximum plasma concentration and the time taken to reach maximum concentration were 1719.5 ± 384.3 g/mL and 108.0 ± 25.3 min, respectively. The elimination half-life was 108.0 ± 25.3 for auraptene (100 mg/kg, p.o.) and 3.0 ± 0 min for auraptene (2 mg/kg, i.v.). The oral bioavailability was about 8.5%.

Induction of Germ Cell-like Cells from Porcine Induced Pluripotent Stem Cells

The ability to generate germ cells from pluripotent stem cells (PSCs) is valuable for human regenerative medicine and animal breeding. Germ cell-like cells (GCLCs) have been differentiated from mouse and human PSCs, but not from porcine PSCs, which are considered an ideal model for stem cell applications. Here, we developed a defined culture system for the induction of primordial germ cell-like cells (PGCLCs) from porcine induced PSCs (piPSCs). The identity of the PGCLCs was characterized by observing cell morphology, detecting germ cell marker gene expression and evaluating epigenetic properties. PGCLCs could further differentiate into spermatogonial stem cell-like cells (SSCLCs) in vitro. Importantly, meiosis occurred during SSCLC induction. Xenotransplantation of GCLCs into seminiferous tubules of infertile immunodeficient mice resulted in immunohistochemically identifiable germ cells in vivo. Overall, our study provides a feasible strategy for directing piPSCs to the germ cell fate and lays a foundation for exploring germ cell development mechanisms.

Chimerism in piglets developed from aggregated cloned embryos

Porcine chimeras are valuable in the study of pluripotency, embryogenesis and development. It would be meaningful to generate chimeric piglets from somatic cell nuclear transfer embryos. In this study, two cell lines expressing the fluorescent markers enhanced green fluorescent protein (EGFP) and tdTomato were used as donor cells to produce reconstructed embryos. Chimeric embryos were generated by aggregating two EGFP‐cell derived embryos with two tdTomato‐cell derived embryos at the 4‐cell stage, and embryo transfer was performed when the aggregated embryos developed into blastocysts. Live porcine chimeras were successfully born and chimerism was observed by their skin color, gene integration, microsatellite loci composition and fluorescent protein expression. The chimeric piglets were largely composed of EGFP‐expressing cells, and this phenomenon was possibly due to the hyper‐methylation of the promoter of the tdTomato gene. In addition, the expression levels of tumorigenicity‐related genes were altered after tdTomato transfection in bladder cancer cells. The results show that chimeric pigs can be produced by aggregating cloned embryos and that the developmental capability of the cloned embryo in the subsequent chimeric development could be affected by the growth characteristics of its donor cell.

Knockdown of linc-UFC1 suppresses proliferation and induces apoptosis of colorectal cancer

Long intergenic noncoding RNAs (lincRNAs) have important roles in biological functions, molecular mechanisms and prognostic values in colorectal cancer (CRC). In this context, the roles of linc-UFC1 remain to be elucidated. In this study, linc-UFC1 was overexpressed in CRC patient tissues and positively correlated with tumor grade, N stage and M stage. Inhibition of linc-UFC1 resulted in cell proliferation inhibition and G1 cell cycle arrest, which was mediated by cyclin D1, CDK4, Rb and phosphorylated Rb. In addition, inhibition of linc-UFC1 induced cell apoptosis through the intrinsic apoptosis signaling pathway, as evidenced by the activation of caspase-9 and caspase-3. An investigation of the signaling pathway revealed that the effects on proliferation and apoptosis following linc-UFC1 knockdown were mediated by suppression of β-catenin and activation of phosphorylated P38. Furthermore, the P38 inhibitor SB203580 could attenuate the apoptotic effect achieved by linc-UFC1 knockdown, confirming the involvement of P38 signaling in the induced apoptosis. Taken together, linc-UFC1 might have a critical role in pro-proliferation and anti-apoptosis in CRC by regulating the cell cycle, intrinsic apoptosis, and β-catenin and P38 signaling. Thus, linc-UFC1 could be a potential therapeutic target and novel molecular biomarker for CRC.

N-3 polyunsaturated fatty acids attenuates triglyceride and inflammatory factors level in hfat-1 transgenic pigs

BACKGROUND

The consumption of n-3 polyunsaturated fatty acids (PUFAs) is important to human health, especially in cases of cardiovascular disease. Although beneficial effects of n-3 PUFAs have been observed in a number of studies, the mechanisms involved in these effects have yet to be discovered.

METHODS

We generated hfat-1 transgenic pigs with traditional somatic cell nuclear transfer (SCNT) technology. The fatty acid composition in ear tissue of pigs were detected with gas chromatography. The cholesterol, triglycerides (TAG) and inflammation mediators in circulation were investigated.

RESULTS

The hfat-1 transgenic pigs were developed which accumulate high levels of n-3 PUFAs than wild-types pigs. Gas chromatography results demonstrated that the total n-3 PUFAs in the ear tissues of the transgenic founders were 2-fold higher than the wild-type pigs. A lipid analysis demonstrated that the levels of TAG in the transgenic pigs were decreased significantly. The basal levels of the inflammation mediators tumor necrosis factor-α (TNF-α), monocyte chemoattractant protein-1 (MCP-1) and interleukin-6 (IL-6) in transgenic pigs were inhibited markedly compared with the wild-type pigs.

CONCLUSIONS

These results suggest that n-3 PUFAs accumulation in vivo may have beneficial effects on vascular and hfat-1 transgenic pigs may be a useful tool for investigating the involved mechanisms.