Enterotoxin-related genes PPFIA4 and SCN3B promote colorectal cancer development and progression.

To identify the role of enterotoxin-related genes in colorectal cancer (CRC) development and progression. Upregulated differentially expressed genes shared by three out of five Gene Expression Omnibus (GEO) data sets were included to screen the key enterotoxin-induced oncogenes (EIOGs) according to criteria oncogene definition, enrichment, and protein-protein interaction (PPI) network analysis, followed by prognosis survival, immune infiltration, and protential drugs analyses was performed via integration of RNA-sequencing data and The Cancer Genome Atlas-derived clinical profiles. We screened nine common key EIOGs from at least three GEO data sets. A Cox proportional hazards regression models verified that more alive cases, decreased overall survival, and highest 4-year survival prediction in CRC patients with high-risk score. Protein tyrosine phosphatase receptor type F polypeptide-interacting protein alpha-4 (PPFIA4), STY11, SCN3B, and SPTBN5 were shared in the same PPI network. Immune infiltration results showed that SCN3B and synaptotagmin 11 expression were obviously associated with B cell, macrophage, myeloid dendritic cell, neutrophils, and T cell CD4+ and CD8+ in both colon adenocarcinoma and rectal adenocarcinoma. CHIR-99021, MLN4924, and YK4-279 were identified as the potential drugs for treatment. Finally, upregulated EIOGs genes PPFIA4 and SCN3B were found in colon adenocarcinoma and PPFIA4 and SCN3B were proved to promote cell proliferation and migration in vitro. We demonstrated here that EIOGs promoting a malignancy phenotype was related with poor survival and prognosis in CRC, which might be served as novel therapeutic targets in CRC management.

Development of a novel disulfidptosis-related lncRNA signature for prognostic and immune response prediction in clear cell renal cell carcinoma.

Disulfidptosis, a novel form of regulated cell death, occurs due to the aberrant accumulation of intracellular cystine and other disulfides. Moreover, targeting disulfidptosis could identify promising approaches for cancer treatment. Long non-coding RNAs (lncRNAs) are known to be critically implicated in clear cell renal cell carcinoma (ccRCC) development. Currently, the involvement of disulfidptosis-related lncRNAs in ccRCC is yet to be elucidated. This study primarily dealt with identifying and validating a disulfidptosis-related lncRNAs-based signature for predicting the prognosis and immune landscape of individuals with ccRCC. Clinical and RNA sequencing data of ccRCC samples were accessed from The Cancer Genome Atlas (TCGA) database. Pearson correlation analysis was conducted for the identification of the disulfidptosis-related lncRNAs. Additionally, univariate Cox regression analysis, Least Absolute Shrinkage and Selection Operator Cox regression, and stepwise multivariate Cox analysis were executed to develop a novel risk prognostic model. The prognosis-predictive capacity of the model was then assessed using an integrated method. Variation in biological function was noted using GO, KEGG, and GSEA. Additionally, immune cell infiltration, the tumor mutational burden (TMB), and tumor immune dysfunction and exclusion (TIDE) scores were calculated to investigate differences in the immune landscape. Finally, the expression of hub disulfidptosis-related lncRNAs was validated using qPCR. We established a novel signature comprised of eight lncRNAs that were associated with disulfidptosis (SPINT1-AS1, AL121944.1, AC131009.3, AC104088.3, AL035071.1, LINC00886, AL035587.2, and AC007743.1). Kaplan-Meier and receiver operating characteristic curves demonstrated the acceptable predictive potency of the model. The nomogram and C-index confirmed the strong correlation between the risk signature and clinical decision-making. Furthermore, immune cell infiltration analysis and ssGSEA revealed significantly different immune statuses among risk groups. TMB analysis revealed the link between the high-risk group and high TMB. It is worth noting that the cumulative effect of the patients belonging to the high-risk group and having elevated TMB led to decreased patient survival times. The high-risk group depicted greater TIDE scores in contrast with the low-risk group, indicating greater potential for immune escape. Finally, qPCR validated the hub disulfidptosis-related lncRNAs in cell lines. The established novel signature holds potential regarding the prognosis prediction of individuals with ccRCC as well as predicting their responses to immunotherapy.

Enterotoxigenic Bacteroides fragilis (ETBF) Enhances Colorectal Cancer Cell Proliferation and Metastasis Through HDAC3/miR-139-3p Pathway.

Enterotoxigenic Bacteroides fragilis (ETBF) is believed to promote the malignant process of colorectal cancer (CRC), but the underlying molecular mechanism still needs to be revealed. CRC cells (SW480 and HCT-116) were treated with ETBF strain. Cell proliferation, invasion and, migration were evaluated by cell counting kit 8 assay, EdU assay, colony formation assay, transwell assay, and wound healing assay. Protein expression was analyzed by western blot. MicroRNA (miR)-139-3p and histone deacetylase 3 (HDAC3) expression levels in tissues and cells were determined by qRT-PCR. Xenograft tumor model was conducted to evaluate the effect of miR-139-3p on CRC tumor growth. ETBF treatment could promote CRC cell proliferation, invasion and migration. MiR-139-3p expression was decreased by ETBF, and its overexpression reversed the effect of ETBF on CRC cell progression. HDAC3 negatively regulated miR-139-3p expression, and its overexpression facilitated CRC cell behaviors via reducing miR-139-3p expression. Moreover, HDAC3 expression was increased by ETBF, and its knockdown also abolished ETBF-mediated CRC cell progression. Additionally, miR-139-3p overexpression could reduce CRC tumor growth in vivo. ETBF aggravated CRC proliferation and metastasis via the regulation of HDAC3/miR-139-3p axis. The discovery of ETBF/HDAC3/miR-139-3p axis may provide a new direction for CRC treatment.

Xuebijing improves inflammation and pyroptosis of acute lung injury by up-regulating miR-181d-5p-mediated SPP1 inactivation

Abstract Background Xuebijing (XBJ) is widely applied in the treatment of Acute Lung Injury (ALI). This study focused on the potential mechanism of XBJ in Lipopolysaccharide (LPS)-induced ALI. Methods The rat ALI model was established by injection of LPS (10 mg/kg) and pretreated with XBJ (4 mL/kg) three days before LPS injection. BEAS-2B cell line was stimulated with LPS (1 μg/mL) and ATP (5 mM) to induce pyroptosis, and XBJ (2 g/L) was pretreated 24h before induction. The improvement effects of XBJ on pulmonary edema, morphological changes, and apoptosis in ALI lung tissue were evaluated by lung wet/dry weight ratio, HE-staining, and TUNEL staining. Inflammatory cytokines in lung tissue and cell supernatant were determined by ELISA. pyroptosis was detected by flow cytometry. Meanwhile, the expressions of miR-181d-5p, SPP1, p-p65, NLRP3, ASC, caspase-1, p20, and GSDMD-N in tissues and cells were assessed by RT-qPCR and immunoblotting. The relationship between miR-181d-5p and SPP1 in experimental inflammation was reported by dual luciferase assay. Results XBJ could improve inflammation and pyroptosis of ALI by inhibiting contents of inflammatory cytokines, and levels of inflammation- and pyroptosis-related proteins. Mechanistically, XBJ could up-regulate miR-181d-5p and inhibit SPP1 in ALI. miR-181d-5p can target the regulation of SPP1. Depressing miR-181d-5p compensated for the ameliorative effect of XBJ on ALI, and overexpressing SPP1 suppressed the attenuating effect of XBJ on LPS-induced inflammation and pyroptosis. Conclusion XBJ can regulate the miR-181d-5p/SPP1 axis to improve inflammatory response and pyroptosis in ALI.

LncRNA LIMp27 Regulates the DNA Damage Response through p27 in p53-Defective Cancer Cells.

P53 inactivation occurs in about 50% of human cancers, where p53-driven p21 activity is devoid and p27 becomes essential for the establishment of the G1/S checkpoint upon DNA damage. Here, this work shows that the E2F1-responsive lncRNA LIMp27 selectively represses p27 expression and contributes to proliferation, tumorigenicity, and treatment resistance in p53-defective colon adenocarcinoma (COAD) cells. LIMp27 competes with p27 mRNA for binding to cytoplasmically localized hnRNA0, which otherwise stabilizes p27 mRNA leading to cell cycle arrest at the G0/G1 phase. In response to DNA damage, LIMp27 is upregulated in both wild-type and p53-mutant COAD cells, whereas cytoplasmic hnRNPA0 is only increased in p53-mutant COAD cells due to translocation from the nucleus. Moreover, high LIMp27 expression is associated with poor survival of p53-mutant but not wild-type p53 COAD patients. These results uncover an lncRNA mechanism that promotes p53-defective cancer pathogenesis and suggest that LIMp27 may constitute a target for the treatment of such cancers.

LncRNA MILIP links YBX1 to translational activation of Snai1 and promotes metastasis in clear cell renal cell carcinoma.

BACKGROUND: Distant metastasis is the major cause of clear cell renal cell carcinoma (ccRCC)-associated mortality. However, molecular mechanisms involved in ccRCC metastasis remain to be fully understood. With the increasing appreciation of the role of long non-coding RNAs (lncRNAs) in cancer development, progression, and treatment resistance, the list of aberrantly expressed lncRNAs contributing to ccRCC pathogenesis is expanding rapidly. METHODS: Bioinformatics analysis was carried out to interrogate publicly available ccRCC datasets. In situ hybridization and qRT-PCR assays were used to test lncRNA expression in human ccRCC tissues and cell lines, respectively. Chromatin immunoprecipitation and luciferase reporter assays were used to examine transcriptional regulation of gene expression. Wound healing as well as transwell migration and invasion assays were employed to monitor ccRCC cell migration and invasion in vitro. ccRCC metastasis was also examined using mouse models in vivo. RNA pulldown and RNA immunoprecipitation were performed to test RNA-protein associations, whereas RNA-RNA interactions were tested using domain-specific chromatin isolation by RNA purification. RESULTS: MILIP expression was upregulated in metastatic compared with primary ccRCC tissues. The increased MILIP expression in metastatic ccRCC cells was driven by the transcription factor AP-2 gamma (TFAP2C). Knockdown of MILIP diminished the potential of ccRCC cell migration and invasion in vitro and reduced the formation of ccRCC metastatic lesions in vivo. The effect of MILIP on ccRCC cells was associated with alterations in the expression of epithelial-to-mesenchymal transition (EMT) hallmark genes. Mechanistically, MILIP formed an RNA-RNA duplex with the snail family transcriptional repressor 1 (Snai1) mRNA and bound to Y-box binding protein 1 (YBX1). This promoted the association between the YBX1 protein and the Snai1 mRNA, leading to increased translation of the latter. Snai1 in turn played an important role in MILIP-driven ccRCC metastasis. CONCLUSIONS: The TFAP2C-responsive lncRNA MILIP drives ccRCC metastasis. Targeting MILIP may thus represent a potential avenue for ccRCC treatment.

Successful Production and Ligninolytic Activity of a Bacterial Laccase, Lac51, Made in Nicotiana benthamiana via Transient Expression.

Giant panda could have bamboo as their exclusive diet for about 2 million years because of the contribution of numerous enzymes produced by their gut bacteria, for instance laccases. Laccases are blue multi-copper oxidases that catalyze the oxidation of a broad spectrum of phenolic and aromatic compounds with water as the only byproduct. As a "green enzyme," laccases have potential in industrial applications, for example, when dealing with degradation of recalcitrant biopolymers, such as lignin. In the current study, a bacterial laccase, Lac51, originating from Pseudomonas putida and identified in the gut microbiome of the giant panda's gut was transiently expressed in the non-food plant Nicotiana benthamiana and characterized. Our results show that recombinant Lac51 exhibits bacterial laccase properties, with optimal pH and temperature at 7-8 and 40°C, respectively, when using syringaldazine as substrate. Moreover, we demonstrate the functional capability of the plant expressed Lac51 to oxidize lignin using selected lignin monomers that serve as substrates of Lac51. In summary, our study demonstrates the potential of green and non-food plants as a viable enzyme production platform for bacterial laccases. This result enriches our understanding of plant-made enzymes, as, to our knowledge, Lac51 is the first functional recombinant laccase produced in plants.

De novo Mutation Enables NOTCH3ECD Aggregation and Mitochondrial Dysfunction via Interactions with BAX and BCL-2.

BACKGROUND: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) caused by NOTCH3 mutations is the most common monogenic hereditary pattern of cerebral small vessel disease. The aggregation of the mutant NOTCH3 may play a cytotoxic role in CADASIL. However, the main mechanism of this process remains unclear. OBJECTIVE: We aimed to investigate the possible pathogenesis of the mutant NOTCH3 in CADASIL. METHODS: The clinical information of two pedigrees were collected and analyzed. Furthermore, we constructed cell lines corresponding to this mutation in vitro. The degradation of the extracellular domain of NOTCH3 (NOTCH3ECD) was analyzed by Cycloheximide Pulse-Chase Experiment. Flow cytometry and cell counting kit-8 assay were performed to observe the effects of the NOTCH3 mutation on mitochondrial function and apoptosis. RESULTS: We confirmed a de novo heterozygous missense NOTCH3 mutation (c.1690G > A, p. A564T) in two pedigrees. In vitro, the NOTCH3ECD aggregation of A564T mutant may be related to their more difficult to degrade. The mitochondrial membrane potential was attenuated, and cell viability was significant decreased in NOTCH3ECD A564T group. Interestingly, BAX and cytochrome c were significantly increased, which are closely related to the mitochondrial-mediated pathway to apoptosis. CONCLUSION: In our study, the aggregation of NOTCH3ECD A564T mutation may be associated with more difficult degradation of the mutant, and the aggregation may produce toxic effects to induce apoptosis through the mitochondrial-mediated pathway. Therefore, we speculated that mitochondrial dysfunction may hopefully become a new breakthrough point to explain the pathogenesis of cysteine-sparing NOTCH3 mutations.

The clear cell sarcoma functional genomic landscape.

Clear cell sarcoma (CCS) is a deadly malignancy affecting adolescents and young adults. It is characterized by reciprocal translocations resulting in expression of the chimeric EWSR1-ATF1 or EWSR1-CREB1 fusion proteins, driving sarcomagenesis. Besides these characteristics, CCS has remained genomically uncharacterized. Copy number analysis of human CCSs showed frequent amplifications of the MITF locus and chromosomes 7 and 8. Few alterations were shared with Ewing sarcoma or desmoplastic, small round cell tumors, which are other EWSR1-rearranged tumors. Exome sequencing in mouse tumors generated by expression of EWSR1-ATF1 from the Rosa26 locus demonstrated no other repeated pathogenic variants. Additionally, we generated a new CCS mouse by Cre-loxP-induced chromosomal translocation between Ewsr1 and Atf1, resulting in copy number loss of chromosome 6 and chromosome 15 instability, including amplification of a portion syntenic to human chromosome 8, surrounding Myc. Additional experiments in the Rosa26 conditional model demonstrated that Mitf or Myc can contribute to sarcomagenesis. Copy number observations in human tumors and genetic experiments in mice rendered, for the first time to our knowledge, a functional landscape of the CCS genome. These data advance efforts to understand the biology of CCS using innovative models that will eventually allow us to validate preclinical therapies necessary to achieve longer and better survival for young patients with this disease.

Expression and clinical significance of pyruvate kinase M2 in breast cancer: A protocol for meta-analysis and bioinformatics validation analysis.

BACKGROUND: Breast cancer is a common malignant tumor in women. In recent years, its incidence is increasing year by year, and its morbidity and mortality rank the first place among female malignant tumors. Some key enzymes and intermediates in glycolysis are closely related to tumor development. Pyruvate kinase M2 (PKM2) is an important rate-limiting enzyme in glycolysis pathway. Meanwhile, it is highly expressed in proliferative cells, especially in tumor cells, and plays an important role in the formation of Warburg effect and tumorigenesis. Previous studies have explored the effects of PKM2 expression on the prognosis and clinical significance of breast cancer patients, while the results are contradictory and uncertain. This study uses controversial data for meta-analysis to accurately evaluate the problem. We collected relevant Oncomine and The Cancer Genome Atlas (TCGA) data to further verify the results. Through bioinformatics analysis, the mechanism and related pathways of PKM2 in breast cancer are explored. METHODS: We searched Wanfang, Chinese Biomedical Literature Database, Chinese National Knowledge Infrastructure, the Chongqing VIP Chinese Science and Technology Periodical Database, PubMed, Embase, and Web of Science databases from inception to March 2021. The language restrictions are Chinese and English. The published literatures on PKM2 expression and prognosis or clinicopathological characteristics of breast cancer patients were statistically analyzed. Combined hazard ratios (HRs), odds ratios (ORs), and 95% confidence intervals (95% CIs) were used to evaluate the effects of PKM2 on the prognosis and clinicopathological features of breast cancer. Stata 14.0 software was applied for meta-analysis. Oncomine and TCGA databases were used to meta-analyze the differences of PKM2 mRNA expression between breast cancer and normal breast tissues. The expression of PKM2 protein was verified by Human Protein Atlas (HPA) database. The relationship between the gene and the survival of breast cancer patients was analyzed by Gene Expression Profiling Interactive Analysis (GEPIA). The relationship between PKM2 gene and clinicopathological characteristics was analyzed by using LinkedOmics, and the Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment pathway analysis was performed by using Metascape. Protein-protein interaction (PPI) network was constructed by String website. RESULTS: The results of this meta-analysis will be submitted to a peer-reviewed journal for publication. CONCLUSION: This study provides high-quality medical evidence for the correlation between the expression of PKM2 and the prognosis and clinicopathological features of breast cancer. Through bioinformatics analysis, this study further deepens the understanding of the mechanism and related pathways of PKM2 in breast cancer. ETHICS AND DISSEMINATION: The private information from individuals will not be published. This systematic review also should not damage participants' rights. Ethical approval is not available. The results may be published in a peer-reviewed journal or disseminated in relevant conferences. OSF REGISTRATION NUMBER: DOI 10.17605/OSF.IO/W52HB.

Global Characterization of Immune Infiltration in Clear Cell Renal Cell Carcinoma.

BACKGROUND: Immunotherapy has revolutionized the treatment of clear cell renal cell carcinoma (ccRCC). However, the therapy is constrained by drug resistance. Therefore, further characterization of immune infiltration in ccRCC is needed to improve its efficacy. METHODS: Here, we adopted the CIBERSORT method to analyze the level of 22 immune cells, and analyzed the correlation of immune cells and clinical parameters in ccRCC in The Cancer Genome Atlas. We used consensus clustering to cluster ccRCC and identified differently expressed genes (DEGs) between hot and cold tumors using the "Limma" package, and then performed enrichment analysis of DEGs. Finally, we constructed and validated a Cox regression model using the "survival", "glmnet", and "survivalROC" packages, implemented in R. RESULTS: Regulatory T cells upregulated in tumor tissue increased during tumor progression, and correlated with poor overall survival in ccRCC. Consensus clustering identified four clusters of ccRCC. To elucidate the underlying mechanisms of immune cell infiltration, we subdivided these four clusters into two major types, immune hot and cold, and identified DEGs between them. The results revealed different transcription profiles in the two tumor types, with hot tumors being enriched in immune-related signaling, whereas cold tumors were enriched in extracellular matrix remodeling and the phosphatidylinositol 3-kinase-AKT (PI3K/AKT) pathway. We further identified hub genes and prognostic-related genes from the DEGs, and constructed a Cox regression model for predicting the overall survival of patients with ccRCC. The areas under the receiver operating characteristics curve for the risk model for the training, testing, and external Zhengzhou validation cohorts were 0.834, 0.733, and 0.812, respectively. Notably, gene sets in the prediction model could also predict the overall survival of patients receiving immunotherapy. CONCLUSION: These findings provide a comprehensive characterization of immune infiltration in ccRCC, while the constructed model can be used effectively to predict the overall survival of ccRCC patients.

Dual-binding benzene and rhodamine B conjugate derivatives as fluorescent chemodosimeter for hypochlorite in living cell imaging.

A new probe (SRh) which based on dual-binding benzene and rhodamine B conjugate derivatives for hypochlorite detection was developed. By desulfurization effect, probe SRh displayed"Off-On" switching in its fluorogenic and chromogenic responses to hypochlorite. The detection limit of ClO- was at a low level (up to 2.43 nM). Moreover, probe SRh has been applied in bioimaging with good biocompatibility and low cytotoxicity.

Clinical Applications of DSC-MRI Parameters Assess Angiogenesis and Differentiate Malignant From Benign Soft Tissue Tumors in Limbs.

OBJECTIVE: To investigate the correlation between dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) parameters and angiogenesis and to explore prospectively the feasibility of using DSC-MRI to differentiate malignant from benign soft tissue tumors (STTs) in limbs. METHODS: This prospective study included 33 patients with STTs in limbs who underwent DSC-MRI after bolus Gd-DTPA infusion. All STTs were confirmed by pathological examination after surgery and microvessel density (MVD), vascular endothelial growth factor (VEGF) expression, were evaluated by immune-histochemical analysis. Semiquantitative DSC-MRI parameters, including negative enhancement integral (NEI), maximum slopes of decrease (MSD) and increase (MSI), and mean time to enhancement were calculated by postprocessing in workstation. The correlation was analyzed between DSC-MRI parameters and angiogenesis factors. Then, the DSC-MRI parameters were compared between benign and malignant STTs and evaluated for diagnostic efficiency by receiver operating characteristic. RESULTS: The 33 evaluated tumors were consisted of 13 benign and 20 malignant STTs in limbs. Significant positive correlations were observed between NEI, MSD, MSI and MVD, VEGF (p < 0.05). However, mean time to enhancement had no correlation with MVD and VEGF. The benign and malignant STTs differed significantly in terms of NEI, MSD, and MSI (p < 0.05). The areas under the curve (AUC) of NEI, MSD, and MSI were 0.915, 0.862, and 0.815 for discriminating between benign and malignant STTs, respectively. CONCLUSION: DSC-MRI parameters are positively correlated with MVD and VEGF, which can evaluate angiogenesis indirectly. Furthermore, DSC-MRI can be considered as one of assistant noninvasive MR imaging technique in differentiation between benign and malignant STTs in limbs.

Slc25a36 modulates pluripotency of mouse embryonic stem cells by regulating mitochondrial function and glutathione level.

Mitochondria play a central role in the maintenance of the naive state of embryonic stem cells. Many details of the mechanism remain to be fully elucidated. Solute carrier family 25 member 36 (Slc25a36) might regulate mitochondrial function through transporting pyrimidine nucleotides for mtDNA/RNA synthesis. Its physical role in this process remains unknown; however, Slc25a36 was recently found to be highly expressed in naive mouse embryonic stem cells (mESCs). Here, the function of Slc25a36 was characterized as a maintenance factor of mESCs pluripotency. Slc25a36 deficiency (via knockdown) has been demonstrated to result in mitochondrial dysfunction, which induces the differentiation of mESCs. The expression of key pluripotency markers (Pou5f1, Sox2, Nanog, and Utf1) decreased, while that of key TE genes (Cdx2, Gata3, and Hand1) increased. Cdx2-positive cells emerged in Slc25a36-deficient colonies under trophoblast stem cell culture conditions. As a result of Slc25a36 deficiency, mtDNA of knockdown cells declined, leading to impaired mitochondria with swollen morphology, decreased mitochondrial membrane potential, and low numbers. The key transcription regulators of mitochondrial biogenesis also decreased. These results indicate that mitochondrial dysfunction leads to an inability to support the pluripotency maintenance. Moreover, down-regulated glutathione metabolism and up-regulated focal adhesion reinforced and stabilized the process of differentiation by separately enhancing OCT4 degradation and promoting cell spread. This study improves the understanding of the function of Slc25a36, as well as the relationship of mitochondrial function with naive pluripotency maintenance and stem cell fate decision.

Lipid Supplement in the Cultural Condition Facilitates the Porcine iPSC Derivation through cAMP/PKA/CREB Signal Pathway.

Large numbers of lipids exist in the porcine oocytes and early embryos and have the positive effects on their development, suggesting that the lipids may play an important role in pluripotency establishment and maintenance in pigs. However, the effects of lipids and their metabolites, such as fatty acids on reprogramming and the pluripotency gene expression of porcine-induced pluripotent stem cells (iPSCs), are unclear. Here, we generated the porcine iPSCs that resemble the mouse embryonic stem cells (ESCs) under lipid and fatty-acid-enriched cultural conditions (supplement of AlbuMAX). These porcine iPSCs show positive for the ESCs pluripotency markers and have the differentiation abilities to all three germ layers, and importantly, have the capability of aggregation into the inner cell mass (ICM) of porcine blastocysts. We further confirmed that lipid and fatty acid enriched condition can promote the cell proliferation and improve reprogramming efficiency by elevating cAMP levels. Interestingly, this lipids supplement promotes mesenchymal-epithelial transition (MET) through the cAMP/PKA/CREB signal pathway and upregulates the E-cadherin expression during porcine somatic cell reprogramming. The lipids supplement also makes a contribution to lipid droplets accumulation in the porcine iPSCs that resemble porcine preimplantation embryos. These findings may facilitate understanding of the lipid metabolism in porcine iPSCs and lay the foundation of bona fide porcine embryonic stem cell derivation.

Paracrine osteoprotegerin and ß-catenin stabilization support synovial sarcomagenesis in periosteal cells.

Synovial sarcoma (SS) is an aggressive soft-tissue sarcoma that is often discovered during adolescence and young adulthood. Despite the name, synovial sarcoma does not typically arise from a synoviocyte but instead arises in close proximity to bones. Previous work demonstrated that mice expressing the characteristic SS18-SSX fusion oncogene in myogenic factor 5-expressing (Myf5-expressing) cells develop fully penetrant sarcomagenesis, suggesting skeletal muscle progenitor cell origin. However, Myf5 is not restricted to committed myoblasts in embryos but is also expressed in multipotent mesenchymal progenitors. Here, we demonstrated that human SS and mouse tumors arising from SS18-SSX expression in the embryonic, but not postnatal, Myf5 lineage share an anatomic location that is frequently adjacent to bone. Additionally, we showed that SS can originate from periosteal cells expressing SS18-SSX alone and from preosteoblasts expressing the fusion oncogene accompanied by the added stabilization of ß-catenin, which is a common secondary change in SS. Expression and secretion of the osteoclastogenesis inhibitory factor osteoprotegerin enabled early growth of SS18-SSX2-transformed cells, indicating a paracrine link between the bone and synovial sarcomagenesis. These findings explain the skeletal contact frequently observed in human SS and may provide alternate means of enabling SS18-SSX-driven oncogenesis in cells as differentiated as preosteoblasts.

Lettuce-produced hepatitis C virus E1E2 heterodimer triggers immune responses in mice and antibody production after oral vaccination.

The hepatitis C virus (HCV) is a major etiologic agent for severe liver diseases (e.g. cirrhosis, fibrosis and hepatocellular carcinoma). Approximately 140 million people have chronic HCV infections and about 500 000 die yearly from HCV-related liver pathologies. To date, there is no licensed vaccine available to prevent HCV infection and production of a HCV vaccine remains a major challenge. Here, we report the successful production of the HCV E1E2 heterodimer, an important vaccine candidate, in an edible crop (lettuce, Lactuca sativa) using Agrobacterium-mediated transient expression technology. The wild-type dimer (E1E2) and a variant without an N-glycosylation site in the E2 polypeptide (E1E2∆N6) were expressed, and appropriate N-glycosylation pattern and functionality of the E1E2 dimers were demonstrated. The humoral immune response induced by the HCV proteins was investigated in mice following oral administration of lettuce antigens with or without previous intramuscular prime with the mammalian HEK293T cell-expressed HCV dimer. Immunization by oral feeding only resulted in development of weak serum levels of anti-HCV IgM for both antigens; however, the E1E2∆N6 proteins produced higher amounts of secretory IgA, suggesting improved immunogenic properties of the N-glycosylation mutant. The mice group receiving the intramuscular injection followed by two oral boosts with the lettuce E1E2 dimer developed a systemic but also a mucosal immune response, as demonstrated by the presence of anti-HCV secretory IgA in faeces extracts. In summary, our study demonstrates the feasibility of producing complex viral antigens in lettuce, using plant transient expression technology, with great potential for future low-cost oral vaccine development.

LRP5 Signaling in Osteosarcomagenesis: a Cautionary Tale of Translation from Cell Lines to Tumors.

Previous reports document expression of low-density lipoprotein receptor-related protein 5 (LRP5) in osteosarcoma (OS) tissue. Expression of this Wnt receptor correlated with metastatic disease and poor disease-free survival. Forced expression of dominant-negative LRP5 (dnLRP5), which lacks the membrane binding domain of the native protein and therefore functions as a soluble receptor-sponge for Wnt ligands, reduced in vitro cellular invasion and in vivo xenograft tumor growth for osteosarcoma cell lines. Here, we use a genetically engineered mouse model of osteosarcomagenesis with and without expression of dnLRP5 to assess to what degree tumorigenesis is affected and whether Wnt/ß-catenin signaling is circumvented or maintained. Each cohort of mice developed osteosarcoma at a similar ultimate prevalence, but after a slightly increased latency in those also expressing dnLRP5. On histology, there was no difference between groups, despite previous reports that the dnLRP5 osteosarcoma cells specifically undergo a mesenchymal-to-epithelial transition in vitro. Finally, immunohistochemistry showed the presence of cytosolic and nuclear ß-catenin and nuclear Cyclin D1, markers consistent with preserved Wnt/ß-catenin signaling despite constitutive blockade of the cell surface receipt of Wnt signaling ligand. These data suggest that canonical Wnt signaling plays a role in OS progression and that while blockade of singular nodes in signaling pathways can have dramatic effects on individual cell lines, real tumors readily evade such focused attacks.

Production of dengue virus envelope protein domain III-based antigens in tobacco chloroplasts using inducible and constitutive expression systems.

Dengue fever is a disease in many parts of the tropics and subtropics and about half the world's population is at risk of infection according to the World Health Organization. Dengue is caused by any of the four related dengue virus serotypes DEN-1, -2, -3 and -4, which are transmitted to people by Aedes aegypti mosquitoes. Currently there is only one vaccine (Dengvaxia(®)) available (limited to a few countries) on the market since 2015 after half a century's intensive efforts. Affordable and accessible vaccines against dengue are hence still urgently needed. The dengue envelop protein domain III (EDIII), which is capable of eliciting serotype-specific neutralizing antibodies, has become the focus for subunit vaccine development. To contribute to the development of an accessible and affordable dengue vaccine, in the current study we have used plant-based vaccine production systems to generate a dengue subunit vaccine candidate in tobacco. Chloroplast genome engineering was applied to express serotype-specific recombinant EDIII proteins in tobacco chloroplasts using both constitutive and ethanol-inducible expression systems. Expression of a tetravalent antigen fusion construct combining EDIII polypeptides from all four serotypes was also attempted. Transplastomic EDIII-expressing tobacco lines were obtained and homoplasmy was verified by Southern blot analysis. Northern blot analyses showed expression of EDIII antigen-encoding genes. EDIII protein accumulation levels varied for the different recombinant EDIII proteins and the different expression systems, and reached between 0.8 and 1.6 % of total cellular protein. Our study demonstrates the suitability of the chloroplast compartment as a production site for an EDIII-based vaccine candidate against dengue fever and presents a Gateway(®) plastid transformation vector for inducible transgene expression.