Promoting differentiation and lipid metabolism are the primary effects for DINP exposure on 3T3-L1 preadipocytes.

Diisononyl phthalate (DINP) is a high-molecular-weight phthalate, and has been recently introduced as di-(2-ethyl hexyl) phthalate (DEHP) substitute and commonly used in a large variety of plastic items. The fat tissue is an important target for DINP exposure, however, very little is understood about its toxicity and mechanism(s) in adipocyte cells. Therefore, the present work aimed to investigate the role of DINP in adipogenesis using 3T3-L1 preadipocytes. DINP exposure for 10 days extensively induced adipogenesis in 3T3-L1 preadipocytes to adipocytes as assessed by lipid accumulation and gene expression of adipogenic markers. The RT-qPCR results showed that DINP could upregulate the expression of peroxisome proliferator-activated receptor-gamma (PPARγ), CCAAT/enhancer-binding protein alpha (C/EBPα) and C/EBPß, while the expression of sterol regulatory element binding transcription factor 1 (SREBF1) and C/EBPδ was not affected. The DINP-induced adipogenesis could be inhibited by using the selective PPARγ antagonist GW9662. The RNA-seq analysis was used to study the systemic toxicities of DINP on preadipocytes. A total of 1181 differently expressed genes (DEGs) (640 genes were up-regulated, 541 genes were down-regulated) were detected in 3T3-L1 preadipocytes under 50 µM DINP. The GO enrichment showed the GO term of "fat cell differentiation" was the most significantly affected metabolic functions, and the KEGG pathway enrichment showed the PPAR pathway was the top affected pathway. The interactive pathway (iPath) analysis showed that the changed metabolic pathways were focus on the lipid metabolism.

MicroRNA-27 inhibits adipogenic differentiation in orbital fibroblasts from patients with Graves' orbitopathy.

BACKGROUND: To investigate the role of microRNA (miR)-27a and miR-27b in adipogenesis in an in vitro model of Graves' orbitopathy (GO). METHODS: Orbital fat tissues were harvested from GO and non-GO participants for primary orbital fibroblast cultures. The expression levels of miR-27a and miR-27b between GO and non-GO orbital fat tissues were compared. During adipogenesis of GO orbital fibroblasts, the expression levels of miR-27a and miR-27b were determined, and the effects of mimics of miR-27a and miR-27b transfection on adipogenesis of GO orbital fibroblast were investigated. RESULTS: Real time-polymerase chain reaction showed significantly more decreases in miR-27a and miR-27b levels in orbital fat tissues in GO participants than in non-GO participants (p < 0.05). The expression of both miR-27a and miR-27b was highest in orbital fibroblasts at day 0 and declined gradually after the induction of adipogenic differentiation. The expression levels of PPARγ, CCAAT/enhancer binding protein (C/EBP)α and C/EBPß were decreased and Oil Red O-stained lipid droplets were lower in GO orbital fibroblasts transfected with miR-27a and miR-27b mimics than in negative controls. CONCLUSIONS: Our results indicated that miR-27a and miR-27b inhibited adipogenesis in orbital fibroblasts from GO patients. Further studies are required to examine the potential of miR-27a and miR-27b as targets for therapeutic strategies.

Identification of a novel enhancer of CEBPE essential for granulocytic differentiation.

CCAAT/enhancer binding protein ε (CEBPE) is an essential transcription factor for granulocytic differentiation. Mutations of CEBPE occur in individuals with neutrophil-specific granule deficiency (SGD), which is characterized by defects in neutrophil maturation. Cebpe-knockout mice also exhibit defects in terminal differentiation of granulocytes, a phenotype reminiscent of SGD. Analysis of DNase I hypersensitive sites sequencing data revealed an open chromatin region 6 kb downstream of the transcriptional start site of Cebpe in murine myeloid cells. We identified an interaction between this +6-kb region and the core promoter of Cebpe using circular chromosome conformation capture sequencing (4C-seq). To understand the role of this putative enhancer in transcriptional regulation of Cebpe, we targeted it using catalytically inactive Cas9 fused to Krüppel-associated box (KRAB) domain and observed a significant downregulation of transcript and protein levels of CEBPE in cells expressing guide RNA targeting the +6-kb region. To further investigate the role of this novel enhancer further in myelopoiesis, we generated mice with deletion of this region using CRISPR/Cas9 technology. Germline deletion of the +6-kb enhancer resulted in reduced levels of CEBPE and its target genes and caused a severe block in granulocytic differentiation. We also identified binding of CEBPA and CEBPE to the +6-kb enhancer, which suggests their role in regulating the expression of Cebpe In summary, we have identified a novel enhancer crucial for regulating expression of Cebpe and required for normal granulocytic differentiation.

RUNX1 mutations enhance self-renewal and block granulocytic differentiation in human in vitro models and primary AMLs.

To unravel molecular mechanisms by which Runt-related transcription factor 1 (RUNX1) mutations contribute to leukemic transformation, we introduced the RUNX1-S291fs300X mutation in human CD34+ stem/progenitor cells and in human induced pluripotent stem cells (iPSCs). In both models, RUNX1mut overexpression strongly impaired myeloid commitment. Instead, self-renewal was enhanced, as shown, by increased long-term culture-initiating cell frequencies and enhanced colony-forming cell replating capacity. Long-term suspension cultures with RUNX1mut-transduced cord blood (CB) CD34+ cells continued for more than 100 days, during which the cells displayed an immature granulocyte-macrophage progenitor-like CD34+/CD123+/CD45RA+ phenotype. The CD34+/CD38- hematopoietic stem cell (HSC) population most likely acted as cell of origin, as HSCs provided the best long-term proliferative potential on overexpression of RUNX1mut. CEBPA expression was reduced in RUNX1mut cells, and reexpression of CEBPA partly restored differentiation. RNA-seq analysis on CB/iPSC systems and on primary patient samples confirmed that RUNX1 mutations induce a myeloid differentiation block, and that a common set of RUNX1mut-upregulated target genes was strongly enriched for gene ontology terms associated with nucleosome assembly and chromatin structure. Interestingly, in comparison with AML1-ETO binding in acute myeloid leukemias (AMLs), we found significantly distinct genomic distribution and differential expression for RUNX1mut of genes such as TCF4, MEIS1, and HMGA2 that may potentially contribute to the underlying difference in clinical outcomes between RUNX1mut and AML1-ETO patients. In conclusion, RUNX1mut appears to induce a specific transcriptional program that contributes to leukemic transformation.

Loss of CCAAT-enhancer-binding protein alpha (CEBPA) is linked to poor prognosis in PTEN deleted and TMPRSS2:ERG fusion type prostate cancers.

BACKGROUND: The transcription factor CCAAT-enhancer-binding protein alpha (CEBPA) is a crucial regulator of cell proliferation and differentiation. Expression levels of CEBPA have been suggested to be prognostic in various tumor types. METHODS: Here, we analyzed the immunohistochemical expression of CEBPA in a tissue microarray containing more than 17 000 prostate cancer specimens with annotated clinical and molecular data including for example TMPRSS2:ERG fusion and PTEN deletion status. RESULTS: Normal prostate glands showed moderate to strong CEBPA staining, while CEBPA expression was frequently reduced (40%) or lost (30%) in prostate cancers. Absence of detectable CEBPA expression was markedly more frequent in ERG negative (45%) as compared to ERG positive cancers (20%, P < 0.0001). Reduced CEBPA expression was linked to unfavorable phenotype (P < 0.0001) and poor prognosis (P = 0.0008). Subgroup analyses revealed, that the prognostic value of CEBPA loss was entirely driven by tumors carrying both TMPRSS2:ERG fusions and PTEN deletions. In this subgroup, CEBPA loss was tightly linked to advanced tumor stage (P < 0.0001), high Gleason grade (P < 0.0001), positive nodal stage (0.0003), and early biochemical recurrence (P = 0.0007), while these associations were absent or markedly diminished in tumors with normal PTEN copy numbers and/or absence of ERG fusion. CONCLUSIONS: CEBPA is down regulated in about one third of prostate cancers, but the clinical impact of CEBPA loss is strictly limited to the subset of about 10% prostate cancers carrying both ERG fusion and deletions of the PTEN tumor suppressor. Our findings challenge the concept that prognostic molecular markers may be generally applicable to all prostate cancers.

An integrative model for alternative polyadenylation, IntMAP, delineates mTOR-modulated endoplasmic reticulum stress response.

3'-untranslated regions (UTRs) can vary through the use of alternative polyadenylation sites during pre-mRNA processing. Multiple publically available pipelines combining high profiling technologies and bioinformatics tools have been developed to catalog changes in 3'-UTR lengths. In our recent RNA-seq experiments using cells with hyper-activated mammalian target of rapamycin (mTOR), we found that cellular mTOR activation leads to transcriptome-wide alternative polyadenylation (APA), resulting in the activation of multiple cellular pathways. Here, we developed a novel bioinformatics algorithm, IntMAP, which integrates RNA-Seq and PolyA Site (PAS)-Seq data for a comprehensive characterization of APA events. By applying IntMAP to the datasets from cells with hyper-activated mTOR, we identified novel APA events that could otherwise not be identified by either profiling method alone. Several transcription factors including Cebpg (CCAAT/enhancer binding protein gamma) were among the newly discovered APA transcripts, indicating that diverse transcriptional networks may be regulated by mTOR-coordinated APA. The prevention of APA in Cebpg using the CRISPR/cas9-mediated genome editing tool showed that mTOR-driven 3'-UTR shortening in Cebpg is critical in protecting cells from endoplasmic reticulum (ER) stress. Taken together, we present IntMAP as a new bioinformatics algorithm for APA analysis by which we expand our understanding of the physiological role of mTOR-coordinated APA events to ER stress response. IntMAP toolbox is available at http://compbio.cs.umn.edu/IntMAP/.

Molecular cloning, characterization and expression analysis of C/EBP α, ß and δ in adipose-related tissues and adipocyte of duck (Anas platyrhynchos).

CCAAT/enhancer binding protein α, ß, δ (C/EBP α, ß, δ) are essential transcriptional factors in regulating adipose development. However, information about their sequence characteristics and functions during adipocyte development still remains scarce in birds. In present study, we found that duck C/EBP α, ß, δ differed in their phosphorylation sites and low complexity regions (LCRs) among their orthologs and paralogs. Phylogenetic analysis showed that C/EBP α, ß, δ had different evolutionary patterns, and each of duck C/EBP α, ß, δ was strikingly diverged from orthologs of other Aves. Results of quantitative real-time PCR exhibited that C/EBP α, ß, δ were all highly expressed in duck adipose tissues. Indeed, investigations of changes in both their mRNA levels and lipid droplet content during duck adipocytes differentiation showed that their expression profiles were closely related to cellular lipid accumulation. Furthermore, hierarchical clustering analysis of the C/EBPs and lipid metabolism-related genes expression profiles showed that C/EBP α was clustered with genes related to lipolysis, lipogenesis and fatty acid desaturation, whereas C/EBP ß, δ were clustered with genes related to de novo lipogenesis and fatty acid elongation, which were different from mammals. In summary, C/EBP α, ß, δ of duck differ from other species in their structures and have different effects on lipid metabolism during adipocytes differentiation. This research serve as a foundation for further investigations about avian C/EBP α, ß, δ in adipocytes differentiation and adipose development.

Modulation of Adipocyte Differentiation and Proadipogenic Gene Expression by Sulforaphane, Genistein, and Docosahexaenoic Acid as a First Step to Counteract Obesity.

Obesity is characterized by excess body fat accumulation due to an increase in the size and number of differentiated mature adipocytes. Adipocyte differentiation is regulated by genetic and environmental factors, and its inhibition could represent a strategy for obesity prevention and treatment. The current study was designed with two aims: (i) to evaluate the changes in the expression of adipogenic markers (C/EBPα, PPARγ variant 1 and variant 2, and GLUT4) in 3T3-L1 murine preadipocytes at four stages of the differentiation process and (ii) to compare the effectiveness of sulforaphane, genistein, and docosahexaenoic acid in reducing lipid accumulation and modulating C/EBPα, PPARγ1, PPARγ2, and GLUT4 mRNA expression in mature adipocytes. All bioactive compounds were shown to suppress adipocyte differentiation, although with different effectiveness. These results set the stage for further studies considering natural food constituents as important agents in preventing or treating obesity.

Subclinical cutaneous inflammation remained after permeability barrier disruption enhances UV sensitivity by altering ER stress responses and topical pseudoceramide prevents them.

Stratum corneum forms the UV barrier. The effect of ultraviolet B (UVB) on normal skin was extensively studied; however, its effect on barrier perturbed skin remains undefined. Both barrier perturbation and UVB irradiation induce endoplasmic reticulum (ER) stress and unfolded protein response (UPR) in keratinocytes. Mild ER stress activates homeostatic UPR, while severe ER stress leads to abnormal UPR, promoting apoptosis and inflammation. Here, we investigated UV sensitivity and UVB-induced UPR in barrier-disrupted human skin and the effects of pseudoceramide-dominant emollient on UVB-induced skin responses. Tape-stripped skin of healthy volunteers showed enhanced susceptibility to erythema and augmented proinflammatory cytokines induction following suberythemal UVB irradiation. Suberythemal UVB activated XBP1 in normal skin, while increased CHOP transcription in barrier perturbed skin. After tape stripping, pseudoceramide-dominant emollient was applied for 3 days, and then, the areas were irradiated with suberythemal UVB. Pretreatment with topical pseudoceramide protected against UVB-induced upregulation of IL-1ß, IL-6, and TNF-α transcription and reduced susceptibility to erythema following UVB. Topical pseudoceramide also suppressed suberythemal UVB-induced CHOP transcription in barrier-disrupted skin. Taken together, these data indicate that permeability barrier disruption increases UV sensitivity in human skin, partly via switch the UVB-induced UPR, from homeostatic signals to pro-apoptotic and proinflammatory signals. In addition, we conclude that pseudoceramide-dominant emollient suppresses excessive ER stress induction and CHOP activation following UVB in barrier damaged skin, providing evidence that pseudoceramide-dominant emollients can be promising strategies for photoprotection of the barrier damaged skin.

DNMT1 mutations found in HSANIE patients affect interaction with UHRF1 and neuronal differentiation.

DNMT1 is recruited to substrate sites by PCNA and UHRF1 to maintain DNA methylation after replication. The cell cycle dependent recruitment of DNMT1 is mediated by the PCNA-binding domain (PBD) and the targeting sequence (TS) within the N-terminal regulatory domain. The TS domain was found to be mutated in patients suffering from hereditary sensory and autonomic neuropathies with dementia and hearing loss (HSANIE) and autosomal dominant cerebellar ataxia deafness and narcolepsy (ADCA-DN) and is associated with global hypomethylation and site specific hypermethylation. With functional complementation assays in mouse embryonic stem cells, we showed that DNMT1 mutations P496Y and Y500C identified in HSANIE patients not only impair DNMT1 heterochromatin association, but also UHRF1 interaction resulting in hypomethylation. Similar DNA methylation defects were observed when DNMT1 interacting domains in UHRF1, the UBL and the SRA domain, were deleted. With cell-based assays, we could show that HSANIE associated mutations perturb DNMT1 heterochromatin association and catalytic complex formation at methylation sites and decrease protein stability in late S and G2 phase. To investigate the neuronal phenotype of HSANIE mutations, we performed DNMT1 rescue assays and could show that cells expressing mutated DNMT1 were prone to apoptosis and failed to differentiate into neuronal lineage. Our results provide insights into the molecular basis of DNMT1 dysfunction in HSANIE patients and emphasize the importance of the TS domain in the regulation of DNA methylation in pluripotent and differentiating cells.

Globular adiponectin inhibits leptin-stimulated esophageal adenocarcinoma cell proliferation via adiponectin receptor 2-mediated suppression of UHRF1.

Esophageal adenocarcinoma (EAC) is one of the most common malignancies in the world which is associated the increased prevalence of obesity. In the context of obesity, leptin can directly contribute to progression of EAC. Adiponectin inhibits leptin-induced oncogenic signaling in EAC cells. However, the exact molecular mechanisms linking obesity, adipokines, and EAC remain far from completely understood. In the present study, we tested the role of ubiquitin-like with PHD and ring finger domains 1 (UHRF1) in adiponectin-induced protective effects against leptin-induced EAC cell proliferation. We found that globular adiponectin (gAD) significantly inhibited leptin-induced increase of cell proliferation and decrease of apoptosis in OE 19 cells. Moreover, leptin-induced increase of UHRF1 expression was suppressed by gAD. Compared with normal controls, UHRF1 expression was markedly increased in EAC tissues and cell lines. Silence of UHRF1 increased the expression of cleaved caspase 3 and 9 and Bax, reduced the expression of Bcl-2, promoted apoptosis, and inhibited cell proliferation in OE 19 cells. Overexpression of UHRF1 significantly blocked gAD-induced decrease of cell proliferation and increase of apoptosis in leptin-treated cells. Silence of adiponectin receptor 1/2 (AdipoR1/2) could inhibit gAD-induced decrease of cell proliferation and increase of apoptosis in leptin-treated cells. Silence of AdipoR2, but not AdipoR1, suppressed gAD-induced decrease of UHRF1 expression in leptin-treated cells. The results indicated that gAD inhibited the prooncogenic effects of leptin via AdipoR2-mediated suppression of UHRF1. Our study provides novel insights into the role of UHRF1 in the development of EAC and the mechanism of antitumor effect of gAD.

Effect of dihydroartemisinin on UHRF1 gene expression in human prostate cancer PC-3 cells.

As the second most common cancer in men around the world, prostate cancer is increasingly gaining more attention. Dihydroartemisinin (DHA) has been proven to be a promising anticancer agent in vitro as well as in vivo in accumulating data. However, the detailed mechanisms of how DHA action in human prostate cancer PC-3 cells remain elusive. This study aimed to investigate the effects of DHA, a novel anticancer agent, by inhibiting the expression of ubiquitin like containing PHD and ring finger 1 (UHRF1) in PC-3 cells. The apoptosis and cell-cycle distribution were detected by flow cytometry. Quantitative real-time PCR was performed to examine both UHRF1 and DNA methyltransferase 1 (DNMT1) expressions at mRNA levels, whereas the expressions of UHRF1, DNMT1, and p16 proteins at protein levels were detected by Western blotting. Methylation levels of p16 CpG islands were determined by bisulfite genomic sequencing. We showed that DHA induced the downregulation of UHRF1 and DNMT1, accompanied by an upregulation of p16 in PC-3 cells. Decreased p16 promoter methylation levels in DHA-treated groups were also observed in PC-3 cells. Furthermore, DHA significantly induced apoptosis and G1/S cell-cycle arrest in PC-3 cells. Our results suggested that downregulation of UHRF1/DNMT1 is upstream to many cellular events, including G1 cell arrest, demethylation of p16, and apoptosis. Together, our study provides new evidence that DHA may serve as a potential therapeutic agent in the treatment of prostate cancer.

Comparative Transcriptomic and Epigenomic Analyses Reveal New Regulators of Murine Brown Adipogenesis.

Increasing energy expenditure through brown adipocyte recruitment is a promising approach to combat obesity. We report here the comprehensive profiling of the epigenome and transcriptome throughout the lineage commitment and differentiation of C3H10T1/2 mesenchymal stem cell line into brown adipocytes. Through direct comparison to datasets from differentiating white adipocytes, we systematically identify stage- and lineage-specific coding genes, lncRNAs and microRNAs. Utilizing chromatin state maps, we also define stage- and lineage-specific enhancers, including super-enhancers, and their associated transcription factor binding motifs and genes. Through these analyses, we found that in brown adipocytes, brown lineage-specific genes are pre-marked by both H3K4me1 and H3K27me3, and the removal of H3K27me3 at the late stage is necessary but not sufficient to promote brown gene expression, while the pre-deposition of H3K4me1 plays an essential role in poising the brown genes for expression in mature brown cells. Moreover, we identify SOX13 as part of a p38 MAPK dependent transcriptional response mediating early brown cell lineage commitment. We also identify and subsequently validate PIM1, SIX1 and RREB1 as novel regulators promoting brown adipogenesis. Finally, we show that SIX1 binds to adipogenic and brown marker genes and interacts with C/EBPα, C/EBPß and EBF2, suggesting their functional cooperation during adipogenesis.

Clinicopathological analysis of UHRF1 expression in medulloblastoma tissues and its regulation on tumor cell proliferation.

Studies have showed the involvement of ubiquitin-like with PHD and RING finger domains 1 (UHRF1) in tumorigenesis and progression. This study focused on the relationships between UHRF1 and medulloblastoma (MB). Immunostaining and western blotting demonstrated differential expression of UHRF1 in MB tissues and no UHRF1 expression in normal cerebellum tissues. Univariate survival analysis revealed MB patients with high UHRF1 expression had significantly shorter OS and PFS than patients with low UHRF1 (OS p = 0.009, PFS p = 0.003). Multivariate analysis illustrated that UHRF1 expression level is an independent prognostic factor influencing the OS and PFS (OS p = 0.038, PFS p = 0.014). UHRF1 expression levels were significantly different among molecular subgroups of MB (p = 0.003). Down-regulation of UHRF1 by RNAi inhibited proliferation and clonogenic ability of MB cell lines with cell cycle arrest in G1/G2-phase. Meanwhile, cells transfected with lenti-shUHRF1 showed increased p16 expression and location shift of CDK4 in MB cells. These findings indicate UHRF1 may promote cell proliferation and be a potential biomarker that can be used as a prognostic parameter and a therapeutic target for MB.

RAF-1/MEK/ERK pathway regulates ATRA-induced differentiation in acute promyelocytic leukemia cells through C/EBPß, C/EBPε and PU.1.

MEK/ERK signal pathway was required for the differentiation of granulocytes, megakaryocytes and erythrocytes. Recently, MEK/ERK cascade was reported to be involved in all-trans retinoic acid (ATRA) induced differentiation in acute promyelocytic leukemia (APL) cells. However, the upstream and downstream molecules of MEK/ERK signal pathway in this cell model remains to be elucidated. In this work, we showed that RAF-1 was activated and the blockade of RAF-1 activation attenuated MEK/ERK activation as well as ATRA-induced differentiation. ATRA-enhanced protein levels of C/EBPß, C/EBPε and PU.1, which were required for differentiation in APL cells, were suppressed by the specific inhibitor of MEK. However, MEK inhibition had no effect on the degradation of PML-RARα fusion protein or the restoration of PML nuclear bodies by ATRA treatment. Taken together, our study suggested that RAF-1/MEK/ERK cascade was involved in ATRA-induced differentiation in APL cells through enhancing the protein level of C/EBPß, C/EBPε and PU.1.

The prognostic value of UHRF-1 and p53 in gastric cancer.

BACKGROUND/AIMS: This study aimed to examine whether UHRF-1 and p53 overexpression is a prognostic marker for gastric cancer. PATIENTS AND METHODS: Sixty-four patients with gastric cancer (study group) and 23 patients with gastritis (control group) were evaluated. Immunohistochemistry was used to examine expression of UHRF-1 and p53 in gastric cancers and a control group diagnosed with gastritis. RESULTS: The median age was 63 years (18-83 years) in the study group. UHRF-1 was positive in 15 (23%) patients with gastric cancer and fi ve (21.7%) patients with gastritis (P = 0.559). UHRF1 expression level in gastric cancer is more powerful than in gastritis (P = 0.046). Thirty-seven (61%) patients with gastric cancer and only one patient with gastritis were p53 positive (P < 0.001). After a median follow-up of 12 months (1-110), the 2-year overall survival rates were 55% and 30% in negative and positive p53, respectively (P = 0.084). Also, the 2-year overall survival rates were 45% and 53% in negative and positive UHRF-1, respectively (P = 0.132). CONCLUSION: According to this study, UHRF-1 and p53 were not prognostic factors for gastric cancer, whereas they may have a diagnostic value for differentiating between gastric cancer and gastritis.

The correlation between miR-146a C/G polymorphism and UHRF1 gene expression level in gastric tumor.

OBJECTIVE: To investigate the association between the polymorphism of miR-146a and The ubiquitin-like with PHD and ring-finger domains 1 (UHRF1) expression in patients with gastric cancer. METHODS: MiR-146a rs2910164 was genotyped in 130 patients with gastric cancer and 130 cancer-free individuals using polymerase chain reaction (PCR)-restriction fragment length polymorphism. UHRF1 expression was analyzed in 22 gastric cancer tissues and their adjacent normal tissues using quantitative real-time PCR. RESULTS: No significant differences in genotype distributions of miR-146a rs2910164 were found between cases and controls, but we observed that grade II tumors were more frequently detected in patients with CG/CC genotype compared to those with CC genotype. UHRF1 expressions in cancerous tissues were significantly higher than in noncancerous tissues (1.89-fold). Patients with CC genotype showed a significant increase in UHRF1 expression in comparison to the carriers of GG/CG genotype. A higher UHRF1 expression was associated with cancer stage IV and grade III (P<0.05). CONCLUSION: The overexpression of UHRF1 was correlated with the stage and grade of gastric cancer and is associated with the genotype distribution of rs2910164.

Hispolon from Phellinus linteus induces apoptosis and sensitizes human cancer cells to the tumor necrosis factor-related apoptosis-inducing ligand through upregulation of death receptors.

The tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a potent anticancer agent possessing the ability to induce apoptosis in various cancer cells but not in non­malignant cells. However, certain type of cancer cells are resistant to TRAIL­induced apoptosis and some acquire resistance after the first treatment. So development of an agent that can reduce or avoid resistance in TRAIL­induced apoptosis has garnered significant attention. The present study evaluated the anticancer potential of hispolon in TRAIL­induced apoptosis and indicated hispolon can sensitize cancer cells to TRAIL. As the mechanism of action was examined, hispolon was found to activate caspase­3, caspase­8 and caspase­9, while downregulating the expression of cell survival proteins such as cFLIP, Bcl­2 and Bcl­xL and upregulating the expression of Bax and truncated Bid. We also found hispolon induced death receptors in a non­cell type­specific manner. Upregulation of death receptors by hispolon was found to be p53-independent but linked to the induction of CAAT enhancer binding protein homologous protein (CHOP). Overall, hispolon was demonstrated to potentiate the apoptotic effects of TRAIL through downregulation of anti­apoptotic proteins and upregulation of death receptors linked with CHOP and pERK elevation.

Modification of oil and glucosinolate content in canola seeds with altered expression of Brassica napus LEAFY COTYLEDON1.

Over the last few decades, research focusing on canola (Brassica napus L.) seed oil content and composition has expanded. Oil production and accumulation are influenced by genes participating in embryo and seed development. The Arabidopsis LEAFY COTYLEDON1 (LEC1) is a well characterized regulator of embryo development that also enhances the expression of genes involved in fatty acid (FA) synthesis. B. napus lines over-expressing or down-regulating BnLEC1 were successfully generated by Agrobacterium-mediated transformation. The constitutive expression of BnLEC1 in B. napus var. Polo, increased seed oil content by 7-16%, while the down-regulation of BnLEC1 in B. napus var. Topas reduced oil content by 9-12%. Experimental manipulation of BnLEC1 caused transcriptional changes in enzymes participating in sucrose metabolism, glycolysis, and FA biosynthesis, suggesting an enhanced carbon flux towards FA biosynthesis in tissues over-expressing BnLEC1. The increase in oil content induced by BnLEC1 was not accompanied by alterations in FA composition, oil nutritional value or glucosinolate (GLS) levels. Suppression of BnLEC1 reduced seed oil accumulation and elevated the level of GLS possibly through the transcriptional regulation of BnST5a (Sulphotransferase5a), the last GLS biosynthetic enzyme. Collectively, these findings demonstrate that experimental alterations of BnLEC1 expression can be used to influence oil production and quality in B. napus.

C/EBPα negatively regulates SIRT7 expression via recruiting HDAC3 to the upstream-promoter of hepatocellular carcinoma cells.

Mammalian Sirtuin proteins (SIRTs) are homologs of yeast Sir2, and characterized as class III histone deacetylases of NAD(+) dependence. Unlike their lower counterparts that are directly involved in the extending of lifespan, mammalian SIRTs mainly function in metabolism and cellular homeostasis, among them, SIRT7 is the least understood. SIRT7 is localized in the nucleus and rich in nucleoli associated with RNA polymerase I, and correlated with cell proliferation. In contrast, SIRT7 has recently been demonstrated to specifically deacetylate H3K18ac in the chromatin, and in most cases represses proliferation. Although MicroRNA as miR-125b has been reported to down-regulate SIRT7 by binding to its 3'UTR, however, how SIRT7 gene is regulated remains unclear. Here, we identified the transcription initiation site of human SIRT7 gene at the upstream 23rd A nucleotide respective to the translational codon, and the SIRT7 is a TATA-less and initiator-less gene. The sequences in the upstream region between -256 and -129 bp are identical with important functions in the three species detected. A C/EBPα responding element is found that binds both C/EBPα and C/EBPß in vitro. We showed TSA induced SIRT7 gene transcription and only the HDAC3, but not its catalytic domain depleted mutant, interacted with C/EBPα to occupy the C/EBPα element and repressed SIRT7 gene in the hepatocellular carcinoma cells. To our knowledge, this is the first report on the regulation mechanism of SIRT7 gene, in which, HDAC3 collaborated with C/EBPα to occupy its responding element in the upstream region of SIRT7 gene and repressed its expression in human cells.