Synthesis of α-arylthioacetones using TEMPO as the C3 synthon via a reaction cascade of sequential oxidation, skeletal rearrangement and C-S bond formation.

Here, we present an unprecedented pathway to α-sulfenylated carbonyl compounds from commercially available thiols and universally employed TEMPO and its analogues, which act as C3 synthons through skeletal rearrangement under simple and metal-free conditions. Mechanism studies suggest that this reaction involves a consecutive radical oxidation and cation coupling process. TEMPO analogues and thiols serve as oxidants and reductive reagents, respectively, along the radical process, while in the coupling process, the former ones afford C3 synthons to couple with related sulfur sources.

Histone demethylase KDM3A is required for enhancer activation of hippo target genes in colorectal cancer.

Hippo pathway is involved in tumorigenesis, and its regulation in cytosol has been extensively studied, but its regulatory mechanisms in the nuclear are not clear. In the current study, using a FBS-inducing model following serum starvation, we identified KDM3A, a demethylase of histone H3K9me1/2, as a positive regulator for hippo target genes. KDM3A promotes gene expression through two mechanisms, one is to upregulate YAP1 expression, and the other is to facilitate H3K27ac on the enhancers of hippo target genes. H3K27ac upregulation is more relevant with gene activation, but not H3K4me3; and KDM3A depletion caused H3K9me2 upregulation mainly on TEAD1-binding enhancers rather than gene bodies, further resulting in H3K27ac decrease, less TEAD1 binding on enhancers and impaired transcription. Moreover, KDM3A is associated with p300 and required for p300 recruitment to enhancers. KDM3A deficiency delayed cancer cell growth and migration, which was rescued by YAP1 expression. KDM3A expression is correlated with YAP1 and hippo target genes in colorectal cancer patient tissues, and may serve as a potential prognosis mark. Taken together, our study reveals novel mechanisms for hippo signaling and enhancer activation, which is critical for tumorigenesis of colorectal cancer.

NaI-mediated divergent synthesis of isatins and isoindigoes: a new protocol enabled by an oxidation relay strategy.

A new approach for the synthesis of isatins and isoindigoes by an inexpensive and environmentally friendly NaI-mediated transformation is disclosed. The selectivity could be switched by simply varying the solvent, and isatins (using THF) and isoindigoes (using DMSO) could be obtained in moderate to excellent yields.

Epigenomic analysis in a cell-based model reveals the roles of H3K9me3 in breast cancer transformation.

AIM: Epigenetic marks are critical regulators of chromatin and gene activity. Their roles in normal physiology and disease states, including cancer development, still remain elusive. Herein, the epigenomic change of H3K9me3, as well as its potential impacts on gene activity and genome stability, was investigated in an in vitro breast cancer transformation model. METHODS: The global H3K9me3 level was studied with western blotting. The distribution of H3K9me3 on chromatin and gene expression was studied with ChIP-Seq and RNA-Seq, respectively. RESULTS: The global H3K9me3 level decreases during transformation and its distribution on chromatin is reprogrammed. By combining with TCGA data, we identified 67 candidate oncogenes, among which five genes are totally novel. Our analysis further links H3K9me3 with transposon activity, and suggests H3K9me3 reduction increases the cell's sensitivity to DNA damage reagents. CONCLUSION: H3K9me3 reduction is possibly related with breast cancer transformation by regulating gene expression and chromatin stability during transformation.

Global histone modification profiling reveals the epigenomic dynamics during malignant transformation in a four-stage breast cancer model.

BACKGROUND: Epigenetic regulation has emerged to be the critical steps for tumorigenesis and metastasis. Multiple histone methyltransferase and demethylase have been implicated as tumor suppressors or oncogenes recently. But the key epigenomic events in cancer cell transformation still remain poorly understood. METHODS: A breast cancer transformation model was established via stably expressing three oncogenes in primary breast epithelial cells. Chromatin immunoprecipitation followed by the next-generation sequencing of histone methylations was performed to determine epigenetic events during transformation. Western blot, quantitative RT-PCR, and immunostaining were used to determine gene expression in cells and tissues. RESULTS: Histones H3K9me2 and me3, two repressive marks of transcription, decrease in in vitro breast cancer cell model and in vivo clinical tissues. A survey of enzymes related with H3K9 methylation indicated that KDM3A/JMJD1A, a demethylase for H3K9me1 and me2, gradually increases during cancer transformation and is elevated in patient tissues. KDM3A/JMJD1A deficiency impairs the growth of tumors in nude mice and transformed cell lines. Genome-wide ChIP-seq analysis reveals that the boundaries of decreased H3K9me2 large organized chromatin K9 modifications (LOCKs) are enriched with cancer-related genes, such as MYC and PAX3. Further studies show that KDM3A/JMJD1A directly binds to these oncogenes and regulates their transcription by removing H3K9me2 mark. CONCLUSIONS: Our study demonstrates reduction of histones H3K9 me2 and me3, and elevation of KDM3A/JMJD1A as important events for breast cancer, and illustrates the dynamic epigenomic mechanisms during breast cancer transformation.

The EZH1-SUZ12 complex positively regulates the transcription of NF-κB target genes through interaction with UXT.

Unlike other members of the polycomb group protein family, EZH1 has been shown to positively associate with active transcription on a genome-wide scale. However, the underlying mechanism for this behavior still remains elusive. Here, we report that EZH1 physically interacts with UXT, a small chaperon-like transcription co-activator. UXT specifically interacts with EZH1 and SUZ12, but not EED. Similar to upon knockdown of UXT, knockdown of EZH1 or SUZ12 through RNA interference in the cell impairs the transcriptional activation of nuclear factor (NF)-κB target genes induced by TNFα. EZH1 deficiency also increases TNFα-induced cell death. Interestingly, chromatin immunoprecipitation and the following next-generation sequencing analysis show that H3K27 mono-, di- and tri-methylation on NF-κB target genes are not affected in EZH1- or UXT-deficient cells. EZH1 also does not affect the translocation of the p65 subunit of NF-κB (also known as RELA) from the cytosol to the nucleus. Instead, EZH1 and SUZ12 regulate the recruitment of p65 and RNA Pol II to target genes. Taken together, our study shows that EZH1 and SUZ12 act as positive regulators for NF-κB signaling and demonstrates that EZH1, SUZ12 and UXT work synergistically to regulate pathway activation in the nucleus.

[Toxicology and bioactivities of CO-releasing molecules based on cobalt complexes].

Complexes containing cobalt and carbon monoxide ligands, CO releasing molecules(CORMs), have the potential of anti-tumor and anti-inflammatory. In this paper, three hybrid CORMs 1-3 were synthesized and tested for their toxicology in vivo and bioactivities. The results suggest that the complexes have a long half-life in the range of 43-53 min; their oral LD(50) to mouse are between 1 500 mg·kg(-1) and 5 000 mg·kg(-1). After the successive administration, complex 1 exhibited a toxic activity in rats' liver, and induced an injury to liver cells. Complex 1 had a strong growth inhibition activity(IC(50) 36.20 µmol·L(-1) and 39.25 µmol·L(-1)) in both He La cells and Hep G2 cells, complex 2 displayed a lower activity in the inhibition of He La cells proliferation than the control 5-FU(IC(50) 114.19 µmol·L(-1)), but had a higher activity in the inhibition of Hep G2 cells than the control 5-FU(IC(50) 171.34 µmol·L(-1)). The anti-inflammatory study suggests that all of them reduce intracellular nitrite level, complexes 1 and 2 have a stronger activity than complex 3. Their anti-inflammatory activity attributes to the CO molecules of the CORMs, which was confirmed by comparison with the corresponding ligand.

A novel prognostic score for acute-on-chronic hepatitis B liver failure / 华中科技大学学报（医学）（英德文版）

Patients with acute-on-chronic hepatitis B liver failure (HBV-ACLF) show high morbidity and mortality. Independent prognostic predictors of short-term HBV-ACLF mortality include the Child-Turcotte-Pugh (CTP) score, the model for end-stage liver disease (MELD) score, other MELD-based indices and the dynamic changes in these indices. The aims of this study were to evaluate the existing prognostic scores in a large cohort of HBV-ACLF patients and create a new predictive model. We retrospectively reviewed 392 HBV-ACLF patients from December 2008 to November 2011 and evaluated their 3-month survival. The predictive accuracy of CTP, MELD and MELD-based indices and the dynamic changes in the MELD-related scores (Δ scoring systems) upon admission and after two weeks of treatment were compared using the area under the receiver operating characteristic (ROC) curve method. Life-threatening factors and a series of bio-clinical parameters were studied by univariate and multivariate analyses. Among the existing scores, MELD had the best predictive ability. However, our new regression model provided an area under the curve of 0.930 ± 0.0161 (95% CI: 0.869 to 0.943), which was significantly larger than that obtained with the MELD score at admission and after two weeks of treatment as well as with the dynamic changes of the MELD score (0.819, 0.921, and 0.826, respectively) (Z=3.542, P=0.0004). In a large cohort of patients retrospectively reviewed for this study, our prognostic model was superior to the MELD score and is, therefore, a promising predictor of short-term survival in patients with HBV-ACLF.

A novel prognostic score for acute-on-chronic hepatitis B liver failure / 华中科技大学学报（医学）（英德文版）

Patients with acute-on-chronic hepatitis B liver failure (HBV-ACLF) show high morbidity and mortality. Independent prognostic predictors of short-term HBV-ACLF mortality include the Child-Turcotte-Pugh (CTP) score, the model for end-stage liver disease (MELD) score, other MELD-based indices and the dynamic changes in these indices. The aims of this study were to evaluate the existing prognostic scores in a large cohort of HBV-ACLF patients and create a new predictive model. We retrospectively reviewed 392 HBV-ACLF patients from December 2008 to November 2011 and evaluated their 3-month survival. The predictive accuracy of CTP, MELD and MELD-based indices and the dynamic changes in the MELD-related scores (Δ scoring systems) upon admission and after two weeks of treatment were compared using the area under the receiver operating characteristic (ROC) curve method. Life-threatening factors and a series of bio-clinical parameters were studied by univariate and multivariate analyses. Among the existing scores, MELD had the best predictive ability. However, our new regression model provided an area under the curve of 0.930±0.0161 (95% CI: 0.869 to 0.943), which was significantly larger than that obtained with the MELD score at admission and after two weeks of treatment as well as with the dynamic changes of the MELD score (0.819, 0.921, and 0.826, respectively) (Z=3.542, P=0.0004). In a large cohort of patients retrospectively reviewed for this study, our prognostic model was superior to the MELD score and is, therefore, a promising predictor of short-term survival in patients with HBV-ACLF.

[Toxicology and tissue distribution of Ruthenium (II) CO-releasing molecules and its interaction with endogenous substances].

Carbon monoxide has been proved to be an important signal molecule in body. Transition metal carbonyl compounds are solidified form of carbon monoxide. Numerous studies have shown that Ruthenium carbonyl carbon monoxide releasing molecules have a strong pharmacological activity. In this paper, five Ruthenium (II) carbonyl CORMs 1-5 were synthesized and their toxicology, tissue distribution and interaction with blood endogenous substances were investigated. The results showed CORMs' IC50 to fibroblasts are ranged from 212.9 to 2089.2 micromol x L(-1). Their oral LD50 to mouse is between 800 to 1600 mg x kg(-1). After repeated administration, CORMs 1 and CORMs 5 haven't shown an obvious influence to rats' liver and kidney function, but caused the injury to liver and kidney cells. The in vivo distribution result revealed the majority of CORMs were distributed in blood, liver and kidney, only a small part of CORMs distributed in lung, heart and spleen. They could scarcely cross the blood-brain barrier and distribute to brain. The non-CO ligands in structure have an obvious relevance to their in vivo absorption and distribution. Interestingly, CORMs could enhance the fluorescence of bovine serum albumin, and this enhancement was in direct proportion with the concentration of CORMs. Under different conditions, interaction of CORMs with glutathione got different type of products, one is Ruthenium (II) tricarbonyl complexes, and Ruthenium (II) dicarbonyl complexes.

Normal-phase HPLC enantioseparation of novel chiral metal tetrahedrane-type clusters on an amylose-based chiral stationary phase.

In the present work, an amylose tris(3,5-dimethylphenylcarbamate) (ADMPC) chiral stationary phase (CSP) was prepared by coating ADMPC on small-particle silica gel. This ADMPC-CSP was for the first time successfully applied to separate a series of novel chiral metal tetrahedrane-type clusters. Furthermore, the influence of a mobile-phase modifier (various alcohols added in the mobile phase), including its concentration and structure, and the structures of the clusters on the chiral separation and retention was investigated. The results suggest that not only the structure and concentration of alcohol in the mobile phase, but also the subtle structural differences in racemate can have a pronounced effect on the enantiomeric separation and retention.