The methylated β-cyclodextrins derived optically active polymers are firs synthesized through asymmetric polymerization of N-diphenylmethyl maleimide with lithium salt of heptakis(2,6-O-dimethyl) β-cyclodextrin (DM-...The methylated β-cyclodextrins derived optically active polymers are firs synthesized through asymmetric polymerization of N-diphenylmethyl maleimide with lithium salt of heptakis(2,6-O-dimethyl) β-cyclodextrin (DM-β-CD) as an initiator. The resulting polymers show negative specific rotation which is opposite in sign to that of DM-β-CD. The asymmetric induction is further confirmed by circular dichroism. The structure is characterized by IR and NMR spectroscopies展开更多
The inclusion interaction between three types of methylated-β-cyclodextrins (Me-β-CDs) and albendazole (ABZ) was studied by spectrofluorimetry. The result showed that Me-β-CDs reacted with ABZ to form an inclus...The inclusion interaction between three types of methylated-β-cyclodextrins (Me-β-CDs) and albendazole (ABZ) was studied by spectrofluorimetry. The result showed that Me-β-CDs reacted with ABZ to form an inclusion complex, 1: 1 stoichiometry for Me- β-CDs-ABZ complex was established and its association constant have been determined from fluorescence data by Benesi- Hildebrand's method (double reciprocal plots). It was noted that 2,6-DM-β-CD exhibited stronger binding ability than other Me-β- CDs. Based on the significant enhancement of fluorescence intensity of inclusion complex, a simple and highly sensitive fluorimetric method is proposed for the determination of ABZ in the presence of 2,6-DM-β-CD. The proposed method was successfully applied to the determination of ABZ in tablets and human urine.展开更多
Bio-based cyclodextrins(CDs)are a common research object in supramolecular chemistry.The special cavity structure of CDs can form supramolecular self-assemblies such as vesicles and microcrystals through weak interact...Bio-based cyclodextrins(CDs)are a common research object in supramolecular chemistry.The special cavity structure of CDs can form supramolecular self-assemblies such as vesicles and microcrystals through weak interaction with guest molecules.The different forms of supramolecular self-assemblies can be transformed into each other under certain conditions.The regulation of supramolecular self-assembly is not only helpful to understand the self-assembly principle,but also beneficial to its application.In the present study,the self-assembly behavior of epoxy-β-cyclodextrin(EP-β-CD)and mixed anionic and cationic surfactant system(sodium dodecyl sulfate/dodecyltrimethylammonium bromide,SDS/DTAB)in aqueous solution was studied.Morphological and particle size characterization found that the SDS/DTAB@EP-β-CD complex,as the basic building unit,self-assembled into worm-like micelles at lower temperatures and vesicles at higher temperatures.Nuclear magnetic resonance(NMR)and Fourier transform infrared spectroscopy(FT-IR)analysis revealed that the driving force for the formation of vesicles and worm-like micelles was the hydrogen bonds between EP-β-CD molecules,while water molecules played an important role in promoting vesicle formation between SDS/DTAB@EP-β-CD units.Herein,the mechanism of the morphologic transformation of SDS/DTAB@EP-β-CD supramolecular aggregates induced by temperature was elucidated by exploring the self-assembly process,which may provide an excellent basis for the development of delivery carriers.展开更多
Salsolinol(1-methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline,Sal)is a catechol isoquinoline that causes neurotoxicity and shares structural similarity with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine,an environme...Salsolinol(1-methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline,Sal)is a catechol isoquinoline that causes neurotoxicity and shares structural similarity with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine,an environmental toxin that causes Parkinson's disease.However,the mechanism by which Sal mediates dopaminergic neuronal death remains unclear.In this study,we found that Sal significantly enhanced the global level of N~6-methyladenosine(m~6A)RNA methylation in PC12 cells,mainly by inducing the downregulation of the expression of m~6A demethylases fat mass and obesity-associated protein(FTO)and alk B homolog 5(ALKBH5).RNA sequencing analysis showed that Sal downregulated the Hippo signaling pathway.The m~6A reader YTH domain-containing family protein 2(YTHDF2)promoted the degradation of m~6A-containing Yes-associated protein 1(YAP1)mRNA,which is a downstream key effector in the Hippo signaling pathway.Additionally,downregulation of YAP1 promoted autophagy,indicating that the mutual regulation between YAP1 and autophagy can lead to neurotoxicity.These findings reveal the role of Sal on m~6A RNA methylation and suggest that Sal may act as an RNA methylation inducer mediating dopaminergic neuronal death through YAP1 and autophagy.Our results provide greater insights into the neurotoxic effects of catechol isoquinolines compared with other studies and may be a reference for assessing the involvement of RNA methylation in the pathogenesis of Parkinson's disease.展开更多
BACKGROUND The methylated septin 9(mSEPT9) assay was the first blood-based test approved by the United States Food and Drug Administration as a colorectal screening test.However, the diagnostic and prognostic role of ...BACKGROUND The methylated septin 9(mSEPT9) assay was the first blood-based test approved by the United States Food and Drug Administration as a colorectal screening test.However, the diagnostic and prognostic role of preoperative mSEPT9 for colorectal cancer(CRC) in Chinese patients is still unknown.AIM To improve the understanding of diagnostic and prognostic factors, serum m SEPT9 was detected in Chinese CRC patients.METHODS A retrospective analysis of 354 cases, of which 300 had CRC and 54 were normal,was performed in China. Patients' characteristics, treatments, and laboratory data, including age, the date of surgery, Union for International Cancer Control(UICC) stages, distant metastasis(M), and so on, were collected. Methylation levels of SEPT9 were quantified by quantitative, methylation-specific polymerase chain reaction before surgery. In addition, the effects of mSEPT9 on the occurrence and prognosis of 330 CRC cases from The Cancer Genome Atlas(TCGA) database were evaluated using bioinformatics analyses. Potential prognostic factors for overall survival(OS) and progression-free survival(PFS)were evaluated by Kaplan-Meier univariate analysis.RESULTSIn Chinese CRC patients, positive mSEPT9 was strongly associated with advanced UICC stages, deeper invasion by the primary tumor, and more distant metastasis. Methylation levels of SEPT9 were stage-dependent and showed a stepwise increase in UICC stages(I–IV), primary tumor categories(T1–T4),regional node categories(N0–N2), and distant metastasis categories(M0–M1).The patients with positive mSEPT9 showed a tendency toward lower PFS. After analyzing TCGA clinical data, the high mSEPT9 group was found to be obviously correlated only with more distant metastasis. The patients with high mSEPT9 levels showed a tendency toward lower OS. Besides, nine meaningful mSEPT9 sites were found to provide guidance for the follow-up studies.CONCLUSION MSEPT9 analysis may add valuable information to current tumor staging. Serum m SEPT9 in Chinese CRC patients appears to offer promising novel prognostic markers and might be considered for monitoring CRC recurrence.展开更多
AIM To discover methylated-differentially expressed genes(MDEGs) in hepatocellular carcinoma(HCC) and to explore relevant hub genes and potential pathways. METHODS The data of expression profiling GSE25097 and methyla...AIM To discover methylated-differentially expressed genes(MDEGs) in hepatocellular carcinoma(HCC) and to explore relevant hub genes and potential pathways. METHODS The data of expression profiling GSE25097 and methylation profiling GSE57956 were gained from GEO Datasets. We analyzed the differentially methylated genes and differentially expressed genes online using GEO2 R. Functional and enrichment analyses of MDEGs were conducted using the DAVID database. A protein-protein interaction(PPI) network was performed by STRING and then visualized in Cytoscape. Hub genes were ranked by cytoH ubba, and a module analysis of the PPI network was conducted by MCODE in Cytoscape software. RESULTS In total, we categorized 266 genes as hypermethylated, lowly expressed genes(Hyper-LGs) referring to endogenous and hormone stimulus, cell surface receptor linked signal transduction and behavior. In addition, 161 genes were labelled as hypomethylated, highly expressed genes(Hypo-HGs) referring to DNA replication and metabolic process, cell cycle and division. Pathway analysis illustrated that Hyper-LGs were enriched in cancer, Wnt, and chemokine signalling pathways, while Hypo-HGs were related to cell cycle and steroid hormone biosynthesis pathways. Based on PPI networks, PTGS2, PIK3 CD, CXCL1, ESR1, and MMP2 were identified as hub genes for Hyper-LGs, and CDC45, DTL, AURKB, CDKN3, MCM2, and MCM10 were hub genes for Hypo-HGs by combining six ranked methods of cytoH ubba. CONCLUSION In the study, we disclose numerous novel genetic and epigenetic regulations and offer a vital molecular groundwork to understand the pathogenesis of HCC. Hub genes, including PTGS2, PIK3 CD, CXCL1, ESR1, MMP2, CDC45, DTL, AURKB, CDKN3, MCM2, and MCM10, can be used as biomarkers based on aberrant methylation for the accurate diagnosis and treatment of HCC.展开更多
Aim: To investigate the methylation status of the deleted in azoospermia 1(DAZ1) gene promoter region in different cell types. Methods: Using CpG island Searcher software, a CpG island was found in the promoter re...Aim: To investigate the methylation status of the deleted in azoospermia 1(DAZ1) gene promoter region in different cell types. Methods: Using CpG island Searcher software, a CpG island was found in the promoter region of the DAZ1 gene. The methylation status of this region was analyzed in sperm and leukocytes by bisulfited sequencing. Results: The methylation status of the CpG island in the DAZ1 gene promoter region differed in leukocytes and sperm: it was methylated in leukocytes, but unmethylated in sperm. Conclusion: A differentially methylated region of the DAZ1 gene exists in spermatic and somatic cells, suggesting that methylation of this region may regulate DAZ1 gene expression in different tissues. (Asian J Androl 2006 Jan; 8:61-67 )展开更多
Identifying sensitive and specific biomarkers for early detection of cancer is immensely imperative for early diagnosis and treatment and better clinical outcome of cancer patients. This study aimed to construct a spe...Identifying sensitive and specific biomarkers for early detection of cancer is immensely imperative for early diagnosis and treatment and better clinical outcome of cancer patients. This study aimed to construct a specific DNA methylation pattern of cancer suppressor genes and explore the feasibility of applying cell-free DNA based methylation as a biomarker for early diagnosis of esophageal squamous cell carcinoma(ESCC). We recruited early stage ESCC patients from Yangzhong County, China. The Illumina Infinium 450 K Methylation BeadChip was used to construct a genome-wide DNA methylation profile. Then, differentiated genes were selected for the validation study using the Sequenom MassARRAY platform. The frequency of methylation was compared between cancer tissues, matched cell-free DNAs and normal controls. The specific methylation profiles were constructed, and the sensitivity and specificity were calculated. Seven CG sites in three genes CASZ1, CDH13 and ING2 were significantly hypermethylated in ESCC as compared with normal controls. A significant correlation was found between the methylation of DNA extracted from cancer tissues and matched plasma cell-free DNA, either for individual CG site or for cumulative methylation analysis. The sensitivity and specificity reached 100% at an appropriate cut-point using these specific methylation biomarkers. This study revealed that aberrant DNA methylation is a promising biomarker for molecular diagnosis of esophageal cancer. Hypermethylation of CASZ1,CDH13 and ING2 detected in plasma cell-free DNA can be applied as a potential noninvasive biomarker for diagnosis of esophageal cancer.展开更多
AIM: To investigate the feasibility of detecting hypermethylated secreted frizzled-related protein 2 (SFRP2) gene in fecal DNA as a non-invasive screening tool for colorectal cancer (CRC). METHODS: Fluorescence-based ...AIM: To investigate the feasibility of detecting hypermethylated secreted frizzled-related protein 2 (SFRP2) gene in fecal DNA as a non-invasive screening tool for colorectal cancer (CRC). METHODS: Fluorescence-based real-time PCR assay (MethyLight) was performed to analyze SFRP2 gene promoter methylation status in a blinded fashion in tumor tissues and in stool samples taken from 69 CRC patients preoperatively and at the 9th postoperative day,34 patients with adenoma ≥ 1 cm,26 with hyperplastic polyp,and 30 endoscopically normal subjects. Simultaneously the relationship between hypermethylation of SFRP2 gene and clinicopathological features was analyzed. RESULTS: SFRP2 gene was hypermethylated in 91.3% (63/69) CRC,79.4% (27/34) and 53.8% (14/26) adenoma and hyperplastic polyp tissues,and in 87.0% (60/69),61.8% (21/34) and 42.3% (11/26) of corresponding fecal samples,respectively. In contrast,no methylated SFRP2 gene was detected in mucosal tissues of normal controls,while two cases of matched fecal samples from normal controls were detected with hypermethylated SFRP2. A significant decrease (P < 0.001) in the rate of hypermethylated SFRP2 gene was detected in the postoperative (8.7%,6/69) fecal samples as compared with the preoperative fecal samples (87%,60/69) of CRC patients. Moreover,no significant associations were observed between SFRP2 hypermethylation and clinicopathological features including sex,age,tumor stage,site,lymph node status and histological grade,etc. CONCLUSION: Hypermethylation of SFRP2 gene in fecal DNA is a novel molecular biomarker of CRC and carries a high potential for the remote detection of CRC and premalignant lesions as noninvasive screening method.展开更多
To screen clinically relevant microRNAs (miRNAs) silenced by DNA methylation in human hepatocellular carcinoma (HCC).METHODSKnockdown of DNA methyltransferases (DNMTs) using siRNAs and miRNA profiling in HCC cell line...To screen clinically relevant microRNAs (miRNAs) silenced by DNA methylation in human hepatocellular carcinoma (HCC).METHODSKnockdown of DNA methyltransferases (DNMTs) using siRNAs and miRNA profiling in HCC cell lines were performed to identify DNA hypermethylation-mediated miRNA downregulation. Confirmation using individual quantitative real-time PCR (qRT-PCR) assays was then performed followed by DNA methylation quantification at the promoter of the miRNA genes. Quantification of DNA methylation and miRNA expression was then performed in primary HCC tumor samples and related with clinicopathological variables.RESULTSmiRNA profiling after DNMT knockdown in HCC cell lines revealed upregulation of miR-23, miR-25 and miR-183. After qRT-PCR confirmation and CpG island methylation quantification of these miRNAs in cell lines, further analysis in primary HCC specimens showed that hsa-miR-183 is hypermethylated in 30% of HCC (n = 40). Expression of mature miR-183 showed an inverse correlation with DNA methylation levels. In HCC cells, DNMT knockdown and 5-aza-2’-deoxycytidine treatment reduced methylation and stimulated expression of miR-183. In HCC patients, hypermethylation at hsa-miR-183 promoter significantly correlates with poor survival (log-rank test P = 0.03). DNA methylation analysis in healthy liver, benign liver tumors (hepatocellular adenoma and focal nodular hyperplasia) and their corresponding adjacent tissues showed absence of hypermethylation supporting the notion that aberrant methylation at hsa-miR-183 is specific for the malignant transformation of hepatocytes.CONCLUSIONOur data indicate that hypermethylation of hsa-miR-183 is a frequent event in HCC and potentially useful as a novel surrogate diagnostic and prognostic marker.展开更多
The inclusion-complex of CD-MCP (β-cyclodextrin (β-CD) including 1-methylcyclopropene (1-MCP)) was prepared and characterized. Basing on programmed-heating procedure and weight-temperature analysis, as well as...The inclusion-complex of CD-MCP (β-cyclodextrin (β-CD) including 1-methylcyclopropene (1-MCP)) was prepared and characterized. Basing on programmed-heating procedure and weight-temperature analysis, as well as the application of Satava-Sestak's, Ozawa's and Kissinger's methods, the mechanism and kinetics of thermal dissociation of this inclusion complex were studied. An additional mass loss is found at 170-180℃. The mechanism of thermal dissociation of CD-MCP is dominated by a one-dimensional random nucleation and subsequent growth process (A2/3). The activation energy Es and the pre-exponential factor AS for the process are 102.14 kJ/mol and 3.63×10^10s^-1, respectively. This ES value shows that there is no strong chemical intere, ctions between β-CD and 1-MC;P,展开更多
Studies have shown that aberrant DNA methylation of apoptotic protease activating factor-1(APAF1) is an important epigenetic mechanism of gene regulation in the progression of bladder cancer.In this article,we have ...Studies have shown that aberrant DNA methylation of apoptotic protease activating factor-1(APAF1) is an important epigenetic mechanism of gene regulation in the progression of bladder cancer.In this article,we have proved that procaine,an inhibitor of DNA methyltransferases,could inhibit the proliferation of T24 and 5637 human bladder cancer cells by inducing their apoptosis.The mechanism studies reveal that procaine could induce demethylation of APAF1 gene in T24 or 5637 cells,subsequently activating caspase-3/9.It was also shown that the serum soluble fas ligand(sFasL) was activated,and the expression of matrix metallopeptidase 9(MMP-9) was down-regulated.Procaine seems to induce cell death by different pathways,and it might be used as a potential agent for bladder cancer treatment.展开更多
This paper describes a triple-transforming gel system (gel-sol-gel') for the first time, which is a thermo-responsive and multi- component organogel prepared by β-cyclodextrin (β-CD), diphenylamine (DPA) and ...This paper describes a triple-transforming gel system (gel-sol-gel') for the first time, which is a thermo-responsive and multi- component organogel prepared by β-cyclodextrin (β-CD), diphenylamine (DPA) and lithium chloride (LiCl) in N,N-dimethyla- cetamide (DMAC) in a suitable proportion based on the supramolecular interactions. In the triple-transfomaing gel system, a gel (gel A) could be formed by β-CD, DPA and LiCl in DMAC at room temperature based on stirring, then the gel could transform into a clear solution based on heating, and then the other gel (gel B) can be formed at a relatively high temperature (Tget, the gelation temperature by heating). The two gel states in the triple-transforming gel system have different microstructures. This gel system was characterized by OM, SEM, IR and theology.展开更多
Objective: Kaiso is upregulated in many cancers and proposed to bind with both methylated- and unmethylated-DNA in the nucleus as a transcriptional repressor. The objective is to define its subcellnlar localization i...Objective: Kaiso is upregulated in many cancers and proposed to bind with both methylated- and unmethylated-DNA in the nucleus as a transcriptional repressor. The objective is to define its subcellnlar localization in vivo and exact binding DNA sequences in cells. Methods: Compartmentalization of exogenous Kaiso in cells was tracked with enhanced green fluorescence protein (EGFP) tag. The endogenous Kaiso expression in gastric carcinoma tissue was examined with immunohistochemical staining. Kaiso-DNA binding was tested using electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation assay (CHIP). Results: Kaiso mainly localized in the nucleus of cancer and stromal cells in vivo, but remained in the cytoplasm of cultured cells. Most importantly, nuclear Kaiso can bind with the methylated-CGCG- containing sequence in the CDKN2A promoter, but not with the hydroxymethylated-CGCG sequence in HCT116 cells. Conclusions: Kaiso locates mainly in the nucleus in vivo where it binds with the methylated-CGCG sequences, but does not bind with the hydroxymethylated-CGCG sequences.展开更多
DNA methylation is one of the epigenetic phenomena which can be transferred to the offspring by cell division in the evolution of organisms. The epigenetic regulation accompanied by gene expression can be found direct...DNA methylation is one of the epigenetic phenomena which can be transferred to the offspring by cell division in the evolution of organisms. The epigenetic regulation accompanied by gene expression can be found directly in the phenotype of haploidy plants. DNA cytosine methylation at the 5'-CpCpGpG sites of haploid, Shuhui 527, Shuhui 363 and their hybrids was analyzed by methylation sensitive amplification polymorphism (MSAP) method. There were 765 DNA methylated sites detected and the methylation level was lower in hybrids than parents. Meanwhile, the different bands between hybrids and parents were analyzed and two types of methylated sites were detected, of which one inherited from haploid, and the other did not. The biological functions of genes related to methylated sites involved in cell structure, metabolize and response factor. Therefore, DNA methylated modifications can activate and silence the genes and play an important role in plant growth, development and evolution.展开更多
Objective:To investigate the feasibility of the combination of detecting hypermethylated secreted frizzled-related protein 1 (SFRP1) and secreted frizzled-related protein 2(SFRP2) in feces as a panel of biomarker...Objective:To investigate the feasibility of the combination of detecting hypermethylated secreted frizzled-related protein 1 (SFRP1) and secreted frizzled-related protein 2(SFRP2) in feces as a panel of biomarkers for colorectal cancer(CRC) screening. Methods: Methylation-specific PCR(MSP) was performed to analyze methylation status of SFRP1 and SFRP2 in a blinded fashion in tumor tissues and in matched stool samples from 39 patients with primary CRC, 34 patients with adenomas, 17 patients with hyperplastic polyps and 20 endoscopically normal subjects as normal controls. Simultaneously we analyzed the correlation of hypermethylated SFRP1 and SFRP2 with the clinicopathological features of CRC. Results:Hypermethylated SFRP1 was detected in 92.3%, 76.5%, 47.1% of tissue samples and in 89.7%, 64.7%, 35.3% of matched fecal samples from CRC, adenoma and hyperplastic polyp, respectively. Hypermethylated SFRP2 was detected in 87.2%, 67.6%, 35.3% of tissue samples and in 82.1%, 55.9%, 29.4% of matched fecal samples from CRC, adenoma and hyperplastic polyp, respectively. Of these two genes, at least one hypermethylated was 94.9%, 82.4%, 52.9% in tissue samples and 92.3%,73.5%, 47.1% in matched fecal samples from CRC, adenoma and hyperplastic polyp, respectively. In contrast, no hypermethylated SFRP1 and SFRP2 were detected in mucosa tissues of normal controls, only 2 cases of fecal samples was detected with hypermethylated SFRP1 and another 1 case was detected with hypermethylated SFRP2. Moreover, no significant associations were observed between hypermethylated SFRP1,SFRP2 and clinicopathological features of CRC. Conclusion: Hypermethylation of SFRP1 and SFRP2 in feces are novel epigenetic biomarkers of CRC and carded high potential for the remote detection of CRC as non-invasive screening method, and combined analysis of hypermethylated SFRP1 and SFRP2 in fecal could further increase the detection rate of CRC and premalignant lesions.展开更多
AIM: To explore epigenetic changes in the gene encod- ing X chromosome-linked inhibitor of apoptosis-associ- ated factor 1 (XAF1) during esophageal carcinogenesis. METHODS: Methylation status of XAF1 was detected ...AIM: To explore epigenetic changes in the gene encod- ing X chromosome-linked inhibitor of apoptosis-associ- ated factor 1 (XAF1) during esophageal carcinogenesis. METHODS: Methylation status of XAF1 was detected by methylation-specific polymerase chain reaction (MSP) in four esophageal cancer cell lines (KYSE30, KYSE70, BICl and partially methylated in TE3 cell lines), nine cases of normal mucosa, 72 cases of pri- mary esophageal cancer and matched adjacent tissue. XAF1 expression was examined by semi-quantitative reverse transcriptional polymerase chain reaction and Western blotting before and after treatment with 5-aza- deoxycytidine (5-aza-dc), a demethylating agent. To investigate the correlation of XAF1 expression and methylation status in primary esophageal cancer, immu- nohistochemistry for XAF1 expression was performed in 32 cases of esophageal cancer and matched adjacent tissue. The association of methylation status and clini-copathological data was analyzed by logistic regression. RESULTS: MSP results were as follows: loss of XAF1 expression was found in three of four esophageal cell lines with promoter region hypermethylation (com- pletely methylated in KYSE30, KYSE70 and BIC1 cell lines and partially in TE3 cells); all nine cases of normal esophageal mucosa were unmethylated; and 54/72 (75.00%) samples from patients with esophageal can- cer were methylated, and 25/72 (34.70%) matched adjacent tissues were methylated (75.00% vs 34,70%, z2 = 23.5840, P = 0.000). mRNA level of XAF1 mea- sured with semi-quantitative reverse transcription poly- merase chain reaction was detectable only in TE3 cells, and no expression was detected in KYSE30, KYSE70 or BIC1 cells. Protein expression was not observed in KYSE30 cells by Western blotting before treatment with 5-aza-dc. After treatment, mRNA level of XAF1 was detectable in KYSE30, KYSE70 and BIC1 cells. Protein expression was detected in KYSE30 after treatment with 5-aza-dc. Immunohistochemistry was performed on 32 cases of esophageal cancer and adjacent tissue, and demonstrated XAF1 in the nucleus and cytoplasm. XAF1 staining was found in 20/32 samples of adjacent normal tissue but was present in only 8/32 samples of esophageal cancer tissue (Z2= 9.143, P = 0.002). XAF1 expression was decreased in cancer samples compared with adjacent tissues. In 32 cases of esophageal can- cer, 24/32 samples were methylated, and 8/32 esopha- geal cancer tissues were unmethylated. XAF1 staining was found in 6/8 samples of unmethylated esophageal cancer and 2/24 samples of methylated esophageal cancer tissue. XAF1 staining was inversely correlated with XAF1 promoter region methylation (Fisher's exact test, P = 0.004). Regarding methylation status and clinicopathological data, no significant differences were found in sex, age, tumor size, tumor stage, or metas- tasis with respect to methylation of XAF1 for the 72 tis- sue samples from patients with esophageal cancer. CONCLUSION: XAF1 is frequently methylated in eso- phageal cancer, and XAF1 expression is regulated by promoter region hypermethylation.展开更多
Novel insulin-loaded nanoparticles based on hydroxypropyl-β-cyclodextrin modified carboxymethyl chitosan(CMC-HP-β-CD) were prepared to improve the oral bioavailability of insulin. The CMC-HP-β-CD was characterize...Novel insulin-loaded nanoparticles based on hydroxypropyl-β-cyclodextrin modified carboxymethyl chitosan(CMC-HP-β-CD) were prepared to improve the oral bioavailability of insulin. The CMC-HP-β-CD was characterized by FT-IR spectroscopy and 1H-NMR spectra. The insulin-loaded nanoparticles were prepared through crosslinking with calcium ions, and the morphology and size of the prepared nanoparticles were characterized by transmission electron microscopy(TEM) and dynamic light scattering(DLS). Cumulative release in vitro study was performed respectively in simulated gastric medium fluid(SGF, p H=1.2), simulated intestinal fluid(SIF, p H=6.8) and simulated colonic fluid(SCF, p H=7.4). The encapsulation efficiency of insulin was up to 87.14 ± 4.32% through high-performance liquid chromatography(HPLC). Statistics indicated that only 15% of the encapsulated insulin was released from the CMC-HP-β-CD nanoparticles in 36 h in SGF, and about 50% of the insulin could be released from the nanoparticles in SIF, whereas more than 80% was released in SCF. In addition, the solution containing insulin nanoparticles could effectively reduce the blood glucose level of diabetic mice. The cytotoxicity test showed that the samples had no cytotoxicity. CMC-HP-β-CD nanoparticles are promising candidates as potential carriers in oral insulin delivery systems.展开更多
A cationic cyclodextrin derivative 6-O-(hydroxypropyltrimethylammonia)-β-cyclodextrin (GTA-β-CD) with low degree of substitution was prepared through a convenient method in solid phase. The product could be used...A cationic cyclodextrin derivative 6-O-(hydroxypropyltrimethylammonia)-β-cyclodextrin (GTA-β-CD) with low degree of substitution was prepared through a convenient method in solid phase. The product could be used as a valuable chiral selector in the capillary electrophoresis (CE) separation of some acidic drug enantiomers such as naproxen, ofloxacin, ibuprofen and warfarin.展开更多
文摘The methylated β-cyclodextrins derived optically active polymers are firs synthesized through asymmetric polymerization of N-diphenylmethyl maleimide with lithium salt of heptakis(2,6-O-dimethyl) β-cyclodextrin (DM-β-CD) as an initiator. The resulting polymers show negative specific rotation which is opposite in sign to that of DM-β-CD. The asymmetric induction is further confirmed by circular dichroism. The structure is characterized by IR and NMR spectroscopies
基金the Natural Science Foundation of Shanxi(No.2007011027)
文摘The inclusion interaction between three types of methylated-β-cyclodextrins (Me-β-CDs) and albendazole (ABZ) was studied by spectrofluorimetry. The result showed that Me-β-CDs reacted with ABZ to form an inclusion complex, 1: 1 stoichiometry for Me- β-CDs-ABZ complex was established and its association constant have been determined from fluorescence data by Benesi- Hildebrand's method (double reciprocal plots). It was noted that 2,6-DM-β-CD exhibited stronger binding ability than other Me-β- CDs. Based on the significant enhancement of fluorescence intensity of inclusion complex, a simple and highly sensitive fluorimetric method is proposed for the determination of ABZ in the presence of 2,6-DM-β-CD. The proposed method was successfully applied to the determination of ABZ in tablets and human urine.
基金China Postdoctoral Science Foundation(2020M681125)National Natural Science Foundation of China(32272254,31901618)Collaborative Innovation Center of Fragrance Flavour and Cosmetics.
文摘Bio-based cyclodextrins(CDs)are a common research object in supramolecular chemistry.The special cavity structure of CDs can form supramolecular self-assemblies such as vesicles and microcrystals through weak interaction with guest molecules.The different forms of supramolecular self-assemblies can be transformed into each other under certain conditions.The regulation of supramolecular self-assembly is not only helpful to understand the self-assembly principle,but also beneficial to its application.In the present study,the self-assembly behavior of epoxy-β-cyclodextrin(EP-β-CD)and mixed anionic and cationic surfactant system(sodium dodecyl sulfate/dodecyltrimethylammonium bromide,SDS/DTAB)in aqueous solution was studied.Morphological and particle size characterization found that the SDS/DTAB@EP-β-CD complex,as the basic building unit,self-assembled into worm-like micelles at lower temperatures and vesicles at higher temperatures.Nuclear magnetic resonance(NMR)and Fourier transform infrared spectroscopy(FT-IR)analysis revealed that the driving force for the formation of vesicles and worm-like micelles was the hydrogen bonds between EP-β-CD molecules,while water molecules played an important role in promoting vesicle formation between SDS/DTAB@EP-β-CD units.Herein,the mechanism of the morphologic transformation of SDS/DTAB@EP-β-CD supramolecular aggregates induced by temperature was elucidated by exploring the self-assembly process,which may provide an excellent basis for the development of delivery carriers.
基金supported by the National Natural Science Foundation of China,Nos.82271283(to XC),91854115(to JW),31970044(to JW)the Natural Science Foundation of Beijing,No.7202001(to XC)the Scientific Research Project of Beijing Educational Committee,No.KM202010005022(to XC)。
文摘Salsolinol(1-methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline,Sal)is a catechol isoquinoline that causes neurotoxicity and shares structural similarity with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine,an environmental toxin that causes Parkinson's disease.However,the mechanism by which Sal mediates dopaminergic neuronal death remains unclear.In this study,we found that Sal significantly enhanced the global level of N~6-methyladenosine(m~6A)RNA methylation in PC12 cells,mainly by inducing the downregulation of the expression of m~6A demethylases fat mass and obesity-associated protein(FTO)and alk B homolog 5(ALKBH5).RNA sequencing analysis showed that Sal downregulated the Hippo signaling pathway.The m~6A reader YTH domain-containing family protein 2(YTHDF2)promoted the degradation of m~6A-containing Yes-associated protein 1(YAP1)mRNA,which is a downstream key effector in the Hippo signaling pathway.Additionally,downregulation of YAP1 promoted autophagy,indicating that the mutual regulation between YAP1 and autophagy can lead to neurotoxicity.These findings reveal the role of Sal on m~6A RNA methylation and suggest that Sal may act as an RNA methylation inducer mediating dopaminergic neuronal death through YAP1 and autophagy.Our results provide greater insights into the neurotoxic effects of catechol isoquinolines compared with other studies and may be a reference for assessing the involvement of RNA methylation in the pathogenesis of Parkinson's disease.
基金Supported by the National Natural Science Foundation of China,No.81803035,No.81703036,and No.81572946the China Postdoctoral Science Foundation,No.2017M610510the Youth Fund of Xiangya Hospital,No.2017Q17
文摘BACKGROUND The methylated septin 9(mSEPT9) assay was the first blood-based test approved by the United States Food and Drug Administration as a colorectal screening test.However, the diagnostic and prognostic role of preoperative mSEPT9 for colorectal cancer(CRC) in Chinese patients is still unknown.AIM To improve the understanding of diagnostic and prognostic factors, serum m SEPT9 was detected in Chinese CRC patients.METHODS A retrospective analysis of 354 cases, of which 300 had CRC and 54 were normal,was performed in China. Patients' characteristics, treatments, and laboratory data, including age, the date of surgery, Union for International Cancer Control(UICC) stages, distant metastasis(M), and so on, were collected. Methylation levels of SEPT9 were quantified by quantitative, methylation-specific polymerase chain reaction before surgery. In addition, the effects of mSEPT9 on the occurrence and prognosis of 330 CRC cases from The Cancer Genome Atlas(TCGA) database were evaluated using bioinformatics analyses. Potential prognostic factors for overall survival(OS) and progression-free survival(PFS)were evaluated by Kaplan-Meier univariate analysis.RESULTSIn Chinese CRC patients, positive mSEPT9 was strongly associated with advanced UICC stages, deeper invasion by the primary tumor, and more distant metastasis. Methylation levels of SEPT9 were stage-dependent and showed a stepwise increase in UICC stages(I–IV), primary tumor categories(T1–T4),regional node categories(N0–N2), and distant metastasis categories(M0–M1).The patients with positive mSEPT9 showed a tendency toward lower PFS. After analyzing TCGA clinical data, the high mSEPT9 group was found to be obviously correlated only with more distant metastasis. The patients with high mSEPT9 levels showed a tendency toward lower OS. Besides, nine meaningful mSEPT9 sites were found to provide guidance for the follow-up studies.CONCLUSION MSEPT9 analysis may add valuable information to current tumor staging. Serum m SEPT9 in Chinese CRC patients appears to offer promising novel prognostic markers and might be considered for monitoring CRC recurrence.
基金Supported by the Liaoning Natural Science Foundation Project,No.20170541039
文摘AIM To discover methylated-differentially expressed genes(MDEGs) in hepatocellular carcinoma(HCC) and to explore relevant hub genes and potential pathways. METHODS The data of expression profiling GSE25097 and methylation profiling GSE57956 were gained from GEO Datasets. We analyzed the differentially methylated genes and differentially expressed genes online using GEO2 R. Functional and enrichment analyses of MDEGs were conducted using the DAVID database. A protein-protein interaction(PPI) network was performed by STRING and then visualized in Cytoscape. Hub genes were ranked by cytoH ubba, and a module analysis of the PPI network was conducted by MCODE in Cytoscape software. RESULTS In total, we categorized 266 genes as hypermethylated, lowly expressed genes(Hyper-LGs) referring to endogenous and hormone stimulus, cell surface receptor linked signal transduction and behavior. In addition, 161 genes were labelled as hypomethylated, highly expressed genes(Hypo-HGs) referring to DNA replication and metabolic process, cell cycle and division. Pathway analysis illustrated that Hyper-LGs were enriched in cancer, Wnt, and chemokine signalling pathways, while Hypo-HGs were related to cell cycle and steroid hormone biosynthesis pathways. Based on PPI networks, PTGS2, PIK3 CD, CXCL1, ESR1, and MMP2 were identified as hub genes for Hyper-LGs, and CDC45, DTL, AURKB, CDKN3, MCM2, and MCM10 were hub genes for Hypo-HGs by combining six ranked methods of cytoH ubba. CONCLUSION In the study, we disclose numerous novel genetic and epigenetic regulations and offer a vital molecular groundwork to understand the pathogenesis of HCC. Hub genes, including PTGS2, PIK3 CD, CXCL1, ESR1, MMP2, CDC45, DTL, AURKB, CDKN3, MCM2, and MCM10, can be used as biomarkers based on aberrant methylation for the accurate diagnosis and treatment of HCC.
文摘Aim: To investigate the methylation status of the deleted in azoospermia 1(DAZ1) gene promoter region in different cell types. Methods: Using CpG island Searcher software, a CpG island was found in the promoter region of the DAZ1 gene. The methylation status of this region was analyzed in sperm and leukocytes by bisulfited sequencing. Results: The methylation status of the CpG island in the DAZ1 gene promoter region differed in leukocytes and sperm: it was methylated in leukocytes, but unmethylated in sperm. Conclusion: A differentially methylated region of the DAZ1 gene exists in spermatic and somatic cells, suggesting that methylation of this region may regulate DAZ1 gene expression in different tissues. (Asian J Androl 2006 Jan; 8:61-67 )
基金supported by the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(grant number 17KJD330002)the Science and Technology Development Fund of Nanjing Medical University(grant number 2017NJMUZD141)the Science and Technology Development Fund of Kangda College of Nanjing Medical University(grant number KD2016KYJJZD007,KD2016KYJJZD008)
文摘Identifying sensitive and specific biomarkers for early detection of cancer is immensely imperative for early diagnosis and treatment and better clinical outcome of cancer patients. This study aimed to construct a specific DNA methylation pattern of cancer suppressor genes and explore the feasibility of applying cell-free DNA based methylation as a biomarker for early diagnosis of esophageal squamous cell carcinoma(ESCC). We recruited early stage ESCC patients from Yangzhong County, China. The Illumina Infinium 450 K Methylation BeadChip was used to construct a genome-wide DNA methylation profile. Then, differentiated genes were selected for the validation study using the Sequenom MassARRAY platform. The frequency of methylation was compared between cancer tissues, matched cell-free DNAs and normal controls. The specific methylation profiles were constructed, and the sensitivity and specificity were calculated. Seven CG sites in three genes CASZ1, CDH13 and ING2 were significantly hypermethylated in ESCC as compared with normal controls. A significant correlation was found between the methylation of DNA extracted from cancer tissues and matched plasma cell-free DNA, either for individual CG site or for cumulative methylation analysis. The sensitivity and specificity reached 100% at an appropriate cut-point using these specific methylation biomarkers. This study revealed that aberrant DNA methylation is a promising biomarker for molecular diagnosis of esophageal cancer. Hypermethylation of CASZ1,CDH13 and ING2 detected in plasma cell-free DNA can be applied as a potential noninvasive biomarker for diagnosis of esophageal cancer.
基金The Grant from Programs of Science and Technology Commission Foundation of Jiangsu Province,No.BS2005036
文摘AIM: To investigate the feasibility of detecting hypermethylated secreted frizzled-related protein 2 (SFRP2) gene in fecal DNA as a non-invasive screening tool for colorectal cancer (CRC). METHODS: Fluorescence-based real-time PCR assay (MethyLight) was performed to analyze SFRP2 gene promoter methylation status in a blinded fashion in tumor tissues and in stool samples taken from 69 CRC patients preoperatively and at the 9th postoperative day,34 patients with adenoma ≥ 1 cm,26 with hyperplastic polyp,and 30 endoscopically normal subjects. Simultaneously the relationship between hypermethylation of SFRP2 gene and clinicopathological features was analyzed. RESULTS: SFRP2 gene was hypermethylated in 91.3% (63/69) CRC,79.4% (27/34) and 53.8% (14/26) adenoma and hyperplastic polyp tissues,and in 87.0% (60/69),61.8% (21/34) and 42.3% (11/26) of corresponding fecal samples,respectively. In contrast,no methylated SFRP2 gene was detected in mucosal tissues of normal controls,while two cases of matched fecal samples from normal controls were detected with hypermethylated SFRP2. A significant decrease (P < 0.001) in the rate of hypermethylated SFRP2 gene was detected in the postoperative (8.7%,6/69) fecal samples as compared with the preoperative fecal samples (87%,60/69) of CRC patients. Moreover,no significant associations were observed between SFRP2 hypermethylation and clinicopathological features including sex,age,tumor stage,site,lymph node status and histological grade,etc. CONCLUSION: Hypermethylation of SFRP2 gene in fecal DNA is a novel molecular biomarker of CRC and carries a high potential for the remote detection of CRC and premalignant lesions as noninvasive screening method.
基金Supported by the Deutsche Forschungsgemeinschaft,No.(DFG) SFB-TRR77 “Liver cancer”(Project B1)
文摘To screen clinically relevant microRNAs (miRNAs) silenced by DNA methylation in human hepatocellular carcinoma (HCC).METHODSKnockdown of DNA methyltransferases (DNMTs) using siRNAs and miRNA profiling in HCC cell lines were performed to identify DNA hypermethylation-mediated miRNA downregulation. Confirmation using individual quantitative real-time PCR (qRT-PCR) assays was then performed followed by DNA methylation quantification at the promoter of the miRNA genes. Quantification of DNA methylation and miRNA expression was then performed in primary HCC tumor samples and related with clinicopathological variables.RESULTSmiRNA profiling after DNMT knockdown in HCC cell lines revealed upregulation of miR-23, miR-25 and miR-183. After qRT-PCR confirmation and CpG island methylation quantification of these miRNAs in cell lines, further analysis in primary HCC specimens showed that hsa-miR-183 is hypermethylated in 30% of HCC (n = 40). Expression of mature miR-183 showed an inverse correlation with DNA methylation levels. In HCC cells, DNMT knockdown and 5-aza-2’-deoxycytidine treatment reduced methylation and stimulated expression of miR-183. In HCC patients, hypermethylation at hsa-miR-183 promoter significantly correlates with poor survival (log-rank test P = 0.03). DNA methylation analysis in healthy liver, benign liver tumors (hepatocellular adenoma and focal nodular hyperplasia) and their corresponding adjacent tissues showed absence of hypermethylation supporting the notion that aberrant methylation at hsa-miR-183 is specific for the malignant transformation of hepatocytes.CONCLUSIONOur data indicate that hypermethylation of hsa-miR-183 is a frequent event in HCC and potentially useful as a novel surrogate diagnostic and prognostic marker.
文摘The inclusion-complex of CD-MCP (β-cyclodextrin (β-CD) including 1-methylcyclopropene (1-MCP)) was prepared and characterized. Basing on programmed-heating procedure and weight-temperature analysis, as well as the application of Satava-Sestak's, Ozawa's and Kissinger's methods, the mechanism and kinetics of thermal dissociation of this inclusion complex were studied. An additional mass loss is found at 170-180℃. The mechanism of thermal dissociation of CD-MCP is dominated by a one-dimensional random nucleation and subsequent growth process (A2/3). The activation energy Es and the pre-exponential factor AS for the process are 102.14 kJ/mol and 3.63×10^10s^-1, respectively. This ES value shows that there is no strong chemical intere, ctions between β-CD and 1-MC;P,
基金Supported by the National Natural Science Foundation of China(Nos.81001298,81241093)the Project of China Postdoctoral Science Foundation(No.20100481058)+2 种基金the High-tech Industrial Development Project of Jilin Province,China(No.20090633)the Specialized Research Fund for the Doctoral Program of Higher Education of China(No.20100061120028)the Scientific Research Foundation of Jilin Province,China(Nos.20080739,200905169)
文摘Studies have shown that aberrant DNA methylation of apoptotic protease activating factor-1(APAF1) is an important epigenetic mechanism of gene regulation in the progression of bladder cancer.In this article,we have proved that procaine,an inhibitor of DNA methyltransferases,could inhibit the proliferation of T24 and 5637 human bladder cancer cells by inducing their apoptosis.The mechanism studies reveal that procaine could induce demethylation of APAF1 gene in T24 or 5637 cells,subsequently activating caspase-3/9.It was also shown that the serum soluble fas ligand(sFasL) was activated,and the expression of matrix metallopeptidase 9(MMP-9) was down-regulated.Procaine seems to induce cell death by different pathways,and it might be used as a potential agent for bladder cancer treatment.
文摘This paper describes a triple-transforming gel system (gel-sol-gel') for the first time, which is a thermo-responsive and multi- component organogel prepared by β-cyclodextrin (β-CD), diphenylamine (DPA) and lithium chloride (LiCl) in N,N-dimethyla- cetamide (DMAC) in a suitable proportion based on the supramolecular interactions. In the triple-transfomaing gel system, a gel (gel A) could be formed by β-CD, DPA and LiCl in DMAC at room temperature based on stirring, then the gel could transform into a clear solution based on heating, and then the other gel (gel B) can be formed at a relatively high temperature (Tget, the gelation temperature by heating). The two gel states in the triple-transforming gel system have different microstructures. This gel system was characterized by OM, SEM, IR and theology.
基金supported by National Basic Research Program of China(Grant No.2011CB504201)
文摘Objective: Kaiso is upregulated in many cancers and proposed to bind with both methylated- and unmethylated-DNA in the nucleus as a transcriptional repressor. The objective is to define its subcellnlar localization in vivo and exact binding DNA sequences in cells. Methods: Compartmentalization of exogenous Kaiso in cells was tracked with enhanced green fluorescence protein (EGFP) tag. The endogenous Kaiso expression in gastric carcinoma tissue was examined with immunohistochemical staining. Kaiso-DNA binding was tested using electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation assay (CHIP). Results: Kaiso mainly localized in the nucleus of cancer and stromal cells in vivo, but remained in the cytoplasm of cultured cells. Most importantly, nuclear Kaiso can bind with the methylated-CGCG- containing sequence in the CDKN2A promoter, but not with the hydroxymethylated-CGCG sequence in HCT116 cells. Conclusions: Kaiso locates mainly in the nucleus in vivo where it binds with the methylated-CGCG sequences, but does not bind with the hydroxymethylated-CGCG sequences.
基金supported by the National Natural Science Foundation of China (Grant Nos. 30771157and 30971618)Science and Technology in Sichuan Province,China (Grant No. 2008JY0094)
文摘DNA methylation is one of the epigenetic phenomena which can be transferred to the offspring by cell division in the evolution of organisms. The epigenetic regulation accompanied by gene expression can be found directly in the phenotype of haploidy plants. DNA cytosine methylation at the 5'-CpCpGpG sites of haploid, Shuhui 527, Shuhui 363 and their hybrids was analyzed by methylation sensitive amplification polymorphism (MSAP) method. There were 765 DNA methylated sites detected and the methylation level was lower in hybrids than parents. Meanwhile, the different bands between hybrids and parents were analyzed and two types of methylated sites were detected, of which one inherited from haploid, and the other did not. The biological functions of genes related to methylated sites involved in cell structure, metabolize and response factor. Therefore, DNA methylated modifications can activate and silence the genes and play an important role in plant growth, development and evolution.
基金supported by the grant from Programs of Science and Technology Commission Foundation of Jiangsu Province(NO.BS2005036)
文摘Objective:To investigate the feasibility of the combination of detecting hypermethylated secreted frizzled-related protein 1 (SFRP1) and secreted frizzled-related protein 2(SFRP2) in feces as a panel of biomarkers for colorectal cancer(CRC) screening. Methods: Methylation-specific PCR(MSP) was performed to analyze methylation status of SFRP1 and SFRP2 in a blinded fashion in tumor tissues and in matched stool samples from 39 patients with primary CRC, 34 patients with adenomas, 17 patients with hyperplastic polyps and 20 endoscopically normal subjects as normal controls. Simultaneously we analyzed the correlation of hypermethylated SFRP1 and SFRP2 with the clinicopathological features of CRC. Results:Hypermethylated SFRP1 was detected in 92.3%, 76.5%, 47.1% of tissue samples and in 89.7%, 64.7%, 35.3% of matched fecal samples from CRC, adenoma and hyperplastic polyp, respectively. Hypermethylated SFRP2 was detected in 87.2%, 67.6%, 35.3% of tissue samples and in 82.1%, 55.9%, 29.4% of matched fecal samples from CRC, adenoma and hyperplastic polyp, respectively. Of these two genes, at least one hypermethylated was 94.9%, 82.4%, 52.9% in tissue samples and 92.3%,73.5%, 47.1% in matched fecal samples from CRC, adenoma and hyperplastic polyp, respectively. In contrast, no hypermethylated SFRP1 and SFRP2 were detected in mucosa tissues of normal controls, only 2 cases of fecal samples was detected with hypermethylated SFRP1 and another 1 case was detected with hypermethylated SFRP2. Moreover, no significant associations were observed between hypermethylated SFRP1,SFRP2 and clinicopathological features of CRC. Conclusion: Hypermethylation of SFRP1 and SFRP2 in feces are novel epigenetic biomarkers of CRC and carded high potential for the remote detection of CRC as non-invasive screening method, and combined analysis of hypermethylated SFRP1 and SFRP2 in fecal could further increase the detection rate of CRC and premalignant lesions.
基金Supported by Grants from the National Basic Research Program(973 Program), No. 2012CB934002, 2010CB912802National Key Scientific Instrument Special Programme of China, No.2011YQ03013405National Science Foundation of China,No. 81121004, 81071953 and 81161120432
文摘AIM: To explore epigenetic changes in the gene encod- ing X chromosome-linked inhibitor of apoptosis-associ- ated factor 1 (XAF1) during esophageal carcinogenesis. METHODS: Methylation status of XAF1 was detected by methylation-specific polymerase chain reaction (MSP) in four esophageal cancer cell lines (KYSE30, KYSE70, BICl and partially methylated in TE3 cell lines), nine cases of normal mucosa, 72 cases of pri- mary esophageal cancer and matched adjacent tissue. XAF1 expression was examined by semi-quantitative reverse transcriptional polymerase chain reaction and Western blotting before and after treatment with 5-aza- deoxycytidine (5-aza-dc), a demethylating agent. To investigate the correlation of XAF1 expression and methylation status in primary esophageal cancer, immu- nohistochemistry for XAF1 expression was performed in 32 cases of esophageal cancer and matched adjacent tissue. The association of methylation status and clini-copathological data was analyzed by logistic regression. RESULTS: MSP results were as follows: loss of XAF1 expression was found in three of four esophageal cell lines with promoter region hypermethylation (com- pletely methylated in KYSE30, KYSE70 and BIC1 cell lines and partially in TE3 cells); all nine cases of normal esophageal mucosa were unmethylated; and 54/72 (75.00%) samples from patients with esophageal can- cer were methylated, and 25/72 (34.70%) matched adjacent tissues were methylated (75.00% vs 34,70%, z2 = 23.5840, P = 0.000). mRNA level of XAF1 mea- sured with semi-quantitative reverse transcription poly- merase chain reaction was detectable only in TE3 cells, and no expression was detected in KYSE30, KYSE70 or BIC1 cells. Protein expression was not observed in KYSE30 cells by Western blotting before treatment with 5-aza-dc. After treatment, mRNA level of XAF1 was detectable in KYSE30, KYSE70 and BIC1 cells. Protein expression was detected in KYSE30 after treatment with 5-aza-dc. Immunohistochemistry was performed on 32 cases of esophageal cancer and adjacent tissue, and demonstrated XAF1 in the nucleus and cytoplasm. XAF1 staining was found in 20/32 samples of adjacent normal tissue but was present in only 8/32 samples of esophageal cancer tissue (Z2= 9.143, P = 0.002). XAF1 expression was decreased in cancer samples compared with adjacent tissues. In 32 cases of esophageal can- cer, 24/32 samples were methylated, and 8/32 esopha- geal cancer tissues were unmethylated. XAF1 staining was found in 6/8 samples of unmethylated esophageal cancer and 2/24 samples of methylated esophageal cancer tissue. XAF1 staining was inversely correlated with XAF1 promoter region methylation (Fisher's exact test, P = 0.004). Regarding methylation status and clinicopathological data, no significant differences were found in sex, age, tumor size, tumor stage, or metas- tasis with respect to methylation of XAF1 for the 72 tis- sue samples from patients with esophageal cancer. CONCLUSION: XAF1 is frequently methylated in eso- phageal cancer, and XAF1 expression is regulated by promoter region hypermethylation.
基金Funded by the National Nature Science Foundation of China(No.51273156)the Open Foundation of Hubei key laboratory of Purification and Application of Plant Anti-cancer Active Ingredients(No.HLPAI2014005)
文摘Novel insulin-loaded nanoparticles based on hydroxypropyl-β-cyclodextrin modified carboxymethyl chitosan(CMC-HP-β-CD) were prepared to improve the oral bioavailability of insulin. The CMC-HP-β-CD was characterized by FT-IR spectroscopy and 1H-NMR spectra. The insulin-loaded nanoparticles were prepared through crosslinking with calcium ions, and the morphology and size of the prepared nanoparticles were characterized by transmission electron microscopy(TEM) and dynamic light scattering(DLS). Cumulative release in vitro study was performed respectively in simulated gastric medium fluid(SGF, p H=1.2), simulated intestinal fluid(SIF, p H=6.8) and simulated colonic fluid(SCF, p H=7.4). The encapsulation efficiency of insulin was up to 87.14 ± 4.32% through high-performance liquid chromatography(HPLC). Statistics indicated that only 15% of the encapsulated insulin was released from the CMC-HP-β-CD nanoparticles in 36 h in SGF, and about 50% of the insulin could be released from the nanoparticles in SIF, whereas more than 80% was released in SCF. In addition, the solution containing insulin nanoparticles could effectively reduce the blood glucose level of diabetic mice. The cytotoxicity test showed that the samples had no cytotoxicity. CMC-HP-β-CD nanoparticles are promising candidates as potential carriers in oral insulin delivery systems.
文摘A cationic cyclodextrin derivative 6-O-(hydroxypropyltrimethylammonia)-β-cyclodextrin (GTA-β-CD) with low degree of substitution was prepared through a convenient method in solid phase. The product could be used as a valuable chiral selector in the capillary electrophoresis (CE) separation of some acidic drug enantiomers such as naproxen, ofloxacin, ibuprofen and warfarin.