HLA-I表达与维吾尔族妇女宫颈癌前病变及HPV16感染的关系研究

目的：观察人白细胞相关抗原I（human leukocyte antigen class I,HLA-I）表达与维吾尔族妇女宫颈癌前病变进程及高危型HPV16的关系。方法：收集维吾尔族妇女宫颈炎、宫颈内上皮瘤样病变（cervical intraepithelial neoplasia,CIN）和宫颈鳞癌患者的石蜡包埋组织标本共148例,提取组织DNA,应用PCR的方法检测HPV阳性及HPV16型别;同时采用免疫组织化学SP法检测HLA-I蛋白表达水平。结果：（1）在维吾尔族妇女中HLA-I抗原在宫颈炎、CINI-II、CINIII、SCC组中阳性表达逐渐减少,差异有统计学意义（P〈0.001）。（2）HLA-I的阳性表达下降趋势与宫颈癌临床分期、组织分化程度和淋巴结转移密切相关。（3）HPV在宫颈炎、CINI-II、CINIII、宫颈癌中的感染率分别为13%、46%、82%、95%,差异有统计学（P〈0.001）。（4）HPV16在宫颈炎、CINI-II、CINIII、宫颈癌中的感染率分别为4%、30%、68%、85%,差异有统计学（P〈0.001）。（5）在HPV16阳性标本中,存在HLA-I表达缺失的占71%（58/82）,HPV16感染与HLA-I表达呈负相关（r=-0.625,P〈0.001）。结论：（1）HLA-I表达缺陷可能是宫颈病变进展的重要标志,对宫颈癌的预测预警提供依据。（2）HPV16感染在宫颈病变的发展过程中起到了极大的促进作用,是一个很强的致癌因素。（3）HPV16感染与HLA-I表达之间的关系对揭示宫颈癌发病机制提供了客观依据。     

抗原受体基因重组的表观遗传学调控研究新进展

淋巴细胞是哺乳动物唯一能发生体细胞基因组变化的一类细胞,淋巴细胞在发育过程中通过V(D)J重组获得成熟的特异的抗原受体基因,实现了免疫细胞抗原识别惊人的多样性.关于V(D)J重组的调控机制一直是免疫学研究的重要问题,然而直到将表观遗传学研究引入这一领域,综合遗传学和表观遗传学的研究才真正揭示V(D)J重组精细的调控机制.综述了新近发现的V(D)J重组过程中重要的表观遗传学调控机制,如CpG甲基化,组蛋白修饰,核小体重塑及核拓扑学变化.     

肿瘤MDR1基因表观遗传调控及其对宫颈癌的启示

多药耐药是肿瘤细胞化疗失败的重要原因,多药耐药基因1过度表达P-gP是产生耐药的主要机制,表观遗传通过对DNA的甲基化和组蛋白脱乙酰化的修饰来调节MDR1基因的转录.应用化学物质可以逆转MDR1基因的过度表达,提高化疗敏感性,这将为癌症治疗提供新策略,也为宫颈癌的治疗提供新思路.     

Irisin and Carcinoembryonic Antigen (CEA) as Potential Diagnostic Biomarkers in Gastric and Colorectal Cancers

Background:Carcinoembryonic antigen (CEA) is a common gastrointestinal tumor biomarker. Irisin is adipo-myokines that has been suggested to have a potential role in cancer development. However, limited studies test irisin as biomarker in gastric and colorectal cancers. Therefore, this study aims to investigate whether CEA and irisin could be a potential diagnostic biomarker in gastric and colorectal cancer.Methods:A case-control study consists of 90 subjects, 21 gastric cancer patients, 49 colorectal cancer patients and 20 control. Serum CEA was detected by fluorescence immunoassay (FIA) kit. Serum irisin was determined by enzyme-linked immunosorbent assay (ELISA) kit.Results:Serum CEA increases significantly and serum irisin decreases significantly in gastric and colorectal cancer patients. According to Receiver Operating Characteristic (ROC) curve analysis, in gastric cancer, the area under curve of CEA is 1.00 (95% CI, 1.000-1.000, p< 0.0001). The diagnostic cut-off of CEA is< 3.08 ng/ml with %100 sensitivity and 100% specificity. The area under curve of irisin is 0.94 (95% CI, 0.8177-1.000, p< 0.0001). The cut-off of irisin is> 30.2 ng/ml with %90 sensitivity and 100%, specificity. In colorectal cancer, the area under curve of CEA is 0.99 (95% CI, 0.9866-1.000, p< 0.0001) and the diagnostic value< 2.6 ng/ml with %98 sensitivity and %100 specificity. The area under curve of irisin is 0.96 (95% CI, 0.9155-1.000, p< 0.0001). The diagnostic cut-off of irisin is> 41.9 ng/ml with 88.1sensitivity and 90.5 specificity.Conclusion:CEA and irisin could be powerful potential diagnostic biomarkers which would be use for early detection of gastric and colorectal cancers.Key Words: Biomarker, Carcinoembryonic antigen (CEA), Colorectal cancer, Gastric cancer, Irisin     

Epigenetic Mechanisms Regulate MHC and Antigen Processing Molecules in Human Embryonic and Induced Pluripotent Stem Cells

Background

Human embryonic stem cells (hESCs) are an attractive resource for new therapeutic approaches that involve tissue regeneration. hESCs have exhibited low immunogenicity due to low levels of Mayor Histocompatibility Complex (MHC) class-I and absence of MHC class-II expression. Nevertheless, the mechanisms regulating MHC expression in hESCs had not been explored.

Methodology/Principal Findings

We analyzed the expression levels of classical and non-classical MHC class-I, MHC class-II molecules, antigen-processing machinery (APM) components and NKG2D ligands (NKG2D-L) in hESCs, induced pluripotent stem cells (iPSCs) and NTera2 (NT2) teratocarcinoma cell line. Epigenetic mechanisms involved in the regulation of these genes were investigated by bisulfite sequencing and chromatin immunoprecipitation (ChIP) assays. We showed that low levels of MHC class-I molecules were associated with absent or reduced expression of the transporter associated with antigen processing 1 (TAP-1) and tapasin (TPN) components in hESCs and iPSCs, which are involved in the transport and load of peptides. Furthermore, lack of β2-microglobulin (β2m) light chain in these cells limited the expression of MHC class I trimeric molecule on the cell surface. NKG2D ligands (MICA, MICB) were observed in all pluripotent stem cells lines. Epigenetic analysis showed that H3K9me3 repressed the TPN gene in undifferentiated cells whilst HLA-B and β2m acquired the H3K4me3 modification during the differentiation to embryoid bodies (EBs). Absence of HLA-DR and HLA-G expression was regulated by DNA methylation.

Conclusions/Significance

Our data provide fundamental evidence for the epigenetic control of MHC in hESCs and iPSCs. Reduced MHC class I and class II expression in hESCs and iPSCs can limit their recognition by the immune response against these cells. The knowledge of these mechanisms will further allow the development of strategies to induce tolerance and improve stem cell allograft acceptance.     

表皮生长因子受体信号通路在维吾尔族妇女宫颈癌中的表达研究

目的:随着表皮生长因子受体(epidermal growth factor receptor,EGFR)靶点治疗药物在其它肿瘤治疗中的应用,能否在妇科肿瘤中应用并取得疗效,已经得到学者们的重视。但在临床应用之前,必须明确EGFR与妇科肿瘤发生发展的关系及其机制。因此,我们来探讨表皮生长因子受体EGFR信号通路在维吾尔族不同级别宫颈病变组织中的差异表达及其临床意义。方法:应用免疫组织化学方法检测EGFR、P-EGFR、ERK 1/2、P-ERK1/2在108例子宫颈癌,47例CIN,79例正常宫颈组织中的表达,并分析其与临床病理参数的关系。结果:EGFR在子宫颈癌、CIN及正常宫颈组织中的阳性表达率分别是74.10%、66%、27.80%(P0.01);P-EGFR在三组间的阳性表达率分别是55.60%、74.50%、20.30%(P0.01);ERK1/2在三组间的阳性表达率分别是60.10%、76.60%、25.30%(P0.01);P-ERK1/2在三组间的阳性表达率分别是44.40%、66%、24.10%(P0.01),其在宫颈癌中EGFR与与浸润深度、淋巴结转移有关;ERK与肿瘤的临床分期、远处转移有关,而且在宫颈癌中EGFR与P-EGFR、ERK 1/2、P-ERK1/2的表达成正相关(P0.05)。结论:EGFR、P-EGFR、ERK1/2、P-ERK1/2的表达与宫颈癌的发生、发展相关,促进宫颈癌的浸润和转移,抑制EGFR信号通路可能为多靶点联合治疗宫颈癌提供新的方向。     

Reduced Expression of the Antigen Processing Machinery Components TAP2, LMP2, and LMP7 in Tonsillar and Base of Tongue Cancer and Implications for Clinical Outcome

OBJECTIVES: Patients with human papillomavirus (HPV)–positive tonsillar squamous cell carcinoma (TSCC) and base of tongue squamous cell carcinoma (BOTSCC) have a better clinical outcome than those with corresponding HPV-negative tumors. Moreover, there is a strong positive correlation between absent/low as opposed to strong HLA class I expression and favorable clinical outcome for HPV-positive tumors, while the reverse applies to HPV-negative tumors. The expression of the antigen processing machinery (APM) components TAP1, TAP2, LMP2, and LMP7 in these tumors in relation to HPV status, HLA class I expression, each other, and clinical outcome was therefore investigated. MATERIAL AND METHODS: Formalin-fixed paraffin-embedded TSCC and BOTSCC, derived from 151 patients and previously analyzed for HPV DNA, HLA class I, and LMP10 expression were stained by immunohistochemistry for TAP1, TAP2, LMP2, and LMP7. RESULTS: Absent/low TAP2, LMP2, and LMP7 expression, similar to HLA class I and LMP10, was common in TSCC and BOTSCC, irrespective of HPV status. Expression of TAP1 and TAP2 was correlated, as was LMP2 to LMP7. LMP2 and LMP7 expression was also associated to HLA class I expression. Moreover, absence of LMP7 was linked to increased disease-free survival in both HPV-positive and HPV-negative cases. CONCLUSION: Reduced expression of TAP2, LMP2, and LMP7 was frequent in TSCC and BOTSCC and their expression as well as that of TAP1 was often interrelated. Furthermore, low LMP7 expression correlated to better clinical outcome and may, together with HPV status, potentially be used for prediction of treatment response.     

Epigenetic Regulation of a Brain-specific Glycosyltransferase N-Acetylglucosaminyltransferase-IX (GnT-IX) by Specific Chromatin Modifiers

Expression of glycosyltransferase genes is essential for glycosylation. However, the detailed mechanisms of how glycosyltransferase gene expression is regulated in a specific tissue or during disease progression are poorly understood. In particular, epigenetic studies of glycosyltransferase genes are limited, although epigenetic mechanisms, such as histone and DNA modifications, are central to establish tissue-specific gene expression. We previously found that epigenetic histone activation is essential for brain-specific expression of N-acetylglucosaminyltransferase-IX (GnT-IX, also designated GnT-Vb), but the mechanism of brain-specific chromatin activation around GnT-IX gene (Mgat5b) has not been clarified. To reveal the mechanisms regulating the chromatin surrounding GnT-IX, we have investigated the epigenetic factors that are specifically involved with the mouse GnT-IX locus by comparing their involvement with other glycosyltransferase loci. We first found that a histone deacetylase (HDAC) inhibitor enhanced the expression of GnT-IX but not of other glycosyltransferases tested. By overexpression and knockdown of a series of HDACs, we found that HDAC11 silenced GnT-IX. We also identified the O-GlcNAc transferase (OGT) and ten-eleven translocation-3 (TET3) complex as a specific chromatin activator of GnT-IX gene. Moreover, chromatin immunoprecipitation (ChIP) analysis in combination with OGT or TET3 knockdown showed that this OGT-TET3 complex facilitates the binding of a potent transactivator, NeuroD1, to the GnT-IX promoter, suggesting that epigenetic chromatin activation by the OGT-TET3 complex is a prerequisite for the efficient binding of NeuroD1. These results reveal a new epigenetic mechanism of brain-specific GnT-IX expression regulated by defined chromatin modifiers, providing new insights into the tissue-specific expression of glycosyltransferases.     

Rescue of MHC-1 Antigen Processing Machinery by Down-Regulation in Expression of IGF-1 in Human Glioblastoma Cells

Escape from immune recognition has been hypothesized to be a factor in carcinogenesis. It may be mediated for many cancers through down-regulation in the MHC class 1 antigen processing and presentation pathway. TAP-1, TAP-2, tightly linked to LMP-2 and LMP-7 are multiple components of the endogenous, antigen presentation pathway machinery. We addressed the question of alterations in this pathway in human Glioblastoma (HGB) and of its relationship to modulation in expression of IGF-1 that is highly expressed in this cancer. Deficiencies in expression of TAP-1 were demonstrated by RT-PCR and/or by immuno-flow cytometry in the HGB cell line T98G obtained from ATCC, and in 3 of 4 human cell lines established from patients with Glioblastoma Multiforme. Deficiencies in expression of TAP-2 were observed in 3 of 4, deficiencies in expression of LMP-2 in 4 of 4 and deficiencies in LMP-7 in 3 of 4 HGB cell lines examined by RT-PCR and Western blot. Following down-regulation of IGF-1 by transfection with the pAnti IGF-1 vector that expresses IGF-1 RNA in antisense orientation, or by the exogenous addition of IGF-1 receptor monoclonal antibody to cell culture media, the deficiencies in components of the MHC-1 antigen presentation pathway were up-regulated and/or rescued in all HGB cell lines tested. Moreover, this up-regulation in expression was aborted by addition of 100 ng/ml of IGF-1 to the culture media. Unlike in the case of IFN-γ, the restoration of TAP-1 and LMP-2 by down-regulation of IGF-1 in Glioblastoma cells was not correlated to the tyrosine phosphorylation of STAT 1. In summary, the simultaneous reversion in expression of the multiple constituents of MHC-1 antigen processing path and up-regulation in expression of MHC-1 occurring with down-regulation in IGF-1 may have a role in reinforcement of immunity against tumor antigen(s) in some animal cancers and in humans with Glioblastoma Multiforme.     

Epigenetic Regulation of Chondrocyte Catabolism and Anabolism in Osteoarthritis

Osteoarthritis (OA) is one of the most prevalent forms of joint disorder, associated with a tremendous socioeconomic burden worldwide. Various non-genetic and lifestyle-related factors such as aging and obesity have been recognized as major risk factors for OA, underscoring the potential role for epigenetic regulation in the pathogenesis of the disease. OA-associated epigenetic aberrations have been noted at the level of DNA methylation and histone modification in chondrocytes. These epigenetic regulations are implicated in driving an imbalance between the expression of catabolic and anabolic factors, leading eventually to osteoarthritic cartilage destruction. Cellular senescence and metabolic abnormalities driven by OA-associated risk factors appear to accompany epigenetic drifts in chondrocytes. Notably, molecular events associated with metabolic disorders influence epigenetic regulation in chondrocytes, supporting the notion that OA is a metabolic disease. Here, we review accumulating evidence supporting a role for epigenetics in the regulation of cartilage homeostasis and OA pathogenesis.     

553 例女性宫颈高危型HPV 感染与宫颈病变的相关性研究

目的:研究女性生殖道高危型人乳头瘤病毒(high risk human papilloma virus,hrHPV)感染现状及子宫颈上皮内瘤样病变(cervical intraepithelial neoplasia,CI N)的现患率,并分析该人群年龄与HPV感染及宫颈癌前病变的相关性以及hrHPV病毒载量与宫颈病变之间剂量-效应关系。方法:对553例30岁-78岁有性生活史的女性进行以人群为基础的横断面调查。对所有接受筛查的妇女均行宫颈HPV检测及电子阴道镜下病理活检,并以病理结果作为诊断子宫颈病变的金标准。资料采用EXCEL整理,利用x2检验和非条件Logistic回归分析危险因素和CI N的关系。结果:553例受检对象总体阳性检出率为18.0%。hrHPV感染情况在不同年龄段分布有显著差异,hrHPV病毒载量越高宫颈病变的程度越重。结论:不同年龄段hrHPV感染情况不同,hrHPV病毒载量与宫颈病变之间存在剂量-效应关系。     

553例女性宫颈高危型HPV感染与宫颈病变的相关性研究

目的：研究女性生殖道高危型人乳头瘤病毒（high risk human papilloma virus,hrHPV）感染现状及子宫颈上皮内瘤样病变（cervical intraepithelial neoplasia,CI N）的现患率,并分析该人群年龄与HPV感染及宫颈癌前病变的相关性以及hrHPV病毒载量与宫颈病变之间剂量-效应关系。方法：对553例30岁-78岁有性生活史的女性进行以人群为基础的横断面调查。对所有接受筛查的妇女均行宫颈HPV检测及电子阴道镜下病理活检,并以病理结果作为诊断子宫颈病变的金标准。资料采用EXCEL整理,利用x2检验和非条件Logistic回归分析危险因素和CI N的关系。结果：553例受检对象总体阳性检出率为18.0%。hrHPV感染情况在不同年龄段分布有显著差异,hrHPV病毒载量越高宫颈病变的程度越重。结论：不同年龄段hrHPV感染情况不同,hrHPV病毒载量与宫颈病变之间存在剂量-效应关系。     

Chemical Components from Craniotome furcata (in English)

Four compounds, craniosides A (1) and B (2), mussaenoside (3) and ningpogenin (4) were isolated from the ethyl acetate fraction of Craniotome furcata (Link.) O. Kuntze for the first time. Among them, craniosides A (1) and B (2) were identified as new compounds. The structures of the two new compounds were assigned mainly by spectral methods.     

表观遗传调控在糖尿病及其并发症中的作用

表观遗传(epigenetics)是指DNA序列不发生变化但基因表达却发生了可遗传的改变．表观遗传调控过程十分复杂,主要包括DNA甲基化、组蛋白修饰和微小RNA(miRNA)等．糖尿病是一种慢性代谢性疾病,常伴随大血管和微血管并发症．糖尿病的发生、发展不仅取决于遗传因素,而且也受到表观遗传修饰的调控．因此,对表观遗传调控的研究将为糖尿病及其并发症的预防和治疗提供新的思路和方法．