肝癌中cyclinD1扩增与HBV感染及病理学的关系

目的探讨癌基因ｃｙｃｌｉｎＤ１在肝癌发生发展中的作用以及与ＨＢＶ感染和临床病理之间的关系．方法取手术切除的肝细胞癌标本,用Ｓｏｕｔｈｅｒｎ杂交的方法对ｃｙｃｌｉｎＤ１和ＣＤＫ４癌基因以及ＨＢＶ的感染状态进行了检测,切片同时行病理检查．结果肝癌３９例中９例ｃｙｃｌｉｎＤ１存在２～３０倍的扩增（２３７％）,其中１例检出重组杂交带;３７例中５例（１３５％）有ＣＤＫ４的扩增;ＨＢＶＤＮＡ在肝癌组织中检出的阳性率为９４７％,ＨＢＶＤＮＡ整合率为７４４％．相关分析发现,ｃｙｃｌｉｎＤ１的扩增与ＣＤＫ４扩增,ＨＢＶＤＮＡ整合,肿瘤的分化高低和肿块大小等之间有相关关系,相关系数ｒ分别为０５１,０３１,０３９和０５５,全部Ｐ＜００５．结论ｃｙｃｌｉｎＤ１的扩增与ＨＢＶＤＮＡ的整合密切相关,并在肝癌的恶化进展中起着重要作用．     

Real-time imaging of histone H4 hyperacetylation in living cells

To visualize histone acetylation in living cells, we developed a genetically encoded fluorescent resonance energy transfer (FRET)-based indicator. Response of the indicator reflects changes in the acetylation state of both K5 and K8 in histone H4. Using this acetylation indicator, we were able to monitor the dynamic fluctuation of histone H4 acetylation levels during mitosis, as well as acetylation changes in response to structurally distinct histone deacetylase inhibitors.     

Effects of sodium arsenite on Cyclin D1 and Cyclin dependent kinase 4 of human normal liver cells

正Objective To investigate the effects of sodium arsenite(NaAsO_2)on the expressions of Cyclin D1 and Cyclin dependent kinase 4(CDK4)in human normal liver cells(L-02).Methods L-02 cells were exposed to differ-ent doses of NaAsO_2(0,50,100,150μmol/L)for 24 h,flow cytometry was used to detect the cell cycle,real time quantitative PCR and Western blotting were used to detect the Cyclin D1,CDK4 mRNA and protein expres-     

Induction of unscheduled DNA synthesis in human myeloma cells

Unscheduled DNA synthesis (UDS) induced by melphalan, nitrogen mustard and ultra-violet irradiation was studied in bone marrow cells from myeloma patients. In a previous study, normal bone marrow cells in various stages of maturation were found to display a gradual decrease in UDS parallel with the process of maturation. Myeloma cells showed a similar pattern. Poorly differentiated myeloma cells exhibited a similar level of UDS to myeloblasts and erythroblasts. Irrespective of which repair-inducing agent was used, the relationship between the levels of UDS in the various cell types was constant. This indicates that the differences in the level of UDS in the various cell types was not due to differences in the uptake of the repair-inducing agent.     

Cyclin D1 activation in B-cell malignancy: association with changes in histone acetylation, DNA methylation, and RNA polymerase II binding to both promoter and distal sequences

Cyclin D1 expression is deregulated by chromosome translocation in mantle cell lymphoma and a subset of multiple myeloma. The molecular mechanisms involved in long-distance gene deregulation remain obscure, although changes in acetylated histones and methylated CpG dinucleotides may be important. The patterns of DNA methylation and histone acetylation were determined at the cyclin D1 locus on chromosome 11q13 in B-cell malignancies. The cyclin D1 promoter was hypomethylated and hyperacetylated in expressing cell lines and patient samples, and methylated and hypoacetylated in nonexpressing cell lines. Domains of hyperacetylated histones and hypomethylated DNA extended over 120 kb upstream of the cyclin D1 gene. Interestingly, hypomethylated DNA and hyperacetylated histones were also located at the cyclin D1 promoter but not the upstream major translocation cluster region in cyclin D1-nonexpressing, nontumorigenic B and T cells. RNA polymerase II binding was demonstrated both at the cyclin D1 promoter and 3' immunoglobulin heavy-chain regulatory regions only in malignant B-cell lines with deregulated cyclin D1 expression. Our results suggest a model where RNA polymerase II bound at IgH regulatory sequences can activate the cyclin D1 promoter by either long-range polymerase transfer or tracking.     

Long interspersed nuclear element-1 hypomethylation is associated with poor outcomes via the activation of ST18 in human hepatocellular carcinoma

The level of long interspersed nuclear element-1 (LINE-1) methylation, representing the global deoxyribonucleic acid methylation level, could contribute to the prognosis of cancer via the activation of oncogenes. This study was performed to evaluate the prognostic implications of LINE-1 hypomethylation in patients with hepatocellular carcinoma (HCC) and the possible mechanisms related to oncogene activation.Seventy-seven HCC patients between October 2014 and September 2015 were enrolled in this prospective study. Quantitative pyrosequencing was performed to assess the LINE-1 methylation level of HCC and matched non-HCC tissue samples. The expression of suppression of tumorigenicity 18 was measured by immunohistochemistry and its correlation with LINE-1 methylation levels was examined.LINE-1 was significantly hypomethylated in the HCC tissue compared with the matched nontumor tissue (64.0 ± 11.6% vs 75.6 ± 4.0%, P < .001). LINE-1 hypomethylation was an independent risk factor for overall survival (hazard ratio = 27.291, P = .032) and disease progression (hazard ratio = 5.298, P = .005). The expression of suppression of tumorigenicity 18 was higher in the hypomethylated LINE-1 HCC tissue than the hypermethylated LINE-1 tumor tissue (P = .030).LINE-1 hypomethylation may serve as a potential prognostic marker for patients with HCC.     

Cyclin D1 protein expression predicts metastatic behavior in thyroid papillary microcarcinomas but is not associated with gene amplification

Overexpression of cyclin D1 occurs in several malignancies, often due to gene amplification, and this has been associated with aggressive tumor behavior, a higher incidence of lymph node metastases, and a poorer prognosis. The role of cyclin D1 in the pathogenesis of thyroid malignancy is unknown; however, cyclin D1 expression has been reported to occur in a proportion of well differentiated thyroid carcinomas. Micropapillary carcinomas of the thyroid are common incidental findings that almost always behave in an indolent manner and remain quiescent. However, rare microcarcinomas behave aggressively and metastasize early, giving rise to clinically significant disease. We hypothesized that cyclin D1 might play a role in the aggressive behavior of metastasizing papillary microcarcinomas. We reviewed the histopathology reports of 2,000 patients who underwent thyroid surgery at our institution between 1995-1999 and identified 22 patients who presented with gross regional metastases from a primary papillary microcarcinoma. These patients formed the index cohort for this analysis. As controls, we selected 34 patients with nonmetastasizing microcarcinomas. We studied these tumors for immunoreactivity to cyclin D1 on immunohistochemistry and analyzed 13 tumors that diffusely expressed cyclin D1 for gene amplification by differential PCR. Twenty of the 22 (90.9%) metastasizing papillary microcarcinomas expressed cyclin D1, compared with 3 of the 34 (8.8%) nonmetastasizing papillary microcarcinomas (P < 0.001). However, of the 13 tumors that showed diffuse immunoreactivity for cyclin D1 on immunohistochemistry, none showed amplification of the cyclin D1 gene on differential PCR. We conclude that cyclin D1 is significantly overexpressed in metastasizing papillary microcarcinomas of the thyroid. This is likely due to mechanisms other than gene amplification. Cyclin D1 immunohistochemistry may be a valuable tool in predicting metastatic potential in papillary microcarcinomas.     

Cyclin D1在乳腺肿瘤组织中的表达及其与基因扩增的相关性

目的研究细胞周期蛋白（Cyclin D1）表达在乳腺肿瘤发生中的作用及影响因素。方法采用免疫组化染色法检测122例乳腺恶性肿瘤和良性乳腺增生标本Cyclin D1表达;Southern杂交方法检测Cyclin D1基因变异。结果40例良性乳腺增生组织均未观察到Cyclin D1表达,40例浸润性导管癌组织、早期乳腺癌和淋巴结转移病变组织阳性率分别为55．0％（22／40）、52．0％（22／42）和53．3％（8／15）;25例浸润性导管癌组织Cyclin D1基因扩增率为16．0％,明显低于其蛋白表达率。结论Cyclin D1表达在乳腺癌发病早期即发挥作用,其在肿瘤发生、发展过程中的作用尚受基因扩增以外因素的影响。     

Interleukin-1 accelerates autocrine growth of myeloma cells through interleukin-6 in human myeloma

Recombinant interleukin 1 alpha (rIL-1 alpha) augmented proliferation of freshly isolated myeloma cells as well as B-cell stimulatory factor 2 (BSF-2)/interleukin-6 (IL-6). Recombinant IL-1 alpha-induced proliferation was partially inhibited by anti-IL-6 antibody. In the culture supernatants of rIL-1 alpha-stimulated myeloma cells, IL-6 activities, which were measured by using an IL-6-dependent murine hybridoma clone, MH60.BSF2, were increased, when compared with those in the culture supernatants of nonstimulated myeloma cells. Furthermore, IL-6 messenger RNA (mRNA) expression was also augmented in IL-1 alpha- stimulated myeloma cells. Therefore rIL-1 alpha stimulates myeloma cells to produce IL-6, which consequently augments proliferation of myeloma cells. Thus, IL-1 can accelerate autocrine growth of myeloma cells through IL-6.     

Wortmannin对胃癌SGC7901细胞增殖及Cyclin H和Cyclin D1蛋白表达的影响

目的观察Wortmannin对胃癌SGC7901细胞增殖及细胞周期调控蛋白Cyclin H和Cyclin D1表达的影响，探讨Wortmannin抑制细胞增殖的机制。方法采用MTT法观察Wortmannin对胃癌细胞SGC7901增殖的影响，采用免疫细胞化学方法检测Cyclin H和Cyclin D1的表达。结果以不同浓度Wortmannin处理人中分化胃腺癌SGC7901细胞系48h后，该细胞的增殖受抑，呈剂量依赖性，随药物浓度的增大，OD值明显减少，同时增殖抑制率明显升高，且与对照组相比存在显著性差异（P〈0．05）；Wortmannin在下调Cyclin H同时亦可下调Cydin D1表达。结论Wortmannin有明显的抑制人中分化胃腺癌SGC7901细胞系增殖的作用，其分子机制可能是Wortmannin通过下调Cyclin H和Cyclin D1的表达，来抑制胃癌SGC7901细胞增殖，达到抗肿瘤的作用，因此该药有望成为胃癌化疗的一种新药。