Kaiso通过抑制cyclin D1转录影响肺癌细胞增殖和周期

目的研究Kaiso对cyclin D1转录抑制作用,探讨Kaiso抑制肺癌细胞增殖的分子机制。方法MTT和流式细胞仪检测A549和H1299两种肺腺癌细胞增殖和周期改变;Western blot和RT-PCR检测cyclin D1表达改变;生物信息学方法预测并设计cyclin D1启动子区Kaiso结合位点(KBS)的引物探针,ChIP证实Kaiso与cyclinD1启动子区结合。结果 Kaiso能够直接结合cyclin D1启动子区KBS,抑制cyclinD1转录,导致细胞增殖下降,G/G期比例升高,S期比例下降。结论 Kaiso通过下调cyclin D1转录抑制肿瘤细胞增殖和周期进程。     

Frequent cyclin D1 expression in chromate-induced lung cancers

Ex-chromate workers are frequently afflicted with lung cancers, especially central-type squamous cell carcinomas (SCCs) of the lung. However, little is known about the molecular and cellular biologic characteristics of chromate-induced lung cancers. We investigated expression of cyclin D1, bcl-2, and p53 proteins in chromate-induced lung cancers by immunohistochemistry, compared with those in lung cancers from nonexposed individuals and those in individuals with pneumoconiosis. Of 19 chromate-induced lung cancers, 16 tumors were SCCs, including 11 central and 5 peripheral types. Eleven (69%) of 16 chromate SCCs showed cyclin D1 expression. In contrast, cyclin D1 expression was observed in only 3 (12%) of 26 SCCs from nonexposed individuals and 6 (16%) of 37 SCCs that developed in patients with pneumoconiosis, respectively. The frequency of cyclin D1 expression proved to be significantly higher in chromate-induced SCCs than in SCCs from nonexposed individuals and from those with pneumoconiosis (P < .001). When comparisons were extended to all histologic types of lung cancer, cyclin D1 expression was observed significantly more often in chromate-induced lung cancers than in lung cancers from nonexposed subjects and those from patients with pneumoconiosis (11 [58%] of 19 v 5 [10%] of 52, P < .001, and 7 [11%] of 63, P < .001, respectively). Frequencies of bcl-2 and p53 expression were not significantly different among lung cancers from ex-chromate workers, nonexposed individuals and those with pneumoconiosis. The current study suggests that cyclin D1 expression may be involved in the development of chromate-induced lung cancers, although its underlying mechanism remains to be determined.     

微小RNA-146a 上调cyclin D1 表达诱导大鼠血管平滑肌细胞的增殖

目的:采用基因芯片技术研究小分子RNA-146a(miR-146a)促进血管平滑肌细胞增殖的作用靶点并进行验证。方法:原代培养大鼠血管平滑肌细胞,分成mimics 组、inhibitor 组、control 组、sham 组,分别体外转染miR-146a mimics(50nmol/ L)、miR-146a inhibitor(50 nmol/ L)、miR-146a 错义链(50 nmol/ L)、PBS,Real time PCR 测定转染后miR-146a 水平,CCK8法检测转染后血管平滑肌细胞增殖情况。采用基因芯片检测inhibitor 组和control 组基因表达谱,通过生物信息学技术筛选出差异基因和调控的信号通路。对筛选出来的信号通路用Real time PCR 和Western blot 进行验证。结果:转染48 h后,inhibitor 组血管平滑肌细胞的miR-146a 水平明显低于control 组和sham 组(P<0.01),inhibitor 组血管平滑肌细胞的OD 值明显低于control 组、sham 组(P<0.05)。通过对基因表达谱分析发现,p53 信号通路被miR-146a 上调。用Real time PCR 和Western blot进行检测发现,p53 信号通路中关键分子p53、caspase3、PTEN 的mRNA 和蛋白水平无明显变化(P>0.05),而mimics 组VSMC中cyclin D1 的mRNA 和蛋白水平增加(与sham 相比,P<0.05),inhibitor 组VSMC 中cyclin D1 的mRNA 和蛋白水平下降(与sham相比,P<0.05)。结论: miR-146a 可能通过上调细胞周期蛋白cyclin D1 的表达促进大鼠血管平滑肌细胞的增殖。     

Expression of beta-catenin in hepatocellular carcinoma in relation to tumor cell proliferation and cyclin D1 expression

Alteration of beta-catenin expression has been implicated in the development of hepatocellular carcinoma (HCC). It has been also reported that beta-catenin can influence the tumor cell proliferation or cyclin D1 expression, one of the target factors of betacatenin. We performed an immunohistochemical analysis of beta-catenin and cyclin D1 in 77 patients with resected HCCs, and examined the relationships between the expressions of beta-catenin and cyclin D1, and other pathologic parameters including the mitotic index. Altered expressions of beta-catenin including nonnuclear overexpression and nuclear expression were detected in 58.4% of HCCs (45/77) and showed significant correlations with large tumor size, poor histologic grade, and high tumor stage. The mean mitotic index of HCCs with nuclear expression (3.2 +/- 3.0) and nonnuclear overexpression (2.7 +/- 2.5) was significantly higher than that of tumors with no overexpression (1.7 +/- 1.4) (p=0.018 and 0.038, respectively), however, no correlation was noted between the expressions of cyclin D1 and beta-catenin. In addition, nonnuclear overexpression out of two altered expression patterns was more frequent (37.7% versus 20.8%) as well as pathologically more significant than nuclear expression. These results indicate that the altered expression of beta-catenin in HCC may play an important role in tumor progression by stimulating tumor cell proliferation, and nonnuclear overexpression may have pathologic significance in HCC.     

沉默NANOG表达对人肝癌细胞HepG2中cyclin D1表达及细胞增殖的影响

 目的:探讨RNA干扰沉默NANOG表达后对肝癌细胞HepG2中细胞周期素D1(cyclin D1)表达及细胞增殖的影响。方法:将以NANOG基因为靶点的NANOG-siRNA瞬时转染肝癌细胞HepG2,real-time PCR和Western boltting检测NANOG、cyclin D1 mRNA和蛋白的表达,CCK-8和平板克隆形成实验检测细胞增殖能力,流式细胞术检测细胞周期情况。结果:与mock组比较,转染NANOG-siRNA后,肝癌细胞HepG2中NANOG、cyclin D1 mRNA和蛋白水平均下调(P＜0.05),细胞增殖能力下降(P＜0.05),进入G 0/G 1期的细胞比例增多(P＜0.05)。结论:沉默NANOG表达可引起肝癌细胞HepG2中cyclin D1的表达下降,导致细胞增殖能力下降。     

Evaluation of cyclin D1 expression and its subcellular distribution in mouse tissues

Cyclin D1 is a key cell-cycle regulatory protein required for the cell to progress through G1 to S phase. We have shown by Western blot analysis that cyclin D1 has a wide distribution in adult mouse tissues, with its level of expression being tissue-dependent. Immunohistochemistry has also shown that cyclin D1 may be present in the cytoplasm, in the nucleus or in both these cell compartments: cytoplasmic staining was observed in both proliferating cells (e.g. kidney, intestine, stomach and salivary gland) and in the non-dividing cells (the mature neurons of adult brain), while nuclear staining was seen in the neurons of the embryonic nervous system. Immunoelectron microscopy results indicate that, in tissues where cyclin D1 is present in both compartments (e.g. intestinal enterocytes), it may move via nuclear pores from the nucleus to the cytoplasm, and vice versa. The findings as a whole suggest that cyclin D1 may play multiple roles within specific tissues, probably by interacting with different substrates, and that its transit between nuclear and cytoplasmic compartments may help maintain cell homeostasis.     

Functional consequences of cyclin D1 overexpression in human mammary luminal epithelial cells

The proliferation of eukaryotic cells is primarily regulated by a decision made during the G1 phase of the cell cycle as to remain in the cycle and divide, or to withdraw from the cycle and adopt a different cell fate. During this time, environmental signals, which regulate the synthesis of the G1 cyclins, are coupled to cell division. In this context, mammalian D-type cyclins have been shown to control progression through the G1 phase of the mammalian cell cycle. Specifically, cyclin D1 has been reported frequently to be amplified, over-transcribed and overexpressed in human breast carcinomas. Although the effects of cyclin D1 overexpression have been examined in human breast carcinoma cell lines, the biological consequences of cyclin D1 expression in normal human mammary epithelial cells remain to be elucidated. In this study we have stably over expressed cyclin D1 in human mammary luminal epithelial cells in order to more directly address the role of cyclin D1 in cell cycle control and tumorigenesis of the human breast. Here, we demonstrate that the effect of cyclin D1 overexpression in these cells is to reduce their growth factor dependency, as well as shorten the duration of G1 and correspondingly reduce the mean generation time. Collectively, our data indicate that deregulation of cyclin D1 expression in human mammary epithelial cells can provide a growth advantage and hence contribute to the oncogenic potential of these cells.     

Functional consequences of cyclin D1 overexpression in human mammary luminal epithelial cells

The proliferation of eukaryotic cells is primarily regulated by a decision made during the G1 phase of the cell cycle as to remain in the cycle and divide, or to withdraw from the cycle and adopt a different cell fate. During this time, environmental signals, which regulate the synthesis of the G1 cyclins, are coupled to cell division. In this context, mammalian D-type cyclins have been shown to control progression through the G1 phase of the mammalian cell cycle. Specifically, cyclin D1 has been reported frequently to be amplified, over-tran-scribed and overexpressed in human breast carcinomas. Although the effects of cyclin D1 overexpression have been examined in human breast carcinoma cell lines, the biological consequences of cyclin D1 expression in normal human mammary epithelial cells remain to be elucidated. In this study we have stably over expressed cyclin D1 in human mammary luminal epithelial cells in order to more directly address the role of cyclin D1 in cell cycle control and tumorigenesis of the human breast. Here, we demonstrate that the effect of cyclin D1 overexpression in these cells is to reduce their growth factor dependency, as well as shorten the duration of G1 and correspondingly reduce the mean generation time. Collectively, our data indicate that deregula-tion of cyclin D1 expression in human mammary epithelial cells can provide a growth advantage and hence contribute to the oncogenic potential of these cells. © Rapid Science Ltd.     

Regulation of 1-cys peroxiredoxin expression in lung epithelial cells

1-cys peroxiredoxin (1-cys Prx), the only member of a Prx subfamily that contains a single conserved cysteine residue, is abundant in lung. This bifunctional protein has both glutathione peroxidase and phospholipase A2 activities compatible with a role both in protection against lung oxidant injury and also in lung phospholipid metabolism. Here we studied the developmental expression of 1-cys Prx in rat lungs and hormonal effects on protein expression in human and rat lung cells. There was little change in 1-cys Prx expression during the prenatal period, but a marked increase in expression immediately after birth. Enzymatic (peroxidase and phospholipase) activities increased gradually after birth and reached adult level at 7-14 postnatal days. Expression of the protein was induced in the presence of dexamethasone (Dex) in cultured human and rat lung epithelial cells and also was upregulated in neonatal rat lung in vivo. cAMP treatment had no effect on expression, although there was a modest synergistic effect when combined with Dex in human fetal lung epithelial cells. The increased expression of 1-cys Prx at birth may be important for surfactant phospholipid turnover related to the phopholipase A2 activity of the protein and for antioxidant defense based on its peroxidase function.     

异丹叶大黄素下调膀胱癌细胞的细胞周期蛋白D1表达并诱导G0/G1细胞周期阻滞

 目的：探索异丹叶大黄素（ISO）抑制膀胱癌细胞侵袭、转移和增殖活性的机制。方法：以ISO作用于人源性膀胱癌UMUC3细胞后,倒置相差显微镜下观察并以ATP生物荧光法检测癌细胞增殖活性;以RT-PCR和Western blotting法检测细胞周期蛋白D1表达;以流式细胞术检测细胞周期的变化;细胞划痕法检测细胞迁移活性。结果：20 μmol/L浓度以上ISO可显著抑制UMUC3细胞的增殖,其IC50为(22.5±2.8) μmol/L。同时 UMUC3细胞的细胞周期蛋白D1 mRNA和蛋白水平均显著降低。以低浓度5 μmol/L ISO预处理UMUC3细胞后,与对照组（47.33%）进行比较,可分别在12 h（58.82％）和24 h（63.94％）显著诱导细胞G0/G1期阻滞（P<0.01）。细胞划痕法检测证实5 μmol/L ISO可显著抑制膀胱癌细胞的迁移活性。结论：ISO可抑制膀胱癌细胞增殖,下调细胞周期蛋白D1表达,诱导G0/G1细胞周期阻滞,抑制细胞的迁移能力。     

Long lasting chronic hepatitis is accompanied by cyclin D1 gene expression in the mouse.

The interferon-gamma (IFN-gamma) transgenic mouse expresses the IFN-gamma gene strongly in the liver and develops chronic hepatitis from 6-10 weeks of age. Previously we reported the detection of hepatocyte apoptosis and the expression of the Fas system in the transgenic mouse liver. The objective of the present study was to examine the possible development of favorable conditions for predisposing cells to malignancy. The connection between the cell cycle and cancer has become evident, and the relation of cyclin D1 (CD1) with hepatocellular carcinomas has been strengthened. In the liver of transgenic mice of 48 weeks of age, c-myc and CD1 gene expression was induced, indicating progression of the cell cycles. p21 gene expression in the transgenic mouse liver might counteract cell-cycle progression promoted by c-myc and CD1. In the liver of 8-week-old transgenic mice, expression of c-myc mRNA was correlated with the levels of plasma transaminase activities. In these 8-week-old transgenic mice, however, CD1 mRNA was not induced, regardless of the progression of hepatitis. Based on these results, we conclude that long lasting hepatitis may lead to favorable conditions for predisposing cells to malignancy.     

肾癌中cyclinD1和p27kip1的表达及其意义

目的探讨cyc lin D1、p27k ip1在普通型肾细胞癌(renal cell carc inom a,RCC)发生、发展中的作用。方法用半定量RT-PCR方法检测25例普通型RCC和10例肿瘤远端的正常肾组织中cyc lin D1的mRNA含量,用免疫组化方法检测76例普通型RCC中cyc lin D1和p27k ip1蛋白的表达,并对cyc lin D1、p27k ip1蛋白表达与临床病理参数的关系进行分析。结果普通型RCC中cyc lin D1的mRNA含量0.488±0.399,高于正常对照组0.089±0.066(P<0.01)。cyc lin D1的表达与肿瘤体积大小有关,体积大者cyc lin D1高表达(P<0.05)。普通型RCC中p27k ip1表达低于正常对照组,随着p27k ip1表达的降低,肿瘤的细胞核Fu-hrm an分级、TNM分期增高。结论cyc lin D1高表达和p27k ip1的低表达与普通型RCC的发生有关;p27k ip1的低表达可能促进肿瘤的演进,p27k ip1的表达可作为评价普通型RCC预后的参考指标。     

Down-regulation of microRNA-27b promotes retinal pigment epithelial cell proliferation and migration by targeting Nox2

Aberrant proliferation and migration of retinal pigment epithelium (RPE) cells contributes to the pathology of various ocular diseases. miR-27b has been reported to be crucial in the regulation of cell differentiation, proliferation, apoptosis, and migration. However, the role of miR-27b on RPE proliferation and migration remains largely unknown. Here the effect of miR-27b on ARPE-19 cells under platelet-derived growth factor (PDGF)-BB stimulation was explored. In this study, we found that the expression level of miR-27b was significantly reduced in ARPE-19 cells under PDGF-BB stimulation. Ectopic expression of miR-27b remarkably inhibited PDGF-BB-induced proliferation and migration in ARPE-19 cells. Furthermore, bioinformatic analysis and luciferase reporter assay showed that NADPH oxidase 2 (Nox2) was a direct target for miR-27b, and that knockdown of Nox2 expression mimicked the inhibitory effect of miR-27b on PDGF-BB ?induced proliferation and migration in ARPE-19 cells, whereas, restoration of Nox2 expression showed an opposite effect. In addition, the ROS production and the activation of P13K/AKT/mTOR signaling induced by PDGF-BB were also suppressed by miR-27b overexpression or Nox2 silencing. Thus, these findings indicated that miR-27b exerted its protective role in RPE cells under PDGF-BB stimulation was partially through regulation of Nox2 and its downstream P13K/AKT/mTOR signaling, which might be a potential therapeutic approach for treatment of diseases caused by RPE proliferation, and migration.     

Cyclin D1 expression by histiocytes may mimic cyclin D1-positive proliferation centres of chronic lymphocytic leukaemia/small lymphocytic lymphoma

Aims

Cyclin D1, generally considered to be absent in chronic lymphocytic leukaemia/small lymphocytic lymphoma (CLL/SLL), has been reported in the proliferation centres (PCs) of recent CLL/SLL cases. Cyclin D1 immunostaining in CLL/SLL may lead to diagnostic confusion. The objective of this study was to identify the types of stained cells and the impact on diagnosis.