Prognostic significance of p27Kip1 expression in colorectal cancer: a clinico-pathological characterization

This study has evaluated the expression of the cyclin-dependent kinase inhibitor p27^Kip1 in 89 colorectal cancers (CRCs) using immunohistochemistry and has related p27 levels to clinico-pathological characteristics, tumour cell proliferation, and the expression of other G1–S transition regulatory proteins. Low levels of p27 were common in CRCs; 11 per cent of the tumours expressed very low levels and 44 per cent had p27 labelling indices (LIs) below 50 per cent. Except for depth of tumour invasion, no significant correlation was found between p27 expression and Dukes' stage, differentiation, growth pattern, tumour type or lymphocytic infiltration. Interestingly, tumours expressing low or very low p27 LIs were predominantly found in the right colon (p=0·026). Expression of p27 was a strong predictor of survival, both in univariate and in multivariate survival analyses; patients with tumours of p27 LI less than 50 per cent had an impaired prognosis (p=0·0069). p27 expression did not correlate with tumour cell proliferation, or with expression of cyclin D1 or the retinoblastoma protein (pRb). These findings support the view that p27 not merely controls cell cycle progression, but might be associated with other mechanisms responsible for aggressive tumour behaviour in colorectal cancer. Copyright © 1999 John Wiley & Sons, Ltd.     

D-type cyclins in adult human testis and testicular cancer: relation to cell type,proliferation, differentiation,and malignancy

D-type cyclins are proto-oncogenic components of the ‘RB pathway’, a G1/S regulatory mechanism centred around the retinoblastoma tumour suppressor (pRB) implicated in key cellular decisions that control cell proliferation, cell-cycle arrest, quiescence, and differentiation. This study focused on immunohistochemical and immunochemical analysis of human adult testis and 32 testicular tumours to examine the differential expression and abundance of cyclins D1, D2, and D3 in relation to cell type, proliferation, differentiation, and malignancy. In normal testis, the cell type-restricted expression patterns were dominated by high levels of cyclin D3 in quiescent Leydig cells and the lack of any D-type cyclin in the germ cells, the latter possibly representing the only example of normal mammalian cells proliferating in the absence of these cyclins. Most carcinoma-in-situ lesions appeared to gain expression of cyclin D2 but not D1 or D3, while the invasive testicular tumours showed variable positivity for cyclins D2 and D3, but rarely D1. An unexpected correlation with differentiation rather than proliferation was found particularly for cyclin D3 in teratomas, a conceptually significant observation confirmed by massive up-regulation of cyclin D3 in the human teratocarcinoma cell line NTera2/D1 induced to differentiate along the neuronal lineage. These results suggest a possible involvement of cyclin D2 in the early stages of testicular oncogenesis and the striking examples of proliferation-independent expression point to potential dual or multiple roles of the D-type cyclins, particularly of cyclin D3. These findings extend current concepts of the biology of the cyclin D subfamily, as well as of the biology and oncopathology of the human adult testis. Apart from practical implications for the assessment of proliferation and oncogenic aberrations in human tissues and tumours, this study may inspire further research into the emerging role of the cyclin D proteins in the establishment and/or maintenance of the differentiated phenotypes. Copyright © 1999 John Wiley & Sons, Ltd.     

cyclin G2表达载体的构建及其对人胃癌细胞生长的作用

目的:构建包含人cyclinG2基因的真核表达载体,并探讨其对人胃癌细胞体外生长的作用。方法:从POE4细胞总RNA反转录产物中扩增出cyc-linG2cDNA,亚克隆至双顺反子真核表达载体pIRESneo中获得pIRES-G2重组质粒,基因转染SGC-7901细胞,G418筛选阳性克隆,免疫蛋白印迹杂交方法检测cyclinG2蛋白表达情况,平板克隆形成能力和四甲基噻唑蓝(MTT)比色法对转染后细胞的增殖活性进行分析。结果:成功构建包含cyclinG2基因真核重组表达载体pIRES-G2;转染pIRES-G2的SGC-7901细胞克隆的增殖活性明显下降。结论:cyclinG2基因转染后SGC-7901细胞体外增殖能力下降。     

人类非肿瘤性增殖中细胞周期蛋白的表达研究

目的研究具再生能力的非肿瘤组织中细胞周期蛋白(cyclins)的表达，了解cyclins在两种不同性质的细胞增殖过程中的不同表现。方法应用流式细胞术分别检测Molt-4细胞和分离自非肿瘤组织和肿瘤组织的混悬单细胞中cyclin D、E、A、B1的表达，并以Western blotting证实检测结果。结果可再生的非肿瘤组织中无法检测到cyclins的表达，而在同种组织来源的肿瘤中，一种或多种cyclins呈阳性表达。结论在细胞由良性增生转变为恶性增生的过程中，cyclins发生了导致细胞恶性转化的改变。     

cyclinD1、p16、Rb在胸腺瘤中表达及预后意义

目的：探讨ｃｙｃｌｉｎ Ｄ１、ｐ１６、Ｒｂ蛋白在胸腺瘤中表达及预后意义。方法；应用免疫组化Ｓ－Ｐ法，对５４例胸腺瘤标本进行检测。结果：ｃｙｃｌｉｎＤ１、ｐ１６，Ｒｂ蛋白在髓质型，混合型胸腺瘤中阳性表达率分别为２３．１％（３／１３）、６９．２％（９／１３），５３．９％（７／１３），器官样，普通皮质型胸腺瘤中阳性表达率分别为５０．０％（８／１６）、７５．０％（１２／１６）、７５．０％（１２／１６），高     

白血病抑制因子受体gp190细胞内区与HL-60细胞内Cdc25B激活的关系

目的：观察白血病抑制因子（LIF）受体gp190亚基完整的细胞内区和gp190胞内区C末端片段在人白血病细胞系HL－60中与细胞周期调控因子Cdc25B表达和激活的关系，进一步了解LIF引发白血病细胞增殖抑制和分化的机制。方法：用基因重组技术将gp130的细胞内区换成gp190的细胞内区，用PCR技术扩增合成gp190细胞内区C末端的一个多肽，构成嵌合体受体基因130／190及190CT片段，并分别在HL－60细胞表达。用免疫组化和Western印迹方法，分析在LIF的诱导下，细胞生长和形态与Cdc25B表达的关系。结果：转染pcDNA3.0 130/190的HL－60细胞Cdc25B的表达量降低，细胞数量减少，细胞体积增大；转染pcDNA3.0 190末端的HL－60细胞Cdc25B的表达量增高，细胞表现为增殖，细胞体积普遍减小。结论：Cdc25B表达量降低与LIF诱导引发的白血病细胞HL－60增殖抑制有关，上述效应是由gp190亚基细胞内区介导的，而pg190C末端片段或干扰LIFα受体介导的信号转导效应。     

视黄酸阻滞胎鼠腭间质细胞周期进程并诱导凋亡

目的探讨全反式视黄酸(atRA)对小鼠胚胎腭间质细胞(MEPM)细胞增殖和细胞周期的影响及其分子生物学作用机制。方法MEPM细胞取材于孕13d胎鼠腭组织。MTT比色法检测atRA对MEPM细胞增殖活力的影响;流式细胞术分析atRA对细胞周期分布的影响,并同时观察有无细胞凋亡现象发生;Western-blot检测atRA对细胞周期蛋白D和E表达的影响,并观察对视网膜母细胞瘤蛋白(Rb)磷酸化的影响。结果与溶剂对照组相比,在5~10μmol/L浓度范围内,atRA能够显著性抑制MEPM细胞增殖活力(P<0.05),并将细胞周期滞留在G0/G1期(P<0.05)。atRA对细胞周期蛋白D和E的表达及相应酶活性均表现为抑制效应。观察Rb的变化也显示,atRA降低Rb的磷酸化作用。结论atRA对腭器官发育敏感期腭间质细胞增殖活力及细胞周期的抑制作用可能是atRA诱导诱导唇腭裂的机制之一。     

p27和CyclinE在卵巢上皮性肿瘤中的表达及其临床意义

目的 :研究p2 7、CyclinE与卵巢上皮性肿瘤发生及发展的关系。方法 :采用SP免疫组织化学方法检测了 4 0例卵巢恶性上皮肿瘤、6例交界性肿瘤及 18例良性肿瘤中p2 7、CyclinE蛋白的表达情况。结果 :p2 7和CyclinE在良性肿瘤与交界性肿瘤中表达差异无显著意义。p2 7在恶性肿瘤中的表达率 (35 0 % )显著低于交界性肿瘤和良性肿瘤表达率 (77 78%、4 6 ) ,P <0 0 1;CyclinE在卵巢上皮恶性肿瘤中的表达率显著高于良性肿瘤及交界性肿瘤 ,P <0 0 1。p2 7和CyclinE蛋白表达与卵巢癌的临床分期、病理分级、淋巴结转移有关。p2 7阴性 CyclinE阳性者 ,其生物学行为极差。结论 :p2 7、CyclinE与卵巢癌的发生及发展密切相关 ,其异常表达提示卵巢肿瘤预后差